每日一题_2022.5.19

A 58-year-old man is in the ICU three days after being involved in a motor vehicle accident. His injuries include bilateral pulmonary contusions, rib fractures, splenic laceration, femur fracture, and multiple superficial lacerations. He has been weaned off vasoactive medications, and is on a continuous infusion of fentanyl for analgesia. Chest radiograph shows bilateral airspace opacities. Echocardiogram obtained yesterday shows no obvious abnormality and an estimated ejection fracture greater than 55%. He remains on mechanical ventilation for support of his hypoxemic respiratory failure. He is spontaneously breathing, with a respiratory rate of 18 breaths/min. His current mode of ventilation is airway pressure release ventilation on the following settings: positive end- expiratory pressure (PEEP)-high 25 cm H2O, PEEP-low 0 cm H2O, time (T)-high 6.75, T-low 0.75 sec., fraction of inspired oxygen 0.5.

Which of the following is a current criteria for the diagnosis of ARDS?

A. Timing of onset greater than one week 

B. PEEP greater than 10cmH2O

C. Absence of left ventricular dysfunction on echocardiography 

D. Treatment not impacted by degree of hypoxemia

答案解析：

急性呼吸窘迫综合征(ARDS)的危险分层为轻度、中度和重度，使临床医生能够对缺氧患者进行标记，并提供循证治疗策略。作为重症监护医师，对该严重程度量表的基本了解将有助于急性管理。2011年柏林定义指出，“ARDS是一种急性弥漫性、炎性肺损伤，可导致肺血管通透性增加、肺重量增加和充气肺组织损失[伴]低氧血症和双侧放射学阴影，与静脉混合物增加相关，生理死腔增加，肺顺应性降低。”发作时间必须在已知临床损伤或新发或恶化的呼吸道症状的一周内。氧合定义基于动脉血氧分压(PaO2)与吸入氧分数(FIO2)的比值，患者接受至少5 cm H2O呼气末正压(PEEP)：轻度(200 mmHg < PaO2：FIO2≤300 mmHg)、中度(100 mmHg < PaO2：FIO2≤200 mmHg)、重度(≤100 mmHg)。为诊断ARDS，必须排除心源性肺水肿。治疗方案的差异取决于低氧血症的程度和ARDS的严重程度，包括PEEP滴定。

正确答案：C

补充内容：

满足以下四项条件方可诊断为ARDS：①明确诱因下1周内出现的急性或进展性呼吸困难。②胸部X线平片/CT显示双肺浸润影，不能完全用胸腔积液、肺叶/全肺不张和结节影解释。③呼吸衰竭不能完全用心力衰竭、液体负荷过重解释。④根据氧合指数诊断。