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Biomedical subjects

T A Dillard

Publications and source records attributed to T A Dillard.

At least 19 recordsLinked to original sources
PubMed1999

Delayed traumatic hemothorax on ticlopidine and aspirin for coronary stent.

A 64-year-old man presented with worsening dyspnea on exertion and hemothorax of the left chest 7 days after discharge from the hospital on ticlopidine and aspirin after coronary stent placement to his left circumflex artery. He had suffered traumatic rib fractures to the seventh, eighth, and ninth left ribs 28 days before this presentation and 21 days before starting the ticlopidine. Results of chest radiography at discharge 7 days earlier while on aspirin and after brief IV heparin had been negative except for minimal atelectasis and rib fractures barely visible on posteroanterior view. The delayed hemothorax had lowered the peripheral blood hematocrit to 23% and required tube thoracostomy drainage and blood transfusion. The delayed traumatic hemothorax in this case occurred on treatment with ticlopidine and did not recur with continuation of aspirin alone.

Aspirin↗
PubMed1999

Bronchial mucormycosis with progressive air trapping.

A previously healthy 70-year-old woman developed fever, cough, and exertional dyspnea. Her symptoms progressed over a 2-month period despite treatment by her primary care physician with 2 courses of oral antibiotics and the addition of prednisone. Hypoxemia and the finding of hyperglycemia with mild ketoacidosis led to hospital admission. Serial chest radiographs demonstrated diffuse heterogeneous pulmonary opacities and progressive air trapping in the right lower lobe. Fiberoptic bronchoscopy revealed a deep penetrating ulcer with exposed bronchial cartilage of the bronchus intermedius and dynamic airway obstruction with complete closure during expiration. Biopsy of the ulcer revealed Rhizopus arrhizus. Respiratory failure stabilized with the patient on conventional mechanical ventilation and receiving amphotericin B. Before surgery could be performed, Pseudomonas aeruginosa pneumonia and septic shock developed, and the patient died.

Aged↗
PubMed1998

Multiple organ toxicity from addition of erythromycin to long-term lovastatin therapy.

A patient who had taken lovastatin for 7 years received erythromycin before dental procedures. Multiple organ toxicity developed, manifested as rhabdomyolysis, acute renal failure, pancreatitis, ileus, livedo reticularis, and elevated aminotransferase values, without liver injury. No previous reports have identified multiple organ injury of this magnitude. A computer literature search identified only three other reported instances of erythromycin and lovastatin interaction. Manifestations in these previous cases consisted of rhabdomyolysis in all three, as well as elevated aminotransferase values and acute renal failure in two cases. In all the cases, the clinical presentation of organ toxicity occurred after the cessation of erythromycin therapy between day 1 and day 5. Advanced age and chronic renal insufficiency were identified as potential risk factors for drug interaction. Health care professionals should be aware of the potential interaction between these two commonly prescribed drugs, which can mimic sepsis.

Acute Kidney Injury↗
PubMed1998

Lung function during moderate hypobaric hypoxia in normal subjects and patients with chronic obstructive pulmonary disease.

BACKGROUND: We sought to describe changes in spirometric variables and lung volume subdivisions in healthy subjects and patients with chronic obstructive pulmonary disease (COPD) during moderate acute hypobaric hypoxia as occurs during air travel. We further questioned whether changes in lung function may associate with reduced maximum ventilation or worsened arterial blood gases. METHODS: Ambulatory patients with COPD and healthy adults comprised the study populations (n = 27). We obtained baseline measurements of spirometry, lung volumes and arterial blood gases from each subject at sea level and repeated measurements during altitude exposure to 8000 ft (2438 m) above sea level in a man-rated hypobaric chamber. RESULTS: Six COPD patients and three healthy subjects had declines in FVC during altitude exposure greater than the 95% confidence interval (CI) for expected within day variability (p < 0.05). Average forced vital capacity (FVC) declined by 0.123 +/- 0.254 L (mean +/- SD; 95% CI = -0.255, -0.020; p < 0.05) for all subjects combined. The magnitude of decline in FVC did not differ between groups (p > 0.05) and correlated with increasing residual volume (r = -0.455; <0.05). Change in maximum voluntary ventilation (MVV) in the COPD patients equaled -1.244 +/- 4.797 L x min(-1) (95% CI = -3.71, 1.22; p = 0.301). Decline in maximum voluntary ventilation (MVV) in the COPD patients correlated with decreased FVC (r = 0.630) and increased RV (r = -0.546; p < 0.05). Changes in spirometric variables for patients and controls did not explain significant variability in the arterial blood gas variables PaO2, PaCO2 or pH at altitude. CONCLUSIONS: We observed a decline in forced vital capacity in some COPD patients and normal subjects greater than expected for within day variability. Spirometric changes correlated with changes in reduced maximum voluntary ventilation in the patients but not with changes in resting arterial blood gases.

