Perioperative opiate requirements in children with previous opiate infusion

Summary Background:  Critically ill children often require continuous opiate infusions. Tolerance may develop requiring a weaning strategy to prevent withdrawal symptoms. These children may also require subsequent surgical procedures. This is the first study to investigate whether previously opiate-tolerant patients require higher doses of opiates for adequate pain management perioperatively. Methods:  A retrospective study was conducted at a tertiary children’s hospital to investigate whether children previously exposed to continuous opiates for 10 or more days with subsequent weaning from those opiates will have similar or increased perioperative opiate requirements when compared to opioid-naive controls. Study patients included 31 children with previous continuous opiate exposure for 10 or more days followed by weaning and without signs of withdrawal for at least 72 h prior to the surgical procedure. Excluded were patients over 18 years of age, those whose surgical procedures would be unlikely to require perioperative opiates, oncological patients, burn patients, neurologically devastated patients, and patients who received regional anesthesia in addition to perioperative narcotics. The control group consisted of 31 age- and case-matched opiate-naive patients who underwent a surgical procedure during a similar time frame as the study patient. The medication administration record was reviewed for the length of continuous opiate exposure, date of last opiate use prior to a subsequent surgical procedure, and opiate use during the perioperative period. Opiate use was calculated as morphine equivalents per kilogram body weight (MSEQ·kg−1). The Wilcoxon rank sum test was used for univariate comparisons between matched pairs, and P-values <0.05 were considered statistically significant. Results:  The perioperative opiate requirements in opiate-exposed patients (median, interquartile range: 0.14, 0.08–0.25 MSEQ·kg−1) were not significantly different from opiate-naive patients (median, interquartile range 0.10, 0.05–0.2 MSEQ·kg−1, P = 0.19). Pain scores indicated that patients were generally comfortable in the perioperative period. Conclusions:  The perioperative opiate requirements of pediatric patients who were successfully weaned after prolonged opiate use were similar to opiate-naive patients. A history of prolonged opiate use alone does not necessitate special pain management for future procedures.