INTRODUCTION: Respiratory failure is common in immunocompromised patients. Intubation and mechanical ventilation (MV) is the mainstay of treatment but is associated with increased risk of pneumonia and other complications. Non-invasive ventilation (NIV) is an alternative to MV in a select group of patients and aims to avoid the complications of MV. In these patients, we performed a meta-analysis on the effect of NIV versus conventional oxygen therapy in reducing intubation rates and other important clinical outcomes.

METHODS: We performed an extensive online and unpublished data search for relevant studies that met the inclusion criteria. Randomized controlled trials that used NIV versus conventional oxygen therapy in immunocompromised patients with respiratory failure were included in the metaanalysis. Eligbility and risk of bias assessments were performed independently by three authors. The primary outcome of interest was intubation and mechanical ventilation rate. The secondary outcomes were intensive care unit (ICU) and all-cause mortality, ICU length of stay and duration of mechanical ventilation.

RESULTS: Out of the twenty initially screened studies, four studies with a total of 553 patients met the criteria for inclusion and were included in the analysis. Patients given NIV were 38% less likely to be intubated vs. those given oxygen, RR 0.62 (95%CI 0.42,0.93); however, this analysis result is significantly heterogenous. After sensitivity analysis, results showed 48% less likelihood of intubation and mechanical ventilation in the group treated with NIV, RR 0.52 [95% confidence interval (CI) 0.35,0.77]. Patients on NIV had 1.18 days less stay in the ICU vs. oxygen group (95%CI -1.84,-0.52 days ).

Three studies included ICU mortality in their outcomes and showed a 54% decrease in ICU mortality among patients given NIV, RR 0.46 (95% CI 0.17, 1.29), however this result is non-significant and heterogenous I2=58%. There was no statistically significant decrease in all-cause mortality between the two groups, RR 0.77 (95% CI 0.53,1.11). After a sensitivity analysis performed specifically for this outcome, results showed a 32% reduction in all cause mortality in patients given NIV vs. oxygen therapy, however was not statistically significant RR 0.68 (95% CI 0.53-1.11) and was heterogenous I2=50%. There is no difference in the duration of mechanical ventilation between groups.

CONCLUSION: In immunocompromised patients with respiratory failure, NIV reduced intubation rates, and length of ICU stay, compared to standard oxygen therapy. This intervention also showed trend toward ICU and all-cause mortality reduction.

Human ; Noninvasive Ventilation ; Respiration, Artificial ; Oxygen ; Confidence Intervals ; Length Of Stay ; Oxygen Inhalation Therapy ; Respiratory Insufficiency ; Intensive Care Units ; Pneumonia ; Intubation ; Immunocompromised Host

Introduction: Performance on cardiopulmonary exercise test (CPET) is influenced by genetic, racial and environmental factors. It is important to establish a set of reference values for the Filipino population. This study aimed to establish the maximum working capacity, peak oxygen uptake (VO2), peak carbon dioxide output (VCO2), tidal volume (TV) for normal Filipinos during exercise; determine the median perceived rate of exertion using the Borg Scale; and derive prediction equation models for maximum working capacity, peak VO2, peak VCO2 and maximum attained TV. Methods: The maximal cardiopulmonary responses were analyzed for 118 healthy sedentary adult Filipino subjects who underwent CPET using a symptom limited incremental progressive cycle ergometer driven protocol. A Vista MiniCPX Model 17670 was used. Models for predicting VO2 max, VCO2 peak, TV peak, and work max were derived with height, weight, age and sex being screened for significance as predictors. Linear and non-linear regression analyses were done. Results: The maximum working capacity for males was 154.21+26.6 watts and 93.02+15.57 watts for females while the peak VO2 for males was 4.90+3.11 and 4.56 2.41 liters/ minute for females. The predictive formulae derived from this study for maximum work capacity, peak VO2, VCO2 and tidal volume had acceptable correlation coefficients and performed as well as other published predictive equations based on Caucasian and Asian populations. Discussion: Differences between races as to performance in exercise testing was confirmed in this study so that it is worthwhile to utilize predictive equations specific for a certain racial population in the accurate interpretation of results. Performance in an exercise test also depends on the exercise protocol used so that the predictive equations in this study can be used only for exercise tests using a similar protocol. Conclusion Cardiopulmonary exercise testing was performed on a community based, healthy, sedentary Filipino population using a standard maximal incremental cycle ergometry protocol. Predictive equation models were derived for Maximum Working Capacity (r2=0.728), peak VO2 (r2= 0.123), peak VCO2 (r2=0.648), and TV (r2=0.579). The derived predictive formulae performed as well as other published predictive equations.
Exercise Test

OBJECTIVE: To determine the effects of arginine in the rates of sputum conversion in patients with drug-sensitive pulmonary tuberculosis.

METHODS: Studies from PubMed, Medline, EMBASE, and Cochrane were reviewed and appropriate studies were included. Randomized controlled trials comparing arginine with placebo in adult patients with drug-sensitive pulmonary tuberculosis were included. The risk of bias was assessed using the Cochrane Risk of Bias tool. A meta-analysis of the rate of sputum conversion at 8 weeks, was conducted. Post hoc analyses of sputum conversion at 4 weeks and cough reduction at 4 and 8 weeks were done.

RESULTS: Three articles included in this study had a pooled population of 452 participants. This meta-analysis showed no significant difference in the sputum conversion at 4 and 8 weeks, with a relative risk of 0.96 (95% CI 0.77-1.20) and 1.07 (95% CI 0.96-1.19), respectively. However, the cough was significantly reduced at 4 and 8 weeks, with subtotal relative risks of 0.91 (95% CI 0.82-1.00) and 0.43 (95% CI 0.22-0.81), and total relative risk for cough reduction of 0.83 (95% CI 0.73-0.93).

CONCLUSION: While arginine may not significantly reduce sputum conversion rates, it may be used as an adjunct to decrease cough in patients with tuberculosis.

Human ; Arginine ; Tuberculosis, Pulmonary