No abstract

Summary Sixty boys aged up to 9 years undergoing orchidopexy were randomly allocated to receive one of three solutions for caudal epidural injection: group A received 1 ml. kg−1 of 0.25% bupivacaine with 0.25 mg. kg−1of preservative‐free ketamine, group B received 1 ml. kg−1 of 0.25% bupivacaine with ketamine 0.5mg. kg−1 and group C received 1 ml. kg−1 of 0.25% bupivacaine with 1 mg. kg−1 of ketamine. Postoperative pain was assessed by means of a modified Objective Pain Score and analgesia was administered if this score exceeded four. The median duration of caudal analgesia was 7.9h in group A, 11 h in group B and 16.5 h in group C. There were no differences between the groups in the incidence of motor block, urinary retention, postoperative vomiting or postoperative sedation. Group C had a significantly higher incidence of behavioural side effects, including slightly odd behaviour, vacant stares and abnormal effect than groups A and B.

Sixty boys, aged 1-10 yr, undergoing orchidopexy were allocated randomly to receive one of three solutions for caudal extradural injection. Group A received 0.25% bupivacaine 1 ml kg-1 with adrenaline 5 micrograms ml-1 (1/200,000), group C received 0.25% bupivacaine 1 ml kg-1 with clonidine 2 micrograms kg-1 and group K received 0.25% bupivacaine 1 ml kg-1 with ketamine 0.5 mg kg-1. Postoperative pain was assessed using a modified objective pain score and analgesia was administered if this score exceeded 4. The median duration of caudal analgesia was 12.5 h in group K compared with 5.8 h in group C (P < 0.05) and 3.2 h in group A (P < 0.01). There were no differences between the groups in the incidence of motor block, urinary retention or postoperative sedation.

Forty children aged 6-12 yr undergoing appendicectomy were allocated randomly to receive postoperative i.v. morphine by a patient-controlled analgesia (PCA) system (bolus dose 20 micrograms kg-1 with a lockout interval of 5 min) or the same PCA with a background infusion of morphine 20 micrograms kg-1 h-1. Patients breathed air and oxygen saturation was monitored by continuous pulse oximetry. Scores for pain, sedation and nausea were recorded hourly. Patients with PCA + background infusion received significantly more morphine than those with PCA only. Both groups self-administered similar amounts of morphine using the PCA machine. There were no significant differences in the pain scores of the two groups. Patients with PCA+background infusion suffered more nausea (P < 0.01), more sedation (P < 0.05) and hypoxaemia (P < 0.001) than those with PCA only. They also had a better sleep pattern than those with PCA only.