Perioperative Medical Management of Hip Surgery Patients

Key Points

The pathophysiologic surgical stress response causes widespread changes in organ function and can lead to postoperative complications. Perioperative care should be aimed at minimizing the stress response.
Preoperative assessment should include careful review of each patient's past medical history given that most adverse outcomes are due to an exacerbation of underlying medical problems rather than surgical or anesthetic complications.
Patients should be medically optimized to the extent possible prior to undergoing surgery, with appropriate treatment of any acute illness or chronic disease exacerbation.
The most important aspect of the preoperative evaluation is the cardiac assessment, which includes functional status. Patients who have a good functional capacity (at least 4 metabolic equivalents) with no cardiopulmonary symptoms or patients with low cardiac risk regardless of functional status can generally proceed directly with hip surgery.
Acute cardiac events—including ischemia, heart failure, and arrhythmias—are the most feared postoperative complications.
Ischemic heart disease is the most common cause of mortality within 90 days of hip surgery, while pneumonia is the most common inpatient postoperative medical complication.

Hip surgeries are becoming more common as our population ages. Approximately 323,000 total and partial hip replacements were performed in the United States in 2014. Fortunately, in-hospital mortality following elective hip arthroplasty is low (0.09%–0.31%) and has been decreasing. Subsequent mortality at 30 days is 0.30% and at 90 days ranges from 0.26% to 0.68%. Mirroring the general population, the main cause of death within 90 days of joint arthroplasty is ischemic heart disease.

Similarly, there were almost 305,000 hip and femur fractures or dislocations in 2014. In-hospital mortality following hip fracture is higher than for elective arthroplasty, with studies showing mortality rates ranging from 1.82% to over 10%. The higher mortality compared with hip arthroplasty is likely due to multiple factors, including older age, more comorbidities, the selection bias for healthy patients who undergo elective arthroplasty, and the physiologic stress from trauma.

Although surgical techniques have continually been refined and improved, and modern anesthesia is extremely safe, with an estimated mortality of 1 in 100,000 in the United States, patients may still suffer from medical complications. Most medical complications occur after surgery due to the significant surgical stress response, which may lead to an acute exacerbation of underlying chronic disease, especially in older patients who have diminished organ reserve capacity and comorbid medical conditions. A recent guideline from the American College of Surgeons and the American Geriatrics Society highlights the particular risks and needs of these frail elderly patients and provides recommendations for perioperative management. A review of 8593 operations (all types) showed that patient risk factors alone accounted for operative mortality for operations less than level 4, which was 95% of the patients studied. The study authors found that “risk factors that patients bring to the operating room account for the majority of operative deaths.”

This chapter explains the surgical stress response, reviews the components of the preoperative evaluation, discusses techniques to help medically optimize patients, and provides a symptom-based approach to diagnose and treat postoperative medical complications.

Basic Science

The Surgical Stress Response

The human body responds to the stress of an injury through a remarkable physiologic process that activates the sympathetic nervous and endocrine systems and promotes an increased inflammatory response with decreased immune function (despite an initial increased production of reparative leukocytes). The magnitude and duration of these effects is directly proportional to the degree of injury, with the overall goals of maintaining intravascular volume for cardiovascular homeostasis and increasing catabolism to provide energy sources. While the stress response is appropriate and can prolong survival following an accidental injury, it can be counterproductive following the “controlled injury” of surgery.

Many of the initial surgical stress response effects are attenuated by anesthesia and opioids but may manifest postoperatively. As a result, most postoperative complications are due to the subsequent increased demands on organ function in the setting of preexisting comorbid conditions rather than from anesthetic or surgical effects. The overall stress response may persist for up to 7 days ; knowledge of the duration of individual organ or system changes can be helpful in distinguishing expected physiologic changes from pathologic complications. For example, a study of total knee arthroplasty (TKA) patients by Andres et al. reported fevers of ≥ 38.5°C in 10 of 20 patients in the first 72 hours after surgery. The fevers were “at least partly the result of surgical site inflammation and subsequent local and systemic release of the endogenous pyrogen interleukin-6…tests aimed at determining the cause of fevers in the 72 hours after TKA are not warranted unless findings on physical examination suggest a specific source.” Dorman et al. showed that interleukin-6 peaks at 24 hours but is still slightly elevated at 72 hours. Thus, although a postoperative fever up to 38.5°C may be expected within the first 72 hours, prolonged fevers and febrile patients with infectious findings should have further workup. Awareness of the surgical stress response can also be helpful in diagnosing complications based on when they are most likely to occur. For instance, catecholamines are increased for 24 to 48 hours following surgery and are associated with an increased incidence of myocardial infarction (MI).

A multimodal approach may help decrease complications related to the stress response by using techniques such as minimally invasive surgery, neural blocks with local anesthetics, intraoperative body heat conservation, early enteral nutrition and ambulation, and minimal use of surgical drains and nasogastric tubes. Adequate postoperative pain control may also help attenuate the effects of the stress response.

The Preoperative Evaluation

The preoperative evaluation is an important aspect of any surgical procedure. It should assess the patient's current medical status and provide risk identification as well as recommendations to reduce risk. The evaluation also provides an opportunity to ensure that acute conditions/exacerbations are treated and chronic medical conditions are optimized. The preoperative evaluation is not to simply declare the patient “clear for surgery” but is a multidisciplinary effort that includes input from the surgeon, anesthesiologist, and often a medical consultant. The evaluation should be performed prior to the day of surgery for patients with high severity of disease or for patients with low severity of disease undergoing highly invasive surgical procedures.

The history and physical examination serve as the cornerstone of the preoperative evaluation. Information should focus on pertinent past medical history, current review of systems/symptoms, physical examination (including airway evaluation), and current medications and drug allergies. The most important aspect of the history and physical is the cardiac assessment, which includes functional status. Patients with no acute illness or exacerbation who have a good functional capacity with no cardiopulmonary symptoms can generally proceed directly with hip surgery. Patients with poor functional capacity require further assessment and, depending on cardiac risk, may need preoperative cardiac stress testing if it will change management. Patients with low cardiac risk, even if they have a poor or unknown functional status, can generally proceed directly with hip surgery without further cardiac workup.

The preoperative evaluation should also include any recommendations for other testing before surgery, although preoperative tests should not be ordered routinely but rather should be obtained for purposes of guiding or optimizing perioperative management. The benefit of any testing or medical treatment must be weighed against the risks of delays in surgical treatment, especially for hip fracture patients requiring urgent or time-sensitive surgery. In general, operative repair should be performed when the patient is medically optimized. Moderate evidence supports that hip fracture surgery within 48 hours of admission is associated with better outcomes. A recent retrospective study found that increased wait times were associated with a greater risk of 30-day mortality and other medical complications. The study authors suggested that “a wait time of 24 hours may represent a threshold defining higher risk,” and such timing was felt to be important according to an accompanying editorial.

