Chalerm Liwsrisakun

Ventilator-Associated Pneumonia: Epidemiology and Prognostic Indicators of 30-Day Mortality

We conducted a retrospective cohort study in the medical intensive care unit of Chaing Mai University Hospital to describe the epidemiology of ventilator-associated pneumonia (VAP) and identify prognostic indicators of 30-day VAP mortality. A total of 621 patients diagnosed with VAP between January 2005 and December 2011 were included. The overall 30-day mortality rate was 44.4%. The major causative pathogens were Acinetobacter baumannii (54.3%), Pseudomonas aeruginosa (35.2%), and methicillin-resistant Staphylococcus aureus (15.1%). Most A. baumannii (90.2%) comprised drug-resistant strains. Identified prognostic indicators were co-morbid malignancy (hazard ratio [HR] = 1.60; 95% confidence interval [CI] 1.02-2.42; P = 0.040), septic shock (HR = 2.51; 95% CI, 1.60-4.00; P < 0.001), Simplified Acute Physiology Score II >45 (HR = 1.62; 95% CI, 1.03-2.56; P = 0.041), Sequential Organ Failure Assessment score >5 (HR = 3.40; 95% CI 2.00-5.81; P < 0.001), and delayed inappropriate empirical antibiotic treatment (HR = 2.23; 95% CI, 1.12-4.45; P = 0.022). VAP was associated with high mortality. The major causative pathogen was drug-resistant A. baumannii. Therefore, early detection of VAP by surveillance in mechanically ventilated patients leading to earlier treatment may improve patient outcomes. Guidelines for prescribing appropriate empirical antibiotics to cover drug-resistant bacteria could be established using local epidemiological data.

Acute effects of air pollution on peak expiratory flow rates and symptoms among asthmatic patients in Chiang Mai, Thailand

The open burnings and forest fires have been recognized as the major sources of severe air pollution in the upper north of Thailand; however, there have been no clear evidences to show the associations between the air pollution and health effects in the area. We assessed the effects of air pollutants on the peak expiratory flow rates (PEFR) and symptoms in asthmatics. A cohort of 121 asthmatics was followed daily, for 306 days, for their PEFR and asthma symptoms. The daily air pollutants, including particulate matter with aerodynamic diameter <2.5 μm, particulate matter with aerodynamic diameter <10 μm (PM(10)), carbon monoxide, ozone, nitrogen dioxide (NO(2)), and sulfur dioxide (SO(2)), and the meteorological parameters, including pressure, temperature, relative humidity, rain quantity, and sunshine duration, were monitored. The PEFRs were fitted with general linear mixed models. The asthma symptoms were analyzed with the generalized estimating equations. There were positive associations of NO(2) with morning PEFR, with a coefficient of 0.06 [95% confidence interval (CI), 0.00-0.12]; of SO(2) with evening PEFR [with a range of coefficients of 0.88-1.00 (95% CI, 0.31-1.54)] and daily average PEFR [with a coefficient of 0.47 (95% CI, 0.00-0.94)]; of PM(10) with evening PEFR, with a coefficient of 0.02 (95% CI, 0.00-0.04). There was also negative association of PM(10) with ΔPEFR, with a coefficient of -0.01 (95% CI, -0.01 to -0.00). No pollutants were related to asthma symptoms. More studies are needed, particularly at low dose in adult asthmatics, to validate our findings.

Long-term efficacy of intensive cycle ergometer exercise training program for advanced COPD patients.

Background Exercise training has been incorporated into the international guidelines for the treatment of chronic obstructive pulmonary disease (COPD). However, the long-term efficacy of the training program for patients with advanced COPD has never been evaluated in Thailand. Purpose To determine the long-term efficacy of intensive cycle ergometer exercise program on various clinical parameters of patients with advanced COPD. Materials and methods The patients with advanced COPD were separated into two groups: the intensive ergometer exercise program group and the control group. The clinical parameters of all the patients were assessed at baseline, every month for the first 3 months, and then every 3 months until they had completed the 24-month follow-up. Mann–Whitney U test was used to compare baseline mean differences between the groups. Repeated measure analysis was applied to determine the progress in all parameters during the entire follow-up period. Mean incase imputation method was applied to estimate the parameters of dropout cases. Results A total of 41 patients were enrolled: 27 in the intensive ergometer exercise program group and 14 in the control group. The intensive cycle ergometer exercise program group showed statistically significant improvements in muscle strength (from month 1 till the end of the study, month 24), endurance time (from month 1 till the end of measurement, month 12) and clinically significant improvements in 6-minute walk distance (from month 2 until month 9), dyspnea severity by transitional dyspnea index (from month 1 till the end of the study, month 24), and quality of life (from month 1 till the end of the study, month 24). There was no significant difference in survival rates between the groups. Conclusion The intensive ergometer exercise training program revealed meaningful long-term improvements in various clinical parameters for up to 2 years. These promising results should encourage health care professionals to promote exercise training for patients with advanced COPD who have limited daily activities despite optimal medication control.

