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Biomedical subjects

F L Grover

Publications and source records attributed to F L Grover.

At least 91 records · Page 5Linked to original sources
PubMed1994

Mechanisms of coronary vasomotor dysfunction in the transplanted heart.

The transplanted heart sustains both cold ischemic and reperfusion injuries. These can produce coronary vascular endothelial or smooth muscle injury or both, which, in turn, can produce coronary vasomotor dysfunction. Using a canine model of autologous heart transplantation, we examined the following coronary vasomotor control mechanisms in isolated coronary artery rings: (1) endothelial-dependent cyclic guanosine monophosphate (cGMP)-mediated vasorelaxation (response to acetylcholine); (2) endothelial-independent cGMP-mediated vasorelaxation (response to sodium nitroprusside); and (3) beta-adrenergic cyclic adenosine monophosphate (cAMP)-mediated vasorelaxation (response to isoproterenol hydrochloride). Further, these mechanisms were related to 3 hours of cold ischemia alone and to 3 hours of cold ischemia plus 1 hour of reperfusion. Autologous heart transplantation was performed in dogs, and isolated distal left anterior descending coronary artery rings were studied in individual organ chambers. Cold ischemia alone produced significant dysfunction of beta-adrenergic cAMP-mediated vasorelaxation, which was exacerbated after reperfusion. Neither endothelial-dependent nor endothelial-independent cGMP-mediated vasorelaxation was dysfunctional after cold ischemia alone, but both were significantly impaired after reperfusion. We conclude that cold ischemia and reperfusion each produce coronary vasomotor dysfunction in the transplanted heart. Cumulatively, such coronary vasomotor dysfunction can acutely impair coronary vasodilatation and potentially jeopardize myocardial blood flow in the transplanted heart.

Acetylcholine↗
PubMed1994

The Veterans Affairs Continuous Improvement in Cardiac Surgery Study.

The Department of Veterans Affairs Cardiac Surgery Consultants Committee is responsible for reviewing the quality of cardiac surgical treatment at the 43 Veterans Affairs cardiac surgical centers where these procedures are performed. It does so by reviewing both the unadjusted and risk-adjusted operative mortality data and the incidence of perioperative complications. These data are reviewed by the committee semiannually, and the overall summary and hospital-specific data are shared with the individual cardiac surgical program directors. Paper audits and site visits are performed when indicated by increased unadjusted and risk-adjusted operative mortality. Constructive criticism is shared with the program director and medical center administration. The relative risk of death for numerous patient risk factors has been estimated, and is now used in prospective clinical decision making. During the 7-year period that risk-adjusted outcomes have been utilized, there has been an overall significant reduction in the observed-to-expected operative mortality ratio. Although many factors could have contributed to this, including continually improving surgical techniques, it is also likely that part of this improvement has occurred because of the continuous feedback of these quality improvement data to our cardiothoracic surgeons and cardiologists.

Cardiac Surgical Procedures↗
PubMed1994

Provider perceptions in using outcomes data to improve clinical practice.

In this article we report on the perceptions of health care providers concerning the use of health care outcomes. These perceptions were identified during two afternoon workshops at the symposium on outcomes data held in Keystone, Colorado, in June 1994. The overall goal of these workshops was to explore the potential use of outcomes data within the clinical practice setting. The attitudes and concerns of several key providers formed the framework for the workshop discussions. The strengths and weaknesses associated with using risk-adjusted outcomes data, both to assess and to improve quality of patient care, were debated within the workshop groups. Overall, conference participants agreed that the risk-adjusted outcomes of cardiac care could be used both to assess and to improve the quality of patient care. The research to date, however, represents only a first step toward this goal. The meeting participants challenged the research community to improve on the measures currently available, with the goal of providing clinicians better information to improve the "art" of medicine.

Attitude of Health Personnel↗
PubMed1994

Continuous assessment and improvement in quality of care. A model from the Department of Veterans Affairs Cardiac Surgery.