Adult↗
PubMed1997

Bedside videoscopic placement of feeding tubes: development of fiberoptics through the tube.

OBJECTIVE: Transpyloric small intestine feeding tube placement can be difficult and tedious. Currently accepted techniques are associated with disadvantages and risk. The purpose of this study is to describe the development of a new technique: bedside videoscopic placement using fiberoptics through the tube. DESIGN: Prospective, descriptive case study. SETTING: Intensive care unit in a teaching hospital. PATIENTS: Subjects were divided into two groups: a) group 1: eight healthy volunteers (seven male, one female); b) group 2: nine critically ill patients (six male, three female; eight of these patients were intubated). INTERVENTIONS: Standard 12-Fr (4.0-mm) feeding tubes (n = 19) were placed. Two patients from group 2 had feeding tubes placed on two separate occasions. The feeding tubes were inserted by the oral (n = 8) or nasal (n = 11) route under direct vision, using a 6.7-Fr (2.2-mm) fiberoptic scope through the feeding tube. MEASUREMENTS AND MAIN RESULTS: We visualized enteric structures clearly through the feeding tube in all subjects and patients. Based on visual landmarks, we advanced the feeding tube through the pylorus and into the duodenum in all individuals. Transpyloric tube placement was confirmed videoscopically (n = 19) and radiographically (n = 18). In three subjects from group 1, the feeding tube entered the first part of the duodenum, while, in the remainder of the subjects, the tube passed into or beyond the second portion of the duodenum. In eight (73%) of 11 attempts on the nine critically ill patients from group 2, the feeding tubes were advanced to the distal duodenum or jejunum. The time required for placement in group 2 ranged from 2 to 43 mins (mean 18 +/- 12 [SD]). The feeding tubes remained in place 10 +/- 4 days and patients met their estimated caloric needs within 24 hrs. Residual volumes of nutrition in the small bowel were < 5 mL. There were no documented episodes of aspiration. CONCLUSION: This new technique has the potential for rapid, accurate, and safe feeding tube placement in patients requiring nutritional support.

Adult↗
PubMed1997

Do-not-resuscitate decisions in the medical ICU: comparing physician and nurse opinions.

STUDY OBJECTIVE: To determine how soon after admission to a medical ICU physicians and nurses decide that attempts at resuscitation are inappropriate and how frequently physicians and nurses disagree about do-not-resuscitate (DNR) decisions. DESIGN: Prospective, opinion survey of care providers. SETTING: Ten-bed adult medical ICU in a university-affiliated tertiary care referral hospital. PATIENTS: Consecutive adult medical ICU admissions. INTERVENTIONS: Over 10 months, physicians and nurses were surveyed independently every day regarding their opinions about DNR issues on each patient in the ICU. MEASUREMENTS: ICU day when DNR order was deemed appropriate by either physicians or nurses. RESULTS: Of 368 consecutive admissions, 84 (23%) patients were designated DNR during their ICU stay. In 6 of these 84 cases (7%), the responsible nurse did not agree that DNR orders were appropriate. In the remaining 78 patients designated DNR, the median time for physicians to recommend DNR (median, 1 day; range, 0 to 22 days) was not significantly different from the median time for nurses (median, 1 day; range, 0 to 13 days); (p=0.45). For the 284 patients not designated DNR, physicians and nurses both believed DNR was appropriate in 14 cases (5%), but a DNR order was not written five times (2%) because there was not time to do so and nine times (3%) because patient or family did not concur. Physicians and nurses disagreed about a DNR recommendation in 33 of the 284 patients not designated DNR (12%). Physicians were more likely to believe that DNR was appropriate than were nurses (p<0.0005), with physicians alone recommending DNR 29 times (10%) and nurses alone favoring DNR in four cases (1%). CONCLUSIONS: At our institution, recognition of DNR appropriateness by nurses and physicians occurs over a similar time frame. However, physicians are more likely to recommend DNR in cases of disagreement between nurses and physicians.

Aged↗
PubMed1996

Does hemodilution exist? Effects of saline infusion on hematologic parameters in euvolemic subjects.

