Yao-Kuang Wu

Open lung biopsy in early-stage acute respiratory distress syndrome.

IntroductionAcute respiratory distress syndrome (ARDS) has heterogeneous etiologies, rapid progressive change and a high mortality rate. To improve the outcome of ARDS, accurate diagnosis is essential to the application of effective early treatment. The present study investigated the clinical effects and safety of open lung biopsy (OLB) in patients with early-stage ARDS of suspected non-infectious origin.MethodsWe undertook a retrospective study of 41 patients with early-stage ARDS (defined as one week or less after intubation) who underwent OLB in two medical intensive care units of a tertiary care hospital from 1999 to 2005. Data analyzed included baseline characteristics, complication rate, pathological diagnoses, treatment alterations, and hospital survival.ResultsThe age of patients was 55 ± 17 years (mean ± SD). The average ratio of arterial partial pressure of oxygen (PaO2) to fraction of inspired oxygen (FiO2) was 116 ± 43 mmHg (mean ± SD) at biopsy. Seventeen patients (41%) were immunocompromised. Postoperative complications occurred in 20% of patients (8/41). All biopsies provided a pathological diagnosis with a diagnostic yield of 100%. Specific pathological diagnoses were made for 44% of patients (18/41). Biopsy findings led to an alteration of treatment modality in 73% of patients (30/41). The treatment alteration rate was higher in patients with nonspecific diagnoses than in patients with specific diagnoses (p = 0.0024). Overall mortality was 50% (21/41) and was not influenced by age, gender, pre-OLB oxygenation, complication rate, pathological results, and alteration of treatment. There was no surgery-related mortality. The survival rate for immunocompromised patients was better than that for immunocompetent patients (71% versus 33%; p = 0.0187) in this study.ConclusionOur retrospective study suggests that OLB was a useful and acceptably safe diagnostic procedure in some selected patients with early-stage ARDS.

Predictors of successful weaning from prolonged mechanical ventilation in Taiwan.

BACKGROUND For adult patients on prolonged mechanical ventilation (PMV, >/=21 days), successful weaning has been attributed to various factors. The purpose of this study was to describe patient outcomes, weaning rates and factors in successful weaning at a hospital-based respiratory care center (RCC) in Taiwan. METHODS AND RESULTS This was a retrospective observational study performed in a 24-bed RCC over six years. A total of 1307 patients on PMV were included in the study. The overall survival rate was 62%. Fifty-six percent of patients were successfully weaned. Unsuccessfully weaned patients had higher MICU transfer rates, higher Acute Physiology and Chronic Health Evaluation II scores, longer duration of RCC stay, higher rates of being bed-ridden prior to admission, increased hemodialysis rates, higher modified Glasgow Coma Scale scores, higher rapid shallow breathing index, lower inspiratory pressure at residual volume (PImax) and lower blood urea nitrogen (BUN) and creatinine levels. Factors found to be associated with unsuccessful weaning were length of RCC stay (OR=1.04, P<0.001), modified GCS score (OR=0.93, P<0.046), PImax (OR=0.97, P<0.001), serum albumin concentration (OR=0.62, P<0.023) and BUN level (OR=1.01, P<0.002). CONCLUSION High rates of ventilator independence can be achieved in an RCC setting as an alternative to ICU care. Factors associated with unsuccessful weaning included longer duration of RCC stay, elevated BUN levels and lower modified GCS scores, serum albumin and PImax levels.

Acute Respiratory Distress Syndrome Caused by Leukemic Infiltration of the Lung

Respiratory distress syndrome resulting from leukemic pulmonary infiltrates is seldom diagnosed antemortem. Two 60- and 80-year-old women presented with general malaise, progressive shortness of breath, and hyperleukocytosis, which progressed to acute respiratory distress syndrome (ARDS) after admission. Acute leukemia with pulmonary infection was initially diagnosed, but subsequent examinations including open lung biopsy revealed leukemic pulmonary infiltrates without infection. In one case, the clinical condition and chest radiography improved initially after combination therapy with chemotherapy for leukemia and aggressive pulmonary support. However, new pulmonary infiltration on chest radiography and hypoxemia recurred, which was consistent with acute lysis pneumopathy. Despite aggressive treatment, both patients died due to rapidly deteriorating condition. Leukemic pulmonary involvement should be considered in acute leukemia patients with non-infectious diffusive lung infiltration, especially in acute leukemia with a high blast count.