It is unclear which type of anesthesia, general or neuraxial (spinal or epidural), leads to better outcomes following hip surgery, although a recent retrospective study showed that neuraxial anesthesia for total hip arthroplasty (THA) was associated with a decrease in deep surgical site infection rates, hospital length of stay, and rates of postoperative cardiovascular and pulmonary complications when compared with general anesthesia. This topic remains controversial—decisions about the specific type of anesthesia should be determined by the anesthesiologist.

Of note, all hip fracture patients should be evaluated and treated for osteoporosis. The authors recommend checking 25-hydroxy vitamin D levels in these patients. A bisphosphonate should be started to help reduce the risk of a subsequent fracture.

History

Past Medical History and Review of Systems

Review the patient's known medical problems and assess each for optimization/stability, including new and chronic symptoms. A mnemonic (“The ABCs,” Box 24.1 ), adapted from Mayo Clinic teaching resources, can serve as a reminder of the most important questions to ask each patient.

Box 24.1

The ABCs of Preoperative Medical History

A
Activity level (functional status in metabolic equivalents [METS])
- Airway concerns
- Alcohol use/abuse
- Allergies (drugs, latex)
- Anesthesia complications (malignant hyperthermia, postoperative nausea/vomiting, other reactions)
B
Bleeding disorder (inherited or acquired thrombophilia, chronic antiplatelet or anticoagulation therapy)
C
Cardiac history (coronary disease, valvular disease, heart failure, pacemaker)
- Cervical spine instability
- Clots (deep vein thrombosis [DVT] or pulmonary embolism [PE])
- Consent for blood transfusion, if indicated
- Corticosteroid use that could lead to adrenal suppression
D
Deficit (preexisting neurologic disease, such as focal limb weakness or seizure disorder)
- Dementia
- Diabetes mellitus
- Drug abuse
E
Embolic history (stroke or transient ischemic attack)
F
Family history of anesthesia complications (malignant hyperthermia)
- Fetus (pregnant)
G
Gastroesophageal reflux disease
- Glaucoma
H
Height and weight
- Hepatitis or HIV
- Hypoxia (pulmonary disease, pulmonary hypertension, obstructive sleep apnea)

Patients who need emergent surgery should proceed directly to the operating room with expedited evaluation as allowed by their clinical condition, such as determining clinical risk factors that may influence perioperative management. Surgery should be performed with appropriate monitoring and management strategies based on the clinical assessment. On the other hand, patients who are undergoing elective hip surgery and who have an acute coronary syndrome (ST-segment or non–ST-segment MI, or unstable angina) should have emergent cardiology evaluation and treatment prior to surgery. Other active cardiac conditions—such as decompensated heart failure, significant arrhythmias (including high-grade atrioventricular block, symptomatic ventricular arrhythmias, supraventricular arrhythmias with ventricular tachycardia, or symptomatic bradycardia), or severe valvular disease—should also have appropriate evaluation and treatment prior to surgery. Likewise, any symptoms suggestive of an acute infection or disease exacerbation (e.g., asthma) also require further evaluation and treatment prior to surgery.

Special attention should be given to the patient's airway and any previous anesthesia complications or adverse reactions. For patients with a history of penicillin allergy, consider referral for formal allergy consultation and penicillin skin testing if beta-lactam therapy is being considered. Always review the patient's alcohol and drug abuse history and be alert for withdrawal syndromes postoperatively. Patients who smoke should be advised to stop smoking as early as possible before surgery to reduce the risk of postoperative complications. Patients with obesity have an increased incidence of perioperative complications (including infection and dislocation), increased blood loss, and, for patients with severe obesity (body mass index [BMI] ≥ 40 kg/m ² ), longer operative times, but studies on functional outcomes are mixed. Patients with a higher BMI tend to undergo arthroplasty at a younger age, which is associated with having revision at an older age when there is a higher risk of complications. For patients who plan to undergo both joint arthroplasty and bariatric surgery, having the bariatric surgery first seems to improve outcomes.

Physical Examination

A focused review of systems and preoperative physical examination should be performed on all patients. At a minimum, the examination should include documentation of vital signs and an assessment of the airway, heart, and lungs. Important findings that may require further evaluation are discussed here.

Vital Signs.

Measure and document current vital signs, including temperature, blood pressure, heart rate and rhythm, respiratory rate and pattern, oxygen saturation, and height and weight.

Airway.

Patients with a small mouth, micrognathia, limited neck range of motion, or poorly visualized posterior oropharynx (Mallampati class III or IV as shown in Fig. 24.1 ) may be harder to intubate and establish an airway; thus, the anesthesiologist should be alerted to a potential “difficult airway.” Also, patients who are edentulous or have a full beard may be difficult to oxygenate with a face mask; thus, these conditions should be noted as well.

Fig. 24.1, Mallampati Classification. Class I: Full visibility of tonsils, uvula, and soft palate. Class II: Visibility of hard and soft palate, upper portion of tonsils and uvula. Class III: Soft and hard palate and base of the uvula are visible. Class IV: Only hard palate is visible.

Cardiac.

Ask patients if they have any chest pain/pressure or dyspnea at rest or with activity, palpitations, orthopnea, or syncope. While ischemic heart disease has a 30-day mortality after noncardiac surgery of 2.9%, heart failure has a higher mortality of 9.2% in ischemic heart disease and 9.3% in nonischemic heart disease. However, as shown in Fig. 24.2 , a recent retrospective analysis of over 10 million major noncardiac surgeries in the United States found that orthopedic surgeries are associated with fewer major adverse cardiovascular and cerebrovascular events (1595 per 100,000 surgeries) than vascular surgeries (7707 per 100,000), thoracic surgeries (6514), neurosurgeries (4626), and general surgeries (3862).

Assess the heart rate and rhythm, paying particular attention to bradycardia or tachycardia and any irregularity that could indicate atrial fibrillation or a conduction block. Atrial fibrillation was found in a study by van Diepen and colleagues to have a higher 30-day mortality (6.4%) after noncardiac surgery than ischemic heart disease (2.9%), although these were patients who were previously hospitalized for atrial fibrillation, thus, they may have been a higher-risk cohort.

Listen for any significant cardiac murmurs. Patients with suspected moderate or greater degrees of valvular stenosis or regurgitation should undergo echocardiography to quantify the severity of valvular disease, calculate systolic function, and estimate right heart pressures. Aortic stenosis, which typically causes a harsh systolic murmur (occurring between the first and second heart sounds), has a 30-day mortality after noncardiac surgery ranging from 1.2% if asymptomatic to 2.8% if symptomatic. This murmur characteristically radiates to one or both carotid arteries. Note that the physical examination often underestimates cardiac dysfunction in patients with severe obesity (BMI ≥ 40 kg/m ² ).

Respiratory.

Ask patients if they have dyspnea, cough with sputum, or wheezing and if these symptoms are baseline, worse than baseline, or new. Listen for inspiratory crackles (rales), which could indicate pulmonary edema or infection, and wheezes, which can be found in asthma, chronic obstructive pulmonary disease (COPD), and pulmonary edema. Patients with COPD commonly have decreased breath sounds and a prolonged expiratory phase of respiration.

