Expert panel consensus recommendations on the utilization of nebulized budesonide for managing asthma and COPD in both stable and exacerbation stages in Thailand.

OBJECTIVE: This study investigated the utilization of nebulized budesonide for acute asthma and COPD exacerbations as well as for maintenance therapy in adults. DATA SOURCES: We conducted a search on PubMed for nebulized budesonide treatment. SELECTED STUDIES: Selecting all English-language papers that utilize Mesh phrases "asthma," "COPD," "budesonide," "nebulized," "adult," "exacerbation," and "maintenance" without temporal restrictions, and narrowing down to clinical research such as RCTs, observational studies, and real-world studies. RESULTS: Analysis of 25 studies was conducted to assess the effectiveness of nebulized budesonide in asthma (n = 10) and COPD (n = 15). The panel in Thailand recommended incorporating nebulized budesonide as an additional or alternative treatment option to the standard of care and systemic corticosteroids (SCS) based on the findings. CONCLUSION: Nebulized budesonide is effective and well-tolerated in treating asthma and COPD, with less systemic adverse effects compared to systemic corticosteroids. High-dose nebulized budesonide can enhance clinical outcomes for severe and mild exacerbations with slow systemic corticosteroid response. Nebulized budesonide can substitute systemic corticosteroids in some situations.

Noninvasive ventilation in patients with acute hypoxemic respiratory failure: a systematic review and meta-analysis of randomized controlled trials.

The clinical benefits of noninvasive ventilation (NIV) for patients with acute hypoxemic respiratory failure (AHRF) is still inconclusive. We aimed to evaluate the effect of NIV compared with conventional oxygen therapy (COT)/high-flow nasal cannula (HFNC) in this patient population. We searched for relevant studies from PubMed, Embase, Cochrane Library, ClinicalTrials.gov, CINHAL, Web of Science up to August 2019 for randomized controlled trials (RCTs) that compared NIV with COT/HFNC in AHRF. The primary outcome was the tracheal intubation rate. Secondary outcomes were intensive care unit (ICU) mortality, and hospital mortality. We applied the GRADE approach to grade the strength of the evidence. Seventeen RCTs that recruited 1738 patients were included in our meta-analysis. When comparing NIV versus COT/HFNC, the pooled risk ratio (RR) for the tracheal intubation rate was 0.68, 95% confidence interval (CI) 0.52-0.89, p = 0.005, I2 = 72.4%, low certainty of evidence. There were no significant differences in ICU mortality (pooled RR = 0.87, 95% CI 0.60-1.26), p = 0.45, I2 = 64.6%) and hospital mortality (pooled RR = 0.71, 95% CI 0.51-1.00, p = 0.05, I2 = 27.4%). Subgroup analysis revealed that NIV application with helmet was significantly associated with a lower intubation rate than NIV with face mask. NIV did not show a significant reduction in intubation rate compared to HFNC. In conclusion, NIV application in patients with medical illness and AHRF was associated with a lower risk of tracheal intubation compared to COT. NIV with helmet and HFNC are promising strategies to avoid tracheal intubation in this patient population and warrant further studies. NIV application had no effect on mortality.The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42018087342).

Involvement of Transforming Growth Factor-ß-Associated Kinase 1 in Fixed Airway Obstruction in Asthmatic Patients with Longer Disease Duration Independent on Airway Eosinophilia.

Objective: Transforming growth factor-ß-associated kinase 1 (TAK1) mediates non-canonical TGF-ß signalling by promoting adhesive, migratory, proliferative and contractile responses of fibroblasts to TGF-ß1. However, TAK1 expression status in asthmatic patients with or without fixed airway obstruction (FAO) is unknown. Patients and Methods: A total of 60 adult asthmatics with FAO were recruited and compared to 43 those without FAO (nFAO). TGF-ß1 concentrations, and total TAK1 and phosphorylated TAK1 (p-TAK1) levels were determined in sputum supernatants, cytospin, and whole cell lysate by ELISA, immunocytochemistry, and Western blot analysis, respectively, in asthmatics with and without FAO. Results: Asthmatic patients with FAO had much greater sputum TGF-ß1 concentrations than those without FAO. This was independent of airway eosinophilia as there was no significant difference in TGF-ß1 levels between high and low eosinophil counts within FAO and nFAO groups. In contrast, patients with FAO in the presence of sputum eosinophilia had greater expression of TAK1 and p-TAK1 than those without sputum eosinophilia (P=0.0032 and P=0.0061, respectively). The Western Blot data of total TAK1 and p-TAK1 were consistent with the immunocytochemistry, showing upregulation in all sputum cell types (neutrophils, eosinophils, macrophages, lymphocytes and airway epithelial cells). In addition, total TAK1 expression negatively correlated with pre- and post-bronchodilator FEV1/FVC ratio. Conclusion: TAK1 may play a key role in asthmatic patients with fixed airway obstruction, which was independent of eosinophilic airway inflammation. The interruption of TAK1 might have favourable clinical impact.

