Department of Anesthesia and Intensive Care Medicine, Osaka University Graduate School of Medicine, Osaka, Japan.
Department of Anesthesia, Rinku General Medical Center, Osaka, Japan.
Respir Care. 2023 Aug;68(8):1075-1086. doi: 10.4187/respcare.10567. Epub 2023 May 23.
Prone positioning and neuromuscular blocking agents (NMBAs) are frequently used to treat severe respiratory failure from COVID-19 pneumonia. Prone positioning has shown to improve mortality, whereas NMBAs are used to prevent ventilator asynchrony and reduce patient self-inflicted lung injury. However, despite the use of lung-protective strategies, high death rates in this patient population have been reported.
We retrospectively examined the factors affecting prolonged mechanical ventilation in subjects receiving prone positioning plus muscle relaxants. The medical records of 170 patients were reviewed. Subjects were divided into 2 groups according to ventilator-free days (VFDs) at day 28. Whereas subjects with VFDs < 18 d were defined as prolonged mechanical ventilation, subjects with VFDs ≥18 d were defined as short-term mechanical ventilation. Subjects' baseline status, status at ICU admission, therapy before ICU admission, and treatment in the ICU were studied.
Under the proning protocol for COVID-19, the mortality rate in our facility was 11.2%. The prognosis may be improved by avoiding lung injury in the early stages of mechanical ventilation. According to multifactorial logistic regression analysis, persistent SARS-CoV-2 viral shedding in blood ( = .03), higher daily corticosteroid use before ICU admission ( = .007), delayed recovery of lymphocyte count ( < .001), and higher maximal fibrinogen degradation products ( = .039) were associated with prolonged mechanical ventilation. A significant relationship was found between daily corticosteroid use before admission and VFDs by squared regression analysis (y = -0.00008522x + 0.01338x + 12.8; x: daily corticosteroids dosage before admission [prednisolone mg/d]; y: VFDs/28 d, R = 0.047, = .02). The peak point of the regression curve was 13.4 d at 78.5 mg/d of the equivalent prednisolone dose, which corresponded to the longest VFDs.
Persistent SARS-CoV-2 viral shedding in blood, high corticosteroid dose from the onset of symptoms to ICU admission, slow recovery of lymphocyte counts, and high levels of fibrinogen degradation products after admission were associated with prolonged mechanical ventilation in subjects with severe COVID-19 pneumonia.
俯卧位通气和神经肌肉阻滞剂（NMBA）常被用于治疗 COVID-19 肺炎引起的严重呼吸衰竭。俯卧位通气已被证明可提高死亡率，而 NMBA 则用于预防呼吸机不同步和减少患者的肺损伤。然而，尽管采用了肺保护策略，但据报道，该患者人群的死亡率仍然很高。
我们回顾性研究了接受俯卧位通气加肌松剂的患者中影响机械通气时间延长的因素。回顾性分析了 170 例患者的病历。根据第 28 天的无机械通气天数（VFDs）将患者分为两组。VFDs＜18 d 的患者定义为机械通气时间延长，VFDs≥18 d 的患者定义为短期机械通气。研究了患者的基线状态、入住 ICU 时的状态、入住 ICU 前的治疗以及 ICU 内的治疗。
根据 COVID-19 的俯卧位方案，我们机构的死亡率为 11.2%。通过避免机械通气早期的肺损伤，可能会改善预后。根据多因素逻辑回归分析，血液中持续存在 SARS-CoV-2 病毒脱落（ =.03）、入住 ICU 前每日皮质类固醇用量较高（ =.007）、淋巴细胞计数恢复延迟（ <.001）和纤维蛋白原降解产物最高值较高（ =.039）与机械通气时间延长相关。通过平方回归分析发现，入住 ICU 前每日皮质类固醇使用量与 VFDs 之间存在显著关系（y=-0.00008522x+0.01338x+12.8；x：入住 ICU 前每日皮质类固醇剂量[泼尼松龙 mg/d]；y：28 天 VFDs，R=0.047， =.02）。回归曲线的峰值出现在等效泼尼松龙剂量为 78.5 mg/d 的 13.4 d，这对应最长的 VFDs。
COVID-19 重症肺炎患者血液中持续存在 SARS-CoV-2 病毒脱落、从症状发作到入住 ICU 时较高的皮质类固醇剂量、淋巴细胞计数恢复缓慢以及入住后的纤维蛋白原降解产物水平较高与机械通气时间延长相关。
