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Biomedical subjects

W R Thompson

Publications and source records attributed to W R Thompson.

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

Hormonal responses to graded surgical stress.

We tested the hypothesis that selected hormonal responses to surgery reflect the degree of surgical stress. Plasma norepinephrine, epinephrine, thromboxane B2, cortisol, serum angiotensin converting enzyme, thyroxine, triiodothyronine, free thyroxine, and free triiodothyronine levels were measured preoperatively, and then one hour, 24 hours, and five days postoperatively in three groups of patients. The groups were as follows: group 1, "minimal" stress, eg, inguinal hernia repair (n = 10); group 2, "moderate" stress, eg, cholecystectomy (n = 12); and group 3, "severe" stress, eg, subtotal colectomy (n = 9). Patients in group 1 showed no significant surgery-induced changes in hormonal values. The stress-induced changes in patients in groups 2 and 3 were seen at one and occasionally 24 hours; however, by five days postoperatively, circulating hormone values had returned to preoperative levels. Increases in plasma cortisol, norepinephrine, and epinephrine, and decreases in serum angiotensin converting enzyme levels characterized the surgery-induced hormonal changes. Conclusions are as follows: hormonal responses do reflect the degree of surgical stress; the hormonal changes are transient, lasting no longer than 24 hours in patients after uncomplicated surgery; hormonal responses to minimal surgical stress are negligible.

Adult↗
PubMed1987

Comparison of ventricular volumes in normal and post-myocardial infarction subjects.

In an effort to determine left ventricular volume changes between upright rest and exercise, 15 male late post-infarction patients (group A) and 13 normal matched volunteers (group B) were studied. Patients were at least 12 months post-cardiac event. Upright two-dimensional echocardiographic recordings were performed by the same cardiac sonographer using the apical four-chamber view at rest and immediately post-exercise after the subject reached 85% of measured maximal heart rate. Single-plane planimetry of the cross-sectional area was used for calculation of left ventricular volumes. Two subjects in each group failed to demonstrate adequate (i.e., measurable) echocardiograms and were excluded from the statistical analyses. Two-way analysis of variance for repeated measures was followed by the Newman-Kuels multiple comparison procedure to determine statistically significant differences between means (P less than 0.05). The results indicated no differences in any of the measured parameters at rest between the groups. Exercise values demonstrated a significant increase in end-diastolic volume, stroke volume, and ejection fraction with exercise only in group B. End-systolic volume did not change in either group. Cardiac output and heart rate increased in both groups. These data suggest that in the upright position, cardiac output increases in normal males due to an increase in heart rate and stroke volume (increases in end-diastolic volume) and by increases in heart rate alone in the post-infarction group.

Adult↗
PubMed1986

Pharmacokinetics of ranitidine in critically ill patients.

The plasma pharmacokinetics of ranitidine (50 mg i.v.) have been studied in 17 critically ill patients in an intensive care unit. Measurements of gastric aspirate pH were also made in 16 of these patients. Ranitidine therapy was part of the patients' normal drug regimen. Ranitidine plasma concentration was measured by high performance liquid chromatography and appropriate polyexponential equations were fitted to concentration-time data to enable calculation of relevant pharmacokinetic parameters. Values of the volume of the initial dilution space (median = 89 ml kg-1) and volume of distribution at steady state (median = 1.54 l kg-1) were about 60% of corresponding mean literature values for healthy controls. Plasma clearance (median = 4.22 ml min-1 kg-1) and terminal half-life (median = 4.7 h) were about 2-3 fold less and 2-3 fold greater, respectively, than values for healthy controls. There was wide interpatient variation in all the pharmacokinetic parameters. Renal impairment was considered to be largely responsible for the low plasma clearance. Gastric aspirate pH was measured at 0, 1 and 7 h after ranitidine administration and 58% of samples were found to be above pH 4. Four patients had gastric pH values which were consistently below pH 4 despite average trough plasma ranitidine concentrations equal to or greater than those required for a 50% suppression of gastric acid secretion in normal volunteers.

Adult↗
PubMed1986

Extended sphincteroplasty for juxtapapillary duodenal diverticulum.

The application of the sphincteroplasty in the treatment of juxtapapillary diverticulum is presented. The relative simplicity of the procedure compared with excision or diversions, or both, may allow more aggressive treatment of such diverticula in borderline situations. In addition, this approach raises the possibility that the sphincteroplasty might be accomplished endoscopically in situations in which the gallbladder has been removed and biliary tract symptoms persist.

