ABSTRACT
This chapter discusses some drugs and focuses mainly on mechanisms and assessment of pain. Pain is undesirable, a physical and psychological phenomenon that can cause physiological as well as psychological complications. Pain from physiological causes is sensed by nociceptors, specialised nerve endings found throughout the body, especially skin and superficial tissues. The Behavioral Pain Scale Tool assesses facial expression, upper limb movements and compliance with ventilation, so is useful for assessing pain in ventilated patients, although weakness/immobility and pathology may mask any or all of these signs, some of the criteria for assessing tolerance of ventilation are questionable, and it necessarily assumes that patients are conscious enough to move limbs. Many intensive care unit patients are unable to perform even fundamental activities of living, so managing pain should include comfort measures, such as: smoothing creases in sheets, turning pillows over, and reducing noise and light.
