The accuracy of blood pressure measured by arterial line and non-invasive cuff in critically ill children

Abstract

BackgroundThe accuracy of arterial lines (AL) using the flush test or stopcock test has not been described in children, nor has the difference between invasive arterial blood pressure (IABP) versus non-invasive cuff (NIBP) blood pressure.MethodsAfter ethics approval and consent, we performed the flush test and stopcock test on AL (to determine over damping, under damping, and optimal damping), and determined the difference (NIBP–IABP) in systolic, diastolic, and mean blood pressure (ΔSBP, ΔDBP, and ΔMAP). The primary outcome was incidence (95 % CI) of optimally damped AL. Predictors of ΔBP (effect size (95 % CI)) were determined using multiple linear regression.ResultsThere were 147 AL tests in 100 enrolled patients with mean age 44.7 (SD 56) months, weight 16.8 (SD 18.3) kg, male 59 %, postoperative-cardiovascular 52 %, peripheral-AL 78 %, inotropes 29 %, vasodilators 15 %, and ventilated 73 %. The flush test performed in 66 patients (45 %) showed optimal damping in 30 (46 %; 95 % CI 34, 57 %), over damping in 25 (38 %) and under damping in 11 patients (17 %). The stopcock test was over-damped in 128/146 patients (88 %), with the same damping as the flush test in 24/64 (38 %). In optimally damped (flush test) AL, ΔSBP, ΔDBP, and ΔMAP were 0.8 (SD 12.2), −5.2 (SD 8.7), and −4.9 (7.6) respectively. A second set of AL tests was done 2 h later on the same day in 62 patients; AL damping often changed (10/28 flush tests) and ΔBPs correlated poorly (r = 0.31–0.55). Predictors (effect size) of ΔDBP were vasodilator infusion (15.6 (2.9 to 28.3); p = 0.016) and optimal damping (−7.2 (−12.2 to 2.2); p = 0.005); and of ΔMAP were vasodilator infusion (10.0 (−0.3 to 20.4); p = 0.057) and optimal damping (−4.0 (−8 to 0.1); p = 0.058). There were no independent predictors of damping category (n = 66 flush tests).ConclusionsOptimally damped AL occur in half of critically ill children, and this is not predictable. There is much variability in ∆BP between NIBP and the gold standard IABP, and this varies even in the same patient on the same day, and is not easily predictable. In critically ill children, NIBP may not be accurate enough to guide management, and more attention to ensuring the AL is optimally damped is needed.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-016-1354-x) contains supplementary material, which is available to authorized users.

Closed-Loop– and Decision-Assist–Guided Fluid Therapy of Human Hemorrhage*

“…There is, however, ample evidence suggesting that non-invasively measured MAP is a better indicator of invasive blood pressure than non-invasive systolic blood pressure alone (45–47). While to solve this partial discrepancy is beyond the scope of this study, it has been shown recently that the difference of NIBP and invasive arterial blood pressure is clinically negligible in both adults and children with few exceptions (48,49); NIBP continues to be widely used by ICU physicians (50), and NIBP is proportional to intravascular volume during hemorrhage (12). It is furthermore readily and feasibly available to professionals of all levels of experience and causes few complications (51).…”

Risk of over-diagnosis of hypotension in children: a comparative analysis of over 50,000 blood pressure measurements

“…Maintaining a 'normal' blood pressure (BP) and avoiding hypotension are key goals in critically-ill children [1]. Invasive arterial blood pressure (IABP) and non-invasive oscillometric blood pressure (NIBP) measurements are typically used interchangeably despite reports of bias and lack of precision [2][3][4][5].…”

Nutritional Management of Patients With Enterocutaneous Fistulas: Practice and Progression

“…“If the gut works, use it or prepare to lose it ( 38 ).” In critically ill surgical patients, EN may have considerable advantages over PN. Compared with PN, EN is considered to improve intestinal barrier function, reduce the incidence of infection complications in critically ill patients, and maintain immune function ( 25 , 39 , 40 ). EN was identified as an independent factor associated with fistula closure ( 41 ).…”