Bacterial Coinfection and Superinfection in Respiratory Syncytial Virus-Associated Acute Respiratory Illness: Prevalence, Pathogens, Initial Antibiotic-Prescribing Patterns and Outcomes.

We aimed to determine the prevalence of bacterial coinfection (CoBact) and bacterial superinfection (SuperBact), the causative pathogens, the initial antibiotic-prescribing practice, and the associated clinical outcomes of hospitalized patients with respiratory syncytial virus-associated acute respiratory illness (RSV-ARI). This retrospective study included 175 adults with RSV-ARI, virologically confirmed via RT-PCR, during the period 2014-2019. Thirty (17.1%) patients had CoBact, and 18 (10.3%) had SuperBact. The independent factors associated with CoBact were invasive mechanical ventilation (OR: 12.1, 95% CI: 4.7-31.4; p < 0.001) and neutrophilia (OR: 3.3, 95% CI: 1.3-8.5; p = 0.01). The independent factors associated with SuperBact were invasive mechanical ventilation (aHR: 7.2, 95% CI: 2.4-21.1; p < 0.001) and systemic corticosteroids (aHR: 3.1, 95% CI: 1.2-8.1; p = 0.02). CoBact was associated with higher mortality compared to patients without CoBact (16.7% vs. 5.5%, p = 0.05). Similarly, SuperBact was associated with higher mortality compared to patients without SuperBact (38.9% vs. 3.8%, p < 0.001). The most common CoBact pathogen identified was Pseudomonas aeruginosa (30%), followed by Staphylococcus aureus (23.3%). The most common SuperBact pathogen identified was Acinetobacter spp. (44.4%), followed by ESBL-positive Enterobacteriaceae (33.3%). Twenty-two (100%) pathogens were potentially drug-resistant bacteria. In patients without CoBact, there was no difference in mortality between patients who received an initial antibiotic treatment of <5 days or ≥5 days.

Respiratory syncytial virus-associated acute respiratory illness in adult non-immunocompromised patients: Outcomes, determinants of outcomes, and the effect of oral ribavirin treatment.

BACKGROUND: Respiratory syncytial virus (RSV) is an increasingly common cause of respiratory illness in adult non-immunocompromised patients. Oral ribavirin was reported to improve outcomes of RSV infection in immunocompromised patients. This study aimed to determine the outcomes of non-immunocompromised patients hospitalized with RSV-associated acute respiratory illnesses (RSV-ARI), the factors independently associated with the outcomes and the effect of oral ribavirin treatment. METHODS: This retrospective, observational cohort study included 175 adults admitted to the hospital with virologically confirmed RSV-ARI during 2014-2019. Severe ARI was identified using Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) criteria for severe community-acquired pneumonia. The primary outcome was all-cause mortality within 30 days after enrollment. A multivariable Cox model was performed to identify significant predictors of mortality. RESULTS: Mean age was 76 ± 12.7 years. Seventy-eight (44.6%) patients met the diagnostic criteria for severe ARI. Thirty-six (20.6%) patients required invasive mechanical ventilation, and 11 (6.3%) required vasopressor. Ninety-nine (56.6%) patients received oral ribavirin treatment, and 52 (29.7%) received systemic corticosteroids. Forty-one (23.4%) patients had evidence of bacterial infection. Overall mortality was 7.4%. Mortality among patients with non-severe ARI and severe ARI was 1.04% and 15.4%, respectively. Estimated glomerular filtration rate <50 ml/min/1.73 m2 , severe ARI, systemic corticosteroids, and bacterial infection were independently associated with higher risk of mortality. Treatment with oral ribavirin was the only factor associated with reduced mortality (adjusted HR: 0.19, 95% CI: 0.04-0.9, P = 0.03). CONCLUSION: RSV-ARI may result in significant mortality and health care utilization. Treatment with oral ribavirin may improve survival in these patients.

Severe community-acquired pneumonia in general medical wards: outcomes and impact of initial antibiotic selection.

