低镁血症对重症脓毒症患者预后的影响

Influence of hypomagnesemia on the prognosis of severe septic patients

目的探讨低镁血症对重症脓毒症患者预后的影响。方法采用回顾性研究方法,分析中国科学技术大学附属第一医院重症医学科2016年1月1日至2020年12月21日收治的207例脓毒症患者的临床资料,包括性别、年龄及确诊脓毒症24 h内的实验室指标〔降钙素原(PCT)、C-反应蛋白(CRP)、血乳酸(Lac)、pH值和血镁、血钙、血氯、血磷水平〕;记录患者急性生理学与慢性健康状况评分Ⅱ(APACHEⅡ)、序贯器官衰竭评分(SOFA)及28 d预后;并根据预后分为存活组和死亡组,比较两组临床资料和实验室指标的差异。采用Pearson相关性检验进行临床指标间的相关性分析;采用多因素Logistic回归分析筛选影响预后的危险因素;绘制受试者工作特征曲线(ROC曲线),计算ROC曲线下面积(AUC),评估潜在预后指标。结果207例脓毒症患者中,28 d存活102例,死亡105例,28 d病死率为50.72%。两组性别、年龄、CRP、pH值、血氯和血磷水平差异均无统计学意义;死亡组血镁、血钙水平均明显低于存活组〔血镁(mmol/L):0.68±0.14比0.80±0.12,血钙(mmol/L):1.93±0.21比2.01±0.20,均P<0.01〕,而PCT、Lac、APACHEⅡ评分和SOFA评分均明显高于存活组〔PCT(mg/L):8.32(1.64,55.01)比3.55(0.97,12.31),Lac(mmol/L):2.90(1.70,4.30)比2.10(1.03,3.89),APACHEⅡ评分(分):21.24±6.40比17.42±7.02,SOFA评分(分):9.14±3.55比6.91±3.31,均P<0.01〕。207例患者中,血镁正常(血镁水平为0.75~1.25 mmol/L)96例,低镁血症(血镁水平<0.75 mmol/L)111例;低镁血症组患者28 d病死率明显高于正常血镁组〔61.26%(68/111)比38.54%(37/96),P<0.01〕。Pearson相关性分析显示,脓毒症患者血镁水平与PCT呈显著负相关(r=-0.173,P<0.05),与APACHEⅡ评分呈显著正相关(r=0.159,P<0.05);与CRP、SOFA评分无相关性(r值分别为-0.029、0.091,均P>0.05)。Logistic回归分析显示,血镁、APACHEⅡ评分及SOFA评分是脓毒症患者28 d死亡的独立危险因素〔血镁:优势比(OR)<0.001,95%可信区间(95%CI)为0.000~0.002,P<0.001;APACHEⅡ评分:OR=1.092,95%CI为1.022~1.168,P=0.010;SOFA评分:OR=1.168,95%CI为1.026~1.330,P=0.019〕。ROC曲线分析显示,血镁和APACHEⅡ评分对重症脓毒症患者28 d死亡均有一定预测价值〔AUC及95%CI分别为0.723(0.655~0.791)、0.680(0.607~0.754)〕。当血镁的阈值为0.64 mmol/L时,敏感度为41.0%,特异度为93.1%;当APACHEⅡ评分的阈值为16.50分时,敏感度为78.1%,特异度为55.9%,提示血镁的特异度高于APACHEⅡ评分。结论重症脓毒症患者合并低镁血症时预后较差;血镁水平可作为判断重症脓毒症患者预后的指标。

Objective To investigate the influence of hypomagnesemia on the prognosis of patients with severe sepsis.Methods A retrospective study was conducted.The clinical data of 207 septic patients admitted to the department of critical care medicine of the First Affiliated Hospital of University of Science and Technology of China from January 1,2016 to December 21,2020 were analyzed,including gender,age and laboratory indicators within 24 hours after sepsis diagnosis[procalcitonin(PCT),C-reactive protein(CRP),blood lactic acid(Lac),pH value and blood magnesium,calcium,chlorine and phosphorus levels].The acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ )score,sequential organ failure assessment(SOFA)score and 28-day prognosis were collected.The patients were divided into survival group and non-survival group according to the prognosis,and the clinical data and laboratory indexes were compared between the two groups.Pearson correlation test was used to analyze the correlation between clinical indicators.Multivariate Logistic regression analysis was used to screen the risk factors affecting the prognosis.The receiver operator characteristic curve(ROC curve)was drawn,and the area under ROC curve(AUC)was calculated to evaluate the potential prognostic indicators.Results Among the 207 septic patients,102 survived and 105 died on the 28th day,and the 28-day mortality was 50.72%.There were no significant differences in gender,age,CRP,pH value,blood chlorine or blood phosphorus levels between the two groups.The blood magnesium and blood calcium levels in the non-survival group were significantly lower than those in the survival group[blood magnesium(mmol/L):0.68±0.14 vs.0.80±0.12,blood calcium(mmol/L):1.93±0.21 vs.2.01±0.20,both P<0.01],and PCT,Lac,APACHE Ⅱ score and SOFA score were significantly higher than those in the survival group[PCT(mg/L):8.32(1.64,55.01)vs.3.55(0.97,12.31),Lac(mmol/L):2.90(1.70,4.30)vs.2.10(1.03,3.89),APACHE Ⅱ score:21.24±6.40 vs.17.42±7.02,SOFA score:9.14±3.55 vs.6.91±3.31,all P<0.01].Among the 207 patients,96 patients had normal blood magnesium level(0.75-1.25 mmol/L)and 111 patients had hypomagnesemia(<0.75 mmol/L).The 28-day mortality of septic patients in the hypomagnesemia group was significantly higher than that in the normal magnesium group[61.26%(68/111)vs.38.54%(37/96),P<0.01].Pearson correlation analysis showed that the blood magnesium level of sepsis patients was negatively correlated with PCT(r=-0.173,P<0.05),and it was positively correlated with APACHE Ⅱ score(r=0.159,P<0.05),but it had no correlation with CRP or SOFA score(r values were-0.029 and 0.091,both P>0.05).Logistic regression analysis showed that serum magnesium,APACHE Ⅱ score and SOFA score were independent risk factors for 28-day death in patients with sepsis[serum magnesium:odds ratio(OR)<0.001,95%confidence interval(95%CI)was 0.000-0.002,P<0.001;APACHE Ⅱ score:OR=1.092,95%CI was 1.022-1.168,P=0.010;SOFA score:OR=1.168,95%CI was 1.026-1.330,P=0.019].ROC curve analysis showed that blood magnesium and APACHE Ⅱ score had a certain predictive value for 28-day mortality in patients with severe sepsis[AUC(95%CI)was 0.723(0.655-0.791)and 0.680(0.607-0.754),respectively].When the blood magnesium threshold was 0.64 mmol/L,the sensitivity was 41.0%and the specificity was 93.1%.When APACHE Ⅱ score threshold was 16.50,the sensitivity was 78.1%and the specificity was 55.9%indicating that the specificity of serum magnesium was higher than that of APACHE Ⅱ score.Conclusions Severe septic patients complicated with hypomagnesemia have a poor prognosis.Serum magnesium level can be used as a prognostic indicator for severe septic patients.