Yousefshahi Fardin, Samadi Elham, Paknejad Omalbanin, Movafegh Ali, Barkhordari Khosro, Bastan Hagh Ehsan, Dehestani Babak
Department of Anesthesiology, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran.
Kelvington Hospital, Kelvington, Saskatchewan, Canada.
J Tehran Heart Cent. 2019 Apr;14(2):74-80.
Acute hypoxemia is the main characteristic of acute respiratory distress syndrome (ARDS), which is one of the most critical complications of coronary artery bypass grafting (CABG). Given the dearth of data on acute hypoxemia, we sought to determine its prevalence and risk factors among post-CABG patients. This cross-sectional study was conducted on on-pump CABG patients in Tehran Heart Center in 2 consecutive months in 2012. The effects of arterial blood gas variables, age, gender, the duration of the pump and cross-clamping, the ejection fraction, the creatinine level, and the body mass index on the prevalence of hypoxemia at the cutoff points of ARDS and acute lung injury were assessed. Out of a total of 232 patients who remained in the study, 174 (75.0%) cases were male. The mean age was 60.60±9.42 years, and the mean body mass index was 27.15±3.93 kg/m. None of the patients expired during the current admission. The ratio of partial pressure arterial oxygen to the fraction of inspired oxygen (PaO/FiO) 1 hour after admission to the intensive care unit (ICU), before extubation, and at 4 hours after extubation was less than 300 mmHg in 66.6%, 72.2%, and 86.6% of the patients and less than 200 mmHg in 20.8% 17.7%, and 30.2% of the patients, respectively. Among the different variables, only a heavier weight was associated with a PaO/FiO ratio of less than 300 mmHg at 1 hour after ICU admission and at 4 hours after extubation (P=0.001). A rise in the cross-clamp time showed a significant association with the risk of a PaO/FiO ratio of less than 200 mmHg at 4 hours after extubation (P=0.014). This study shows that hypoxemia following CABG is very common in the first 48 postoperative hours, although it is a benign and transient event. The high prevalence may affect the accuracy of the ARDS criteria and their positive or negative predictive value.
急性低氧血症是急性呼吸窘迫综合征（ARDS）的主要特征，而ARDS是冠状动脉旁路移植术（CABG）最严重的并发症之一。鉴于急性低氧血症的数据匮乏，我们试图确定CABG术后患者中急性低氧血症的患病率及其危险因素。这项横断面研究于2012年在德黑兰心脏中心对连续两个月接受体外循环CABG的患者进行。评估了动脉血气变量、年龄、性别、体外循环和夹闭时间、射血分数、肌酐水平以及体重指数对ARDS和急性肺损伤临界值时低氧血症患病率的影响。在总共232名纳入研究的患者中，174例（75.0%）为男性。平均年龄为60.60±9.42岁，平均体重指数为27.15±3.93kg/m²。所有患者在本次住院期间均未死亡。重症监护病房（ICU）入院后1小时、拔管前以及拔管后4小时，患者的动脉血氧分压与吸入氧分数之比（PaO₂/FiO₂）分别有66.6%、72.2%和86.6%的患者低于300mmHg，分别有20.8%、17.7%和30.2%的患者低于200mmHg。在不同变量中，只有体重较重与ICU入院后1小时和拔管后4小时PaO₂/FiO₂比值低于300mmHg相关（P=0.001）。夹闭时间延长与拔管后4小时PaO₂/FiO₂比值低于200mmHg的风险显著相关（P=0.014）。本研究表明，CABG术后低氧血症在术后48小时内非常常见，尽管这是一个良性且短暂的事件。高患病率可能会影响ARDS标准的准确性及其阳性或阴性预测价值。