The effects of intravenous fluids on hematocrit are debated. We sought to determine whether maintenance or bolus fluid therapy causes a significant change in the hematocrit and other hematologic parameters included in the complete blood count. Nine subjects completed a randomized three-period crossover designed trial in which they were given no fluid, maintenance fluid, or a bolus of fluid followed by maintenance fluid. We measured complete blood counts at baseline, 1 hour, 4 hours, and 8 hours. In the bolus fluid trial, the hemoglobin and hematocrit values (mean +/- SEM) decreased by a maximum of 1.5 +/- 0.1 g/dL and 4.1 +/- 0.3% at 1 hour. There was no difference in hemoglobin or hematocrit during the no fluid or maintenance fluid treatments. No significant changes occurred in white blood cell or platelet counts. We demonstrated that maintenance fluid infusions do not significantly after the complete blood count. Saline bolus is associated with a significant decrease in hemoglobin and hematocrit, but these parameters trend toward baseline over time.

Adult↗
PubMed1996

Arm span-height relationships in patients referred for spirometry.

Arm span has been proposed as a surrogate for standing height in the prediction of lung volumes in patients with thoracic deformities or who are unable to stand. The relationship between arm span and height has previously been reported as either a fixed ratio unaffected by age or as a regression equation in which the ratio varies as a function of age. We studied the relationship between standing height, arm span, race, sex, and age in 202 patients (ages 20 to 88 yrs) referred for screening spirometry. Multiple linear regression analysis found arm span, race, sex, and age to be predictive of standing height (r2 = 0.8659, p < 0.0001). Subgroup analysis revealed that age was a significant factor among males of either race, but not among females of either race. Fixed arm span to height ratios were also calculated for each group and may be used to estimate standing height with reasonable accuracy except at extremes of stature.

Adult↗
PubMed1996

Sulfasalazine pulmonary toxicity in ulcerative colitis mimicking clinical features of Wegener's granulomatosis.

The centrally accentuated antineutrophil cytoplasmic antibody test (c-ANCA) is widely regarded as a sensitive and specific marker for Wegener's granulomatosis (WG). There are increasing reports, however, of false-positive c-ANCAs, usually in the setting of other vasculidities. We report a case of a 27-year-old man with ulcerative colitis who developed pulmonary symptoms, peripheral nodular lung infiltrates, and an elevated c-ANCA suggesting WG. Chest CT and open lung biopsy specimens were consistent with WG. The symptoms and pulmonary infiltrates resolved after discontinuation of sulfasalazine therapy. The c-ANCA remained elevated due to the occurrence of false-positive values in ulcerative colitis. We conclude sulfasalazine toxicity can mimic clinical aspects of WG and that c-ANCA testing should be interpreted with caution in patients with ulcerative colitis.

Adult↗
PubMed1996

Pulse oximetry correction for smoking exposure.

Pulse oximetry oxygen saturation (SpO2) does not distinguish carboxyhemoglobin (COHb) from oxyhemoglobin (O2Hb), giving a false impression of the apparent degree of oxyhemoglobin saturation in smokers who have elevated levels of COHb. We questioned whether accounting for smoking exposure history could improve description of pulse oximetry by correcting for COHb levels. We evaluated smoking history and %SpO2 as predictors of %O2Hb and %COHb by CO-oximetry of arterial blood in 18 actively smoking and 18 age-matched nonsmoking patients in a clinical pilot study. The difference between %SpO2 and %O2Hb was significantly greater (p < 0.001) in the smokers (5.6 +/- 3.1) than the nonsmokers (2.1 +/- 2.1). This difference correlated with %COHb (rp = 0.789; p < 0.001) and the smoking exposure score (SES, rp = 0.621; p < 0.001), a six-point index we developed based on whether patients were active smokers, refrained from smoking prior to testing, or were exposed to passive smoking in the home or workplace. The following formula summarizes the correction: %O2Hb = 0.882[%SpO2] - 0.968[SES] + 9.245 (rp = 0.841; SES = 2.478; p < 0.001). This pilot study suggests that smoking exposure history correlates with COHb levels and that correction for smoking exposure improves the accuracy of pulse oximetry.

Carboxyhemoglobin↗
PubMed1996

Effect of upright and supine posture on hypoxemia during air transport.

