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Biomedical subjects

F L Grover

Publications and source records attributed to F L Grover.

At least 163 records · Page 9Linked to original sources

Is a left ventricular vent necessary during cardiopulmonary bypass?

This study evaluated the coronary flow and the internal diameter, pressure, and metabolism of the left ventricle using four different cardiopulmonary bypass techniques. Conditioned dogs underwent a 30-minute stabilizing period on cardiopulmonary bypass with a beating, empty heart (normothermia and a flow of 80 ml/kg/min). They were then fibrillated and subjected to four experiments: Group A (7 dogs)--left ventricular vent, caval tapes open; group B (7 dogs)--left ventricular vent, caval tapes closed; group C (7 dogs)--no vent, caval tapes open; group D (4 dogs)--no vent, caval tapes closed. There was no major difference in any of these variables among Groups A and B (both ventricles vented). Group D (no vent, tapes closed) had significantly increased wall tension, decreased coronary flow, decreased subendocardiac flow, and ischemia. In contrast, Group C dogs (no vent, tapes open) had only a slight increase in left ventricular diameter and pressure, with no change from Group A and B dogs in coronary flow, lactate extraction, hydrogen ion production, or potassium difference. Therefore, venting the fibrillating ventricle, either with or without snaring of the caval tapes, is probably the best method to use during the distal anastomosis in a coronary artery bypass operation. However, if a vent is not used, the caval tapes should be left open to allow complete diversion of the venous blood and decompression of the left ventricle.

Animals↗

Subxiphoid pericardial window in patients with suspected traumatic pericardial tamponade.

The technique, indications, and results of subxiphoid pericardial window in penetrating chest wounds with suspected traumatic pericardial tamponade are reported. The classic signs of pericardial tamponade (elevated central venous pressure, muffled heart sounds, and paradoxical pulse) are unreliable in an emergency situation. Chest roentgenograms and electrocardiograms are of little diagnostic value. Pericardicentesis was either falsely positive or negative in 50% of our patients. Therefore, unexplained high central venous pressure and hypotension were considered to be pericardial tamponade until disproved by the results of a subxiphoid pericardial window. There were 4 negative and 46 positive findings of tamponade in 50 consecutive patients with suspected traumatic pericardial tamponade who underwent creation of a subxiphoid pericardial window. There were no deaths or complications from the procedures. The early use of subxiphoid pericardial window has been a major factor in reducing our mortality rate from penetrating heart wounds to 12% overall, and 8% in the past three years.

Blood Pressure↗

Subxiphoid anterior mediastinal exploration.

A new surgical technique for anterior mediastinal exploration is described. The technique involves application of a Carlens mediastinoscope by means of a subxiphoid incision. The procedure provides complete exploration of the anterior mediastinal compartment and allows the surgeon to obtain a positive biopsy of the tumor or its lymph node metastases without sternotomy.

Anesthesia, General↗

Posttraumatic empyema.

This is a report of the experience gained from treating 18 patients with posttraumatic empyema during a 36-month period. The objectives of treatment were twofold: complete reexpansion of the lung, and evacuation of infected foreign material from the pleural space. The techniques of achieving these objectives were tube thoracostomy initially, followed by early thoracotomy if necessary.

Adult↗

Effects of ventricular fibrillation on coronary blood flow and myocardial metabolism.

Ventricular fibrillation is frequently induced during cardiac surgery to quiet the operative field. The reported effects of fibrillation on the myocardium vary considerably. In an attempt to better define these effects, we subjected 28 dogs to one hour of total normothermic bypass. Myocardial blood flow, lactate, adenosine triphosphate (ATP), oxygen consumption, and left ventricular fibrillation was induced in 5 dogs and continuous electrical fibrillation in 7 dogs. These groups were compared to two respective control groups with beating hearts of 8 animals each. Coronary sinus flow, total coronary blood flow, left ventricular flow, myocardial oxygen consumption, and myocardial tissue lactate increased significantly in the fibrillating hearts. Left ventricular dp/dt decreased with fibrillation, but not significantly. It is concluded that the metabolic demands of ventricular fibrillation exceed the increase in coronary blood flow, when compared to demands of the beating heart, and that decreased left ventricular performance may result.

