The assessment of pain can be challenging as it relies on patient communication of a subjective perception of an unpleasant sensory and emotional experience. The perception of pain varies widely between patients, and it cannot be objectively quantified. The goals of pain assessment are to gather information from the patient in a standardized way in order to help determine the type of pain, the effect this pain is having on the patient and their daily activities, and a cause of the pain so the provider may develop a suitable treatment plan. Standardizing pain assessments is important to obtain reliable, reproducible data that may be used to guide treatment and determine when changes are needed. Pain intensity and pain relief are the two characteristics typically assessed in acute pain. There are several one-dimensional pain scales physicians may use to assess pain intensity.
1 The Numerical Rating Scales (NRS), Verbal Rating Scales (VRS), Visual Analog Scales (VAS), and Faces Pain Scale (FACES) are the more commonly used intensity assessment tools for acute pain. Examples of these pain scales are shown in
Figure 47.1. The NRS, VRS, and FACES scales are relatively self-explanatory. The VAS requires the patient to point to an area on the line, which is then recorded in millimeters as their pain rating. When determining which scale to use, the physician should take into account the patient’s age, cognitive status, and communication barriers. Pain assessment
in patients with cognitive impairment or those unable to report such as unconscious or sedated patients present unique challenges. The tools recommended for these patients use behavioral and physiologic indicators to assess pain. The Critical-Care Pain Observation Tool shown in
Table 47.1 incorporates facial expression, body movements, ventilator compliance for intubated patients and vocalization in extubated patients, and muscle tension to determine a pain score between 0 and 8. The Behavioral Pain Scale uses facial expression, upper extremity movements, and compliance with mechanical ventilation to compile a pain rating between 0 and 12 (
Table 47.2). Infants and children present another group requiring behavioral and physiologic indicators to assess pain. The Face, Legs, Activity, Cry, Consolability (FLACC) or the Children’s Hospital of Eastern Ontario Pain Scale are recommended for assessing pain in children older than 3 years. Using indicators such as facial expressions, body movements, heart rate, and oxygen saturation is recommended when assessing acute pain in infants.