Le réflexe photomoteur pour évaluer l’état analgésique des patients traumatisés crâniens sédationnés et incapables de communiquer à l’unité des soins intensifs
Background: Analgesia monitoring is essential to preserve comfort in critically ill sedated patients with traumatic brain injury (TBI). While pupil dilation (PD) and pain behaviors can be used to assess analgesia, these indicators require application of noxious stimulations. Recently, the pupillary light reflex (PLR) has emerged as a non-noxious parameter that may be used to predict analgesia requirements in non-brain-injured patients. Here, we investigated whether PLR can be used for the purpose of analgesia monitoring in critically ill sedated TBI patients. Methods: Fifteen mechanically ventilated TBI patients (11 men; 54±20 years) under perfusions of analgesia and sedation were assessed at predefined time within 72 hours of intensive care unit admission. Data collection was performed using video-pupillometry and the Behavioral Pain Scale (BPS). At each assessment, pupil size and PLR at rest were recorded followed immediately by the documentation of PD and pain behaviors elicited by a calibrated noxious stimulation. Blood concentrations of analgesics/sedatives were monitored. Results: 103 assessments were completed. PLR resulted in an average decrease of -19% in pupil diameter and PD resulted in average increase of +10%. Variations in PLR and PD were more pronounced in participants who showed a BPS score > 3 (a recognized sign of sub analgesia) compared to those with no behavioral reaction. Multiple regression analyzes showed a significant overlap between fluctuations in pupillary reflexes and blood levels of fentanyl, not propofol. Conclusions: PLR may be useful to assess analgesia requirements before a nociceptive procedure in critically ill sedated patients with TBI.
Pupillometry Analgesia Pain Traumatic brain injury