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Biomedical subjects

N R Webster

Publications and source records attributed to N R Webster.

106 records · Page 6Linked to original sources
PubMed1989

The laryngeal mask airway. A study of 100 patients during spontaneous breathing.

A prototype size 3 laryngeal mask was used in 100 patients by 18 anaesthetists with no previous experience of its use. A clear and unobstructed airway was obtained in 98% of patients, without requiring support of the jaw, thus leaving the anaesthetists' hands entirely free. The patency of the airway did not deteriorate during the course of the anaesthetic. In 10 patients there was obstruction of the airway at the first attempt to place it without the introducer and this obstruction appeared to be as a result of downfolding of the epiglottis. Subsequent attempts at passage were successful in all 10 patients. The seal between the mask and the larynx was adequate for artificial ventilation of the patients, but the mean leak pressure was 1.7 kPa.

Anesthesia↗
PubMed1988

Adult respiratory distress syndrome--how many cases in the UK?

Previously reported figures for the incidence of Adult Respiratory Distress Syndrome, based largely on American results, would suggest that the average British Health District of 200,000 people could expect to see 130 cases per year. This figure is greatly in excess of that expected from our clinical experience. We have undertaken a retrospective survey of patients within a British Health Region (population, 3,599,400). Results indicate an incidence of nine for an average Health District of 200,000 population, or 2.5% of all admissions to intensive therapy units, or 0.045 per 1000 resident population.

Adult↗
PubMed1987

Inorganic phosphate transport across the red blood cell membrane: the effect of exposure to hyperoxia.

Red cell structure and function were examined in rats exposed to 80% oxygen: 20% nitrogen for five days and compared with red cells from air-breathing animals. Evidence of red cell destruction was noted in the animals exposed to hyperoxia. Osmotic fragility was found to be reduced in red cells from oxygen exposed rats (p less than 0.05), also, red cell haemolysis in hydrogen peroxide was noted to be greater (p less than 0.001) in these animals. Inorganic phosphate ion transport was significantly reduced (p less than 0.001) in the red cells from rats receiving oxygen for 5 days. The results demonstrate a decreased ability of the red cell to transport anions and suggest an impairment of the normal movement of water across the membrane following exposure to oxygen.

Animals↗
PubMed1987

Tissue responses to hyperoxia. Biochemistry and pathology.

An animal model was established to study the toxic effects of hyperoxia and the consequent changes in intracellular antioxidant status. Superoxide dismutase, catalase and glutathione peroxidase activities were measured in erythrocytes, liver and lung, in addition to cellular glutathione concentrations and its associated metabolism. Overt cellular damage was assessed biochemically by measurement of lipid peroxidation, hydrogen peroxide-induced haemolysis and osmotic fragility. Pathological changes were assessed by light and electron microscopy. Up to 11 days exposure of rats to 80% oxygen was not lethal, but resulted in overt cellular damage to red blood cells (haemoglobin concentration decreased from 13.8 +/- 1.4 (SD) g dl-1 to 12.4 +/- 0.5 g dl-1; hydrogen peroxide-induced haemolysis increased from 7.7 +/- 1.6% to 75.1 +/- 13.5% after 11 days of hyperoxia) and to cells of lung (4-fold increase in lipid peroxidation) as well as a biochemical adaptation to the increased concentration of oxygen metabolites (superoxide dismutase increased 3-fold, catalase 5-fold and glutathione peroxidase 2-fold). It is suggested that red cell hydrogen peroxide-induced haemolysis and reduced glutathione concentration may be useful indicators of oxidant stress in the clinical situation.

Animals↗
PubMed1987

Closed-loop administration of atracurium. Steady-state neuromuscular blockade during surgery using a computer controlled closed-loop atracurium infusion.

The advent of newer muscle relaxants with predictable rates of metabolism and times of offset of neuromuscular blockade now makes it possible to use intravenous infusion safely as a mode of delivery. This has many advantages over administration by intermittent bolus. Moreover, it is feasible to use a servo system for their delivery. We have developed and evaluated such a system which is portable and requires little computer expertise to set up and use. It is a useful adjunct to routine anaesthesia, as well as a potentially powerful research tool.

Adolescent↗
PubMed1986

Sleep and comfort after caesarean section.

To compare postoperative well-being after general and epidural anaesthesia, 58 women undergoing Caesarean section were divided into a general anaesthetic group receiving intramuscular opioid postoperatively (26), and an epidural group receiving morphine via the epidural route (32). The epidural group required less analgesia (p less than 0.01 at 0.5 and 8 hours, p less than 0.001 at 4 hours). There was no difference in the use of oral analgesics. At 1, 4 and 24 hours after delivery more patients in the general anaesthesia group described themselves as very comfortable (p less than 0.05). More in the epidural group had a very good night's sleep during each night studied. Patients in the epidural group were slower to use the ward toilet (p less than 0.01) and had more itching (p less than 0.001). Our conclusion is that patients progressed well in both groups.

Adolescent↗
PubMed1986

Topical adrenaline.

Explore the source record for details and available documents.

Administration, Topical↗
PubMed1986

Effects of blood storage on red cell antioxidative systems.

The activities of the antioxidative enzymes superoxide dismutase, catalase and glutathione peroxidase and the concentration of reduced glutathione were determined in CPD-adenine blood stored at 4 degrees C for up to 20 days. Superoxide dismutase activity was found to be significantly reduced with storage beyond 10 days. The clinical significance of this finding is discussed.

Blood Specimen Collection↗
PubMed1979

Adverse reaction to disopyramide.

A case is reported where the use of i.v. disopyramide for a supraventricular tachycardia resulted in a more serious ventricular dysrhythmia giving hypotension and this probably contributed to the development of a myocardial infarction. Attention is drawn to the possible risk.

Arrhythmias, Cardiac↗
PubMedDate not supplied

Inotropic agents in the critically ill.

Inotropic agents are commonly used in critically ill patients. This heterogeneous group of drugs are potentially hazardous if used without a good understanding of cardiovascular physiology and pathophysiology and without due attention to some general principles for their use. We suggest guidelines for the administration of these agents in all clinical settings.

Cardiotonic Agents↗
PubMedDate not supplied

Nitric oxide in critical care medicine.

Few areas of medicine have failed to be affected by the discovery of nitric oxide and the unravelling of its many physiological and pathophysiological roles. Possibly no other area of medicine has this discovery had so many potential therapeutic applications as in the field of critical care medicine. But will this widespread interest in nitric oxide result in the promised revolution in clinical care?

Administration, Inhalation↗