Biomedical subjects

R P Sterling

Publications and source records attributed to R P Sterling.

13 recordsLinked to original sources

PubMed1986

Noninvasive conjunctival oxygen monitoring during carotid endarterectomy.

Conjunctival oxygen tension (PcjO2) was measured continuously during carotid endarterectomy in 15 patients to evaluate its sensitivity in patients receiving shunts. These studies suggest that PcjO2 tracks brain perfusion during periods of carotid artery occlusion. Reduced PcjO2 was clearly demonstrated with systemic hypotension, carotid artery clamping, and carotid shunt obstruction and clamping. Monitoring of PcjO2 is noninvasive, easy to perform, offers no danger to the patient, and allows real-time assessment of the local tissue perfusion. It provides valuable information on the effectiveness of carotid oxygen transport and, in conjunction with arterial blood gas values, expresses carotid artery perfusion relative to systemic oxygen transport. Further investigations using the PcjO2 sensor may define criteria for intraoperative carotid arterial shunting in patients with tenuous cerebral perfusion, and for prompt intervention in patients with deteriorating perfusion prior to the onset of life-threatening cerebral ischemia.

Aged↗

PubMed1986

Left coronary artery spasm causing severe left ventricular dysfunction without myocardial infarction.

This report describes a patient with persistent, recurrent left anterior descending coronary artery spasm, which causes marked left ventricular dysfunction in a clinical course that is typical of acute myocardial infarction with hyperacute electrocardiographic changes. However, after emergency coronary artery bypass surgery, the patient had complete reversal of left ventricular dysfunction, with no residual evidence of acute myocardial infarction by electrocardiograph or gated blood pool imaging and no CPK enzyme rise. The patient therefore demonstrates that coronary spasm in some instances clearly precedes the sequence of pathophysiologic events leading to acute myocardial infarction. Our report also demonstrates for the first time in man that massive left ventricular dysfunction may occur in this intermediate coronary syndrome, presenting clinically as impending myocardial infarction. With aggressive surgical intervention and emergency bypass surgery, left ventricular function was restored to normal. Despite the semantic problems of categorizing such patients as having impending myocardial infarction, the severe left ventricular dysfunction and alarming course of this patient's illness was resolved by emergency surgery, suggesting that, in some instances, aggressive therapy is warranted.

Journal Article↗

PubMed1984

Role of coronary artery bypass surgery after intracoronary streptokinase infusion for myocardial infarction.

Intracoronary streptokinase infusion has been shown to improve left ventricular function and reduce hospital mortality in patients with acute myocardial infarction. Adjuvant coronary artery bypass surgery is of value in many of these patients who have recurrent angina, circulatory instability, severe coronary artery occlusive disease, or a high risk of reinfarction. There is little, if any, evidence that immediate coronary artery bypass surgery affects the results adversely--either because of recent myocardial infarction or recent streptokinase infusion, and early operation appears to be a safe and worthwhile modality of treatment in this group of patients with myocardial infarction.

Coronary Artery Bypass↗

PubMed1984

Results of myocardial revascularization in black males.

The impact of black-white differences in the prevalence of risk factors for coronary heart disease on the outcome of coronary bypass surgery has not been well defined. Preoperative status, coronary anatomy, and surgical results were reviewed in 54 black males operated on between December 1970 and August 1983. With the use of criteria established by the New York Heart Association, five patients were classified in class II, 34 were in class III, and 15 were in class IV. Five patients had unstable angina. The most common risk factor, cigarette smoking, occurred in 43 patients (80%). Thirty patients (56%) had hypertension, 10 (19%) were diabetic, 14 (26%) were obese, and 23 (43%) had a family history of coronary disease. Elevated cholesterol and triglyceride levels were present in 8 and 12 patients, respectively. An average of 2.9 grafts per patient was placed. Overall operative mortality was 5.6%. Prior to the use of cardioplegia in 1978, there were two deaths among 14 patients (mortality, 14%). Since 1978 there has been one death among 40 patients (mortality, 2.5%). Although immediate operative mortality appears not to be affected by black-white status, long-term prognosis may be influenced significantly by the high prevalence of hypertension and diabetes and the lower prevalence of hyperlipidemia among black patients.

Adult↗

PubMed1984

Comparison of dopamine and dobutamine therapy during intraaortic balloon pumping for the treatment of postcardiotomy low-output syndrome.