Detection of acute deterioration in health status visit among COPD patients by monitoring COPD assessment test score

Background The Chronic Obstructive Pulmonary Disease Assessment Test (CAT) could play a role in detecting acute deterioration in health status during monitoring visits in routine clinical practice. Objective To evaluate the discriminative property of a change in CAT score from a stable baseline visit for detecting acute deterioration in health status visits of chronic obstructive pulmonary disease (COPD) patients. Methods The CAT questionnaire was administered to stable COPD patients routinely attending the chest clinic of Chiang Mai University Hospital who were monitored using the CAT score every 1–3 months for 15 months. Acute deterioration in health status was defined as worsening or exacerbation. CAT scores at baseline, and subsequent visits with acute deterioration in health status were analyzed using the t-test. The receiver operating characteristic curve was performed to evaluate the discriminative property of change in CAT score for detecting acute deterioration during a health status visit. Results A total of 354 follow-up visits were made by 140 patients, aged 71.1±8.4 years, with a forced expiratory volume in 1 second of 47.49%±18.2% predicted, who were monitored for 15 months. The mean CAT score change between stable baseline visits, by patients’ and physicians’ global assessments, were 0.05 (95% confidence interval [CI], −0.37–0.46) and 0.18 (95% CI, −0.23–0.60), respectively. At worsening visits, as assessed by patients, there was significant increase in CAT score (6.07; 95% CI, 4.95–7.19). There were also significant increases in CAT scores at visits with mild and moderate exacerbation (5.51 [95% CI, 4.39–6.63] and 8.84 [95% CI, 6.29–11.39], respectively), as assessed by physicians. The area under the receiver operating characteristic curve of CAT score change for the detection of acute deterioration in health status was 0.89 (95% CI, 0.84–0.94), and the optimum cut-off point score was at 4, with a sensitivity, specificity, and accuracy of 76.8%, 83.6%, and 82.4%, respectively. Conclusions Change in CAT score during monitoring visits is useful for detecting acute deterioration in health status, and a change of 4 units could make a moderate prediction of acute deterioration in health status.

Prognostic factors associated with mortality of drug-resistant Acinetobacter baumannii ventilator-associated pneumonia.

BackgroundVentilator-associated pneumonia (VAP) caused by drug-resistant Acinetobacter baumannii is associated with high mortality in critically ill patients. We identified the prognostic factors of 30-day mortality in patients with VAP caused by drug-resistant A. baumannii and compared survival outcomes among multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) A. baumannii VAP.MethodsA retrospective cohort study was conducted in the Medical Intensive Care Unit at Chiang Mai University Hospital, Thailand. All adult patients diagnosed with A. baumannii VAP between 2005 and 2011 were eligible. Univariable and multivariable Cox’s proportional hazards regression were performed to identify the prognostic factors of 30-day mortality.ResultsA total of 337 patients with microbiologically confirmed A. baumannii VAP were included. The proportion of drug-sensitive (DS), MDR, XDR, and PDR A. baumannii were 9.8%, 21.4%, 65.3%, and 3.6%, respectively. The 30-day mortality rates were 21.2%, 31.9%, 56.8%, and 66.7%, respectively. The independent prognostic factors were SOFA score >5 (hazard ratio (HR) = 3.33, 95% confidence interval (CI) 1.94–5.72, P < 0.001), presence of septic shock (HR = 2.66, 95% CI 1.71–4.12, P < 0.001), Simplified Acute Physiology Score (SAPS) II >45 (HR = 1.58, 95% CI 1.01–2.46, P = 0.045), and inappropriate initial antibiotic treatment (HR = 1.53, 95% CI 1.08–2.20, P = 0.016).ConclusionsDrug-resistant A. baumannii, particularly XDR and PDR, was associated with a high mortality rate. Septic shock, high SAPS II, high SOFA score, and inappropriate initial antibiotic treatment were independent prognostic factors for 30-day mortality.

Peak expiratory flow rate as a surrogate for forced expiratory volume in 1 second in COPD severity classification in Thailand.

Background There are limited studies directly comparing correlation and agreement between peak expiratory flow rate (PEFR) and forced expiratory volume in 1 second (FEV1) for severity classification of COPD. However, clarifying the role of PEFR as a surrogate of COPD severity classification instead of FEV1 is essential in situations and areas where spirometry is not routinely available. Purpose To evaluate the agreement between FEV1 and PEFR using Global initiative for chronic Obstructive Lung Disease (GOLD) severity classification criteria. Materials and methods This cross-sectional study included stable COPD patients. Both absolute values and % predicted FEV1 and % predicted PEFR were obtained from the same patients at a single visit. The severity of COPD was classified according to GOLD criteria. Pearson’s correlation coefficient was used to examine the relationship between FEV1 and PEFR. The agreement of % predicted FEV1 and % predicted PEFR in assigning severity categories was calculated using Kappa statistic, and identification of the limits of agreement was by Bland–Altman analysis. Statistical significance was set at P-value <0.05. Results Three hundred stable COPD patients were enrolled; 195 (65.0%) male, mean age 70.4±9.4 years, and mean % predicted FEV1 51.4±20.1. Both correlations between the % predicted FEV1 and PEFR as well as the absolute values were strongly significant (r=0.76, P<0.001 and r=0.87, P<0.001, respectively). However, severity categories of airflow limitation based on % predicted FEV1 or PEFR intervals were concordant in only 179 patients (59.7%). The Kappa statistic for agreement was 0.41 (95% confidence interval, 0.34–0.48), suggesting unsatisfied agreement. The calculated limits of agreement were wide (+27.1% to −28.9%). Conclusion Although the correlation between FEV1 and PEFR measurements were strongly significant, the agreement between the two tests was unsatisfied and may influence inappropriate clinical decision making in diagnosis, severity classification, and management of COPD.

