Yuwei Zheng,1,* Chaochao Chen,1,* Xiaojie Bi,1,* Xiaowei Li,2 Jing Wang,1,3 Yufen Zheng,1,3 Yuan Yuan,1 Yongpo Jiang,4 Bo Shen,1,3 Yinghe Xu4 

1Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, Zhejiang, People’s Republic of China; 2Department of Pathology, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, Zhejiang, People’s Republic of China; 3Key Laboratory of System Medicine and Precision Diagnosis and Treatment of Taizhou, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, Zhejiang, People’s Republic of China; 4Department of Critical Care Medicine, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, Zhejiang, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Yinghe Xu, Department of Critical Care Medicine, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, No. 150, Ximen Road, Linhai, Taizhou, Zhejiang, 317000, People’s Republic of China, Email xuyh@enzemed.com Bo Shen, Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, Zhejiang, People’s Republic of China, Email shenb@enzemed.com

Purpose: The role of prone position (PP) in critically ill patients diagnosed with coronavirus disease 2019 (COVID-19) undergoing invasive mechanical ventilation remains unclear. This study aimed to evaluate the potential prognostic benefits of PP.
Patients and methods: This retrospective study included data from 289 critically ill patients with COVID-19 who underwent invasive mechanical ventilation in a multicenter setting. Propensity score matching was used to match 156 patients (78 PP-treated, 78 non-PP-treated) after adjusting for age, sex, underlying disease, and Sequential Organ Failure Assessment score. Between-group comparisons of clinical data, laboratory results, and prognosis were performed. Kaplan–Meier (K–M) survival curve and univariate and multivariate Cox regression analyses were used to explore the relationship between PP and prognosis.
Results: Prone positioning improved oxygenation (oxygenation index in the PP group increased consistently, with the greatest improvement observed on days 12– 13 compared with the non-PP group [48 vs 32 mmHg; P < 0.001]) and increased hospital survival (80.8% vs 65.4%; P = 0.047). K–M survival curve analysis revealed that patients treated with PP had a more favorable prognosis (P = 0.025). Multivariate Cox regression revealed that PP was linked to lower risk of death (HR 0.389 [95% CI 0.173– 0.878]), while age (HR 1.053 [95% CI 1.012– 1.096]), Acute Physiology and Chronic Health Evaluation II score (HR 1.055 [95% CI 1.006– 1.107]), and troponin T levels (HR 2.028 [95% CI 1.222– 3.367]) were linked to higher risk of death in the overall survival of patients with COVID-19.
Conclusion: PP improved oxygenation and increased the survival rate of critically ill patients with COVID-19 undergoing invasive mechanical ventilation. Adopting PP as much as possible during nursing care may enhance patient survival.

Keywords: COVID-19, prone position, mechanical ventilation, survival, prognosis