Pain Management in the Head and Neck Patient

Epidemiology

More than 50 million surgical procedures are performed in the United States annually, 5.2 million of which are related to the otolaryngology specialty. The growth of ambulatory surgery is one of the most significant recent changes in surgical practice, with 92% of otolaryngologic procedures currently done in an ambulatory setting. Planning postoperative pain management is especially important for outpatient ambulatory surgeries because the opportunities for patient evaluation and adjustment of pain therapies will be fewer than with inpatient postoperative care.

Patient Satisfaction

Patient satisfaction is an integral part of pay-for-performance programs, and pain management is an important determinant of patient satisfaction. Inadequate postoperative pain relief reduces patient comfort, decreases recovery speed, lengthens hospital stay, increases morbidity and mortality, and decreases quality of life. The Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) is a standardized instrument and data collection methodology used to measure and publicly report patients’ experiences of hospital care. The Centers for Medicare and Medicaid Services have mandated the use and public reporting of HCAHPS scores. These scores also affect reimbursement, and acute care hospitals had 2% of their Medicare diagnosis-related group reimbursements subject to a favorable score for the 2017 fiscal year.

Factors that contribute to patient satisfaction with postoperative pain management include how quickly the medical staff acts on complaints of pain, the frequency of uncontrolled pain episodes, and the adequacy of pain treatments. Patient dissatisfaction is increased if a request for analgesics is followed by inadequate pain treatment, but no direct correlation between pain intensity and patient satisfaction has been found. In fact, patient satisfaction has been found to be more strongly correlated with the perception that caregivers did everything they could to control pain than with the degree of pain control actually experienced. The odds of a patient being satisfied were 4.86 times greater if pain was controlled but almost 10 times greater if patients rated staff performance highly. Patients who have the opportunity for self-administration of analgesics, as with patient controlled analgesia (PCA), report a feeling of autonomy and security and improved satisfaction compared with those treated with as-needed nurse-administered analgesics. Health care provider knowledge regarding dosing and duration of action of opioids also impacts the quality of postoperative pain management. Therefore patients treated with standardized pain management by an acute pain service are more likely to report being satisfied with their postoperative pain management.

When evaluating the desirability of postoperative pain management outcomes, patients place similar importance on analgesic efficacy compared with the type and severity of analgesic adverse effects experienced. Common opioid adverse effects include sedation, respiratory depression, gastrointestinal dysfunction (nausea, vomiting, constipation, ileus), mental confusion, dizziness, mood change, nightmares, hallucinations, urinary hesitancy, and sleep disorders. In addition, when comparing intravenous (IV) PCA in the hospital to oral opioids in the hospital or oral opioids at home, the site and mode of delivery for opioid administration appear to be of less importance to patients than pain relief and side effects. Patient variability is high regarding willingness to trade pain efficacy for different or milder side effects. These factors may assist with individualizing pain treatments to match the clinical setting and the patient's needs, thereby improving compliance and patient satisfaction.

Preemptive Versus Preventive Analgesia

Preemptive analgesia is pain treatment given before tissue injury, as for surgery, to prevent the establishment of altered central processing of afferent input from sites of injury and thereby prevent the development of pain hypersensitivity. It was initially hypothesized that a preemptive treatment would prevent central hypersensitivity, decrease the incidence of hyperalgesia, and reduce the magnitude and duration of postoperative pain. Preventive analgesia , on the other hand, does not require that an intervention be initiated before surgery; the timing may be during the procedure or even after the surgery. In contrast to timing, the concept of preventive analgesia is focused on the intensity and duration of the analgesic intervention.

Randomized controlled trials of preemptive analgesia in acute postoperative pain have had mixed results and have been the subject of extensive debate. One setting in which application of analgesic therapies has been shown to preemptively reduce postoperative pain is pediatric tonsillectomy. Preincision infiltration of local anesthesia and general anesthesia for pediatric tonsillectomy has been shown to reduce posttonsillectomy pain specifically, and it provides a more rapid return to activity compared with general anesthesia alone. Pharmacologic agents, such as nonsteroidal antiinflammatory drugs (NSAIDs), opioids, N -methyl- d -aspartate (NMDA) antagonists, anticonvulsants (e.g., gabapentin), and α ₂ -adrenergic receptor antagonists, are effective at synergistically decreasing postoperative pain, but the preemptive administration of these pharmacologic agents does not yield increased analgesic benefit when compared with postincision administration. Because pain management therapies are unable to preempt the development of postoperative pain in most surgical settings, planning to optimally control perioperative pain should be an integral component of all surgical care plans.

