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Biomedical subjects

F L Grover

Publications and source records attributed to F L Grover.

At least 109 records · Page 6Linked to original sources
PubMed1991

Comparison of a steady flow pump to a preload responsive pulsatile pump in left atrial-to-aorta bypass in canines.

A unique preload responsive pulsatile pump was compared to a centrifugal pump in total cardiac support in 25-kg canines (n = 6, each group) in the left atrial-to-aorta mode during 5 h of ventricular fibrillation. With steady flow, there was immediate drop in output from 2.1 +/- 1.0 L/min to 1.4 +/- 0.3 L/min, followed by further reduction to 0.9 +/- 0.2 L/min during 5 h of ventricular fibrillation. With a pulsatile pump, there was no significant reduction from control of 2.4 +/- 0.6 L/min and no decline during 5 h of ventricular fibrillation. With steady flow, systemic vascular resistance (SVR) rose significantly from 1,762 dyne-s-cm-5 immediately on pump to 3,013 dyne-s-cm-5 at 5 h. With physiologic pulsatile flow, significant elevation of SVR did not occur. When stressed, due to diminished left atrial return, the centrifugal pump displayed line chatter and streaks of microbubbles, whereas the pulsatile pump did not. Crystalloid volume replacement with the centrifugal pump was 6.5 +/- 1.9 L, and with the preload responsive pulsatile pump, 5.6 +/- 1.3 L. It is concluded that in the left atrial-to-aorta mode during 5 h of ventricular fibrillation and with comparable volume replacement, total cardiac support of canines is associated with lower SVR with physiologic pulsatile flow and is not accompanied by line chatter and cavitation with this preload responsive pump.

Animals↗
PubMed1991

Single lung transplantation. Alternative indications and technique.

Twenty-two patients have undergone 23 single lung transplants between March 1980 and April 1990 at the University of Texas Health Science Center at San Antonio. The actuarial survival rate is 77.27% at 12 months and 72.73% at 24 months. There have been no instances of bronchial dehiscence or stenosis, even though 13 of the patients were on a program of preoperative prednisone, every patient had high-dose perioperative methylprednisolone, and omental wraps were not used on any bronchial anastomosis. Of particular interest is the fact that three patients had primary pulmonary hypertension, three had secondary pulmonary hypertension, and 10 patients had chronic obstructive pulmonary disease, due in five cases to an alpha 1-antitrypsin deficiency. Each of these entities was previously thought to contraindicate single lung transplantation. Donor selection was based on an oxygen tension/inspired oxygen concentration ratio greater than 300, donor/recipient chest circumference within 3 inches, clear chest x-ray film, negative sputum Gram stain, and less than 6-hour estimated ischemic time. Harvest technique included donor prostaglandin E1 500 micrograms, topical slush, and pulmonoplegia with cold Euro-Collins solution. The heart and lung were separated in situ rather than the heart lung block being removed. A telescoping bronchial anastomosis was performed with 4-0 Prolene (not absorbable) sutures. We conclude that single lung transplantation has evolved into a simple operation, necessitating meticulous preoperative and postoperative care, which can be performed on a wide spectrum of critically ill patients with an acceptable mortality rate.

Adult↗
PubMed1990

Initial report of the Veterans Administration Preoperative Risk Assessment Study for Cardiac Surgery.

This study was authorized by the Department of Veterans Affairs to improve the quality assurance of cardiac surgery by assessing preoperative risk factors and relating them to operative mortality. Data were received on 10,480 patients over a 2-year period. Preoperative risk variables were subjected to univariate and multivariate logistic regression analyses. Significant variables for coronary artery bypass grafting after logistic regression analysis in order of importance are previous cardiac operation, priority of operation, New York Heart Association functional class, peripheral vascular disease, age, pulmonary rales, current diuretic use, and chronic obstructive pulmonary disease. For patients undergoing valve or other cardiac operations with or without coronary artery bypass grafting, those variables found to be significant after multivariate logistic regression analysis are priority of operation; age; peripheral vascular disease; great vessel repair; all other except aortic valve replacement, mitral valve replacement, and great vessel repair; mitral valve replacement; and cardiomegaly. By identifying these current risk factors and the coefficients from the multivariate stepwise logistic regression analysis, expected mortality can be calculated. We propose that the ratio of observed to expected mortality is a better measure of quality of care than unadjusted mortality.

