[Interest of the noninvasive techniques for the measurement of the blood pressure in critical care]

ABSTRACT

The goal of this study is to compare three techniues for the measurement of artrial blood pressure [invesive [I], osecillometric [O], and sphygmomanometric [S] in critically ill patients to determin if the noninvasive techniques can replace the arterial catheterization, and to see whether the relation between these three methods varies over time. Thiyty-three patients were recruited in the medical critial care unit at Hotel-Dieu de France hospital. Each patients included had an arterial catheter inserted in the right femoral artery. The cuff of the oscillometer was positioned on the level of the right arm and measurements by sphygmomanometric technique were carried out on the level of the left arm. All measurements were taken at the same time, three times per day, during the patients stay in the critical care unit. The study period was five days with an overall of fifteen measurements for each technique. At to, the calculation of the corelation coefficients of Spearman showed a very good correlation between the three measurements techniques for systolic [I/O r=0.7258, p< 0.001; I/S r= 0.8824, p< 0.001; O/S r=0.8675, p< 0.001], diastolic [I/O r=0.7620, p< 0.001; I/S r=0.7910, p< 0.001; O/S r=0.7152, p< 0.001] and mean [I/O r=0.7725, p<0.001; I/S r=0.8221, p< 0.001 ; O/S r=0.8363, p< 0.001]. Pressures between t1 and t15, analyis of variance [ANOVA] showed that the three methods remained well correlated [systolic p=0.175; diastolic p=0.107; mean p=0.550]. The calculation of the limits of agreement between the three techniques showed a lack of agreement between the invasive technique and the sphygmomanometric technique in 25% of the cases, and a good agreetment between invasive and oscillometric techiques in 87.5% of the cases. Oscillometry can replace the direct intra-arterial standard technique for the monitoring of the blood pressure in the intensive care unit. In contrast, the sphygmomanometry in the ICU gives inaccurate results that could lead to inappropriate therapeutic attitudes