A Clinical Study of Role of Noninvasive Ventilation in Community Acquired Pneumonia Patients with Acute Respiratory Failure – A Prospective Observational Study from Telangana, India

Abstract

BACKGROUND Community-Acquired Pneumonia (CAP) is defined as “an acute infection of the pulmonary parenchyma. The most important complication of CAP is Acute Respiratory Failure (ARF) and some of them may require Invasive Mechanical Ventilation (IMV) to manage hypoxia and hypoventilation along with appropriate antibiotic therapy. A number of studies, however, indicate that IMV is associated with high rates of serious complications and mortality in patients with ARF. For this reason Non-Invasive Ventilation (NIV) has been used for ARF of diverse aetiologies.The most important rationale for using NIV in early stages of respiratory failure is to decrease the workload on respiratory muscles and improve ventilation by applying positive airway pressure. This may help to overcome an episode of severe ARF without the need for MV. In this study we evaluated the efficacy of NIV in patients with ARF and compare the outcome of using NIV in CAP with ARF patients with and without comorbidities. METHODS This prospective observational study was done on 150 CAP patients in acute respiratory failure who received NIV. It was conducted in the Department of Respiratory Medicine in Gandhi Hospital, Secunderabad, for a period of one year and six months. A comparative analysis of the outcome of using NIV in CAP with ARF patients with and without co-morbidities was carried out. RESULTS In the current study 150 CAP patients with ARF who needed NIV, were treated initially with NIV, antibiotic therapy and other supportive measures as per the American Thoracic Society (ATS) guidelines 32. 95 (63.3 %) of 150 patients were continuously treated with NIV. Apart from these, 55 (36.7 %) patients required MV. In patients with continued NIV, 93 (98 %) recovered, remaining 2 died with sudden cardiac arrest. In patients who were gone for MV, 12 (22 %) survived. CONCLUSIONS Early intervention by NIV in CAP patients suffering from acute respiratory failure secondary to community acquired pneumonia was found to be successful in avoiding mechanical ventilation and its attendant morbidity and mortality31. Early intervention with NIV, identifying risk factors for NIV failure, addressing associated co-morbid conditions will go in a long way in effectively managing these patients by significantly minimizing the ICU and hospital stay. Patients with co-morbidities have more chances of NIV failures. Patients with co morbidities on NIV stayed significantly more number of days in the hospital than patients without co-morbidities. The current study suggests that co morbid patients require more monitoring as compared to patients without co morbidities on NIV. KEY WORDS Community-Acquired Pneumonia (CAP), Non-Invasive Ventilation (NIV), Mechanical Ventilation (MV), Acute Respiratory Failure (ARF), Arterial Blood Gas Analysis (ABG), Intensive Care Unit (ICU), Intubation