Respiratory depression following epidural morphine in an infant of three months of age

Abstract

Epidural administration of combinations of opioids and a local anaesthetic provides prompt and effective analgesia and is increasingly used in paediatric anaesthesia. However, respiratory depression by rostral spread of opioid in the CSF is by far the greatest concern after epidural morphine. An infant of three months of age underwent portoenterostomy (Kasai's operation) for extrahepatic biliary duct atresia. A median approach at the L3-L4 epidural interspace was used and a dose of 1 ml.kg-1 of 0.125% bupivacaine with adrenaline 1:400000 mixed with 50 micrograms.kg-1 morphine was injected using a 19 gauge Tuohy needle. Six h after epidural morphine, the infant developed respiratory depression with an increase in drowsiness, miosis and decreased respiratory rate. Low arterial saturation (SpO2) was detected by pulse oximetry and confirmed by blood gas analysis. An intravenous bolus of 5 micrograms.kg-1 naloxone followed by a 3-h infusion of 2 micrograms.kg-1.h-1 resulted in complete reversal of signs and symptoms of respiratory depression. Epidural opioids should be limited to paediatric patients admitted to specialized recovery units for the first postoperative day.