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Biomedical subjects

R G Hicks

Publications and source records attributed to R G Hicks.

At least 37 records · Page 2Linked to original sources
PubMed1988

Combined carotid and coronary artery surgery: a review of the literature.

This article reviews 41 different reports that describe various means of surgical management of coexistent carotid and coronary artery disease in almost 1,500 patients. Stroke is the major risk for patients undergoing myocardial revascularization in the presence of symptomatic carotid artery disease or an asymptomatic carotid bruit that reflects an ulcerative lesion or stenosis exceeding 75%. However, patients with asymptomatic carotid stenosis should not routinely undergo prophylactic carotid endarterectomy. Myocardial infarction is the major hazard in patients undergoing carotid endarterectomy who have coronary artery disease. This risk is magnified when the disease is silent. A high level of awareness and rigorous screening are essential in all patients suspected of having coexistent disease. Although a protocol for the management of these patients is important, individual assessment is essential.

Carotid Artery Diseases↗
PubMed1986

Operative mortality after coronary artery surgery. A seven-year experience of 1500 consecutive operations.

Between January 1978 and August 1985, 1500 patients underwent coronary artery bypass grafting by one surgical team, with a total mortality of 0.46% (seven patients). All these patients were suffering from class 3 or class 4 angina and more than half (54%) had evidence of preoperative infarction. The achievement of minimal mortality and morbidity is the immediate aim of surgery; a continuing long-term improvement in symptoms and life expectancy is the ultimate goal. Every physician should be aware of the risks of the invasive treatment of coronary artery disease either by bypass grafting or by angioplasty.

Adult↗
PubMed1986

Thiopentone cerebral protection under EEG control during carotid endarterectomy.

Seventy patients who underwent a total of 77 consecutive carotid endarterectomies were given thiopentone (mean dose 19 mg/kg) under EEG control for cerebral protection during the period of carotid clamping. This technique was used instead of elective insertion of a temporary bypass shunt in response to adverse EEG changes occurring after clamping. The EEG was monitored continuously throughout operation. The EEG burst-suppression pattern with electrically inactive periods of 30-60 seconds was taken as indicating a depth of barbiturate anaesthesia adequate to provide brain protection. Patients exhibited a drop in blood pressure during barbiturate administration: in most the pressure recovered spontaneously but in twenty operations metaraminol was needed to re-establish an adequate pressure before clamping. No adverse cardiological effects were associated with the administration of thiopentone or metaraminol. There was no mortality and no neurological morbidity in this series.

Aged↗
PubMed1981

Gas chromatographic--mass spectrometric detection of circulating plasticizers in surgical patients.

Gas chromatographic and gas chromatographic--mass spectrometric analytical techniques were employed to quantitate and confirm levels of circulating organic plasticizers in critically ill surgical patients. Two plasticizers, dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), have been identified. DEHP can be found in many plastic medical devices. The DEHP levels were significant soon after transfusion or in the presence of renal dysfunction. The source of DBP is not clear at present and requires further study. The prevention of this contamination and the toxicity of these plasticizers should be investigated to ensure the safe use of plastic medical devices.

Critical Care↗
PubMed1981

Electroencephalographic changes with hypothermia and cardiopulmonary bypass in children.

Our experience of EEG changes associated with hypothermia, induced predominantly by core cooling, is presented. Easily recognizable, repeatable patterns emerge and four different types of changes are seen, from generalized slowing and loss of faster rhythms progressing to discontinuous activity, burst suppression activity, and finally loss of all cerebral potentials. These patterns were not altered significantly by anesthetic agents or by patient age or weight differences. Abnormalities of various kinds can be distinguished from the hypothermic changes. In particular, continuous epileptiform activity can be recognized and therefore abolished.

Adolescent↗
PubMed1980

Asymptomatic aneurysm of the extracranial internal carotid artery: report of a case.

A rare case of saccular aneurysm of the right internal carotid artery is presented. The patient was asymptomatic, and the aneurysm was discovered incidentally at examination after a fall. The diagnosis was confirmed angiographically, and the aneurysm was surgically excised with end-to-end anastomosis of the artery.

Carotid Artery Diseases↗
PubMed1980

The effects of althesin on the electroencephalograph.

The EEG was continuously recorded on 43 patients who received Althesin. A basic pattern for this drug, typical of most general anaesthetic agents at a level of light surgical anaesthesia, was established. Four significant levels of change could be discriminated in the EEG following administration of incremental boluses of undiluted Althesin, reflecting deeper levels of anaesthesia. These ranged from a mild slowing of the dominant rhythms to burst-suppression activity at the deepest level reached with larger doses. The EEG demonstrated that althesin has a rapid onset and a short duration and that recovery is rapid and complete after continuous infusion.

