Abstract:

Objective  To analyze the clinical characteristics of elderly patients with COVID⁃19 receivinginvasive mechanical ventilation. Methods  In this retrospective，single⁃center cohort study，we included twocohorts of elderly（age ≥ 60 years）inpatients with laboratory confirmed COVID⁃19 from Wuhan NO.1 Hospital（Wuhan，China）. They were divided into two groups：20 patients received tracheal intubation and invasivemechanical ventilation，and 30 patients in the control group did not undergo invasive mechanical ventilation duringhospitalization，and finally recovered and discharged. Demographic，clinical，treatment，and laboratory data wereextracted from electronic medical records and compared between these two groups. Results The age range ofpatients in the invasive ventilation group ranged from 64 ~ 83 years，with a median age of 71.5 years（IQR 67.0，79.8），and a sex ratio of 13：7. More than half of the patients had underlying diseases，the most common of whichwas hypertension， Comorbidities were present in nearly half of patients in both groups，with hypertension beingthe most common comorbidity，followed by coronary heart disease and diabetes. The most common symptoms onadmission were fever and cough，followed by sputum and chest tightness. The critically ill patients in the invasiveventilation group accounted for 65% and 25% of the patients with severe disease，which were significantly higherthan the control group（P = 0.000）. Chest CT showed lung consolidation in the invasive ventilation group was 75%，which was significantly higher than that of the control group（47%）（P = 0.047）. The patients′ lymphocyte count （1.13 ± 0.63 ）× 10^9/L，lymphocyte percentage（4.16 ± 3.45）%，serum albumin（27.14 ± 4.42）g/L in the invasiveventilation group were significantly lower than the control group（all P = 0.000）；The concentrations of D⁃dimer，CRP，LDH，and BUN were significantly higher than those of the control group（all P = 0.000）. All patientsreceived antiviral treatment. In the invasive ventilation group，18 patients（90%）received glucocorticoids，signifi⁃cantly higher than the control group（27%）（P = 0.000）. Before invasive mechanical ventilation，17 patients（85%）were given noninvasive mechanical ventilation，and 2 patients（15%）were given high⁃flow nasal cannula oxygen.In the process of endotracheal intubation for patients in the invasive ventilation group，medical staff adopted threelevels of protection. After induction of anesthesia，the blood pressure and heart rate of the patients decreased signif⁃icantly（P < 0.05）. Conclusion The potential risk factors of heavier clinical typing on admission，lower peripheralblood lymphocyte counts，heavier inflammation，lower serum albumin levels can help clinicians to identify elderlypatients who needed invasive mechanical ventilation at an early stage. Anesthetic agents should be used carefullyduring tracheal intubation to ensure patients′ safety. The medical staff should have a high⁃evel protection duringthe intubation to maximally ensure their safety.

Key words: COVID?19, elderly, tracheal intubation, mechanical ventilation, respiratory failure