Perioperative Opioids and Their Role in the Opioid Epidemic

The rate of opioid overdoses in the United States has increased considerably, nearly tripling in number since 1999. During that same period, opioid prescriptions have quadrupled, rising in parallel with the number of opioid overdoses. Postoperative opioid prescribing patterns and new persistent use have been shown to play a significant part in the current opioid epidemic, with approximately 6% of adults continuing to receive prescription opioids 3 to 6 months after surgery (or approximately 3 million opioid-naïve patients per year). Postoperative prescribing patterns of opioids have trended towards providing patients with increased amounts of opioids, often in anticipation of pain and to increase patient satisfaction. Because of this, increased unused opioids are left in circulation and are often not securely stored, and therefore may be accessible to unintended individuals for misuse, abuse, or diversion. In the 2016 results of the National Survey on Drug Use and Health, 53% of prescription pain relievers misused by individuals aged 12 or older were either given by, bought from, or taken from a friend or relative who had a valid prescription. Because of this, recent studies in head and neck surgery have focused on determining the analgesic requirements needed after specific procedures to reduce the amount of unused opioids. For example, Scalfani et al. determined that pain after septoplasty and rhinoplasty was generally mild and postoperative opioid requirements were quite low. They stated that reducing opioid prescribing to as low as 10 to 11 hydrocodone-acetaminophen (APAP) 5/325 tablets would provide sufficient analgesic needs to 90% of patients without adverse impact and simultaneously reduce the availability of unused opioids for potential misuse or diversion.

Long-term use of opioids in patients may be triggered by opioids prescribed perioperatively. Even opioids prescribed for outpatient or short-stay surgeries may increase the risk of persistent opioid use by 44%. Martin et al. found that more than 60% of people receiving 90 days of continuous opioid therapy remain on opioids years later. Because of the possible transition from acute to long-term opioid use after surgery, measures to curb the amount and duration of postoperative opioids are increasingly being investigated.

Multimodal Analgesia

Multimodal analgesia is the combination of different analgesic regimens, either medications or other interventions, that act by different mechanisms to provide additive or synergistic pain relief and reduce adverse effects compared with the use of individual analgesics alone. Although opioids continue to play an important role in the management of severe acute postoperative pain, nonopioid analgesics are increasingly used to lower anesthetic and analgesic requirements, reduce postoperative pain, reduce opioid doses and opioid-related side effects, and potentially shorten hospital stays. Implementation of multimodal analgesia in outpatient thyroid and parathyroid surgery was associated with a significant decline in the prescription of postoperative opioid analgesics. As the number of minimally invasive surgical procedures increases, nonopioid analgesics are routinely used as preventive analgesics, with rescue doses of opioid given as needed. Both opioid and nonopioid adjuvant analgesics are reviewed later in this chapter with regard to their potential roles in postoperative pain management.

Enhanced Recovery After Surgery

There has been a recent paradigm shift toward enhanced recovery after surgery (ERAS) protocols to reduce morbidity, decrease practice variability, and shorten length of stay by mitigating the stress response after surgery. Initially introduced in the late 1990s/early 2000s by Henrik Kehlet for patients undergoing colorectal surgery, evaluation of ERAS protocols has shown significant patient improvements in function after surgery. In addition to multimodal pain management, ERAS protocols provide guidance on preadmission education, perioperative nutritional care, thromboembolism prophylaxis, antibiotic prophylaxis, preanesthetic medications, standard anesthetic protocols, prevention of hypothermia, postoperative mobilization, postoperative wound care, urinary catheterization, and postoperative pulmonary physical therapy. This concept has been applied to the broad spectrum of surgical specialties, including otolaryngology, creating a revolution in the way perioperative care is provided and measured.

Patient Controlled Analgesia

Parenteral administration of opioid analgesics via IV PCA may be used in the immediate postoperative setting. PCA benefits potentially include improved pain control and patient satisfaction, as well as improved nursing satisfaction and efficiency. The degree of pain relief achievable and the amount of analgesic used with PCA, relative to conventional methods of administration (intramuscular, subcutaneous, oral, continuous, IV intermittent), is variable. It is reasonable to assume that provision of analgesics in a dose and interval tailored to an individual's specific needs would result in good outcomes regardless of the specific technique used. Using PCA opioids to control pain, as with any route or method of opioid administration, may be complicated by adverse effects; however, PCA use is not associated with increased risk of significant adverse events. The choice of opioid should be made based on the patient's clinical history and drug availability. It should be noted that after IV administration, morphine slowly crosses the blood-brain barrier which may contribute to the development of delayed onset of analgesic effects and respiratory depressant effects. This necessitates added caution when morphine (compared with hydromorphone or fentanyl) is used for PCA, particularly in the setting of renal insufficiency, which prolongs morphine elimination.

