Effect of hypoxic hypoxia on systemic vasculature

Effects of hypoxic hypoxia (HH) on cardiac output (CO), CO distribution, arterial and venous pressure-flow curves, vascular compliance, vascular time constant (tau), and resistance to venous return (RVR) were evaluated on six dogs. The vascular bed was isolated into four compartments depending on venous drainage: superior vena cava (SVC), splanchnic, renal and adrenal, and the remainder of the inferior vena cava (IVC). Low arterial O2 content and PO2 produced a threefold increase in CO at the same mean arterial pressure and a significant redistribution of CO to the SVC. Arterial pressure-flow curves decreased their slope (i.e., flow resistance) by a factor of two in the IVC and renal beds and by a factor of three in the splanchnic and SVC beds. Venous pressure-flow curves for the animal also decreased their slope significantly. HH causes a twofold increase in venous compliance and in mean venous pressure; tau did not change, but RVR halved. Seventy percent of the CO increase is explained by the increase in mean venous pressure and 30% by the reduction in RVR.

Low electrocardiographic voltage in pericardial effusion

Although low ECG voltage has been associated with pericardial effusion, its diagnostic usefulness in such patients is unclear. When we examined the relationship between the volume of pericardial effusion and low voltage in 28 patients who underwent pericardial drainage, 14 patients exhibited low voltage (sum of limb lead QRS amplitudes of 30 mm or less). In eight patients, the QRS amplitude was 5 mm or less in each of the standard leads (absolute low voltage). There was no significant correlation between the volume of the effusion and the QRS amplitude (r = -0.30). This correlation did not improve (r = -0.37) when patients with left ventricular hypertrophy were excluded. Following pericardial drainage, the QRS amplitude increased in 21 of 24 patients and decreased in three. Low voltage persisted in nine patients; the pericardium was thickened in seven of the nine. Analysis of the sensitivity and specificity revealed acceptable sensitivity only with large effusions and no left ventricular hypertrophy. Absolute low voltage appeared to be specific in the diagnosis of moderate and large effusions among patients with pericardial effusion selected for this study.

Severe rectal injury following radiation for prostatic cancer

Between 1970 and 1981, 348 patients underwent definitive irradiation. Of these patients 6 (1.7 per cent) sustained severe rectal injury as manifest by major rectal bleeding, rectal stricture, rectal mucosal slough and rectal ulceration. Severe rectal injury was observed in 0 of 13 patients (0 per cent) treated with 125iodine, 3 of 329 (1 per cent) treated with 6,400 to 6,800 rad external irradiation, 2 of 39 (5 per cent) treated with 7,000 to 7,300 rad external irradiation, and 1 of 7 (14 per cent) treated with 198gold and external irradiation. The impact of radiation dose, radiation therapy technique and surgical trauma was assessed. Rectal injury was managed by supportive measures in 2 patients and by diverting colostomy in 3 with benefit. One patient underwent abdominoperineal resection. A small bowel fistula and an intra-abdominal abscess developed, and the patient died.

Preventive content of adult primary care: do generalists and subspecialists differ?

We compared preventive care performed by 20 generalists and 20 subspecialists practicing in Santa Clara and San Mateo Counties, California, by auditing charts of adult primary care patients for compliance with recommendations of the Canadian Task Force on the Periodic Health Examination. Generalists and subspecialists both provided 49 per cent of recommended preventive services. The two groups did not differ significantly in performance of any individual service. Performance varied widely within both groups. Of many factors explored, only two were associated with more preventive services: provision of a complete physical examination to the patient, and a physician's belief in the importance of a given service. The "generalist vs. subspecialist" debate assumes that a physician's specialty classification is an important predictor of behavior. For the performance of preventive care, this was not true in our study. Instead, physicians' beliefs and practice habits may be major determinants of the quality of preventive care provided. These exploratory findings needed confirmation in other settings.

Cerebral hemodynamics in the diagnosis of normal pressure hydrocephalus

We studied the effect of CSF drainage on cerebral blood flow (CBF) in normal pressure hydrocephalus (NPH) and non-NPH dementia using the 133Xenon inhalation technique. Dementia patients had lower CBF than matched elderly normals. Flow values for NPH and non-NPH patients did not differ before or after CSF drainage. CBF did not increase after lumbar puncture, and these measurements were not useful in predicting the outcome of ventricular shunt surgery. Postoperative CBF did not increase after successful shunting.