Airborne Severe Acute Respiratory Syndrome Coronavirus Concentrations in a Negative-Pressure Isolation Room

This study used a sensitive polymerase chain reaction method coupled with filter sampling to detect the presence of airborne severe acute respiratory syndrome (SARS) coronavirus in an isolation patient room with a patient with severe acute respiratory syndrome receiving mechanical ventilatory support. Polymerase chain reaction results were negative for SARS coronavirus in room air both before and after patient extubation.

Wheezing, a significant clinical phenotype of COPD: experience from the Taiwan Obstructive Lung Disease Study.

Background COPD is an important public health challenge with significant heterogeneity of clinical presentation and disease progression. Clinicians have been trying to find phenotypes that may be linked to distinct prognoses and different therapeutic choices. Not all patients with COPD present with wheezing, a possible clinical phenotype that can help differentiate patient subgroups. Methods The Taiwan Obstructive Lung Disease study was a retrospective, multicenter research study to investigate the treatment patterns of COPD after the implementation of the Global Initiative for Chronic Obstructive Lung Disease 2011 guidelines. Between November 2012 and August 2013, medical records were retrieved from patients with COPD aged ≥40 years; patients diagnosed with asthma were excluded. Demographic data, lung function, symptom scores, and acute exacerbation were recorded and analyzed, and the differences between patients with and without wheezing were evaluated. Results Of the 1,096 patients with COPD, 424 (38.7%) had the wheezing phenotype. The wheezing group had significantly higher COPD Assessment Test scores (12.4±7.8 versus 10.5±6.7, P<0.001), higher modified Medical Research Council grade (2.0±1.0 versus 1.7±0.9, P<0.001), and more acute exacerbations within the past year (0.9±1.3 versus 0.4±0.9, P<0.001) than the nonwheezing group. The postbronchodilator forced expiratory volume in 1 second was lower in wheezing patients (1.2±0.5 L versus 1.5±0.6 L, P<0.001). Even in patients with maintenance treatment fitting the Global Initiative for Chronic Obstructive Lung Disease 2011 guidelines, the wheezing group still had worse symptom scores and more exacerbations. Conclusion Wheezing is an important phenotype in patients with COPD. Patients with COPD having the wheezing phenotype are associated with worse symptoms, more exacerbations, and worse lung function.

Renal replacement therapy in prolonged mechanical ventilation patients with renal failure in Taiwan

BACKGROUND Renal failure requiring renal replacement therapy (RRT) is associated with a high mortality rate in intensive care unit (ICU) patients. Little information is available on the outcomes of patients having prolonged mechanical ventilation (PMV) in addition to RRT. The purpose of this study was to investigate the impact of RRT in PMV patients. METHODS This was an observational, retrospective study in the 24-bed respiratory care center (RCC) of Chang Gung Memorial Hospital, Taiwan, between May 2001 and April 2007. The end points were weaning rate and survival rate at the RCC. RESULTS Of the 1301 RCC patients, 157 patients (13.7%) underwent RRT. The RRT patients had lower successful weaning rate (39.5% vs 58.4%, P < .001) and RCC survival rate (45.9% vs 71.9%, P < .001) compared with without-RRT patients. The successful weaning rates of end-stage renal disease (ESRD) patients, patients with RRT initiated at the ICU and continued at RCC, and patients whose RRT was initiated at the RCC were 49.2%, 39.1%, and 22.2%, respectively. The RCC survival rates were 50.8%, 47.8%, and 29.6%, respectively. The odds ratios of successful weaning rate and survival rate were 0.295 (95% confidence interval, 0.105-0.833; P = .021) and 0.407 (95% confidence interval, 0.155-1.021; P = .069) for patients whose RRT was initiated at the RCC vs ESRD patients. CONCLUSION The present study demonstrates that the need for RRT had a negative impact on weaning and mortality in PMV patients compared with patients without RRT. Patients who had RRT initiated at the RCC had a significantly lower weaning rate compared with ESRD patients.

