Debapriya Datta

Hypothyroidism and Failure To Wean in Patients Receiving Prolonged Mechanical Ventilation at a Regional Weaning Center

OBJECTIVE Hypothyroidism is cited as an uncommon cause of ventilator-dependent respiratory failure. The objective of this study was to determine the incidence of hypothyroidism in patients with respiratory failure, receiving prolonged mechanical ventilation (PMV) with failure to wean, referred to a regional weaning center (RWC) for weaning. SETTING RWC. DESIGN Retrospective. METHODS Medical records were reviewed of 173 patients admitted to this RWC between January 1999 and March 2002. One hundred forty patients were noted to have had screening serum thyroid stimulating hormone (TSH) levels obtained at admission. Records of these patients were further evaluated. The following data were abstracted: age, sex, body mass index, serum TSH levels, number of patients with previously diagnosed hypothyroidism, and number of patients with hypothyroidism diagnosed clinically and by laboratory tests following admission to the RWC. Primary outcome was liberation from PMV, which was defined as being off ventilatory support for > 1 week. Univariate analysis was performed to determine relation between serum TSH levels and outcome; p < 0.05 was deemed statistically significant. RESULTS Of 140 patients studied, 67 were male (48%) and 73 were female (52%), with a mean age of 66 + 15 years (+/- SD). Only one patient had a history of previously diagnosed hypothyroidism. A clinical diagnosis of hypothyroidism was made in 4 of 140 patients (3%) following admission. Serum TSH levels ranged from 0.19 to 121 mU/L in the studied subjects. Seventeen of 140 patients (12%) had elevated serum TSH levels. Serum tri-iodothyronine and/or thyroxine levels confirmed diagnosis of hypothyroidism in four of these patients (3%). Patients with newly diagnosed hypothyroidism were treated with thyroid supplements, and three patients were liberated from PMV while one patient died from other medical causes. Of the 140 patients, 92 patients (67%) were liberated from PMV while 48 patients (33%) could not be weaned. Mean serum TSH levels were 4.2 + 13 mU/L in the liberated patients and 4 + 4.7 mU/L in the patients who could not be weaned (p = 0.25). CONCLUSION Hypothyroidism is an uncommon cause of failure to wean in patients receiving PMV (with an incidence of 3%). However, it is a potentially treatable cause and should be considered in all patients who fail to wean. Serum TSH level does not appear to affect successful weaning from PMV.

An Evaluation of Nebulized Levalbuterol in Stable COPD

BACKGROUND Levalbuterol, the R-isomer of albuterol, has advantages over racemic albuterol in asthma; however, the effectiveness of this beta-agonist in COPD has received little attention. OBJECTIVES To evaluate the effectiveness of a single dose of nebulized levalbuterol in COPD. DESIGN A randomized, double-blind, placebo-controlled trial comparing nebulized levalbuterol to racemic albuterol, combined racemic albuterol and ipratropium, and placebo. PATIENTS Thirty patients with stable COPD (FEV(1) between 45% and 70% of predicted) were studied. METHODS After withholding usual bronchodilator medications for appropriate washout periods, patients were randomized on separate visits to receive single doses of each the following nebulized bronchodilator medications: (1) levalbuterol, 1.25 mg; (2) racemic albuterol, 2.5 mg; (3) combined racemic albuterol, 2.5 mg, and ipratropium, 0.5 mg; or (4) placebo. FEV(1), FVC, pulse rate, and oxygen saturation were measured at baseline, 0.5 h following nebulization, and hourly for 6 h. Hand tremor, using a 7-point scale, was measured at baseline, 0.5 h, 1 h, and 2 h. Treatment-placebo differences were analyzed using repeated-measures analysis of variance and least-squares means. RESULTS The mean age (+/- SD) of patients was 69 +/- 15 years. Mean FEV(1) was 1.15 +/- 0.49 L. By 0.5 h following study drug administration, all three nebulized bronchodilator treatments led to similar, significant improvements in FEV(1) compared to placebo. These effects persisted at 1 h and 2 h for all three treatments; however, by 3 h, only the combined albuterol/ipratropium group had a mean change in FEV(1) significantly greater than placebo. There were no significant differences between bronchodilator groups at any time period. A mild increase in pulse rate was observed in all treatment groups. There were no significant treatment-placebo differences in oxygen saturation or hand tremor. CONCLUSION For single-dose, as-needed use in COPD, there appears to be no advantage in using levalbuterol over conventional nebulized bronchodilators.

