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Biomedical subjects

G M Graeber

Publications and source records attributed to G M Graeber.

At least 55 records · Page 3Linked to original sources
PubMed1990

Alterations in serum creatine kinase and lactate dehydrogenase. Association with abdominal aortic surgery, myocardial infarction and bowel necrosis.

Experimental studies have shown that peripheral serum creatine kinase and lactate dehydrogenase change with bowel infarction. Some clinical reports have suggested that similar changes occur in patients. This prospective study documents the changes in these enzymes associated with acute myocardial infarction, acute bowel necrosis (MES INF), and uncomplicated abdominal aortic reconstruction. Analysis of 15 patients with AMI, 13 patients undergoing major AAS, and eight patients with MES INF has shown that these conditions may be differentiated by analysis of serum CK and LD isoenzymes. The study suggests that in the absence of electrocardiographic changes, a patient with epigastric distress with elevated levels of serum CK and either CK-MB or CK-BB bands present may well have a mesenteric rather than a myocardial infarction. Acute myocardial infarction can be ruled out further through analysis of serum LD1/LD2 ratios.

Aged↗
PubMed1990

A comparative evaluation of pulmonary artery balloon counterpulsation and a centrifugal flow pump in an experimental model of right ventricular infarction.

To compare the efficiency of pulmonary artery balloon counterpulsation and a centrifugal flow pump in reversing the hemodynamic consequences of acute right-sided heart failure, we employed both devices in 14 Yorkshire pigs in which right ventricular infarction was created via surgical ligation of branches of the right coronary artery. Pulmonary artery balloon counterpulsation improved some of the indicators of right heart failure, as manifested by significantly decreased right atrial pressure and increased mean systemic blood pressure. In contrast, the centrifugal flow pump consistently and significantly reversed all of the hemodynamic consequences of right ventricular infarction. In comparison to pulmonary artery balloon counterpulsation, the centrifugal flow pump resulted in lower right atrial pressures (p=0.020), lower mean pulmonary pressures (p less than 0.0001), increased left atrial pressures (p=0.026), increased cardiac output (p less than 0.0001), and increased mean systemic blood pressures (p less than 0.0001). Possible mechanisms to explain the superiority of the centrifugal flow pump include better hemodynamic unloading of the failing myocardium and independence from right ventricular output.

Animals↗
PubMed1989

Anaphylactoid reactions mediated by autoantibodies to cholesterol in miniature pigs.

Antoantibodies to cholesterol were detected and purified from normal (nonimmunized) pig serum. The antibodies were assayed by ELISA with crystalline cholesterol as an Ag and by C-dependent damage to cholesterol-laden liposomes. Intravenous injection of liposomes containing cholesterol into anesthetized animals caused decreased hemolytic complement titers, and induced a reaction consisting of transient neutropenia, thrombocytopenia, respiratory distress, cyanosis, pulmonary and systemic hypertension, and decreased cardiac output. Plasma levels of thromboxane B2 and 6-keto-prostaglandin F1 alpha increased 1300 and 200%, respectively, and leukocyte and platelet counts decreased by 36 and 38%, respectively. Injection of cholesterol-free liposomes did not induce the reaction. These results show that naturally occurring autoantibodies to cholesterol can initiate C activation and can be associated with anaphylactoid reaction to exogenously administered cholesterol in pigs.

Anaphylaxis↗
PubMed1989

Chest wall implantation of lung cancer after thin-needle aspiration biopsy.

Percutaneous aspirational biopsy of intrathoracic lesions has become a popular technique. One of the rarest complications is that of implantation of malignant cells within the needle tract and subsequent development of a chest wall mass. A case of chest wall implantation of adenocarcinoma of the lung after thin-needle biopsy is reported. The lesion was successfully treated with radical full-thickness excision of the chest wall and immediate reconstruction with a large rectus abdominis musculocutaneous flap.

Adenocarcinoma↗
PubMed1989

A quality assurance model of operative mortality in coronary artery surgery.