Aged↗
PubMed1990

Right pneumonectomy syndrome in infancy treated with an expandable prosthesis.

Severe respiratory distress developed in a 5-month-old infant approximately ten days after pneumonectomy for complete sequestration of the right lung. Right pneumonectomy syndrome was diagnosed by bronchography, which revealed thinning and obstruction of the left main bronchus during expiration. A right thoracotomy was then performed, and an inflatable tissue expander with a subcutaneous injection port was inserted into the right chest cavity to prevent recurrence of the mediastinal shift and to allow for future growth. The patient has done well, requiring reinjection of the prosthesis with additional volume on one occasion in a 20-month period of follow-up.

Airway Obstruction↗
PubMed1990

Identification of patients at greatest risk for developing major complications at cardiac surgery.

As part of a prospective program to use risk-adjusted outcome (operative mortality and morbidity) as a measure of quality of care, we have analyzed perioperative complication data in 10,634 patients representing 73% of all patients undergoing cardiac surgery requiring cardiopulmonary bypass at Veterans Administration medical centers between April 1, 1987, and March 31, 1989. One or more complications occurred in 15% of patients undergoing coronary artery bypass grafting, and in 24% of patients undergoing valve and other cardiac surgery. Patients experiencing one or more complications had an eightfold to 10-fold increase in operative mortality compared with patients with no perioperative complications. The most frequent complication was requirement for mechanical ventilation for at least 48 hours occurring in 8% of patients undergoing coronary artery bypass and in 15% of patients undergoing valve and other cardiac surgery; 24-25% of these patients died within 30 days of surgery or as a direct result of a surgical complication. Previous heart surgery was a strong predictor of development of one or more complications in both groups of patients, being associated with an adjusted relative risk of 1.6-2.0. Other important predictors in both surgical groups were surgical priority, older age, peripheral vascular disease, and higher serum creatinine. Although a number of preoperative risk factors could be identified for the development of renal failure, low cardiac output, and requirement for prolonged mechanical support, few risk factors could be identified for the development of mediastinitis and reoperation for bleeding. This observation suggests that mediastinitis and reoperation for bleeding are more likely the result of technical factors rather than patient-related risk factors.

Cardiac Surgical Procedures↗
PubMed1989

Recurrence and survival following resection of bronchioloalveolar carcinoma of the lung--The Lung Cancer Study Group experience.

Bronchioloalveolar carcinoma (BAC) of the lung is a controversial form of adenocarcinoma with varying presentations. The 1977 to 1988 Lung Study Group experience with this tumor was reviewed to more precisely define the incidence of recurrence and survival of surgically resected and staged patients, to determine the incidence of BAC in the adenocarcinoma population, and to evaluate the impact of age, sex, smoking, and chronic lung-disease history on the incidence of BAC. Of 1635 patients reviewed, 235 patients had pure BAC. It was found that resectable BAC presents at an earlier disease stage than does adenocarcinoma; BAC occurs more frequently in older patients and in those without smoking history or chronic lung disease than adenocarcinoma; BAC patients have less weight loss, brain recurrences, and recurrences without second primaries than adenocarcinoma; survival and recurrence-free survival are better for BAC than for non-BAC adenocarcinoma and large-cell carcinoma; early BAC survival is better than squamous-cell survival but after 2 years is equivalent; T1-N0 BAC patients have recurrence and survival rates similar to squamous-cell survival rates and better than non-BAC adeno survival rates; T1-N1/T2-N0 and Stage 2 and 3 BAC recurs more frequently than either squamous-cell or non-BAC adenocarcinoma; stage 2 and 3 BAC has a higher mortality rate than does squamous-cell carcinoma or non-BAC adenocarcinoma; BAC is a favorable prognostic factor when adjusted for extent of disease and age; and BAC's better prognosis is a result of presenting at an earlier stage of disease and because it appears to be less aggressive than other adenocarcinomas even after adjustment for extent of disease and other known prognostic factors. It is concluded that early diagnosis and resection are particularly important for patients with BAC.