Duration of ejection in aortic stenosis: effect of stroke volume and pressure gradient

The theoretical effect of variable ventricular function on left ventricular ejection time in aortic stenosis was predicted by applying data measured in 52 patients with pure aortic stenosis to equations derived from the relations of Gorlin and Gorlin and Weissler et al. Ejection time and aortic valve area are not, of necessity, linearly related because (Formula: see text) where LVET is left ventricular ejection time, k is a constant, SV is stroke volume, PG is mean aortic pressure gradient and AVA is aortic valve area. When the patients were separated into performance groups on the basis of cardiac index (at 2.8 liters/min per m2), the linear regression relating the measured SV/square root PG with valve area in 18 patients with normal function (SV/square root PG = 11.1 AVA + 2.0, r = 0.969, p less than 0.001) predicted ejection time prolongation with decreasing valve area. In 34 patients with poor function, however, the decrease in SV/square root PG with decreasing valve area was more marked (SV/square root PG = 12.6 AVA + 0.4, r = 0.894, p less than 0.001), predicting a shorter ejection time at any given valve area in this group. As predicted by the effect of valve area on the equation, ejection time becomes most variable at a small aortic valve area. Independent ejection time measurement in these patients validated the predicted effect.

Role of the PA in a prepaid medical care group

The Department of Physician Assistants at the LaGuardia Medical Group (Queens, New York) includes, besides Pas, nurse practitioners, certified nurse midwives, and nurse clinicians. The program of hiring these professionals began with the idea that the PA could, though in a limited way, be helpful to the physician in such a large group. It was soon recognized that not only were PAs functioning effectively in this capacity, but that the professional skills of the PA could be used for more advanced functions than were originally envisioned. The author stresses the importance of a strong organizational basis, effective self-rule, and rigid and persistent supervision of activities.

Nuclear magnetic resonance imaging of vasculature of abdominal viscera: normal and pathologic features

Nuclear magnetic resonance (NMR) imaging of intraabdominal vascular anatomy and the effect of various lesions on retroperitoneal and splanchnic vessels was assessed in 67 patients and volunteers using a superconducting magnet (0.35 tesla) and the spin-echo imaging techniques. Because of the low signal generated by flowing blood in most images, blood vessels, including intraparenchymal vessels, were well demonstrated. Clear delineation of the splenic vein facilitated visualization of the normal pancreas and pancreatic masses. Variation in the size and shape of the inferior vena cava and portal venous system reflected constricting and mass lesions. Preliminary observations from this initial experience suggest conspicuity of splanchnic vessels out of proportion to the current spatial resolution of NMR imaging due to the marked natural contrast between flowing blood and solid organs.

Iatrogenic postoperative left ventricular outflow tract obstruction

A 56-year-old female, who underwent aortocoronary bypass graft for occlusion of anterior descending artery is reported, who postoperatively developed a harsh systolic murmur, mitral regurgitation, and intraventricular systolic pressure gradient suggestive of hypertrophic subaortic stenosis. The above findings were due to the administration of dobutamine hydrochloride for hypotension in association with afterload reduction (intra-aortic balloon pumping) and disappeared almost immediately after left ventriculography (volume load).

Echocardiographic quantitation of pericardial effusion

This study was undertaken to test the validity of M-mode echocardiographic quantitation of pericardial effusion. M-mode estimate of the volume of pericardial effusion in 27 patients was compared with the actual volume of pericardial effusion removed during surgical pericardial drainage. The 16 two-dimensional echocardiographic studies in patients with small, moderate, and large pericardial effusions were reviewed to examine the distribution of pericardial fluid around the heart. Although there was good correlation between the echocardiographic estimate and the actual volume removed during surgery (r = 0.78), significant overestimation and underestimation were noted. Our findings suggest that the errors in the estimate could be attributed in part to difficulties in precise measurement of the epicardial and pericardial landmarks and in part to nonuniform distribution of pericardial fluid around the heart.

Rapid visualization of the right coronary artery with an anterior-inferior ostium

We describe an approach for rapid visualization of the right coronary artery (RCA) with an anterior-inferior ostium. The success rate of this method has been 100% without any complications. It decreases patient discomfort, reduces radiation exposure, and increases safety by decreasing procedure time.

Diagnosis of severe tricuspid regurgitation

Fifty-nine patients were studied who had severe tricuspid regurgitation which was confirmed by right ventriculography and during surgery in order to determine the incidence of clinical, radiologic, and hemodynamic clues of severe tricuspid regurgitation. Eighty-eight percent of patients had Carvallo sign alone or in combination with pulsatile liver or prominent jugular venous V waves, and the classic triad was present in 42 percent. Most patients had enlargement of the right atrium on chest x-ray film. The classical "ventricularization" pattern of right atrial pressure was seen in 30 percent, prominent V waves with rapid Y descents were present in 37 percent, and normal contour of right atrial waves with normal mean pressure was seen in 33 percent. The inspiratory maneuver was helpful to induce the ventricularization pattern or prominent V waves with rapid Y descents especially in patients with normal right atrial pressure waves. In conclusion, right ventriculography is a sensitive and accurate method for detecting and quantitating tricuspid regurgitation in the absence of the diagnostic physical findings.

