Medical Management of the Patient With Hip Fracture

The outcome of a patient with a hip fracture is only partially related to the successful surgical management of the fracture. Many elderly patients have multiple, significant concomitant illnesses. These comorbidities, as well as perioperative complications, significantly impact the patient's ultimate outcome. This chapter reviews factors affecting the outcome after a hip fracture; management of common coexisting medical conditions; postoperative complications; and interventions to optimize medical, functional, and cognitive outcomes.

Outcome Variables

Mortality

Although the mortality for elderly patients who have suffered a hip fracture continues to be substantial, the age- and risk-adjusted mortality in the United States for these fractures has declined in recent decades. Adjusted 1-year mortality for women decreased from 24% in 1986 to 21.9% in 2004. The 1-year mortality for males decreased from 40.6% to 32.5%. The decrease in mortality, however, was entirely in the first 10 years of the study from 1986 to 1995. After 1998, however, there was very little change in mortality for either males or females.

A systemic review and meta-analysis of preoperative predictors for mortality after hip fractures found strong evidence for the following mortality predictors: advanced age, male sex, nursing home residency, poor preoperative walking capacity, poor activities of daily living, higher American Society of Anesthesiologists (ASA) grading, poor mental state, multiple comorbidities, dementia or cognitive impairment, diabetes, cancer, and cardiac disease. The impact of residency in a nursing home on mortality is substantial. A study of 195 residents of a teaching nursing home in Boston found that 70% of these residents with hip fractures died within 1.4 years. Several studies have specifically evaluated the impact of malnutrition on 12-month mortality after these fractures. Malnutrition was one of the most significant predictors of mortality for these patients.

A group of orthopaedic surgeons in Nottingham, England, developed a preoperative scoring system to predict 30-day mortality in patients after a hip fracture. The variables felt to be the most important predictors of 30-day mortality were as follows: age over 85, male sex, the number of comorbidities, a mini-mental status test score of 6 or less out of 10, lower hemoglobin concentration at admission, living in an institution, and the presence of malignant disease. A subsequent study found that this “Nottingham scale” was also predictive of 1-year mortality.

Recovery of Function

Recovery of mobility is rated by patients with hip fractures as the most important outcome from their hip fracture repair. Dyer and colleagues performed a critical review of disability outcomes after hip fractures in 2016. They reported that 40% to 60% of surviving patients regained their prefracture level of mobility within 1 year. Recovery of mobility is lower for those living in residential care than for those living in the community. Approximately 34% to 59% of patients regain their prefracture level of function in basic activities of daily living (ADLs) by 3 months. This proportion rises to from 42% to 71% by 6 months. Although approximately 60% to 70% of patients are independent in basic ADLs prefracture, this decreases to from 40% to 60% postfracture. Approximately 20% to 65% of patients who are independent in performing self-care activities before the fracture require assistance with these tasks 1 year later.

Half or fewer of patients experiencing hip fracture regain their prefracture level of function in instrumental activities of daily living (IADLs). Most patients who recover function do so within the first 6 months after fracture.

Physical function before the fracture, measured as previous walking ability, hand grip strength, or mobility level of walking outdoors and indoors, has been found in a number of studies to be the most consistent predictor of good recovery of function after a hip fracture.

Cognitive status is rarely thoroughly evaluated for patients with hip fractures. Jones et al. performed cognitive status examinations on all patients 3 to 5 days after surgery for hip fractures. After adjusting for age, sex, proxy respondent, and fracture type, participants with impaired cognition recovered more slowly, never attaining comparable levels with those without cognitive impairment. Although cognitive status is an important predictor of poor functional outcomes, it is not as important as prefracture functional state. Other predictors of poor functional recovery are advanced age, male sex, pressure sores, and postoperative delirium.

Medical Complications

Medical complications are common in patients with hip fractures. Approximately 8% of patients have cardiac complications, and 4% have pulmonary complications. Serious pulmonary complications, however, are as common (2.6%) as serious cardiac complications (2.0%). In one study, gastrointestinal bleeding was seen in 2% of patients, and venous thromboembolism, transient ischemic attacks, cerebrovascular accidents, and hypotension were seen in approximately 1% of patients. A large Danish study found that 12.7% of patients developed some degree of acute renal failure postoperatively. Renal failure was associated with a higher mortality. Moderate to severe aortic stenosis clearly increases the complication rate and mortality. In a study at Mount Sinai Hospital in New York, patients with aortic stenosis and hip fractures had twice the rate of perioperative complications; 30-day mortality was 14.7% for these patients versus 4.2% for patients without aortic stenosis. One-year mortality was 46.8% versus 14% for patients without this condition.

