Biomedical subjects
J M Gibbs
Publications and source records attributed to J M Gibbs.
Cerebral neoplastic angioendotheleosis complicated by hypercalcaemia.
This is a case report of a 67 year old man who presented with a fluctuating level of consciousness and myoclonic jerks caused in part by hypercalcaemia. The diagnosis of cerebral neoplastic angioendotheleosis was only made later on brain biopsy and is the first report of the occurrence of hypercalcaemia in neoplastic angioendotheleosis.
Cerebral blood flow, blood volume and oxygen utilization. Normal values and effect of age.
Regional cerebral blood flow (CBF), oxygen extraction ratio (OER), oxygen utilization (CMRO2) and blood volume (CBV) were measured in a group of 34 healthy volunteers (age range 22-82 yrs) using the 15O steady-state inhalation method and positron emission tomography. Between subjects CBF correlated positively with CMRO2, although the interindividual variability of the measured values was large. OER was not dependent on CMRO2, but highly negatively correlated with CBF. CBV correlated positively with CBF. When considering the values of all the regions of interest within a single subject, a strict coupling between CMRO2 and CBF, and between CBF and CBV was found, while OER was constant and independent of CBF and CMRO2. In 'pure' grey and white matter regions CMRO2, CBF and CBV decreased with age approximately 0.50% per year. In other regions the decline was less evident, most likely due to partial volume effects. OER did not change or showed a slight increase with age (maximum in the grey matter region 0.35%/yr). The results suggest diminished neuronal firing or decreased dendritic synaptic density with age.
How safe is anaesthesia in New Zealand?
Explore the source record for details and available documents.
The New Zealand scene: implications of no fault accident compensation.
Explore the source record for details and available documents.
A clinical comparison of atracurium and vecuronium in women undergoing laparoscopy.
In a double-blind, prospective, randomised trial in 30 women undergoing laparoscopy, atracurium and vecuronium were compared in equipotent (2 X ED95) doses. In the atracurium group, first twitch depression was significantly greater at one minute, and degree of fade significantly greater at one and two minutes, but thereafter neuromuscular monitoring showed no significant difference between the groups. Clinically there was no significant difference between the drugs. Mild intraoperative hypotension was equally common in both groups as was sinus bradycardia. Reversal and recovery were comparable in the two groups. Neostigmine was required in all patients and in three (one atracurium, two vecuronium) a second dose was required in all patients and in three (one atracurium, two vecuronium) a second dose was administered on clinical grounds. Antagonism of the neuromuscular block is required with surgery of this duration despite the intermediate duration of action of the relaxant drugs.
Cerebral haemodynamics in occlusive carotid-artery disease.
Explore the source record for details and available documents.
Clinical comparison of atracurium and alcuronium in gynaecological surgery.
In a double-blind, prospective, randomised trial in 51 female patients, atracurium 0.6mg/kg provided acceptable intubating conditions more rapidly than did alcuronium 0.25 mg/kg. Atracurium produced more profound neuromuscular twitch suppression than alcuronium. The effect of atracurium was longer-lasting than that of alcuronium (32 minutes and 22 minutes respectively to achieve 10% recovery) and it took slightly longer to reverse with neostigmine. Seven patients in the atracurium group who underwent short surgical procedures required supplementary neostigmine to achieve adequate reversal. Two cases of sinus bradycardia were noted in the atracurium group, but hypotension was not a clinical problem in any patient. Atracurium appears to be a useful relaxant, but a smaller dose than that used here should be chosen for short procedures.
A hospital viewpoint: what are patients for (or doctors for that matter)
Explore the source record for details and available documents.
Preservation of the pulmonary vasoconstrictor response to alveolar hypoxia during the administration of halothane to dogs.
The action of halothane on the pulmonary vasoconstrictor response to unilateral alveolar hypoxia was studied in two groups of dogs. In the first group the redistribution of blood flow between the two lungs was studied with a radioactive isotope method, which provided intermittent measurements, whilst in the second group the distribution of blood flow was observed continuously. In both groups there was no significant alteration of the hypoxic vasoconstrictor response with inspired halothane concentrations varying from 0.5 to 1.5%.
