[Clinical analysis of non-invasive positive pressure ventilation in immunocompromised host with acute respiratory failure].

Objective To evaluate the value of non-invasive positive pressure ventilation (NPPV) in immunocompromised host (ICH) complicated by acute respiratory failure (ARF), and to investigate predictive variables of success with NPPV in ICH with ARF. MethodsA retrospective study of immunocompromised patients with ARF, who were admitted to respiratory intensive care unit (RICU) from March 2008 to March 2011, was performed. Based on clinical data, univariate Logistic regression was done for prediction for independent factors affecting the success of NPPV treatment. Immunization status was assessed according to clinical outcome. Results NPPV was instituted in all 33 cases with ARF initially.Among these patients, 9 patients (27. 3％) received sequential invasive mechanical ventilation (IMV, failure group ) and all of them died finally; among 24 cases (72.7％) who only received NPPV (success group),7 patients died (29. 2％). There was significant difference between the two groups in mortality (P＜0.01).The simplified acute physiology score Ⅱ (SAPS Ⅱ ) in the success group was lower than that in the failure group (33±9 vs. 43±5, P＜0. 01). However, other clinical data showed no statistical significance between two groups. Univariate Logistic regression analysis identified SAPS Ⅱ was the independent factor associated with the success of NPPV treatment [odds ratio (OR) =0.83, 95％ confidence interval (95％ CI) 0. 709-0. 964, P＜0. 05]. And SAPS Ⅱ ≥38 was a risk factor for the failure of NPPV [area under receiver operating characteristic (ROC) curve 0. 73]. In addition, the lung injury scores (LIS) in the survival group was significantly lower than that of the death group (1.95±0.48 vs. 2. 57±0. 52, P＜0.01), the difference was statistically significant. CD3+ and CD8+ T counts in the survivors were higher than that of non-survivors (CD3+∶0.73±0.16 vs. 0.41±0.20; CD8+∶ 0.51±0.18 vs. 0.21±0.15, both P＜0.01), and the difference was statistically significant. Conclusion As an early treatment for ICH with pulmonary infections suffering from ARF, NPPV can be effective for the ICH patients suffering from severe pulmonary infection through improving hypoxemia, ameliorating respiratory distress symptoms, and avoiding complications associated with IMV when SAPS Ⅱ is less than 38. CD3+ , CD8+ , and the LIS can be used to evaluate the prognosis of those patients. Key words: Non-invasive positive pressure ventilation;  Immunocompromised;  Acute respiratory failure ;  Prognosis