Clinical research about airway pressure release ventilation for moderate to severe acute respiratory distress syndrome.

OBJECTIVE: To evaluate clinical effects of airway pressure release ventilation (APRV) in patients suffering from moderate to severe acute respiratory distress syndrome (ARDS).e of a patient presented with significant high aminotransferase levels due to the first human R. aeschlimannii infection ever detected in Italy. The hypothesis of rickettsiosis was made on the basis of a comprehensive medical history and was confirmed by serological tests. Molecular analyses made on a sample of hepatic tissue revealed the presence of a rickettsial species never found before in human liver.

PATIENTS AND METHODS: From August 2012 to August 2014, fifty-two cases with moderate to severe ARDS were randomly divided into two groups. In the first group (APRV) the airway pressure release ventilation was used; the second group (SIMV) was ventilated using synchronized intermittent mandatory ventilation mode and positive end expiratory pressure (PEEP). Changes in oxygenation index, respiratory mechanics, extravascular lung water, functional residual capacity change and hemodynamics were recorded in both groups after mechanical ventilation. TNF-a and IL-10 levels in alveolar lavage were also measured. Acute physiology and chronic health evaluation (APACHE) II and Murray scores were evaluated. Pneumothorax and mediastinal emphysema during ventilation were also recorded. The probability of survival, the duration of ICU stay, days without organ failure and days without sedation were compared.

RESULTS: Conditions in APRV were improved significantly. Oxygenation index was increased, airway peak pressure (Ppeak) was reduced, the lung dynamic compliance improved, extravascular lung water was relieved, functional residual capacity increased and Murray score was improved. In APRV group ventilation central venous pressure (CVP) and systemic circulation resistance index (SVRI) were reduced, but cardiac index (CI) increased, and at the same time lac and oxygen saturation of central venous blood (ScvO2) were improved. Free sedatives days were significantly reduced in APRV group while days without mechanical ventilation were increased and days in ICU were shortened significantly. TNF-α and IL-10 concentrations in the alveolar lavage, probability of survival and days without organ failure were similar in both groups.

CONCLUSIONS: In patients suffering from moderate to severe ARDS, application of APRV improved lung function and hemodynamics. It also reduced the need for sedatives and the duration of mechanical ventilation as well as days in ICU.