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Biomedical subjects

E A Moffitt

Publications and source records attributed to E A Moffitt.

At least 37 records · Page 2Linked to original sources
PubMed1979

Inline blood gas analysis by gas chromatography in patients during and after coronary artery surgery.

A system was evaluated of measuring Pao2 and Pao2 by an inline sensor in the brachial artery and gas chromatography. Eight patients having coronary artery vein grafts were studied during anaesthesia, operation, perfusion and for 24 hours afterward. Compared to conventional blood gas analysis by polarography (electrodes), the chromatographic method gave readings for Pao2 which were not significantly different during normothermia. During hypothermic perfusion, the chromatographic system read significantly higher than the bench electrode, due at least in part to a difference in temperature correction. For Pao2 the correlation between the two methods was close and differences were clinically insignificant. The Sentorr blood-gas analyser provides a sensitive, accurate indicator of changes in oxygenation, ventilation and circulation during anaesthesia and in the intensive care unit.

Anesthesia, Inhalation↗
PubMed1979

Does pulsatile flow influence the incidence of postoperative hypertension?

Twenty patients undergoing primary elective aorta--coronary artery bypass were divided into two equal groups, both receiving identical premedication, anesthetic, and pump primes. The control patients received hypothermic nonpulsatile flow and the study patients received hypothermic pulsatile flow. Hypertension, defined as a pressure of 160/100 mm Hg or higher, was observed in 80% of the control patients and 20% of the patients receiving pulsatile flow (p less than 0.05). Serial renin measurements demonstrated maximum values in the intensive care unit and coincided with the onset of postoperative hypertension in the control patients. Those patients who had received pulsatile flow did not demonstrate notable renin stimulation. Catecholamines were markedly elevated during bypass and in the intensive care unit, but there was no significant difference between the two groups. Peripheral vascular resistance was not significantly lower with pulsatile flow, except in the first study performed in the intensive care unit. We conclude that catecholamines and the renin-angiotensin system contribute to the production of postoperative hypertension and that pulsatile flow diminishes renin stimulation. Pulsatile flow results in a decreased incidence of postoperative hypertension.

Cardiopulmonary Bypass↗
PubMed1979

Aortocoronary bypass for critical stenosis of the left main coronary artery.

Over a 2-year period 33 patients with symptomatic stenosis (greater than 75%) of the left main coronary artery underwent aortocoronary bypass. Intra-aortic balloon counterpulsation was used preoperatively in only two patients as a therapeutic measure for medically unstable angina. There were no operative deaths. Follow-up study 3 to 27 months (mean 13.3 months) after operation revealed one death. Twenty-two patients were free of pain. The authors conclude that aortocoronary bypass surgery for severe stenosis of the left main coronary artery can be safely accomplished, without prophylactic use of intra-aortic balloon counterpulsation in the majority of cases, with an acceptable operative mortality and morbidity.

Adult↗
PubMed1978

Preoperative evaluation of the patient with myocardial disease: clinical review.

The patient with chronic disease of the myocardium must be evaluated perceptively as to the extent of abnormal function. The degree of reduction of cardiac reserve must be estimated and all efforts must be made to improve cardiac performance before operation; then a carefully managed anaesthetic is needed to assure a smooth operative and post-operative course.

Anesthesia↗
PubMed1978

Anaesthetic management for coronary artery bypass surgery.

The principles and practice of aneasthesia for patients having coronary bypass grafts are discussed. The essential basic principle is to restrict myocardial oxygen requirement while maintaining oxygen supply. The pathophysiology of coronary artery disease and the pharmacological principles for successful management of the cardiac patient through operation and whole body perfusion for coronary bypass grafts are summarized.

Anesthesia↗
PubMed1978

Major issues facing academic departments of anaesthesia in Canada.

Two conditions must be present for a successful and strong department: (1) the utilization of operating rooms must be efficient, patient volume must be adequate and turnover rate be rapid, if the clinical income of academic staff is to be equal to that of nonacademic anaesthetists. This is really difficult with the surgical teaching that takes place in teaching hospital operating rooms. But if university hospital operating rooms are not comparably efficient, clinical incomes for academic anaesthetists are not competitive to private practice. (2) the university (i.e. the provincial government) must pay staff adequately for their academic time so that high-grade people will accept and stay in academic posts. Part-time staff deserve to be remunerated for their contributions, whatever the magnitude, or motivation to do it is minimal. If these basic criteria of financing a department are fulfilled, development of the academic functions will follow. Strong academic departments will be producing the capable anaesthetists to fulfill the manpower needs of our specialty in Canada. If not, more departments will atrophy and the manpower situation for anaesthetists in Canada will be in an acute crisis.

Anesthesiology↗
PubMed1977

A comparative study of peripherally inserted silicone catheters for parenteral nutrition.

One hundred patients receiving parenteral nutrition with lipids and hypertonic amino acids and glucose were divided into five groups of 20, depending on the type of intravenous catheter used for the infusion. Least satisfactory were the short Butterfly needles (average 3.3 days in place) and the long peripherally inserted polyvinyl central venous catheters (average 6.2 days in place). Subclavian catheters of polyvinyl (average 15.3 days) or silicone elastomer (average 17.5 days) were equally efficacious. A new long silicone elastomer catheter inserted peripherally was most satisfactory (average 29.5 days). Problems common with polyvinyl catheters (phlebitis, thrombosis, and sepsis) rarely occurred with either the long or short silicone elastomer catheter.

