Withholding versus Continuing Angiotensin-converting Enzyme Inhibitors or Angiotensin II Receptor Blockers before Noncardiac Surgery

PeriOperative Quality Initiative (POQI) international consensus statement on perioperative arterial pressure management

Arterial pressure monitoring and management are mainstays of haemodynamic therapy in patients having surgery. This article presents updated consensus statements and recommendations on perioperative arterial pressure management developed during the 11th POQI PeriOperative Quality Initiative (POQI) consensus conference held in London, UK, on June 4-6, 2023, which included a diverse group of international experts. Based on a modified Delphi approach, we recommend keeping intraoperative mean arterial pressure ≥60 mm Hg in at-risk patients. We further recommend increasing mean arterial pressure targets when venous or compartment pressures are elevated and treating hypotension based on presumed underlying causes. When intraoperative hypertension is treated, we recommend doing so carefully to avoid hypotension. Clinicians should consider continuous intraoperative arterial pressure monitoring as it can help reduce the severity and duration of hypotension compared to intermittent arterial pressure monitoring. Postoperative hypotension is often unrecognised and might be more important than intraoperative hypotension because it is often prolonged and untreated. Future research should focus on identifying patient-specific and organ-specific hypotension harm thresholds and optimal treatment strategies for intraoperative hypotension including choice of vasopressors. Research is also needed to guide monitoring and management strategies for recognising, preventing, and treating postoperative hypotension.

Postoperative Hypotension After Cardiac Surgery Is Associated With Acute Kidney Injury

OBJECTIVES

To describe the incidence of postoperative hypotension in patients undergoing cardiac surgery during the first 12 hours in the intensive care unit (ICU) and any relationship between hypotension and the development of acute kidney injury (AKI).

DESIGN

This was a retrospective, observational cohort study.

SETTING

The study took place in a single-center tertiary teaching hospital in London, UK.

PARTICIPANTS

Adult patients (n = 100) who underwent elective cardiac surgery requiring intraoperative cardiopulmonary bypass between May and November 2021 were enrolled.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A hypotensive event was defined as mean arterial pressure <65 mmHg lasting at least 1 minute. Invasive blood pressure data was analyzed for the first 12 hours after surgery, and any association between postoperative hypotension and AKI was assessed. A total of 91% of patients experienced hypotension in the first 12 hours postprocedure. On average, patients experienced 9 hypotensive events, with events lasting an average of 5 minutes. A total of 16 patients (16%) developed at least stage 1 AKI. The average duration of hypotension was significantly higher in the AKI group (4.6 min [IQR 3.3, 8.0] v 8.1 min [IQR 5.2, 14.2], p = 0.029). Those suffering AKI had longer ICU and hospital stays.

CONCLUSIONS

This study demonstrated that hypotension in the first 12 hours following cardiac surgery is common and prolonged hypotensive events are associated with developing AKI. This emphasizes the importance of treating hypotension aggressively and highlights a target for further research and intervention.

Impaired angiotensin II signaling in septic shock

Recent years have seen a resurgence of interest for the renin-angiotensin-aldosterone system in critically ill patients. Emerging data suggest that this vital homeostatic system, which plays a crucial role in maintaining systemic and renal hemodynamics during stressful conditions, is altered in septic shock, ultimately leading to impaired angiotensin II-angiotensin II type 1 receptor signaling. Indeed, available evidence from both experimental models and human studies indicates that alterations in the renin-angiotensin-aldosterone system during septic shock can occur at three distinct levels: 1. Impaired generation of angiotensin II, possibly attributable to defects in angiotensin-converting enzyme activity; 2. Enhanced degradation of angiotensin II by peptidases; and/or 3. Unavailability of angiotensin II type 1 receptor due to internalization or reduced synthesis. These alterations can occur either independently or in combination, ultimately leading to an uncoupling between the renin-angiotensin-aldosterone system input and downstream angiotensin II type 1 receptor signaling. It remains unclear whether exogenous angiotensin II infusion can adequately address all these mechanisms, and additional interventions may be required. These observations open a new avenue of research and offer the potential for novel therapeutic strategies to improve patient prognosis. In the near future, a deeper understanding of renin-angiotensin-aldosterone system alterations in septic shock should help to decipher patients' phenotypes and to implement targeted interventions.

Effect of continuing angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers on the day of surgery on myocardial injury after non-cardiac surgery: A retrospective cohort study

STUDY OBJECTIVE

To evaluate the effect of continuing of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) prescriptions 24 h before surgery on postoperative myocardial injury and blood pressure in patients undergoing non-cardiac surgery.

DESIGN

A single-center, retrospective study.

SETTING

Operating room and perioperative care area.

PATIENTS

42,432 patients who had been taking chronic ACEI/ARB underwent non-cardiac surgery from January 2012 to June 2022.

INTERVENTIONS

Patients who discontinued ACEI/ARB 24 h before surgery (withheld group, n=31,055) and those who continued ACEI/ARB 24 h before surgery (continued group, n=11,377).

MEASUREMENTS

Primary outcome was myocardial injury after non-cardiac surgery (MINS) within 7 days postoperatively. MINS was defined as an elevated postoperative cardiac troponin measurement above the 99th percentile of the upper reference limit with a rise/fall pattern. Perioperative blood pressure and clinical outcomes were secondary outcomes.

MAIN RESULTS

Among 42,432 patients, MINS occurred in 2848 patients (6.7%) and was the all-cause of death within 30 days in 122 patients (0.3%). Incidence of MINS was significantly higher in the continued group than the withheld group (847/11,377 [7.4%] vs. 2001/31,055 [6.4%]; OR [95% CI] 1.17 [1.07-1.27]; P<0.001). After 1:1 propensity score matching, 11,373 patients were included in each group. There was still a significant difference for the occurrence of MINS between two groups in matched cohort (7.4% vs. 6.6%, OR [95% CI] 1.14 [1.03-1.26]; P=0.015). Time-average weight of mean arterial pressure <65 mmHg during surgery was significantly higher in the continued group (mean 0.11 vs. 0.09 [95% CI of mean difference] [0.01-0.03]; P<0.001). However, there was no significant difference in other clinical outcomes and mortality.

CONCLUSIONS

Withholding ACEI/ARB before surgery was associated with a reduced risk of intraoperative hypotension and postoperative myocardial injury, but it did not affect overall clinical outcomes in patients undergoing non-cardiac surgery.

One size does not fit all: Perioperative management of patients with heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is recognized as an important risk factor for perioperative complications. However, anesthesia management of HFpEF patients remains a considerable challenge without clear guidance. HFpEF is heterogeneous in its pathophysiological processes, diverse clinical presentations, adverse remodeling of cardiovascular and other organs, and clinical outcomes. It is difficult to manage the disease with one fixed approach because of this. This review phenotypes HFpEF patients by combining their clinical features and anesthesia care issues. Five phenotypes of HFpEF patients are identified: A, O, P, C, and Y. The clinical features, anesthesia implications, and anesthesia management for each phenotype are highlighted and discussed. Such an approach to HFpEF patients in the operating room could deliver safe, high-quality perioperative care.

Hemodynamic effects of withholding vs. continuing angiotensin II receptor blockers on the day of prone positioning spinal surgery in elderly patients

Introduction

The hemodynamic effects of withholding vs. continuing angiotensin II receptor blockers (ARBs) before surgery in elderly patients undergoing spinal surgery in a prone position during anesthesia induction to skin incision are still unknown.

Methods

In this prospective study, 80 patients undergoing spinal surgery in a prone position with general anesthesia, aged 60-79 years, American Society of Anesthesiologists (ASA) II or III, were enrolled. Patients who had ARBs only in their preoperative medication list were randomly divided into two groups at a 1:1 ratio: In Group A, ARBs were continued on the morning of surgery, while in Group B, they were withhold. Norepinephrine was infused to maintain the blood pressure at the baseline level of ±20% during anesthesia induction in all patients. The primary outcome was the consumption of norepinephrine in each group from anesthesia induction to skin incision. The secondary outcomes include changes in invasive arterial blood pressure and heart rate, the fluid infusion volumes, the amounts of anesthetic drugs, and the total time from induction to skin incision.