Comparative study on health care utilization and hospital outcomes of severe acute exacerbation of chronic obstructive pulmonary disease managed by pulmonologists vs internists.

Background Care for many chronic health conditions is delivered by both specialists and generalists. Differences in patients’ quality of care and management between generalists and specialists have been well documented for asthma, whereas a few studies for COPD reported no differences. Objective The objective of this study is to compare consistency with Global initiative for chronic Obstructive Lung Disease guidelines, as well as rate, health care utilization, and hospital outcomes of severe acute exacerbation (AE) of COPD patients managed by pulmonologists and internists. Materials and methods This is a 12-month prospective, comparative observational study among 208 COPD patients who were regularly managed by pulmonologists (Group A) and internists (Group B). Clinical data, health care utilization, and hospital outcomes of the two groups were statistically compared. Results Out of 208 enrolled patients, 137 (Group A) and 71 (Group B) were managed by pulmonologists and internists, respectively. Pharmacological treatment corresponding to disease severity stages between the two groups was not statistically different. Group A received care consistent with guidelines in terms of annual influenza vaccination (31.4% vs 9.9%, P<0.001) and pulmonary rehabilitation (24.1% vs 0%, P<0.001) greater than Group B. Group A had reduced rates (12.4% vs 23.9%, P=0.033) and numbers of severe AE (0.20±0.63 person-years vs 0.41±0.80 person-years, P=0.029). Among patients with severe AE requiring mechanical ventilation, Group A had reduced mechanical ventilator duration (1.5 [1–7] days vs 5 [3–29] days, P=0.005), hospital length of stay (3.5 [1–20] days vs 16 [6–29] days, P=0.012), and total hospital cost (

Misidentification of airflow obstruction: prevalence and clinical significance in an epidemiological study

863 [247–2,496] vs

Effects of seasonal smog on asthma and COPD exacerbations requiring emergency visits in Chiang Mai, Thailand.

2,095 [763–6,792], P=0.049) as compared with Group B. Conclusion This study demonstrated that pulmonologists followed national COPD guidelines more closely than internists. The rates and frequencies of severe AE were significantly lower in patients managed by pulmonologists, and length of hospital stay and cost were significantly lower among the patients with severe AE who required mechanical ventilation.

Dialectal influence on chronic pulmonary disease assessment test: the reliability and validity study

Background The fixed threshold criterion for the ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) <0.7 is widely applied for diagnosis of airflow obstruction (AO). However, this fixed threshold criterion may misidentify AO, because thresholds below the fifth percentile of normal FEV1/FVC (lower limit of normal; LLN) vary with age. This study aims to identify the prevalence of AO misidentification and its clinical significance. Materials and methods A cross-sectional population-based study was conducted to identify the prevalence of chronic respiratory diseases in adults older than 40 years of age who live in municipal areas of Chiang Mai province, Thailand. All randomly selected subjects underwent face-to-face interviews and examinations by pulmonologists, and received chest radiographs and post-bronchodilator spirometry. AO misidentification was classified into under- or overestimated AO subgroups. Underestimated AO was defined as ratio of FEV1/FVC greater than the fixed threshold, but below the LLN criteria. Overestimated AO was defined as the ratio of FEV1/FVC below the fixed threshold but greater than the LLN criteria. The clinical significance of each misidentified subject was then explored. Results There were 554 subjects with a mean age of 52.9±10.1 years and a percent predicted FEV1 of 85.5%±15.4%. The prevalence of AO misidentification was 5.6% (31/554), and all subjects belonged to the underestimated subgroup. Clinical significance of underestimated subjects included clinical AO disease of 22.6% (7/31) (three subjects with chronic obstructive pulmonary disease [COPD] and four subjects with asthma); chronic respiratory symptoms of 54.8% (17/31) (mostly associated with chronic rhinitis, 70.6% [12/17]); and only 12.9% (4/31) were identified as non-ill subjects. Conclusion The prevalence of AO misidentification in this population was significant, and all were underestimated subjects. Most underestimated subjects had clinical significance as related to obstructive airway diseases and chronic respiratory symptoms, mostly associated with rhinitis.