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Biomedical subjects

J B Mark

Publications and source records attributed to J B Mark.

At least 73 records · Page 4Linked to original sources
PubMed1987

Nitrous oxide for blood pressure control after coronary artery surgery: a dose-response hemodynamic study in postoperative patients.

The inhaled anesthetic nitrous oxide is used for sedation in the coronary care unit and has been advocated as an antihypertensive agent in patients after a cardiac operation. To delineate the hemodynamic effects of nitrous oxide after cardiac surgery, we studied 11 patients with a mean age of 63 years who had undergone isolated coronary artery bypass grafting. All patients had major coronary artery disease and normal preoperative hemodynamic function. When patients were in stable condition in the intensive care unit, hemodynamic measurements were made at an inspired oxygen concentration of 40% with progressive doses of nitrous oxide (0, 10, 20, 40, and 60%). Measured and calculated hemodynamic data were compared using analysis of variance. Nitrous oxide caused significant decreases in mean arterial pressure in a dose-related fashion; pressure fell 6 mm Hg at 10% nitrous oxide and 11 mm Hg at 60% nitrous oxide (6 and 13% decreases). These changes were not associated with significant alteration in pulmonary artery pressure or cardiac index. Left ventricular stroke work index decreased significantly with the administration of nitrous oxide. We conclude that, in patients with normal hemodynamic and ventricular function, the administration of nitrous oxide for its sedative and antihypertensive effects is safe in the postoperative period and may be useful, especially in patients who are candidates for early extubation.

Aged↗
PubMed1987

Thoracic surgery manpower: the fourth manpower study of thoracic surgery: 1985 report of the Ad Hoc Committee on Manpower of The American Association for Thoracic Surgery and The Society of Thoracic Surgeons.

Responding to a survey about their practice in 1985, 2,969 (70%) Board-certified thoracic surgeons provided data that were compared with data from manpower surveys in 1980 and 1976. (table; see text) Thoracic surgeons were most active between ages 35 and 54 years when they accomplished 61% of all general thoracic and 85% of cardiac operations. Surgeons older than 50 years performed significantly more general thoracic operations than younger surgeons, and the younger group performed significantly more cardiac operations than their older counterparts. Solo practice continued to decline. In smaller referral areas, the number of general thoracic procedures per surgeon increased, but the number of cardiac operations have decreased compared with 1980. Overall, general thoracic and cardiac operations increased, but peripheral vascular procedures and pacemaker insertions decreased in almost all nine census regions. Fewer general thoracic and cardiac operations were performed per thoracic surgeon in the western United States than in central and eastern regions. In response to questions about work load, 55% believed that their clinical activity was satisfactory, 42% operated too little, and 3% operated too much. The 363 non-Thoracic Board-certified surgeons who responded performed 14% of general thoracic and 8% of cardiac surgery in 1985. During the first half of the 1980s, our specialty certified an average of 134 thoracic surgeons annually, which is higher than the 120 surgeons per year estimated to meet the projected demand.

Adult↗
PubMed1987

Reoperation for coronary artery bypass grafting: anesthetic challenge.

