Department of Emergency Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
Department of Emergency Medicine, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang, Republic of Korea.
Am J Emerg Med. 2022 Jan;51:156-162. doi: 10.1016/j.ajem.2021.10.027. Epub 2021 Oct 23.
The poisoning severity score (PSS) was developed to grade the severity of various types of poisoning. However, in its current form, it requires investigating many variables, some of which have been found not to be associated with carbon monoxide (CO) poisoning severity. Therefore, in this study, we modified the PSS for CO poisoning and compared its usefulness to that of the original PSS, as an early prognostic factor of short-term outcome in CO poisoning patients.
This was a retrospective observational study conducted in patients with CO poisoning who visited the emergency department between January 2014 and December 2020. Patients' primary outcome was their Cerebral Performance Category (CPC) scale score at discharge, which classified those with CPC 1-2 as having a favorable outcome and those with CPC 3-5 as having a poor outcome. We calculated the patients' PSS and their CO-modified PSS by replacing blood and metabolic balance category in the original PSS with carboxyhemoglobin (COHb) and lactate levels, respectively.
This study included 891 patients, of which 852 (95.6%) and 39 (4.4%) were classified into the favorable and poor outcome groups, respectively. Using multivariate analysis, the PSS (odds ratio [OR], 22.961; 95% confidence interval [CI], 10.641-49.546; p < 0.001) and CO-modified PSS (OR, 28.856; 95% CI, 12.874-64.679; p < 0.001) were both found to be associated with poor outcomes at hospital discharge. The areas under the receiver operating characteristic curves for the PSS and CO-modified PSS were 0.874 (95% CI, 0.850-0.895) and 0.881 (95% CI, 0.858-0.901), respectively.
The CO-modified PSS, with fewer variables than the original PSS, was not inferior to predict poor outcomes, and if COHb level is considered together with other parameters, then it can be used both for predicting prognosis and in diagnosis.
中毒严重程度评分（PSS）旨在对各种类型中毒的严重程度进行分级。然而，目前它需要调查许多变量，其中一些变量与一氧化碳（CO）中毒的严重程度无关。因此，在这项研究中，我们对 CO 中毒的 PSS 进行了修改，并将其作为 CO 中毒患者短期预后的早期预测因素，与原始 PSS 的有用性进行了比较。
这是一项回顾性观察性研究，纳入 2014 年 1 月至 2020 年 12 月期间在急诊科就诊的 CO 中毒患者。患者的主要结局是出院时的 Cerebral Performance Category（CPC）评分，将 CPC 1-2 评为预后良好，将 CPC 3-5 评为预后不良。我们通过用碳氧血红蛋白（COHb）和乳酸水平分别替代原始 PSS 中的血液和代谢平衡类别，计算患者的 PSS 和 CO 修正的 PSS。
本研究纳入 891 例患者，其中 852 例（95.6%）和 39 例（4.4%）分别归类为预后良好和不良组。多变量分析显示，PSS（比值比 [OR]，22.961；95%置信区间 [CI]，10.641-49.546；p<0.001）和 CO 修正的 PSS（OR，28.856；95% CI，12.874-64.679；p<0.001）与出院时的不良结局均相关。PSS 和 CO 修正的 PSS 的受试者工作特征曲线下面积分别为 0.874（95% CI，0.850-0.895）和 0.881（95% CI，0.858-0.901）。
与原始 PSS 相比，变量更少的 CO 修正 PSS 并不劣于预测不良结局，如果将 COHb 水平与其他参数一起考虑，则既可以用于预测预后，也可以用于诊断。
