The Unconscious Or Critically Ill Patient
Unstable and unresponsive patients pose several additional challenges. Their ability to communicate may be impaired, and, as previously discussed, there are few reliable, objective signs of pain.134 Pain in an intubated or obtunded patient may manifest as agitation. It should be considered as a possible etiology for vital sign derangements (eg, tachycardia or hypertension), but there are generally confounding medical problems in these patients that may need to be addressed as well. Hypotensive patients pose additional challenges, as many analgesics will lower blood pressure. Careful titration and judicious use of more hemodynamically stable agents like fentanyl or ketamine may provide a reasonable approach.18,21,73
Traumatic Abdominal Pain
Patients have been fighting an uphill battle for adequate analgesia with abdominal pain since Cope proselytized this philosophy in 1921.135 At the time, despite a dearth of evidence to support the practice, surgeons were reticent to provide analgesia for fear of masking important physical examination findings. Effective pharmacologic dosing was not as well studied at that time either. Fortunately, since then, a great deal of information has refuted this practice, and, in the most recent editions of Cope’s book, this recommendation has been amended.
Pain treatment does not obscure abdominal examination findings,64 does not contribute to increased morbidity or mortality,136-138 and, in fact, may improve diagnostic accuracy.139 A recent Cochrane review of 8 randomized double-blind controlled trials, totaling 922 patients, concluded that opioid analgesia “does not increase the risk of making unsuitable treatment decisions” and significantly improves patient comfort when compared to placebo.140 With the advent of more advanced evaluation techniques, specifically computed tomography (CT), the concern for missed serious occult injuries has dwindled. This is evidenced by a Level B recommendation by the American College of Emergency Physicians (ACEP) that discharge may be safe for stable blunt abdominal trauma patients after a negative abdominal CT.141
Pain control in pediatric patients warrants an entire review of its own; however, it is worth discussing some additional considerations when managing analgesia in younger children. It is recognized that pain medication administration remains inadequate in children, often even more so than adults.8,142-144 In addition, anxiety often plays a larger role in younger children who have less insight into their condition. Thus, anxiolysis (by pharmacologic or nonpharmacologic means) should be emphasized in addition to analgesia. Distraction (eg, games, toys, or videos), a calm demeanor, and parental presence may help achieve this goal.
Observational and retrospective studies have shown that, for a variety of reasons, older patients are less likely to receive appropriate analgesia.145,146 They may have physical or cognitive impairments that complicate pain assessment or a cultural resistance to “complaining.” Untreated pain increases the incidence of delirium, increases length of stay, and worsens patient outcomes. A study by Duggleby and Lander of 60 geriatric postoperative hip replacement patients showed that mental status declined in relation to pain, independent of analgesic administration.147 In fact, in 541 hip fracture patients studied by Morrison et al, delirium was increased with decreasing doses of opioids.148
Older patients tend to have more comorbidities and are more likely to take medications that may cause unwanted medication interactions.149 Compounding this, they may also have decreased renal or hepatic metabolism, decreased body mass, and leaner body composition.150
Clinicians often harbor a valid concern for overmedication, as older patients may be more susceptible to side effects. Opioids should be used when appropriate, but careful attention must be paid to their effects on mental status, respiratory depression, and constipation. Titrated, smaller doses are preferred to larger boluses for this reason.
NSAIDs have fewer concerns for mental status changes or respiratory depression and may be considered for minor pain. They are not without risks, however, including medication interactions, increased risk of renal failure,151 hypertension, and sodium retention, which may precipitate congestive heart failure.152 Therefore, caution is advised when prescribing NSAIDs for patients with a history of renal insufficiency or congestive heart failure, and they should be avoided if an alternative agent is available.
Prescription drug abuse in the United States has become epidemic,153 and opioid pain relievers alone accounted for 14,800 deaths in the United States in 2008.154 Consequently, many clinicians carry reasonable concerns when prescribing narcotics in the absence of objective evidence of pain. Many conditions, including some traumatic injuries, may not provide such evidence.7 Acute treatment is not necessarily associated with chronic dependence or abuse.155,156 In fact, adequate treatment of acute pain may prevent the development of chronic pain, which is a risk factor for subsequent opioid misuse.
It may be simple to maintain a position of treating all patients, without harboring a concern for opioid abuse. Unfortunately, the consequences of opioid abuse are dire, and the death rate continues to rise dramatically. It is tempting to place the burden of judgment on the abuser, but, realistically, the prescriber plays an equally important role. Fortunately, patients with true drug-seeking behavior represent a minority of ED visitors.
