Procedure time-of-day effects on postoperative opioid requirements in children

Postoperative analgesic requirements in adults follow circadian rhythm patterns with requirements for opioids and local anesthetics highest in the morning. Procedure time of day may also potentially affect circadian rhythm patterns with surgery at night promoting wakefulness during nighttime hours. This disruption may produce a shift in the circadian rhythm and potentially affect when postoperative opioid requirements are highest. We hypothesized that children undergoing surgery at night would have higher postoperative opioid requirements during nighttime hours secondary to a shift in the circadian rhythm with those requirements remaining higher than daytime requirements for the duration of the hospital stay.

A retrospective cohort was completed on all children aged 1-18 years undergoing a laparoscopic appendectomy for complicated appendicitis between January 2018 and December 2019. Outcomes were total postoperative morphine equivalents (mg/kg), including total daytime and nighttime postoperative morphine equivalents (mg/kg) in children undergoing surgery during the day and at night.

There were 999 children who underwent a laparoscopic appendectomy for complicated appendicitis at Texas Children's Hospital from January 1, 2018 to December 31, 2019. Of these, 758 children underwent the procedure during the day and 241 children at night. The total, daytime, and nighttime median morphine equivalents (mg/kg) for children undergoing an appendectomy during the day were 0.1 (0.0-0.4), 0.0 (0.0-0.2), 0.1 (0.0-0.2), respectively. The total, daytime, and nighttime morphine equivalents (mg/kg) for children undergoing an appendectomy at night were 0.2 (0.0-0.5) (p = -0.01), 0.1 (0.0-0.3) (p = 0.01), and 0.1 (0.0-0.2) (p = 0.03), respectively. All children, irrespective of the procedure time of day, required more morphine equivalents during daytime hours than during nighttime hours.

We found that procedure time of day did not impact postoperative opioid requirements in children undergoing a laparoscopic appendectomy for complicated appendicitis. Both children undergoing an appendectomy during the day or at night required more morphine equivalents during daytime hours than during nighttime hours. Surgery at night did not produce a shift in opioid requirements postoperatively from daytime hours to nighttime hours in children undergoing an appendectomy at night.