Key Points: Outcome Variables

The mortality of hip fractures is high (22% to 32%), with no improvement noted since 1998.
There are multiple risk factors and predictors for mortality, including advanced age, male sex, nursing home residency, poor preoperative walking capacity, poor ADLs, higher ASA grading, poor mental state, multiple comorbidities, dementia or cognitive impairment, diabetes, cancer, and cardiac disease.
Predictors of poor functional recovery are impaired cognitive status, impaired preoperative functional status, advanced age, male sex, pressure sores, and postoperative delirium.

Preoperative Assessment

A preoperative examination and assessment are required to determine the patient's baseline medical condition, identify decompensated or previously unrecognized conditions, and assess the perioperative risk for a postoperative complication. The vast majority of patients with hip fractures are above the age of 70. There are a number of physiologic changes that occur with aging. The older individual has decreased physiologic reserve. There is a predictable decline with age in pulmonary vital capacity, cardiac output, renal blood flow, glomerular filtration rate, and neuromuscular reaction time. There is also a marked increase in the prevalence of diseases with aging. Of patients above the age of 70, 90% have at least one comorbid condition. One-third of older patients have at least three or more comorbid conditions. It is the presence of these diseases, more than the changes with age, that increase the risk of surgery for older individuals. The older individual has a decreased ability to react to stress. This diminished reserve of the older patient may be less apparent on history and physical examination because of decreased activity due to joint disease, vascular insufficiency, or other limiting factors.

This section reviews the process of identifying and optimizing patients’ clinical conditions, with the goal of reducing the risk of perioperative complications with hip fracture surgery.

Cardiovascular Assessment

A number of studies have evaluated factors that increase the risk for cardiovascular events in patients undergoing noncardiac surgery. The stress of surgery causes increased cardiac output and increased myocardial oxygen demand and may induce cardiac ischemia. In addition, anesthetic agents can depress the myocardium, cause peripheral vasodilatation, and can induce arrhythmias.

The American Heart Association and the American College of Cardiology (ACC/AHA) released their most recent guidelines on perioperative cardiovascular evaluation and risk stratification in 2014. Following these guidelines, patients presenting with a hip fracture may be rapidly risk stratified and medically optimized, with the goal of operative hip fracture repair within 48 hours to reduce postoperative morbidity and mortality and improve postfracture functional status.

The only patients who absolutely require a delay in the operative procedure are those with an unstable cardiac presentation such as decompensated heart failure, unstable arrhythmia, unstable angina, or an acute coronary syndrome. These patients require urgent cardiology evaluation and stabilization before surgery. All other patients should be risk stratified for their estimated risk of major adverse cardiac events associated with the planned surgical procedure. The goal of risk stratification is to provide the patient, family, surgeon, and anesthesiologist with information to make informed decisions. Because hip fracture surgery is essential for pain management and mobility, it is very rare that the risks of surgery would be assessed to outweigh the benefits. Even patients with end-stage malignancy or dementia require surgical stabilization to reduce the pain associated with rolling onto a bedpan or bathing in bed. In some cases, the risk-stratification process provides an opportunity to discuss goals of care and consideration of hospice care, if appropriate.

The Revised Cardiac Risk Index (RCRI) or the National Surgical Quality Improvement Project (NSQIP) risk calculator may be used ( http://www.riskcalculator.facs.org ) for cardiac risk stratification. Patients with a low (<1%) risk of major adverse cardiac events may proceed to surgery without further risk assessment. The RCRI scoring system is outlined in Tables 53.1 and 53.2 .

