Search PubMed⌕ Search

Biomedical subjects

G M Hall

Publications and source records attributed to G M Hall.

At least 181 records · Page 10Linked to original sources
PubMed1980

Beta-adrenergic blockade and the metabolic response to surgery.

The effect of the administration of propranolol 0.15 mg per kg body weight i.v. on the metabolic response to pelvic surgery was compared with results in similar patients who had not received propranolol. The only significant difference between the two groups was a lower plasma insulin concentration in the beta-blockade patients after 60 and 90 min of surgery. The glycaemic response to surgery was unimpaired in the propranolol-treated patients and there were no adverse haemodynamic effects. We conclude that beta-adrenergic blockage is unlikely to have deleterious metabolic effects on healthy patients.

Adult↗
PubMed1979

Epidural analgesia and the metabolic response to surgery.

The effect of epidural blockade on the metabolic and hormonal responses to pelvic surgery was investigated in 14 female patients. Central venous blood samples were collected every 30 minutes and analysed for free fatty acids, glycerol, beta-hydroxybutyrate, acetoacetate, glucose, lactate, pyruvate, cortisol and growth hormone concentrations. There was no change in fat and glucose metabolism except for a transient decrease in lipolysis after 30 minutes of surgery. Cortisol and growth hormone values were significantly increased (p less than 0.01) after 60 minutes. A small but statistically significant increase in blood lactate concentration was observed (p less than 0.01) and the concept of a "metabolic V/Q" abnormality is postulated to explain the lacticacidaemia.

Adult↗
PubMed1979

Oxygen transport during dopamine infusion in dogs.

Catecholamines increase not only oxygen delivery to tissues but also oxygen consumption (VO2). The effect of an infusion of dopamine hydrochloride has been studied at two doses, each in six dogs. Dopamine 10 micrograms kg-1 min-1 caused an increase in haemoglobin concentration and altered cardiac output, oxygen availability and total body oxygen consumption such that oxygen availability ratio increased and (CaO2-CVO2) decreased although these changes were not statistically significant. Dopamine 30 micrograms kg-1 min-1 increased (P less than 0.05) heart rate, haemoglobin concentration and CaO2 and significantly reduced stroke volume and VD/VT. Although oxygen availability increased, increases in oxygen consumption were greater and this resulted in a statistically insignificant reduction in oxygen availability ratio and an increase in (CaO2-CVO2). Terminating the dopamine infusion resulted in significant (P less than 0.05) decreases in cardiac output, PVO2, CaO2), oxygen availability and oxygen consumption and an increase in (CaO2-CVO2). It was concluded that maximum oxygen delivery occurs at a lower dose than that required to produce the maximum increase in oxygen consumption.

Animals↗
PubMed1979

Metabolic changes during dopamine infusion in dogs.

The effects were investigated, in 12 dogs, of the infusion of dopamine 10 or 30 micrograms kg-1 min-1 on circulating glucose, glycerol, lactate and potassium concentrations. Both doses of dopamine produced in initial increase in blood glucose concentration (P less than 0.05) followed by hypoglycaemia (P less than 0.05). Lipolysis was stimulated as shown by an increase in plasma glycerol concentrations with dopamine 10 micrograms kg-1 min-1 (P less than 0.05) and dopamine 3 micrograms kg-1 min-1 (P less than 0.01). Blood lactate concentrations increased slightly in both groups, but this was significant (P less than 0.05) only in the dogs infused with dopamine 10 micrograms kg-1 min-1. Dopamine had no significant effect on the plasma potassium concentration.

Animals↗
PubMed1979

Redistribution of body heat during anaesthesia. A comparison of halothane, fentanyl and epidural anaesthesia.