Adolescent↗
PubMed1979

The vestibulo-ocular (caloric) reflex in the diagnosis of cerebral death.

Correlation between vestibulo-ocular (caloric) reflex and the electroencephalogram was examined in 25 apparently brain-dead and 17 severely brain-injured patients. Among the apparently cerebrally dead, 3 patients still had some EEG activity and in 2, there was some response to caloric testing. In the control group of patients some EEG activity was present in all, and the caloric response was absent in 1. It is concluded that absence of caloric response has similar power to the electroencephalogram in confirming cerebral death. The diagnosis, however, must be made on the total information available, including history and examination of the patient. The policy of the Intensive Care Unit of Prince Henry Hospital in this regard is outlined.

Brain Death↗
PubMed1979

Case report: althesin in status epilepticus.

A case of status epilepticus, resistant to conventional anti-epileptic treatment is described. Althesin rapidly abolished the epileptic activity, and control was achieved by a continuous infusion of Althesin.

Aged↗
PubMed1979

Deep hypothermic arrest: observations on later development in children.

Thirty-two children were reviewed following closure of ventricular septal defect in infancy. Fifteen had undergone continuous perfusion and 17 had been subjected to core cooling followed by deep hypothermic arrest. Parental and professional evaluations of intellectual and motor development, at periods between 7 and 72 months following operation, suggest that there is a higher incidence of developmental abnormality in the subgroup treated with deep hypothermic arrest.

Cardiopulmonary Bypass↗
PubMed1976

The influence of duration of circulatory arrest at 20 degrees C on cerebral changes.

In infants and piglets subjected to periods of circulatory arrest at 20 degrees C there was close correlation between duration of arrest and delay in return of electroencephalographic activity. Post mortem studies demonstrated histological evidence of brain damage in patients after circulatory arrest at 20 degrees C. Similar histological changes were demonstrated in piglets, including some who had complete E.E.G. and clinical recovery from circulatory arrest.

Animals↗
PubMed1975

Some advantages of the membrane oxygenator for open-heart surgery.

The Lande'-Edwards oxygenator has been used for clinical perfusions on 283 patients. Among these patients we have encountered the full range of congenital and acquired defects and a variance in age from 1 day to adulthood. Data are presented concerning the means and methods of perfusion, the defects involved, and the results of treatment. A comparison has been made between two groups of 20 adults each, one group perfused with a bubble oxygenator (Bently) and the other with the Lande'-Edwards membrane lung. This study showed that platelet function is better preserved by the membrane lung, that hemolysis is less severe, and that postoperative bleeding is reduced. Indirect evidence has been accumulated to suggest that pulmonary, cerebral, and renal function is also better preserved when the membrane lung is employed.

Adolescent↗
PubMed1975

The surgical management of extracranial cerebrovascular occlusive disease: a review of 200 consecutive surgical cases.

The role of surgery in the treatment of extracranial cerebrovascular disease is essentially a prophylactic one but it should be borne in mind that apart from preventing stroke, such procedures will or should eliminate symptoms. The authors believe that every patient suffering from cerebrovascular insufficiency should be thoroughly evaluated for extracranial cerebrovascular occlusive disease and that arteriograms should be performed on all patients who could be expected to be candidates for surgery. The various indications for surgery have been discussed. The authors believe that people who have severe bilateral disease and who are of an advanced age are probably in a higher risk group. They also believe that surgery should not be offered to people who have a complete stroke and who are in semi-coma or coma, no matter how rapidly they may be transferred to the operating theatre. The authors firmly believe that intra-operative E.E.G. monitoring is an important adjunct to the safe surgical treatment of lesions of the carotid bifurcation, not only to indicate when shunting is necessary but also to indicate how well that shunt is functioning. In spite of the frequent presence of associated heart disease, hypertension and other vascular lesions, operation can be offered with confidence to suitable candidates. Elimination of symptoms can be expected in over 90% of cases. Only one patient has suffered a stroke since leaving hospital and this occurred because of occlusion in his internal carotid artery which was not operated on. Apart from patient selection, the factors which have contributed to the authors' low morbidity and mortality have been the use of intra-operative E.E.G. monitoring, intra-operative heparinisation and the availability of excellent angiographic studies.

Aged↗