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Biomedical subjects

C G Elliott

Publications and source records attributed to C G Elliott.

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

Pulmonary sequelae in survivors of the adult respiratory distress syndrome.

A spectrum of pulmonary impairment may follow an episode of the adult respiratory distress syndrome (ARDS). At one end of the spectrum is normal pulmonary function; at the opposite is severe impairment. The late pulmonary effects of ARDS usually lie between these two extremes. This article describes the pulmonary sequelae of ARDS, reviews information concerning factors that may influence these sequelae, and provides suggestions for clinical evaluation of ARDS survivors.

Dyspnea↗
PubMed1989

Surgical pathology of the lung in anti-basement membrane antibody-associated Goodpasture's syndrome.

We report the findings of lung biopsies from five patients with anti-basement membrane antibody-associated Goodpasture's syndrome (ABMA-GS). In four patients, pulmonary capillaritis with hemorrhage was found on lung biopsy, confirming that pulmonary capillaritis can be found in ABMA-GS. Although alveolar hemorrhage was the dominant pathologic finding in four of our five patients, all five patients had evidence of injury at the level of the alveolar wall, manifested by hyaline membranes and widening of alveolar walls by edematous connective tissue. In one of our patients, alveolar hemorrhage was only focal, and diffuse alveolar damage was the dominant pathologic finding. This pattern of lung disease has not been previously described in ABMA-GS.

Adult↗
PubMed1989

Impairment after adult respiratory distress syndrome. An evaluation based on American Thoracic Society recommendations.

To test the hypothesis that impairment after the adult respiratory distress syndrome (ARDS) is uncommon, we evaluated 41 ARDS survivors using ATS standards for determination of impairment. A total of 101 trials of pulmonary function tests were obtained between 1 and 388 wk after the onset of ARDS. It was possible to evaluate impairment at 1 yr or more after ARDS in 27 subjects. Eighteen of the 27 were impaired. The percentage of ARDS survivors who were impaired on the basis of FVC, FEV1, FEV1/FVC, and DLCOsb was 50.0, 61.1, 33.3, and 82.4%, respectively. Impairment was mild in 13 (72.2%), moderate in four (22.2%), and severe in one (5.6%). Smoking status had no predictive value in determining impairment. Physiologic indices of ARDS severity (maximal pulmonary artery pressure, lowest static thoracic compliance, and maximal level of PEEP) were found to be significantly different when those impaired 1 yr or more after ARDS were compared with those not impaired. Symptoms were found to have no association with impairment. We conclude that, using ATS criteria, impairment 1 yr or more after ARDS onset is common. Patient characteristics and symptoms after ARDS have no association with impairment 1 yr or more after ARDS onset, whereas physiologic indices of severity during ARDS do.

Adult↗
PubMed1989

The acute administration of vasodilators in primary pulmonary hypertension. Experience from the National Institutes of Health Registry on Primary Pulmonary Hypertension.

The hemodynamic responses to acute vasodilator administration were evaluated in 163 patients who were entered into the National Institutes of Health Registry on Primary Pulmonary Hypertension (PPH) between 1981 and 1985. Of a total of 491 drug administrations in these patients, 135 administrations in 104 patients were performed in a manner acceptable to the Registry. A single vasodilator was tried in 79 patients and more than one vasodilator in 25 patients. Two-thirds of the patients were in New York Heart Association Functional Classes III or IV. When the effects of all vasodilators were grouped together, there were significant decreases from baseline in mean pulmonary artery pressure (60 +/- 2 to 57 +/- 2 mm Hg, p less than 0.05) and total pulmonary resistance index (32.5 +/- 1.7 to 25.1 +/- 1.4 mm Hg/L/min/m2, p less than 0.0001), and increases in cardiac index (2.1 +/- 0.1 to 2.7 +/- 0.1 L/min/m2, p less than 0.0001). Mean systemic blood pressure fell (88 +/- 1 to 79 +/- 1 mm Hg, p less than 0.0001), whereas PaO2 was unchanged (70 +/- 3 to 71 +/- 3 mm Hg, p = NS). A fall in total pulmonary resistance greater than 20% was observed in 55% of the adequate drug trials. Adverse effects occurred in 32 of the total 491 patient-drug trials and were generally minor. Hypotension requiring treatment developed in six patients. There were two deaths attributable to vasodilator administration. Patients who died or had hypotension requiring treatment had higher right atrial pressures than did other treated patients (15 +/- 2 versus 9 +/- 1 mm Hg, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Charcoal lung. Bronchiolitis obliterans after aspiration of activated charcoal.