Table 53.1

Revised Cardiac Risk Index (RCRI)

Clinical Variable	Points
High-risk surgery	1
History of ischemic heart disease	1
History of congestive heart failure	1
History of cerebrovascular disease	1
Insulin treatment for diabetes mellitus	1
Preoperative serum creatinine >2.0 mg/dL	1

Table 53.2

Interpretation of Revised Cardiac Risk Index (RCRI) Risk Score

Risk Class	Points	Risk of Major Adverse Cardiac Events (%)
Low	0	0.4
Elevated	1	0.9
Elevated	2	7.0
Elevated	3+	11.0

The ACC/AHA guidelines recommend that patients with an elevated risk of major adverse cardiac events (>1%) should be further risk stratified by functional status. Patients with moderate, good, or excellent functional capacity (≥4 metabolic equivalents or METs) may proceed to surgery without further evaluation. Four METs is the equivalent of walking up a flight of stairs or walking one city block on level ground.

Many patients with hip fractures will have elevated cardiac risk with an unknown or limited functional status. The ACC/AHA guidelines recommend that in these cases, the medical team and the patient should together determine whether further testing would impact clinical decision making. In the specific case of patients with hip fractures, the benefit of prompt surgical repair outweighs any benefit derived from further risk stratification. In one study of 235 consecutive patients treated for hip fracture, 15% had cardiac testing as recommended by the medical consultants. Cardiac testing in this study included dobutamine echocardiography, two-dimensional echocardiography, stress testing, and cardiac catheterization. In 48% of cases, cardiac testing prompted no new medical recommendations, and in 52% of cases, new medical recommendations were made for management of previously known disease. Cardiac testing resulted in a significant delay to surgery (3.3 days in patients undergoing testing vs. 1.9 days in patients with no additional cardiac testing) and excessive costs. In patients with hip fracture and stable cardiac disease with no evidence of decompensated heart failure, unstable arrhythmia, or acute coronary syndrome, no additional cardiac testing has been demonstrated to improve outcomes.

The question of how to best ameliorate the risk of major adverse cardiac events in patients with elevated risk is an area of ongoing study. After years of controversy, the current evidence supports the uninterrupted use of β-blockers to reduce perioperative cardiac events in patients on β-blockers before presentation for surgery. However, the preoperative de novo administration of β-blockers is no longer recommended to reduce surgical death. Patients not previously treated with β-blockers should no longer be treated with an intravenous or oral “load” of β-blockers before surgery.

Congestive Heart Failure

Congestive heart failure is a major determinant of postoperative complications. Patients with symptomatic congestive heart failure, or findings on examination of elevated jugular venous distension, pulmonary crackles, or an S ₃ gallop, have an increased risk of pulmonary edema and cardiac death. As stated previously, patients with decompensated heart failure require a delay in surgery for further cardiac evaluation and stabilization.

The etiology of the patient's heart failure should be reviewed and the patient's volume status optimized before surgery. Diuretics must be used with caution because over-diuresis will lead to intravascular volume depletion and intraoperative hypotension and may lead to hypokalemia, with a resultant increased risk for dysrhythmias. The introduction of digitalis preparations in the perioperative stage should be avoided because it increases the risk of bradyarrythmias.

Routine preoperative transthoracic echocardiography does not add to the clinical evaluation and does not have a role in the standard preoperative assessment. In one study, the information obtained by the transthoracic echocardiogram did not improve the prognostic information already obtained with the known risk factors from the preoperative evaluation.

Valvular Disease

Significant aortic stenosis increases perioperative cardiac risk. Nonetheless, patients with known aortic stenosis or a history and examination consistent with significant aortic stenosis can be operated upon safely, provided they have not had congestive heart failure. Patients with severe aortic stenosis (aortic valve area index ≤0.5 cm ² /m ² or mean aortic valve gradient ≥50 mm Hg) often develop intraoperative hypotension and require an intraarterial catheter, and possibly pulmonary artery catheterization, for prompt recognition and management. Patients with known mitral regurgitation or aortic insufficiency who are asymptomatic, with no evidence of decompensation, require no further evaluation.

After a careful assessment of the patient's volume status, maintenance diuretics and routine cardiac medications may be continued. The possible exception may be angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs). Data on the benefits and potential risks of ACE inhibitor use perioperatively are limited to observational studies. One study showed that preoperative ACE inhibitor use resulted in more frequent transient intraoperative hypotension but no difference in outcomes. A meta-analysis of available trials showed hypotension in 50% of patients taking ACE inhibitors or ARBs on the day of surgery. There was no impact on outcomes of death, myocardial infarction (MI), stroke, or kidney failure. Based on these studies, many experts recommend that ACE inhibitors and ARBs be held on the morning of surgery.