OBJECTIVE: The authors organized the Department of Veterans Affairs (VA) Continuous Improvement in Cardiac Surgery Study (CICSS) to provide risk-adjusted outcome data for the continuous assessment and improvement of quality of care for all patients undergoing cardiac surgery in the VA. BACKGROUND: The use of risk-adjusted outcomes to monitor quality of health care has the potential advantage over consensus-derived standards of being free of preconceived biases about how health care should be provided. Monitoring outcomes of all health care episodes, as opposed to review of selected cases (e.g., adverse outcomes), has the advantages of greater statistical power, the opportunity to compare processes of care between good and bad outcomes, and the positive psychology of treating all providers equally. These two concepts, together with a pre-existing peer committee (the VA Cardiac Surgery Consultants Committee) to review, interpret, and act on the risk-adjusted outcome data, form the primary design considerations for CICSS. METHODS: Patient-level risk and outcome (operative mortality and morbidity) data are collected prospectively on each of the approximately 7000 patients undergoing cardiac surgery in the VA each year. These outcomes, adjusted for patient risk using logistic regression, are provided every 6 months to each cardiac surgery program and to a national peer review committee for internal and external quality assessment and improvement. RESULTS: For the most recent 12-month period with complete data collection, observed-to-expected (O/E) ratios ranged from 0.2 to 2.2, with eight centers falling outside of the 90% confidence limits for an O/E ratio equaling 1.0. The O/E ratio for all centers has fallen by 14% over the 4.5-year period of this program (p = 0.06). CONCLUSIONS: A large-scale, low-cost program of continuous quality improvement using risk-adjusted outcome is feasible. This program has been associated with a decrease in risk-adjusted operative mortality.

Cardiac Surgical Procedures↗
PubMed1994

Transesophageal echocardiography in the evaluation of a transmediastinal gunshot wound: case report.

Transesophageal echocardiography is a safe, minimally invasive imaging modality that may be useful in the evaluation of transmediastinal gunshot wounds. In this report, we describe a hemodynamically stable patient who sustained a gunshot wound to the ascending aorta. Routine diagnostic evaluation, including aortography, failed to confirm the suspected diagnosis. Transesophageal echocardiography definitively detailed the injury to the aorta enabling definitive surgical repair.

Adult↗
PubMed1994

The role of CT and MRI in staging of the mediastinum.

Lung Cancer Study Group (LCSG) Protocol 883, the comparative study of the results of magnetic resonance imaging (MRI) and computerized tomography (CT) for staging of tumor, nodal, and selected metastatic sights in patients with surgically staged lung cancer was activated in August 1988 but was not completed because of termination of LCSG funding. A literature review was therefore undertaken to determine the results of other studies that were performed to evaluate the relative efficacy of MRI and CT in the staging of patients with lung cancer. These studies determined that CT and MRI are approximately equal in the staging of N2 disease with a sensitivity of 70 to 90%, a specificity of 60 to 90%, and an accuracy of 66 to 90% depending on the criteria used for determining positive nodes and the compulsiveness of surgical staging. Magnetic resonance imaging is probably better in the assessment of superior sulcus tumors, tumors involving the aorta-pulmonary window, hilar nodes, in assessing chest wall or diaphragmatic invasion, and in evaluating patients whose CT findings are equivocal. Computed tomography and MRI reveal adrenal abnormalities in 10 to 20% of patients but only one third of these have metastases. Mediastinoscopy has a sensitivity of 85 to 90%, a specificity of 100%, and an accuracy of about 95% and is therefore the gold standard for N2 staging. If the CT examination reveals no N2 disease, one can proceed directly to thoracotomy with approximately a 15% chance of finding N2 disease. It was concluded that because CT is much cheaper, it should therefore be used for the noninvasive staging of patients with lung cancer unless the above-noted special circumstances are present that have been shown to favor MRI. Because of the limited accuracy of CT and MRI, however, positive findings must be confirmed by biopsy specimens and pathologic study.

Carcinoma, Non-Small-Cell Lung↗
PubMed1994

Use of cytomegalovirus (CMV) hyperimmune globulin for prevention of CMV disease in CMV-seropositive lung transplant recipients.

Our data suggest that CMVIG in combination with ganciclovir effectively reduces the incidence, and delays the onset of CMV infections in seropositive lung transplant recipients. In addition, its use may be associated with less severe CMV infection and a lower incidence of bacterial or fungal opportunistic infection. Although the number of patients in the study is small, high-titer CMVIG may be more effective than standard titer immunoglobulin in the prevention of CMV disease in lung transplant recipients. Several questions remain in addition to these: What is the optimal dosage and duration of treatment with CMVIG for prophylaxis of CMV infection and disease in lung transplant recipients; Is this strategy cost-effective; Will it reduce the incidence of obliterative bronchiolitis following lung transplantation and enhance allograft survival? A prospective, random-assignment trial is warranted to answer these questions.

Acyclovir↗
PubMed1994

Determinants of the occurrence of and survival from prosthetic valve endocarditis. Experience of the Veterans Affairs Cooperative Study on Valvular Heart Disease.