BACKGROUND: Most international guidelines recommend empirical therapy for community-acquired pneumonia (CAP) to be based on site of care. Some patients with severe CAP are managed in general wards because of limited intensive care unit (ICU) bed or because of unrecognition of the pneumonia severity. Appropriate initial antibiotic treatment for severe CAP outside ICU has not yet been established. This study aimed to determine the prevalence and the impact of initial antibiotic selection on the outcomes of patients with severe CAP who were admitted and managing in general wards. METHODS: This prospective observational study included consecutive patients hospitalized for presumed CAP in general wards over a 1-year period. Severe CAP was identified using the 2007 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) criteria. Initial antibiotic treatment in the first 24 h were collected. The primary outcome was the rate of unfavorable outcome (composite outcome of treatment failure and in-hospital death). The secondary outcome was the number of hospital-free days assessed 30 days after enrollment into the study. RESULTS: There were 94 patients hospitalized with CAP of which 50 (53.2%) patients were compatible with severe CAP. An etiologic diagnosis was found in 43 (45.8%) patients. The most common pathogens identified in patients with severe CAP were Staphylococcus aureus (28.6%) and Klebsiella pneumoniae (28.6%), followed by Pseudomonas aeruginosa (17.9%). Patients with severe CAP had significantly more positive blood culture than patients with non-severe CAP (24% VS 4.5%; p = .008). Initial antibiotic treatment were discordant with the IDSA/ATS guidelines in 42% of all patients hospitalized with CAP, and 52% of patients with severe CAP. Multivariate analysis revealed that age (OR 1.1, 95% CI 1.01-1.1) and initial antibiotic treatment discordant to guidelines for severe CAP in ICU (OR 4.6, 95% CI 1.3-17.1) were independent risk factors of the unfavorable outcome of patients with severe CAP. Patients with unfavorable outcome had lower number of hospital-free days than patients with favorable outcome (5.2 ± 8 days VS 18 ± 7.1 days; p < .001). CONCLUSIONS: Patients with severe CAP outside ICU should be recognized for appropriate initial antibiotic selection to improve outcomes.

Performance and applications of bedside visual inspection of airway pressure-time curve profiles for estimating stress index in patients with acute respiratory distress syndrome.

To determine the performance of bedside visual inspection of airway pressure-time (Paw-t) curve profiles (VI) for estimating stress index (SI) in patients with acute respiratory distress syndrome (ARDS). A prospective study in 30 subjects with ARDS receiving mechanical ventilation at two peak inspiratory flow (PIF) settings: 60 or 40 L/min. For each study session, two physicians inspected real-time Paw-t waveforms from mechanical ventilator's monitoring screens at bedside for 30 s and interpreted which of the three patterns (tidal recruitment, noninjurious ventilation or tidal overdistension) the Paw-t curve profile was compatible with. Subsequently, the study was repeated again at the second PIF setting. SI was derived from a standardized dedicated software program and categorized into three groups: SI < 0.9, or tidal recruitment; SI = 0.9-1.05, or noninjurious ventilation; and SI > 1.05, or tidal overdistension. The lower PIF setting increased the sensitivity of VI to correctly estimate SI (75% vs. 50%; p = 0.005). At PIF 40 L/min, the likelihood ratio of a positive test was 3.6, 5.4 or 7 if the Paw-t curve profile was interpreted as noninjurious ventilation, tidal recruitment or tidal overdistension, respectively. The likelihood ratio of a negative test ranged from 0.55 for tidal recruitment to 0.32 and 0.19 for noninjurious ventilation and tidal overdistension, respectively. Experience in mechanical ventilation did not influence the accuracy. Bedside VI is moderately accurate for estimating SI and may be used to monitor injurious ventilation in patients with ARDS, in addition to plateau airway pressure.

Clinical pulmonary infection score and a spot serum procalcitonin level to guide discontinuation of antibiotics in ventilator-associated pneumonia: a study in a single institution with high prevalence of nonfermentative gram-negative bacilli infection.

