Behavioral pain scales, vital signs, and pupilometry to pain assessment in the critically ill patient: A cross sectional study.

Abstract

Background: Detecting pain in sedated critically ill patients requires utmost attention.

Aim: To assess the pain in mechanically ventilated critically ill patients with the Behavioral Pain Scale (BPS), Behavioral Indicators Pain Scale (ESCID), the pupillary dilation response (PDR), and vital signs.

Design: Cross-sectional study METHODS: The study was conducted between March and December 2019, involving patients with a baseline BPS of 3, ESCID of 0, and RASS between -1 and -4. Patients with mobility limitations or altered pupillary reflexes were excluded. We measured before and after non-painful stimulation (NP) followed by 10-20-30-40 mA stimuli and endotracheal aspirate (ETA). The primary outcome was the pain measured with BPS and ESCID scales and PDR with AlgiScan® pupilometer defined as BPS≥4, ESCID≥1, and PDR≥11,5 %. We performed a descriptive study and analyzed the agreement between pain detection methods.

Results: Thirty-one patients were included, and 183 measurements were recorded. The scales showed minimal changes. Approximately 30 % of patients reported pain at a 30 mA stimulus, increasing to over 70 % after ETA. The PDR ranged from 2 % to 6-33% on the ETA, even in pain-free patients, with pain incidence between 70 % and 100 % for the 40 mA and ETA stimuli. Vital signs did not show relevant changes. The PDR had over 90 % agreement with scales for no pain. For higher-intensity stimuli, agreement ranged from 60 % to 80 %. Disagreement occurred when there was no pain by scales (BPS<4; ESCID<1) and pain with PDR (PDR≥11.5).

Conclusions: Pain behavioral scores and vital signs were low in critically ill patients. PDR detected a nociceptive pain response in no-pain patients.