Perioperative Quality Initiative (POQI) consensus statement on the physiology of blood pressure control as applied to perioperative medicine.

Abstract

Background: A multi-disciplinary, international working subgroup of the Third Perioperative Quality Initiative (POQI) consensus meeting reviewed the (patho)physiology and measurement of arterial blood pressure (ABP), as applied to perioperative medicine. Methods: We addressed predefined questions by undertaking a modified Delphi analysis, in which primary clinical research and review articles were identified using MEDLINE. Strength of recommendations, where applicable, were graded by NICE guidelines. Results: Perioperative ABP management is a physiologically-complex challenge influenced by multiple factors: (i) ABP is the input pressure to organ blood flow, but is not the sole determinant of perfusion pressure; (ii) blood flow is often independent of changes in perfusion pressure, due to autoregulatory changes in vascular resistance; (iii) microvascular dysfunction uncouples microvascular blood flow from ABP (haemodynamic incoherence) From a practical clinical perspective, we identified that: (i) ambulatory measurement is the optimal method to establish baseline ABP; (ii) automated and invasive ABP measurements have inherent physiological and technical limitations; (iii) individualised ABP targets may change over time, especially during the perioperative period. There remains a need for research in non-invasive, continuous arterial pressure measurements, macro- and microcirculatory control, regional perfusion pressure measurement and the development of sensitive, specific and continuous measures of cellular function to evaluate blood pressure management in a physiologically coherent manner. Conclusion: The multivariable, complex physiology contributing to dynamic changes in perioperative ABP may be underappreciated clinically. The frequently unrecognised dissociation between ABP, organ blood flow, microvascular and cellular function requires further research that develops a more refined, contextualized clinical approach to this routine measurement.