Is the Present Definition of Health Care–Associated Pneumonia the Best Way to Define Risk of Infection with Antibiotic-Resistant Pathogens?

Health care-associated pneumonia (HCAP) is associated with an increased risk of infection with multidrug-resistant pathogens compared with community-acquired pneumonia. Recent studies suggest that the designation of HCAP is a poor predictor of resistant pathogens and that antibiotic coverage for multidrug-resistant pathogens is not necessary in all patients with HCAP. This article reviews existing literature on HCAP, discusses the utility of the current definition of HCAP in identifying patients at risk for potentially drug-resistant pathogens, and compares how well the current HCAP designation predicts the risk of drug-resistant pathogens with other proposed algorithms for doing so.

Pneumocystis carinii pneumonia: the time course of clinical and radiographic improvement.

OBJECTIVES The purpose of this study was to compare the time course of clinical and radiographic improvement in patients with Pneumocystis carinii pneumonia (PCP), and evaluate the usefulness of early follow-up chest radiographs (CXRs) in these patients. DESIGN Retrospective, chart review. METHODS The medical records of 36 episodes of confirmed PCP among 28 patients were reviewed. Clinical parameters of improvement were defined as follows: (1) a decrease in temperature by 0.5 degrees C, (2) a decrease in respiratory rate by 25%, and (3) a 2% improvement in arterial oxygen saturation, as measured by pulse oximetry, in the setting of an unchanged amount of supplemental oxygen or a reduction in supplemental oxygen. A patient was defined as clinically improving when all three of these criteria were met. All CXRs were graded by radiologists, specifically for the study, as normal or abnormal and improved, worsened, or unchanged from the initial CXR. RESULTS Clinical improvement was noted during 30 of 36 episodes of PCP (83%) at a mean of 4.5 +/- 2.5 days (+/- SD). There was improvement in the CXR finding during the hospital stay during 15 of 36 episodes (42%), at a mean of 7.7 +/- 4.5 days. Radiographic resolution preceded clinical resolution in only four cases (11%). Excluding seven patients who received ventilatory support, the median number of CXRs per patient was four (range, two to nine CXRs). CONCLUSION We conclude that radiographic improvement of PCP lags behind clinical improvement.

Cardiopulmonary exercise testing in the assessment of exertional dyspnea.

Dyspnea on exertion is a commonly encountered problem in clinical practice. It is usually investigated by resting tests such as pulmonary function tests and echocardiogram, which may at times can be non-diagnostic. Cardiopulmonary exercise testing (CPET) measures physiologic parameters during exercise which can enable accurate identification of the cause of dyspnea. Though CPET has been around for decades and provides valuable and pertinent physiologic information on the integrated cardiopulmonary responses to exercise, it remains underutilized. The objective of this review is to provide a comprehensible overview of the underlying principles of exercise physiology, indications and contraindications of CPET, methodology and interpretative strategies involved and thereby increase the understanding of the insights that can be gained from the use of CPET.

Subacute Right Ventricle Perforation by Pacemaker Lead Presenting with Left Hemothorax and Shock

Cardiac perforation by pacemaker is a rare but potentially fatal complication. Acute perforations occurring within twenty-four hours of insertion of pacemaker can lead to hemopericardium, cardiac tamponade, and death. Hemothorax occurring as an acute complication of pacemaker insertion is reported but extremely rare. Previously, hemothorax and shock as a subacute complication following pacemaker insertion have not been reported. We report the case of an 85-year-old patient who presented with shock from hemothorax caused by pacemaker perforation, two weeks after insertion. Device interrogation showed normal function. Chest X-ray and echocardiogram missed lead dislocation and the diagnosis was made on computed tomogram (CT) of the chest. Following surgical repair, a new ventricular pacemaker was placed transvenously in the right ventricular septum. This case illustrates that CT scan of the chest should be performed in all patients in whom cardiac perforation by pacemaker is suspected but not diagnosed on chest X-ray and echocardiogram. Normal functioning of pacemaker on device interrogation does not exclude perforation.