Gastrointestinal.

Ask patients if they have any nausea, vomiting, abdominal pain, constipation, or diarrhea. The abdomen should be soft, nontender, and nondistended, with normal bowel sounds. Special note should be made of findings suggestive of liver disease, such as ascites, since cirrhotic patients are at increased risk for medical and surgical complications and mortality following hip surgery.

Vascular.

Look for evidence of elevated jugular venous pressure and lower extremity edema, which could indicate increased intravascular volume related to right heart failure. Diminished peripheral pulses may be due to peripheral vascular disease, which could impair wound healing.

Neurologic/Psychiatric.

Any preexisting neurologic deficit should be documented along with conditions such as a seizure disorder, dementia, or history of delirium.

Skin.

Any skin ulcers should be documented and may need treatment prior to surgery, particularly if there is evidence of infection.

Functional Status

Patients who are highly functional and asymptomatic are at lower risk for perioperative cardiac complications. Functional status is quantified in terms of metabolic equivalents (METs), as shown in Table 24.1 .

TABLE 24.1

Duke Activity Status Index

From Hlatky MA, Boineau RE, Higginbotham MB, et al. A brief self-administered questionnaire to determine functional capacity (the Duke Activity Status Index). Am J Cardiol. 1989;64:651–654.

Activity	Weight
Can you…
1. take care of yourself, that is, eating, dressing, bathing, or using the toilet?	2.75
2. walk indoors, such as around your house?	1.75
3. walk a block or two on level ground?	2.75
4. climb a flight of stairs or walk up a hill?	5.50
5. run a short distance?	8.00
6. do light work around the house like dusting or washing dishes?	2.70
7. do moderate work around the house like vacuuming, sweeping floors, or carrying in groceries?	3.50
8. do heavy work around the house like scrubbing floors or lifting or moving heavy furniture?	8.00
9. do yardwork like raking leaves, weeding, or pushing a power mower?	4.50
10. have sexual relations?	5.25
11. participate in moderate recreational activities like golf, bowling, dancing, doubles tennis, or throwing a baseball or football?	6.00
12. participate in strenuous sports like swimming, singles tennis, football, basketball, or skiing?	7.50

Patients who can achieve at least 4 METs without cardiopulmonary symptoms have adequate functional capacity and generally may proceed directly to hip surgery without preoperative cardiac testing, assuming no acute symptoms. However, it is often difficult to estimate functional capacity in orthopedic patients who may have joint pain that limits ambulation. In this case, ask about other activities listed in the Duke Activity Status Index (see Table 24.1 ) to estimate a patient’s METs. It is easiest to use the online calculator ( https://www.mdcalc.com/duke-activity-status-index-dasi ) to calculate a patient’s METs.

Patients who cannot achieve 4 METs or who have an unknown functional status should be further assessed to determine their risk of a perioperative major adverse cardiac event (MACE). Patients considered at low risk—those with an estimated risk for MACE of less than 1%—do not need preoperative stress testing regardless of functional status, assuming no acute symptoms. One of the simplest tools to calculate the risk of MACE is the Revised Cardiac Risk Index (RCRI), which assigns one point each for diabetes mellitus treated with insulin, chronic kidney disease with creatinine greater than 2, ischemic heart disease, cerebrovascular disease, heart failure, or for a high-risk surgery (suprainguinal vascular, intraperitoneal, or intrathoracic). A score of 0 or 1 has been considered low risk based on the original RCRI (0.4% and 0.9%, respectively). However, a 2017 Canadian guideline calculated higher risk estimates of 3.9% and 6.0% for RCRI scores of 0 and 1. This is in contrast to a prospective cohort reevaluation of the RCRI with 9519 consecutive patients, which calculated values of 0.5% and 2.6% for RCRI scores of 0 and 1, respectively. Also, a large systematic review of 24 studies (792,740 patients) showed that the RCRI discriminated moderately well between patients at low versus high risk for cardiac events after mixed noncardiac surgery, although it did not perform well at predicting cardiac events for vascular surgery or for mortality with any type of surgery; note that the authors did not evaluate calibration or risk stratification capacity. Two online calculators are also available to estimate the risk of MACE, the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) Surgical Risk Calculator (http://riskcalculator.facs.org/RiskCalculator/), as discussed in the American College of Cardiology/American Heart Association (ACC/AHA) guidelines, and the Gupta Perioperative Cardiac Risk Calculator ( http://www.qxmd.com/calculate/calculator_245/gupta-perioperative-risk ), which is simple to use.

Consideration can be given for preoperative cardiac stress testing in patients with an unknown or poor functional status (< 4 METs) and at least a 1% risk of MACE if it will impact patient decision-making or perioperative care . Always ask if a patient has had a recent cardiac stress test, especially if the patient is nonambulatory or minimally active. For patients with an abnormal stress test, consider coronary angiography and revascularization, depending on the extent of the abnormal test. Likewise, revascularization before noncardiac surgery is recommended in circumstances in which revascularization is indicated according to existing clinical practice guidelines.

Otherwise, it is not recommended that patients undergo routine coronary revascularization before noncardiac surgery exclusively to reduce perioperative cardiac events. According to the ACC/AHA, “PCI [percutaneous coronary intervention] should not be performed as a prerequisite in patients who need noncardiac surgery unless it is clearly indicated for high-risk coronary anatomy (e.g., left main disease), unstable angina, MI, or life-threatening arrhythmias due to active ischemia amenable to PCI. If PCI is necessary, then the urgency of the noncardiac surgery and the risk of bleeding and ischemic events, including stent thrombosis, associated with the surgery in a patient taking DAPT [dual antiplatelet therapy] need to be considered.”

Fig. 24.3 shows a simple cardiac assessment algorithm that summarizes these recommendations. This algorithm is based on the detailed algorithm from the ACC/AHA 2014 Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery. Patients with significant cardiopulmonary disease—including heart failure, pulmonary hypertension, and valvular disease—may require further evaluation based on symptoms and findings.

Fig. 24.3, Preoperative cardiac evaluation algorithm.

Current Medications

Obtain an accurate list of all medications, dosing, and schedule, including over-the-counter and herbal medications. Table 24.3 provides suggestions for which medications should be taken and which ones should be held the morning of surgery. Some of these recommendations are based on expert opinion at the authors’ institution; practitioners should be aware of local preferences and recommendations.

