Intraoperative Systemic Physiological Abnormalities in Patients Undergoing Daytime versus Nighttime Emergency Surgery for Acute Traumatic Brain Injury: A Retrospective Study

Secondary insults from systemic physiological abnormalities occur frequently in acute traumatic brain injury (TBI). Emergency TBI surgeries are performed both during the day and night. Although literature exists on the timing of surgery and outcomes, data specifically focusing on intraoperative physiological abnormalities are limited. We compared intraoperative systemic physiological variables and perioperative laboratory parameters in patients undergoing daytime and nighttime TBI surgery. This retrospective study was conducted over 1 year following ethics approval. Surgeries performed between 8 AM and 8 PM were considered “daytime.” We collected data from the anesthesia information management system on heart rate (HR), blood pressure (BP), oxygen saturation (Spo2), end-tidal carbon-dioxide (ETCO2), temperature, fluid balance, blood loss, tranexamic acid use, blood transfusion, and pre- and postoperative laboratory parameters. Six-hundred fifty-one patients (day = 308, night = 343) were recruited. The durations of physiological monitoring were longer during daytime TBI surgery than during nighttime TBI surgery. The duration of BP above 20 and 30% of baseline (mean difference [MD] = 6.77 min; p <0.001 and MD = 3.24 min; p = 0.012, respectively) and mild hypocapnia (MD = 34.48 min; p = 0.009) was longer, and intraoperative fluid balance (MD = 200.36 mL; p = 0.025) was higher during daytime surgery. Preoperative leucocyte count (MD = 0.85 cells/µL; p = 0.017) and glucose (MD = 4 mg/dL; p = 0.019) were higher, while protein (MD = −0.1 g/dL; p = 0.036) and chloride (MD = −0.9 mEq/L; p = 0.030) values were lower in nighttime surgical patients. Differences in the durations of monitoring between daytime and nighttime emergency TBI surgeries likely reflect differences in the surgery/anesthesia durations, while differences in other variables probably reflect variations in physiological responses to TBI.