Several strategies have been described to deal with patients suspected of seeking narcotics for nonmedical use.157 This may include database tracking (provided by most states), narcotic contracts, or referral to treatment programs. ED providers may limit the amount of medication dispensed and encourage follow-up with a primary care provider or pain specialist. Addressing safe and secure storage may provide additional benefit, as it is known that patients do not store or dispose of medications properly,158 and this is a major source of drug diversion.159
There is no simple solution or pathway to determine when it is appropriate to dispense opioid pain medication, and there is a great deal of heterogeneity in practice. The clinician must use his judgment and remain vigilant, but compassionate. Most recommendations suggest that the ED providers’ clinical responsibility outweighs any assumed responsibility to police societal misbehavior.10
Patients With Chronic Pain
Patients with chronic pain may present with acute exacerbations or novel injuries. In either case, their underlying condition complicates treatment. In most cases, it is not realistic to expect complete resolution of a chronic condition in an ED situation, and this explanation may save both parties grief later in the encounter. Expectations may be managed by creating a mutually agreeable endpoint (eg, 4/10 pain or improved mobility, etc).
It has been observed that “all chronic pain starts as acute pain.”160 Rivara and Mackenzie reported in a longitudinal study from 69 trauma centers (3047 patients) that 62.7% of patients had injury-related pain 12 months after their initial injury, with increased prevalence in women and those with depression.161 Adequate initial pain control may decrease the likelihood to develop chronic painful conditions.
Complex regional pain syndrome (CPRS) is a chronic, progressive, painful disorder associated with autonomic dysfunction. It is classified into 2 types: type I (formerly called reflex sympathetic dystrophy [RSD] or algodystrophy), which has no measurable nerve damage; and type II, which has evidence of nerve damage. Often, trauma, surgery, or immobilization is an inciting factor. The condition causes severe pain, edema, and skin changes. Treatment is very difficult, as this condition is often resistant to pharmacotherapy.162
There is some evidence to support treatment with calcitonin. A meta-analysis of 21 randomized controlled trials totaling 629 patients by Perez et al suggested a benefit for treatment of CRPS, but there was a large degree of heterogeneity between trials and small sample sizes.163 Hamamci et al also found a benefit in a randomized placebo-controlled trial of 41 patients that was not included in Perez’s analysis.164
Corticosteroids and bisphosphonates have shown benefit in small randomized double-blind placebo-controlled trials. Christensen et al randomized 23 patients to receive either 10 mg prednisone 3 times daily or placebo and showed significant improvement in pain over 12 weeks.165 Adami et al demonstrated benefit of 3 days of IV alendronate in 20 patients,166 and Varenna et al showed improvement in pain scores in 32 patients treated for 10 days with IV clodronate.167
Two Cochrane reviews have looked at nerve disruption techniques for pain management in CPRS and found insufficient evidence to confirm a benefit.168,169 For the emergency clinician, the most important intervention is recognition of the syndrome and expeditious referral to a pain management specialist for continued treatment.
Phantom limb pain occurs in up to 80% of patients after amputation, and appropriate treatment may decrease the incidence.170-172 While opioids are often used for pain management, they have a significant side-effect profile, as previously described. Calcitonin has been suggested as a preferred treatment. Its antinociceptive activity is caused by elevation of beta-endorphins. In a double-blinded crossover trial of 21 patients by Jaeger and Maier, it provided better pain control than placebo.173
Knox et al reported a case of phantom limb pain controlled with ketamine.174 Subsequently, it showed significant pain reduction in a randomized placebo-controlled crossover trial of 11 patients by Nikolajsen et al.175 Eichenberger et al demonstrated superiority of ketamine over placebo or calcitonin in 20 patients.176 In a small study by Ben Abraham et al, 10 patients showed statistically significant improvement of phantom limb pain by treatment with dextromethorphan, compared to placebo.177
A Cochrane review pooled results from 2 trials totaling 43 patients to evaluate the effect of gabapentin. It found a nonsignificant trend toward benefit, and further trials may help establish its role.178 Case reports suggest that benzodiazepines may be useful adjunctive therapy.179,180 No benefit was found from amitriptyline, compared to placebo, by Robinson et al in 39 patients, and it was associated with dry mouth and dizziness.181