Abstract：
BACKGROUND: Ventilator-associated lower respiratory tract infections (VA-LRTI) increase morbidity and mortality in intensive care unit (ICU) patients. Higher incidences of VA-LRTI have been reported among COVID-19 patients requiring invasive mechanical ventilation (IMV). The primary objectives of this study were to describe clinical characteristics, incidence, and risk factors comparing patients who developed VA-LRTI to patients who did not, in a cohort of Swedish ICU patients with acute hypoxemic respiratory failure due to COVID-19. Secondary objectives were to decipher changes over the three initial pandemic waves, common microbiology and the effect of VA-LTRI on morbidity and mortality.
METHODS: We conducted a multicenter, retrospective cohort study of all patients admitted to 10 ICUs in southeast Sweden between March 1, 2020 and May 31, 2021 because of acute hypoxemic respiratory failure due to COVID-19 and were mechanically ventilated for at least 48 h. The primary outcome was culture verified VA-LRTI. Patient characteristics, ICU management, clinical course, treatments, microbiological findings, and mortality were registered. Logistic regression analysis was conducted to determine risk factors for first VA-LRTI.
RESULTS: Of a total of 536 included patients, 153 (28.5%) developed VA-LRTI. Incidence rate of first VA-LRTI was 20.8 per 1000 days of IMV. Comparing patients with VA-LRTI to those without, no differences in mortality, age, sex, or number of comorbidities were found. Patients with VA-LRTI had fewer ventilator-free days, longer ICU stay, were more frequently ventilated in prone position, received corticosteroids more often and were more frequently on antibiotics at intubation. Regression analysis revealed increased adjusted odds-ratio (aOR) for first VA-LRTI in patients treated with corticosteroids (aOR 2.64 [95% confidence interval [CI]] [1.31-5.74]), antibiotics at intubation (aOR 2.01 95% CI [1.14-3.66]), and days of IMV (aOR 1.05 per day of IMV, 95% CI [1.03-1.07]). Few multidrug-resistant pathogens were identified. Incidence of VA-LRTI increased from 14.5 per 1000 days of IMV during the first wave to 24.8 per 1000 days of IMV during the subsequent waves.
CONCLUSIONS: We report a high incidence of culture-verified VA-LRTI in a cohort of critically ill COVID-19 patients from the first three pandemic waves. VA-LRTI was associated with increased morbidity but not 30-, 60-, or 90-day mortality. Corticosteroid treatment, antibiotics at intubation and time on IMV were associated with increased aOR of first VA-LRTI.
METHODS: We conducted a multicenter, retrospective cohort study of all patients admitted to 10 ICUs in southeast Sweden between March 1, 2020 and May 31, 2021 because of acute hypoxemic respiratory failure due to COVID-19 and were mechanically ventilated for at least 48 h. The primary outcome was culture verified VA-LRTI. Patient characteristics, ICU management, clinical course, treatments, microbiological findings, and mortality were registered. Logistic regression analysis was conducted to determine risk factors for first VA-LRTI.
RESULTS: Of a total of 536 included patients, 153 (28.5%) developed VA-LRTI. Incidence rate of first VA-LRTI was 20.8 per 1000 days of IMV. Comparing patients with VA-LRTI to those without, no differences in mortality, age, sex, or number of comorbidities were found. Patients with VA-LRTI had fewer ventilator-free days, longer ICU stay, were more frequently ventilated in prone position, received corticosteroids more often and were more frequently on antibiotics at intubation. Regression analysis revealed increased adjusted odds-ratio (aOR) for first VA-LRTI in patients treated with corticosteroids (aOR 2.64 [95% confidence interval [CI]] [1.31-5.74]), antibiotics at intubation (aOR 2.01 95% CI [1.14-3.66]), and days of IMV (aOR 1.05 per day of IMV, 95% CI [1.03-1.07]). Few multidrug-resistant pathogens were identified. Incidence of VA-LRTI increased from 14.5 per 1000 days of IMV during the first wave to 24.8 per 1000 days of IMV during the subsequent waves.
CONCLUSIONS: We report a high incidence of culture-verified VA-LRTI in a cohort of critically ill COVID-19 patients from the first three pandemic waves. VA-LRTI was associated with increased morbidity but not 30-, 60-, or 90-day mortality. Corticosteroid treatment, antibiotics at intubation and time on IMV were associated with increased aOR of first VA-LRTI.