Background We wanted to determine the impact of combined Clinical Pulmonary Infection Score (CPIS) and a spot serum procalcitonin (PCT)-guided protocol to shorten the duration of antibiotic treatment in patients with ventilator-associated pneumonia (VAP), mainly caused by nonfermentative gram-negative bacilli (NF-GNB). Methods Patients with VAP who received appropriate antibiotics for 7 days, temperature ⩽ 37.8°C, without shock, and CPIS ⩽ 6 were allocated to the PCT group or conventional group according to the treating physicians' decisions. In the PCT group, antibiotics were stopped if the PCT level on day 8 < 0.5 ng/ml. In the conventional group, antibiotics were stopped according to physicians' discretion. Results There were 24 patients in the PCT group and 26 patients in the conventional group. NF-GNB were responsible for VAP in 79.2% of the PCT group and 65.4% of the conventional group. PCT group had a greater number of antibiotic-free days alive during the 28 days after VAP onset than the conventional group (14.6 ± 5.4 days versus 5.9 ± 5.7 days, respectively; p <.001). In the multivariate, propensity score-adjusted analysis, the PCT group [coefficient = -9.1 (-12.2 to -6); p <.001] and extrapulmonary infections [coefficient = 6.4 (3.3-9.5); p <.001] were independent predictors of total antibiotic exposure days. There was no relapse in both groups. Meanwhile, 12.5% of the PCT group and 26.9% of the conventional group subsequently developed recurrent VAP compatible with superinfections. Conclusions CPIS and a spot serum PCT level appeared effective and safe to guide discontinuation of antibiotic treatment in patients with VAP caused by NF-GNB. TRIAL REGISTRATION: TCTR20160726002.

Mechanical Ventilation of Patients Hospitalized on General Medical Ward: Outcomes and Prognostic Factors.

Background: In some hospitals, patients hospitalized on the medical ward are mechanically ventilated due to a shortage of intensive care unit (ICU) beds.. Objective: To determine outcomes and prognostic factors of medical patients mechanically ventilated on general medical wards. Material and Method: A prospective observational study was performed in general medical wards of a 2,000-bed tertiary care university hospital. Results: Ninety-three consecutive medical patients who were mechanically ventilated on a general medical ward were included in the study. Overall mortality rate of patients mechanically ventilated on the general medical ward was 68.8%. Average length of stay was 22.9±28.5 days. Average cost per patient was 61,076.64±87,569.10 Thai baht. In univariate analysis, the APACHE II score of the patients who did not survive was significantly higher than the score of the patients who survived (mean APACHE II score 23.3±7.3 vs. 19.8±5.5 respectively, p = 0.02). Multivariate analysis revealed APACHE II score >22 to be the only independent predictor of death (OR 4.3, 95% CI 1.2-15.2, p = 0.02). Conclusion: Medical patients who are mechanically ventilated on general medical wards have high mortality rate. APACHE II score is a good prognostic factor for predicting risk of death in these patients

Induction of cross-neutralizing antibody against H5N1 virus after vaccination with seasonal influenza vaccine in COPD patients.

Archival serum samples from elderly individuals with underlying chronic obstructive pulmonary disease (COPD) who were enrolled in a double-blind case-control study of seasonal influenza vaccine efficacy were assayed for cross-neutralizing antibody formation to avian influenza A (H5N1) virus. Of 118 serum samples, 58 were collected from influenza vaccinees (mean age 68.5 y), and 60 from placebo controls (mean age 68.4 y) who received vitamin B injections. Blood samples were collected before and at 1 mo after seasonal influenza vaccination from all subjects; in addition, for a longitudinal follow-up period of 1 y paired-blood samples were collected again from subjects who developed acute respiratory illness. Hemagglutination inhibition assay for antibodies to influenza A (H1N1), influenza A (H3N2), and influenza B viruses was carried out to determine the serological response to vaccination, and to diagnose influenza viral infection, while microneutralization assays were performed to detect cross-reactive antibody to H5N1 virus. Pre-existing cross-reactive H5N1 antibody at reciprocal titer 10 was found in 6 (10.3%) vaccinees and 4 (6.7%) placebo controls. There was no change in H5N1 antibody titer in these subjects after vaccination. On the other hand, 3 (5.2%) vaccinees developed seroconversion to H5N1 virus at 1 mo after vaccination, even though they had no pre-existing H5N1 antibody in their first blood samples. No cross-neutralizing antibody to H5N1 virus was detected in the placebo controls or in the 22 influenza patients, suggesting that influenza vaccination, but not influenza virus infection, induces cross-neutralizing antibody against avian influenza H5N1 virus.

The immunogenicity of intradermal influenza vaccination in COPD patients.