For the determination of the risk factors associated with the development of and death caused by prosthetic valve endocarditis, data were reviewed from 66 patients who were prospectively entered into the Veterans Affairs Cooperative Study on Valvular Heart Disease and in whom prosthetic valve endocarditis subsequently developed. Data were recorded at 13 medical centers between October 1977 and September 1982 in patients randomized to receive a mechanical valve (Bjork-Shiley spherical disc, n = 510 patients) or a bioprosthetic valve (Hancock porcine heterograft, n = 522 patients). The average rate of prosthetic valve endocarditis development was 0.8% per year over an average follow-up period of 7.7 years. Of the 66 patients in whom prosthetic valve endocarditis developed (5.8%), 15 cases occurred within 2 months of operation (early) and 51 occurred after operation (late). The most significant preoperative predictor of prosthetic valve endocarditis was active endocarditis at the time of operation (7.4% versus 0.9%) (p = 0.001). Early prosthetic valve endocarditis occurred more frequently in patients who underwent operation for multivalvular disease (p = 0.023). Significantly related perioperative variables were coma, prolonged mechanical ventilation, deep postoperative wound infection, postoperative jaundice, ventricular tachycardia, ventricular fibrillation, and replacement of more than one valve (p < 0.05). Multivariate predictors were hypoxia (p = 0.001), preoperative endocarditis (p = 0.003), preoperative valve lesion (p = 0.020), and resident surgeon (p = 0.05). Significant preoperative variables predictive of late prosthetic valve endocarditis were mitral stenosis and mixed mitral stenosis-regurgitation. The only multivariate predictor of late prosthetic valve endocarditis was superficial wound infection (p = 0.004). Of deaths attributable to prosthetic valve endocarditis, 41% occurred in patients treated with antibiotics alone, 48% occurred in patients treated with surgical intervention and antibiotics, and death resulted in both patients who received no treatment. No difference was found in the risk of early or late postoperative prosthetic valve endocarditis developing in patients receiving the mechanical valve versus those receiving the bioprosthetic valve.

Actuarial Analysis↗
PubMed1994

Comparison of the causes of late death following aortic and mitral valve replacement. VA Co-operative Study on Valvular Heart Disease.

This report examines and compares the causes of late non-surgical death in 146 of 690 (21%) patients undergoing isolated aortic valve replacement (AVR) and in 79 of 273 (29%) patients undergoing mitral valve replacement (MVR) over a five year follow up period. The distribution of valve related, cardiac but not valve-related and non-cardiac deaths was 43%, 23% and 34% respectively for AVR and 65%, 29% and 6% respectively for MVR; the difference between these distributions was statistically significant. The specific causes of valve related deaths included bleeding (11% vs. 5% for MVR vs. AVR), systemic embolization (6% vs. 4% for MVR vs. AVR), endocarditis (14% vs. 8% for MVR vs. AVR), valve regurgitation (8% vs. 5% for MVR vs. AVR) and valve obstruction (3% vs. 5% for MVR vs. AVR). Sudden death (less than one hour from the onset of acute symptoms) accounted for 23% of deaths for MVR and 16% for AVR. The deaths due to congestive heart failure with normal prosthetic valve function were 13% and 8% for MVR and AVR respectively. Non-cardiac causes accounted for only 6% of MVR deaths but 34% of AVR deaths (p < 0.001). There was no significant difference in the late mortality between mechanical and bioprosthetic valves in the aortic position (24% vs. 22%), but the cumulative rate of late deaths was higher in patients with the Björk-Shiley than with the Hancock valve in the mitral position (41% vs. 25%, p < 0.02). In conclusion, about one quarter of patients surviving either aortic or mitral valve replacement died within five years.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Hemodynamic advantage of left atrial epinephrine administration after cardiac operations.

Cardiac surgical patients frequently require catecholamines, typically administered via the central venous circulation. Potential disadvantages of this route of administration include catecholamine metabolism by the pulmonary vascular bed before gaining access to the heart and pulmonary vasoconstriction producing increased pulmonary vascular resistance. We therefore prospectively compared administration of epinephrine via the left atrium versus central venous administration of epinephrine with particular interest in cardiac output, mean pulmonary artery pressure, and pulmonary vascular resistance. Fifteen consecutive aortocoronary bypass patients were studied after cardiopulmonary bypass. Epinephrine (mean dose, 0.07 +/- 0.02 micrograms.kg-1.min-1) was administered via the central venous route, then via the left atrium, then via the central venous route again. Hemodynamic data were collected 10 minutes after changing the route of administration. Left atrial administration of epinephrine produced a 35% greater cardiac output, 25% lower pulmonary artery pressure, and 32% lower pulmonary vascular resistance when compared with central venous administration (all significant; p < 0.05). Left atrial epinephrine administration may offer hemodynamic advantage in cardiac surgical patients in whom central venous administration does not produce an adequate cardiac output or in patients with pulmonary hypertension to avoid any further increase in pulmonary vascular resistance.