Adenosine Triphosphate↗

Prophylactic antibiotics in the treatment of penetrating chest wounds. A prospective double-blind study.

Considerable controversy exists as to whether or not antibiotics should be administered "prophylactically" to patients with penetrating chest trauma. No prospective study of this problem has been reported. Therefore, 75 patients with isolated, penetrating chest injury were randomized prospectively in a double-blind study. Group A patients (38 patients) were given 300 mg. of clindamycin phosphate every 6 hours, beginning with admission and lasting until 1 day following chest tube removal or for 5 days, whichever was shorter. Group B patients (37 patients) were given a placebo on the same schedule. The patients' hospital course, fever, white blood count, culture data, and roentgenograms were recorded serially. Clindamycin-treated patients had a significantly lower incidence of radiographic pneumonia, less fever, and a lower incidence of positive pleural and wound cultures. They acquired empyema less frequently, required fewer operations, and had a shorter period of hospitalization. Antibiotics may be useful, therefore, as adjunctive therapy in the management of penetrating chest trauma.

Adolescent↗

Effects of methylprednisolone on coronary blood flow and myocardial metabolism during cardiopulmonary bypass.

Corticosteroids frequently are used during cardiopulmonary bypass (CPB) to enhance total body perfusion and myocardial preservation. The mechanisms by which steroids might provide protection to the myocardium have not been clearly defined, however. Therefore this study was performed to measure the effects of methylprednisolone (M-P) on coronary flow and distribution, and on myocardial metabolism and contractility. Twenty-three dogs underwent 1 hour of total CPB, 80 cc/kg/minute at normothermia with beating hearts. Alternate animals received M-P, 30 mg/kg. Myocardial blood flow (microspheres technique), myocardial tissue lactate and adenosine triphosphate, lactate extraction, coronary sinus flow (CSF), and coronary vascular resistance (CVR) were measured before, during, and 60 minutes after bypass. LV dp/dt and cardiac output (CO) were measured before and after bypass. Total coronary flow was significantly higher in the M-P group after 10 and 30 minutes of bypass (93 vs 56 ml/100 gm/minute, p less than 0.05, and 96 vs 71 ml/100 gm/minute, p less than 0.05). Right ventricular flow was higher in the M-P group at 10 and 30 minutes of bypass (98 vs 66 ml/100 gm/minute, p less than 0.05, and 90 vs 78 ml/100 gm/minute). Left ventricular flow was higher in the M-P group at 10 minutes of bypass (79 vs 52 ml/100 gm/minute, p less than 0.08). Septal flow also was higher in the treated group at 10 minutes of bypass (64 vs 49 ml/100 gm/minute) and at 30 minutes of bypass (92 vs 67 ml/100 gm/minute, p less than 0.05). CVR after 10 minutes of bypass was lower in the steroid group (88 mm Hg/ml/100 gm/minute vs 1.39 in the control group, p less than 0.03). It is concluded that M-P increases coronary blood flow and decreases CVR in the empty beating heart during normothermic CPB without altering myocardial metabolism or contractility.20

Adenosine Triphosphate↗

Transthoracic approach for Pott's disease.

Spinal tuberculosis with paraplegia, although decreasing in incidence, remains a problem in certain sections of the United States and in most underdeveloped nations. Evacuations of the tuberculous abscess, debridement of necrotic bone, and fusion of the anterior spine are maneuvers performed increasingly by thoracic surgeons. Twenty-two patients with Pott's disease and symptoms of back pain, gibbous deformity, and neurological deficit underwent thoracotomy. Nine were paraplegic prior to operation. Postoperatively, spinal fusion occurred in all cases. All paraplegic patients can walk now, and 17 of the 22 treated operatively have been completely rehabilitated and are in school or working. The average hospital stay was 2.4 months. There was 1 operative death. Medical treatment for Pott's disease consisted of bed rest and chemotherapy and resulted in progressive neurological deficit in 2 patients with an average hospital stay of 2.2 years. We believe operative treatment offers two distinct advantages: excellent reversal of even long-standing paraplegia and markedly shortened hospital stay.