The problem of caring for patients undergoing reoperative coronary revascularization is one that cardiac anesthesiologists will face with increasing frequency. Many thousands of CABG procedures continue to be performed annually with ever-increasing survival rates. Consequently, the population at risk for reoperative CABG is growing, while surgical intervention necessarily follows apace. As one recent long-term, retrospective study showed, patients surviving 12 years after CABG have a reoperative rate of 17.3%. Physicians caring for these patients must recognize that they are not seeing patients with routine CAD, but with a different entity: coronary graft disease (CGD). These patients with CGD are different in many ways from those with native CAD, and these differences must be taken into account when planning for their perioperative care. Cardiologists have strived to check the growth of CGD by aggressive emphasis on modification of coronary risk factors such as tobacco use, hypertension, and hyperlipidemia. In addition, recent interest has been focused on a pharmacologic approach via the platelet-prostaglandin system. Surgeons have also attempted to reduce the incidence of CGD by recognition that significantly improved long-term patency rates can be achieved by the use of the internal thoracic artery as a bypass conduit. Consequently, an expanded role for this vessel in the form of free, sequential, and bilateral ITA grafting is currently being advocated as a surgical solution to the problem of CGD. In contrast, the anesthesiologist probably has little to add to the prevention of CGD, but may be able to contribute to a favorable outcome at reoperation. The medical variables and preoperative characteristics that make reoperative CABG patients different from those presenting for primary CABG should be recognized. A firm appreciation of the nature of graft disease, as well as the surgical intricacies required for correction, can only serve to improve the care offered during these often complex operations. Aggressive, invasive hemodynamic monitoring, constant vigilance for signs of early ischemia, and preparedness for prebypass hemorrhage and postbypass ventricular dysfunction should be made. Furthermore, if anesthesiologists are to contribute to an improved outcome in these patients, strategies must be developed to attenuate cerebral and myocardial damage resulting from hemorrhage and atheroembolic catastrophies that appear to be frequent complications in these challenging surgical patients.

Anesthesia, General↗
PubMed1987

Esophageal carcinoma: modest benefits from combined modality therapy.

Between 1969 and 1986, 109 consecutive patients with esophageal carcinoma were studied. Of the 77 patients who had squamous cell carcinoma, 62 received definitive treatment for disease confined to the esophagus and regional nodes. Survival was equivalent whether they were treated with radiation alone (n = 18), preoperative radiation and esophagectomy (n = 19), postoperative radiation (n = 5), or a combination of chemotherapy and radiation with or without esophagectomy (n = 20). Fifteen patients had significantly poorer survival after palliative irradiation for overt metastatic disease or severe debility. The pathologic specimens from four of the nine patients who underwent resection showed no histologic evidence of residual tumor; however, tumor recurred in three in the mediastinum, and only one remains alive and free of disease. Four of the 11 patients who received chemotherapy and radiation therapy without resection remain alive and free of disease after further mediastinal irradiation, suggesting a benefit from additional regional therapy. Chemotherapy improved median survival duration and complete response rate but did not produce a significant improvement in survival, as reported in other recent series.

Adenocarcinoma↗
PubMed1986

Continuous noninvasive monitoring of cardiac output with esophageal Doppler ultrasound during cardiac surgery.

Esophageal Doppler ultrasonography offers a continuous and noninvasive alternative to standard thermodilution cardiac output monitoring. A total of 372 simultaneous measurements of Doppler and thermodilution cardiac output were compared in 16 patients undergoing cardiac surgery. In addition, echocardiographic aortic diameter measurement, necessary for Doppler calibration, was compared with direct surgical measurement in 23 patients. Echocardiographic aortic measurement was often time consuming and correlated poorly (r = 0.31) with surgical measurement. On the other hand, Doppler cardiac output was determined easily and accurately tracked thermodilution cardiac output (R2 = 0.95, common slope coefficient 1.050, by multiple linear regression). Furthermore, Doppler cardiac output was more reproducible, showing less short-term variability than thermodilution cardiac output. The esophageal Doppler technique allows cardiac output monitoring in patients for whom invasive monitoring is not warranted.

Adult↗
PubMed1985

Open lung biopsy in patients with acute leukemia.