TABLE 24.3

Recommendations for Medication Dosing the Morning of Orthopedic Surgery

Drug Class	Take	Hold
Cardiac	Beta blockers	Diuretics
	α ₂ -agonists (i.e., clonidine)	ACE inhibitor ^a
	Calcium channel blockers	ARB ^a
	Digoxin	Fibrates (stop the day before)
	Isosorbide mono- and dinitrate	Niacin (stop the day before)
	Statins
Pulmonary	Nebulizer/MDI
	Leukotriene inhibitors
	Inhaled and systemic corticosteroids
Gastrointestinal	Proton pump inhibitors
	H2-blockers
	Stool softeners
Genitourinary	α ₁ -antagonists (e.g., tamsulosin)	Tolterodine
		Oxybutynin
Endocrine	Levothyroxine	Sulfonylureas
	Corticosteroid ^b	Metformin ^c
		Insulin ^d
		Thiazolidinediones
		Hormone replacement therapy (hold 4 wk preop)
		Noninsulin injectables
Psychiatric	SSRI unless high bleeding risk	MAOI (hold 2 wk preop ^e )
	Benzodiazepine	Tricyclic antidepressants (taper 7–14 days before surgery) ^f
	Antipsychotics ^g
	Lithium
Neurologic	Antiepileptic drugs
	Carbidopa/levodopa ^e
Rheumatoid	Methotrexate
	Leflunomide (hold 2 wk preop)
	Hydroxychloroquine
	Azathioprine
	Sulfasalazine
	NSAIDs	(hold 3 days preop)
Pain	Opioids
	NSAIDs	(hold 3 days preop)
	Tylenol

ACE, Angiotensin-converting enzyme; ARB, angiotensin-receptor blocker; MAOI, monoamine oxidase inhibitor; MDI, metered-dose inhaler; NSAIDs, nonsteroidal antiinflammatory drugs; SSRI, selective serotonin reuptake inhibitor.

a We generally hold ACE and ARB the morning of surgery, but decision should be based on blood pressure and indication for treatment (may need to continue to treat heart failure or poorly controlled hypertension). Ideally, ACE and ARB should be resumed within 48 hours.

b Patients taking chronic steroids may benefit from perioperative stress-dose steroids.

c Metformin should be held starting 1 day before surgery and resumed on post-op day 2 to 3, assuming adequate kidney function and no heart failure exacerbation.

d Insulin dose should be adjusted the morning of surgery depending on time of day and duration of surgery. Typically, one-half the usual morning dose is given for patients taking NPH (Neutral Protamine Hagedorn). Once-daily basal insulin (glargine, detemir, degludec) can be continued, but we suggest the dose be decreased by 25%.

e Discuss with anesthesiologist; it may be safe to continue.

f Tricyclics generally can be continued if severe depression and low risk for cardiac arrhythmias.

g Use cautiously if risk for exacerbation of psychoses; should discontinue if ECG shows prolonged QTc.

In general, most prescription medications should be continued perioperatively, especially drugs with known withdrawal syndromes (such as beta blockers, clonidine, or benzodiazepines) and should be taken with sips of water the morning of surgery. However, certain drugs should be held the morning of surgery, and herbal medications should be held due to possible drug-drug interactions with anesthetic agents and concerns for increased bleeding risk. Among others, bleeding can be potentiated by the “G” herbal medications: garlic (hold for 7 days), ginger (hold for 2 weeks), ginkgo biloba (hold at least 36 hours), and ginseng (hold for 7 days). Aspirin and P2Y ₁₂ inhibitors (e.g., clopidogrel, ticagrelor, and prasugrel) each can increase the risk of surgical bleeding, but they are essential treatment for patients with a recent coronary stent (especially drug-eluting stents) and may be given for other indications, including stroke (although prasugrel should not be given to patients with a prior stroke or transient ischemic attack). In cases in which the aspirin and P2Y ₁₂ inhibitor must be stopped because of high risk of surgical bleeding, it appears that the optimal time to hold aspirin is 7 days before surgery. Clopidogrel and ticagrelor should be held for 5 days prior to surgery and prasugrel for 7 days. However, due to the high mortality from in-stent coronary thrombosis when off antithrombotic medications, the surgical team should consult with a cardiologist for patients with recent coronary stent placement (within 3–12 months for drug-eluting stents depending on the indication) before these medications are stopped. If the P2Y ₁₂ inhibitor must be stopped, aspirin should be continued if at all possible.

Preoperative Testing

There is insufficient evidence that preoperative testing affects surgical outcomes. Thus, evaluation should be limited to those tests that may change the risk of surgery, especially if the underlying disease can be treated, or to provide a baseline that will be used to monitor a clinical condition or treatment perioperatively. Because there is a risk of false-positive results or minor abnormalities that will not influence surgical outcome, tests should be ordered selectively rather than routinely. The indications for tests should be documented, and any abnormal test result must be addressed. Laboratory tests obtained within the previous 4 months should safely provide adequate information unless there has been an interim change in clinical status or in medications that could affect lab values (such as electrolytes) or if the test results may affect the selection of anesthetic (e.g., regional anesthesia in the setting of anticoagulation).

Laboratory Tests

A complete blood count (CBC) with hemoglobin, white cell count, and platelet count should be obtained in patients with a history or symptoms of anemia or infection, history of bleeding diathesis, or if the surgical procedure may lead to significant blood loss that could require a transfusion. Likewise, a surgical type and cross-match should be obtained if there is concern that the patient may have significant blood loss. A baseline platelet count is helpful for patients who will be on heparin perioperatively. We recommend assessing kidney function (serum creatinine) in all patients undergoing hip surgery. Electrolytes should be checked in patients with chronic kidney disease or heart failure and in those taking digoxin or medications that affect electrolytes such as diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin-receptor blockers (ARBs), or nonsteroidal antiinflammatory drugs (NSAIDs). An international normalized ratio (INR) can be obtained in persons on warfarin therapy and those with a history of bleeding diathesis, liver disease, or malnutrition. A fasting glucose should be checked in diabetics and persons at high risk for diabetes. A pregnancy test should be obtained for female patients of childbearing age. The ASA recommends obtaining a urinalysis in patients who will have an implanted prosthesis or in patients who have symptoms of a urinary tract infection (UTI). However, it is not clear whether treatment of UTIs or asymptomatic bacteriuria prior to surgery decreases the risk of surgical infection, as data have been conflicting. In particular, the study by Koulouvaris et al. suggests that there is no clear evidence between treated preoperative or postoperative UTI and prosthetic joint infection. The authors of a literature review and synthesis in UpToDate favor only evaluating symptomatic patients and treating UTIs instead of obtaining routine urine studies in asymptomatic patients prior to joint arthroplasty, as they would not treat asymptomatic bacteriuria.

Electrocardiogram

It is reasonable to obtain a preoperative electrocardiogram (ECG) for patients with known coronary heart disease (CHD), significant arrhythmia, peripheral arterial disease, cerebrovascular disease, or other significant structural heart disease who are undergoing intermediate-risk procedures such as hip surgery. It is also reasonable to obtain an ECG for patients with severe obesity (BMI ≥ 40 kg/m ² ). For stable patients, a new ECG should not be necessary if one is available within the previous 1 to 3 months prior to elective surgery.