Activated charcoal usually provides effective and safe treatment for drug overdose. We describe a patient who developed bronchiolitis obliterans and respiratory failure following aspiration of activated charcoal. This patient had a markedly reduced vital capacity with roentgenographic evidence of airtrapping. Chest roentgenograms did not demonstrate the large amount of charcoal identified at postmortem examination.

Adolescent↗
PubMed1989

Heritability estimates of pulmonary function.

To test the hypothesis that there is genetic control of pulmonary function parameters independent of that influencing height, we evaluated 74 pairs of asymptomatic, nonsmoking twins. FVC, FEV1, FEF25-75%, TLCsb, RVsb, Dsb, and D/VA were measured. Pulmonary function indices were adjusted for height using simple linear regression. Mean intrapair differences (unadjusted and adjusted for height) were compared using t tests of independent samples. Within pair, Holzinger's, and Falconer's heritability estimates were calculated using height-adjusted residual values. When total variances of a function parameter were statistically different between monozygotes and dizygotes, the among component heritability estimate was calculated and used as the best indicator of heritability. Following adjustment for height, no measure of pulmonary function which satisfied the requirements of the analysis was found to be significantly heritable.

Adult↗
PubMed1988

Pulmonary veno-occlusive disease associated with severe reduction of single-breath carbon monoxide diffusing capacity.

A 49-year-old woman presented with pulmonary hypertension, profound arterial hypoxemia, and a single-breath carbon monoxide diffusing capacity (DLCO) which was 17% of predicted. History, physical examination, and chest roentgenograms did not suggest the presence of parenchymal pulmonary disease. Spirometry and lung volume measurements were within normal limits. Pulmonary veno-occlusive disease was diagnosed by lung biopsy. This case illustrates the severe reduction of DLCO which can be associated with pulmonary veno-occlusive disease.

Carbon Monoxide↗
PubMed1988

Maximum respiratory pressures in morbidly obese subjects.

Maximum inspiratory and expiratory pressures were measured at residual volume, total lung capacity, and functional residual capacity in 45 morbidly obese patients who on average weighed 183% of their predicted weights. The pressures were compared to determinations made in 25 subjects of similar age whose mean weight was 99% of predicted. For both men and women, pressures generated by control subjects tended to be higher than those produced by obese patients but the differences were not statistically significant. The mean vital capacity and total lung capacity were also similar in the 2 subject groups. The results indicate that despite working constantly against a less compliant chest wall, obese patients do not increase their capacity to generate maximal respiratory pressures.

Adult↗
PubMed1988

Upper airway obstruction following adult respiratory distress syndrome. An analysis of 30 survivors.

To evaluate the effects of current supportive care measures for the adult respiratory distress syndrome (ARDS) upon the upper airway, we studied 30 survivors of ARDS. All patients were interviewed and examined and performed inspiratory and expiratory maximal flow-volume curves more than six months after the onset of ARDS. Three women had developed symptomatic upper airway obstruction due to laryngotracheal stenosis 4 to 12 months after discharge from the hospital. Potential etiologic factors included difficult orotracheal intubation (one) and high tracheal cuff pressures (one). The three survivors who developed laryngotracheal stenoses did not differ from the 27 survivors of ARDS without symptomatic upper airway obstruction with respect to age, duration of tracheal intubation, or maximum level of positive end-expiratory pressure. Each patient with upper airway obstruction required more than one operation for laryngotracheal reconstruction. Although corrective surgery improved airflow, two survivors of ARDS had upper airway obstruction and exertional dyspnea more than five years after the ARDS. We conclude that upper airway obstruction is an important cause of dyspnea and impairment following ARDS. Exertional dyspnea weeks to months following treatment for ARDS suggests the possibility of laryngotracheal stenosis.