Results

There were no significant differences in the demographics, the fluid infusion volumes, the amounts of anesthetic drugs, the total time from induction to skin incision, and hemodynamics at different time points (p > 0.05), while significant differences were found in norepinephrine consumption between the two groups (p < 0.001). Compared with Group B, the consumption of norepinephrine increased significantly in Group A (93.3 ± 29.8 vs. 124.1 ± 38.7 μg, p = 0.000). In addition, the same trend was illustrated in the pumping rate of norepinephrine between Group B (0.04 ± 0.01 μg·kg-1·min-1) and Group A (0.06 ± 0.02 μg·kg-1·min-1) (p = 0.004).

Conclusion

Our study conducted in elderly patients with hypotension undergoing prone spinal surgery demonstrated a greater pumping rate of norepinephrine during anesthesia induction in patients with ARBs continuing before surgery than those withholding, indicating that it was more difficult to maintain hemodynamic stability.Clinical Trial Registration: https://www.chictr.org.cn/showproj.html?proj=141081, ChiCTR2100053583.

[Preoperative evaluation of adult patients before elective, non-cardiothoracic surgery : A joint recommendation of the German Society for Anesthesiology and Intensive Care Medicine, the German Society for Surgery and the German Society for Internal Medicine]

The 70 recommendations summarize the current status of preoperative risk evaluation of adult patients prior to elective non-cardiothoracic surgery. Based on the joint publications of the German scientific societies for anesthesiology and intensive care medicine (DGAI), surgery (DGCH), and internal medicine (DGIM), which were first published in 2010 and updated in 2017, as well as the European guideline on preoperative cardiac risk evaluation published in 2022, a comprehensive re-evaluation of the recommendation takes place, taking into account new findings, the current literature, and current guidelines of international professional societies. The revised multidisciplinary recommendation is intended to facilitate a structured and common approach to the preoperative evaluation of patients. The aim is to ensure individualized preparation for the patient prior to surgery and thus to increase patient safety. Taking into account intervention- and patient-specific factors, which are indispensable in the preoperative risk evaluation, the perioperative risk for the patient should be minimized and safety increased. The recommendations for action are summarized under "General Principles (A)," "Advanced Diagnostics (B)," and the "Preoperative Management of Continuous Medication (C)." For the first time, a rating of the individual measures with regard to their clinical relevance has been given in the present recommendation. A joint and transparent agreement is intended to ensure a high level of patient orientation while avoiding unnecessary preliminary examinations, to shorten preoperative examination procedures, and ultimately to save costs. The joint recommendation of DGAI, DGCH and DGIM reflects the current state of knowledge as well as the opinion of experts. The recommendation does not replace the individualized decision between patient and physician about the best preoperative strategy and treatment.

Should renin-angiotensin system inhibitors be held prior to major surgery?

Many patients undergoing surgical procedures have a history of hypertension, diabetes mellitus, heart failure, or a combination. Often, these conditions involve the chronic use of a renin-angiotensin system inhibitor, including angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). Observational studies have suggested that continuing ACEIs/ARBs before major noncardiac surgery can increase the risk of intraoperative hypotension, which might drive postoperative complications such as acute kidney injury, myocardial injury, or stroke. Strong recommendations on how to manage ACEIs/ARBs before surgery are, however, lacking owing to insufficient evidence, mostly limited to data from observational studies. Recently, the SPACE trial investigated the impact of preoperative management of ACEIs/ARBs on postoperative myocardial injury. Myocardial injury occurred in 48.3% patients randomised to discontinue and 41.3% patients randomised to continue ACEI/ARB (odds ratio for continuing: 0.77, 95% confidence interval 0.45-1.31). Patients randomised to the 'Stop' group experienced more postoperative hypertension. In a post hoc analysis, patients randomised to the 'Continue' group with low preoperative NT-proBNP concentrations (<100 pg ml-1) experienced less myocardial injury after surgery than the 'Stop' group, whereas no significant difference was observed in patients with elevated preoperative NT-proBNP concentrations. The SPACE trial provides important and new reassuring data on the safety of continuing ACEIs/ARBs before major surgery, challenging previous beliefs.

Pre-operative maintenance of angiotensin-converting enzyme inhibitors is not associated with acute kidney injury in cardiac surgery patients with cardio-pulmonary bypass: a propensity-matched multicentric analysis

Objective: We investigated the effects of the maintenance of angiotensin-converting enzyme inhibitors (ACE inhibitors) the day of the surgery on the incidence of postoperative acute kidney injury (AKI) and cardiac events in patients undergoing cardiac surgery. Methods: We performed a multicentric observational study with propensity matching on 1,072 patients treated with ACE inhibitors. We collected their baseline demographic data, comorbidities, and operative and postoperative outcomes. AKI was defined by KDIGO (Kidney Disease: Improving Global Outcome). Results: Maintenance of an ACE inhibitor was not associated with an increased risk of AKI (OR: 1.215 (CI95%:0.657-2.24), p = 0.843, 71 patients (25.1%) vs. 68 patients (24%)). Multivariate logistic regression and sensitive analysis did not demonstrate any association between ACE inhibitor maintenance and AKI, following cardiac surgery (OR: 1.03 (CI95%:0.81-1.3)). No statistically significant difference occurs in terms of incidence of cardiogenic shock (OR: 1.315 (CI95%:0.620-2.786)), stroke (OR: 3.313 (CI95%:0.356-27.523)), vasoplegia (OR: 0.741 (CI95%:0.419-1.319)), postoperative atrial fibrillation (OR: 1.710 (CI95%:0.936-3.122)), or mortality (OR: 2.989 (CI95%:0.343-26.034)). ICU and hospital length of stays did not differ (3 [2; 5] vs. 3 [2; 5] days, p = 0.963 and 9.5 [8; 12] vs. 10 [8; 14] days, p = 0.638). Conclusion: Our study revealed that maintenance of ACE inhibitors on the day of the surgery was not associated with increased postoperative AKI. ACE inhibitor maintenance was also not associated with an increased rate of postoperative major cardiovascular events (arterial hypotension, cardiogenic shock, vasopressors use, stroke and death).

Discontinuation vs. continuation of renin-angiotensin system inhibition before non-cardiac surgery: the SPACE trial

BACKGROUND AND AIMS

Haemodynamic instability is associated with peri-operative myocardial injury, particularly in patients receiving renin-angiotensin system (RAS) inhibitors (angiotensin-converting-enzyme inhibitors/angiotensin II receptor blockers). Whether stopping RAS inhibitors to minimise hypotension, or continuing RAS inhibitors to avoid hypertension, reduces peri-operative myocardial injury remains unclear.

METHODS

From 31 July 2017 to 1 October 2021, patients aged ≥60 years undergoing elective non-cardiac surgery were randomly assigned to either discontinue or continue RAS inhibitors prescribed for existing medical conditions in six UK centres. Renin-angiotensin system inhibitors were withheld for different durations (2-3 days) before surgery, according to their pharmacokinetic profile. The primary outcome, masked to investigators, clinicians, and patients, was myocardial injury [plasma high-sensitivity troponin-T (hs-TnT) ≥ 15 ng/L within 48 h after surgery, or ≥5 ng/L increase when pre-operative hs-TnT ≥15 ng/L]. Pre-specified adverse haemodynamic events occurring within 48 h of surgery included acute hypertension (>180 mmHg) and hypotension requiring vasoactive therapy.

RESULTS

Two hundred and sixty-two participants were randomized to continue (n = 132) or stop (n = 130) RAS inhibitors. Myocardial injury occurred in 58 (48.3%) patients randomized to discontinue, compared with 50 (41.3%) patients who continued, RAS inhibitors [odds ratio (for continuing): 0.77; 95% confidence interval (CI) 0.45-1.31]. Hypertensive adverse events were more frequent when RAS inhibitors were stopped [16 (12.4%)], compared with 7 (5.3%) who continued RAS inhibitors [odds ratio (for continuing): 0.4; 95% CI 0.16-1.00]. Hypotension rates were similar when RAS inhibitors were stopped [12 (9.3%)] or continued [11 (8.4%)].

CONCLUSIONS

Discontinuing RAS inhibitors before non-cardiac surgery did not reduce myocardial injury, and could increase the risk of clinically significant acute hypertension. These findings require confirmation in future studies.