Adenocarcinoma↗
PubMed1989

Preload-responsive, pulsatile-flow, externally valved pump: cardiopulmonary bypass.

Currently two pumps are used for cardiopulmonary bypass, the roller pump and the centrifugal or vortex pump. Both are steady-flow pumps. The procedure of cardiopulmonary bypass possesses a finite morbidity and mortality. The degree to which steady flow is responsible for this morbidity and mortality remains to be clarified, but investigators have established the fact that a physiologic degree of pulsatile flow must be achieved before its beneficial results, such as normal systemic resistance and absence of lactate production, can be demonstrated. Availability of a satisfactory pulsatile pump for cardiopulmonary bypass has been a problem in the past but the pump presented here may satisfy this need. It produces physiologic pulsatility with rate dependent ejection time equal to or less than that of humans (413 microseconds minus 1.7 times heart rate), and it is preload-responsive, varying its pumping rate and output with filling pressure. The pump is externally valved to minimize hemolysis, which has been demonstrated in two laboratory studies to be significantly less than with the roller pump. It produces pulsatile flow through membrane oxygenators. The pump is thought to have potential for several clinical applications in addition to (1) pulsatile-flow cardiopulmonary bypass, including (2) left, right, or combined transthoracic QRS synchronized ventricular assist, (3) femoral vein to femoral artery QRS synchronized left ventricular assist, (4) adult or infant ECMO, (5) pulsatile flow hemodialysis. In the latter, spallation and embolization of hemodialysis tubing particles should not be a problem as has proved to be the case with the present hemodialysis pump.

Cardiopulmonary Bypass↗
PubMed1988

Report of the Ad Hoc Committee on Risk Factors for Coronary Artery Bypass Surgery.

The Society of Thoracic Surgeons remains greatly concerned about the use of raw mortality data as the sole measure to determine quality of care following coronary artery bypass surgery. Use of such data without consideration of risk factors that are predictors of hospital mortality and of other indices of quality of care is inappropriate and misleading and may adversely affect the care of the high-risk cardiac surgical patient. The Society is committed to the principle of providing the public with accurate information regarding the conduct of coronary artery surgery. However, it believes that the data provided by HCFA do not provide this information and should not be used as the sole index of quality of care following coronary artery bypass surgery.

Coronary Artery Bypass↗
PubMed1988

Complement and neutrophil activation in the pathogenesis of ischemic myocardial injury.

Complement depletion with cobra venom factor (CVF) before coronary artery ligation has been previously shown to reduce subsequent ischemic myocardial tissue injury in the baboon; however, whether complement depletion after the initiation of acute myocardial ischemia affords similar myocardial preservation is not known. Both complement depletion with CVF or the administration of certain nonsteroidal anti-inflammatory drugs, including ibuprofen, are thought to decrease myocardial infarct size by reducing polymorphonuclear leukocytic (PMN) infiltration; nevertheless, complement activation also could alter tissue injury by PMN-independent actions. Thus, the relative effects of CVF administered after coronary artery ligation on the subsequent development of myocardial tissue injury were assessed in a baboon myocardial infarction model. The animals were randomized into three treatment groups (n = 6): either CVF (125 units/kg) or saline was given 30 minutes after coronary artery ligation, and ibuprofen (12.5 mg/kg) was administered 30 minutes and 4 hours after ligation. The extent of ischemic myocardial injury was assessed 24 hours later. Relative to saline-treated baboons, both CVF and ibuprofen reduced PMN infiltration (36 +/- 4 vs. 24 +/- 4 and 24 +/- 4 PMN/mm2, respectively; mean +/- SEM) and histological evidence of transmural myocardial infarction (100% vs. 47% and 53%, respectively) in electrocardiographically designated, expected infarct sites. In both saline- and ibuprofen-treated animals, there was extensive localization of C4, C3, and C5 in all infarct sites; in contrast, there was only C4 localization in the CVF-treated baboons. When expected infarct sites were assessed for creatine kinase content as an indicator of tissue injury, there was significantly less epicardial and endocardial creatine kinase depletion in the CVF-treated animals (31.7 +/- 5.6% and 39.3 +/- 4.8%) than in the saline-treated animals (54.1 +/- 5.4% and 59.0 +/- 4.7%; p = 0.012 and 0.011, respectively). The percent creatine kinase depletion in the ibuprofen-treated animals was intermediate between the two other groups. These results suggest that depletion of complement after coronary ligation has beneficial effects in reducing tissue injury that cannot be explained solely on the basis of reducing PMN infiltration into the ischemic myocardium.