Ampulla of Vater↗
PubMed1985

Percutaneous subclavian catheterization for prolonged systemic chemotherapy.

Recent experience with 108 Broviac catheters was reviewed. Sixty-eight were percutaneously placed in the subclavian veins of adults receiving systemic chemotherapy. For subclavian catheters perioperative and late complications were unusual. There was no pneumothorax or serious bleeding associated with insertion, even in severely thrombocytopenic patients. Mean catheter life was 93 days. Infection occurred in only five cases (7%). We conclude that percutaneous placement of right atrial catheters is a safe procedure which provides reliable access for prolonged chemotherapy in cancer patients.

Adolescent↗
PubMed1985

Gallbladder disease in the morbidly obese.

During a 7 year period, 200 consecutive morbidly obese patients underwent a standardized gastric exclusion procedure. Group A was composed of the first 120 patients and Group B of the last 80 patients. In Group A, 22 patients had undergone a previous cholecystectomy and 12 patients had a cholecystectomy at the time of gastric exclusion because of positive diagnostic studies or palpation of stones. Of the remaining 87 patients in this initial group who were at risk for the development of gallbladder disease, 24 (27.6 percent) required a cholecystectomy in the first 3 postoperative years (mean 15.6 months). Twelve patients had acute cholecystitis, 3 patients had choledocholithiasis, and 1 patient had acute gallstone pancreatitis. In Group B, 18 patients had a previous cholecystectomy, 15 had positive diagnostic studies (ultrasonography and oral cholecystography) preoperatively, and 47 had negative studies. Cholecystectomy was routinely performed at the time of gastric exclusion surgery in the 62 patients with gallbladders in Group B. Of the 47 patients who had normal preoperative diagnostic studies, 40 (85.1 percent) had abnormal histologic findings in the gallbladder. Only seven patients in Group B had a normal gallbladder (14.7 percent). We conclude that gallbladder disease is considerably more frequent in the morbidly obese population (91.3 percent) than has previously been recognized, that diagnostic studies are frequently inaccurate, and that postoperative gallbladder disease is common (28.7 percent). On the basis of these results, routine cholecystectomy at the time of gastric exclusion surgery is recommended.

Adolescent↗
PubMed1985

Prospective hematologic evaluation of gastric exclusion surgery for morbid obesity.

To evaluate the long-term frequency and severity of anemia and selected vitamin and mineral deficiencies after gastric exclusion surgery for morbid obesity, the authors prospectively examined hematologic and nutritional parameters in 150 consecutive patients. These patients underwent a standardized gastric exclusion procedure during a six-year period (1976-1982) and were closely followed for up to seven years (mean, 33.2 months). Anemia developed in 36.8% of the population at a mean time from operation of 20 months. It was more frequent in women than in men (p less than 0.01), and it required transfusions in 3.5% of the population. A low serum iron concentration developed in 48.6%, iron deficiency in 47.2%, a low serum vitamin B12 concentration in 70.1%, vitamin B12 deficiency in 39.6%, and RBC folate deficiency in 18% of the population. Both iron and folate deficiencies responded to oral replacement. As a result of the high frequency and severity of anemia and nutritional deficiencies noted, all gastric exclusion patients should, as a minimum, be placed on oral multivitamin preparations containing iron, folate and vitamin B12. In addition, it is imperative that these patients be followed closely for the remainder of their lives with appropriate studies and replacement as necessary.

Adolescent↗
PubMed1985

A comparison of continuous flush devices.

Six different makes of continuous flush device were compared for reliability of flow rate and ease of use. All of the devices tested were considered suitable for flushing of vascular pressure monitoring catheters. However, flow rates were considered too variable for control of drug infusions or flushing of intracranial pressure monitoring systems.

Blood Pressure Determination↗
PubMed1984

Intraluminal erosion and migration of the Angelchik antireflux prosthesis.

Despite a paucity of published clinical trials, use of the Angelchik antireflux prosthesis has increased dramatically since its introduction in 1979. Serious complications of this device have begun to appear. We dealt with two cases of erosion of the prosthesis into the gastrointestinal tract, one of which represents, to our knowledge, the first reported case of a gastroenteric fistula secondary to the device. Other complications of the use of this prosthesis have appeared in the literature. Carefully controlled clinical studies with long-term follow-up are needed to assess the overall benefits and safety of this new antireflux prosthesis.