[Treatment of cerebral fungus by ventriculoatrial shunt. Report of 5 cases]

The causes and pathology of the cerebral fungi are analyzed. Five patients with this lesion were submitted to ventriculoatrial shunt. All were cured. According to the authors this is the best treatment for cerebral fungus, at present.

Localization of parathyroid adenoma by computed tomography

Sixteen consecutive patients with the clinical diagnosis of hyperparathyroidism, nine with and seven without previous surgery, had computed tomography (CT) examinations preoperatively to evaluate the use of CT in localizing parathyroid adenomas. The patients were scanned at 5 mm intervals from the level of the hyoid bone to the lung apex. Scanning of the mediastinum was performed at 10 mm intervals from apex to lung base. Computed tomography correctly identified prospectively the site of the adenoma in 10 of 13 patients (77%), with surgically proven adenomas. In retrospect, all 13 adenomas could be identified. One false positive diagnosis of adenoma was made. Our study suggests that CT may be beneficial in the preoperative localization of parathyroid tumors, particularly in ectopic locations.

Response of lymph node metastasis to sequential estrogen and radiation therapy in prostate carcinoma

Increasingly sophisticated diagnostic studies have shown a high incidence of tumor spread to the regional lymph nodes. The status of the lymph nodes has been evaluated by noninvasive diagnostic procedures such as lymphangiography and computerized axial tomography. The applicability of these procedures has been enhanced by the use of stringent criteria. Gross lymph node metastasis can be diagnosed with considerable confidence. Serial observations of lymphangiograms and computerized axial tomograms before and two months after the administration of estrogens provide an added dimension to the interpretation of lymph node metastasis. The nature and range of the response of lymph node metastasis were observed. Survival of patients with gross lymph node metastasis treated by sequential estrogen and radiation therapy was evaluated. A total of 11/18 (61 per cent) of patients remained free of symptoms, 8/11 (74 per cent) with a favorable lymph node metastasis responsive to estrogen therapy, and 3/7 (42 per cent) with lymph node metastasis refractory to estrogen therapy. Follow-up computerized axial tomograms of the lymph nodes done at one and two years after irradiation showed a persistent favorable response. Five patients are alive with disease, and 2 patients died of the disease.

Cystic complex composite odontoma. Report of two cases

The two cases presented here involved complex composite odontomas that had become cystic. They were very different in appearance; the first case being almost classic and the second case showing more bizarre configuration and being associated with a much larger cystic cavity. Two different surgical approaches were used. In the first case a bone graft from the iliac crest was used to fill the extensive mandibular defect. In the second case, enucleation with good primary closure was thought to be sufficient since good bony margins were evident and the likelihood of pathologic fracture was considered minimal.

Cardiac specific antigen and antibody in immunopathogenesis of cardiac disease

Antibody to human cardiac extracts was detected in the sera of many patients undergoing open heart surgery. A passive hemagglutination assay using cardiac extracts as antigen coated onto erythrocytes showed the development of cardiac antibody in the patients, with peak titers usually one to three weeks after the surgery. Radioimmunoassay revealed the presence of cardiac specific myoglobin antigen antigen in the sera of many patients, with peak levels 1-3 days after the procedure. A correlation was observed between development of circulating serum antibody and appearance of cardiac myoglobin antigen. These results support the view that immunologic disease related to release of cardiac antigen in patients undergoing heart surgery may be a factor in post-cardiotomy disease.

The combined use of computed tomography and endoscopic retrograde cholangiopancreatography in the assessment of suspected pancreatic neoplasm: a blind clinical evaluation

Sixty-one consecutive patients suspected of having pancreatic neoplasms had endoscopic retrograde cholangiopancreatography (ERCP) and computed tomography (CT). The ERCP results were 62% accurate, 8% false negative, and 3% failure. The overall accuracy in cases of successful pancreatic duct cannulation was 88%. The results of CT were 76% correct, 5% false positive, 13% false negative, and 6% indeterminate. Excluding ERCP failure, the CT-ERCP diagnosis was identical in 67%. When findings were identical, the accuracy rate was 93%, high than that of either study alone. The ERCP-CT examinations were often complementary and generally led to a more accurate and specific diagnosis.