BACKGROUND: Change in body position can cause hypoxemia at sea level in patients with lung diseases. Because of concern for the added risk of hypoxemia during air transport, we investigated the effect of body position on arterial oxygen partial pressure (PaO2) in individuals with lung disease under conditions of hypobaric hypoxia. METHOD: The study groups consisted of 8 patients with chronic obstructive lung disease, 4 patients with interstitial lung disease, and 6 healthy subjects. We obtained samples from radial artery catheters at sea level (SL) and altitude (ALT) simulation of 8000 ft (2438 m) in a hypobaric chamber in supine and upright postures. RESULTS: Altitude exposure did not result in a significant change in mean supine minus mean upright PaO2 (dPaO2); however, some individuals had large changes at SL. Moreover, the variance for dPaO2 was significantly smaller at ALT compared to SL with all groups combined (F test, p < 0.05). We found no correlation between dPaO2 at SL vs. ALT (p = 0.293; r = 0.262; n = 18). At both SL and ALT, dPaCO2 correlated negatively with dpH. At SL, dPaO2 did not correlate with either dPaCO2 or dpH; at ALT dPaO2 correlated with dpH (p < 0.05) and correlated negatively with dPaCO2 (p < 0.01). CONCLUSION: We conclude that significantly less postural variation in PaO2 occurs at moderate ALT compared to SL. In our patients with diffuse bilateral pulmonary disease, postural change did not contribute significantly to hypoxemia experienced at ALT. We infer that greater ventilatory response to hypoxemia at ALT in either posture may explain this finding.

Adult↗
PubMed1995

The preflight evaluation. A comparison of the hypoxia inhalation test with hypobaric exposure.

STUDY OBJECTIVES: We sought to compare arterial oxygen partial pressure (PaO2) relationships between a 15.1% hypoxia inhalation test (HIT) at sea level and a hypobaric chamber exposure equivalent to 2,438 m (8,000 feet) of altitude above sea level in patients with chronic obstructive pulmonary disease (COPD) and healthy subjects. DESIGN: Comparison of physiologic variables before and during intervention. SETTING: A referral-based pulmonary disease clinic at a US Army medical center in a metropolitan area. SUBJECTS: The study included three groups: group 1, 15 patients, 3 women and 12 men, with COPD (forced expiratory volume in the first second [FEV1, mean +/- SD], 41 +/- 14% of predicted); group 2, 9 healthy men; and group 3, 18 men with COPD (FEV1, 31 +/- 10% of predicted) previously reported in detail. INTERVENTIONS: We evaluated each group at sea level followed by one of two different types of hypoxic exposures. Group 1 received exposure to 15.1% oxygen at sea level, the HIT. Groups 2 and 3 received hypobaric chamber exposure equivalent to 2,438 m (8,000 feet) above sea level. MEASUREMENTS AND MAIN RESULTS: For all three groups combined, the arterial oxygen tension at sea level (PaO2SL) explained significant variability in PaO2 during hypoxic exposure according to the following formula: PaO2 during exposure = 0.417 (PaO2SL)] + 17.802 (n = 42; r = 0.756; p < 0.001). Neither the type of hypoxic exposure (HIT vs hypobaric), status as patient vs control, sex, nor age explained significant variability in PaO2 during hypoxia exposure after inclusion of PaO2SL as a covariate in analysis of variance. Subsequent analysis revealed that forced expiratory spirometric variables FEV1 and FEV1 to FVC ratio served as second order covariates with PaO2SL to improve description of PaO2 during hypoxia exposure for the combined samples (n = 42; p < 0.05). Analysis of residuals from regression analysis revealed approximately normal distribution. CONCLUSIONS: The PaO2 relationships did not differ between the 15.1% HIT at sea level and hypobaric exposures of 2,438 m (8,000 feet) above sea level. Normal subjects and patients with COPD formed a single relationship. The present study extends descriptive models to a larger range of subjects. Regression models have definable accuracy in predicting PaO2 during hypoxia exposure that increases with inclusion of spirometric variables.

Adult↗
PubMed1995

Adherence to established guidelines for preoperative pulmonary function testing.

Guidelines for ordering preoperative spirometry have been proposed by GM Tisi (1979) and more recently by the American College of Physicians (ACP). Requests for preoperative spirometries represent a significant portion of all requests for screening spirometry at our institution and utilize significant man-hours of technician time. We determined the percentage of these requests that did not meet the ACP guidelines and characterized why these requests were being generated. We sampled 441 screening spirometries performed by the Walter Reed Pulmonary Function Laboratory over a 4-week period. One hundred thirty-eight (31%) of these were done preoperatively and complete data were available in 135 cases. Patients in the analyzed group had a mean age of 59 years (+/- 14 years), ranging from 20 to 84 years of age. Fifty-two (39%) requests did not meet ACP guidelines. Most of these requests were associated with either normal spirometry (n = 34) or only mild spirometric abnormalities (n = 14). Spirometry revealed severe obstruction in only one case when the request was not indicated. No cases of moderate obstruction, severe restrictive pattern, or possible upper airway obstruction were found in the group of requests in which spirometry was not indicated. Of the requests that did not meet ACP guidelines, 21 met Tisi's broader guidelines. Most of these requests were found exclusively in patients older than 70 years of age (n = 13) and the morbidly obese (n = 4). Of the 31 studies that did not meet either set of guidelines, 25 occurred in asymptomatic, current, or prior smokers. In conclusion, during a 4-week study period at our institution, 39% of preoperative spirometry requests did not meet ACP guidelines. Most of the patients had been referred because of age greater than 70 years, morbid obesity, and a current/prior history of smoking. However, the literature does not support obtaining preoperative spirometry in such patients except for those undergoing only lung resection. We recommend stricter adherence to the ACP guidelines as a means of decreasing the number and cost of unnecessary spirometries being performed.