Hypertension

Hypertension is a common problem in the elderly. Patients with well-controlled blood pressure have wider fluctuations in both systolic and diastolic pressures intraoperatively but do not experience more cardiac complications because of the hypertension. Antihypertensive therapy should be continued orally or intravenously. Patients whose blood pressure is not well controlled (those with a diastolic blood pressure greater than 110 mm Hg) may be at increased risk for intra- and postoperative cardiac complications. Treatment with intravenous antihypertensive medications is warranted for blood pressure control before surgery. Labetalol, metoprolol, and hydralazine are all effective intravenous perioperative antihypertensive agents.

Atrial Fibrillation

Atrial fibrillation is common in elderly patients presenting with hip fractures. Patients should continue their prescribed home rate-control therapy, such as calcium channel blockers, β-blockers, or digoxin. In addition, patients may require intravenous doses of metoprolol or diltiazem to achieve a perioperative target heart rate of less than 110 beats per minute.

Anticoagulation

Many patients will present to the emergency department on full therapeutic anticoagulation. Patients are most commonly on anticoagulation for stroke prevention in atrial fibrillation, prevention of thrombosis with mechanical valves, and long-term treatment of venous thromboembolic disease. Oral anticoagulants include vitamin K antagonist (warfarin), direct thrombin inhibitor (dabigatran), and factor Xa inhibitors (rivaroxaban and apixaban).

The indication for the anticoagulation and the surgical risk of bleeding are the most important determinants in managing blood thinners perioperatively. Patients with a low risk of thrombosis with perioperative interruption of anticoagulation may have anticoagulants withheld temporarily. Patients with moderate to high risk of thrombosis require “bridging” anticoagulation with intravenous unfractionated heparin administered until 6 hours before surgery and resumed 6 hours after surgery.

Table 53.3 illustrates medical conditions classified as low, moderate, and high risk for thrombosis.

Table 53.3

Risk of Thrombosis With Anticoagulation Interruption

Low Risk (<5%/year)	Moderate Risk (5–10%/year)	High Risk (>10%/year)
AF with CHA ₂ DS ₂ -VASc score <5 Bioprosthetic valve PE/DVT >3 months ago	AF with CHA ₂ DS ₂ -VASc score 5–7 AF with structural heart disease Bioprosthetic valve with structural heart disease Mechanical aortic valve PE/DVT 1–3 months ago	AF with CHA ₂ DS ₂ -VASc score 8–9 AF with any mechanical valve Mechanical mitral valve Multiple valve replacements PE/DVT <1 month ago

AF, Atrial fibrillation; CHA ₂ DS ₂ -VASc, atrial fibrillation risk-scoring calculator (available at https://www.chadsvasc.org ); DVT, deep vein thrombosis; PE, pulmonary embolism.

In general, patients undergoing orthopaedic surgery should have an international normalized ratio (INR) of less than 1.5 if taking warfarin. Patients taking apixaban, rivaroxaban, or dabigatran should have hip fracture surgery delayed until 48 hours after their last administered dose. Patients on novel oral anticoagulants with renal compromise may require a longer delay to surgery.

Preoperative Antiplatelet Therapy

Antiplatelet therapy is most commonly used in patients with ischemic heart disease, peripheral vascular disease, cerebrovascular disease, and coronary stents. Aspirin is known to increase the risk for blood loss and transfusions in hip fractures and hip fracture surgery. A meta-analysis of 14 studies in patients undergoing early hip fracture surgery while on clopidogrel (Plavix) looked at perioperative bleeding. The meta-analysis showed no significant difference in postoperative hemoglobin, drop in hemoglobin from pre- to postoperatively or total units of blood transfused in patients on clopidogrel compared with patients not on clopidogrel. Aspirin was used in both the clopidogrel and nonclopidogrel groups. This study suggests that the addition of clopidogrel to aspirin may not have a significant impact on perioperative blood loss.

Patients with coronary artery stents requiring antiplatelet therapy present a challenge to the surgeon. Depending on the type of stent, bare metal or drug eluting, and the time since stent placement, the patient will be on at least one antiplatelet medication, possibly both. Discontinuing antiplatelet therapy and delaying surgery until new platelets are produced is not an option. Discontinuing all antiplatelet therapy is unwise.

