重症患者离子钙水平对预后的影响

目的 探讨重症监护病房(ICU)重症患者钙代谢异常的发生情况以及离子钙水平对预后的影响.方法 采用单中心前瞻性观察性研究,选择2013年1月至2015年1月入住无锡市人民医院综合性ICU的重症患者进行筛选,所有入选的患者入ICU后24h内血标本送检,测离子钙水平记为iCa,按iCa水平进行分组:iCa＜ 1.15 mmol/L纳入低iCa组;iCa＞ 1.25 mmol/L纳入高iCa组;1.15 mmol/L≤iCa≤1.25 mmol/L纳入正常iCa组.统计患者的性别、年龄、手术史、既往病史、人ICU诊断、机械通气时间、ICU住院时间以及转归等信息并计算入ICU24 h内的序贯器官衰竭评分(SOFA)和急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分.采用Logistic回归分析筛选重症患者死亡的危险因素;采用Kaplan-Meier生存分析,按iCa水平分层,绘制14 d生存曲线,采用log-rank检验比较低iCa组和正常iCa组的累计生存率.结果 共纳入重症患者368例,其中正常iCa组117例,低iCa组247例,高iCa组4例.正常iCa组以神经系统病变最多见(21.37％),低iCa组以脓毒症最多见(21.46％),高iCa组以肿瘤患者最多见(50％).低iCa组脓毒症患者(21.46％)多于正常iCa组(10.26％),高iCa组无脓毒症患者,组间差异具有统计学意义(P =0.021).正常iCa组肿瘤患者(1.71％)明显少于高iCa组(50％)和低iCa组(8.1％),差异具有统计学意义(P =0.002).低iCa组较正常iCa组有更多患者合并慢性肾功能不全(P=0.042).两组性别、年龄、血钠、血钾、血氯水平、APACHEⅡ评分差异无统计学意义(P＞0.05),但低iCa组SOFA评分(P=0.039)和14 d病死率(P =0.035)更高,机械通气时间(P =0.049)和ICU住院天数(P =0.012)也更长.根据多因素Logistic回归分析显示,iCa水平(OR=2.352,95％ CI:1.039 ～4.023,P=0.041)和APACHEⅡ评分(OR=1.214,95％ CI:1.067～1.285,P=0.002)为影响ICU重症患者14 d内死亡的独立危险因素.按iCa水平分层绘制Kaplan-Meier生存曲线,低iCa组14 d累计生存率显著低于正常iCa组,差异有统计学意义(P =0.037).结论 离子钙水平与ICU重症患者病死率密切相关,临床应重视重症患者低钙血症的发生.

The influence of ionized calcium on the prognosis of critically ill patients

Objective To investigate the incidence of ionized hypocalcemia and the effect of ionized calcium (iCa) on the prognosis of critically ill patients in intensive care unit (ICU).Methods Adult patients admitted to ICU from January 2013 to January 2015 were enrolled for prospective observation.Patients were selected to exclude the ineligible ones.All selected patients were monitored for iCa levels within 24 hours after ICU admission,and they were divided into three groups:normo-iCa group (iCa levels ＜ 1.15mmol/L),hypo-iCa group (1.15 mmol/L≤ iCa levels ≤1.25 mmol/L),hyper-iCa group (iCa ＞ 1.25 mmol/L).Enormous data from every patient including demographics,past history about disease contracted and surgical intervention,laboratory findings,duration of mechanical ventilation,length of ICU stay and outcomes were recorded.The acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score and sequential organ failure assessment (SOFA) score during the first 24 hours after ICU admission were calculated.The risk factors for the death in critically ill patients were postulated by logistic regression analysis.Kaplan-Meier survival estimator was used to draw the 14-day survival curve,and the survival rate was compared between normo-iCa group and hypo-iCa group by log-rank test.Results A total of 368 critically ill patients were enrolled and 117 of them were classified into normo-iCa group,247 into hypo-iCa group,and 4 into hyper-iCa group.As to the nature of various diseases giving different kinds of biochemical impacts on patients,patients in normo-iCa group were mainly consisted of patients with nervous system diseases (21.37％),hypo-iCa group patients were dominant in patients with sepsis (21.46％),and hyper-iCa was often found in patients with tumor (50％).The proportion of patients with sepsis was significantly greater in the hypo-iCa group (21.46％) compared with that of normo-iCa group (10.26％),and there was no sepsis patient found in hyper-iCa group,and there were statistically significant differences in iCa among the three groups (P =0.021).The proportion of patients with tumor was significantly lower in the normo-iCa group (1.71％) compared with that of hypo-iCa group (8.1％) and hyper-iCa group (50％),and there were statistically significant differences among the three groups (P =0.002).There were more patients with chronic renal failure in hypo-iCa group than those in normo-iCa group (P =0.042).Compared with the normo-iCa group,the patients of hypo-iCa group were found to have higher SOFA scores (P =0.039),longer duration of mechanical ventilation (P =0.049),longer ICU stay (P =0.012) and higher mortality (P =0.035),but no statistically significant differences in gender,age,levels of other electrolytes (natrium,potassium,chlorine),and APACHE Ⅱ score between two groups (P＞0.05).As shown in the result of the multivariate logistic regression analysis,iCa level (OR =2.352,95％ CI:1.039-4.023,P =0.041) and APACHE Ⅱ score (OR =1.214,95％ CI:1.067 ～ 1.285,P =0.002) were independent risk factors for death in critically ill patients.The 14-day accumulative survival rate in hypo-iCa group was significantly lower than that in normo-iCa group (P =0.037).Conclusions The iCa levels are closely related to mortality rate in patients in ICU,and it is worthwhile to pay more attention to the occurrence of ionized hypocalcemia in critically ill patients.