Chest Radiographs and Spirometry

In general, these tests should not be obtained routinely for predicting risk of postoperative pulmonary complications. However, chest radiographs may be appropriate in patients with a previous diagnosis of cardiopulmonary disease or severe obesity, and should be obtained for patients with acute or unstable symptoms. Pulmonary function tests can be obtained for patients with COPD or asthma when it is unclear whether the patient is at best baseline or for patients with unexplained dyspnea or exercise intolerance.

Cervical Spine Radiographs

Patients with long-standing rheumatoid arthritis have a high prevalence of atlantoaxial subluxation, which may be asymptomatic. Patients with rheumatoid arthritis who have neck pain or neurologic symptoms or who are asymptomatic but are at high risk for subluxation should have preoperative flexion and extension radiographs prior to intubation, although abnormal findings may not influence choice of airway management. Patients with ankylosing spondylitis are at risk for atlantodental ossification and ankylosis ; thus, they may also benefit from preoperative cervical spine radiographs. Patients with Down syndrome may have cervical spine instability produced by ligamentous laxity and/or skeletal anomalies. For Down syndrome patients who have suspicion of signs or symptoms consistent with cervical cord compression, radiologic evaluation and surgical consultation should be considered before proceeding with elective surgery, but it is not clear whether asymptomatic patients should also have evaluation.

Risk Reduction and Medical Optimization

Identification of risk factors for postoperative complications can help guide preoperative evaluation and risk-reduction strategies. Likewise, it is important to assess each patient's history and symptoms before surgery to help determine whether there is a new acute process or an exacerbation of a chronic illness. Patients undergoing surgery should be at their best baseline regarding comorbid medical conditions, functional status, and nutritional status. This does not mean that each chronic condition must be “cured,” but if there is an acute process or exacerbation, elective procedures may need to be deferred. On the other hand, for urgent procedures such as hip fractures, the important question is whether surgery should be delayed (and for how long) to allow medical optimization.

Multiple studies have identified risk factors for postoperative complications or mortality in hip surgery patients. Memtsoudis et al. found that advanced age is the single most important risk factor for postoperative complications following hip and knee arthroplasty, along with comorbid medical conditions. Maxwell and colleagues noted a number of independent predictors of 30-day mortality for hip fracture patients: age older than 65 years, male sex, at least two comorbidities, low mini-mental test score, admission hemoglobin concentration less than 10 g/dL, living in an institution, and presence of malignant disease. Choi and colleagues found that low hemoglobin, low serum protein or serum albumin levels, high serum creatinine levels, and ASA classification (see Table 24.2 ) were associated with increased 6-month all-cause mortality. They also reviewed geriatric assessment domains and noted that a low Mini-Mental State Examination (Korean version) score, dependency in instrumental activities of daily living, a higher Charlson comorbidity index, risk of falling, malnutrition, and thinner mid-arm circumference were associated with increased 6-month all-cause mortality.

TABLE 24.2

American Society of Anesthesiologists (ASA) Physical Status (PS) Classification System

ASA PS Classification	Definition	Examples, Including, But Not Limited To:
ASA I	A normal healthy patient	Healthy, nonsmoking, no or minimal alcohol use
ASA II	A patient with mild systemic disease	Mild diseases only, without substantive functional limitations. Examples include (but not limited to): current smoker, social alcohol drinker, pregnancy, obesity (30 < BMI < 40), well-controlled DM/HTN, mild lung disease
ASA III	A patient with severe systemic disease	Substantive functional limitations; One or more moderate to severe diseases. Examples include (but not limited to): poorly controlled DM or HTN, COPD, morbid obesity (BMI ≥ 40), active hepatitis, alcohol dependence or abuse, implanted pacemaker, moderate reduction of ejection fraction, ESRD undergoing regularly scheduled dialysis, premature infant PCA < 60 wk, history (> 3 mo) of MI, CVA, TIA, or CAD/stents.
ASA IV	A patient with severe systemic disease that is a constant threat to life	Examples include (but not limited to): recent (< 3 mo) MI, CVA, TIA, or CAD/stents, ongoing cardiac ischemia or severe valve dysfunction, severe reduction of ejection fraction, sepsis, DIC, ARDS, or ESRD not undergoing regularly scheduled dialysis.
ASA V	A moribund patient who is not expected to survive without the operation	Examples include (but not limited to): ruptured abdominal/thoracic aneurysm, massive trauma, intracranial bleed with mass effect, ischemic bowel in the face of significant cardiac pathology, or multiple organ/system dysfunction.
ASA VI	A declared brain-dead patient whose organs are being removed for donor purposes

Note: The addition of “E” (e.g., “ASA IIIE”) would denote emergency surgery (an emergency is defined as existing when delay in treatment of the patient would lead to a significant increase in the threat to life or body part).

ARDS, Acute respiratory distress syndrome; BMI, body mass index; CAD, coronary artery disease; CVA, cerebrovascular accident; COPD, chronic obstructive pulmonary disease; DIC, disseminated intravascular coagulation; DM, diabetes mellitus; ESRD, end-stage renal disease; HTN, hypertension; MI, myocardial infarction; PCA, postconceptional age; TIA, transient ischemic attack.

Cardiac

Postoperative cardiac complications include myocardial ischemia/infarction, heart failure, hemodynamic instability, and arrhythmias. The key points are to distinguish acute or unstable conditions from those that are chronic and stable and to estimate a patient's risk of MACE.

Risk Factors.

Approximately 30% of adults undergoing surgery each year in the United States have coronary artery disease (CAD). The two most important risk factors are male gender and advancing age; other risk factors include hypertension, hypercholesterolemia, diabetes mellitus, cigarette smoking, obesity, sedentary lifestyle, family history of premature CAD (men less than 55 and women less than 65 years old), and psychological factors such as Type A personality and stress.

Recommendations

Continue current cardiac medications perioperatively, although diuretics are typically held on the morning of surgery. ACE inhibitors and ARBs may increase the risk of postinduction hypotension, leading to acute kidney injury. Thus, we also hold these medications the morning of surgery, particularly if the patient has low blood pressure, chronic kidney disease, or if large perioperative fluid shifts are anticipated. Alternatively, patients who normally take an ACE inhibitor or ARB may need to take it preoperatively if their blood pressure is significantly elevated. Resuming ARBs within 48 hours following surgery is associated with decreased mortality ; we try to resume ARBs and ACE inhibitors as soon as hemodynamics, volume status, electrolytes, and kidney function allow.
Strive to minimize effects of the surgical stress response and conditions that may lead to coronary ischemia, including hypertension, tachycardia, pain, anxiety, hypoxemia, anemia, volume depletion or overload, fever, urinary retention, or constipation.
Be vigilant for withdrawal syndromes that may lead to increased cardiac stress.
Patients at high risk for cardiac complications may benefit from further preoperative evaluation and/or postoperative care in a monitored setting.
Patients already taking beta blockers should continue taking them in the perioperative period.
Patients with decompensated heart failure should be diuresed and at their baseline volume status before undergoing orthopedic surgery.
Patients with severe aortic stenosis may benefit from aortic valve replacement prior to orthopedic surgery. According to the ACC/AHA, “valvular intervention before elective noncardiac surgery is effective in reducing perioperative risk.”
Patients with chronic arrhythmias should be hemodynamically stable and rate controlled (generally < 100 beats per minute). Patients with atrial fibrillation are often on anticoagulation that may need to be discontinued based on expected surgical bleeding risk. These patients may benefit from “bridging” with heparin or low-molecular-weight heparin according to cardioembolic stroke risk. Patients with ventricular arrhythmias may need cardiac evaluation preoperatively.
Any unstable patient should be hospitalized preoperatively for evaluation and treatment.