Epidural anaesthesia and high dose fentanyl (50 micrograms/kg) when used to supplement nitrous oxide and oxygen anaesthesia for a standard lower abdominal operation were associated with a mean fall in deep body temperature, as measured in the external auditory meatus, of 0.46 degrees C and 0.6 degrees C/hr respectively. This is significantly different from the mean values of 0.14 degrees C and 0.2 degrees C/hr which were recorded when moderate dose fentanyl (10 micrograms/kg) or 0.5% halothane were used to supplement anaesthesia. When mean skin temperature is combined with the core temperature to provide an estimate for total body heat, there is no difference between the groups. Redistribution of body heat occurs and this may be related to reduced adrenergic stimulation and altered regional blood flow. Where the facilities and environments are inadequate for the maintenance of normothermia, care should be taken in the choice of anaesthetic technique. In the recovery period mean body heat gain showed a wide scatter of results but those patients receiving epidural anaesthesia were slow to rewarm despite a high incidence of shivering in this group. The implications of this are discussed.

Adult↗
PubMed1979

Porcine heterograft dressings for split-thickness graft donor sites.

As compared with previous methods of donor site care, procine heterograft dressings allow the donor site to heal faster, require less postoperative care, are associated with a lower infection rate and eliminate virtually all of the pain of the split-thickness wound. Our experience supports that of others. We believe our modifications of this technique to be superior to previous modalities of donor site care.

Bandages↗
PubMed1978

Biochemical changes in horses during a 50-mile endurance ride.

Blood samples were taken from 15 horses before and after a 50-mile ride to examine the changes occurring in some biochemical constituents. There was a significant (P less than 0.05) decrease in plasma potassium, calcium and magnesium concentrations and a rise in inorganic phosphate but there was no alteration in plasma sodium, chloride or protein levels or change in haematocrit. After the ride there was a highly significant (P less than 0.01) fall in blood glucose corresponding with increased lipolysis and a rise in plasma free fatty acids (P less than 0.001) and glycerol (P less than 0.001). There was a modest increase in blood lactate and a rise in plasma creatine phosphokinase. The results of this preliminary investigation are discussed in relation to the problem of exhaustion in horses during endurance rides.

Animals↗
PubMed1978

Heat loss during anaesthesia.

The superficial and deep body temperatures of 23 patients were studied during prolonged anaesthesia for microscopic surgery of the fallopian tubes. The patients were divided randomly into three groups, receiving either halothane 0.5%, halothane 1% or low-dose fentanyl as a supplement to nitrous oxide, oxygen and myoneural block. Other variables were kept constant, and the theatre temperature was maintained at 24 degrees C. Temperature changes were unrelated to both the type of anaesthesia and the percentage of subcutaneous fat to body weight. Halothane 1% decreased the rate of heat loss in the 3rd hour. Large heat losses occurred on transfer to the recovery room, where the total heat produced increased rapidly and was unrelated to shivering.

Adult↗
PubMed1978

Porcine malignant hyperthermia. VI: the effects of bilateral adrenalectomy and pretreatment with bretylium on the halothane-induced response.

The effects of bilateral adrenalectomy, together with the i.v. administration of bretylium tosylate 20 mg kg-1 on halothane-induced malignant hyperthermia (MH), were investigated in six Pietrain pigs. All six animals survived the halothane challenge, and failed to show any signs of increased muscle metabolism. Bilateral adrenalectomy alone prevented halothane-induced MH in three out of four Pietrain pigs, whereas the i.v. administration of bretylium alone protected only one pig out of an additional four animals studied. The results show that complete adrenergic blockade inhibits the susceptibility of Pietrain skeletal muscle to halothane and that the adrenal medulla makes an important contribution to this response.

Adrenalectomy↗
PubMed1978

Plasmapheresis and plasma cholinesterase.

Plasma cholinesterase (E.C. 3.1.1.8) concentrations were measured in nine outpatients who were undergoing regular plasmapheresis. A single plasmapheresis produced a 64% reduction in cholinesterase concentration compared with the value before plasmaphersis. Another patient who received four plasma exchanges in 6 days showed a progressive reduction in cholinesterase concentration to only 8% of the initial value. It is suggested that drugs metabolized by cholinesterase should be used with caution in patients undergoing plasmapheresis, particularly when frequent plasma exchanges are undertaken.

Adolescent↗