{'fraction_non_alphanumeric': 0.05550883095037847, 'fraction_numerical': 0.049201009251471826, 'mean_word_length': 5.412398921832884, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Factors Associated with Early Invasive Ventilation in Critically Ill Patients with COVID-19: A Single-Centered, Retrospective, Observational Study

Background: Early invasive ventilation can effectively improve oxygenation and delay the disease progression of critically ill patients with coronavirus disease 2019 (COVID-19). The factors associated with early invasive ventilation in these patients have not been determined. 
 
Methods: In this single-centered, retrospective, observational study, we included adult critically ill inpatients with COVID-19 who received invasive ventilation from a designated hospital for severe and critical patients with COVID-19 (Wuhan, China) between Jan 10 and Feb 29, 2020. Demographic, clinical, laboratory, radiological, and treatment data were collected and analyzed. Univariable and multivariable linear regression analyses were used to assess the association between laboratory findings and the duration from hospital admission to invasive ventilation. 
 
Findings: 75 patients with confirmed COVID-19 who received invasive ventilation were included. 63 (84%) patients died and 6 (8%) were weaned off the invasive ventilation by Mar 19, 2020. The median durations from symptom onset to admission and to invasive ventilation were 10.0 days (IQR, 7·0–15·0) and 18·0 days (IQR, 14·0–24·0), respectively. Regression analyses revealed that age (regression coefficient: 0.22, 95% confidence interval [CI], 0·10 to 0·33; P=0·004), lactate dehydrogenase (LDH) (-0·01, -0·01 to -0·00; P=0·014), blood glucose (-0·33, -0·49 to -0·05; P=0·016), and monocyte-to-lymphocyte ratio (MLR) (-1·73, -2·56 to -0·24; P=0·049) were independently associated with the duration from admission to invasive ventilation. 
 
Interpretation: Younger age, as well as higher levels of LDH, blood glucose, and MLR were associated with shorter duration from admission to invasive ventilation in critically ill patients with COVID-19. These potential risk factors may facilitate the identification of rapid disease progression and early requirement for invasive ventilation. 
 
Funding Statement: None. 
 
Declaration of Interests: The authors declare no competing interests. 
 
Ethics Approval Statement: The study was approved by the Institutional Ethics Board of Tongji Hospital (TJ-IRB20200347). Written informed consent was waived by the Institutional Ethics Board