Preoperative Renin-Angiotensin System Antagonists Intake and Blood Pressure Responses During Ambulatory Surgical Procedures: A Prospective Cohort Study

BACKGROUND

There is limited evidence to inform the association between the intake of angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin II receptor blockers (ARBs) and intraoperative blood pressure (BP) changes in an ambulatory surgery population.

METHODS

Adult patients who underwent ambulatory surgery and were discharged on the same day or within 24 hours of their procedure were enrolled in this prospective cohort study. The primary outcome of the study was early intraoperative hypotension (first 15 minutes of induction). Secondary outcomes included any hypotension, BP variability, and recovery. Hypotension was defined as a decrease in systolic BP of >30% from baseline for ≥5 minutes or a mean BP of <55 mm Hg. Four exposure groups were compared (no antihypertensives, ACEI/ARB intake <10 hours before surgery, ACEI/ARB intake ≥10 hours before surgery, and other antihypertensives).

RESULTS

Of the 537 participants, early hypotension was observed in 25% (n = 134), and any hypotension in 41.5% (n = 223). Early hypotension occurred in 30% (29 of 98) and 41% (17 of 41) with the intake of ACEI/ARBs <10 and ≥10 hours before surgery, respectively, compared to 30% (9 of 30) with other antihypertensives and 21% (79 of 368) with no antihypertensives ( P = .02). Those on antihypertensives also experienced any hypotension more frequently than those who were not on antihypertensives ( P < .001). After adjusting for age and baseline BP in a regression analysis, antihypertensive exposure groups were observed to be associated only with any intraoperative hypotension ( P = .012). In the ACEI/ARB subset, there was no evidence of an association between time since the last ACEI/ARB dose, and hypotension or minimum mean or systolic BP. Compared to normal baseline BP, BP ≥ 140/90 mm Hg increased the odds of early and any hypotension (odds ratio [OR], 3.9; 95% confidence interval [CI], 2.1-7.1 and OR, 7.7; 95% CI, 3.7-14.9, respectively; P < .001). Intraoperative variability in systolic and diastolic BP demonstrated significant differences with age, baseline BP, and antihypertensive exposure group ( P < .001).

CONCLUSIONS

Early and any hypotension occurred more frequently in those on antihypertensives than those not on antihypertensives. Unadjusted associations between antihypertensive exposure and intraoperative hypotension were largely explained by baseline hypertension rather than the timing of ACEI/ARBs or type of antihypertensive exposure. Patients with hypertension and on treatment experience more intraoperative BP variability and should be monitored appropriately.

Perioperative Management of Novel Pharmacotherapies for Heart Failure and Pulmonary Hypertension

Heart failure (HF) and pulmonary hypertension (PH) are increasingly prevalent comorbidities in patients presenting for noncardiac surgery. The unique pathophysiology and pharmacotherapies associated with these syndromes have important perioperative implications. As new medications for HF and PH emerge, it is imperative that anesthesiologists and other perioperative providers understand their mechanisms of action, pharmacokinetics, and potential adverse effects. We present an overview of the novel HF and PH pharmacotherapies and strategies for their perioperative management.

Perioperative Optimization and Management of the Oral and Maxillofacial Surgical Patient: A Narrative Review on Updates in Anticoagulation, Hypertension and Diabetes Medications

PURPOSE

The preoperative management guidelines of surgical patients are constantly evolving as newer evidence-based research is published. Oral and maxillofacial surgeons need to be current with the increasingly more complex new drug therapies and updated national association(s) guidelines. This narrative review provides a synopsis with important reference tables for updated preoperative optimization guidelines for anticoagulation, antiplatelet therapy, antihypertensive management, and glycemic control in the preoperative period for the oral and maxillofacial surgery patient. It also includes the most current anesthesia guidelines on glucagon-like peptide receptor agonists.

METHODS

The search strategy utilized pubmed.gov to identify the most recent national society guidelines and review articles pertinent to perioperative anticoagulation, antiplatelet therapy, antihypertensive management, and glycemic control.

RESULTS

The search identified 75 articles from the American College of Surgeons, American Heart Association, American Society of Anesthesiologists, American College of Cardiologists, in addition to recent reviews discussing the standard of care for optimization of patients in the perioperative period.

CONCLUSION

Medical optimization prior to surgery is important for safe and efficient surgical practice and has been shown to improve overall mortality. This narrative review provides a summary of the current data with recommendations focusing on four key points.

Performance of a Machine Learning Algorithm to Predict Hypotension in Spontaneously Breathing Non-Ventilated Post-Anesthesia and ICU Patients

Background: Hypotension is common in the post-anesthesia care unit (PACU) and intensive care unit (ICU), and is associated with adverse patient outcomes. The Hypotension Prediction Index (HPI) algorithm has been shown to accurately predict hypotension in mechanically ventilated patients in the OR and ICU and to reduce intraoperative hypotension (IOH). Since positive pressure ventilation significantly affects patient hemodynamics, we performed this validation study to examine the performance of the HPI algorithm in a non-ventilated PACU and ICU population. Materials & Methods: The performance of the HPI algorithm was assessed using prospectively collected blood pressure (BP) and HPI data from a PACU and a mixed ICU population. Recordings with sufficient time (≥3 h) spent without mechanical ventilation were selected using data from the electronic medical record. All HPI values were evaluated for sensitivity, specificity, predictive value, and time-to-event, and a receiver operating characteristic (ROC) curve was constructed. Results: BP and HPI data from 282 patients were eligible for analysis, of which 242 (86%) were ICU patients. The mean age (standard deviation) was 63 (13.5) years, and 186 (66%) of the patients were male. Overall, the HPI predicted hypotension accurately, with an area under the ROC curve of 0.94. The most used HPI threshold cutoff in research and clinical use, 85, showed a sensitivity of 1.00, specificity of 0.79, median time-to-event of 160 s [60-380], PPV of 0.85, and NPV of 1.00. Conclusion: The absence of positive pressure ventilation and the influence thereof on patient hemodynamics does not negatively affect the performance of the HPI algorithm in predicting hypotension in the PACU and ICU. Future research should evaluate the feasibility and influence on hypotension and outcomes following HPI implementation in non-ventilated patients at risk of hypotension.

The State of Use and Utility of Negative Controls in Pharmacoepidemiologic Studies

Uses of real-world data in drug safety and effectiveness studies are often challenged by various sources of bias. We undertook a systematic search of the published literature through September 2020 to evaluate the state of use and utility of negative controls to address bias in pharmacoepidemiologic studies. Two reviewers independently evaluated study eligibility and abstracted data. Our search identified 184 eligible studies for inclusion. Cohort studies (115, 63%) and administrative data (114, 62%) were, respectively, the most common study design and data type used. Most studies used negative control outcomes (91, 50%), and for most studies the target source of bias was unmeasured confounding (93, 51%). We identified 4 utility domains of negative controls: 1) bias detection (149, 81%), 2) bias correction (16, 9%), 3) P-value calibration (8, 4%), and 4) performance assessment of different methods used in drug safety studies (31, 17%). The most popular methodologies used were the 95% confidence interval and P-value calibration. In addition, we identified 2 reference sets with structured steps to check the causality assumption of the negative control. While negative controls are powerful tools in bias detection, we found many studies lacked checking the underlying assumptions. This article is part of a Special Collection on Pharmacoepidemiology.

Desmopressin to reduce periprocedural bleeding and transfusion: a systematic review and meta-analysis

We systematically reviewed the literature to investigate the effects of peri-procedural desmopressin in patients without known inherited bleeding disorders undergoing surgery or other invasive procedures. We included 63 randomized trials (4163 participants) published up to February 1, 2023. Seven trials were published after a 2017 Cochrane systematic review on this topic. There were 38 trials in cardiac surgery, 22 in noncardiac surgery, and 3 in non-surgical procedures. Meta-analyses demonstrated that desmopressin likely does not reduce the risk of receiving a red blood cell transfusion (25 trials, risk ratio [RR] 0.95, 95% confidence interval [CI] 0.86 to 1.05) and may not reduce the risk of reoperation due to bleeding (22 trials, RR 0.75, 95% CI 0.47 to 1.19) when compared to placebo or usual care. However, we demonstrated significant reductions in number of units of red blood cells transfused (25 trials, mean difference -0.55 units, 95% CI - 0.94 to - 0.15), total volume of blood loss (33 trials, standardized mean difference - 0.40 standard deviations; 95% CI - 0.56 to - 0.23), and the risk of bleeding events (2 trials, RR 0.45, 95% CI 0.24 to 0.84). The certainty of evidence of these findings was generally low. Desmopressin increased the risk of clinically significant hypotension that required intervention (19 trials, RR 2.15, 95% CI 1.36 to 3.41). Limited evidence suggests that tranexamic acid is more effective than desmopressin in reducing transfusion risk (3 trials, RR 2.38 favoring tranexamic acid, 95% CI 1.06 to 5.39) and total volume of blood loss (3 trials, mean difference 391.7 mL favoring tranexamic acid, 95% CI - 93.3 to 876.7 mL). No trials directly informed the safety and hemostatic efficacy of desmopressin in advanced kidney disease. In conclusion, desmopressin likely reduces periprocedural blood loss and the number of units of blood transfused in small trials with methodologic limitations. However, the risk of hypotension needs to be mitigated. Large trials should evaluate desmopressin alongside tranexamic acid and enroll patients with advanced kidney disease.