Pulmonary

Postoperative pulmonary complications include atelectasis, hypoxemic or hypercarbic respiratory failure, pneumonia, COPD exacerbation, aspiration, and prolonged mechanical ventilation.

Risk Factors.

Patient-related risk factors include age greater than or equal to 65 years, COPD, smoking, obstructive sleep apnea (OSA), pulmonary hypertension, heart failure, ASA class greater than 2, and a low serum albumin level (< 3 g/dL), but not obesity. Although most orthopedic procedures are not as high risk for postoperative pulmonary complications as aortic, thoracic, or upper abdominal surgery, prolonged operative time of 3 to 4 hours (not specific for orthopedic surgeries) is an independent risk factor. Risk factors for aspiration, which occurs in up to 0.01% to 0.06% of anesthetized patients at the time of anesthesia induction and intubation, include advanced age, gastroesophageal reflux disease (GERD)/hiatal hernia, obesity, pregnancy, and conditions such as diabetes that may predispose to delayed gastric emptying. Of note, aspiration related to anesthesia induction or intubation may lead to pulmonary complications, but complications are unlikely if no signs or symptoms are seen within 2 hours of the aspiration event.

OSA may lead to hypoxemia, hypercarbia, and cardiovascular dysfunction. Patients with OSA also may have difficulty with airway management, including intubation. The Society of Anesthesia and Sleep Medicine suggests consideration of additional evaluation for preoperative cardiopulmonary optimization in patients with a high probability of OSA and when there are findings of uncontrolled systemic conditions or problems with ventilation or gas exchange. Screening tools such as the STOP-Bang score can be used to help identify patients at risk for OSA. However, there is inadequate evidence in the literature to recommend the use of sleep testing such as polysomnography in the preoperative period.

Recommendations

Patients who smoke should be advised to stop smoking as early as possible before surgery.
Patients with acute respiratory symptoms such as chest tightness or wheezing should be given aggressive bronchodilator therapy with the option of preoperative systemic corticosteroid therapy. A short course of systemic steroids is unlikely to delay wound healing or increase perioperative infection risk.
Patients with evidence of a pulmonary infection may need treatment with antibiotics.
The I COUGH (Incentive spirometry, Coughing/deep breathing, Oral care, Understanding/education, Getting out of bed at least three times daily, and keeping the Head of the bed elevated) program, which reduced the incidence of postoperative pneumonia and unplanned intubation among general and vascular surgery patients, may also be helpful for orthopedic patients.
Avoid placing nasogastric tubes if possible, although they may be used selectively for postoperative nausea or vomiting, inability to tolerate oral intake, or symptomatic abdominal distention.
Patients with GERD/hiatal hernia should be given acid-blocking medications prior to surgery to decrease aspiration risk.
All patients should be screened for OSA prior to surgery. Elective surgery should be deferred for evaluation and treatment for patients with untreated or partially treated OSA or suspected OSA who have significant or uncontrolled systemic disease or conditions such as hypoventilation syndrome, severe pulmonary hypertension, or resting hypoxemia in the absence of other cardiopulmonary disease.
Opioids should be used cautiously in OSA patients, and continuous opioid basal infusions (for patient-controlled analgesia) should be avoided or used with extreme caution. Nonopioid analgesia modalities—such as regional nerve blocks, NSAIDs, and ice—should be considered.
Patients with OSA should have continuous monitoring with pulse oximetry and observation as long as they remain at increased perioperative risk. If possible, they should be placed in a nonsupine position during their recovery.
Patients with OSA should be given supplemental oxygen until they are able to maintain their baseline oxygen saturation while breathing room air, acknowledging that supplemental oxygen may increase the duration of apneic episodes and may hinder detection of transient apnea, hypoventilation, and atelectasis by pulse oximetry.
Patients who have previously been diagnosed with OSA and who use positive-pressure airway devices should bring their units to the hospital or should know their device settings to allow hospital personnel to set up a comparable unit.
Regional analgesic techniques should be considered for patients with OSA to reduce or eliminate the requirement for systemic opioids.
Patients with hypercarbia should be monitored closely for symptoms such as somnolence or confusion that could indicate worsening CO ₂ retention, and supplemental oxygen may need to be minimized while avoiding hypoxemia.

Gastrointestinal

Gastrointestinal complications following hip surgery include postoperative nausea and vomiting (PONV), postoperative ileus (POI), and acute colonic pseudo-obstruction (Ogilvie syndrome).

Risk Factors.

Risk factors for PONV include female sex, prior history of PONV or motion sickness, nonsmoking status, younger age, general versus regional anesthesia, volatile anesthetics and nitrous oxide, postoperative opioids, and duration of surgery, with the most likely causes being volatile anesthetics, nitrous oxide, and postoperative opioids. Risk factors for POI include the surgical stress response (sympathetic hyperactivity, systemic endocrine response, and production of endogenous opioids and inflammatory cytokines), increased surgical blood loss (possibly contributing to a heightened inflammatory response), and factors related to perioperative care, such as general anesthesia and the use of opioid medications. Preexisting gastrointestinal disease such as Crohn disease as well as decreased perioperative physical activity can also contribute to POI, which can cause abdominal symptoms and increased hospital length of stay. Risk factors for acute colonic pseudo-obstruction in one study of patients undergoing hip or knee arthroplasty included advanced age, male sex, previous abdominal surgery, and medications that affect bowel motility (including opioids, phenothiazines, tricyclic antidepressants, calcium channel blockers, H ₂ -receptor blockers, and anticholinergics). Slow postoperative mobility and revision hip arthroplasty were also found to be significant risk factors in a study by Petrisor and associates. Other risk factors may include hypothyroidism, diabetes mellitus, electrolyte abnormalities, uremia, and preexisting gastrointestinal disease.

Patients with liver disease deserve special mention given their increased risk of perioperative complications and mortality. Acute hepatitis (typically, viral or drug-induced) may present with symptoms of nausea, vomiting, anorexia, jaundice, and dark urine. Elective surgery should be deferred until patients demonstrate symptomatic and biochemical improvement. These patients should be advised to avoid alcohol and hepatotoxic medications, and they should be evaluated by a hepatologist. Chronic liver disease is often known before surgery is performed but may present undiagnosed with fatigue, malaise, abdominal pain, jaundice, ascites, encephalopathy, and abnormal liver tests. These patients are at high risk for early complications and limited prosthesis longevity.

