Prediction of Nociception in Children Using the Nociceptive Flexion Reflex Threshold and the Bispectral Index-A Prospective Exploratory Observational Study*

Objectives: The prediction of patient responses to potentially painful stimuli remains a challenge in PICUs. We investigated the ability of the paintracker analgesia monitor (Dolosys GmbH, Berlin, Germany) measuring the nociceptive flexion reflex threshold, the cerebral sedation monitor bispectral index (Medtronic, Dublin, Ireland), the COMFORT Behavior, and the modified Face, Legs, Activity, Cry, Consolability Scale scores to predict patient responses following a noxious stimulus. Design: Single-center prospective exploratory observational study. Setting: Fourteen-bed multidisciplinary PICU at the University Children's Hospital, University Medical Center Hamburg Eppendorf, Germany. Patients: Children on mechanical ventilation receiving analgesic and sedative medications. Interventions: Noxious stimulation by way of endotracheal suctioning. Measurements and Main Results: Two independent observers assessed modified Face, Legs, Activity, Cry, Consolability and COMFORT Behavior Scales scores during noxious stimulation (n = 59) in 26 patients. Vital signs were recorded immediately before and during noxious stimulation; bispectral index and nociceptive flexion reflex threshold were recorded continuously. Mean prestimulation bispectral index (55.5; CI, 44.2-66.9 vs 39.9; CI, 33.1-46.8; p = 0.007), and COMFORT Behavior values (9.5; CI, 9.2-13.2 vs 7.5; CI, 6.7-8.5; p = 0.023) were significantly higher in observations with a response than in those without a response. Prediction probability (P-k) values for patient responses were high when the bispectral index was used (P-k = 0.85) but only fair when the nociceptive flexion reflex threshold (P-k = 0.69) or COMFORT Behavior Scale score (P-k = 0.73) was used. A logistic mixed-effects model confirmed the bispectral index as a significant potential predictor of patient response (p = 0.007). Conclusions: In our sample of ventilated children in the PICU, bispectral index and nociceptive flexion reflex threshold provided good and fair prediction accuracy for patient responses to endotracheal suctioning.