We evaluated the immunogenicity of a reduced-dose intradermal trivalent, inactivated, split-virion seasonal influenza vaccine compared to that of a conventional intramuscular vaccination in chronic obstructive pulmonary disease (COPD) patients. One hundred and fifty-six COPD patients randomly received either 0.2 ml (6 microg hemagglutinin (HA) per strain) split into two-site intradermal (ID) injections or a single 0.5 ml (15 microg HA per strain) intramuscular (IM) injection. Geometric mean titers, seroconversion factors, seroconversion rates and seroprotection rates at 4 weeks post-vaccination in the ID group were less than those in the IM group. Only the seroconversion factor to influenza B in the ID group was statistically less than in the IM group (18.8 in the ID group, n=81 versus 37.3 in the IM group, n=75, p=0.045). Nevertheless, each strain of the ID vaccination met all the Committee for Proprietary Medicinal Products (CPMP) criteria. Seroprotection rates were above 60% throughout the year in influenza A (H3N2), for at least 6 months in influenza A (H1N1) and at least 4 weeks in influenza B in both ID and IM groups. The reduced-dose intradermal vaccination may be considered for use in COPD patients in a vaccine shortage situation.

Development of appropriate procedures for inflation of endotracheal tube cuff in intubated patients.

BACKGROUND: Hyperinflation of endotracheal tube cuff causes tracheal mucosal damage and underinflation increases the risk of pneumonia. The current practice on inflation of endotracheal tube cuff in the intubated patients hospitalized at Siriraj Hospital uses the estimation method. The authors determined appropriateness of such current practice and developed an appropriate procedure for inflation of endotracheal tube cuff in intubated patients. MATERIAL AND METHOD: The endotracheal tube cuff pressures of 34 intubated patients in Siriraj Hospital were measured by manometer once daily. Inflation of the endotracheal tube cuffs of 20 patients was done and the volume of air required to optimize the intracuff pressure of 25 cmH2O was recorded. The intracuff pressure was measured every one hour for eight consecutive hours in the patients who had initial intracuff pressure of 25 cmH2O and 30 cmH2O. The nurses in the experimental wards used a manometer as a guide to inflate endotracheal tube cuff until the intracuff pressure was 30 cmH2O every eight hours, whereas the control wards used conventional procedures to inflate the endotracheal tube cuff. The endotracheal tube cuff pressures of the patients in both groups were measured twice daily. RESULTS: Only 34% of intracuff pressure measurements were 20-30 cmH2O. The mean volume of inflated air required to achieve an intracuff pressure of 25 cmH2O was 7.1 ml. An initial intracuff pressure of 30 cmH2O decreased to 20 cmH2O at 7 to 9 hours after inflation. The rate of optimum endotracheal tube cuff pressure was 90.5% in the group guided by manometer and 31.8% in the conventional procedure group (p < 0.001, RR 2.85, 95% CI 2.44-3.32). CONCLUSION: Inflation of endotracheal tube cuff should be guided by manometer to achieve a pressure of 30 cmH2O every eight hours.

Adverse effects associated with influenza vaccination in patients with COPD: a randomized controlled study.

OBJECTIVE: The aim of this study was to assess the frequency and type of adverse reactions following influenza vaccination and its effects on lung function, dyspnoeic symptoms, exercise capacity, and clinical acute respiratory illness (ARI) in patients with COPD, and the relationship of these adverse effects to the degree of airflow obstruction. METHODOLOGY: A stratified, randomized, double-blind placebo-controlled study was conducted over an 18-month period at a single university hospital. In total, 125 patients with COPD were randomized to the vaccine group (62 patients who received purified trivalent split-virus vaccine injections) or the placebo group (63 patients). Local and systemic symptoms during the week following the injections were evaluated. Clinical ARI, lung function tests, dyspnoeic symptoms (assessed using a visual analogue scale), and a 6-min walking test were evaluated before and at 1 week and 4 weeks following vaccination. RESULTS: The frequency of local adverse reactions was 27% in the vaccine group and 6% in the placebo group (P = 0.002). There was no significant difference in systemic adverse reactions between the vaccine and placebo groups (76% vs. 81%; P= 0.5). No difference was observed in the incidence of ARI between the vaccine and placebo groups during the first week (6.4% vs. 6.3%; P= 1) and the first 4 weeks (24.2% vs. 31.7%; P= 0.5) following vaccination. There was no significant change in lung function, dyspnoeic symptoms, and exercise capacity of the patients in both groups, at 1 week and 4 weeks following vaccination, regardless of the severity of COPD. CONCLUSION: Influenza vaccination is associated with minimal local adverse reactions in patients with COPD. Vaccination does not cause systemic adverse reactions, induce clinical exacerbations or adversely affect lung function, dyspnoeic symptoms and exercise capacity in patients with COPD, regardless of the severity of airflow obstruction.

