PDF(Pubmed)
Abstract：
BACKGROUND: Legionella remains underdiagnosed in the intensive care unit and can progress to acute respiratory distress syndrome (ARDS), multiorgan failure and death. In severe cases, venovenous extracorporeal membrane oxygenation (VV-ECMO) allows time for resolution of disease with Legionella-targeted therapy. VV-ECMO outcomes for Legionella are favorable with reported survival greater than 70%. Rapid molecular polymerase chain reaction (PCR) testing of the lower respiratory tract aids in diagnosing Legionella with high sensitivity and specificity. We present a unique case of a patient with a positive COVID-19 test and ARDS who suffered a cardiac arrest. The patient was subsequently cannulated for VV-ECMO, and after lower respiratory tract PCR testing, Legionella was determined to be the cause. She was successfully treated and decannulated from VV-ECMO after eight days.
METHODS: A 53-year-old female presented with one week of dyspnea and a positive COVID-19 test. She was hypoxemic, hypotensive and had bilateral infiltrates on imaging. She received supplemental oxygen, intravenous fluids, vasopressors, broad spectrum antibiotics, and was transferred to a tertiary care center. She developed progressive hypoxemia and suffered a cardiac arrest, requiring ten minutes of CPR and endotracheal intubation to achieve return of spontaneous circulation. Despite mechanical ventilation and paralysis, she developed refractory hypoxemia and was cannulated for VV-ECMO. Dexamethasone and remdesivir were given for presumed COVID-19. Bronchoscopy with bronchoalveolar lavage (BAL) performed with PCR testing was positive for Legionella pneumophila and negative for COVID-19. Steroids and remdesivir were discontinued and she was treated with azithromycin. Her lung compliance improved, and she was decannulated after eight days on VV-ECMO. She was discharged home on hospital day 16 breathing room air and neurologically intact.
CONCLUSIONS: This case illustrates the utility of rapid PCR testing to diagnose Legionella in patients with respiratory failure and the early use of VV-ECMO in patients with refractory hypoxemia secondary to Legionella infection. Moreover, many patients encountered in the ICU may have prior COVID-19 immunity, and though a positive COVID-19 test may be present, further investigation with lower respiratory tract PCR testing may provide alternative diagnoses. Patients with ARDS should undergo Legionella-specific testing, and if Legionella is determined to be the causative organism, early VV-ECMO should be considered in patients with refractory hypoxemia given reported high survival rates.
METHODS: A 53-year-old female presented with one week of dyspnea and a positive COVID-19 test. She was hypoxemic, hypotensive and had bilateral infiltrates on imaging. She received supplemental oxygen, intravenous fluids, vasopressors, broad spectrum antibiotics, and was transferred to a tertiary care center. She developed progressive hypoxemia and suffered a cardiac arrest, requiring ten minutes of CPR and endotracheal intubation to achieve return of spontaneous circulation. Despite mechanical ventilation and paralysis, she developed refractory hypoxemia and was cannulated for VV-ECMO. Dexamethasone and remdesivir were given for presumed COVID-19. Bronchoscopy with bronchoalveolar lavage (BAL) performed with PCR testing was positive for Legionella pneumophila and negative for COVID-19. Steroids and remdesivir were discontinued and she was treated with azithromycin. Her lung compliance improved, and she was decannulated after eight days on VV-ECMO. She was discharged home on hospital day 16 breathing room air and neurologically intact.
CONCLUSIONS: This case illustrates the utility of rapid PCR testing to diagnose Legionella in patients with respiratory failure and the early use of VV-ECMO in patients with refractory hypoxemia secondary to Legionella infection. Moreover, many patients encountered in the ICU may have prior COVID-19 immunity, and though a positive COVID-19 test may be present, further investigation with lower respiratory tract PCR testing may provide alternative diagnoses. Patients with ARDS should undergo Legionella-specific testing, and if Legionella is determined to be the causative organism, early VV-ECMO should be considered in patients with refractory hypoxemia given reported high survival rates.
摘要：
背景：军团菌在重症监护病房中仍未被诊断，并可发展为急性呼吸窘迫综合征（ARDS），多器官衰竭和死亡。在严重的情况下,静脉体外膜氧合（VV-ECMO）为军团菌靶向治疗提供了解决疾病的时间。军团菌的VV-ECMO结果是有利的,报告的存活率大于70%。下呼吸道快速分子聚合酶链反应（PCR）检测有助于以高灵敏度和特异性诊断军团菌。我们介绍了一例COVID-19检测阳性和ARDS患者心脏骤停的独特病例。患者随后接受VV-ECMO插管，下呼吸道PCR检测后，军团菌被确定为病因。八天后，她成功治疗并从VV-ECMO脱管。
方法：一名53岁女性出现一周呼吸困难和COVID-19检测阳性。她是低氧血症,低血压，影像学检查有双侧浸润。她接受了补充氧气,静脉输液,血管升压药,广谱抗生素,并被转移到三级护理中心。她出现了进行性低氧血症，心脏骤停，需要10分钟的CPR和气管内插管以实现自主循环的恢复。尽管机械通气和瘫痪，患者出现难治性低氧血症,接受VV-ECMO插管.对推测的COVID-19给予地塞米松和瑞德西韦。支气管镜支气管肺泡灌洗（BAL）并进行PCR检测，嗜肺军团菌阳性，COVID-19阴性。停用类固醇和瑞德西韦，并接受阿奇霉素治疗。她的肺顺应性改善了,接受VV-ECMO治疗八天后，她被拔管。她在医院第16天出院回家，呼吸室内空气，神经系统完好无损。
结论：本案例说明了快速PCR检测在呼吸衰竭患者中诊断军团菌的实用性，以及在军团菌感染继发的难治性低氧血症患者中早期使用VV-ECMO。此外，在ICU遇到的许多患者可能具有先前的COVID-19免疫力，尽管可能存在阳性的COVID-19测试，下呼吸道PCR检测的进一步研究可能提供替代诊断.ARDS患者应进行军团菌特异性检测，如果确定军团菌是致病生物，对于报道的高生存率的难治性低氧血症患者,应考虑早期VV-ECMO.
方法：一名53岁女性出现一周呼吸困难和COVID-19检测阳性。她是低氧血症,低血压，影像学检查有双侧浸润。她接受了补充氧气,静脉输液,血管升压药,广谱抗生素,并被转移到三级护理中心。她出现了进行性低氧血症，心脏骤停，需要10分钟的CPR和气管内插管以实现自主循环的恢复。尽管机械通气和瘫痪，患者出现难治性低氧血症,接受VV-ECMO插管.对推测的COVID-19给予地塞米松和瑞德西韦。支气管镜支气管肺泡灌洗（BAL）并进行PCR检测，嗜肺军团菌阳性，COVID-19阴性。停用类固醇和瑞德西韦，并接受阿奇霉素治疗。她的肺顺应性改善了,接受VV-ECMO治疗八天后，她被拔管。她在医院第16天出院回家，呼吸室内空气，神经系统完好无损。
结论：本案例说明了快速PCR检测在呼吸衰竭患者中诊断军团菌的实用性，以及在军团菌感染继发的难治性低氧血症患者中早期使用VV-ECMO。此外，在ICU遇到的许多患者可能具有先前的COVID-19免疫力，尽管可能存在阳性的COVID-19测试，下呼吸道PCR检测的进一步研究可能提供替代诊断.ARDS患者应进行军团菌特异性检测，如果确定军团菌是致病生物，对于报道的高生存率的难治性低氧血症患者,应考虑早期VV-ECMO.
