Comparison of non-invasive vs invasive blood pressure measurement in neonates undergoing therapeutic hypothermia for hypoxic ischemic encephalopathy

Comparison of intraoperative blood pressure values measured by noninvasive versus invasive methods during normotension, hypertension, and hypotension

Background and Aims

Monitoring of intraoperative blood pressure (BP) is essential. We aimed to compare BP values simultaneously recorded by invasive and noninvasive methods under general anesthesia (GA) during normotension, hypertension, and hypotension. Mean arterial pressure (MAP) values calculated by the automated technique were also compared to the values obtained using predefined formula.

Material and Methods

An observational, prospective study was conducted in 250 adult patients undergoing elective surgeries under GA. Before induction, noninvasive blood pressure (NIBP) was measured in the arm in a supine position using an automated oscillometer. Radial artery in the opposite arm was cannulated. NIBP and arterial BP (ABP) were recorded simultaneously during normotension, hypotension, and hypertension.

Results

During normotension and hypertension, systolic BP (SBP) measured by NIBP and ABP were comparable. Diastolic BP (DBP) and MAP during normotension were significantly higher with NIBP (73.65 ± 7.73 vs. 65.69 ± 8.39 and 87.79 ± 8.43 vs. 84.24 ± 8.82, respectively). During hypertension, DBP and MAP were significantly higher with NIBP (90.44 ± 11.61 vs. 78.59 ± 11.09 and 111.67 ± 10.43 vs. 105.63 ± 11.06, respectively). During hypotension, SBP was significantly higher in ABP (91.14 ± 6.90 vs. 86.24 ± 6.06), and DBP and MAP were comparable. Comparison of MAP measured by ABP and NIBP techniques with the MAP calculated using predefined formula in normotension showed significantly higher values with the automated technique.

Conclusions

During normotension and hypertension, DBP and MAP showed significantly higher values with the NIBP technique compared to ABP, with comparable SBP values. During hypotension, SBP showed significantly higher values with the ABP technique, with comparable DBP and MAP. MAP obtained using predefined formula and automated method in normotension was significantly higher with the automated technique.

Blood pressure monitoring following kidney transplantation in children: a comparison of invasive and noninvasive measurements using Doppler as a benchmark technique

BACKGROUND

Blood pressure (BP) monitoring following pediatric kidney transplantation is essential for optimizing graft perfusion. Differences between invasive BP and noninvasive BP (NIBP) measurements are sometimes considerable. We aimed to assess agreement between invasive BP and NIBP in pediatric patients after kidney transplantation and compare with measurements obtained by systolic Doppler with manual sphygmomanometer as a reference technique.

METHODS

A prospective, observational cohort study, of children aged 18 years or younger, admitted immediately following kidney transplantation to the pediatric intensive care unit of a tertiary, university-affiliated medical center, between May 2019 and June 2021.

RESULTS

Eighty-two paired simultaneous measurements of invasive BP, NIBP, and Doppler BP in 18 patients were compared. Patients were significantly hypertensive, with mean systolic NIBP above the 95th percentile (96 ± 6%). Systolic invasive BP measurements were significantly higher than NIBP (149 ± 20 vs. 136 ± 15 mmHg, p < 0.001). Substantial differences (≥ 20 mmHg) were found in 23% (95% CI 15-34%). Similar disagreement was found between systolic invasive and Doppler BP (150 ± 23 and 137 ± 17 mmHg, respectively, p < 0.001). In contrast, systolic NIBP was in good agreement with Doppler BP (135 ± 17 and 138 ± 18, respectively, p = 0.27). A moderate to strong correlation was found between higher systolic invasive BP and the difference to systolic Doppler BP (Spearman's ρ = 0.63, p < 0.001).

CONCLUSIONS

In children immediately following kidney transplantation, clinically significant disagreement was found between invasive and noninvasive BP measurements. Invasive BP values were significantly higher than those obtained by Doppler. Better agreement was found between NIBP and Doppler. These issues should be considered when interpreting BP measurements in this sensitive patient population. A higher resolution version of the Graphical abstract is available as Supplementary information.

Neonatal Blood Pressure Standards: What Is "Normal"?

Blood pressure (BP) is routinely measured in newborn infants. Published BP nomograms demonstrate a rise in BP following delivery in healthy infants at all gestational ages (GA) and evidence that BP values are higher with increasing birth weight and GA. However, the complex physiology that occurs in newborn infants and range of BP values observed at all GA make it difficult to identify "normal" BP for a specific infant at a specific time under specific conditions. As such, complete hemodynamic assessment should include the physical examination, perinatal history, other vital signs, and laboratory values in addition to BP values.

Method of Blood Pressure Measurement in Neonates and Infants: A Systematic Review and Analysis

OBJECTIVES

To determine the recommended blood pressure (BP) measurement methods in neonates after systematically analyzing the literature regarding proper BP cuff size and measurement location and method.

STUDY DESIGN

A literature search was conducted in MEDLINE, PubMed, Embase, Cochrane Library, and CINAHL from 1946 to 2017 on BP in neonates <3 months of age (PROSPERO ID CRD42018092886). Study data were extracted and analyzed with separate analysis of Bland-Altman studies comparing measurement methods.

RESULTS

Of 3587 nonduplicate publications identified, 34 were appropriate for inclusion in the analysis. Four studies evaluating BP cuff size support a recommendation for a cuff width to arm circumference ratio of approximately 0.5. Studies investigating measurement location identified the upper arm as the most accurate and least variable location for oscillometric BP measurement. Analysis of studies using Bland-Altman methods for comparison of intra-arterial to oscillometric BP measurement show that the 2 methods correlate best for mean arterial pressure, whereas systolic BP by the oscillometric method tends to overestimate intra-arterial systolic BP. Compared with intra-arterial methods, systolic BP, diastolic BP, and mean arterial pressure by oscillometric methods are less accurate and precise, especially in neonates with a mean arterial pressure <30 mm Hg.

CONCLUSIONS

Proper BP measurement is critical in neonates with naturally lower BP and attention to BP cuff size, location, and method of measurement are essential. With decreasing use of intra-arterial catheters for long-term BP monitoring in neonates, further studies are urgently needed to validate and develop oscillometric methodology with enhanced accuracy.