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  1. Describe the elements of pain assessment in critically ill patients.

  2. Describe how to use a behavioral pain scale to assess pain in patients who cannot self-report.

  3. Compare and contrast pain-relieving modalities for the critically ill:

    • Nonsteroidal anti-inflammatory drugs

    • Opioids, including patient-controlled analgesia (PCA)

    • Epidural analgesia with opioids and/or local anesthetics (LAs)

    • Elastomeric pumps with local anesthetic (LA)

    • Nonpharmacologic modalities: distraction, cutaneous stimulation, imagery, and relaxation techniques

  4. Identify the important elements of pain control for a patient who is an addict, dependent on opioids for pain relief, on medication management for opioid addiction, or has a past history of substance abuse.

  5. Describe special considerations for pain management in vulnerable populations such as the older adults.

  6. Identify the need for sedation, commonly used sedatives and potential complications.

  7. Discuss how to monitor and manage patients’ requiring sedation and interventions to prevent potential complications.

  8. Discuss different neuromuscular blocking agents used in critically ill ventilated patients, clinical indications, and monitoring.


Pain management is central to the care of the critically ill or injured patient. Often, critically ill patients are not able to self-report their pain management needs to their healthcare team. Patients identify physical care that promotes pain relief and comfort as an important element of their hospitalization and recovery, especially while in the critical care environment. Providing optimum pain relief for critically ill patients not only enhances their emotional well-being, but can also help avert additional physiologic injury for a patient who is already compromised. This chapter explores a multimodal approach to pain management in critically ill patients based on the physiologic mechanisms of pain transmission and human responses to pain. Specific pharmacologic and nonpharmacologic pain management techniques are described, including the integral relationships among relaxation, sedation, and pain relief. Strategies also are presented that promote comfort and are easy to incorporate into a plan of care for critically ill patients. Finally, special considerations are delineated for vulnerable populations within the critical care setting.


Peripheral Mechanisms

The pain response is elicited with tissue injuries, whether actual or potential. Undifferentiated free nerve endings, or nociceptors, are the major receptors signaling tissue injury (Figure 6-1). Nociceptors are polymodal and can be stimulated by thermal, mechanical, and chemical stimuli. Nociception refers to the transmission of impulses by sensory nerves, which signal tissue injury.

Figure 6-1.

Physiologic pathway of pain transmission. (Reproduced with permission from Copstead L. Perspectives on Pathophysiology. Philadelphia, PA: WB Saunders; 1995.)

At the site of injury, the release of a variety of neurochemical substances potentiates the activation of peripheral nociceptors. Many of these substances are also mediators of the inflammatory response and they can facilitate or inhibit the pain impulse. These substances include histamine, kinins, prostaglandins, serotonin, and leukotrienes (Figure 6-2).


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