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Objective Nociceptive Assessment in Ventilated ICU Patients: A Feasibility Study Using Pupillometry and the Nociceptive Flexion Reflex
Published on: July 4, 2018
A Pilot Study on Pain Assessment Using the Japanese Version of the Critical-Care Pain Observation Tool
1Graduate School Department of Interdisciplinary Research, University of Yamanashi, Yamanashi, Japan.
Background:
Critically ill patients experience various types of pain that are difficult to assess because patients cannot communicate verbally due to artificial airways and sustained sedation. The Critical-Care Pain Observation Tool (CPOT) objectively evaluates patients' pain.
Aims:
This study aimed to re-assess the reliability and validity of the Japanese version (CPOT-J) and to reveal limitations of behaviors specific to mechanically ventilated patients.
Design:
Secondary analysis of observational pilot study and case report.
Participants:
METHODS: We obtained consent preoperatively from 40 cardiovascular surgery patients. CPOT-J scores were evaluated immediately before, immediately after, and 20 minutes after painful stimulation. Inter-rater reliability was determined by the researcher and 18 ICU nurses (minimum one-year ICU experience). Validity was examined by comparing CPOT-J with vital sign values and patients' self-reports of pain. Two cases revealed the tool's characteristics: one score was consistent with patient reports while the other was not.
Results:
We evaluated pain in 34 patients (26 men, 8 women; mean age = 66.8 years). Weighted kappa scores ranged from 0.48 to 0.94. The tool only correlated with changes in systolic blood pressure and pulse pressure. Case studies indicated that the tool effectively evaluated mid-sternum-wound pain, but not back pain at rest.
Conclusions:
The CPOT-J can assess pain in mechanically ventilated patients, but being immobile results in a score of 0 for body movement (e.g., being immobile while feeling back pain) and is a limitation of the scoring.