Animals↗
PubMed1988

Management of penetrating lung injuries in civilian practice.

Recent reports of military thoracic injuries have advocated early thoracotomy and aggressive management of pulmonary injuries with resection as opposed to the more conservative and traditional treatment with chest tube thoracostomy. A retrospective study was therefore performed to determine the incidence of thoracotomy and lung resection in civilian injuries and to evaluate the effectiveness of treatment of these injuries. Between 1973 and 1985, in a series of 1,168 patients, there were 384 gunshot wounds and 784 stab wounds to the thorax. Two hundred eighty-three patients with a gunshot wound (74%) and 602 with a stab wound (77%) were treated with chest tubes alone. Sixty-eight patients (6% of the total) required operative repair of pulmonary hilar or parenchymal injury. Pulmonary resection was necessary in only 18 patients (nine with a gunshot wound and nine with a stab wound), and 10 patients had repair of hilar injuries (nine with a gunshot wound and one with a stab wound). Of patients requiring pulmonary resection, nine required wedge or segmental resection, six required lobectomy, and three patients required pneumonectomy. Mortality for all thoracic injuries was 2.3%: for those treated with chest tube alone, 0.7%; for pulmonary hilar injuries, 30%; for pulmonary parenchymal injuries, 8.6%; and for injuries necessitating lung resection, 28%. Most civilian lung injuries can be treated by tube thoracostomy alone. Although relatively few patients with primary pulmonary injury require thoracotomy, those that do are at significant risk and may require lung resection to control bleeding or hemoptysis or to remove destroyed or devitalized lung tissue.

Adolescent↗
PubMed1987

Standard biplane roentgenography is highly sensitive in documenting mediastinal masses.

The records of 30 patients with mediastinal masses were reviewed to evaluate the signs, symptoms, and preoperative tests that were most useful in diagnosing and localizing the masses. Sixteen (53%) of the tumors were benign, and 14 (47%) were malignant. Twenty patients were seen with symptoms. The most common symptoms suggesting malignancy were pain, weight loss, fever, and cough. Four of the 5 patients who were truly asymptomatic had benign lesions. All 4 patients with palpable adenopathy had malignant tumors. Posteroanterior and lateral chest roentgenograms detected the mediastinal mass in 29 (97%) of the 30 patients. All patients were operated on for tissue diagnosis or resection (13, median sternotomy; 8, right thoracotomy; 3, left thoracotomy; 2, low anterior cervical approach). Eight patients underwent mediastinoscopy, which was diagnostic in 6 and obviated the need for operation in 4. It was of particular value for patients with lymphoma, who can be managed without resection.

Adult↗
PubMed1986

Operative closure of patent ductus arteriosus in premature infants in the neonatal intensive care unit.

Fifty-two premature infants underwent hemoclip closure of patent ductus arteriosus in the neonatal intensive care unit after a brief trial of fluid restriction and diuretics. Indomethacin was used in only four patients. The median time from diagnosis to operation was 3 days. There were no deaths directly attributable to operation. Nine operative complications developed in nine patients (17 percent). There were no surgical infections. Complications related to prematurity resulted in 20 deaths (38 percent). Patent ductus arteriosus closure in the neonatal intensive care unit prevented the complications of hypothermia, inadvertent extubation, and interruption of vascular access and monitoring. Early operative closure in the neonatal intensive care unit is the treatment of choice in most premature infants with patent ductus arteriosus.