Occurrence and protective level of influenza infections using serology in patients with COPD in vaccination study.

OBJECTIVE: To investigate the prevalence, occurrence and protective level of influenza infections using serology in patients with chronic obstructive pulmonary disease (COPD) during a one-year influenza vaccination study. MATERIAL AND METHOD: A total of 123 patients with COPD were enrolled during the period of 1997 to 1998. There were 61 patients in the vaccine group and 62 patients in the placebo group with a mean age +/- SD of 67.6 +/- 8.0 and 69.1 +/- 7.5, respectively. The vaccine was composed of influenza A/Texas/36/91 (H1N1), A/Nanchang/933/95 (H3N2) and B/Harbin/07/94 strains. Antibodies to influenza viruses were detected by hemagglutination inhibition (HI) test using antigens of vaccine strains. RESULTS: The incidence of influenza proven by serological examination was 22/123 (17.9%) cases. Among 17/62 (27.4%) influenza cases in the placebo group representing natural infections, 3 (17.6%) were diagnosed as A (H1N1), 8 (47.1%) as A (H3N2), 3 (17.6%) as type A, 1 (5.9%) as type B and 2 (11.8%) as untypeable viruses. The 8.2% of influenza cases found in the vaccine group was significantly lower than 27.4% of that in the placebo group (Chi-square test, p = 0.01). The protection rate of influenza vaccination was 71%. Among 23 acute blood samples from 22 influenza cases, the titers ranged from < 10 to 20 corresponding to its type/subtype. In the vaccine group, 5 influenza cases occurred at 7, 7, 10, 11 and 11 months after vaccination. The HI antibodies to influenza A (H1N1), A (H3N2) and B viruses at titers of > or = 10 vs > or = 40 were 50.4% vs 21.9%, 54.5% vs 28.5% and 17.9% vs 4.1%, respectively. CONCLUSION: The findings indicated that from 1997 to 1998, the occurrence of influenza as natural infection was 27.4%. Influenza A (H3N2) was more frequently prevalent than A (H1N1) and B viruses. The influenza vaccination in COPD patients was effective. The protective HI antibody titers were > or = 40. The patients without protective HI antibody to A (H1N1), A (H3N2) and B viruses were 78.1%, 71.5% and 95.9%, respectively. Such patients were considered to be at high-risk for influenza and recommended to have vaccination.

Changing pattern of ventilator settings in patients without acute lung injury: changes over 11 years in a single institution.

STUDY OBJECTIVES: To determine whether the widely accepted concept of using lower tidal volume (Vt) values in patients with ARDS or obstructive lung disease has affected the pattern of ventilator settings in mechanically ventilated patients who do not have one of these conditions. DESIGN AND PATIENTS: We performed a retrospective chart review of all patients who had experienced out-of-hospital cardiac arrest and had received ventilatory support for > or = 1 day at a university-affiliated county hospital during the years 1990, 1991, 1992, 1995, 1998, 1999, and 2000. RESULTS: In 139 such patients, the mean final Vt values used on the first day of mechanical ventilation were 11.7, 12.4, 11.3, 9.6, 9.7, 9.2, and 9.8 mL/kg in those years, respectively. Multivariate analysis revealed that increasing year (beta-coefficient = -0.24; p = 0.001) and the presence of pulmonary edema (beta-coefficient = -1.2; p = 0.001) were independent predictors of the use of lower Vt values. Patients managed with a low Vt (ie, < 10 mL/kg; mean [+/- SD] Vt, 8.4 +/- 1.3 mL/kg) had a significantly higher incidence of atelectasis than the patients who were managed with traditional, larger Vt values (ie, > or = 10 mL/kg; mean Vt, 11.8 +/- 1.5 mL/kg) [61.1% vs 36.7%, respectively; p = 0.02]. Multivariate analysis revealed that the mean Vt used on days 1, 2, and 3 (<10 mL/kg or > or = 10 mL/kg) was the only predictor of the development of atelectasis during the first 3 days of mechanical ventilation (odds ratio, 0.33; p = 0.015). There was no difference in the incidence of pneumonia, the number of days spent receiving mechanical ventilation, Pao(2)/fraction of inspired oxygen ratio, or respiratory system compliance between the low Vt group and the traditional Vt group. CONCLUSION: Currently, physicians at our hospital use lower Vt values than they have in the past. This is associated with the increase in the incidence of atelectasis in the patients who received ventilation using low Vt values.