Equipment Failure↗
PubMed1984

Prospective metabolic evaluation of 150 consecutive patients who underwent gastric exclusion.

The effect of weight loss produced by gastric exclusion on the metabolism of previously morbidly obese persons was examined. A standardized gastric exclusion procedure was performed in 150 morbidly obese patients during a 6 year period. These patients were followed for from 6 to 60 months (mean 27.8 months). The mean excess weight loss was 75 percent and was maintained from 2 to 5 years. A small but significant decrease was noted during the first 3 to 6 postoperative months in the parameters of protein metabolism examined. Although this may reflect mild depletion in protein stores, of greater importance was the demonstration that these parameters spontaneously corrected themselves by 12 months. Mild abnormalities in serum electrolyte concentrations were noted in the postoperative period. They appeared to be related to dehydration, were not clinically significant, and also resolved spontaneously. Clinically significant abnormalities in divalent ions were absent. Significant and sustained reductions in blood pressure, fasting glucose concentration, serum triglyceride values, and uric acid and hepatic enzyme concentrations were demonstrated in the entire population. A small and non-sustained decrease in cholesterol was seen. Hypertension was eliminated in 96 percent of the affected subpopulation, diabetes in 100 percent, gout in 100 percent, hyperlipidemia in 92 percent, and improved hepatic function was found in 95 percent. These changes should reduce the overall morbidity and mortality of the patient population in the future.

Adolescent↗
PubMed1984

The organic aerosols of Titan.

A dark reddish organic solid, called tholin, is synthesized from simulated Titanian atmospheres by irradiation with high energy electrons in a plasma discharge. The visible reflection spectrum of this tholin is found to be similar to that of high altitude aerosols responsible for the albedo and reddish color of Titan. The real (n) and imaginary (k) parts of the complex refractive index of thin films of Titan tholin prepared by continuous D.C. discharge through a 0.9 N2/0.1 CH4 gas mixture at 0.2 mb is determined from x-ray to microwave frequencies. Values of n (approximately equal to 1.65) and k (approximately equal to 0.004 to 0.08) in the visible are consistent with deductions made by ground-based and spaceborne observations of Titan. Many infrared absorption features are present in k (lambda), including the 4.6 micrometers nitrile band. Molecular analysis of the volatile component of this tholin was performed by sequential and non-sequential pyrolytic gas chromatography/mass spectrometry. More than one hundred organic compounds are released; tentative identifications include saturated and unsaturated aliphatic hydrocarbons, substituted polycyclic aromatics, nitriles, amines, pyrroles, pyrazines, pyridines, pyrimidines, and the purine, adenine. In addition, acid hydrolysis produces a racemic mixture of biological and non-biological amino acids. Many of these molecules are implicated in the origin of life on Earth, suggesting Titan as a contemporary laboratory environment for prebiological organic chemistry on a planetary scale.

Aerosols↗
PubMed1984

Effect of long-term continuous infusion of alfathesin on clinical biochemical and haematological parameters.

Clinical biochemical and haematological parameters during long-term continuous infusion of alfathesin were studied in twelve neurosurgical patients who did not have multiple organ failure. Significant changes which were possibly caused by alfathesin were an alteration of blood film morphology, an elevation of plasma triglyceride and a reduction in plasma high-density lipids.

Adult↗
PubMed1984

Pressure infusors: variability in delivered infusion pressure.

A pressure infusor was used to apply external pressures of 300, 250, 200, and 150 mm Hg to 500-ml plastic bags of saline. At constant applied pressure, 50-ml aliquots of saline were periodically withdrawn. The delivered pressures were less than the applied pressures, and the difference increased as the volume of saline within the bag decreased. This inherent pressure difference should be considered when the system is used with a continuous flush device.

Catheterization↗
PubMed1983

Complications and weight loss in 150 consecutive gastric exclusion patients. Critical review.