Perioperative cardiac risk reduction in non cardiac surgery

For patients undergoing nonemergent noncardiac surgery, care must be taken to identify patients at increased risk of major adverse cardiovascular events, as these remain a significant source of perioperative morbidity and mortality. Identification of at-risk patients requires careful attention to risk factors including assessment of functional status, medical comorbidities, and a medication assessment. After identification, to minimize perioperative cardiac risk, care should be taken through a combination of appropriate medication management, close monitoring for cardiovascular ischemic events, and optimization of pre-existing medical conditions. There are multiple society guidelines that aim to mitigate risk of cardiovascular morbidity and mortality in patients undergoing nonemergent noncardiac surgery. However, the rapid evolution of medical literature often creates gaps between the existing evidence and best practice recommendations. In this review, we aim to reconcile the recommendations made in the guidelines from the major cardiovascular and anesthesiology societies from the USA, Canada, and Europe, and to provide updated recommendations based on new evidence.

Prediction of worsening postoperative renal function in older candidates to elective cardiac surgery: Choosing the best eGFR formula may not be enough

BACKGROUND

Though renal impairment is highly prevalent in older patients and influence post-operative outcomes in cardiac surgery; its prognostic relevance is debated and not fully assessed by surgical risk scores.

OBJECTIVE

We investigated the predictive role of estimated glomerular filtration rate formulas for in-hospital worsening renal function (WRF) after cardiac surgery.

METHODS

We prospectively enrolled in single-center cohort study, patients aged ≥ 75 years candidate to elective cardiac surgery. Four creatinine-based equations were used to calculate estimated glomerular filtration rate (eGFR) formulas: Cockroft-Gault, Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology, and Berlin Initiative Study 1 formulas. Each patient underwent geriatric and clinical evaluation before surgery with calculation of the Society of Thoracic Surgeons scores. In-hospital WRF was defined as a composite of an increase in SCr ≥0.5 mg/dl or the occurrence of grade III KDIGO acute kidney injury. The association between each eGFR equation, alone and in models including clinical variables, and WRF was analyzed using logistic regressions and ROC analysis.

RESULTS

WRF occurred in 69 patients (19.8%), and the predictors of WRF were previous acute myocardial infarction, hypertension, 4-mt gait speed performance, and preoperative eGFR, irrespective of the equation used. With all equations, inclusion of these additional variables in the logistic regression models improved the prediction of WRF (AUCs 0.798-0.810).

CONCLUSIONS

An accurate assessment of renal function and of physical performance should be incorporated into cardiac surgery risk scores to improve prediction of in-hospital WRF and, hence, risk stratification in older adults undergoing elective cardiac surgery.

Prevention of perioperative stroke in patients undergoing non-cardiac surgery

About 300 million adults undergo non-cardiac surgery annually. Although, in this setting, the incidence of perioperative stroke is low, the absolute number of patients experiencing a stroke is substantial. Furthermore, most patients with this complication will die or end up with severe disability. Covert brain infarctions are more frequent than overt strokes and are associated with postoperative delirium, cognitive decline, and cerebrovascular events at 1 year after surgery. Evidence shows that traditional stroke risk factors including older age, hypertension, and atrial fibrillation are also associated with perioperative stroke; previous stroke is the strongest risk factor for perioperative stroke. Increasing evidence also suggests the pathogenic role of perioperative events, such as hypotension, new atrial fibrillation, paradoxical embolism, and bleeding. Clinicians involved in perioperative care should be aware of this evidence on prevention strategies to improve patient outcomes after non-cardiac surgery.

Future Directions in Optimizing Anesthesia to Reduce Perioperative Acute Kidney Injury

BACKGROUND

Perioperative acute kidney injury (AKI) is common in surgical patients and is associated with high morbidity and mortality. There are currently few options for AKI prevention and treatment. Due to its complex pathophysiology, there is no efficient medication therapy to stop the onset of the injury or repair the damage already done. Certain anesthetics, however, have been demonstrated to affect the risk of perioperative AKI in some studies. The impact of anesthetics on renal function is particularly important as it is closely related to the prognosis of patients. Some anesthetics can induce anti-inflammatory, anti-necrotic, and anti-apoptotic effects. Propofol, sevoflurane, and dexmedetomidine are a few examples of anesthetics that have protective association with AKI in the perioperative period.

SUMMARY

In this study, we reviewed the clinical characteristics, risk factors, and pathogenesis of AKI. Subsequently, the protective effects of various anesthetic agents against perioperative AKI and the latest research are introduced.

KEY MESSAGE

This work demonstrates that a thorough understanding of the reciprocal effects of anesthetic drugs and AKI is crucial for safe perioperative care and prognosis of patients. However, more complete mechanisms and pathophysiological processes still need to be further studied.

Medical Management of Cardiovascular Disease

We offer an overview of lipid lowering, antiplatelet, antihypertensive, and glucose-lowering therapies for vascular surgeons and their respective medical teams. Further reviews should offer additional guidance on smoking cessation, exercise therapy, and nutritional optimization.

Cardiovascular risk management in the peri-operative setting

Peri-operative cardiovascular events occur in up to 3% of patients undergoing non-cardiac surgery. Accurate cardiovascular risk assessment is important in the peri-operative setting, as it allows informed and shared decisions regarding the appropriateness of proceeding with surgery, guides surgical and anaesthetic approaches, and may influence the use of preventive medications and post-operative cardiac monitoring. Quantitative risk assessment may also inform a reconsideration of choosing a more limited lower risk type of surgery, or conservative management. Pre-operative cardiovascular risk assessment starts with clinical assessment and should include an estimate of functional capacity. Specialised cardiac investigations are rarely indicated specifically to assess pre-operative cardiovascular risk. The decision regarding cardiac investigations is influenced by the nature, extent and urgency of surgery. The strategy of performing pre-operative revascularisation to improve post-operative outcomes is not evidence-based and recent international guidelines recommend against this.

Hypotension-Avoidance Versus Hypertension-Avoidance Strategies in Noncardiac Surgery : An International Randomized Controlled Trial

BACKGROUND

Among patients having noncardiac surgery, perioperative hemodynamic abnormalities are associated with vascular complications. Uncertainty remains about what intraoperative blood pressure to target and how to manage long-term antihypertensive medications perioperatively.

OBJECTIVE

To compare the effects of a hypotension-avoidance and a hypertension-avoidance strategy on major vascular complications after noncardiac surgery.

DESIGN

Partial factorial randomized trial of 2 perioperative blood pressure management strategies (reported here) and tranexamic acid versus placebo. (ClinicalTrials.gov: NCT03505723).

SETTING

110 hospitals in 22 countries.

PATIENTS

7490 patients having noncardiac surgery who were at risk for vascular complications and were receiving 1 or more long-term antihypertensive medications.

INTERVENTION

In the hypotension-avoidance strategy group, the intraoperative mean arterial pressure target was 80 mm Hg or greater; before and for 2 days after surgery, renin-angiotensin-aldosterone system inhibitors were withheld and the other long-term antihypertensive medications were administered only for systolic blood pressures 130 mm Hg or greater, following an algorithm. In the hypertension-avoidance strategy group, the intraoperative mean arterial pressure target was 60 mm Hg or greater; all antihypertensive medications were continued before and after surgery.