Surgery should be delayed in patients with decompensated cirrhosis, which may manifest with encephalopathy and/or ascites. Tiberi and colleagues found that a MELD (Model for End-Stage Liver Disease ) score of 10 or greater in patients undergoing hip or knee arthroplasty was associated with an increased likelihood of medical complications (odds ratio [OR], 3.16; 95% confidence interval [CI], 1.35–7.39), surgical complications (OR, 4.75; 95% CI, 1.45–15.56), and death (OR, 4.10; 95% CI, 1.42–11.86) compared to patients with cirrhosis who had a MELD score less than 10. They felt that alternatives to hip or knee arthroplasty should be considered in these patients. Note that the MELD score was revised in 2016 to incorporate serum sodium (MELD-Na), so that the scores diverge above 12.

Recommendations

Review with the anesthesia team about giving prophylaxis to patients at moderate risk for PONV. Ondansetron 4 mg, droperidol 1.25 mg, and dexamethasone 4 mg were shown to be equally effective in a study by Apfel et al., and each agent independently reduced PONV risk by approximately 25%. A single preoperative dose of dexamethasone 40 mg IV was shown to decrease PONV in a small study of THA patients without causing adverse outcomes, including wound complications, deep infections, or osteonecrosis in the contralateral hip. However, even with multiple drug treatment, more than 30% of high-risk patients had postoperative emetic symptoms in a large prospective observational study.
Minimize use of postoperative opioids to decrease baseline risk of PONV.
If the patient develops PONV despite prophylaxis, treatment should be with an antiemetic from a different pharmacologic class than the prophylactic drug(s). If no prophylaxis was given, the recommended treatment is a low-dose 5-HT ₃ antagonist such as ondansetron 1 mg. Aromatherapy with isopropyl alcohol is not effective in preventing PONV, but it may be helpful in treating PONV.
Although it has been reported that “little can be done preoperatively to reduce the risk for POI,” the medical team should strive to minimize both the surgical stress response and opioid medications as tolerated.
PC6 acupoint stimulation in patients at risk for PONV can provide relief comparable to antiemetics. The PC6 acupoint is located between the tendons of the palmaris longus and flexor carpi radialis muscles, 4 cm proximal to the wrist crease.
Peripherally acting μ-opioid receptor antagonists such as methylnaltrexone and alvimopan may be effective in treating POI and opioid-induced bowel dysfunction, but definitive conclusions are not possible because of study inconsistency and the relatively low quality of evidence.
Patients with chronic constipation should be on an appropriate bowel regimen and ideally should have a bowel movement prior to surgery given that anesthesia and opioid pain medications can worsen constipation.
Medications that increase the risk for acute colonic pseudo-obstruction should be carefully reviewed and decreased or stopped if possible.
Medical conditions associated with acute colonic pseudo-obstruction should be optimized.
Patients with advanced liver disease may require perioperative evaluation by a hepatologist.
Patients with advanced liver disease who require emergent surgery should be given vitamin K if they have an increased INR in case the increase is due to poor nutrition leading to vitamin K deficiency. They may need a platelet transfusion depending on the platelet count. Those with a history of significant alcohol consumption may be at risk of alcohol withdrawal and should be closely monitored perioperatively.

Genitourinary

Urinary complications following hip surgery include urinary retention and infection. Urinary retention itself can lead to UTI ; bladder catheterization, which is used to treat urinary retention, can also lead to infection, especially in the setting of prolonged catheterization. Each day of indwelling catheter use is associated with an approximately 3% to 7% risk of developing bacteriuria, which is usually asymptomatic. However, even catheter-associated urinary tract infections (CA-UTIs) are rarely symptomatic. According to the current guidelines from the Infectious Diseases Society of America, CA-UTI is defined in patients with indwelling urethral, indwelling suprapubic, or intermittent catheterization who have signs or symptoms compatible with UTI with no other identified source of infection along with greater than or equal to 1000 colony forming units (cfu)/mL of greater than or equal to 1 bacterial species in a single catheter urine specimen or in a midstream voided urine specimen from patients whose urethral, suprapubic, or condom catheter has been removed within the previous 48 hours. “Signs and symptoms compatible with CA-UTI include new onset or worsening of fever, rigors, altered mental status, malaise, or lethargy with no other identified cause; flank pain; costovertebral angle tenderness; acute hematuria; pelvic discomfort; and in those whose catheters have been removed, dysuria, urgent or frequent urination, or suprapubic pain or tenderness.”

Risk Factors.

Risk factors for UTI include female sex and poor preoperative medical condition. Risk factors for postoperative urinary retention include age greater than 50 years, male sex, preexisting obstructive urinary symptoms (benign prostatic hyperplasia [BPH]), previous pelvic surgery, neurologic disease (cerebral or spinal lesions, diabetic or alcoholic neuropathy), long duration surgery, spinal or epidural anesthesia, postoperative sedative medications such as midazolam, and continuous epidural analgesia.

Recommendations

Infectious Diseases Society of America guidelines state that pyuria accompanying asymptomatic bacteriuria (≥ 100,000 cfu/mL [diagnosis requires two consecutive voided specimens for women, one for men] or ≥ 100 cfu/mL of a single bacterial species in a catheterized specimen for women or men) is not an indication for antimicrobial treatment except for pregnant women. However, antimicrobial treatment “may be considered” for asymptomatic women with catheter-acquired bacteriuria that persists 48 hours after indwelling catheter removal. These guidelines do not discuss patients with prosthetic implants.
Likewise, Infectious Diseases Society of America guidelines state that pyuria in the catheterized patient is not diagnostic of catheter-associated bacteriuria or CA-UTI, and pyuria accompanying catheter-associated asymptomatic bacteriuria should not be interpreted as an indication for antimicrobial treatment. These guidelines also do not discuss patients with prosthetic implants.
Urinary catheters, if required, should be used only for a short duration (≤ 24 hours). In-and-out catheterization is preferred over indwelling bladder catheters.
Routine placement of indwelling bladder catheters may not be necessary for patients undergoing total hip replacement under spinal anesthesia.
Patients with an indwelling bladder catheter who have a CA-UTI should be treated with antibiotics for 7 days if they have prompt resolution of symptoms and for 10 to 14 days if they have a delayed response, regardless of whether they remain catheterized. A 5-day regimen of levofloxacin may be considered in patients with CA-UTI who are not severely ill, and a 3-day antimicrobial regimen may be considered for women less than or equal to 65 years of age who develop CA-UTI without upper urinary tract symptoms after an indwelling catheter has been removed.
A meta-analysis indicated overall benefit of antibiotic prophylaxis at the time of removal of a urinary catheter to prevent subsequent UTIs, with a number needed to treat of 17 to prevent one symptomatic UTI. However, it is not known how prophylaxis may affect antimicrobial resistance.
Of concern in orthopedic surgical patients is whether UTI or asymptomatic bacteriuria will cause a prosthetic joint infection. As mentioned earlier, recent evidence would favor evaluating only symptomatic patients and treating UTIs instead of obtaining routine urine studies in asymptomatic patients prior to joint arthroplasty, as they would not treat asymptomatic bacteriuria.