Results of extensive follow-up for weight loss and complications in 150 consecutive patients who underwent a standardized gastric exclusion procedure have been presented. A comparative review of the literature has also been presented. All patients were followed for up to 6 years (mean 27.8 months). Only one patient was lost to follow-up. Complications during this period occurred in 54.7 percent of our patients. These were mainly postsurgical biliary disease and ventral hernias. Our recent experience has suggested that the latter complications could have been prevented. The absence of pulmonary embolism, pneumonia, and stomal ulcer in our series, as well as the low incidence of perforations, thrombophlebitis, and stomal and pouch complications suggest that the occurrence of these complications can be minimized as well. Patients in this series lost an average of 75 percent of their excess weight, 38 percent of their original weight, and stabilized at 30 percent above their ideal body weight. Ninety percent of the weight loss occurred in the first 12 months. Eighty percent of the patients, however, continued to lose weight 18 months postoperatively and 40 percent lost weight up to 24 months postoperatively. Weight loss has been maintained from 2 to 5 years. In conclusion, analysis of available data has demonstrated that careful patient selection, attention to technical detail, and close follow-up are of paramount importance for providing successful results and minimizing complications in the morbidly obese population who undergo gastric exclusion surgery.

Adolescent↗
PubMed1983

Influence of body composition on energy requirements of beef cows during winter.

Twenty Angus-Hereford and 20 Angus-Holstein cows were individually fed 12.9 or 18.0 Mcal metabolizable energy (ME)/head daily from November 28, 1979 through February 21, 1980. Energy retentions for the winter feeding period were calculated by determining body composition at the initiation and at the termination of the feeding period. After the experimental period, all cows were managed the same through weaning. Maintenance energy requirements (Kcal/d) estimated from linear regressions of energy retentions on ME intakes per unit body weight (BW).75 were 127.6 and 140.3 kcal/BW.75 for Angus-Hereford and Angus-Holstein cows, respectively. Estimates of maintenance energy requirements for thin and fat cows within each breed type indicated that fatter cows of Angus-Hereford breeding had 6.1% lower energy requirements than thinner cows. Opposite trends occurred with Angus-Holstein cows, where fat cows had 2.7% higher maintenance requirements. Estimated maintenance energy requirements were higher (P less than .01) for protein than fat tissue. Maintenance energy requirements of fat was -1.55 kcal ME/kg for Angus-Hereford cows, indicating that for cows of the same lean body mass, cows with more fat have a lower daily energy requirement during winter. Angus-Holstein cows had an estimated maintenance energy requirement of fat of 51.11 kcal ME/kg. Because cattle of Holstein breeding have less subcutaneous fat than cattle of the beef breeds, and less subcutaneous fat would provide less insulation, the estimated maintenance requirements of fat in Angus-Holstein cows may be an estimate of the true maintenance requirement of fat. Estimates of the partial efficiency of ME use for tissue gain and the ME sparing effect of body tissue loss were 78.8% and .70, respectively, for Angus-Hereford cows and 53.8% and .46, respectively, for Angus-Holstein cows. Regression of retained energy on cow BW.75, body fat and body protein calculated for Angus-Hereford and Angus-Holstein cows from within energy level indicated that BW.75 accounted for less variation in retained energy than weight of empty body fat or protein. Multiple regressions that contained all three variables accounted for 75% and 32% of the variation for Angus-Hereford and Angus-Holstein cows, respectively. Subsequent performance of the cow and calf was not affected by winter energy levels fed, body composition of cows before calving or body energy changes of cows during the winter.

Adipose Tissue↗
PubMed1982

Esophageal perforations: a 15 year experience.

A review of 44 patients with 50 esophageal perforations from 1966 through 1980 is presented. The age span was 15 months to 94 years and the male to female ratio was 1 to 1. Each case was studied with regard to presentation, etiology, treatment and complications. Twenty-two cases of esophageal perforation followed instrumentation, including 6 secondary to Mosher bag dilatation for achalasia. Of the remainder, seven patients had spontaneous perforation, five had external trauma, five had intraoperative injury, two had caustic ingestion, and one each had foreign body ingestion, Zollinger-Ellison syndrome and an incarcerated paraesophageal hiatal hernia. Management was nonoperative in 12 patients, primary repair and drainage was performed in 23 patients, and 9 patients underwent drainage and diversion. This series plus 824 patients with esophageal perforation accumulated from a review of the literature emphasizes the importance of the influence of different methods of treatment and time lapse between occurrence and therapy. The type of perforation had no significance on this series. As a result of the experience gained from this series, a treatment protocol is proposed for the management of esophageal perforation.

Adolescent↗