The association between documented right ventricular dysfunction and in-hospital mortality in mechanically ventilated critically ill patients receiving a noradrenaline infusion: A retrospective observational cohort study.

OBJECTIVE: To determine the documentation of right ventricular dysfunction (RVD) in mechanically ventilated patients receiving a noradrenaline infusion, and to assess the association with in-hospital mortality, length of stay (LOS) and treatment intensity. DESIGN AND SETTING: This single-centre, retrospective, observational cohort study included patients admitted to the intensive care unit (ICU) between January 2020 and December 2023, with elevated serum lactate levels, who received invasive mechanical ventilation and an intravenous noradrenaline infusion, within the first 7 days. INTERVENTIONS: Exposure was defined on the basis of documentation of RVD in the medical record; e.g. those with RVD vs those without RVD. MAIN OUTCOME MEASURES: The primary outcome was in-hospital mortality. Secondary outcomes included ICU mortality, ICU and hospital LOS, organ support modalities, and the utilisation of echocardiography. Comparison between groups utilised logistic and linear regression models. RESULTS: Of 1234 patients included in the study, 273 had documented RVD (22.1%). There was no difference in crude in-hospital mortality (RVD, 24.9% vs no RVD, 23.6% p = 0.66) between groups. Risk-adjusted in-hospital (odds ratio [OR]: 1.65: 1.13-2.41, p = 0.01) and ICU mortality (OR: 1.88: 1.26-2.81, p = 0.002) were greater in those with documented RVD. Median ICU (13.4 vs 10.2 days, p = 0.001) and hospital (25.1 vs 22.5 days, p = 0.002) LOS were significantly longer in the RVD group. A greater number of interventions were provided in those with RVD, including: inhaled nitric oxide (39.6% vs 7.8%, p < 0.001), epoprostenol (1.8% vs 0.1%, p < 0.001), milrinone infusion (77.3% vs 23.6%, p < 0.001), continuous renal replacement therapy (48.7% vs 25.8%, p < 0.001), and extracorporeal membrane oxygenation (33.7% vs 10.4%, p < 0.001). The median number of transthoracic (TTE) or transoesophageal echocardiography (TOE) was 3 (interquartile range [IQR]: 1-4) in those with RVD, compared to 1 (IQR: 1-2) in those without RVD (p < 0.001). CONCLUSION: Approximately 1 in 4 patients who were mechanically ventilated and receiving noradrenaline had documented RVD, which was associated with a higher risk-adjusted in-hospital mortality, longer LOS, and greater treatment intensity.