Quality assurance in coronary artery bypass grafting (CABG) surgery requires a comparison of operative mortality against an accepted standard of care. Raw mortality statistics are unacceptable in this context, and risk factor analysis is essential. However, this principle has not been adequately demonstrated in previous reports. Our goal in this study was to develop a risk model of accepted CABG mortality and illustrate its proper use in coronary artery surgery. The model was derived from a Bayesian analysis of 6,630 patients undergoing CABG in the Coronary Artery Surgery Study (CASS) registry. Age, sex, ventricular function, previous myocardial infarction, extent of coronary artery disease, unstable angina, and surgical priority were used by the model to sort patients into risk categories. From January 1984 through December 1987, 840 patients underwent isolated CABG at our hospital. With raw mortality data, the 3.9% (33/840) mortality of our patients was significantly different from the 2.3% (153/6,630) CASS mortality (p less than 0.001). When our patients were entered into the CASS model for risk stratification, however, our CABG mortality conformed to the CASS experience. These results illustrate the fallacy of using raw mortality statistics for interinstitutional comparisons. This type of risk model is a fundamental element of CABG quality assurance.

Aged↗
PubMed1989

Use of artificial intelligence for the preoperative diagnosis of pulmonary lesions.

The relatively new field of artificial intelligence has spawned a variety of techniques associated with computer-assisted diagnosis. These techniques have been applied to the diagnosis of pulmonary lesions, but previous reports have focused on medical rather than surgical populations and the results have been evaluated using only retrospective patient surveys. We used a Bayesian algorithm to develop a diagnostic computer model for prospectively evaluating patients undergoing thoracotomy for suspected pulmonary malignancy. Patients who had a preoperative diagnosis were not included. Preoperative clinical and radiographic parameters for 100 consecutive patients were prospectively entered into the diagnostic model, which then categorized the lesion as benign or malignant. The computer predictions agreed with the final histological diagnosis in 95 of the 100 patients. The sensitivity was 96% and the specificity was 89% for this prospective series. These results indicate that the computer-assisted diagnosis of pulmonary lesions may have a role in this clinical setting.

Adult↗
PubMed1989

Preoperative evaluation and general preparation for chest-wall operations.

Chest-wall reconstruction is a major procedure with a risk of life-threatening complications. Accurate preoperative assessment is therefore critical, as it allows detection and treatment of correctable problems and permits the surgeon to individualize postoperative management. Risk factors may be cardiovascular, pulmonary, or nutritional. The guiding principle of planning for the reconstruction is that there must be absolutely no tension at the site of the full-thickness defect in the chest wall.

Heart Diseases↗
PubMed1989

Reconstruction of congenital chest-wall deformities.

Pectus deformities and Poland's syndrome are two relatively common congenital deformities of the chest wall that are amenable to reconstruction. The extent of the structural deformity in pectus deformity and the degree of associated cardiopulmonary dysfunction are critical variables in preoperative assessment. The operative approaches range from more extensive sternal eversion to the more popular subperichondrial cartilage resection with or without internal fixation. In Poland's syndrome, the options for reconstruction include anterior transfer of the ipsilateral latissimus dorsi muscle through a transaxillary tunnel and attachment to the clavicle and sternum. Submuscular insertion of a mammary prosthesis can be added in the female patient.

Female↗
PubMed1989

Wound healing: relationship of wound closing tension to tensile strength in rats.

A study was conducted to better define the relationship between closing tension and the resulting tensile strength of scars in incisional wounds. Five groups consisting of ten hairless rats were studied. Transverse wounds were created and closed on the back of each rat, with closing tension varied by excising amounts of skin in widths of 0 (control), 15, 30, 45, and 60 mm. The tensile strengths were determined at 28 days. Higher mean tensile strengths were demonstrated in the two groups requiring the highest closing tensions (45 mm and 60 mm of skin excision) with P = 0.0028 and P = 0.00016, respectively. A logarithmic relationship between closing tension and tensile strength was demonstrated using linear regression analysis with t = 6.18, p less than .0001, and R2 = .44.

Animals↗
PubMed1989

Cardiac isoenzyme values after total joint arthroplasty.

The purpose of this study was to prospectively determine what effect total joint arthroplasty had on the myocardial-associated isoenzymes of serum creatine kinase (CK-MB) and lactate dehydrogenase (LD-1:LD-2). Fifty patients treated with total joint arthroplasty of the hip or knee had isoenzyme determinations using automated spectrophotometry and agarose gel electrophoresis. Skeletal muscle injury associated with the trauma of surgery resulted in significant elevations of the absolute value of CK-MB; however, the percentage of CK-MB comprising total CK activity and LD-1:LD-2 did not rise significantly in patients who did not experience postoperative myocardial infarction. It is important to determine both serum CK-MB and LD-1:LD-2 in suspected postoperative myocardial infarction since false positive elevations of CK-MB can occur. Elevations of CK-MB exceeding 50 International Units/liter or 5% of the total CK activity combined with LD-1:LD-2 exceeding 1.0 should not be attributed to skeletal muscle injury alone following total joint arthroplasty of the hip or knee.