Aged↗
PubMed1993

Factors predictive of operative mortality among coronary artery bypass subsets.

As risk-adjusted outcome is increasingly being used to make clinical decisions and to assess and improve quality of care, it is important to develop simple, stable models for predicting outcome. Here we address the hypothesis that a risk factor for increased operative mortality at coronary artery bypass grafting may have differential effects in subgroups of patients defined by the presence or absence of other risk variables. We used a series of univariate and multivariate analyses to identify a group of ten patient-related preoperative characteristics independently predictive of operative death in the total population of 12,712 patients undergoing coronary artery bypass grafting at 43 Department of Veterans Affairs medical centers participating in the Department of Veterans Affairs Continuous Improvement in Cardiac Surgery Study. Separate logistic regression models were then developed for each of 14 clinically important subgroups defined by the presence or absence of seven risk variables. Odds ratios for operative death and estimated operative mortality were calculated from these subgroup regression models. Of 65 comparisons of pairs odds ratios of preoperative risk variables between the subgroups with and without a second risk variable, only five were found to be significant (p < 0.05 without adjustment for multiple comparisons); this is only slightly more than would be expected by chance alone. Risk factors for increased operative death appear to have similar odds ratios for subgroups of patients defined by a second risk variable. This finding greatly simplifies the use of predicted operative mortality in clinical decision making and quality assessment and improvement in coronary artery bypass grafting.

Aged↗
PubMed1993

Primary left atrial myxosarcoma.

A patient in whom rapidly progressive congestive heart failure developed due to the presence of a left atrial myxosarcoma is described. The histologic picture is consistent with the hypothesis that cardiac myxoid tumors are neoplasms derived from undifferentiated cells found in the endocardium. Unfortunately, most cardiac malignancies are detected too late for curative resection, and palliation remains the mainstay of therapy.

Adult↗
PubMed1993

Cold ischemia and reperfusion each produce pulmonary vasomotor dysfunction in the transplanted lung.

Pulmonary vascular resistance is significantly increased in the transplanted lung. We hypothesized that the ischemic or reperfusion injuries incurred by the transplanted lung may produce pulmonary vasomotor dysfunction, which in turn may produce increased pulmonary vascular resistance. In a dog model of autologous lung transplantation, the purpose of this study was to examine the following mechanisms of pulmonary vasomotor control and to relate each of them to cold ischemia and to reperfusion: (1) endothelium-dependent cyclic guanosine monophosphate-mediated vasorelaxation (response to acetylcholine 10(-6) mol/L), (2) endothelium-independent cyclic guanosine monophosphate-mediated vasorelaxation (response to sodium nitroprusside 10(-6) mol/L), and beta-adrenergic cyclic adenosine monophosphate-mediated vasorelaxation (response to isoproterenol 10(-6) mol/L). Autologous right lung transplantation was performed in five dogs. At each of three times, two third-order pulmonary arteries were dissected from each transplanted lung and studied: control (immediately after harvest), cold ischemia (3 hours in 4 degrees C saline solution), and cold ischemia plus reperfusion (1 hour after lung reimplantation). The vasorelaxing effects of acetylcholine, sodium nitroprusside, and isoproterenol were studied in isolated pulmonary arterial rings, suspended on fine wire tensiometers in individual organ chambers. Statistical analysis was by analysis of variance. Results demonstrated significant dysfunction of beta-adrenergic cyclic adenosine monophosphate-mediated relaxation after cold ischemia alone, and this dysfunction was exacerbated by reperfusion. Endothelium-dependent cyclic guanosine monophosphate-mediated relaxation was not impaired by cold ischemia alone but was significantly impaired by reperfusion. Endothelium-independent cyclic guanosine monophosphate-mediated relaxation was not impaired by cold ischemia or reperfusion. We conclude that cold ischemia and reperfusion each produce different patterns of pulmonary vasomotor dysfunction. Cumulatively, such dysfunction may contribute to increased pulmonary vascular resistance in the transplanted lung.