MEASUREMENTS

The primary outcome was a composite of vascular death and nonfatal myocardial injury after noncardiac surgery, stroke, and cardiac arrest at 30 days. Outcome adjudicators were masked to treatment assignment.

RESULTS

The primary outcome occurred in 520 of 3742 patients (13.9%) in the hypotension-avoidance group and in 524 of 3748 patients (14.0%) in the hypertension-avoidance group (hazard ratio, 0.99 [95% CI, 0.88 to 1.12]; P = 0.92). Results were consistent for patients who used 1 or more than 1 antihypertensive medication in the long term.

LIMITATION

Adherence to the assigned strategies was suboptimal; however, results were consistent across different adherence levels.

CONCLUSION

In patients having noncardiac surgery, our hypotension-avoidance and hypertension-avoidance strategies resulted in a similar incidence of major vascular complications.

PRIMARY FUNDING SOURCE

Canadian Institutes of Health Research, National Health and Medical Research Council (Australia), and Research Grant Council of Hong Kong.

Association of intraoperative hypotension and severe postoperative complications during non-cardiac surgery in adult patients: A systematic review and meta-analysis

Background

Intraoperative hypotension (IOH) is a common side effect of non-cardiac surgery that might induce poor postoperative outcomes. The relationship between the IOH and severe postoperative complications is still unclear. Thus, we summarized the existing literature to evaluate whether IOH contributes to developing severe postoperative complications during non-cardiac surgery.

Methods

We conducted a comprehensive search of PubMed, Embase, Cochrane Library, Web of Science, and the CBM from inception to 15 September 2022. The primary outcomes were 30-day mortality, acute kidney injury (AKI), major adverse cardiac events (myocardial injury or myocardial infarction), postoperative cognitive dysfunction (POCD), and postoperative delirium (POD). Secondary outcomes included surgical-site infection (SSI), stroke, and 1-year mortality.

Results

72 studies (3 randomized; 69 non-randomized) were included in this study. Low-quality evidence showed IOH resulted in an increased risk of 30-day mortality (OR, 1.85; 95% CI, 1.30-2.64; P < .001), AKI (OR, 2.69; 95% CI, 2.15-3.37; P < .001), and stroke (OR, 1.33; 95% CI, 1.21-1.46; P < .001) after non-cardiac surgery than non-IOH. Very low-quality evidence showed IOH was associated with a higher risk of myocardial injury (OR, 2.00; 95% CI, 1.17-3.43; P = .01), myocardial infarction (OR, 2.11; 95% CI, 1.41-3.16; P < .001), and POD (OR, 2.27; 95% CI, 1.53-3.38; P < .001). Very low-quality evidence showed IOH have a similar incidence of POCD (OR, 2.82; 95% CI, 0.83-9.50; P = .10) and 1-year-mortality (OR, 1.66; 95% CI, 0.65-4.20; P = .29) compared with non-IOH in non-cardiac surgery.

Conclusion

Our results suggest IOH was associated with an increased risk of severe postoperative complications after non-cardiac surgery than non-IOH. IOH is a potentially avoidable hazard that should be closely monitored during non-cardiac surgery.

Perioperative Renin-Angiotensin System Inhibitors Improve Major Outcomes of Heart Failure Patients Undergoing Cardiac Surgery: A Propensity-Adjusted Cohort Study

OBJECTIVE

The aim of this study was to study the association of perioperative administration of renin angiotensin system inhibitors (RASi) and clinical outcomes of patients with heart failure (HF) undergoing cardiac surgery.

SUMMARY BACKGROUND DATA

It is controversial whether the perioperative RASi should be administered in HF patients undergoing cardiac surgery.

METHODS

A total of 2338 patients with HF and undergoing CABG and/or valve surgeries at multiple hospitals from 2001 to 2015 were identified from STS database. After adjustment using propensity score and instrumental variable, logistic regression was conducted to analyze the influence of preoperative continuation of RASi (PreRASi) on short-term in-hospital outcomes. Independent risk factors of 30-day mortality, major adverse cardiovascular events (MACE), and renal failure were analyzed by use of stepwise logistic regression. The effects of pre- and postoperative use of RASi (PostRASi) on long-term mortality were analyzed using survival analyses. Stepwise Cox regression was conducted to analyze the independent risk factors of 6-year mortality. The relationships of HF status and surgery type with perioperative RASi, as well as PreRASi-PostRASi, were also evaluated by subgroup analyses.

RESULTS

PreRASi was associated with lower incidences of 30-day mortality [ P < 0.0001, odds ratio (OR): 0.556, 95% confidence interval (CI) 0.405-0.763], stroke ( P =0.035, OR: 0.585, 95% CI: 0.355-0.962), renal failure ( P =0.007, OR: 0.663, 95% CI: 0.493-0.894). Both PreRASi ( P =0.0137) and PostRASi ( P =0.007) reduced 6-year mortality compared with the No-RASi groups.

CONCLUSIONS

Pre- and postoperative use of RASi was associated with better outcomes for the patients who have HF and undergo CABG and/or valve surgeries. Preoperative continuation and postoperative restoration are warranted in these patients.

Depth of anaesthesia and mortality after cardiac or noncardiac surgery: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Recent randomised controlled trials have failed to show a benefit in mortality by using processed electroencephalography (pEEG) to guide lighter anaesthesia. We performed a meta-analysis of mortality data from randomised trials of pEEG monitoring to assess the evidence of any protective effect of pEEG-guided light anaesthesia compared with deep anaesthesia in adults aged ≥18 yr.

METHODS

Our study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. In February 2022, we searched three databases (Cochrane CENTRAL, OVID Medline, EMBASE) for RCTs of pEEG monitoring that provided mortality data at 30 days, 90 days, and/or 1 yr or longer.

RESULTS

We included 16 articles from 12 RCTs with 48 827 total participants. We observed no statistically significant mortality reduction with light anaesthesia compared with deep anaesthesia in patients aged ≥18 yr when all studies were pooled (odds ratio [OR]=0.99; 95% confidence interval (CI), 0.92-1.08). This result did not change significantly when analysing mortality at 30 days, 90 days, 1 yr or longer. We observed no mortality benefit for pEEG monitoring compared with usual care (OR=1.02; 95% CI, 0.89-1.18), targeting higher pEEG index values compared with lower values (OR=0.89; 95% CI, 0.60-1.32), or low pEEG index value alerts compared with no alerts (OR=1.02; 95% CI, 0.41-2.52).

CONCLUSIONS

pEEG-guided lighter anaesthesia does not appear to reduce the risk of postoperative mortality. The absence of a plausible rationale for why deeper anaesthesia should increase mortality has hampered appropriate design of definitive clinical trials.

CLINICAL TRIAL REGISTRATION

CRD42022285195 (PROSPERO).

Updates in the Management of Perioperative Vasoplegic Syndrome

Vasoplegic syndrome occurs relatively frequently in cardiac surgery, liver transplant, major noncardiac surgery, in post-return of spontaneous circulation situations, and in pateints with sepsis. It is paramount for the anesthesiologist to understand both the pathophysiology of vasoplegia and the different treatment strategies available for rescuing a patient from life-threatening hypotension.

Association of intraoperative dexmedetomidine use with postoperative hypotension in unilateral hip and knee arthroplasties: a historical cohort study

PURPOSE

Dexmedetomidine is frequently used as a sedative agent for orthopedic surgery patients undergoing total hip or knee arthroplasty. Although the benefits of dexmedetomidine are well described in the literature, there is also potential for harm, especially regarding the hemodynamic effects of dexmedetomidine in the postoperative setting.

METHODS

This historical cohort study included all primary unilateral total hip or knee arthroplasties conducted from April 2017 to February 2020 in a single, university-affiliated, tertiary care centre (Jewish General Hospital, Montreal, QC, Canada). We used multivariable logistic regression to analyze the predictors for postoperative hypotension, defined as a systolic blood pressure < 90 mm Hg or any systolic blood pressure while on a vasopressor infusion in the postanesthesia care unit. Models were validated using calibration and discrimination with bootstrapping technique.