The results of open lung biopsy in 15 patients with acute leukemia, pulmonary infiltrates, neutropenia, and fever were reviewed. The patients averaged 26 hospital days of neutropenia and 20 hospital days of fever before open lung biopsy, and all patients received broad-spectrum antibacterial agents (mean 17 days) before open lung biopsy. Nine (67 percent) received amphotericin B prior to open lung biopsy (mean 22 days). Open lung biopsy yielded a specific clinically helpful diagnosis in six patients, but only two of these patients survived the hospitalization during which open lung biopsy was performed. Open lung biopsy detected fungus in four patients and leukemic infiltrates in two patients. Management was appropriately modified in these patients. In nine patients, a specific diagnosis of the pulmonary infiltrate was not obtained by open lung biopsy. Antimicrobial regimens were not changed substantially for these patients. In six patients, the results of open lung biopsy may have been misleading. Two patients had pulmonary fungal diseases at autopsy, undetected by open lung biopsy eight days and five weeks prior to death. Another patient had invasive aspergillosis and one had cytomegalovirus pneumonitis not detected by open lung biopsy. Two patients had false-positive preliminary histologic reports of pulmonary infection. On the basis of this experience, in this specific population of patients, open lung biopsy was often of little help in directing medical therapy or influencing clinical outcome.

Adolescent↗
PubMed1985

Combined laser therapy and endobronchial radiotherapy for unresectable lung carcinoma with bronchial obstruction.

Over a 4 year period, we refined a protocol for treatment of airway obstruction due to recurrent lung carcinoma. Patients undergo bronchoscopy with the Nd:YAG laser available on standby. If bronchial obstruction is found to be due to extrinsic compression, an endobronchial catheter is inserted for iridium 192 brachytherapy, treating a cylindrical volume 7.5 to 15 mm in radius. If an endobronchial lesion is found, the presence of complete versus partial bronchial obstruction determines the course of treatment. Total airway obstruction is treated with the laser until a channel is created and then an endobronchial catheter is placed for adjuvant endobronchial radiotherapy to treat a cylindrical volume 5 mm in radius. Partial airway obstruction is treated with an endobronchial catheter and radiotherapy alone. Segmental obstruction is also treated with a distally placed endobronchial catheter instead of the laser. Using this protocol, we hope to minimize risk to the patient by restricting the use of the laser with its inherent higher potential rate of complications to cases of total obstruction. In addition, we expect to prolong the duration of palliation with endobronchial radiotherapy. The laser is an excellent tool to reopen occluded bronchi, but it is relatively ineffective in producing long-term tumor control. Instead, we have found that placement of a temporary transtracheal endobronchial catheter for radiotherapy is a simple, low-risk procedure that can be safely performed even in critically ill patients. The endobronchial catheter can provide good to excellent long-term palliation for patients with both partially and totally obstructed endobronchial lesions or malignant extrinsic compression of major airways.

Airway Obstruction↗
PubMed1985

Bronchoscopy after cardiopulmonary transplantation.

Eighteen combined heart and lung transplant operations were performed between March, 1981, and March, 1984. Six of these patients have undergone bronchoscopy, at varying intervals after transplantation. Five of these procedures were done for specific clinical indications; one was done incidentally, during another surgical procedure requiring general anesthesia. All patients had intact, healing tracheal anastomotic suture lines; there were no instances of tracheal stenosis. The distal tracheobronchial tree appeared endoscopically normal in the transplanted lungs, except in areas of known infiltrates. Four of the patients had endobronchial biopsies, and alveolar eosinophilic proteinaceous exudate and submucosal mononuclear infiltrate were consistent features. Two of the later biopsies suggest that squamous metaplasia of the respiratory epithelium may occur with long-term follow-up. Controversy exists as to the optimal technique for tracheal anastomosis, but in the case of the steroid-treated, immunosuppressed transplant patient, continuous anastomosis with polypropylene has yielded satisfactory results.

Bronchi↗
PubMed1985

Treatment of bronchopleural fistula after pneumonectomy.