摘要：
背景：呼吸机相关下呼吸道感染（VA-LRTI）增加重症监护病房（ICU）患者的发病率和死亡率。据报道，在需要有创机械通气（IMV）的COVID-19患者中，VA-LRTI的发生率更高。这项研究的主要目的是描述临床特征，发病率,并将发生VA-LRTI的患者与未发生VA-LRTI的患者进行比较，在一组因COVID-19导致急性低氧性呼吸衰竭的瑞典ICU患者中。次要目标是破译最初三次大流行浪潮的变化，常见微生物学和VA-LTRI对发病率和死亡率的影响。
方法：我们进行了多中心，对2020年3月1日至2021年5月31日因COVID-19导致急性低氧性呼吸衰竭而在瑞典东南部10个ICU住院的所有患者进行回顾性队列研究,并机械通气至少48小时。主要结局是经过培养验证的VA-LRTI.患者特征,ICU管理,临床课程，治疗,微生物学发现，和死亡率登记。进行Logistic回归分析以确定首次VA-LRTI的危险因素。
结果：在总共536名患者中，153（28.5%）开发了VA-LRTI。首次VA-LRTI的发生率为每1000天IMV20.8。将有VA-LRTI的患者与没有VA-LRTI的患者进行比较，死亡率没有差异，年龄,性别,或发现合并症的数量。VA-LRTI患者的无呼吸机天数较少，ICU停留时间更长,更频繁地在俯卧位通风，在插管时更频繁地接受皮质类固醇,并且更频繁地使用抗生素.回归分析显示，使用皮质类固醇治疗的患者首次VA-LRTI的校正比值比（aOR）增加（aOR为2.64[95％置信区间[CI]][1.31-5.74]），插管时的抗生素（aOR2.0195%CI[1.14-3.66]），和IMV天数(IMV每天aOR1.05，95%CI[1.03-1.07]）。很少发现多药耐药病原体。VA-LRTI的发生率从第一波中每1000天IMV的14.5增加到随后波的每1000天IMV的24.8。
结论：我们报告了前三个大流行波中的一组危重COVID-19患者中培养验证的VA-LRTI的发生率很高。VA-LRTI与发病率增加相关，但不是30-，60-,或90天死亡率。皮质类固醇治疗,插管时的抗生素和IMV时间与首次VA-LRTI的aOR增加相关.
方法：我们进行了多中心，对2020年3月1日至2021年5月31日因COVID-19导致急性低氧性呼吸衰竭而在瑞典东南部10个ICU住院的所有患者进行回顾性队列研究,并机械通气至少48小时。主要结局是经过培养验证的VA-LRTI.患者特征,ICU管理,临床课程，治疗,微生物学发现，和死亡率登记。进行Logistic回归分析以确定首次VA-LRTI的危险因素。
结果：在总共536名患者中，153（28.5%）开发了VA-LRTI。首次VA-LRTI的发生率为每1000天IMV20.8。将有VA-LRTI的患者与没有VA-LRTI的患者进行比较，死亡率没有差异，年龄,性别,或发现合并症的数量。VA-LRTI患者的无呼吸机天数较少，ICU停留时间更长,更频繁地在俯卧位通风，在插管时更频繁地接受皮质类固醇,并且更频繁地使用抗生素.回归分析显示，使用皮质类固醇治疗的患者首次VA-LRTI的校正比值比（aOR）增加（aOR为2.64[95％置信区间[CI]][1.31-5.74]），插管时的抗生素（aOR2.0195%CI[1.14-3.66]），和IMV天数(IMV每天aOR1.05，95%CI[1.03-1.07]）。很少发现多药耐药病原体。VA-LRTI的发生率从第一波中每1000天IMV的14.5增加到随后波的每1000天IMV的24.8。
结论：我们报告了前三个大流行波中的一组危重COVID-19患者中培养验证的VA-LRTI的发生率很高。VA-LRTI与发病率增加相关，但不是30-，60-,或90天死亡率。皮质类固醇治疗,插管时的抗生素和IMV时间与首次VA-LRTI的aOR增加相关.