RESULTS

One thousand five hundred and eighty-eight patients were included in this study. Postoperative hypotension occurred in 413 (26%) patients. Statistically significant predictors for postoperative hypotension included female sex (adjusted odds ratio [aOR], 3.24; 95% confidence interval [CI], 2.29 to 4.58), a history of transient ischemic attack or cerebrovascular accident (aOR, 1.97; 95% CI, 1.04 to 3.72), and intraoperative dexmedetomidine use (aOR, 2.61; 95% CI, 1.99 to 3.42). Moreover, the risk of postoperative hypotension was approximately two times higher than baseline, with a total intraoperative dexmedetomidine dose above 50 μg (relative risk, 1.99; 95% CI, 1.63 to 2.44; P < 0.001). A higher preoperative systolic blood pressure (aOR, 0.98; 95% CI, 0.97 to 0.99) was a protective factor for postoperative hypotension.

CONCLUSION

In this historical cohort study, dexmedetomidine was a strong risk factor for postoperative hypotension in total hip or knee arthroplasty patients. Dexmedetomidine, and particularly at high cumulative doses above 50 μg, should be administered judiciously in high-risk surgical patients to minimize the risk of postoperative hypotension.

Predictors of hypotension during anesthesia induction in patients with hypertension on medication: a retrospective observational study

Background

Hypotension during anesthesia induction is a common event, and occurs more frequently in patients with hypertension than in healthy individuals. Intraoperative hypotension in non-cardiac surgery is reportedly associated with various postoperative complications. However, the predictors of hypotension during anesthesia induction in patients with hypertension have not yet been ascertained. Therefore, we aimed to determine the predictors of hypotension during anesthesia induction in patients with hypertension on medication focusing on the half-life of the medication used.

Methods

In this retrospective observational study, we enrolled patients with hypertension on medication who underwent general anesthesia for oral and maxillofacial surgery between January 1, 2013, and December 31, 2019. Multivariable logistic regression analysis was conducted to test for associations between clinical factors and hypotension during anesthesia induction in patients with hypertension on medication.

Results

A total of 395 patients were included in this study. The risk factors for hypotension during anesthesia induction in patients with hypertension on medication were pre-induction mean arterial blood pressure (adjusted unit odds ratio, 0.96 [95% confidence interval, 0.94 to 0.98]), female sex (adjusted odds ratio [aOR], 1.63 [1.03 to 2.57]), regular use of angiotensin receptor blockers (ARBs)/angiotensin-converting enzyme inhibitors (ACE-Is) with a long half-life (vs. no regular use of ARBs/ACE-Is aOR, 4.02 [1.77 to 9.12]; vs. regular use of ARBs/ACE-Is with a short-to-middle half-life aOR, 3.17 [1.46 to 6.85]), and regular use of beta blockers (aOR, 2.45 [1.19 to 5.04]). Regular use of calcium channel blockers (aOR, 0.44 [0.25 to 0.77]) was a suppressive factor for hypotension during anesthesia induction in patients with hypertension.

Conclusions

In patients with hypertension on medication, regular use of ARBs/ACE-Is with a long half-life, regular use of beta blockers, low pre-induction mean arterial blood pressure, and female sex were risk factors for hypotension during anesthesia induction. Notably, regular use of ARBs/ACE-Is with a long half-life was a high-risk factor for hypotension during anesthesia induction in patients with hypertension on medication even after a 24-h preoperative withdrawal period.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01899-9.

Maximum inferior vena cava diameter predicts post-induction hypotension in hypertensive patients undergoing non-cardiac surgery under general anesthesia: A prospective cohort study

Background

Inferior vena cava (IVC) ultrasonography is a reliable variable that predicts post-induction hypotension (PIH) in patients undergoing surgery under general anesthesia. However, in patients with hypertension, the predictive performance of ultrasound IVC measurements needs further exploration.

Methods

This is a prospective cohort study. Adult patients with existing hypertension scheduled to undergo non-cardiac surgery under general anesthesia were eligible. An abdominal ultrasound examination was conducted immediately prior to anesthesia induction (0.03 mg kg^–1 midazolam, 0.3 mg kg^–1 etomidate, 0.4 μg kg^–1 sufentanil, and 0.6 mg kg^–1 rocuronium). IVC collapsibility index (IVC-CI) was calculated as (dIVC_max–dIVC_min)/dIVC_max, where dIVC_max and dIVC_min represent the maximum and minimum IVC diameters at the end of expiration and inspiration, respectively. PIH was defined as a reduction of mean arterial pressure (MAP) by >30% of the baseline or to <60 mmHg within 10 min after endotracheal intubation. The diagnostic performance of IVC-CI, dIVC_max, and dIVC_min in predicting PIH was also examined in a group of normotensive patients receiving non-cardiac surgery under the same anesthesia protocol.

Results

A total of 51 hypertensive patients (61 ± 13 years of age, 31 women) and 52 normotensive patients (42 ± 13 years of age, 35 women) were included in the final analysis. PIH occurred in 33 (64.7%) hypertensive patients and 19 (36.5%) normotensive patients. In normotensive patients, the area under the receiver operating curve (AUC) in predicting PIH was 0.896 (95% confidence interval [CI]: 0.804–0.987) for IVC-CI, 0.770 (95% CI: 0.633–0.908) for dIVC_max, and 0.868 (95% CI: 0.773–0.963) for dIVC_min. In hypertensive patients, the AUC in predicting PIH was 0.523 (95% CI: 0.354–0.691) for IVC-CI, 0.752 (95% CI: 0.621–0.883) for dIVC_max, and 0.715 (95% CI: 0.571–0.858) for dIVC_min. At the optimal cutoff (1.24 cm), dIVC_max had 54.5% (18/33) sensitivity and 94.4% (17/18) specificity.

Conclusion

In hypertensive patients, IVC-CI is unsuitable for predicting PIH, and dIVC_max is an alternative measure with promising performance.

Clinical trial registration

[http://www.chictr.org.cn/], identifier [ChiCTR2000034853].

Preoperative evaluation and perioperative management of patients undergoing major vascular surgery

Patients undergoing major vascular surgery have an increased risk of perioperative major adverse cardiovascular events (MACE). Accordingly, in this population, it is of particular importance to appropriately risk stratify patients' risk for these complications and optimize risk factors prior to surgical intervention. Comorbidities that portend a higher risk of perioperative MACE include coronary artery disease, heart failure, left-sided valvular heart disease, and significant arrhythmic burden. In this review, we provide a current approach to risk stratification prior to major vascular surgery and describe the strengths and weaknesses of different cardiac risk indices; discuss the role of noninvasive and invasive cardiac testing; and review perioperative pharmacotherapies.

Preoperative Management of Cardiovascular Medications: A Society for Perioperative Assessment and Quality Improvement (SPAQI) Consensus Statement

Cardiovascular conditions such as hypertension, arrhythmias, and heart failure are common in patients undergoing anesthesia for surgical or other procedures. Numerous guidelines from various specialty societies offer variable recommendations for the perioperative management of these medications. The Society for Perioperative Assessment and Quality Improvement identified a need to provide multidisciplinary evidence-based recommendations for preoperative medication management. The society convened a group of 13 members with expertise in perioperative medicine and training in anesthesiology or internal medicine. The aim of this consensus effort is to provide perioperative clinicians with guidance on the management of cardiovascular medications commonly encountered during the preoperative evaluation. We used a modified Delphi process to establish consensus. Twenty-one classes of medications were identified: α-adrenergic receptor antagonists, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, angiotensin receptor-neprilysin inhibitors, β-adrenoceptor blockers, calcium-channel blockers, centrally acting sympatholytic medications, direct-acting vasodilators, loop diuretics, thiazide diuretics, potassium-sparing diuretics, endothelin receptor antagonists, cardiac glycosides, nitrodilators, phosphodiesterase-5 inhibitors, class III antiarrhythmic agents, potassium-channel openers, renin inhibitors, class I antiarrhythmic agents, sodium-channel blockers, and sodium glucose cotransportor-2 inhibitors. We provide recommendations for the management of these medications preoperatively.

Association of Renin-Angiotensin-Aldosterone System Inhibitor Usage Patterns with Mid-Term Amputation Free Survival After Lower Extremity Bypass for Peripheral Arterial Disease

OBJECTIVE

Different renin-angiotensin-aldosterone system inhibitor (RAASI) usage patterns exist among patients undergoing lower extremity bypass (LEB) for peripheral arterial disease (PAD). We studied the association of RAASI usage patterns with LEB outcomes to determine which pattern is associated improved survival after LEB.

