EFFECTS OF FENTANYL ADMINISTRATION ON RESPIRATORY SYSTEM COMPLIANCE IN INFANTS

Objective. To determine if the analgesic doses of fentanyl used in a p ediatric intensive care unit (ICU) setting adversely affect dynamic to tal respiratory system compliance in awake, intubated infants. Design: Prospective case-control study. Setting. Pediatric and pediatric card iac ICUs of a tertiary university hospital. Patients. Thirteen awake a nd mechanically ventilated children <6 months of age. Interventions: M easurements of dynamic total respiratory system compliance were obtain ed during steady-state conditions for 6 mins and continued for 10 mins after the rapid, intravenous administration of 4 mug/kg of fentanyl. No patient had received a narcotic, benzodiazepine, or muscle relaxant within the previous 4 hrs. Measurements and Main Results: After fenta nyl administration, dynamic total respiratory system compliance was un changed in three patients, improved in nine patients, and deteriorated in one patient. The mean value for the entire group increased from 0. 76 mL/cm H2O/kg before infusion to 0.82 mL/cm H2O/kg after infusion (p < .02), representing a 9.6% increase. None of the patients showed oxy gen desaturation as assessed by continuous pulse oximeter, or episodes of chest wall rigidity. Conclusions: This work corroborates our clini cal impression that rapid infusions of fentanyl at the dose tested in small infants do not adversely affect dynamic total respiratory system compliance. To the contrary, the sedating and analgesic effects may i mprove synchronous breathing and decrease voluntary muscle tone, resul ting in improved dynamic total respiratory system compliance.