Pain assessment in the critically ill ventilated adult: validation of the Critical-Care Pain Observation Tool and physiologic indicators

Clin J Pain. 2007 Jul-Aug;23(6):497-505. doi: 10.1097/AJP.0b013e31806a23fb.


Objectives: Use of a valid behavioral measure for pain is highly recommended for critically ill, uncommunicative adults. The aim of this study was to validate the English version of the Critical-Care Pain Observation Tool (CPOT) and physiologic indicators [mean arterial pressure, heart rate, respiratory rate, and transcutaneous oxygen saturation (SpO(2))] in critically ill ventilated adults.

Methods: A total of 30 conscious and 25 unconscious patients in the intensive care unit participated in the study. Patients were assessed by staff nurses and research team members before, during, and 20 minutes after the 2 following procedures: (1) nociceptive procedure: turning, and (2) non-nociceptive procedure: taking noninvasive blood pressure (NIBP). Conscious ventilated patients provided self-report level of pain.

Results: Interrater reliability of the CPOT was supported with high intraclass correlation coefficients (0.80 to 0.93). Discriminant validity was supported with increases of the CPOT and physiologic indicators, and a decrease in SpO(2) during turning, but remaining stable during NIBP. Conscious patients had higher CPOT scores during turning compared with unconscious patients. For criterion validity, the CPOT scores were correlated to the patients' self-reports of pain, whereas physiologic measures were not. Using a CPOT cutoff score of >3 yielded a sensitivity of 66.7% and a specificity of 83.3%.

Discussion: The CPOT is a reliable and valid tool to assess pain in critically ill adults. Behavioral indicators represent more valid information in pain assessment than physiologic indicators. Further research is needed to explore how specific critically ill populations (eg, head injury) react to a painful procedure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analgesics, Opioid / therapeutic use
  • Analysis of Variance
  • Blood Pressure / physiology
  • Consciousness
  • Critical Care / psychology*
  • Cross-Over Studies
  • Data Interpretation, Statistical
  • Female
  • Heart Rate / physiology
  • Humans
  • Hypnotics and Sedatives / therapeutic use
  • Male
  • Middle Aged
  • Nurses
  • Observer Variation
  • Oxygen / blood
  • Pain Measurement / methods*
  • Reproducibility of Results
  • Respiration, Artificial / psychology*
  • Respiratory Mechanics / physiology


  • Analgesics, Opioid
  • Hypnotics and Sedatives
  • Oxygen