METHODS

We evaluated PAD patients who underwent LEB between January 2014 and December 2018 in the Vascular Quality Initiative (VQI) Medicare matched database. Study cohorts included no RAASI use, preoperative RAASI use only, postoperative RAASI use only, and continuous RAASI use both pre-and postoperatively. Logistic and Cox regression was used to adjust for potential confounders. Primary outcome was 2-year amputation free survival (AFS).

RESULTS

Of 19,012 patients included, 1574 (8.3%) were on RAASIs preoperatively only, 1051 (5.5%) postoperatively only, and 8484 (45.2%) continuously. Compared to no RAASI use, isolated preoperative RAASI use was associated with 2.8-fold increased odds of 30-day mortality (aOR, 2.75; 95%CI, 2.15-3.51; P<0.001) whereas continuous RAASI use had 56% lower odds of 30-day mortality (aOR, 0.44; 95%CI, 0.34-0.58; P<0.001). Two-year AFS was 63.2% for no RAASI use and 60.4%, 66.2% and 73.4% for preoperative, postoperative, and continuous RAASI use respectively (P<0.001). While no RAASI use and postoperative RAASI use had comparable adjusted risks of 2-year major amputation or death (aHR, 0.94; 95%CI, 0.83-1.06; P=0.312), this risk was 14% higher for preoperative RAASI use (aHR, 1.14; 95%CI, 1.04-1.26; P=0.006) and 23% lower for continuous RAASI use (aHR, 0.77; 95%CI, 0.72-0.82; P<0.001).

CONCLUSIONS

Isolated preoperative RAASI use was associated with worse 30-day mortality and 2-year AFS while continuous RAASI use was associated with improved 30-day mortality and 2-year AFS. Optimum survival benefit may be derived from continuous RAAS inhibition in the pre- and postoperative periods.

The effect of continuing versus withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers on mortality and major adverse cardiovascular events in hypertensive patients undergoing elective non-cardiac surgery: study protocol for a multi-centric open-label randomised controlled trial

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) are commonly prescribed to patients with hypertension. These drugs are cardioprotective in addition to their blood pressure-lowering effects. However, it is debatable whether hypertensive patients who present for non-cardiac surgery should continue or discontinue these drugs preoperatively. Continuing the drugs entails the risk of perioperative refractory hypotension and/or angioneurotic oedema, while discontinuing the drugs entails the risk of rebound hypertension and myocardial ischaemia. The aim of this study is to evaluate the effect of continuation vs withholding of ACEIs/ARBs on mortality and other major outcomes in hypertensive patients undergoing elective non-cardiac surgery.

METHODS

The continuing vs withholding of ACEIs/ARBs in patients undergoing non-cardiac surgery is a prospective, multi-centric, open-label randomised controlled trial. Two thousand one hundred hypertensive patients receiving ACEIs/ARBs and planned for elective non-cardiac surgery will be enrolled. They will be randomised to either continue the ACEIs/ARBs including on the day of surgery (group A) or to withhold it 24-36 h before surgery (group B). The primary endpoint will be the difference in the composite outcome of all-cause in-hospital/30-day mortality and major adverse cardiovascular and non-cardiovascular events. Secondary endpoints will be to evaluate the differences in perioperative hypotension, angioneurotic oedema, myocardial injury, ICU and hospital stay. The impact of the continuation vs withholding of the ACEIs/ARBs on the incidence of case cancellation will also be studied.

DISCUSSION

The results of this trial should provide sufficient evidence on whether to continue or withhold ACEIs/ARBs before major non-cardiac surgery.

TRIAL REGISTRATION

Clinical Trials Registry of India CTRI/2021/01/030199. Registered on 4 January 2021.

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

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.

Hypotension as a marker or mediator of perioperative organ injury: a narrative review

Perioperative hypotension has been repeatedly associated with organ injury and worse outcome, yet many interventions to reduce morbidity by attempting to avoid or reverse hypotension have floundered. In part, this reflects uncertainty as to what threshold of hypotension is relevant in the perioperative setting. Shifting population-based definitions for hypertension, plus uncertainty regarding individualised norms before surgery, both present major challenges in constructing useful clinical guidelines that may help improve clinical outcomes. Aside from these major pragmatic challenges, a wealth of biological mechanisms that underpin the development of higher blood pressure, particularly with increasing age, suggest that hypotension (however defined) or lower blood pressure per se does not account solely for developing organ injury after major surgery. The mosaic theory of hypertension, first proposed more than 60 yr ago, incorporates multiple, complementary mechanistic pathways through which clinical (macrovascular) attempts to minimise perioperative organ injury may unintentionally subvert protective or adaptive pathways that are fundamental in shaping the integrative host response to injury and inflammation. Consideration of the mosaic framework is critical for a more complete understanding of the perioperative response to acute sterile and infectious inflammation. The largely arbitrary treatment of perioperative blood pressure remains rudimentary in the context of multiple complex adaptive hypertensive endotypes, defined by distinct functional or pathobiological mechanisms, including the regulation of reactive oxygen species, autonomic dysfunction, and inflammation. Developing coherent strategies for the management of perioperative hypotension requires smarter, mechanistically solid interventions delivered by RCTs where observer bias is minimised.

Perioperative hypotension: causes and remedies

Background

Arterial hypotension is common in patients during surgery and those admitted to the intensive care unit (ICU) postoperatively. Perioperative arterial hypotension reportedly significantly affects surgical patients’ outcomes. Blood pressure level is the most crucial factor that influences organ perfusion. Hypoperfusion and organ dysfunction are correlated based on their severity associated with hypotension. As several factors can cause intraoperative hypotension, anesthetists must promptly identify the etiology for appropriate treatment and revert the patient’s hemodynamic profile.

Objectives

This review discusses the concept of perioperative hypotension, identifies its effects in clinical situations, and provides remedies and techniques to predict and avoid its significant consequences.

Conclusions

The primary determinant of organ perfusion is blood pressure. On the other hand, profound hypotension is common in surgical patients and is connected to hypoperfusion and organ failure. Currently, hypotension is addressed once low blood pressure levels are recorded. Early detection of oncoming hypotension or its clinical prediction is of paramount importance in allowing the clinician to treat hypotension and reduce the incidence and length of hypotensive episodes promptly and aggressively.

Intraoperative prediction of postanaesthesia care unit hypotension

BACKGROUND

Postoperative hypotension is associated with adverse outcomes, but intraoperative prediction of postanaesthesia care unit (PACU) hypotension is not routine in anaesthesiology workflow. Although machine learning models may support clinician prediction of PACU hypotension, clinician acceptance of prediction models is poorly understood.

METHODS

We developed a clinically informed gradient boosting machine learning model using preoperative and intraoperative data from 88 446 surgical patients from 2015 to 2019. Nine anaesthesiologists each made 192 predictions of PACU hypotension using a web-based visualisation tool with and without input from the machine learning model. Questionnaires and interviews were analysed using thematic content analysis for model acceptance by anaesthesiologists.

RESULTS

The model predicted PACU hypotension in 17 029 patients (area under the receiver operating characteristic [AUROC] 0.82 [95% confidence interval {CI}: 0.81-0.83] and average precision 0.40 [95% CI: 0.38-0.42]). On a random representative subset of 192 cases, anaesthesiologist performance improved from AUROC 0.67 (95% CI: 0.60-0.73) to AUROC 0.74 (95% CI: 0.68-0.79) with model predictions and information on risk factors. Anaesthesiologists perceived more value and expressed trust in the prediction model for prospective planning, informing PACU handoffs, and drawing attention to unexpected cases of PACU hypotension, but they doubted the model when predictions and associated features were not aligned with clinical judgement. Anaesthesiologists expressed interest in patient-specific thresholds for defining and treating postoperative hypotension.

CONCLUSIONS

The ability of anaesthesiologists to predict PACU hypotension was improved by exposure to machine learning model predictions. Clinicians acknowledged value and trust in machine learning technology. Increasing familiarity with clinical use of model predictions is needed for effective integration into perioperative workflows.

The association between nondipper pattern and perioperative hypertension in patients with controlled hypertension

BACKGROUND

Perioperative hypertension is a frequent complication even in preoperatively normotensive or controlled hypertensive patients and there is a lack of data regarding the effect of nondipping pattern on perioperative hypertension.