Factors associated with the prescription of inhaled corticosteroids in GOLD group A and B patients with COPD – subgroup analysis of the Taiwan obstructive lung disease cohort

Background and objective The overprescription of inhaled corticosteroids (ICS) in the current Global Initiative for Chronic Obstructive Lung Disease (GOLD) group A and B patients with chronic obstructive pulmonary disease (COPD) is not uncommon in clinical practice. The aim of this study was to explore the factors associated with the use of ICS in these patients. Methods The Taiwan obstructive lung disease (TOLD) study was a retrospective, observational nationwide survey of COPD patients conducted at 12 hospitals (n=1,096) in Taiwan. Multivariate logistic regression models were used to explore the predictors of ICS prescription in GOLD group A and B patients. Results Among the group A (n=179) and group B (n=398) patients, 198 (34.3%) were prescribed ICS (30.2% in group A and 36.2% in group B, respectively). The wheezing phenotype was present in 28.5% of group A and 34.2% of group B patients. Wheezing was the most significant factor for an ICS prescription in group A (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.14–4.75; P=0.020), group B (OR, 1.93; 95% CI, 1.24–2.99; P=0.004), and overall (OR, 2.04; 95% CI, 1.40–2.96; P<0.001). The COPD assessment test score was also associated with an ICS prescription in group B (OR, 1.04; 95% CI, 1.00–1.07; P=0.038). Conclusion About one-third of the GOLD group A and B patients with COPD in Taiwan are prescribed ICS. Our findings suggest that wheezing and COPD assessment test score are related to the prescription of ICS in these patients.

A Large-Volume Nebulizer Would Not Be an Infectious Source for Severe Acute Respiratory Syndrome

We attempted to detect the presence of airborne SARS-coronavirus (CoV) in a healthcare setting when a patient with SARS used a humidifier or a large-volume nebulizer (LVN). All of the air samples from the humidifier and LVN were found to have negative SARS-CoV-specific DNA products.

Disseminated Nocardia Farcinica Presenting as Diffused Pulmonary Nodular Infiltration in a Patient with Pemphigus Vulgaris-A Case Report

Nocardia is a Gram-positive and weakly acid-fast stain-positive aerobic bacillus that is ubiquitous in the soil and water. It is an uncommon pathogen in humans, and found mostly in immunocompromised patients with variable etiologies. The acquisition of this infection is generally via the respiratory tract, and frequently involvs the subcutaneous tissue, lung, and central nervous system. There are some common predisposing factors associated with an immunocompromised status that cause nocardiosis. The image of pulmonary nocardiosis is variable and nonspecific, and the most common findings on chest radiography are: nodules/mass, cavitation, and consolidation/infiltrates. Disseminated nocardiosis with bacteremia is not common and may be fatal. We report a 57-year-old male non-smoker, who had pemphigus vulgaris and was receiving immuno-suppressive therapy, developed unexplained multiple pulmonary nodules 2 months later. Nocardia spp. bacteremia was identified, but responded poorly to trimethoprim-sulfamethoxazole (TMP/SMX) treatment. Finally, pulmonary nocardiosis was proved by open lung biopsy. Nocardia farcinica, a potentially multidrug resistant strain, was identified from positive blood culture. This is the 7(superscript th) case reported as pemphigus vulgaris complicated with human disseminated nocardiosis after therapy, from 1902 to 2005.

Pulmonary Infection with Mycobacterium Simiae-A Case Report

Mycobacterium simiae infections in humans have been reported since 1971, and are found mostly in tropical and subtropical regions. Pulmonary M. simiae infections have been presented in patients with chronic lung disease, pulmonary tuberculosis, malignancy, and acquired immunodeficiency syndrome. The optimal therapy for pulmonary M. simiae infection is not clear due to limited patient numbers. This report describes the first case of pulmonary M. simiae infection in Taiwan, found in a patient with chronic obstructive pulmonary disease who was successfully treated with clarithromycin and rifampicin. The prevalence, reservoir, clinical presentation, bacterial characteristics, diagnostic criteria, and current recommended therapy for M. simiae infection are also reviewed.