Renal

Postoperative acute kidney injury (AKI) may occur, increasing mortality and length of stay. AKI is defined as an increase in serum creatinine by greater than or equal to 0.3 mg/dL within 48 hours; increase in serum creatinine to greater than or equal to 1.5 times baseline, which is known or presumed to have occurred within the prior 7 days; or urine volume less than 0.5 mL/kg/h for 6 hours. Note that decreased urine output is common in the first 12 to 24 hours after surgery and does not necessarily imply kidney injury but typically reflects an increase in antidiuretic hormone due to the surgical stress response.

Risk Factors.

In general, the risk of developing AKI is increased by exposure to factors that cause AKI or the presence of factors that enhance susceptibility to AKI. Exposures include sepsis, critical illness, circulatory shock, burns, trauma, major noncardiac surgery, nephrotoxic drugs, and radiocontrast agents (although recent retrospective studies have shown that IV contrast media for computed tomography [CT] imaging does not increase the risk of AKI) ). Susceptibilities include dehydration or volume depletion, advanced age, female gender, black race, chronic kidney disease, diabetes, cancer, anemia, and other chronic diseases such as heart, lung, and liver disease. A Mayo Clinic study of over 10,000 hip surgeries in a predominately white population found that chronic kidney disease, heart failure, diabetes mellitus, hypertension, male sex, and older age are independent risk factors for AKI ; an online calculator based on this study is available at https://qxmd.com/calculate/calculator_455/mayo-aki-risk-after-primary-total-hip-arthroplasty . These researchers found that prerenal etiologies (including hypotension) and acute tubular necrosis were the most common causes of postoperative AKI. Measures to help prevent AKI include optimizing hemodynamics and correcting any volume deficits.

Recommendations

Strive to maintain euvolemia and avoid hypotension/decreased kidney perfusion pressure.
Hold diuretics the morning of surgery.
In general, we hold ACE inhibitors and ARBs the morning of surgery.
It may be necessary to provide intravenous (IV) hydration postoperatively until patients have improved oral intake (typically, at least 500 cc).

Psychiatric

Delirium after hip fracture is the most common psychiatric complication and is associated with prolonged hospital stay, higher cost, poor outcome, and the need for nursing home placement. Delirium typically occurs when predisposing factors coincide with precipitating factors. Other psychiatric complications following orthopedic surgery include unexpected chronic postoperative pain and alcohol withdrawal.

Risk Factors.

Underlying cognitive impairment is the most consistently significant preoperative risk factor for postoperative delirium after hip fracture surgery and may not have been previously evident until the episode of delirium. Similarly, in a study of hip surgery patients, Slor et al. found that preexisting cognitive decline was the principal predictor of delirium duration. Other risk factors include older age, lower education level, sensory impairment, decreased functional status, comorbid medical conditions, malnutrition, depression, general anesthesia, and a history of delirium. Precipitating factors include hemodynamic instability, hypoxemia, electrolyte disturbance, transfusion requirement, sleep deprivation, urinary catheterization, immobility, poorly controlled pain, and polypharmacy, especially with opioid medications and/or benzodiazepines as well as with anticholinergics such as diphenhydramine.

Patients with preoperative anxiety and depression may be more likely to have persistent long-term discomfort after THA. Alcohol abuse is an important risk factor even if there is no overt alcohol-related organ dysfunction, as it can lead to immunosuppression, subclinical cardiac dysfunction, and an amplified hormonal response to surgery.

Recommendations

Patients at high risk for delirium (including those with underlying cognitive impairment/dementia and elderly hip fracture patients) should have a preoperative baseline mental status assessment such as the Folstein Mini-Mental Status Examination or the clock drawing test.
Diagnose delirium using the Confusion Assessment Method (see later “ Postoperative Medical Complications ” section), noting that many patients may have the hypoactive form rather than the hyperactive/agitated form, either of which can have hallucinations and delusions.
Hospitals should implement multicomponent nonpharmacologic intervention programs delivered by an interdisciplinary team for the entire hospitalization in at-risk older adults undergoing surgery to help prevent delirium. Nonpharmacologic measures include cognitive reorientation, sleep enhancement (nonpharmacologic sleep protocol and sleep hygiene), early mobility and/or physical rehabilitation, adaptations for visual and hearing impairment, adequate nutrition and fluids, pain management, appropriate medication use, adequate oxygenation, and prevention of constipation.
Physical restraints to manage behavioral symptoms of hospitalized older adults with delirium should be avoided if at all possible.
Geriatric consultation has been shown to reduce delirium incidence and should be considered for patients at high risk for delirium.
Providers should strive to balance pain control and opioid use. Consider opioid-sparing analgesia as tolerated, including ice, acetaminophen, and regional nerve blocks.
Evidence is mixed regarding whether melatonin and the melatonin agonist ramelteon help prevent delirium, with a meta-analysis of three pooled studies showing no benefit. However, we question whether melatonin and ramelteon should be assumed to be equivalent, as in this analysis. The included ramelteon study, which was a small study of hospitalized patients who were admitted for serious medical conditions, showed a significant decrease in the incidence of delirium: 32% of control patients had delirium while only 3% of treated patients had delirium. These treated patients were given a dose of ramelteon 8 mg nightly for 7 nights, including into the postdischarge period. In a separate study of melatonin (not included in the aforementioned meta-analysis) given to a group of hip arthroplasty surgery patients who had spinal anesthesia, 32.65% of the control patients developed delirium compared with 9.43% of the melatonin patients. Two meta-analyses of antipsychotics showed no clear benefit for delirium prevention. However, a subgroup analysis showed that patients treated with an atypical antipsychotic (olanzapine) compared with placebo had a lower incidence of delirium (relative risk, 0.36; 95% CI, 0.24–0.52). Another systematic review and meta-analysis noted that second-generation antipsychotics such as olanzapine and risperidone appear to be more beneficial than placebo for decreasing the incidence of delirium. Among these patients who did develop delirium, the severity of delirium was not reduced in those who received prophylactic antipsychotics.
Patients with preoperative anxiety and depression may need appropriate treatment prior to surgery to help decrease the likelihood of persistent pain following surgery.
Patients with a history of alcohol abuse should be monitored for withdrawal and should have electrolytes, including potassium and magnesium, checked perioperatively and replaced as needed. They should also be given thiamine 100 mg daily for 5 days (one intravenous or intramuscular dose and four oral doses) along with a daily multivitamin.
It is important to note that melatonin, ramelteon, olanzapine, and risperidone are not approved by the US Food and Drug Administration (FDA) for the prevention of delirium.

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