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Biomedical subjects

D A Murphy

Publications and source records attributed to D A Murphy.

At least 145 records · Page 8Linked to original sources
PubMed1980

Hypertension following myocardial revascularization: its prevalence and etiology.

Of 11 patients who underwent elective aortocoronary bypass operation using nonpulsatile flow with moderate hypothermia (28 degrees C), 8 had hypertension defined as blood pressure of 160/100 mm Hg or greater. The plasma renin level was not elevated during bypass by postoperatively in the intensive care unit it became significant (P < 0.05) elevated. An increase in the release of renin was associated with a rise in systemic vascular resistance and coincided with the onset of hypertension. Although the values of plasma catecholamines were elevated during bypass and in the intensive care unit, they did not appear to contribute appreciably to increases in systemic resistance. The authors conclude that an increase in the release of renin is associated with increased vascular resistance and elevated blood pressure following myocardial revascularization.

Adult↗
PubMed1980

Bone scan utilization in the differential diagnosis of exercise-induced lower extremity pain.

In 4 patients with lower extremity pain and either negative or equivocal radiograhic findings, the bone scan was definitely positive for stress fracture in all, accurately localized the lesion, and permitted proper therapy. The condition in all instances proved to be a microfracture at the origin or insertion of a muscle. The pain was always intensified by physical activity.

Adult↗
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

Surgical correction of pulmonary atresia with multiple large systemic-pulmonary collaterals.

A young patient in whom the pulmonary blood flow was supplied completely by five systemic-pulmonary collaterals underwent reconstruction of the pulmonary outflow tract by a new technique. This consisted of the insertion of a valve-bearing conduit between the right ventricle and an isolated segment of the descending aorta, which gave rise to three of the collaterals. Although the patient had a hypoplastic pulmonary artery confluence, other factors mitigated against its use as the sole conduit for right ventricular output.

Aorta, Thoracic↗
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↗
PubMed1979

Effect of cardiopulmonary bypass and hypothermia on pancreatic endocrine function and peripheral utilization of glucose.

Extracorporeal circulation has been reported to produce abnormalities of glucose, metabolism. Pancreatic endocrine function and peripheral glucose utilisation were studied in 11 nondiabetic patients who underwent myocardial revascularization. Nonpulsatile flow with hemodilution and moderate hypothermia to 28 degrees C were used in each case. Following the onset of cardiopulmonary bypass, serum glucose values rose rapidly to a mean of 972 mg/dl (54.0 mmol/l) and were associated with high circulating concentrations of insulin in the range of 216 microU/ml [1549.8 pmol/l]. High circulating concentrations for both insulin and glucose were maintained throughout the bypass period. These returned to normal postoperatively when the patient was in the recovery room. The results of this study indicate that both the pancreatic endocrine response and the peripheral utilization of glucose are impaired during cardiopulmonary bypass with hemodilution and moderate hypothermia to 28 degrees C.

Adult↗
PubMed1979

Hereditary polyposis coli. II. Genetic counseling.

The problems of genetic counseling in hereditary polyposis coli (HPC)(taken as the type of the age-dependent dominant mendelian trait) are discussed in some detail. They are threefold: first to formalize, for purposes of decision, the total penalty (the "fardel") typically imposed by the disorder for each case, and how it may be modified by treatment; second, to determine the logical issues involved in making probability statements in the face of the uniqueness of each case; third, to use to best advantage the information on the pattern of onset to assess the probability that a person, at risk but not so far affected, does in fact harbor the gene. The third problem points up the need for a formal model of the pathogenesis and its implications for the pattern of onset and the sensitivity of the assessment to the assumptions of the model, especially where one has to rely on cross-sectional, as distinct from longitudinal, data.

Colonic Neoplasms↗
PubMed1978

Anomalous origin of left main cononary artery from anterior sinus of Valsalva with myocardial infarction.

The origin of the left main coronary artery, or its branches, from the right or anterior sinus of Valsalva is a recognized congenital anomaly. The origin of the entire left main coronary artery from a separate ostium in the right sinus of Valsalva and its course to the right and behind the ascending aorta, in a living patient without associated congenital heart disease, has not been described. This anomaly was recognized as the cause of an anterior myocardial infarction in a 12-year-old girl, and it is the subject of this case report.

Aorta↗
PubMed1978

Assessment of the isolated right atrium as a pump.

The ability of the hemodynamically isolated dog right atrium to pump against a resistance equivalent to normal pulmonary artery pressure was tested in an in vivo preparation. At a preload of 10 mm. Hg, the right atrium reached a peak systolic pressure of 18.2 mm. Hg (+/- 1.3 S.E.M.) against an afterload of 12 mm. Hg, but it could eject a flow only equivalent to 53 percent (+/-6) of the dog's cardiac output (n = 6). At a preload of 15 mm. Hg, a peak systolic pressure of 21.5 mm. Hg (+/- 0.8) was recorded against an afterload of 17 mm. Hg, but again, only 55 percent +/-5) of the dog's cardiac output was ejected. It appears that the cardiac output from the nonhypertrophied right atrium is limited by the strength of the right atrial contraction and the physiological limits imposed by the venous driving pressure.

Animals↗
PubMed1977

Effect of unilateral pulmonary artery occlusion on the arterial oxygen pressure of children undergoing pulmonary systemic artery shunt procedures.

Of 20 children undergoing thoracotomy who had blood-gas analysis at various intervals during their operative procedure, 18 had congenital heart disease causing cyanosis. The venous admixture was apparent on compressing the lung to expose the mediastinal structures and was diminished upon clamping the pulmonary artery to the exposed lung. This observation may be of clinical value in raising the arterial oxygen pressure when sudden deterioration occurs during performance of a systemic pulmonary shunt in cyanotic children.

Blood Gas Analysis↗
PubMed1976

Use of a membrane oxygenator for open-heart surgery in infants.

Because use of the bubble oxygenator during open-heart surgery is associated with complications such as hemolysis, pulmonary insufficiency and oliguria, a membrane oxygenator was used in conjunction with hypothermia in 37 infants. The main features of the oxygenator are gravitational blood flow, oxygenation into an airless, collapsible blood reservoir, low-flow roller pump flow back to the patient, accurate determination of flows and careful use of a heat exchanger. Gas flow (98% oxygen, 2% carbon dioxide) for the unit of 2 m2 is maintained at 3 to 4 1/min. Specific precautions are taken to ensure absence of bubbles. Three prime solutions are used, the final one having an osmolality of 381 mOsmol and containing 129.9 meq of sodium, 3.8 of potassium and 94.0 of chloride and 2001 mg/dl of glucose. Six patients died, but none of the deaths could be directly related to the use of the oxygenator. Respiratory complications were minimal, as were other complications. The technique is reliable in oxygenating blood in an tracorporeal circulation, but further familiarity with the membrane oxygenator for use in open-heart surgery in infants is desirable before firm conclusions can be drawn as to its value.

Cardiac Surgical Procedures↗
PubMed1976

Fatal cerebral embolus - a complication of left ventricular venting.

A 3-year-old child died following a routine tetralogy of Fallot repair. Death was caused by a cerebral embolus. Injury to the left ventricle during left ventricular venting resulted in an apical myocardial infarct. The embolic source was a mural thrombus covering the area of infarction. A technique is described whereby left ventricular venting can be avoided during open-heart surgery in small patients.

Cardiac Catheterization↗