Blood pressure management: myths, studies, and science 

Despite advances in surgical techniques, rates of major complications and mortality in the first weeks following surgery remain alarmingly high. (1) Postoperative deaths are frequently the result of complications that arise after surgery, occurring in up to a quarter of patients who undergo in-patient procedures. (2) Identifying and addressing modifiable risk factors leading to these complications is essential for improving surgical outcomes. One such risk factor is intraoperative hypotension (IOH), which is defined as abnormally low blood pressure during surgery. Observational studies consistently link IOH with being a leading contributor to adverse postoperative outcomes, including acute kidney injury (AKI), myocardial injury after non-cardiac surgery (MINS), stroke, and death. (3)(4) These studies demonstrate that the depth and duration of hypotension are associated with higher risks of postoperative complications, and safe MAP thresholds are not true for all patients. They also show that preoperative blood pressure measurements offer no clear indication of risk, and tailored anaesthetic management of intraoperative pressures may be vital to increase the chance of successful outcomes. (5) While intraoperative hypotension is consistently associated with harm in observational data, this does not confirm causation. Patients who become hypotensive during surgery may be sicker, undergoing higher-risk procedures, or more vulnerable, confounders that are extraordinarily difficult to eliminate without randomised trials. (6) 

In the spotlight session “Blood pressure management: myths, studies and science”, the speakers will analyse the rationale, design, and results of two large, randomised trials on blood pressure management in patients undergoing non-cardiac surgery. They will also cover important ongoing trials on targeted blood pressure management. 

Prof. Bernd Saugel, Professor of Anesthesiology at the University Medical Center Hamburg-Eppendorf, Germany, is a leading authority in haemodynamic monitoring and individualised blood pressure targets. He is an editor of the British Journal of Anaesthesia and is one of the leading clinical researchers in perioperative haemodynamic monitoring and blood pressure management in Europe. Prof. Saugel led the German Society of Anaesthesiology and Intensive Care Medicine’s 2024 guidelines on intraoperative haemodynamic monitoring and was co-first author on the 2025 ESAIC consensus statement on the same topic. He will present “Individualised perioperative blood pressure management in patients undergoing major abdominal surgery: The IMPROVE-multi randomised trial”. This trial explored “if the relationship between intraoperative hypotension and organ injury is causal and if targeted blood pressure management can improve outcomes in surgical patients”. (7) It enrolled adults scheduled for elective major abdominal surgery under general anaesthesia who had at least one additional high-risk criterion. He will explore whether, among high-risk patients undergoing major abdominal surgery, individualized perioperative blood pressure management decreases the incidence of postsurgical complications compared with routine blood pressure management.  

Dr. Denise Veelo, a full professor of Anesthesiology at the Amsterdam University Medical Center, The Netherlands, specialises in perioperative haemodynamics. She will present “Proactive vs reactive treatment of hypotension during surgery: The PRETREAT randomised trial”, which was published in JAMA last year. She will explore outcomes from this trial that showed that standard reactive management leaves most patients exposed to periods of hypotension and whether a proactive strategy with personalised higher MAP targets ensures better outcomes. The trial enrolled adults scheduled for elective non-cardiac surgery under general or central neuraxial anaesthesia. Prior to surgery, each participant was assessed using a centre-specific preoperative risk score and stratified into risk categories for intraoperative hypotension. In the proactive management group, patients were assigned a risk-stratified mean arterial pressure (MAP) target together with a simplified clinical guideline to guide intraoperative blood pressure management. In contrast, the comparison group received their usual care as routinely practised in the participating hospitals, without additional protocol guidance. Using a short questionnaire (Whodas 2.0), patients were assessed post-surgery over a defined period to check for complications. Researchers updated the guidelines as needed in an “adaptive” approach, making sure the new method worked in real life before the full trial continued. (8)(9) 

Prof. Dr. Wolfgang Buhre holds the chair in Anaesthesiology at the University Medical Centre, Utrecht, The Netherlands, and is Professor of Perioperative Medicine and Anaesthesiology at the University of Utrecht. He is the Past President of the European Society of Anaesthesiology and Intensive Care (ESAIC). With Prof. Saugel, Prof. Buhre co-authored the 2025 ESAIC consensus statement on intraoperative haemodynamic monitoring. Developed by 25 international experts, this statement made recommendations for intraoperative arterial pressure management and MAP, while also recommending identifying the underlying causes of intraoperative hypotension. (10) 

He will round off this session with “Summary and discussion: facts, figures and myths”, and offer his interpretation of these trials. Prof. Buhre will address the myths that have arisen from relying solely on observational data and the limitations born of the composite outcomes from both observational and randomised trials that require further evidence before being resolved.  