Can Creatinine Height Index Predict Weaning and Survival Outcomes in Patients on Prolonged Mechanical Ventilation After Critical Illness

Objective: Malnutrition is common in chronic critically ill patients on prolonged mechanical ventilation (PMV) and may affect weaning. The creatinine height index (CHI), which reflects lean muscle mass, is regarded as the most accurate indicator of malnutrition. The objective of this study was to determine the impact of CHI in comparison with other traditional nutritional indices on successful weaning and survival in patients on PMV after critical illness. Methods: Records of 167 patients on PMV following critical illness, admitted for weaning, were reviewed. Parameters studied included age, gender, body mass index (BMI), percentage ideal body weight (%IBW), total protein, albumin, prealbumin, hemoglobin (Hb), and cause of respiratory failure. Number successfully weaned and number discharged alive and time to wean and time to discharge alive were determined from records. The CHI was calculated from 24-hour urine creatinine using a standard formula. Unpaired 2-sample t test was performed to determine the association between the studied nutritional parameters and outcomes. Predictive value of studied parameters for successful weaning and survival was determined by multivariate logistic regression analysis to model dichotomous outcome of successful weaning and survival. Results: Mean age was 68 ± 14 years, 49% were males, 64% were successfully weaned, and 65.8% survived. Total protein, Hb, and CHI had a significant impact on successful weaning. Weight, %IBW, BMI, and CHI had a significant effect on survival. Of all parameters, CHI was most strongly predictive of successful weaning and survival. Conclusions: The CHI is a strong predictor of successful weaning and survival in patients on PMV.

Spontaneous Tumor Lysis Syndrome due to Uterine Leiomyosarcoma with Lung Metastases

Tumor lysis syndrome (TLS) is an oncologic emergency characterized by a combination of metabolic derangements (hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia) caused by rapid turnover from cell destruction in certain cancers. These metabolic derangements can lead to seizures, cardiac arrhythmias, renal failure, and death. TLS is usually seen after the initiation of chemotherapy for hematologic malignancies. TLS occurring spontaneously, without initiation of chemotherapy, is rare and its occurrence in solid tumors is rarer still. We report a case of spontaneous TLS in a patient with leiomyosarcoma of the uterus, with metastasis to lung. Such a case has never been reported before.

Acute Respiratory Failure due to Neuromyelitis Optica Treated Successfully with Plasmapheresis

Neuromyelitis Optica (NMO) is a demyelinating autoimmune disease involving the central nervous system. Acute respiratory failure from cervical myelitis due to NMO is known to occur but is uncommon in monophasic disease and is treated with high dose steroids. We report a case of a patient with NMO who developed acute respiratory failure related to cervical spinal cord involvement, refractory to pulse dose steroid therapy, which resolved with plasmapheresis.

A 46-Year-Old Woman With Persistent Asthma and Lung Masses

46-year-old woman presented with diffi culty breathing with exertion for the last few months. She had recently been diagnosed with asthma and was prescribed inhaled bronchodilators without significant improvement. She was using rescue bronchodilators three times a day. She denied fevers, chronic cough, hemoptysis, chest pain, nasal congestion, or postnasal drip. There was no history of nocturnal symptoms, heartburn, weight loss, or loss of appetite. She had previously never had a chest radiograph. Her past medical history was otherwise negative. She was using an albuterol metered-dose inhaler as needed. She did not smoke or use any illicit substances. She was unemployed and had no pets. Family history was unremarkable.