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Biomedical subjects

R W Vaughan

Publications and source records attributed to R W Vaughan.

At least 91 records · Page 5Linked to original sources
PubMed1984

Genetic markers in narcolepsy.

Narcolepsy has long been known to have a hereditary familial basis. All of 37 patients with narcolepsy expressed the major histocompatibility complex antigen HLA DR2 compared with 21.5% of 200 normal controls. This finding confirms the genetic basis for the disease, and furthermore links it with the short arm of chromosome 6. If the sleep disturbance in narcolepsy is due to a gene-determined defect in a neurotransmitter or receptor factor, the responsible agent may be DR2 itself or an enzyme determinant linked to DR2. This is the strongest HLA-disease association so far discovered.

Adolescent↗
PubMed1984

Cardiovascular effects of nondepolarizing relaxants employed for pretreatment prior to succinylcholine.

A pregnant woman with severe pre-eclampsia experienced a hypertensive crisis following a pretreatment dose (20 mg) of gallamine. That episode initiated a study to determine the cardiovascular effects of non-depolarizing muscle relaxants in 58 nonobese, ASA physical status I and II adults. Subjects were assigned randomly to one of five treatment groups as follows: gallamine (0.29 mg X kg-1), d-tubocurarine (0.04 mg X kg-1), metocurine (0.014 mg X kg-1), pancuronium (0.007 mg X kg-1), or normal saline (control). Baseline measurements of systolic, diastolic, mean arterial pressure, heart rate (HR) and rate pressure product (calculated RPP) were recorded at one-minute intervals while electrocardiogram, lead II, was recorded continuously. Statistically significant increases occurred in HR at minutes 2, 3 and 4; RPP at minutes 3 and 4; and per cent change in HR at minutes 2, 3 and 4 following gallamine pretreatment. The rise in RPP was predominantly due to the elevation in HR. These results suggest that even modest doses of gallamine should be avoided in clinical situations where lability of cardiovascular dynamics can be anticipated.

Adult↗
PubMed1984

Immunoglobulin (Gm) allotype frequencies in idiopathic membranous nephropathy and minimal change nephropathy.

40 Caucasoid patients with idiopathic membranous nephropathy (IMN) and 49 Caucasoid patients with minimal change nephropathy (MCN) were immunoglobulin allotyped for the Gm markers G1m (1, 2, 3) and G3m (5, 11, 21). Compared with normal controls the IMN group had a significantly decreased incidence of the G1m (3); G3m (5, 11) phenotype (P = less than 0.005). This decrease was accompanied by concommitant increase in both the G1m (1, 3); G3m (5, 11, 21) and the G1m (1, 2, 3); G3m (5, 11, 21) phenotypes. The result was most pronounced in IMN patients with deteriorating renal function. In contrast no significant differences were observed between the Gm phenotype frequencies of the MCN patients and controls.

Adolescent↗
PubMed1984

Immunoglobulin allotypes in psoriasis, psoriatic arthropathy and ankylosing spondylitis.

Immunoglobulin allotyping carried out on patients with ankylosing spondylitis, psoriatic arthritis and psoriasis alone showed increase in the phenotype G1m(1,2,3);G3m(5,11,21) in the psoriasis patients in general (p less than 0.05). In patients with psoriasis alone this increase was of greater significance (p less than 0.01). No significant deviation from the normal controls was found in ankylosing spondylitis.

Arthritis, Psoriatic↗
PubMed1983

Immunoglobulin (Gm) allotype frequencies in patients with giant bell arteritis and polymyalgia rheumatica.

Fifty-five Caucasoid patients with polymyalgia rheumatica (PMR) or giant cell arteritis (GCA) were immunoglobulin (Gm) allotyped for this study. Forty-four of these patients had been previously HLA-A,B,C and DR locus allotyped. The incidence of the immunoglobulin allotypic marker Glm(2) was significantly increased in the GCA group (50.00% v. controls 18.75%, P equal less than 0.01). There was a similar but insignificant rise of this Gm marker in the PMR group (27.24% v. 18.75%, NS). The increase in Glm(2) in the GCA group was not accompanied by a corresponding rise in the number of people homozygous for Glm(2), i.e., all the increase could be attributed to patients with the Glm(1,2,3,):G3m(5,10,21)phenotype.

Giant Cell Arteritis↗
PubMed1983

Precision and accuracy of intraoperative temperature monitoring.

Using tympanic membrane (TM) temperature as a standard for core temperature, we quantitated the accuracy and precision of seven other temperature monitoring sites during anesthesia, namely, the nasopharynx, esophagus, rectum, bladder, axilla, forehead, and great toe. Accuracy was quantitated as the difference between TM temperature and the temperature at each of the other sites; precision was quantitated as the correlation between TM temperature and the temperature at each of the other sites. Results indicate that the accuracy of measurements made using the great toe, forehead, and axilla is less than the accuracy of measurements made using the nasopharynx, esophagus, bladder, and rectum. Precision of measurements made using the nasopharynx, esophagus, and bladder is greater than the precision at the axilla, forehead, and rectum, and much higher than the precision at the great toe. Measurements of body temperature using the nasopharynx, esophagus, and bladder are recommended for intraoperative use as providing the best combination of accuracy and precision.

Adult↗
PubMed1982

Halothane biotransformation in obese and nonobese patients.

Serum levels of inorganic fluoride, trifluoroacetic acid, and bromide ion were measured at various time intervals following two hours of halothane anesthesia in 17 morbidly obese and eight nonobese patients. Ionic fluoride, a marker of reductive halothane metabolism, increased in the obese but not the nonobese patients. This is of concern since reductive halothane metabolism is associated with hepatoxicity in animals. In addition, serum bromide levels were higher after 48 h in the obese patients compared to the nonobese patients (mean +/- SE, 1,311 +/- 114 vs. 787 +/- 115 microM, P less than 0.01). Sedative levels of bromide were not attained in any patient. Peak trifluoroacetic acid levels were similar in the two patient groups. Sex age, medication intake, and smoking history had no influence on the halothane metabolite levels found in this study.

