Inpatient Pediatric Blood Pressure Monitoring: Upper vs Lower Extremity Measurements

Guidance for interpreting and measuring blood pressure (BP) in pediatrics was published in the guidelines by Flynn et al in 2017 and recommends upper extremity BP measurements.1 Anecdotally, it is common for BPs to be measured in the lower extremities in the hospital. Previous studies have investigated the measurement of lower extremity BPs in pediatric patients of a variety of ages.2–9 The studies often had contradictory findings, and none were focused on inpatient pediatric patients. This study aimed to describe the frequency with which lower extremity BP measurements occur in the inpatient pediatric population. A secondary goal of the study was to investigate whether there were differences in BPs when measured in the upper and lower extremities. We hypothesized that lower extremity BP measurements happen frequently in pediatric hospitals, and lower extremity systolic BPs (SBPs) would be higher on average than upper extremity BPs. We aimed for this study to serve as a basis for future studies and quality improvement projects, particularly a prospective, matched study to investigate BP differences based on which extremity is measured.This study was a retrospective cross-sectional study of pediatric patients admitted to a tertiary care referral hospital in 2022. This institutional review board–approved study included admitted patients aged 30 days to 18 years who did not require intensive care. Exclusion criteria are listed in the Supplemental Material. Patient demographics were summarized by sex, race/ethnicity, insurance type, and BP site, overall and stratified by age group (aged 30 days to 3 years, aged 4 to 10 years, and aged 11 to 18 years). Unadjusted and adjusted differences in SBP, diastolic BP, heart rate, and temperature between lower and upper BP sites were calculated. Adjusted differences were estimated using a hierarchical mixed effects model using age group, race/ethnicity, insurance type, heart rate, and temperature as covariates. Statistical analysis was completed using IBM SPSS Statistics for Windows, Version 2024In total, there were 286 754 BP measurements (Table 1) included in the study, with 36.4% of BP measurements occurring in the lower limb compared with 50.4% in the upper extremity. In patients aged less than 4 years, lower extremity BPs were more frequently measured than upper extremity BPs (Table 1). For infants aged less than 1 year, 74.2% of BP measurements were conducted in the lower extremities. After age 4 years, the number of lower extremity BP measurements as a proportion of total BP measurements drops. When adjusted, SBP and diastolic BP in the lower extremity were 8.6 and 3.4 mm Hg higher on average than upper extremity measurements, respectively (Table 2).This study demonstrates that lower extremity BP measurement is common in the inpatient setting, particularly in younger patients. Lower extremity BP measurements did occur in a small percentage of adolescents as well, which could be attributed to patients’ medical complexity or limited ability to check upper extremity pressures. We found that at a population level, average BP is higher in the lower extremities than upper extremities. As a result, it is important for clinicians to make note of the location of BP measurements when making clinical decisions. We had several limitations. First, this was a retrospective study that looked at BP measurements in different patients admitted with different clinical conditions, and there are likely unconsidered confounding variables. Second, we could not ensure that BP measurements were correctly performed as recommended by the guidelines by Flynn et al.1 However, as a large academic tertiary referral hospital, it is likely that our BP measurement practice is like other similar institutions. Lastly, a considerable number of measurements had to be excluded from the analysis, as no BP measurement site was documented. In the future, it will be helpful to describe the state of pediatric BP monitoring at other hospitals to see if similar findings are present in other settings. A future study that simultaneously measures 4 extremity BPs in pediatric inpatients is needed to confirm whether SBP measurements are higher in lower extremities. Quality improvement projects should be developed to improve the frequency with which upper extremity BP measurements follow national guidelines. This study contributes to the existing literature by characterizing inpatient pediatric BP monitoring practices, specifically the frequency of upper vs lower extremity measurement, an area previously understudied.