Biomedical subjects

A R Kerr

Publications and source records attributed to A R Kerr.

At least 37 records · Page 2Linked to original sources

PubMed1983

Serum myoglobin concentration as an index of myocardial damage after cardiac surgery.

We assessed serum myoglobin concentration as an index of myocardial damage after cardiothoracic surgery in a dog model and man. Experimentally, we compared 12 dogs subject to left thoracotomy either with or without coronary artery ligation to cause an infarct. Serial blood sampling for 24 hours after surgery showed that the times taken for the myoglobin peak concentrations to appear distinguished the two groups without overlap. These times were 2.4 +/- 0.4 hours after surgery without ligation compared with 9.8 +/- 0.8 hours in the ligated group (P less than 0.001). Clinically, serial sampling was performed over 48 hours in 20 patients having undergone cardiac surgery involving cardiopulmonary bypass. A further 80 patients were investigated for 12 hours. Myoglobin was compared with the activities of creatine kinase, 2-hydroxybutyrate dehydrogenase and glutamate-oxaloacetate transaminase in relation to electrocardiographic criteria of myocardial damage. A myoglobin peak greater than 800 micrograms/1 appearing later than 6 hours after starting bypass was found in those patients suffering myocardial damage. The appearance times and activities of the enzymes tested were widely scattered and difficult to interpret. We conclude that blood samples taken at approximately 3 and 6 hours after starting bypass should suffice to characterise both peak myoglobin and its time of appearance which together form a sensitive index of myocardial damage. However, this conclusion is limited by the low incidence of myocardial damage (3%) in this group of patients.

Animals↗

PubMed1982

Late follow-up of the Braunwald-Cutter valve.

A retrospective review has been made of 234 patients who received 239 Braunwald-Cutter valves (109 aortic, 130 mitral). For the aortic valve, the thromboembolic rate was very high (10.3 per 100 patient-years). This was associated with severe strut cloth wear in 94.5% of valves and with long strands of fibrin attached to the worn cloth in 58% of valves studied at reoperation or postmortem examination. The aortic poppet showed a mean decrease in volume of 4%, and poppet escape was recognized in 4 patients. The actuarial incidence of poppet escape was less than that predicted in earlier reports. There was a 4% incidence of stenosis of the valve. The hospital mortality associated with removal of the aortic Braunwald-Cutter valve and replacement with another device was 4%. Performance of the mitral Braunwald-Cutter valve appears satisfactory to date (mean follow-up, 42 months). Its electric removal is not recommended.

Actuarial Analysis↗

PubMed1981

Infective endocarditis: a lethal disease.

One-hundred-and-eighty-nine episodes of infective Endocarditis were seen in 177 patients in the Green Lane Cardiology Unit over a 18-year period. Hospital survival was 79% and 13-year actuarial survival was 47%. A number of factors including the underlying cardiac lesion, infecting organism, clinical features and surgical intervention were related to outcome. No patient with extreme heart failure survived without operation. Hospital survival in patients with severe heart failure was 69% (9/13 patients) where surgery was carried out before completion of antibiotic treatment, and 40% (6/15 patients) where the antibiotic course was completed. Survival was 53% in patients who still had a fever after one week of antibiotic treatment and 96% if the temperature was normal. In 61% of patients with a fever at one week, extended infected pannus was present compared with 6--10% where the temperature was normal. In patients undergoing operation before completion of antibiotics, the surgical mortality was higher but neither the incidence of recurrence of endocarditis nor the need for re-operation was increased. We believe that better results will be achieved with a policy of surgical intervention when signs of infection and heart failure have not settled within one week of treatment.

Actuarial Analysis↗

PubMed1981

Coronary surgery after recurrent myocardial infarction: progress of a trial comparing surgical with nonsurgical management for asymptomatic patients with advanced coronary disease.

A randomized trial of surgical vs nonsurgical management was carried out in men 60 years of age or younger who had recovered from a recurrent myocardial infarction. Of 205 patients considered, 100 had few or no symptoms and had coronary vessels favorable for bypass grafting; these patients fulfilled the trial conditions and were randomized (50 surgical and 50 nonsurgical). In 41 patients (elective nonsurgical group), randomization was not considered justifiable because of relatively unfavorable coronary anatomy or severe left ventricular dysfunction. Nineteen patients had elective surgery because of disabling angina despite full medical treatment or because of significant left main coronary stenosis. In 45 patients, coronary angiography was not undertaken because of medical contraindications or reluctance of the patient to enter the study. Actuarial survival curves (mean follow-up 4.5 years) show an annual mortality rate of 3-4% per year for all investigated patients, and no advantage for the randomized surgical over the randomized nonsurgical group. The results suggest that in the absence of disabling angina or left main coronary artery stenosis, coronary artery surgery need not be advised for survivors of recurrent infarctions who have severe coronary artery disease. Moreover, the prognosis for the group of patients not treated surgically appears to be better than has been previously described.

Adult↗

PubMed1980

Mitral valve vegetations in bacterial endocarditis resembling left atrial myxoma.

A patient with Staphylococcus aureus endocarditis is reported whose echocardiogram closely resembled that found in left atrial myxoma. Because of severe mitral incompetence, the valve was replaced using cardiopulmonary bypass and at operation a large 3 cm friable vegetation was found attached to the posterior leaflet of the mitral valve. Histological examination showed changes typical of bacterial endocarditis with no evidence of myxoma.

Aged↗

PubMed1977

Anaesthesia with profound hypotension for middle ear surgery.

To produce a blood-free field for middle ear surgery performed with the operating microscope, the arterial systolic pressure was reduced to less than 50 mm Hg in 700 patients by means of thiopentone-halothane-nitrous oxide in oxygen anaesthesia together with pentolinium tartrate. In 84% the results were excellent, in 12% moderately good and they were poor in 4%. There were more unsatisfactory results in males (22.8%) than in females (11.4%). In spite of the arterial pressure being reduced to very low values in many instances, there was no mortality or morbidity which could be ascribed to the technique.

Adult↗

PubMed1977

Isolated mitral replacement with stent-mounted antibiotic-treated aortic allograft valves.

The results of valve replacement with a stent-mounted antibiotic-treated aortic allograft valve are reported in 129 patients with isolated mitral valve disease. Of these patients, 70 per cent were in N.Y.H.A. Class IV. The hospital mortality rate was 3.9 percent. The cumulative complication-free rate at 5 years was only 37 percent as 21 percent died late, a further 15 percent were alive following reoperation, 4 percent had an embolic episode, 4 percent were alive with important incompetence, and 20 percent had unimportant incompetence. Proved valve failure was due mainly to detachment of the aortic wall remnant of the valve from the pillar of the rigid metal stent (16 percent incidence at 5 years) and methods for preventing this complication are discussed. Because of these complications the use of this device in the mitral position has been discontinued.

Adolescent↗

PubMed1976