Reliability of Respiratory System Compliance Calculation During Assisted Mechanical Ventilation: A Retrospective Study.

Abstract

To compare respiratory system compliance (C rs ) calculation during controlled mechanical ventilation (MV) and, subsequently, during assisted MV. This is a single-center, retrospective, observational study. This study was conducted on patients admitted to Neuro-ICU of Niguarda Hospital (tertiary referral hospital). We analyzed every patient greater than or equal to 18 years old having a C rs measurement in controlled and in assisted MV within 60 minutes. Plateau pressure (P plat ) was considered reliable if it was deemed visually stable for at least 2 seconds. Inspiratory pause was incorporated to detect P plat in controlled and assisted MV. Calculation of C rs and driving pressure were achieved. A total of 101 patients were studied. An acceptable agreement was found (Bland-Altman plot bias -3.9, level of agreement upper 21.6, lower -29.6). C rs in assisted MV was 64.1 (52.6-79.3) and in controlled MV it was 61.2 (50-71.2) mL/cm H 2o ( p = 0.006). No statistical difference was found in C rs (assisted vs controlled MV) when peak pressure was lower than P plat nor when peak pressure was higher than P plat . A P plat visually stable for at least 2 seconds leads to reliable C rs calculation during assisted MV.