(381) Clinical Application of Prognostic Scores in Acute Respiratory Distress Syndrome (ARDS) Patients

Introduction: The hallmarks of ARDS include lung injury, increased pulmonary vascular permeability and diffuse inflammatory dysregulation resulting in impaired gas exchange and decreased lung compliance. As ARDS carries a mortality rate of approximately 35%, many prognostic markers have been studied such as the ratio of partial pressure of arterial oxygen (PaO2) to the fraction of inspired oxygen (FiO2) (P/F). This retrospective cohort study aims to investigate the real-world usage of prognostic scores in the management of ARDS.

Methods: A total of 236 patients who were admitted to the medical intensive care unit were identified from the Cleveland Clinic database. 130 ARDS patients with available ventilatory settings were included. The following scores were calculated on day 1 (D1), day 2 (D2) and day 3 (D3) of intubation: P/F, PaO2/FiO2xPEEP ratio (P/FP), Oxygenation Index (OI), Oxygenation Saturation Index (OSI), Dead-Space-to-Tidal-Volume Ratio (VD/VT), Ventilatory Ratio (VR), Driving Pressure (DP) and Mechanical Power (MP). Univariate analysis was done with mortality being the outcome.

Results: Regarding P/F and P/FP, 121 out of 130 patients (93%) had a computable ratio on D1 which was higher than that on D2 (74.6%) and D3 (61.5%). A higher PF ratio at D3 was associated with a lower risk of mortality (OR = 0.51, 95% CI 0.29-0.91). For the OS and OSI, 100% of patients had a measurable value on D1 but decreased to 71.5% and 59.2% on D2 and D3, respectively. With respect to VD/VT, 34.6% had a computable ratio on D1 which decreased to 27.6% on D2 and 24.6% on D3. As for DP, 26.1%, 15.3% and 21.5% of patients had a measurable value on D1, D2 and D3, respectively. 86.9% of patients had a quantifiable VR on D1 which decreased to 66.9% on D2 and 54.6% on D3. A VR > 2 on D3 was associated with a higher risk of mortality (OR = 2.87, 95% CI 1.08-7.59). Lastly, for MP, 87.6% had a value on D1 while 77.7% and 74.6% had a value on D2 and D3, respectively.

Conclusions: In summary, despite prior evidence that the above-mentioned scores have a prognostication value, physicians have yet to routinely employ them in their management. A deeper comprehension of the ARDS severity and prognostic stratification will reinforce physicians to routinely utilize these prognostic scores.