Provisional Decision-Making for Perioperative Blood Pressure Management: A Narrative Review

Abstract

Blood pressure (BP) is a basic determinant for organ blood flow supply. Insufficient blood supply will cause tissue hypoxia, provoke cellular oxidative stress, and to some extent lead to organ injury. Perioperative BP is labile and dynamic, and intraoperative hypotension is common. It is unclear whether there is a causal relationship between intraoperative hypotension and organ injury. However, hypotension surely compromises perfusion and causes harm to some extent. Because the harm threshold remains unknown, various guidelines for intraoperative BP management have been proposed. With the pending definitions from robust randomized trials, it is reasonable to consider observational analyses suggesting that mean arterial pressures below 65 mmHg sustained for more than 15 minutes are associated with myocardial and renal injury. Advances in machine learning and artificial intelligence may facilitate the management of hemodynamics globally, including fluid administration, rather than BP alone. The previous mounting studies concentrated on associations between BP targets and adverse complications, whereas few studies were concerned about how to treat and multiple factors for decision-making. Hence, in this narrative review, we discussed the way of BP measurement and current knowledge about baseline BP extracting for surgical patients, highlighted the decision-making process for BP management with a view to providing pragmatic guidance for BP treatment in the clinical settings, and evaluated the merits of an automated blood control system in predicting hypotension.

Figure 1

The physiology of BP and miscellaneous factors affecting organ perfusion. BP is determined by production of CO and SVR. PA: blood flow redistribution and organ-specific RVR influence the organ perfusion. BP: blood pressure; CO: cardiac output; SV: stroke volume; SVR: systemic vascular resistance; PA: pressure autoregulation; RVR: regional vascular resistance.

Figure 2

The flow chart for decision-making for BP targets and hypotension interventions during surgery. The main determinants for BP targets are baseline BP, type of surgery, and specific pathophysiological alterations and weight between organ ischemia and impending surgical bleeding. The BP targets are initial values and a fixed threshold, and maintaining sufficient oxygen supply is priority to a fixed BP value. Individualized BP management highlights the importance of balancing conflicting risks. BP: blood pressure; SBP: systolic blood pressure; DBP: diastolic blood pressure; MAP: mean arterial pressure; and CPB: cardiopulmonary bypass.