Minimum oxygen requirements during anaesthesia with the Triservice anaesthetic apparatus A study of drawover anaesthesia in the young adult

Thirty-six servicemen were anaesthetised using the Triservice anaesthetic apparatus. They were allocated randomly into one of two groups, to breathe spontaneously or to receive artificial ventilation, and into subgroups who were given air alone, or air supplemented with 1 or 4 litres/minute of oxygen. A further 12 subjects were studied subsequently using 0.5 litres/minute of added oxygen. Intra-operative blood gases were compared with those of awake premedicated controls. Artificial ventilation was associated with an unchanged arterial oxygen tension with air alone; in the other subgroups arterial oxygen tension was higher than with spontaneous respiration when related to inspired oxygen fraction (p less than 0.05). Air anaesthesia caused significant hypoxaemia with spontaneous ventilation (p less than 0.05), and 50% of the subjects required assisted ventilation. There was also a significant respiratory acidosis (p less than 0.05). Intermittent positive pressure ventilation is the method of choice for field anaesthesia when oxygen is unavailable. Spontaneous respiration must be supplemented with at least 0.5 litres minute of oxygen.     

Phenelzine poisoning

A 46-year-old female with severe phenelzine poisoning was managed successfully by alpha blockade and fluid loading, with the aid of invasive haemodynamic monitoring. The pathophysiology was documented, showing elevated plasma and urinary catecholamines, cardiovascular abnormalities and a contracted blood volume. Most of these changes were reversed following treatment.     

Ovarian Ectopic Pregnancy—A Diagnostic Dilemma

A recent case of ovarian pregnancy, the diagnosis of which is often retrospective, is presented. The discussion is based on current literature concerning the diagnostic difficulties associated with this condition.     

Papaveretum infusions in infants under 6 months of age

The effectiveness of a continuous low dose papaveretum infusion for the relief of postoperative pain was assessed in 29 infants aged 1-6 months nursed on the infant surgical ward following major abdominal surgery. Trained nursing staff were able to adjust the dosage within prescribed guidelines and satisfactory analgesia was obtained with a regimen which delivered up to 0.0375 mg/kg/hour, approximately half the dose recommended in children older than 12 months. There was one case of clinically significant respiratory depression.     

Day case laparoscopy: a survey of postoperative pain and an assessment of the value of diclofenac

A randomised, controlled study was undertaken to assess the postoperative pain and side effects experienced by patients undergoing day case diagnostic laparoscopy and laparoscopic sterilisation, and to evaluate the effectiveness in these patients of peroperative diclofenac. Patients undergoing laparoscopic sterilisation had significantly higher pain scores at one hour postoperatively, and at discharge, than patients undergoing diagnostic laparoscopy (p less than 0.01) but there were no significant differences in pain scores 24 hours after discharge. The incidence of postoperative side effects following discharge from hospital was high, but there were no significant differences between the groups. Diclofenac had no significant effect in either group on the severity of postoperative pain, or the incidence of postoperative side effects.     

Calcium gradients in inner ear endolymph

Recent studies suggest that endolymphatic hydrops resulting from the ablation of the endolymphatic duct and sac in guinea pigs may be caused by a disturbance of endolymph calcium homeostasis. A similar disturbance of calcium homeostasis could represent the underlying cause of Ménière's disease. In this study, we mapped the calcium concentrations and electrical potentials throughout the endolymphatic system in normal guinea pigs. Large concentration differences exist between different compartments, including a more than twofold increase along the length of the cochlea. The electrochemical potential for calcium (the force driving passive longitudinal calcium movement) was calculated for all the endolymphatic compartments. The results show that endolymph is extremely inhomogenous with respect to calcium potentials. On the basis of these potentials, it appears that calcium is transported into endolymph in the cochlea and out of endolymph in the saccule and utricle. The possibility that endolymphatic hydrops arises from a disturbance in longitudinal flow of calcium, rather than in longitudinal volume flow, is considered.     

Maxillofacial trauma in severely injured patients

A study was made of maxillofacial trauma in seriously injured patients to determine the likely role of oral and maxillofacial surgeons working in the regional trauma centres proposed by the Royal College of Surgeons of England. There were 153 patients, aged 70 years or less, who sustained major trauma (injury severity score 16 or more) and were admitted directly to the accident departments of the Bristol Royal Infirmary or Derriford Hospital, Plymouth during 1989. Maxillofacial injuries occurred in 50 (33%) of these patients with lacerations present in 39, burns in 1 and facial bone fractures in 28 (18%); soft tissue abrasions and contusions were excluded. The aetiology, patterns of injury, surgical treatment and outcome were reviewed. The implications for the provision of maxillofacial surgical services in regional trauma centres is discussed.     

Hepatic artery aneurysm in corticosteroidtreated,adult Kawasaki's disease

We describe a single case of Kawasaki's disease (mucocutaneous lymph node syndrome) with the rare complication of a hepatic artery aneurysm which was surgically repaired. Unusual features include arterial aneurysmal formation in the hepatic arteries rather than in coronary arteries, the unusual morphology of the hepatic artery aneurysm, and the expansion of the aneurysm after corticosteroid therapy.     

De novo generation of histamine in sputum and the effect of antibiotics

We have performed experiments to test the hypothesis that bacteria may contribute to the presence of histamine in sputum. Sputum samples obtained from 7 patients with exacerbations of chronic bronchitis and 7 patients with cystic fibrosis were incubated at 37°C for 72 hours. Serial sputum histamine estimations, performed by a recently-developed HPLC technique, showed large, progressive increases in both groups of samples. Both the pre-heating of samples at 100°C prior to incubation and the addition of antibiotics to the incubates substantially reduced these increases. These findings strongly suggest that bacteria may contribute to sputum histamine in infective lung disease.     

Isoflurane for anaesthesia in the dental chair. A comparison of the incidence of cardiac dysrhythmias during anaesthesia with halothane and isoflurane

A randomised single-blind trial was performed to compare the effects on cardiac rhythm of isoflurane and halothane in 100 dental outpatients having extractions under general anaesthesia in the dental chair without tracheal intubation. The incidence of supraventricular dysrhythmias did not differ significantly. No patient in the isoflurane group developed a ventricular dysrhythmia, whilst nine of those who received halothane did so (p = 0.0013). The quality of anaesthesia was acceptable in the isoflurane group, but induction time was longer (p less than 0.05) and the maximum heart rate was faster (p less than 0.01). There was no difference in the maximum end tidal carbon dioxide concentrations measured in a further 20 cases.