IntroductionIntraoperative hypotension is associated with adverse postoperative outcomes; however these findings are supported only by observational studies. The aim of this meta-analysis of randomised trials was to compare the postoperative effects permissive management with targeted management of intraoperative blood pressure.MethodsWe searched PubMed, Cochrane, and Embase up to June 2023 for studies comparing permissive (mean arterial pressure ≤60 mm Hg) with targeted (mean arterial pressure >60 mm Hg) intraoperative blood pressure management. Primary outcome was all-cause mortality at the longest follow-up available. Secondary outcomes were atrial fibrillation, myocardial infarction, acute kidney injury, delirium, stroke, number of patients requiring transfusion, time on mechanical ventilation, and length of hospital stay.ResultsWe included 10 randomised trials including a total of 9359 patients. Mortality was similar between permissive and targeted blood pressure management groups (89/4644 [1.9%] vs 99/4643 [2.1%], odds ratio 0.88, 95% confidence interval [CI], 0.65–1.18, P=0.38, I2=0% with nine studies included). Atrial fibrillation (102/3896 [2.6%] vs 130/3887 [3.3%] odds ratio 0.71, 95% CI 0.53–0.96, P=0.03, I2=0%), and length of hospital stay (mean difference –0.20 days, 95% CI −0.26 to −0.13, P<0.001, I2=0%) were reduced in the permissive management group. No significant differences were found in subgroup analysis for cardiac and noncardiac surgery.ConclusionPooled randomised evidence shows that a target intraoperative mean arterial pressure ≤60 mm Hg is not associated with increased mortality; nevertheless it is surprisingly associated with a reduced rate of atrial fibrillation and of length of hospital stay.Systematic review protocolPROSPERO CRD42023393725. 

Intraoperative hypotension and postoperative outcomes: a meta-analysis of randomised trials.

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.

/pdf/provisional-decision-making-for-perioperative-blood-pressure-3mvrltli.pdf

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

Abstract Background Renal hypoperfusion is one of the most common causes of acute kidney injury (AKI), especially in shock and perioperative patients. An optimal blood pressure (BP) target to prevent AKI remains undetermined. We conducted a systematic review and meta-analysis of available randomized clinical trial (RCT) results to address this knowledge gap. Methods From inception to May 13, 2022, we searched Ovid Medline, EMBASE, Cochrane Library, SCOPUS, clinicaltrials.gov, and WHO ICTRP for RCTs comparing higher BP target versus normotension in hemodynamically unstable patients (shock, post-cardiac arrest, or surgery patients). The outcomes of interest were post-intervention AKI rate and renal replacement therapy (RRT) rate. Two investigators independently screened the citations and reviewed the full texts for eligible studies according to a predefined form. Results Twelve trials were included, enrolling a total of 5759 participants, with shock, non-cardiac, and cardiac surgery patients accounting for 3282 (57.0%), 1687 (29.3%) and 790 (13.7%) patients, respectively. Compared to lower mean arterial blood pressure (MAP) targets that served as normotension, targeting higher MAP had no significant effect on AKI rates in shock (RR [95% CI] = 1.10 [0.93, 1.29]), in cardiac-surgery (RR [95% CI] = 0.87 [0.73, 1.03]) and non-cardiac surgery patients (RR [95% CI] = 1.25 [0.98, 1.60]) using random-effects meta-analyses. In shock patients with premorbid hypertension, however, targeting MAP above 70 mmHg resulted in significantly lower RRT risks, RR [95%CI] = 1.20 [1.03, 1.41], p &lt; 0.05. Conclusions Targeting a higher MAP in shock or perioperative patients may not be superior to normotension, except in shock patients with premorbid hypertension. Further studies are needed to assess the effects of a high MAP target to preventing AKI in hypertensive patients across common settings of hemodynamic instability. Trial registration This systematic review has been registered on PROSPERO ( CRD42021286203 ) on November 19, 2021, prior to data extraction and analysis. 

/pdf/higher-blood-pressure-versus-normotension-targets-to-prevent-2hqn76mj.pdf

Higher blood pressure versus normotension targets to prevent acute kidney injury: a systematic review and meta-regression of randomized controlled trials

OBJECTIVES
Hypotension is associated with adverse outcomes in critically ill and perioperative patients. However, these assumptions are supported by observational studies. This meta-analysis of randomized controlled trials aims to compare the impact of lower versus higher blood pressure targets on mortality.