Treatment of postcardiotomy low-output syndrome includes intraaortic balloon pumping (IABP), volume loading, pharmacological afterload reduction, and stimulation with an inotropic agent. This study compares the effectiveness of combined nitroprusside and dopamine therapy and nitroprusside and dobutamine therapy in 12 patients requiring IABP postoperatively. Serial hemodynamic measurements were made before and during infusion of nitroprusside and after administration of the combined therapy (N = 6 in each group). Prior to pharmacological therapy, cardiac index was 1.47 +/- 0.31 L/min/m2 and systemic vascular resistance (SVR) was 3,114 +/- 1,350 dynes sec cm-5 in patients subsequently given dopamine, and 1.59 +/- 0.38 L/min/m2 and 2,661 +/- 405 dynes sec cm-5, respectively, in those given dobutamine. With infusion of nitroprusside, both groups showed significant reduction in SVR. Nitroprusside plus either inotropic agent resulted in augmentation of cardiac index and an additional reduction in SVR, both changes being greater in the group given dopamine. Larger doses of dobutamine than dopamine were needed to achieve similar hemodynamic improvement. We conclude that the addition of an inotropic agent to vasodilator therapy during IABP results in a greater increase in cardiac index and a greater decrease in afterload than a vasodilator alone. In addition to its beneficial effect on renal perfusion at the dose required to effect these improvements, dopamine appears a better inotropic agent than dobutamine for postcardiotomy low-output syndrome.

Aortic Valve↗

PubMed1984

Unusual sequelae of colon interposition for esophageal reconstruction: late obstruction requiring reoperation.

Colon interposition has become a favored technique for esophageal reconstruction. Late morbidity is generally related either to technical problems associated with the procedure or to the development of new disorders in the transposed segment. Two patients are discussed who were seen with obstruction of colon interposition grafts ten and five years after esophageal reconstruction. In the first patient, a volvulus of the interposed colon associated with a chronically narrowed area distal to the looped segment resulted in obstruction. In the second patient, the redundant intrathoracic segment of the colon interposition became kinked at the diaphragmatic hiatus leading to dilatation and incomplete emptying. Both patients underwent successful reoperations and are doing well 10 and 12 months later. The causes and possible prevention of these and other late complications of colon interposition are discussed.

Adult↗

PubMed1984

Comparison of biopsy-proven Pneumocystis carinii pneumonia in acquired immune deficiency syndrome patients and renal allograft recipients.

Pneumonia unresponsive to antibacterial agents in patients with acquired immune deficiency syndrome (AIDS) has become a new indication for lung biopsy. In 14 patients, transbronchial or open-lung biopsy demonstrated Pneumocystis carinii. An additional 12 patients, who were immunosuppressed after renal transplantation, were seen with P. carinii pneumonia. The diagnosis was established by transbronchial biopsy in the majority of patients. All patients were treated initially with trimethoprim plus sulfamethoxazole. Pentamidine was added after diagnosis if improvement did not occur. Both groups demonstrated reversal in the T cell helper: suppressor ratio. We compared these two groups of immunocompromised patients with respect to clinical presentation, lung pathology, response to therapy, and survival. Patients with AIDS were seen with a two- to three-week prodrome of fever, lymphadenopathy, weight loss, and malaise followed by hypoxia and leukopenia within 12 hours. Transplant patients became acutely ill with fever and hypoxia within 24 to 36 hours. In both groups, chest roentgenogram showed bilateral diffuse infiltrates; sputum cultures were generally negative; and lung biopsy demonstrated Gomori-Jones periodic acid-methenamine-silver-positive P. carinii. Mortality was substantially higher in patients with AIDS (50% versus 8%). This difference may be explained by the fact that the T cell defect in AIDS has an infectious cause, while the defect in the renal allograft recipient is pharmacologically mediated.

Acquired Immunodeficiency Syndrome↗

PubMed1984

Early bypass grafting following intracoronary thrombolysis with streptokinase.

Early bypass grafting following intracoronary thrombolysis with streptokinase may be indicated in patients with acute coronary artery thrombosis and severe coronary disease. To evaluate this approach, we prospectively studied 41 patients (32 men and nine women, mean age 53 years) with acute infarction. Emergency cardiac catheterization was performed within 18 hours after onset of chest pain and intracoronary streptokinase was given. All patients underwent bypass 3 to 10 days later (mean 7 days). Serial gated radionuclide left ventricular angiograms to determine ejection fraction were obtained on hospital admission, preoperatively, and 3 to 6 months later. Thirty-four patients had complete occlusion of the artery supplying the infarcted segment. In 30 patients (88%) reperfusion was not successful. In seven patients the artery was not totally thrombosed. Thirty-two patients (78%) had multivessel disease. An average of 2.8 grafts per patient were placed with an operative mortality of 2% (one patient). Serial measurements of ejection fraction were obtained in 23 patients in whom the admission ejection fraction was less than 50%. There was a significant increase in ejection fraction from admission (33% +/- 11%) to the preoperative measurement (41% +/- 9%, p less than 0.001), and this improvement persisted at follow-up (40% +/- 14%). Intracoronary streptokinase has been shown to restore blood flow to infarcting myocardium and to improve left ventricular performance. In patients with significant organic stenosis, the risk of bypass grafting 3 to 10 days after intracoronary streptokinase infusion appears to be no different from the risk of elective operation performed at a time remote from an acute infarction.

