Background and Goal of Study: The effectiveness of non-invasive positive pressure ventilation (NPPV) in acute hypoxaemic respiratory failure varies widely because of it's heterogeneous etiology. There is not enough evidence to support the superiority of NPPV in comparison to IPPV. But it is established that NPPV in adults with acute respiratory distress syndrome (ARDS) improves the oxygenation, reduces the work of breathing and decreases the incidence of ventilator-associated pneumonia. The goal of our study is to estimate the value of NPPV in patients with caused by community acquired pneumonia (CAP) mild to moderate ARDS.
Materials and Methods: We observed 55 patients with mild to moderate ARDS, caused by CAP. Patients were separated in two groups: a prospective NPPV group of 33 patients for the period between 01.01.2015 and 01.12.2016 and a retrospective IPPV group of 22 patients in the period between 01.01.2014 and 01.01.2015. We compared the demographic characteristics, SAPS II score, time of onset of ventilation, results of blood gas analysis on admission, 1st and 24th hour from the start of ventilation, length of ICU stay, days of ventilation and mortality.
Results and Discussion: In comparison to IPPV, NPPV improved gas exchange, avoided intubation in 28 patients and significantly decreased ICU mortality. We represent the main results of our study (the mean values of the researched variables with their standard deviation):

SAPS score:	NPPV group - 37.9 ± 18.47, IPPV group - 30.9 ± 10.34, p=NS;
Respiratory rate on admission:	NPPV group - 31.44 ± 6.11, IPPV group - 29.55 ± 3.9, p=NS;
PaO2/FiO2 on admission:	NPPV group - 135.02 ± 32.44, IPPV group - 127.5 ± 23.73, p=NS;
PaO2/FiO2 after 1h:	NPPV group - 148.99 ± 48.6, IPPV group - 73.35 ± 19.5, p <0.001;
PaO2/FiO2 after 24h:	NPPV group - 157.74 ± 68.97, IPPV group - 81.82 ± 32.2, p<0.001;
Onset of ventilation (min after admission): NPPV group - 46.5 ± 12, IPPV group - 190.5 ± 50, p<0.001;
ICU length of stay (days): NPPV group -	7.4 ± 4.1, IPPV group - 13.7 ± 3.2, p<0.05;
Duration of ventilation (days):	NPPV group - 4.09 ± 2.7, IPPV group - 10.07 ± 2.8, p<0.05;
Mortality (%): NPPV group - 4.5%, IPPV group - 59.1%, p<0.001.


Conclusion: In severe community acquired pneumonia with mild to moderate ARDS without signs of shock and multi-organ failure early application of NPPV lowers the frequency of intubation, the complications, associated with invasive ventilation, and the overall mortality.

Estimation of the role of noninvasive positive pressure ventilation (NPPV) and invasive positive pressure ventilation (IPPV) in patients with mild to moderate ARDS, caused by community acquired pneumonia