The spotlight session “Blood pressure management: myths, studies and science” will take place at the Euroanaesthesia Congress 2026 on Sunday, June 7 at 11:00 – 12:00 CEST in room DELTA A. 

References 

1. Pearse RM, Moreno RP, Bauer P, Pelosi P, Metnitz P, Spies C, et al. European Surgical Outcomes Study (EuSOS) group for the Trials groups of the European Society of Intensive Care Medicine and the European Society of Anaesthesiology. Mortality after surgery in Europe: a 7 day cohort study. Lancet. 2012;380:1059–65. doi: 10.1016/S0140-6736(12)61148-9. https://pmc.ncbi.nlm.nih.gov/articles/PMC3493988/ 

2. Devereaux PJ, Sessler DI. Cardiac complications in patients undergoing major noncardiac surgery. N Engl J Med. 2015;373:2258–69. doi: 10.1056/NEJMra1502824. https://pubmed.ncbi.nlm.nih.gov/26630144/  

3. Walsh M, Devereaux PJ, Garg AX, Kurz A, Turan A, Rodseth RN, Cywinski J, Thabane L, Sessler DI. Relationship between intraoperative mean arterial pressure and clinical outcomes after noncardiac surgery: toward an empirical definition of hypotension. Anesthesiology. 2013 Sep;119(3):507-15. doi: 10.1097/ALN.0b013e3182a10e26. PMID: 23835589. https://journals.lww.com/anesthesiology/fulltext/2017/01000/relationship_between_intraoperative_hypotension,.17.aspx  

4. D’Amico F, Fominskiy EV, Turi S, Pruna A, Fresilli S, Triulzi M, Zangrillo A, Landoni G. Intraoperative hypotension and postoperative outcomes: a meta-analysis of randomised trials. Br J Anaesth. 2023 Nov;131(5):823-831. doi: 10.1016/j.bja.2023.08.026. Epub 2023 Sep 20. PMID: 37739903. https://www.bjanaesthesia.org/article/S0007-0912(23)00479-8/fulltext  

5. Walsh M, Devereaux PJ, Garg AX, Kurz A, Turan A, Rodseth RN, Cywinski J, Thabane L, Sessler DI. Relationship between intraoperative mean arterial pressure and clinical outcomes after noncardiac surgery: toward an empirical definition of hypotension. Anesthesiology. 2013 Sep;119(3):507-15. doi: 10.1097/ALN.0b013e3182a10e26. PMID: 23835589. https://journals.lww.com/anesthesiology/fulltext/2017/01000/relationship_between_intraoperative_hypotension,.17.aspx  

6. Kant M, van Klei WA, Hollmann MW, Veelo DP, Kappen TH; PRETREAT study group. The effect of proactive versus reactive treatment of hypotension on postoperative disability and outcome in surgical patients under anaesthesia (PRETREAT): clinical trial protocol and considerations. BJA Open. 2024;9:100262. Published 2024 Feb 29. doi:10.1016/j.bjao.2024.100262 https://www.bjaopen.org/article/S2772-6096(24)00006-6/fulltext  

7. Saug el B, Meidert AS, Brunkhorst FM, et al. Individualized Perioperative Blood Pressure Management in Patients Undergoing Major Abdominal Surgery: The IMPROVE-multi Randomized Clinical Trial. JAMA. 2025;334(21):1893–1904. doi:10.1001/jama.2025.17235 

8. Kant, M., van Klei, W. A., Hollmann, M. W., Veelo, D. P., Kappen, T. H., de Klerk, E., Vernooij, L., & The PRETREAT study group (2024). The effect of proactive versus reactive treatment of hypotension on postoperative disability and outcome in surgical patients under anaesthesia (PRETREAT): clinical trial protocol and considerations. BJA Open, 9, Article 100262. https://doi.org/10.1016/j.bjao.2024.100262  

9. Kant M, van Klei WA, Hollmann MW, et al. Proactive vs Reactive Treatment of Hypotension During Surgery: The PRETREAT Randomized Clinical Trial. JAMA. 2025;334(21):1905–1914. doi:10.1001/jama.2025.18007 https://jamanetwork.com/journals/jama/fullarticle/2840159 

10. Saugel B, Buhre W, Chew MS, Cholley B, Coburn M, Cohen B, et al. Intra-operative haemodynamic monitoring and management of adults having noncardiac surgery: A statement from the European Society of Anaesthesiology and Intensive Care. Eur J Anaesthesiol. 2025 Jun;42(6):543–556. doi: 10.1097/EJA.0000000000002174. https://pubmed.ncbi.nlm.nih.gov/40308048/