OBJECTIVE

In this study, we aimed to investigate the possible effect of nondipping blood pressure pattern on the risk of perioperative hypertension.

MATERIALS AND METHODS

234 hypertensive patients who underwent surgery with general anesthesia were evaluated prospectively. The study enrolled patients with well-controlled preoperative blood pressure. The 24-h ambulatory blood pressure monitoring results were used to classify patients as dippers and nondippers. Perioperative hypertension is defined as a systolic/diastolic arterial blood pressure greater than or equal to 160/90 mmHg or systolic blood pressure elevated by more than 20% from the patient's baseline level for more than 15 min perioperatively.

RESULTS

There were 61 (26%) nondipper patients [mean age: 62.1 ± 7.1 years, 25 (40.9%) men] and 173 (74%) dipper patients [mean age: 61.4 ± 8.1 years, 83 (47.9%) men]. In the nondipper group, perioperative hypertension was observed in 31 (51.3%) patients, whereas in the dipper group, 33 (19.3%) patients experienced a hypertensive attack (P < 0.001). The independent predictors of perioperative hypertension were the presence of the nondipping pattern [odds ratio (OR) 3.084; 95% confidence interval (CI) 1.831-5.195; P < 0.001], the presence of diabetes mellitus (OR 2.059; 95% CI 1.215-3.490; P = 0.007), and the number of drugs (OR 2.317; 95% CI 1.102-5.097; P = 0.027).

CONCLUSION

The frequency of perioperative hypertension was higher in preoperative normotensive and known hypertensive patients who were identified as nondippers. In addition, diabetes mellitus and number of drugs were found to be predictors of perioperative hypertension.

The effect of vasoconstriction on intestinal perfusion is determined by preload dependency: A prospective observational study

BACKGROUND

The effects of vasoconstriction on cardiac stroke volume (SV) and indices of peripheral and intestinal perfusion are insufficiently described.

METHODS

In a non-randomized clinical study, 30 patients undergoing elective rectal surgery were exposed to modulation of preload. The primary endpoint was intestinal perfusion (flux), measured by single-point laser Doppler flowmetry. Secondary endpoints were central cardiovascular variables obtained by the LiDCO rapid monitor, the peripheral perfusion index (PPI) derived from the pulse oximetry signal and muscle (StO₂ ) and cerebral oxygenation (ScO₂ ) determined by near-infrared spectroscopy.

RESULTS

For the whole cohort (n = 30), administration of Phenylephrine during HUT induced a median [IQR] increase in SV by 22% [14-41], p = .003 and in mean arterial pressure (MAP) by 54% [31-62], p < .001, with no change in PPI, StO₂ and ScO₂ or flux. In patients who were preload dependent during HUT (stroke volume variation; SSV >10%; n = 23), administration of phenylephrine increased SV by 29% [12-43], p = .01 and MAP by 54% [33-63], p < .001, followed by an increase in intestinal perfusion flux by 60% [15-289], p = .05, while PPI, StO₂ and ScO₂  remained unchanged. For non-preload dependent patients (SSV <10%; n = 7), no changes in hemodynamic indices were seen besides an increase in MAP by 54% [33-58], p = .002.

CONCLUSION

The reflection of vasoconstrictive modulation of preload in systemic cardiovascular variables and indices of perfusion was dependent on preload responsiveness. Administration of phenylephrine to increase preload did not appear to compromise organ perfusion.

Reported definitions of intraoperative hypotension in adults undergoing non-cardiac surgery under general anaesthesia: a review

Background

Intraoperative hypotension (IOH) during non-cardiac surgery is common and associated with major adverse kidney, neurological and cardiac events and even death. Given that IOH is a modifiable risk factor for the mitigation of postoperative complications, it is imperative to generate a precise definition for IOH to facilitate strategies for avoiding or treating its occurrence. Moreover, a universal and consensus definition of IOH may also facilitate the application of novel and emerging therapeutic interventions in treating IOH. We conducted a review to systematically record the reported definitions of intraoperative hypotension in adults undergoing non-cardiac surgery under general anaesthesia.

Methods

In accordance with Cochrane guidelines, we searched three online databases (OVID [Medline], Embase and Cochrane Library) for all studies published from 1 January 2000 to 6 September 2020. We evaluated the number of studies that reported the absolute or relative threshold values for defining blood pressure. Secondary aims included evaluation of the threshold values for defining IOH, the methodology for accounting for the severity of hypotension, whether the type of surgical procedure influenced the definition of IOH, and whether a study whose definition of IOH aligned with the Perioperative Quality Initiative-3 workgroup (POQI) consensus statement for defining was more likely to be associated with determining an adverse postoperative outcome.

Results

A total of 318 studies were included in the final qualitative synthesis. Most studies (n = 249; 78.3%) used an absolute threshold to define hypotension; 150 (60.5%) reported SBP, 117 (47.2%) reported MAP, and 12 (4.8%) reported diastolic blood pressure (DBP). 126 (39.6%) used a relative threshold to define hypotension. Of the included studies, 153 (48.1%) did not include any duration variable in their definition of hypotension. Among the selected 318 studies 148 (46.5%) studies defined IOH according to the POQI statement. When studies used a “relative blood pressure change” to define IOH, there was a weaker association in detecting adverse postoperative outcomes compared to studies who reported “absolute blood pressure change” (χ²(2) = 10.508, P = 0.005, Cramér’s V = 0.182). When studies used the POQI statement definition of hypotension or defined IOH by values higher than the POQI statement definition there were statistical differences observed between IOH and adverse postoperative outcomes (χ²(1) = 6.581, P = 0.037, Cramér’s V = 0.144). When both the duration of IOH or the numbers of hypotensive epochs were evaluated, we observed a significantly stronger relationship between the definition of IOH use the development of adverse postoperative outcomes. (χ²(1) = 4.860, P = 0.027, Cramér’s V = 0.124).

Conclusions

Most studies defined IOH by absolute or relative changes from baseline values. There are substantial inconsistencies in how IOH was reported. Further, definitions differed across different surgical specialities. Our findings further suggest that IOH should be defined using the absolute values stated in the POQI statement i.e., MAP < 60–70 mmHg or SBP < 100 mmHg. Finally, the number of hypotensive epochs or time-weighted duration of IOH should also be reported.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01605-9.

Continuing versus withholding angiotensin receptor blocker (ARB)/calcium channel blocker (CCB) combination tablets during perioperative periods in patients undergoing minor surgery: a single-blinded randomized controlled trial

Purpose

This trial was conducted to compare effects of continuing versus withholding single-pill combination tablets consisting of angiotensin receptor blockers (ARBs) and calcium channel blockers (CCBs) on perioperative hemodynamics and clinical outcomes.

Methods

Patients undergoing minor abdominal or urological surgery (n = 106) were randomly assigned to Group C, in which ARB/CCB combination tablets were continued until surgery, or Group W, in which they were withheld within 24 h of surgery. Perioperative hemodynamics and clinical outcomes were compared between the Groups.

Results

The incidence of hypotension during anesthesia requiring repeated treatment with vasoconstrictors was higher in Group C than Group W (p = 0.0052). Blood pressure during anesthesia was generally lower in Group C than Group W (p < 0.05) despite significantly more doses of ephedrine and phenylephrine administrated in Group C (p = 0.0246 and p = 0.0327, respectively). The incidence of postoperative hypertension did not differ between Groups (p = 0.3793). Estimated glomerular filtration rate (eGFR) on the preoperative day did not differ between Groups (p = 0.7045), while eGFR was slightly lower in Group C than Group W on the first and third postoperative days (p = 0.0400 and p = 0.0088, respectively), although clinically relevant acute kidney injury did not develop.

Conclusions

Continuing ARB/CCB combination tablets preoperatively in patients undergoing minor surgery increased the incidence of hypotension during anesthesia, increased requirements of vasoconstrictors to treat hypotension, and might deteriorate postoperative renal function, albeit slightly. These results suggest that withholding ARB/CCB tablets preoperatively is preferable to continuing them.

Clinical trial registration

This trial is registered with the Japan Registry of Clinical Trials (jRCT) at Japanese Ministry of Health, Labour, and Welfare (Trial ID: jRCT1031190027).