Animals↗
PubMed1992

Salvage angioplasty: an alternative to high risk surgery for unstable angina?

This prospective, Human Subjects Committee and Ethics Committee approved investigation was performed to determine if coronary angioplasty (PTCA) might be a reasonable alternative revascularization method for unstable angina patients thought to be at high risk for operative (CABG) mortality. Between March 1990 and October 1991, thirty-four consecutive patients with medically refractory rest angina were deamed to have high risk of surgical mortality and underwent PTCA without surgical backup. Predicted operative mortality was calculated for each patient based upon the VA Surgical Risk Assessment model. Angioplasty of 52 vessels was attempted. Reduction in lumenal narrowing to < 50% and improved angiographic flow was obtained in 47 vessels. There were four complicating infarctions. One death occurred in the lab, and three patients with unsuccessful angioplasty died within 30 days of pump failure. Relief of angina occurred in 30/34. Thirty patients were discharged home. In follow-up from 1 to 12 months, there have been 2 late sudden deaths at 4 months and 9 months, 1 death from lung cancer; 4 patients have stable exertional angina; 2 are awaiting heart transplant but are pain free, and one patient who had PTCA during cardiogenic shock from acute myocardial infarction had elective coronary artery bypass surgery. There have been no late myocardial infarctions. The observed angioplasty 30-day mortality of 11.8% (95% confidence limit 1% to 22.6%) compares favorably with the predicted operative mortality of 23.8% for this group. This prospective but non-randomized series supports the concept that balloon angioplasty may be a reasonable alternative to surgical intervention in some patients with unstable angina and high risk for surgery. A prospective randomized trial is warranted.

Adult↗
PubMed1992

Risk of major elective operation after myocardial revascularization.

Although an increased surgical risk of ischemic myocardial disease is widely accepted, amelioration of this risk after coronary artery bypass is poorly defined. We compared the outcomes of major elective general and peripheral vascular operations in 181 patients with prior coronary artery bypass grafting (CABG) with outcomes in an age-, gender-, and procedure-matched group without prior CABG (NOCABG). Despite the perception of a greater operative risk in the CABG patients (more CABG patients in American Society of Anesthesiologists [ASA] class III and fewer in ASA class I, p < 0.001), mortality (1.1% CABG versus 2.8% NOCABG) and morbidity (18.8% CABG versus 18.5% NOCABG) rates in the two groups were not significantly different. For patients who have undergone successful CABG, it appears that: (1) the risk of subsequent elective major general and vascular surgical operations is similar to that of an age-, gender-, and procedure-matched cohort, and (2) the mortality rate after elective operations is low.

Age Factors↗
PubMed1992

Single lung transplantation. Factors in postoperative cytomegalovirus infection.

Thirty-one single lung transplantations were performed between March 17, 1988, and November 1, 1990. Postoperative infection, especially with cytomegalovirus, has been the major cause of morbidity and mortality. Eighteen of the 31 patients were receiving prednisone before transplantation. Every patient was prepared preoperatively with oral cyclosporine 5 mg/kg and azathioprine (Imuran) 2 mg/kg. Every patient received methylprednisolone for 3 days postoperatively, followed by prednisone 1.0 mg/kg/day, oral cyclosporine, and azathioprine. Ten patients additionally had cytolytic therapy with OKT3 and 12 with antilymphocyte globulin. Nine patients had no cytolytic therapy. Cytolytic therapy was chronologic, not randomized. Postoperative infection occurred in 20 patients, 13 of whom had cytomegalovirus infection. Preoperative use of prednisone did not correlate with postoperative infection, cytomegalovirus, or death. Postoperative infection occurred in 17 of 22 patients with cytolytic therapy compared with three of nine without cytolytic therapy (p = 0.035). Cytomegalovirus infection occurred in 13 of 22 with cytolytic therapy and in none of the nine without cytolytic agents (p = 0.003). Therefore preoperative prednisone does not appear to be a contraindication to single lung transplantation. Cytolytic therapy with either OKT3 or antilymphocyte globulin increases the prevalence of postoperative infection with cytomegalovirus and should not be used in patients undergoing lung transplantation.

Contraindications↗
PubMed1992

Chest trauma. Approach and management.

A synopsis of both blunt and penetrating thoracic trauma, this article outlines an approach to management for injuries to the lung, heart, esophagus, tracheobronchial tree, diaphragm, and major thoracic vessels. Also outlined are the management of rib fractures, scapula fractures, sternal fractures, and, in particular, flail chest with associated pulmonary contusion.

Aorta, Thoracic↗