Adult↗
PubMed1989

Operative treatment of acute hip fractures: its effect on serum creatine kinase, lactate dehydrogenase and their isoenzymes.

Serum creatine kinase, lactate dehydrogenase, and their isoenzymes were prospectively studied in 16 patients who underwent operative treatment of acute hip fractures. No perioperative myocardial infarctions occurred; however, two patients died of noncardiac causes. We found that skeletal muscle injury associated with operative treatment of acute hip fractures did not result in significant elevations of serum CK-MB or the LD-1/LD-2 ratio. CK-MB activity exceeding 5% of total CK activity was observed in five patients who did not experience acute perioperative myocardial infarction; however, no patient had an absolute CK-MB value exceeding 50 IU/L. Elevations of serum CK-MB exceeding 50 IU/L and a LD-1/LD-2 ratio exceeding 1.0, therefore, should not be attributed to skeletal muscle injury alone following the operative treatment of acute hip fractures.

Acute Disease↗
PubMed1988

Intraosseous infusion of hypertonic glucose and dopamine.

Intraosseous infusion of drugs for resuscitation and of fluids has been advocated as an alternate emergency technique to intravenous infusion. The reliability of intraosseous infusion of many substances has not been established. Glucose and dopamine hydrochloride are two commonly used emergency drugs in pediatric practice that have not been carefully studied when administered into the bone marrow. In an animal model, we compared the response of an intraosseous injection of hypertonic glucose with that of an intravenous injection of hypertonic glucose. Serum glucose measurements following the injection revealed both routes of administration to be effective. A dopamine infusion was then administered through the bone marrow for 20 minutes. A statistically significant rise in blood pressure was observed two minutes after initiation of the infusion. Intraosseous infusion of hypertonic glucose and dopamine is an effective route by which to administer these medications and is potentially useful in emergency situations in which intravascular access is delayed.

Animals↗
PubMed1988

Use of a Bayesian statistical model for risk assessment in coronary artery surgery.

A computerized statistical model based on the theorem of Bayes was developed to predict mortality after coronary artery bypass grafting. From January, 1984, to April, 1987, at our hospital, 700 patients underwent isolated coronary artery bypass grafting. The presence or absence of 20 risk factors was determined for each patient. The first 300 patients formed the initial database of the Bayesian predictive model, and the remaining 400 patients were prospectively evaluated in four groups of 100 each. Each group was prospectively evaluated and then incorporated into the database to update the model. There was good agreement between predicted and observed results. Bayesian theory is particularly suited to this task because it (1) accommodates multiple risk factors, (2) is tailored to one's specific practice, (3) determines individual, rather than group, prognosis, and (4) can be updated with time to compensate for a changing patient population. These flexible attributes are especially valuable in light of recent changes in the coronary artery bypass graft patient profile.

Aged↗
PubMed1988

Poland's anomaly. Natural history and long-term results of chest wall reconstruction in 33 patients.

Poland's anomaly is an uncommon congenital aberration of the chest wall characterized by absence of the pectoralis major muscle and other nearby musculoskeletal components. In this series, a wide spectrum of thoracic deformities was associated with the Poland anomaly, ranging from segmental agenesis of the ribs, sternum, and nearby muscles, to simple aplasia of the pectoralis major muscle. Although little disability was associated with the syndrome, the patients primarily sought operative correction due to the asymmetry and their perception of adverse cosmesis. Over a 10-year period, 53 operations were performed on 27 individuals with the goal of correcting the abnormal contour of the chest wall. The most successful reconstructions involved the use of the latissimus dorsi muscle, which was detached and transferred to the anterior chest wall while preserving the neurovascular pedicle. In women, this was accompanied by insertion of a mammary prosthesis. Reconstruction of the so-called "herniation" of the lung with rib grafts or alloplastic materials was found to be unnecessary, and the use of custom-made chest wall prostheses is not recommended, since four of five of these devices had to be removed due to migration, erosion of local tissues, and adverse cosmesis.

