Novel targeted hemodynamic therapies are needed.

Current guidelines and consensus statements acknowledge the potential value of personalizing perioperative hemodynamic treatments, advocating for maintaining intraoperative MAPs within 20% of baseline. [6]

This practice, primarily based on physiologic rationale (i.e. the blood pressures patients tolerate preoperatively should also be tolerated intraoperatively), is supported by one trial (INPRESS) which investigated this strategy 298 patients predominantly undergoing abdominal surgery and found a reduction in the risk of postoperative organ dysfunction. [10] This treatment effect was driven primarily by reductions in the incidence of postoperative acute kidney injury and altered consciousness. These promising findings have given rise to subsequent trials further investigating this hemodynamic management strategy. [11] Data from IMPROVE-multi will certainly further inform the practice of targeting preoperative BPs during surgery.

However, the strategy of targeting preoperative BPs has important limitations. First, it is unclear how “baseline” BP should be determined, i.e. whether and how ambulatory 24h-BP measurements should be used to estimate the safe BP range during surgery. Second, it remains to be established how a strategy of obtaining 24h-BP measurements could be implemented in clinical practice, particularly in emergent settings, i.e. in the patients at the highest risk of postoperative complications and hence most in need of targeted hemodynamic management. Third and most importantly, the assumption that preoperative BPs should be safe intraoperatively may not be valid. Preliminary data from AUTOREGULATE-NONCARDIAC suggest that in a subset of patients, preoperatively tolerated BPs fall outside of cerebral autoregulatory boundaries, i.e. outside of the safe BP range for the brain. [12] These findings are consistent with data from cardiac surgery showing that preoperative BPs do not predict cerebral autoregulatory boundaries during cardiopulmonary bypass. [13] Finally, the adequacy of blood pressure in the perioperative setting is highly context-specific, i.e. the same BP could be both sufficient and insufficient at different phases of an operation when anesthestic and surgical factors can dynamically affect vital organ perfusion. [12]

Taken together, these factors underline the need for novel targeted hemodynamic therapies in the perioperative setting.