Catheterization↗
PubMed1977

Anesthesia and postoperative care for cardiac operations.

Almost three decades have passed since the establishment of open-heart surgery, and in such a short life span the specialty has established itself scientifically and reached a certain maturity. New techniques, better understanding of the pathophysiology of cardiac problems, and the effective use of new drugs constantly improve the results of operation. Greater experience in anesthetic management and improved postoperative care will contribute much to the success of this youngest surgical specialty. This review outlines the current principles of anesthesia and postoperative care of patients undergoing cardiac operations. Preanesthetic evaluation provides guidance for anesthetic management, supportive techniques, and postoperative care. During operations, light anesthesia is usually sufficient for patients with cardiac disease and minimizes myocardial depression. Monitoring must provide data on the physiological changes that are taking place from moment to moment during and after operations. Perfusion produces a highly abnormal state, and the severity of complications varies with its duration. Introduction of new drugs has also facilitated hemodynamic management during and after operations. Postoperative care is based on careful observation of the patient and early detection of trends, both of which lead to preventive rather than curative treatment wheneven possible.

Anesthesia, General↗
PubMed1976

Patterns of total and ionized calcium and other electrolytes in plasma during and after general surgery.

Thirteen patients were studied during two hours of anaesthesia for abdmonial operations and for an hour post-operatively. Serial venous blood samples were taken for determination of plasma total and ionized calcium, acid-base variables, Na, K, Mg, PO4 total proteins and parathyroid hormone. One group of patients received 5 per cent dextrose/water and the other 5 per cent dextrose in Ringer's solution, at 250 ml per hour. Total and ionized calcium levels decreased toward the end of operation and an hour later, associated with respiratory alkalosis. Parathyroid hormone increased at the end of operation, as an effect of the decreased ionized calcium. The general effect was mild haemodilution with all the other electrolytes decreasing, as did total protein concentration.

Adult↗
PubMed1976

Plasma ionic calcium levels following injection of chloride, gluconate, and gluceptate salts of calcium.

The ionic equivalency of three calcium salts was tested in 15 patients undergoing cardiac surgery with extracorporeal circulation. Of the three salts tested (chloride, gluconate, gluceptate), only calcium chloride showed a reproducible and highly significant relationship between the increase in total calcium and the increase in ionic calcium. It is suggested that extracorporeal circulation may be one clinical situation in which use of a calcium electrode may be of major value. The marked distortion of plasma proteins and pH, the addition of large amounts of citrate, and the differences between various calcium salts indicate that it is probably not possible to predict ionic calcium with assurance and that direct measurement may be necessary for optimal therapy.

Buffers↗
PubMed1975

Blood substitutes.

Substitutes for whole blood include blood fractions such as plasma, serum albumin and other fluids of various kinds which are not derived from blood but are used as plasma volume expanders; these, include the usual crystaloid intravenous solutions. Since in comparison to blood far more of these later solutions are given intravenously, a thorough knowledge of plasma volume expanders is essential. The first use of such expanders in human patients was by Hogan in 1915. He used colloidal gelatin and noted an improvement in blood pressure in shock. In 1945, Gronwall and Ingelman advocated the use of dextran in shock. The reguirements for an acceptable plasma substitute are: a satisfactory colloidal osmotic pressure, constand composition at reasonable cost, a viscosity suitable for intravenous administration, stability in prolonged storage at variable temperatures, and sterilization by autoclaving. Such substances must be either fully excreted or metabolized, and must cause no early or late tissue damage. They must be non-antigenic and pyrogen free. They must cause no change in the blood such as haemolysis, R.B.C. agglutination, increased sedimentation rate and no impairment of haemostasis. The presently available plasma expanders include blood derivatives (plasma, albumin), modified protein (gelatin, oxypolygelatin), polymerized carbohydrates (dextran) and plastics (polyvinyl pyrrolidone-PVP). All these substances expand plasma volume, decrease haematocrit and plasma proteins, increase sedimentation rate and blood pressure. Dextran, PVP and geletin do not alter hepatic function. Dextran and gelatin have no deleterious effects on renal function. Features of the clinically used plasma expanders are: 1. Fresh Frozen Plasma Fresh frozen plasma contains all clotting factors except platelets. The risk of the transmission of hepatitis is present as it is with whole blood. 2. Plasma Protein Fractions Plasma protein fractions are free of hepatitis virus, but may cause arteriolar dilatation and hypotension. 3. Serum Albumin Serum albumin is a concentrated blood protein fraction. It is salt poor, stable and does not transmit the virus of hepatitis. Since it has a high oncotic pressure it is necessary to give significant quantities of clear fluids with it. It is expensive, scarce, and dilutes the clotting factors. It is, however, a first choice for emergency treatment of shock; 4. Dextran The dextrans may be of medium or low molecular weight. They are inexpensive and readily available, and do not transmit the virus of hepatitis. In large amounts they cause a coagulation defect and may be antigenic. Continued.

Blood Proteins↗