Adolescent↗
PubMed1988

Randomized clinical trial of preoperative and postoperative adjuvant chemotherapy with cisplatin, vindesine, and bleomycin for carcinoma of the esophagus.

Thirty-nine patients with potentially resectable cancer of the middle or lower esophagus who had not previously been treated were randomly assigned to receive either immediate operation (n = 20) or operation plus preoperative and postoperative therapy with cisplatin, vindesine, and bleomycin (n = 19). Patients were stratified by tumor size and location and by sex, with no significant differences appearing between the two treatment groups. Median follow-up for both groups was 30 months. The preoperative response rate to chemotherapy was 47%. The postoperative complication rate for patients in the operation-only group was 47%; it was 29% for patients receiving chemotherapy. The overall resectability rates were similar for the two groups. Patients responding to chemotherapy preoperatively had significantly prolonged survival (median greater than 20 months) when compared with either nonresponders (median 6.2 months) or patients receiving only operation (median 8.6 months). A highly significant correlation was noted between a weight loss of less than 10% and response to chemotherapy, which suggested that responses occurred in patients with less advanced disease. We conclude that preoperative and postoperative cisplatin, vindesine, and bleomycin chemotherapy has acceptable toxicity and does not increase the incidence of postoperative complications. The natural history of epidermoid carcinoma of the esophagus is altered and overall survival is prolonged for patients responding to preoperative chemotherapy. Potential responding patients can be identified by the degree of preoperative weight loss.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Sternal blood flow after median sternotomy and mobilization of the internal mammary arteries.

Although the internal mammary artery (IMA) is superior to the saphenous vein graft for bypassing certain coronary arterial obstructive lesions, such operations may predispose the patient to sternal infection or dehiscence--presumably as a result of sternal ischemia. This study was designed to measure sternal blood flow before and after median sternotomy and IMA mobilization in order to quantify the hemodynamic effects of these procedures. Rhesus primates were randomized into control, unilateral IMA-harvested, and bilateral IMA-harvested groups. After selective angiography enabled confirmation of IMA patency, 15 micron microscopheres, labeled with specific-spectra radioactive isotopes, were injected at baseline, after sternotomy, and after IMA harvesting. The sternal halves were subjected to gamma counting, and sternal circulation was accurately quantified. Our results showed that blood flow to the sternal halves in which the IMA was harvested decreased precipitously (from 4.5 to 0.8 ml/gm/min; p less than or equal to 0.001), although it remained unchanged in response to median sternotomy. This represented a 90% decrease in the mean rate of flow within the IMA-harvested sterna versus a stable flow rate for the unharvested sides. We conclude that mobilization of the internal mammary artery, as in coronary bypass procedures, significantly devascularizes the sternal half from which it was harvested.

Animals↗
PubMed1988

Efficacy of a hyperinflation and hyperoxygenation suctioning intervention.

Limited data are available on the efficacy of a common endotracheal suctioning intervention to prevent decreases in arterial oxygenation (PaO2) after endotracheal suctioning. We evaluated the effect of five hyperinflation breaths with hyperoxygenation, administered before and after endotracheal tube suctioning, in anesthetized, paralyzed sheep with normal lung function and with abnormal lung function induced by pulmonary acid aspiration. Using a second ventilator to deliver hyperinflation and hyperoxygenation prevented PaO2 from falling below control values after endotracheal tube suctioning in animals with either normal or abnormal lung function. The PaO2 rise after hyperinflation and hyperoxygenation in animals with abnormal lung function, however, was less than that observed in animals with normal lung function. Using manual resuscitation bags to deliver the hyperinflation breaths with hyperoxygenation prevented PaO2 from falling below control values after endotracheal suctioning in animals with normal lung function. When lung function was abnormal, however, there were significant PaO2 decreases when manual resuscitation bags were used to deliver the intervention. These results highlight the difference in PaO2 response when hyperinflation and hyperoxygenation suctioning interventions are delivered with mechanical versus manual techniques. These results also emphasize that the response to hyperinflation and hyperoxygenation differs in subjects with normal versus abnormal lung function. Laboratory evaluation of endotracheal tube suctioning interventions should use abnormal lung function models, rather than normal lung function models, to approximate more closely the critically ill patient population that requires suctioning.

Animals↗