Prevalence and incidence of Chlamydia pneumoniae antibodies among the healthy elderly and patients with chronic obstructive pulmonary diseases.

Chlamydia pneumoniae is an obligatory intracellular bacteria which can cause both acute and chronic respiratory tract infection. The significance of chronic and recurrent respiratory infection may be of prime importance in chronic obstructive pulmonary diseases (COPD). The purpose of this study was to determine the prevalence and incidence of C. pneumoniae antibodies in elderly COPD patients compared to a healthy elderly control group. C. pneumoniae antibodies were detected by an enzyme-linked immunosorbent assay in serum samples obtained from 127 elderly COPD patients and a 131 healthy elderly control group. The results showed that the seroprevalence of C. pneumoniae infection as determined by the existence of specific IgG or IgA or IgM antibodies was 96.1% in the COPD patients and 75.6% in the control group (p < 0.01). The prevalence of individual C. pneumoniae IgG, IgA and IgM in elderly COPD vs healthy control was 85.8% vs 66.4%, 85.0% vs 51.1% and 3.9% vs 0%, respectively. The incidence or seroconversion rate of C. pneumoniae antibodies after one year follow-up was found to be 33% in the COPD patients and 67.9% in the control group. High prevalence and incidence of C. pneumoniae antibodies indicates that both acute and chronic C. pneumoniae infection play a role in elderly COPD patients. Therefore, antibiotics of choice for C. pneumoniae infection should probably be considered.

Acute respiratory illness in patients with COPD and the effectiveness of influenza vaccination: a randomized controlled study.

STUDY OBJECTIVES: To determine the effectiveness of influenza vaccination on influenza-related acute respiratory illness (ARI) and overall ARI in patients with COPD, and its relationship to the degree of airflow obstruction. DESIGN: Stratified, randomized, double-blind, placebo-controlled trial. SETTING: From June 1997 to November 1998 at a single university hospital. PATIENTS AND INTERVENTIONS: One hundred twenty-five patients with COPD were stratified based on their FEV(1) as having mild, moderate, and severe COPD. Within each group, they were randomized to the vaccine group (62 patients who received purified, trivalent, split-virus vaccine) or the placebo group (63 patients). MEASUREMENTS: The number of episodes and severity of total ARI, classified as outpatient treatment, hospitalization, and requirement of mechanical ventilation; and the number of episodes and severity of influenza-related ARI. RESULTS: The incidence of influenza-related ARI was 28.1 per 100 person-years and 6.8 per 100 person-years in the placebo group and vaccine group, respectively (relative risk [RR], 0.24 [p = 0.005]; vaccine effectiveness, 76%). The incidences were 28.2, 23.8, and 31.2 per 100 person-years in the patients with mild, moderate, and severe COPD, respectively, in the placebo group, and 4.5, 13.2, and 4.6 per 100 person-years in the patients with mild, moderate, and severe COPD, respectively, in the vaccine group (RR, 0.16 [p = 0.06]; vaccine effectiveness, 84%; RR, 0.55 [p = 0.5]; vaccine effectiveness, 45%; and RR, 0.15 [p = 0.04]; vaccine effectiveness, 85%, in the patients with mild, moderate, and severe COPD, respectively). Bivariate analysis revealed that the effectiveness of influenza vaccination was not modified by the severity of COPD, comorbid diseases, age, gender, or current smoking status. There was no difference in the incidence or severity of total ARI between the placebo group and the vaccine group. CONCLUSIONS: Influenza vaccination is highly effective in the prevention of influenza-related ARI regardless of the severity of COPD. Influenza vaccination does not prevent other ARIs unrelated to influenza. The effectiveness of influenza vaccination in the prevention of overall ARI in patients with COPD will depend on how much the proportion of influenza-related ARI contributes to the incidence of total ARI. Influenza vaccination should be recommended to all patients with COPD.

Economic evaluation of influenza vaccination in Thai chronic obstructive pulmonary disease patients.