To use PCA opioid for pain control, choices must be made regarding selection of drug, demand (bolus) dose, time interval (frequency), whether to use a basal (continuous) infusion, and the maximum dose allowed. Table 14.1 lists equianalgesic doses of commonly used opioid analgesics. Typical starting doses for IV PCA would be 1 to 2 mg morphine or 0.2 to 0.4 mg hydromorphone, with a 10-minute lockout interval between doses and no basal infusion. A lockout period helps prevent overdosage caused by overzealous demands for pain relief. The lockout time should be long enough for the previous dose to have its full effect. In view of the high intrinsic potency of fentanyl, it may be reasonable to use a longer lockout period (15 to 20 minutes). Regular review is needed in every case to ensure that pain relief is safe and adequate. Meperidine is not recommended because of the risk of central nervous system (CNS) toxicity from its metabolite normeperidine. Methadone is also not recommended for use in IV PCA, because its long elimination half-life (30 ± 19 hours) leads to marked drug accumulation with repeated dosing and therefore increased risk of opioid overdose compared with shorter-acting agents such as morphine or hydromorphone.

TABLE 14.1

Equianalgesic Doses of Commonly Used Opioid Analgesics

Opioid Analgesic	Parenteral Dose (mg) = 10 mg Morphine (IM/IV)	Oral Equivalent (mg)	Approximate Plasma T Elimination (hr)
Morphine	10	30	3
Codeine	NA	200	3
Fentanyl	0.1	NA	4
Hydrocodone	NA	30	4.5
Hydromorphone	2	6	2.5
Oxycodone	NA	20	3
Methadone	Equianalgesic doses of methadone vary markedly with dose and between individuals. Consultation with a pain or palliative care specialist is recommended if practitioner is unfamiliar with methadone prescribing.

IM, Intramuscular; IV, intravenous; NA, not applicable.

Basal (continuous) infusion of opioid, in addition to intermittent PCA bolus doses, is rarely indicated for acute pain in opioid-naïve patients. Use of a basal opioid infusion does not decrease the number of patient-activated PCA opioid doses, so the total dose of opioid is increased. Opioid basal infusion increases the risk of opioid adverse effects, including respiratory depression. Although practices may vary, basal opioid infusions are seldom used in PCA except in patients with chronic pain and established opioid tolerance. For example, if a patient on long-term oral opioid therapy for chronic pain requires surgery and will not be able to take the usual oral medication for some period, a basal opioid infusion may be used to administer an opioid equivalent to the chronic opioid dose, with the supplemental PCA bolus opioid titrated to control acute pain.

Acetaminophen

APAP has been available as an analgesic and antipyretic agent since the 1950s. It is indicated for the short-term management of mild to moderate pain and for reduction of fever in both children and adults, and it is the most commonly prescribed analgesic and antipyretic. Although the mechanism of APAP-mediated pain relief is still not completely understood, it has been shown that APAP rapidly enters the CNS, where it appears to have multiple actions that impact pain-signal transmission; these include (1) central inhibition of prostaglandins via the COX pathway, (2) enhancement of the descending serotonergic inhibitory pain pathways, (3) triggering of indirect activation of cannabinoid CB1 receptors, and (4) inhibition of nitric oxide pathways through NMDA or substance P.

IV APAP was first introduced in the United States in 2010, although it was widely available in more than 60 countries before it received U.S. Food and Drug Administration (FDA) approval. Although oral and rectal formulations of APAP are effective, IV administration leads to faster onset of effect: the onset is within 15 minutes for analgesia and 30 minutes for fever reduction. The literature has been mixed on whether this faster onset may confer a clinical benefit over other dosing routes in the perioperative care of head and neck surgery. For example, following oral surgery, IV APAP had a faster onset of analgesia and was more effective in reducing pain intensity in the first hour of treatment than oral APAP. IV APAP also reduced the need for rescue doses of opioid following tonsillectomy or endoscopic sinus surgery. However, results from a prospective, randomized clinical trial studying the analgesic effects of IV APAP versus placebo for endoscopic sinus surgery were inconclusive. It is also important to consider that significant increased cost for IV APAP may factor into limiting its use when compared with cost of oral APAP administration preoperatively 1 to 2 hours prior to surgery.