Clinical significance of point-of-care testing of N-terminal pro-brain natriuretic peptide in pregnant patients complicated by hypertensive disorders / 中华危重病急救医学

ABSTRACT

Objective To observe the features of the changes in the whole blood N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in pregnant patients with complication of hypertensive disorders,its correlation to the severity of the illness,and to investigate the diagnostic value of point-of-care testing of NT-proBNP in patients with hypertensive disorders complicating pregnancy.Methods A prospective observation was conducted.Sixty-nine patients with hypertensive disorders complicating pregnancy admitted to Department of Critical Care Medicine of Liaocheng People's Hospital in Shandong Province from April 2013 to April 2015 were enrolled.All patients were divided into gestational hypertension group (n =16),preeclampsia group (n =30) and eclampsia group (n =23).At the same time,30 age-matched normal pregnant women were enrolled as the control group.The acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score of all patients with hypertensive disorders complicating pregnancy were calculated within 24 hours after intensive care unit (ICU) admission.NT-proBNP in venous blood at 1,3,5 days after ICU admission was determined with point-of-care testing,in order to analyze the correlation of changes in NT-proBNP value in each group and the severity of the disorder.Receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of NT-proBNP in the whole blood in hypertensive disorder complicating pregnancy.Results The APACHE Ⅱ score of the eclampsia group was significantly higher than that of the preeclampsia group,and it was higher than that of gestational hypertension group (15.91 ± 1.06,13.73 ± 1.09,10.31 ± 1.10,all P ＜ 0.01).The NT-proBNP in normal pregnancy group was lower than 125.00 ng/L,with a mean of 90.00 (79.75,100.00) ng/L.With the aggravation of the disease,NT-proBNP was gradually increased.On the first day in ICU,the NT-proBNP of the eclampsia gronp was significantly higher than that of the preeclampsia group,and it was higher in preeclampsia group than that of gestational hypertension group [ng/L1960.00 (1 226.00,3 229.00),859.50 (626.75,2439.00),505.00 (171.25,604.05),P ＜ 0.05 or P ＜ 0.01].With the extension of duration of treatment,the levels of NT-proBNP (ng/L) in the eclampsia group,preeclampsia group,and gestational hypertension group was gradually decreased,and had a statistically significant difference on the fifth day as compared with that of the first day [310.00 (210.00,430.00) vs.1 960.00 (1 226.00,3 229.00) in eclampsia group,265.00 (229.50,333.25) vs.859.50 (626.75,2439.00) in preeclampsia group,and 203.00 (115.50,259.25) vs.505.00 (171.25,604.05) in gestational hypertension group,all P ＜ 0.01].APACHE Ⅱ score of the patient with hypertensive disorders complicating pregnancy was positively correlated with the level of NT-proBNP on the first day in ICU (r =0.795,P =0.000).It was shown by ROC curve analysis that the area under the ROC curve (AUC) of NT-proBNP in the whole blood for the diagnosis of the patient with hypertensive disorder complicating pregnancy was 0.986 [95％ confidence interval (95％C/) =0.753-0.924].When the cutoff value was 122.50 ng/L,the sensitivity was 97.1％,and the specificity was 100.0％.No patient died,all the 69 patients recovered and discharged.Conclusions The levels of NT-proBNP in the whole blood in the patients with hypertensive disorder complicating pregnancy,especially those with eclampsia,were significantly higher,and it was correlated with the severity of illness.After treatment,the levels were gradually lowered with the improvement of the disease.Therefore,it is concluded that the point-of-care testing of NT-proBNP in the whole blood has an excellent value for the diagnosis and evaluation of hypertensive disorder complication pregnancy.