Ductus Arteriosus, Patent↗
PubMed1986

Comparison of the cardiovascular effects of intravenous and intraaortic protamine in the conscious and anesthetized dog.

Controversy exists as to whether intraaortic (IA) administration of protamine sulfate has less adverse effects than the intravenous (IV) route. The effect of protamine on contractility is not well established. Therefore, 9 dogs underwent chronic instrumentation to monitor aortic pressure (AP), left ventricular (LV) pressure, central venous pressure, cardiac index (CI), heart rate, stroke volume index (SVI), systemic vascular resistance index, and LV volume. The end-systolic LV pressure-volume relationship was used as a load-independent measure of contractility. Each dog was administered IV and IA protamine on separate occasions after pretreatment with heparin. Studies were performed with and without anesthesia. In the awake studies, analysis of variance showed greater decreases in mean AP (p less than .03), CI (p less than .05), and SVI (p less than .02) with IA protamine infusion. In the anesthetized animals, there were no significant differences between IA and IV administration of protamine. Protamine did not decrease contractility in any group. We conclude that IA administration of protamine offers no advantage over IV administration in the dog. Protamine does not decrease contractility when given by either route.

Analysis of Variance↗
PubMed1986

Management of blunt rupture of the heart.

Ten patients with blunt heart rupture arrived in our emergency center alive during an 11-year period ending in 1984. Ages ranged from 19 to 65 years (mean, 35), and seven patients were male. Six patients presented with tamponade, three with hemorrhagic shock, and one with combined symptoms. Associated injuries averaged 2.25 organ systems per patient. All but one patient had surgery within 90 minutes of arrival. All patients had primary closure of the defect without cardiopulmonary bypass, five patients had subxiphoid window followed by sternotomy, two had right thoracotomy, two underwent left thoracotomy, and one patient was subjected to immediate sternotomy. Seven patients survived. Three deaths were due to irreversible hemorrhagic shock, two secondary to heart injury, and one from an associated liver injury. Prompt pericardial window with subsequent median sternotomy was successful for patients presenting with tamponade and immediate thoracotomy for those bleeding into a pleural cavity.

Adult↗
PubMed1985

Effects of varied cardioplegic perfusion pressure on myocardial preservation with critical coronary stenosis.

Inadequate delivery of cardioplegic solution distal to coronary artery stenosis may result in increased injury during ischemic arrest. This study was performed to determine the effects of cardioplegic perfusion pressure on cardioplegia delivery and myocardial preservation in hearts with critical coronary artery stenosis. Twenty dogs underwent 90 minutes of cold potassium cardioplegic arrest with partial occlusion of the circumflex coronary artery. Group 1 received cardioplegia at 50 mm Hg pressure, Group 2 at 90 mm Hg pressure, and Group 3 at 130 mm Hg pressure. It was found that cooling rates were 5.4 degrees, 9.1 degrees, and 18.2 degrees C per minute in the nonischemic area (p = 0.004) and 2.0 degrees, 4.5 degrees, and 7.9 degrees C in the ischemic area (p = 0.008) in Groups 1, 2, and 3, respectively. Total of cardioplegic solution flows were 86, 188, and 262 ml per minute per 100 gm in Groups 1, 2, and 3, respectively (p = 0.001). However, flow did not differ significantly between groups in the ischemic area. Rate of rise of left ventricular (LV) pressure decreased significantly in Groups 1 and 2 but not in Group 3 (p = 0.002). Other measured variables did not differ significantly between groups, although LV function curves showed less deterioration in the high-pressure groups. It is concluded that higher cardioplegic perfusion pressure resulted in more rapid cooling in normal and ischemic areas and slightly better preservation of ventricular function as measured by some indexes. However, preservation was generally good for each of the pressures for up to 90 minutes of ischemia when the septum was consistently cooled to 10 degrees C.

Adenosine Triphosphate↗