UNLABELLED: To determine the cost-effectiveness and cost-benefit of influenza vaccination in chronic obstructive pulmonary disease (COPD) patients the authors conducted a stratified randomized, double-blind, placebo-controlled trial from June 1997 to November 1998 at a university hospital in Thailand. A total of 125 COPD patients were stratified based on their FEV1 as mild COPD (FEV1 > or = 70% predicted), moderate COPD (FEV1 50-69% predicted) and severe COPD (FEV1 < 50% predicted) and in each severity stratum they were randomized to the vaccine group (received intramuscular injection with purified trivalent split-virus vaccine containing A/Texas/36/91 (H1N1), A/Nanchang 1933/95 (H3N2) and B/Harbin 107/94) or the placebo group (received intramuscular injection with vit B1). Number of episodes of acute respiratory illness (ARI) related to influenza (clinical ARI + a serum hemagglutination inhibition antibody titre of 38 or greater and a four fold titre increase in convalescent serum compared to acute serum) as well as severity of each ARI (outpatient treatment, hospitalization or required mechanical ventilation) and costs of treatment (direct medical costs comprised real drug costs from the hospital dispensary in outpatient cases and real charges in hospitalization cases) were collected and analyzed for the cost-effectiveness and cost-benefit of influenza vaccination. The incidence of influenza-related ARI in the study year was 27 per cent in the placebo group and 6.4 per cent in the vaccine group (relative risk [RR] 0.24, vaccine effectiveness 76%). The incidence was 27.3 per cent, 23.5 per cent and 29.2 per cent in mild, moderate and severe COPD respectively in the placebo group and 4.3 per cent, 12.5 per cent, and 4.3 per cent in the mild, moderate and severe COPD respectively in the vaccine group (RR 0.16, 0.53 and 0.15; vaccine effectiveness 84%, 47%, and 85% respectively). The incremental cost-effectiveness ratios demonstrated that for every 100 patients with mild COPD whom the authors decided to vaccinate, the cost would be 24,840 baht more and would prevent 18.2 outpatients, 4.8 hospitalizations and 0 patient from mechanical ventilation due to ARI related to influenza. Likewise, the authors would have prevented 5.1 outpatients, 5.9 hospitalizations, 5.9 mechanical ventilation and 20.8 outpatients, 3.9 hospitalizations, 8.3 mechanical ventilation for every 100 moderate COPD and every 100 severe COPD patients vaccinated respectively. More than 90 per cent of the costs of treatment of influenza-related ARI were costs of hospitalization and for patients with moderate and severe airflow obstruction, more than 90 per cent of these costs were attributed to the costs of treating the patients who required mechanical ventilation. Predicted cost savings for every 100 mild COPD, 100 moderate COPD and 100 severe COPD patients vaccinated were 125,629 baht, 538,184.3 baht, and 680,647.1 baht respectively. IN CONCLUSION: Influenza vaccination is highly effective in the prevention of acute respiratory illness related to influenza virus infection in COPD, regardless of severity of airflow obstruction. Vaccination is more cost-effective in preventing mechanical ventilation episodes and more cost-benefit in patients with more severe airflow obstruction. Influenza vaccination should be recommended to all patients with COPD with the higher priority provided to patients with more severe airflow obstruction.

Comparison between specified percentage and fifth percentile criteria for spirometry interpretation in Thai patients.

OBJECTIVES: The present study was conducted to determine the degree of agreement between the interpretation of spirometry using a specified percentage of predicted value (SPC) and the fifth percentile (FPC) as the cut off between normal and abnormal. METHODOLOGY: Spirometric values were collected for 1754 subjects attending the respiratory service at Siriraj Hospital between February 2000 and April 2001. These values included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, maximal mid-expiratory flow (FEF25-75%) and peak expiratory flow (PEF). A comparison of results between SPC and FPC was performed. The SPC cut-off values for FVC, FEV1, FEV1/FVC, FEF25-75% and PEF were 80% predicted, 80% predicted, 70%, 65% predicted and 80% predicted, respectively. The FPC cut-off values were calculated from reference equations for the Thai population. Inter-rater agreement was calculated as the kappa score. RESULTS: High kappa scores were obtained for FVC (0.84), FEV1 (0.88) and FEF25-75% (0.80). However, poor agreement was found for FEV1/FVC (0.72) and PEF (0.61). When the cut-off values for SPC were modified to 90% of predicted values for FEV1/FVC and to 65% of predicted values for PEF, agreement was substantially improved to 0.92 and 0.89, respectively. CONCLUSIONS: Interpretation by SPC using cut-off values of 80% predicted for FVC and FEV1 and 65% predicted for FEF25-75% resulted in good agreement with FPC. However, the SPC cut-off values for FEV1/FVC and PEF should be modified to 90% predicted and 65% predicted, respectively.