Comparison of Central and Peripheral Arterial Blood Pressure Gradients in Critically Ill Patients: A Systematic Review and Meta-Analysis.

Objectives: Measurement of blood pressure taken from different anatomical sites, are often perceived as interchangeable, despite them representing different parts of the systemic circulation. We aimed to perform a systematic review and meta-analysis on blood pressure differences between central and peripheral arterial cannulation in critically ill patients.

Data sources: We searched MEDLINE, Cochrane Central Register of Controlled Trials, and Embase from inception to December 26, 2023, using Medical Subject Headings (MeSH) terms and keywords.

Study selection: Observation study of adult patients in ICUs and operating rooms who underwent simultaneous central (femoral, axillary, or subclavian artery) and peripheral (radial, brachial, or dorsalis pedis artery) arterial catheter placement in ICUs and operating rooms.

Data extraction: We screened and extracted studies independently and in duplicate. We assessed risk of bias using the revised Quality Assessment for Studies of Diagnostic Accuracy tool.

Data synthesis: Twenty-four studies that enrolled 1598 patients in total were included. Central pressures (mean arterial pressure [MAP] and systolic blood pressure [SBP]) were found to be significantly higher than their peripheral counterparts, with mean gradients of 3.5 and 8.0 mm Hg, respectively. However, there was no statistically significant difference in central or peripheral diastolic blood pressure (DBP). Subgroup analysis further highlighted a higher MAP gradient during the on-cardiopulmonary bypass stage of cardiac surgery, reperfusion stage of liver transplant, and in nonsurgical critically ill patients. SBP or DBP gradient did not demonstrate any subgroup specific changes.

Conclusions: SBP and MAP obtained by central arterial cannulation were higher than peripheral arterial cannulation; however, clinical implication of a difference of 8.0 mm Hg in SBP and 3.5 mm Hg in MAP remains unclear. Our current clinical practices preferring peripheral arterial lines need not change.