Adult↗

PubMed1983

Cefonicid concentrations in serum and atrial tissue during open-heart surgery.

Cefonicid was administered intramuscularly 1 h before open-heart surgery to seven patients in doses of 1 g each and to six patients in doses of 2 g each. Cefonicid concentrations were measured in the right atrial biopsy and in serum at onset of surgery, at time of atrial biopsy, 15 min after starting cardiopulmonary bypass, and at completion of cardiopulmonary bypass. Concentrations in the atrial biopsy and in serum at all periods exceeded the minimal inhibitory concentrations for organisms most frequently responsible for postoperative infections.

Aged↗

PubMed1983

Sustained improvement in left ventricular function and mortality by intracoronary streptokinase administration during evolving myocardial infarction.

One hundred eighty-eight patients with acute myocardial infarction were studied prospectively from August 1980 to September 1982. One hundred thirty-six of these patients were entered into a intracoronary streptokinase study after informed consent was obtained. The remaining 52 patients, who either met exclusion criteria for the study or refused to participate, served as a control group and were treated as those in the study group except that they did not undergo emergency cardiac catheterization. Left ventricular function was determined in both groups by gated radionuclide ejection fraction (EF) on admission to the hospital, at discharge, and 6 months after discharge. With successful reperfusion up to 18 hr after onset of chest pain, mean left ventricular function in the study group improved (EF 39 +/- 13% on admission and 46 +/- 12% at discharge; p less than .001). Mean EF in control patients and those not achieving reperfusion did not change from admission to discharge. Mean EF at 6 month follow-up was not significantly different than at discharge in the study group or the control group. Total cardiac mortality in the control group was 19% compared with 10% in the study group (p = .06, NS). When patients admitted in pulmonary edema or shock (Killip class III or IV) were excluded from both groups, total cardiac mortality in the study group was significantly lower (4%) compared with in the control group (12.5%, p less than .05. The administration of intracoronary streptokinase during evolving myocardial infarction up to 18 hr after onset of chest pain may result in decreased mortality and sustained improvement in left ventricular function.

Aged↗

PubMed1983

Plasma and myocardial levels of cefonicid during open-heart surgery.

To minimize the incidence of postoperative infections in patients undergoing open-heart surgery, antibiotics should maintain tissue concentrations greater than the minimal inhibitory concentration (MIC) for potential pathogens (eg, Staphylococcus) for the duration of the operation. The ability of cefonicid, a new β-lactamase-resistant parenteral cephalosporin, to attain plasma and myocardial levels greater than the MIC (4.8 to 5.0 μg/mL) for penicillin-resistant Staphylococci was assessed in 13 patients. Six patients were administered 1 g and seven patients were administered 2 g of cefonicid IM one hour prior to surgery. In all patients the plasma concentrations of the drug were determined at the start of surgery, 15 minutes after the patient was placed on cardiopulmonary bypass (CPB), and at the completion of CPB. In addition, the concentration of cefonicid was determined in a right atrial biopsy. It was found that both 1 g and 2 g of cefonicid administered one hour prior to surgery resulted in plasma and myocardial levels greater than the MIC for the organisms most frequently implicated in postoperative infections.

Aged↗

PubMed1982

Streptokinase reperfusion and early surgical revascularization in patients with acute myocardial infarction.

During a 21-month period, 150 patients with acute myocardial infarction were offered entry into a study comprising emergency cardiac catheterization, streptokinase infusion for thrombus if present, and coronary artery bypass surgery where appropriate. Forty refused or were excluded, and served as a control group. Approximately 80% of the remainder had coronary thrombosis and obtained benefit as a group from streptokinase reperfusion. Among the 44 who had coronary artery bypass mortality was low except in those having cardiogenic shock at the time of operation. Those without coronary thrombosis appeared to have a better result from early than from delayed operative revascularization. It appears that both streptokinase reperfusion and early coronary artery bypass have a beneficial role in the management of patients with acute myocardial infarction.

Cardiac Catheterization↗

PubMed1982

Late failure of prosthetic heart value.

A 20-year-old woman developed late thrombosis of a 22 mm Lillehei-Kaster mitral valve prosthesis. Despite adequate anticoagulation measures, clinical detection of significant dysfunction of this particular prosthesis is difficult because of the absence of distinctive opening and closing sounds and the radiolucent character of the disc. Early diagnostic catheterization may be warranted.

Adult↗