Comparison of the reinforced laryngeal mask airway and tracheal intubation for nasal surgery

Airway maintenance and protection during anaesthesia and recovery provided by the reinforced laryngeal mask airway was compared with the sequential use of a tracheal tube followed by the Guedel airway in 66 patients having anaesthesia for nasal surgery. One patient was withdrawn from the laryngeal mask group because the airway was difficult to position. All patients had an oropharyngeal pack inserted and Moffett's solution instilled into the nasal cavities. At the end of surgery the nasal cavities were packed. During operation airway maintenance was good and airway protection was equally effective in both groups. Contamination of the lower airway occurred in only five patients. During recovery from anaesthesia the laryngeal mask and Guedel airway were well tolerated by most patients, but only the mask laryngeal provided an unobstructed airway in all patients. The laryngeal mask protects the larynx from contamination during and after operation until the return of the patient's own protective reflexes.     

Patient-controlled analgesia in children. A comparison of two infusion techniques

The effectiveness of patient-controlled intravenous morphine with and without a supplementary fixed rate infusion was studied in 40 children after orthopaedic surgery and 40 children after abdominal surgery. The use of a background infusion after orthopaedic surgery, where the majority of children received intra-operative regional blockade, resulted in a higher total dose of morphine (P < 0.05) without evidence of improved analgesia, compared to PCA alone. Children receiving a background infusion after abdominal surgery showed evidence of improved sleeping patterns post-operatively compared with those receiving PCA alone, despite similar overall morphine consumption. There were no episodes of excessive sedation, or respiratory depression with the use of either regimen, and over 90% of the children studied were assessed as experiencing either no pain or mild pain. The suitability and efficacy of patient controlled analgesia for management of post-operative pain for children aged between 5 and 17 years appears to be confirmed. The use of a supplementary background infusion may be of value in children.     

Liver function and structure in survivors of acetaminophen poisoning

A series of 30 patients, hospitalized with acetaminophen overdose, were studied during initial admission and again three months later. The quantity of acetaminophen ingested varied from 5 to 50 g and 19 patients developed raised transaminase levels in the serum during the initial period. Liver damage, on the basis of needle biopsy findings, was categorized as severe in 5, moderate in 7, and mild or minimal in 18 patients. At three months' follow-up all but one of the biochemical indicatns of liver damage had reverted to normal in all patients. The exception was the serum total bile acids. Residual changes found on liver biopsy at three months were minimal and nonspecific, apart from one previously severely affected patient in whom there was evidence of scarring. It is concluded that in the usual spectrum of acetaminophen poisoning requiring hospitalization there is no evidence of lasting liver damage.Part of this work was supported by a grant from the University Hospitals Scientific and Research Committee.     

Factors influencing epidural catheter migration

The incidence and amount of migration of epidural catheters was investigated in a prospective randomised study of 153 women who required analgesia in labour. Inward or outward migration occurred in 36% of patients. Inward migration by 1-3 cm occurred in 21 (13.7%) patients and outward migration by 1 cm or more occurred in 34 (22.2%); three (2%) catheters migrated out through the skin. There were significant positive correlations between outward migration and weight, body mass index, and depth of the epidural space. There was no relationship between migration and height, age, intervertebral space used or duration of catheterisation. Problems with epidural block were no more likely in patients in whom migration of 1 cm or more occurred compared with those in whom migration was limited to a maximum of +/- 0.5 cm. However, the pattern of problems was different. All cases of failed epidural block occurred in patients whose epidural catheter migrated outward by 2.5 cm or more. Unilateral blockade was not more likely if migration of 1 cm or more occurred.