Objective: To investigate the effect of pulmonary vascular dysfunction in the prognosis of patients with acute lung injury (ALI).
Methods: Patients with ALI who underwent pulmonary artery catheterization in the department of critical care medicine of Wuhan NO.1 Hospital from June 2017 to June 2019 were enrolled. The general information, clinical and hemodynamic indexes [central venous pressure (CVP), pulmonary artery wedge pressure (PAWP), pulmonary artery systolic pressure (sPAP), pulmonary artery diastolic pressure (dPAP), mean pulmonary artery pressure (mPAP), cardiac index (CI)], acute physiology and chronic health evaluation II (APACHE II) score, arterial blood gas parameters [pH, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), oxygenation index (PaO2/FiO2)], whether there was shock or not; ventilator parameters [platform pressure (Plat), positive end-expiratory pressure (PEEP)], etc. were recorded. Pulmonary artery oxygen saturation, pulmonary vascular function indexes [transpulmonary potential gradient (TPG) and pulmonary vascular resistance index (PVRi)] were calculated. The relationship between TPG, PVRi and mechanical ventilation time, the length of intensive care unit (ICU) stay, cardiovascular days and 60-day mortality were analyzed in patients with different prognosis of 60-day and whether the TPG increased (≥ 12 mmHg was defined as elevated TPG, 1 mmHg = 0.133 kPa).
Results: A total of 65 patients were included in the study, including 30 males and 35 females; aged (48.9±15.2) years old. Forty-eight cases survived in 60-days, 17 died, and the 60-day mortality was 26.2%. At the baseline, there were no significant differences in cardiopulmonary function measurements, such as CVP, sPAP, dPAP, PAWP, CI, etc. between the two groups of patients with different prognosis. The APACHE II score, shock ratio, TPG and PVRi of the death group were significant higher than those of the survival group [APACHE II: 34±9 vs. 28±11, shock: 52.9% vs. 25.0%, TPG (mmHg): 16.2±1.9 vs. 14.6±2.1, PVRi (kPa×s×L-1): 31.8±4.2 vs. 29.7±3.5, all P < 0.05]. The 60-day mortality of 47 patients with TPG ≥ 12 mmHg was significantly higher than that of 18 patients with TPG < 12 mmHg (34.0% vs. 5.6%), and the mechanical ventilation time and the length of ICU stay were also significantly longer (days: 17±9 vs. 11±8, 16±5 vs. 12±5), and the cardiovascular days also increased significantly (days: 23±7 vs. 18±6), and the differences were statistically significant (all P < 0.05). Pearson correlation analysis showed that PVRi was significantly correlated with mechanical ventilation time, the length of ICU stay and cardiovascular days (r1 = 0.317, P1 = 0.030; r2 = 0.277, P2 = 0.005; r3 = 0.285, P3 = 0.002). In the individual multivariate Logistic regression model, the highest PVRi was an independent risk factor for the 60-day mortality [odds ratio (OR) = 30.5, 95% confidence interval was 20.4-43.1, P = 0.023].
Conclusions: Pulmonary vascular dysfunction is common in ALI patients and is independently associated with adverse outcomes.