J. Roger Maltby

Multicenter Study of General Anesthesia. II. Results

A prospective, stratified, randomized clinical trial of the safety and efficacy of four general anesthetic agents (enflurane, fentanyl, halothane, and isoflurane) was conducted in 17,201 patients (study population). Patients were studied before, during, and after anesthesia for up to 7 days. Nineteen patients died (0.11%), and in seven of these (0.04%) the anesthetic may have been a contributing factor. The rates of death, myocardial infarction, and stroke in the study population were so low (less than 0.15%) that no conclusions regarding the relative rates of these outcomes among the four anesthetic agents could be reached. The rates of 16 of 66 types of adverse outcomes in the study population were significantly different among the four study agents. Most of these outcomes were minor. However, severe ventricular arrhythmia (P less than 10(-6)) was more common with halothane, severe hypertension (P less than 10(-6)) and severe bronchospasm (P = 0.028) were more common with fentanyl, and severe tachycardia (P = 0.001) was more common with isoflurane. Recovery from anesthesia during the first 30 min was slowest in those patients who received halothane (P less than or equal to 0.001). In addition, patients who received fentanyl experienced less pain during the first hour in the recovery room (P less than 10(-6)). In conclusion, clinically important differences do exist for some outcomes among the four study agents.

Effect of oral liquids and ranitidine on gastric fluid volume and pH in children undergoing outpatient surgery

Eighty-eight children (mean age 5.6 yr, range 1-14 yr) about to undergo elective outpatient surgery were randomly assigned to four groups. All children were given phenolsulfonphthalein (PSP) orally 2-3 h before the scheduled time of surgery as a marker dye to assess gastric emptying. Immediately after receiving PSP they were given: group A--liquids, up to 5 ml/kg + placebo (glucose water 0.2 ml/kg); group B--liquids, up to 5 ml/kg + ranitidine 2 mg/kg in glucose water 0.2 ml/kg; group C--placebo only; group D--ranitidine only. Gastric contents were aspirated after induction of anesthesia. Mean volume (range) in ml/kg of aspirated gastric fluid in each group was: group A--0.34 (0-1.0); group B--0.17 (0.07); group C--0.25 (0-1.1); group D--0.16 (0-0.6). The pH mean (range) value was: group A--1.83 (0.9-3.6); group B--4.76 (2.0-7.7); group C--2.10 (1.2-4.1); group D--3.97 (1.3-7.3). PSP could not be detected in the gastric samples from children in whom the ingestion-sampling interval was more than 2.25 h. In comparison with prolonged starvation, administration of oral liquids without ranitidine 2-3 h preoperatively did not produce a significant increase in mean volume of gastric aspirate, and there was no increase in the number of patients with gastric aspirate greater than 0.4 ml/kg. Administration of ranitidine with or without fluids resulted in a decrease in both volume and acidity of gastric contents.

Multicenter study of general anesthesia. I. Design and patient demography.

A prospective randomized clinical trial of enflurane, fentanyl, halothane, and isoflurane is described. The 17,201 patients were stratified into two groups (preanesthetic medication and no preanesthetic medication) and were randomized to one of four study agents: enflurane, fentanyl, halothane, and isoflurane. Fifteen university-affiliated hospitals in the United States and Canada participated. All patients were first assessed preoperatively. Data were collected during anesthesia, in the immediate recovery period, and for up to 7 days after anesthesia/surgery. The mean age of the patients was 43 yr, the mean height 167 cm, and the mean weight 68 kg. Sixty-five percent of patients were female. In this study 90.7% of patients were classified as ASA Physical Status 1 or 2, and 34.7% of patients smoked. It is concluded that pooling of data across institutions was valid and does allow determination of the efficacy and relative safety of the four study agents.

Acute transient unilateral macroglossia following use of a LMA

To the Editor: We have observed an epidural haematoma (EH) in a 64-yr-old female patient admitted for a right-knee fracture. At admission she was not receiving any medication. There was a remote history, 17 yr earlier of possible primary biliary cirrhosis. The only abnormal tests were the serum alkaline phosphatase (ALP) (407 U.L -I) and serum gamma-glutamyi transpeptidase (GGT) (168 U.L-J). Prophylaxis against deep venous thrombosis was undertaken with 5000 U calcium heparinate sc every eight hours. Coagulation status, monitored at the time of surgery, showed platelet count 128.000. ml -j, fibrinogen 397 ragdl -t, prothrombin time 100%, and activated partial thromboplastin time 30 sec. Spinal anaesthesia was performed 16 hr after the last dose of heparin using a 25-ga Quincke spinal needle at L3-4. Needle placement was easy and free flow of unstained cerebrospinal fluid was obtained at the first attempt. Postoperative medications included diclofenac sodium 75 nag im administered once. Two days later, a magnetic resonance imaging (MRI) (required due to the appearance of paraesthesiae, perineal numbness and lower extremity weakness) showed an anterior extradural haematoma from La to L4 (Figure). Laminectomy was performed and a non organized haematoma was drained. One month after surgery the patient was able to walk with the aid of a cane and her bladder paresis was recovering. The EH was located in front of the spinal cord and this uncommon site for EI-I may be linked to the small bore of the spinal needle employed. The lack of feeling during needle placement and the long delay before CSF appeared at the hub may have been the cause of unrecognized dislocation of the needle lip in the anterior area of epidural space.