Lack of effect of morphine and buprenorphine on hypoxic pulmonary vasoconstriction in the isolated perfused cat lung and the perfused lobe of the dog lung.
In an isolated perfused cat lung preparation and a perfused lobe of dog lung preparation a pressor response of the pulmonary circulation was elicited to alveolar hypoxia (5% oxygen). The magnitude of this reponse was not affected by either of the opioid drugs, morphine or buprenorphine.
A case of rhabdomyolysis associated with suxamethonium.
A boy presenting for oesophagoscopy developed myoglobinuria during convalescence from the procedure. A susceptibility to malignant hyperpyerexia was considered in the differential diagnosis but was felt to be unlikely on the basis of in vitro testing of muscle biopsy specimens. A review of relevant papers suggests that rhabdomyolysis of significant degree following suxamethonium administration may be more common than generally appreciated, particularly in children.
Effect of buprenorphine on the ventilatory response to carbon dioxide.
Buprenorphine is a potent synthetic opioid-partial antagonist analgesic drug currently under clinical trial. When administered intravenously to human volunteers buprenorphine produced a significant depression of the ventilatory response to carbon dioxide stimulus for a period in excess of six hours.
The need to train anaesthetists in New Zealand.
A survey of New Zealand public hospitals undertaken at the end of 1974 shows that the country is training half the number of anaesthetists to maintain the public hospital-based anaesthetic services. There is a need to develop and expand training programmes for anaesthetists. New graduates can be assured that there are career prospects in the specialty.
Effect of halothane and diethyl ether on the circulatory response to carbon dioxide in the isolated perfused cat lung.
Constant flow perfusion of the pulmonary circulation was established in isolated cat lungs. These were ventilated with 5% carbon dioxide in oxygen in order to maintain a near-normal carbon dioxide tension and acid-base status in the perfusing blood. The alteration of pulmonary vascular resistance in response to a change in inspired carbon dioxide concentration from 5% to 10% was investigated before, during and after the administration of 1% halothane (in 16 perfusions) or 5% diethyl ether (in 8 perfusions). An increase of inspired carbon dioxide concentration caused a significant increase in pulmonary vascular resistance, but the magnitude of the increase was diminished during the administration of both anaesthetic agents. The response increased again after the anaesthetics were withdrawn. The administration of halothane during ventilation with 5% carbon dioxide caused a significant reduction of pulmonary vascular resistance whilst diethyl ether resulted in a significant increase in this measurement. It is suggested that inhalation anaesthetic agents may increase ventilation/perfusion mismatching by altering the normal vasoconstrictor response to increased alveolar PCO2;
The cardiovascular effects of pancuronium in the dog during pentobarbitone anaesthesia.
The effect of pancuronium on the cardiovascular system of the dog was studied in 12 greyhounds who were anaesthetized with pentobarbitone 30--40 mg/kg body weight. During the study, the animals were artificially ventilated to give an end-tidal carbon dioxide in the range 4-0--4-5 per cent. Duplicate cardiac output measurements were made before and ten minutes after the intravenous administration of pancuronium (0-18 mg/kg). There was a slight (but statistically insignificant) fall in cardiac output. Heart rate, aortic and pulmonary arterial pressures remained substantially unaltered. It is suggested that pancuronium should be used in the dog when muscle relaxation is required during pentobarbitone anaesthesia. In this way cardiovascular changes related to the drugs themselves will be minimized.
Thrombin-induced disseminated intravascular coagulation. III:Modification by dextran infusion.
The cardiorespiratory effects of thrombin-induced disseminated intravascular coagulation (DIC) were studied in two groups of dogs. The main changes were a reduction in cardiac output and arterial pressure, an increase in pulmonary artery pressure and, an increase in pulmonary artery pressure and an increase in venous admixture. In one group of dogs the reduction in cardiac output was diminished by the infusion of dextran 35 ml/kg body weight. This resulted in an increased pulmonary artery pressure but no significant differences in the indices of the efficiency of gas exchange. However, the haemodilution resulted in a lower mixed venous and arterial PO2 in this group of dogs.