Adolescent↗
PubMed1988

Variability of the single-breath carbon monoxide transfer factor as a function of inspired oxygen pressure.

We measured single-breath CO transfer factor (TLCO) and alveolar oxygen partial pressure (PAO2) six times at each of three fractions of inspired oxygen (FIO2) (0.17, 0.21, 0.26) in twelve healthy subjects, to determine whether one FIO2 would have the advantage of producing less variable TLCO results than the others. Measured TLCO was adjusted for the increase in carboxyhaemoglobin during the tests. We found no significant differences in intra- or interindividual variance as a function of test FIO2.

Carbon Monoxide↗
PubMed1988

Normal spirometric values in healthy American Indians.

Spirometric parameters were measured in 300 healthy, lifetime nonsmoking American Indians. When "best" is defined by the highest correlation coefficient and smallest residual standard deviation, the best prediction equations were linear regression equations using only age and height as the independent variables. Visual comparisons of two-dimensional graphic representations of each predictor in these equations with equations commonly used to predict spirometric variables in white persons revealed no substantial differences. However, statistical comparisons, using an analysis of covariance, with data from a previous study of white persons in our laboratory showed the forced vital capacity and forced expiratory volume in 1 second equations for Indian men to be different from the equations for white persons. No statistically significant differences were found between the prediction equations for Indian and white women. The meaning of the statistically significant differences is unclear and they may not have any clinical relevance. Until this issue is resolved we recommend that race-specific equations be used when possible.

Adult↗
PubMed1987

Measurement of anaerobic threshold in chronic airflow obstruction.

We compared determinations of anaerobic threshold (AT) made from measurements of arterial lactate concentration with AT determined from ventilatory response measurements of subjects with chronic airflow obstruction (CAO). Six untrained subjects with CAO performed incremental maximal cycle ergometer tests. Ventilation (VE); O2 uptake (VO2), CO2 output (VCO2); end-tidal CO2 fraction (FETCO2); and end-tidal O2 fraction (FETO2) were measured breath by breath. Arterial lactate concentration was sampled at rest and every 30 s during exercise from an indwelling arterial catheter. For three subjects with more severe airflow obstruction, plots of VE/VO2 and FETO2 failed to detect AT. In contrast, a systematic increase of the respiratory gas exchange ratio across the lung (R) accompanied increasing arterial lactate concentrations in all 6 subjects. We conclude that progressive increases of VE/VO2 and FETO2 cannot be relied upon for the measurement of AT in patients with severe CAO. Progressive increases of R unaccompanied by decreasing FETCO2 detect AT in CAO.

Aged↗
PubMed1987

Diurnal variation of the diffusing capacity of the lung: is it real?

The single-breath diffusing capacity of the lung (DLCO) has been reported to decrease at a rate of 1.2 to 2.2% per hour during usual daytime hours. In an attempt to confirm these findings, we measured DLCO using both single-breath (DLCOs) and rebreathing techniques (DLCOR) in healthy, nonsmoking volunteers over the course of a day and again at different times on different days. Serial testing over a day showed a consistent fall (0.39%/h for DLCOS and 0.56%/h for DLCOR) in DLCO that was explained by increasing carboxyhemoglobin levels (COHb) and decreasing hemoglobin concentrations (Hb). When subjects were tested at different times on different days and compared using a paired t test, there was no change in DLCO over the time of day using either technique. We conclude that there is no diurnal variation in DLCO when adjusted for changes in Hb and COHb. The measurement of COHb levels and Hb concentrations for adjustment of DLCO results is important for correct interpretation of both individual and group studies of DLCO and should be performed whenever possible.

Adult↗
PubMed1987

Prediction of pulmonary function abnormalities after adult respiratory distress syndrome (ARDS).