The risk of stent thrombosis in the perioperative period for bare metal and drug-eluting stents is highest within 4 to 6 weeks of initial stent placement. The most recent ACC/AHA guidelines recommend that the decision to continue aspirin or dual-antiplatelet therapy perioperatively within this early period after stent implantation must be individualized, accounting for the risk of stent thrombosis and the risk of surgical bleeding. In the case of hip fracture surgery, the risk of cardiac complication in discontinuing antiplatelet therapy soon after stent placement will always outweigh the surgical bleeding risk.

Even beyond 4 to 6 weeks after stent implantation, the risk of complications remains elevated. McFadden et al. reported four patients who had their antiplatelet therapy discontinued between 335 and 445 days after stent placement. All four suffered stent thrombosis, one only 4 days after discontinuing both aspirin and clopidogrel. Another patient, on aspirin only, suffered stent thrombosis 5 days after discontinuing the aspirin.

Newer-generation drug-eluting stents (zotarolimus- and everolimus-eluting stents) are associated with approximately half the risk of stent thrombosis as compared with first-generation drug-eluting stents (sirolimus- and paclitaxel-eluting stents). The type and timing of stent placement should therefore be accounted for when making preoperative antiplatelet therapy recommendations.

Pulmonary Assessment

Although cardiac complications are more common than pulmonary complications after a hip fracture, serious pulmonary complications occur at least as often as serious cardiac complications. Risk factors for postoperative pulmonary complications (PPCs) have been well defined. Elderly patients have an increased risk of PPCs even after adjusting for the higher prevalence of comorbid conditions. Tobacco use—even in the absence of chronic obstructive pulmonary disease (COPD)—increases risk. Higher-acuity patients have a higher risk of postoperative pulmonary complications. American Society of Anesthesiologists (ASA) class II patients have a 5.2% risk of PPCs, whereas ASA III and ASA IV patients have a risk of 11.4% and 10.9%, respectively.

Increased severity of COPD confers a greater risk of PPCs. Major PPCs include pneumonia, respiratory failure, inability to extubate within 48 hours of surgery, or need for reintubation. Patients with severe COPD have a 23% risk of a major PPC. Patients with mild to moderate COPD have a 10% risk of a major PPC. Smokers with normal spirometry have a 4% risk of PPC. New York Heart Association (NYHA) class II or greater pulmonary hypertension, obstructive sleep apnea (OSA), and nutritional status all confer an increased risk of PPCs. Well-controlled asthma is not a significant risk factor for PPCs.

There are no studies that provide evidence that preoperative chest radiography effectively risk stratifies patients with lung disease. Routine use of pulmonary function tests and arterial blood gas have no role in preoperative pulmonary risk stratification. Pulmonary risk indices have been published, and the factors that most strongly correlate with increased risk of postoperative respiratory failure and postoperative pneumonia are surgery-specific factors and patient comorbidities that are not easily modifiable before hip fracture surgery.

The challenge for the medical consultant is to identify modifiable risk factors for postoperative pulmonary complications and optimize these risks before, during, and after surgery. Before surgery, obstructive lung disease should be optimized with bronchodilators, steroids, and antibiotics, as needed. Perioperative blood products are best used sparingly. In one study, allogenic blood transfusion resulted in an almost threefold increased risk of postoperative pneumonia. A higher number of red blood cell concentrate units transfused was correlated with an increase in pneumonia risk. The same study demonstrated that a longer preoperative hospital stay increased the risk of postoperative pneumonia.

Intraoperatively, epidural anesthesia may be associated with lower rates of postoperative pneumonia when compared with general anesthesia. Similarly, short-acting neuromuscular blockers result in lower rates of postoperative pneumonia (atracurium is therefore preferred over pancuronium).

Postoperatively, patients are three times more likely to develop a PPC for each postoperative day they do not mobilize away from the bed after surgery. Measures to prevent postoperative aspiration pneumonia in hip fracture patients include getting patients up and out of bed for meals and avoiding unnecessary use of stress ulcer prophylaxis. Decreased intragastric acidity creates a favorable environment for colonization of the stomach by pathogens and increases the risk of pneumonia with an aspiration event.

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