Adolescent↗

Effects of morphine and halothane anesthesia on coronary blood flow.

This study was undertaken to determine the relative effects of morphine and halothane anesthesia on coronary blood flow. Right heart bypass was instituted in 20 dogs by draining the vena cava blood into a cardiotomy reservoir and returning it to the main pulmonary artery. Coronary sinus drainage was measured by a right ventricular cannula. Group I (10 dogs) was sequentially given 0.5, 1, 1.5, 2.0, and 2.5% halothane. Group II (10 dogs) was given 1, 2, 3, 4, and 5 mg per kilogram of morphine intravenously. Arterial pressure, coronary sinus blood flow, cardiac output, arterial pH, PCO2, and PO2 were determined and repeated at each dose level of anesthesia and compared to the control values. Morphine significantly increased coronary flow at 3, 4, and 5 mg/kg without pressure adjustment and at 2 mg/kg after pressure adjustment. Coronary flow with halothane was unchanged from control values except for a decrease at 2.5%. Coronary flow was significantly greater with 3, 4, and 5 mg/kg of morphine than with 1.0 and 1.5% halothane.

Anesthesia, Inhalation↗

Blunt traumatic rupture of the atria.

The case histories of 2 patients with atrial rupture from blunt chest trauma are presented, one of whom is the tenth survivor. Based on a review of these cases and the literature, important factors in the diagnosis and treatment of this easily repairable anatomic lesion are discussed. The importance of rapid recognition and early operation are emphasized.

Adult↗

Fatal air embolism following gunshot wound of the lung.

Air embolism following penetrating lung trauma has been reported infrequently and its existence is questioned. A death resulting from air embolism following a high-velocity gunshot wound is presented. Appropriate treatment and preventive measures are discussed.

Adult↗

Management of flail chest without mechanical ventilation.

The pathophysiology of flail chest is usually described only on the basis of paradoxical respiration, ignoring underlying pulmonary contusion. Two groups of comparable patients were treated either with early tracheal intubation and mechanical ventilation (Group 1), or with fluid restriction, diuretics, methylpredinisolone, albumin, vigorous pulmonary toilet, and intercostal nerve blocks, ignoring the paradox and treating only the underlying lung (Group 2). When tracheostomy and mechanical ventilation were not used the mortality rate went from 21% to O(p = 0.01), the complication rate from 100% to 20% (p = 0.005), and the average hospitalization from 31.3 to 9.3 days (p = 0.005). We conclude that most patients with flail chest do not need internal pneumatic stabilization if the underlying lung is treated appropriately and that tracheostomy and prolonged mechanical ventilation with a volume respirator, as practiced in most respiratory care centers, is usually a triumph of technique over judgment.

Adolescent↗

Closed aortic valvotomy and simultaneous correction of associated anomalies in infants.

A small infant with severe congenital aortic stenosis presents a difficult therapeutic problem. Both operative and nonoperative treatment are hazardous--especially when other cardiovascular anomalies are present. This report describes a simple, effective technique for dilating the stenotic aortic valve and simultaneously repairing certain associated defects. The procedure has been used successfully in 3 infants with a postoperative follow-up of 6 months to 4 years. There were no deaths, and the functional results have been excellent. This technique is presented as an alternative to the more hazardous approach to open valvotomy and/or stage correction of associated anomalies.

Abnormalities, Multiple↗

Pulmonary sling. Case report and collective review.

The eighteenth survivor of correction of an anomalous left pulmonary artery arising from the right pulmonary artery is reported. This is the first case in which postoperative angiography demonstrated patency of the left pulmonary artery. The onset of symptoms in infancy, predominance of expiratory rather than inspiratory stridor, anterior indentation of the esophagus, and lethal progression of symptoms during the first year of life are peculiar to this anomaly. Operation through a left thoracotomy is advocated, with division of the proximal left pulmonary artery and implantation into the main pulmonary artery posterior to the phrenic nerve. Previously reported cases are collectively reviewed.

Angiography↗