Breakdown of the closure of the main-stem bronchus after pneumonectomy is a dreaded complication, and empyema and bronchopleural fistula frequently develop in patients who survive. Management of these fistulas remains a formidable therapeutic challenge, which has been approached with a variety of surgical techniques. We report our experience with anterior transpericardial closure, emphasizing the ability to expose either main-stem bronchus by this approach. The case histories of three patients who had bronchopleural fistula after pneumonectomy are presented. The first patient had left pneumonectomy for complicated tuberculosis; the second had right pneumonectomy for neoplasm; and the third had right pneumonectomy for trauma. All fistulas were treated surgically via a median sternotomy and transpericardial approach to the distal trachea. The posterior pericardium was divided between the superior vena cava and aorta. In-continuity staple closure (with two lines of staples) of the proximal main-stem bronchus was employed in all cases. Two patients remain clinically well 21 and 17 months after the operation. The third patients did well initially but developed a recurrent bronchopleural fistula 2 1/2 months after the operation and has required repeat closure with pedicled muscle flaps. In postpneumonectomy bronchopleural fistula, the anterior, transpericardial approach to bronchial closure has several advantages: the relatively well-tolerated median sternotomy, the avoidance of dealing directly with areas of postoperative scarring and the devascularized bronchial stump, the avoidance of areas of chronic sepsis, and the avoidance of thoracoplastic surgical deformity of the chest wall, with possible associated compromise in pulmonary function. Our experience also indicates that either main-stem bronchus is accessible through an approach between the superior vena cava and aorta, without division of either pulmonary artery.

Adult↗
PubMed1984

The extent of surgery after chemotherapy for advanced germ cell tumors.

The histopathological findings of tissue removed from 40 patients with a residual mass after completion of induction chemotherapy with cis-platinum, vinblastine and bleomycin are reviewed. These patients with advanced testicular cancer were treated with chemotherapy until normalization of tumor markers and until there was no further decrease in the size of palpable or radiologically evident masses for 2 successive cycles of chemotherapy. The mean number of chemotherapy cycles preoperatively was 5.2. Residual carcinoma was found in only 1 patient (3 per cent), teratoma in 18 (45 per cent), and fibrotic and/or necrotic masses in 21 (52 per cent). With this tailored treatment regimen in which an operation is performed after maximal chemotherapeutic response, the number of patients with viable residual tumor at operation can be minimized. Complete retroperitoneal lymph node dissection concomitant with resection of the residual mass was performed in 22 of 32 patients with residual masses in the retroperitoneum. The 1 patient with carcinoma in the mass also had carcinoma in several of the lymph nodes, and 4 of the 11 with teratoma in the mass had teratoma in the lymph nodes. Since the histopathological findings of the mass often parallel those of the lymph nodes, and since masses containing only fibrosis and/or necrosis cannot be ascertained with accuracy at operation, a complete retroperitoneal lymph node dissection is recommended in patients with a residual retroperitoneal mass.

Adolescent↗
PubMed1984

Therapeutic thoracoscopy.

Thoracoscopy was originally devised for diagnostic purposes but has subsequently come to have several therapeutic applications as well. This report reviews our experience with 13 patients in whom thoracoscopy was used in a therapeutic capacity. In three patients intrapleural foreign bodies (segments of polyethylene catheters) were removed endoscopically. In two patients open postpneumonectomy empyema cavities were explored and debrided thoracoscopically. In the remaining eight patients thoracoscopy was used to facilitate chemical pleurodesis in the treatment of effusions or pneumothoraces, after resectable disease had first been ruled out. Our conclusions are as follows: (1) Thoracoscopy can serve therapeutic as well as diagnostic functions. (2) Excellent exposure can be obtained during general anesthesia by use of one-lung ventilation. (3) Thoracoscopy is a safe, simple, and effective means of removing intrapleural foreign bodies. (4) Thoracoscopy allows chemical pleurodesis to be applied selectively to patients who will not require future thoracotomy; i.e., those with proved incurable malignant disease or with recurrent pneumothoraces without gross abnormalities of the pulmonary parenchyma. (5) Chemical pleurodesis is facilitated by this technique, which assures uniform exposure of all pleural surfaces to the sclerosing agent. (6) Pleurodesis is less painful when the sclerosing agent is introduced during general anesthesia. (7) Thoracoscopy allows safe, complete, visually guided débridement of open postpneumonectomy empyema cavities.

Adult↗