Adult↗
PubMed1982

Anesthetic management of the morbidly obese patient.

Anesthetic management should concentrate on various aspects of pre-, intra-, and postoperative care. Particular laboratory studies, such as arterial blood gases, electrocardiogram, selected pulmonary function tests (e.g., ERV), and serum hepatic profile, can be quite useful. Preoperatively, technical difficulties (intravenous and arterial cannulae, operative positioning, and airway assessment), psychologic considerations, and response to preanesthetic medications can be anticipated. Intraoperative concerns encompass the choice of regional versus general anesthesia, anesthetic biotransformation, and variables influencing intraoperative oxygenation (e.g., effects of general anesthesia, operative position, abdominal packing). Postoperative concerns are directed toward minimizing postoperative hypoxemia, peripheral phlebothrombosis, and fluid imbalances. Special caution is needed in operations subsequent to jejunoileal bypass surgery. Specific choices of anesthetic agents and techniques await further clinical and laboratory investigations in this unique subset of the population.

Anesthesia↗
PubMed1982

Enflurane blood-gas solubility: influence of weight and hemoglobin.

The blood-gas partition coefficient of enflurane was measured in nine nonobese and eight morbidity obese patients and correlated with weight, body mass index, and blood hemoglobin. The enflurane blood-gas partition coefficient was lower in the obese patients than in nonobese patients (mean +/- SEM: 2.03 +/- 0.02 versus 1.76 +/- 0.03, respectively, p less than 0.025). There was a negative correlation between enflurane blood solubility and both body mass index and weight (r = 0.59 and -0.55, respectively, p less than 0.01). A positive correlation was found between hemoglobin and the enflurane blood-gas partition coefficient (r = 0.69, p less than 0.01). Equilibrium between inspired and alveolar enflurane concentration should be faster in morbidity obese and anemic patients than in healthy, nonobese patients.

Adult↗
PubMed1982

Inaccuracy of liquid crystal thermometry to identify core temperature trends in postoperative adults.

In 71 adult postsurgical patients, simultaneous measurement of core (tympanic membrane) and shell (liquid crystal adhesive temperature strip) cutaneous temperature was assessed on admission and every 15 minutes throughout the recovery room stay. Tympanic membrane sensors were inserted into the ear and adhesive temperature strips were applied to the forehead. Although temperature strip temperatures on admission to the recovery room were correlated significantly with tympanic membrane temperatures on admission to the recovery room (r = 0.61, p less than 0.001), subsequent readings 15, 30, 45, and 60 minutes after admission demonstrated decreasing correlation coefficients. Moreover, changes in temperature strip temperatures over the first 15, 30, and 45 minutes of monitoring in the recovery room did not correlate significantly with changes in tympanic membrane temperatures over the same time period. These data suggest that shell temperature (temperature strip) is not a reliable or valid trend indicator of core temperature (tympanic membrane) in postanesthetic adults.

Adolescent↗
PubMed1982

Effects of dilution, pressure, and apparatus on hemolysis and flow rate in transfusion of packed erythrocytes.

The purpose of this prospective, randomized study was to measure both the independent and interactional effects of dilution, pressure, and apparatus on flow rates and hemolysis during rapid administration of erythrocytes. Administration of undiluted erythrocytes increased the concentration of plasma-free hemoglobin by as much as 270% per unit under certain conditions. Transfusion flow rates for packed red blood cells were found to be determined by dilution, pressure, and apparatus and varied by as much as 450%. No significant correlation was found between flow rate and hemolysis. Regardless of the external bag pressure applied or the transfusion apparatus used, packed erythrocytes should be diluted (with at least 100 ml of normal saline) to decrease hemolysis and increase flow rate.

Blood Transfusion↗
PubMed1981

General anesthesia for morbidly obese patients--an examination of postoperative outcomes.

Specific postoperative outcomes were assessed in 67 morbidly obese subjects who received general anesthesia for gastric stapling. Each patient was randomly assigned to receive N2O:O2 combined with fentanyl (n = 20), enflurane (n = 24), or halothane (n = 23). Time from last skin stitch until the patient opened eyes on command was significantly less for the fentanyl group (3.0 +/- 0.7 min) than for the enflurane group (13.2 +/- 1.9 min) or the halothane group (17.4 +/- 2.9 min) with P less than 0.05. However, no significant differences in time from last skin stitch to extubation were noted among the fentanyl (16.2 +/- 7.4 min), enflurane (15.2 +/- 1.6 min), and halothane (21.6 +/- 5.8 min) groups (P greater than 0.05). Recovery room (RR) admission temperatures were similar for the three groups: fentanyl, 36.1 +/- 0.1 degrees C; enflurane, 35.7 +/- 0.2 degrees C; and halothane, 36.0 +/- 0.1 degrees C (P greater than 0.05). Total RR time was not significantly different: fentanyl, 108 +/- 6 min, enflurane, 118 +/- 4 min; and halothane, 112 +/- 10 min (P greater than 0.05). In addition, no difference in RR and 24-hour postoperative narcotic (meperidine) requirements was demonstrated among the anesthetic groups. These data suggest that increased lipid solubility of volatile anesthetics (halothane or enflurane) produces neither delayed awakening nor prolonged recovery time in morbidly obese subjects. Considering the early (24 hour) postoperative outcomes studied, there is little to commend one general anesthetic technique over another in the obese subset of the population.

Adult↗