To determine if measures of ARDS severity during the acute illness correlate with lung function after recovery from ARDS, we regressed lowest total thoracic compliance (CTH), initial intrapulmonary shunt fraction (Qsp/Qt), initial mean pulmonary artery pressure (PAP), maximal level of positive end-expiratory pressure (PEEP), time ventilated (Tvent), and time with FlO2 greater than 0.6 (TO2) against the percent of predicted FVC, TLC, and DLCO of 16 previously healthy, nonsmoking ARDS survivors. Pulmonary function tests were performed more than 1 yr after ARDS. Percent of predicted FVC correlated with CTH (r = 0.66, p less than 0.01) and PAP (r = 0.53, p less than 0.05), and percent of predicted TLC correlated with CTH (r = 0.71, p less than 0.01), PEEP (r = -0.55, p less than 0.05), and Qsp/Qt (r = -0.53, p less than 0.05). Only TO2 correlated with percent of predicted DLCO (r = -0.53, p less than 0.05). Five of 7 ARDS survivors with an abnormal DLCO were supported at FlO2 greater than 0.6 for more than 24 h, whereas all of 9 survivors with a normal DLCO received FlO2 greater than 0.6 for less than 24 h. We conclude that physiologic markers of ARDS severity during the acute illness correlate with residual pulmonary dysfunction after recovery from ARDS. Support with FlO2 greater than 0.6 for more than 24 h appears to be a sensitive and specific predictor of an abnormally reduced DLCO more than 1 yr after ARDS.

Adolescent↗
PubMed1986

Reversible segmental myocardial dysfunction in septic shock.

We report two septic-shock patients who had ECG and echocardiographic changes consistent with myocardial infarction but no evidence of coronary artery disease or myocardial injury at autopsy. The segmental myocardial dysfunction completely resolved in one patient. Because septic shock can cause segmental myocardial dyskinesis, ECG and echocardiographic data may be misleading and should be interpreted cautiously.

Aged↗
PubMed1986

Positive end-expiratory pressure following coronary artery bypass grafting.

Pulmonary dysfunction commonly follows open heart surgery. To evaluate the effects of positive end-expiratory pressure (PEEP) upon the course and severity of impaired oxygen transfer and roentgenographic evidence of atelectasis after coronary artery bypass grafting (CABG), we randomly assigned 44 patients to positive pressure ventilation and 0, 5, or 10 cm H2O PEEP. Study groups did not differ with respect to preoperative P(A-a)O2 or time on cardiopulmonary bypass. We observed a significant reduction of P(A-a)O2 during positive pressure ventilation with 10 cm H2O PEEP and FIO2 = 0.6 (182 +/- 6 vs 135 +/- 7 mm Hg, p less than .005). Following extubation, P(A-a)O2 measurements of the three groups did not differ when compared 24, 48, 72, 96, or 120 hours after surgery. Roentgenographic atelectasis scores did not differ on the fifth postoperative day. Five days after CABG, P(A-a)O2 exceeded preoperative P(A-a)O2 (29 +/- 1 vs 18 +/- 1 mm Hg, p less than .001), although the roentgenographic distances from hemidiaphragm to lung apex were unchanged (21.2 +/- 0.9 vs 22.0 +/- 0.9 cm). We conclude that routine PEEP improves pulmonary oxygen transfer but, once discontinued, PEEP offers no sustained beneficial effect upon impaired oxygen transfer or roentgenographic evidence of atelectasis following CABG.

Blood Gas Analysis↗
PubMed1986

Spirometry as a preoperative screening test in morbidly obese patients.

We performed spirometry on 114 morbidly obese patients considered for gastric bypass surgery to assess its efficacy as a preoperative screening test. One hundred eight subjects underwent surgery, and 61 patients returned for repeat spirometry 1 year later. The average preoperative forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and mid flow (FEF25-75%) were 100% of predicted. Spirometry identified no more of our obese subjects as abnormal than would have been identified in a group of healthy, nonobese individuals. Each surgical case was reviewed. An abnormal preoperative spirogram did not identify the patients who experienced postoperative complications. Weight loss was associated with very small increases in FVC (300 ml) and FEV1 (245 ml). Preoperative spirometric testing is not indicated in morbidly obese patients with no other identifiable risk factors for postoperative respiratory complications.

Adult↗