Chapter 35: Acute Pain Management

INTRODUCTION

Pain is the most common presenting symptom for patients coming to the ED, with 75% to 80% of all patients having pain as their primary complaint.¹ Despite increasing research and information about pain management, oligoanalgesia, or the under treatment of pain, persists.^2,3,4,5 While all patients are susceptible to oligoanalgesia, certain subgroups, such as ethnic minorities, the aged, the very young, and those with diminished cognitive function, are more at risk (Table 35-1).^6,7,8,9 Pain management is further influenced by concerns of prescription opioid misuse, a rising concern in all age groups but most notably in adolescents and young adults. Pain and addiction are not mutually exclusive,¹⁰ and appropriate treatment of acute pain should not be withheld for fear of facilitating drug misuse.

Specific measures to treat pain should occur in addition to, and at the same time as, treatment of the underlying illness or injury. It is not possible to generalize the extent and quality of pain control needed for a specific patient. For example, pain is an indicator of ongoing cardiac ischemia, and the goal should be to eliminate all pain. On the other hand, a patient with a traumatic injury may choose to endure more pain out of personal or cultural beliefs. Physicians may limit analgesics in those with head injuries to perform serial neurologic examinations. Whenever possible, medications that act on specific sites that initiate the pain signal—a mechanistic approach—are preferred to agents such as opioids that mask pain, which is a symptomatic approach. Current migraine treatment is an excellent example of the mechanistic approach; preferred treatment includes a serotonin agonist (triptan)¹¹ or a dopamine antagonist (phenothiazine),¹² rather than opiates.^13,14

PATHOPHYSIOLOGY

Pain is the physiologic response to a noxious stimulus, whereas suffering—the expression of pain—is modified by the complex interaction of cognitive, behavioral, and sociocultural dimensions. Individual pain experience is therefore not static, but varies depending on current and past medical history, physical and emotional maturity, cognitive state, meaning of pain, family attitudes, culture, and environment. Emotions can modify pain either negatively or positively: fear and anxiety may accentuate pain, or pain can be suppressed completely if an essential task must be performed ...