Adult↗
PubMed1995

Digital clubbing associated with polymyositis and interstitial lung disease.

Clubbing of the fingers is commonly associated with interstitial lung diseases (ILDs). Although ILD occurs in as many as 40% of patients with polymyositis/dermatomyositis (PM/DM), clubbing of the digits has never been reported to occur in patients with PM/DM and ILD. We report the first case of clubbing associated with PM/DM and ILD.

Adult↗
PubMed1994

Pyogenic arthritis complicating varicella infection.

Arthritis has not previously been reported as a complication in adult patients with chickenpox. In pediatric patients, the arthritis that complicates chickenpox is most commonly aseptic but does rarely result from bacterial infection. We report the case of a 21-year-old man who developed acute monoarticular septic arthritis due to Lancefield Group A beta-hemolytic streptococci. Despite the more common viral cause of arthritis in pediatric patients, physicians should not attribute arthritis associated with varicella in adults to a viral cause without diagnostic arthrocentesis.

Adult↗
PubMed1994

Impact of using stated instead of measured height upon screening spirometry.

This study examined the impact of using stated height instead of measured height on predicted normal values and clinical interpretation of screening spirometry in an outpatient referral population. In a prospective fashion, we evaluated 210 patients, 20 to 89 yr of age, referred for spirometry to our pulmonary function laboratory by obtaining both stated height (HTs) and measured height (HTm). The mean difference between stated and measured height progressively increased with age, from 0.80 cm (20 to 29 yr; p = 0.01) to 5.70 cm (80 to 89 yr; p < 0.001). For men and women, use of HTs instead of HTm produced a mean difference for all ages in computing predicted FEV1 and FVC values of 3.9 and 4.3%, respectively. This effect was more prominent in the older age groups (80 to 89 yr, n = 30); mean differences were 11.0% (211 ml) and 11.7% (303 ml), respectively. Use of HTs instead of HTm altered the detection of restriction by reduced FVC in 17 patients and the detection of obstruction by reduced FEV1/FVC ratio in four patients. Use of HTs altered the clinical assessment of severity by FEV1 in 15 of 108 (13.9%) obstructed patients and altered the assessment of severity by FVC in 11 of 32 (34.4%) restricted patients, with older patients more frequently affected than younger patients. We conclude that the use of stated height instead of measured height in the performance of screening spirometry can have significant impact on the calculation of predicted normal values. These discrepancies can potentially influence the clinical interpretation of screening spirometry, affecting the detection of abnormality and the assessment of severity of disease, particularly among older patients.

Adult↗
PubMed1993

Hemodynamic effects of altitude exposure and oxygen administration in chronic obstructive pulmonary disease.

PURPOSE: Cardiovascular events are the leading cause of death during air travel. Because patients with chronic obstructive pulmonary disease (COPD) develop severe hypoxemia at altitude, we sought to determine whether changes in systemic hemodynamics may contribute to health risks during hypobaric hypoxia. PATIENTS AND METHODS: We recorded radial artery catheter blood pressure, cardiac frequency, and cardiac ectopy in 18 men (aged 68 +/- 6 years, mean +/- SD) with severe COPD (forced expiratory volume in 1 second 0.97 L +/- 0.32 L) at sea level, after 45 minutes of steady-state hypobaric hypoxia at 2,438 m in a hypobaric chamber, and after oxygen supplementation at 2,438 m. RESULTS: Mean arterial pressure (mm Hg), systolic blood pressure (SBP), diastolic blood pressure, and pulsus paradoxus during acute hypobaric exposure did not differ from baseline. During oxygen supplementation, SBP declined (p = 0.028). Decreases in pulsus paradoxus and pulse pressure were noted on oxygen (p < 0.05). We found no changes in cardiac frequency. Cardiac ectopy was uncommon; for one subject, ectopy increased with hypobaric hypoxia and decreased with oxygen administration. CONCLUSION: Vasopressor responses to hypoxia do not add to the risk of air travel in patients with severe COPD. Supplemental oxygen may cause beneficial hemodynamic changes in patients with COPD during acute hypobaric exposure.

Aerospace Medicine↗