DATA SOURCES
We searched PubMed, Cochrane, and Scholar from inception to February 10, 2024.


STUDY SELECTION
Randomized trials comparing lower versus higher blood pressure targets in the management of critically ill and perioperative settings.


DATA EXTRACTION
The primary outcome was all-cause mortality at the longest follow-up available. This review was registered in the Prospective International Register of Systematic Reviews, CRD42023452928.


DATA SYNTHESIS
Of 2940 studies identified by the search string, 28 (12 in critically ill and 16 in perioperative settings) were included totaling 15,672 patients. Patients in the low blood pressure target group had lower mortality (23 studies included: 1019/7679 [13.3%] vs. 1103/7649 [14.4%]; relative risk 0.93; 95% CI, 0.87-0.99; p = 0.03; I2 = 0%). This corresponded to a 97.4% probability of any increase in mortality with a Bayesian approach. These findings were mainly driven by studies performed in the ICU setting and with treatment lasting more than 24 hours; however, the magnitude and direction of the results were similar in the majority of sensitivity analyses including the analysis restricted to low risk of bias studies. We also observed a lower rate of atrial fibrillation and fewer patients requiring transfusion in low-pressure target groups. No differences were found in the other secondary outcomes.


CONCLUSIONS
Based on pooled randomized trial evidence, a lower compared with a higher blood pressure target results in a reduction of mortality, atrial fibrillation, and transfusion requirements. Lower blood pressure targets may be beneficial but there is ongoing uncertainty. However, the present meta-analysis does not confirm previous findings and recommendations. These results might inform future guidelines and promote the study of the concept of protective hemodynamics.

Low Versus High Blood Pressure Targets in Critically Ill and Surgical Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Bolther, Maria; Henriksen, Jeppe; Holmberg, Mathias J.; Granfeldt, Asger; Andersen, Lars W. Author Information 

Blood pressure targets during general anaesthesia for noncardiac surgery

Many believe that blood pressure management during cardiac surgery is associated with postoperative outcomes. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to determine the impact of high compared with low intraoperative blood pressure targets on postoperative morbidity and mortality in adults undergoing cardiac surgery on cardiopulmonary bypass (CPB). Our primary objective was to inform the design of a future large RCT.We searched MEDLINE, EMBASE, Web of Science, CINAHL, and CENTRAL for RCTs comparing high with low intraoperative blood pressure targets in adult patients undergoing any cardiac surgical procedure on CPB. We screened reference lists, grey literature, and conference proceedings.We included eight RCTs (N =1,116 participants); all examined the effect of blood pressure management only during the CPB. Trial definitions of high compared with low blood pressure varied and, in some, there was a discrepancy between the target and achieved mean arterial pressure. We observed no difference in delirium, cognitive decline, stroke, acute kidney injury, or mortality between high and low blood pressure targets (very-low to low quality evidence). Higher blood pressure targets may have increased the risk of requiring a blood transfusion (three trials; n = 456 participants; relative risk, 1.4; 95% confidence interval, 1.1 to 1.9; P = 0.01; moderate quality evidence) but this finding was based on a small number of trials.Individual trial definitions of high and low blood pressure targets varied, limiting inferences. The effect of high (compared with low) blood pressure targets on other morbidity and mortality after cardiac surgery remains unclear because of limitations with the body of existing evidence. Research to determine the optimal management of blood pressure during cardiac surgery is required.PROSPERO (CRD42020177376); registered: 5 July 2020.RéSUMé: OBJECTIF: Pour beaucoup, la prise en charge de la pression artérielle pendant la chirurgie cardiaque serait associée aux issues postopératoires. Nous avons réalisé une revue systématique et une méta-analyse d’études randomisées contrôlées (ERC) afin de déterminer l’impact de cibles peropératoires de pression artérielle élevées par rapport à des cibles basses sur la morbidité et la mortalité postopératoires d’adultes bénéficiant d’une chirurgie cardiaque sous circulation extracorporelle (CEC). Notre objectif principal était d’orienter la conception d’une future ERC d’envergure.Nous avons analysé les bases de données MEDLINE, EMBASE, Web of Science, CINAHL et CENTRAL afin d’en tirer les ERC comparant des cibles de pression artérielle peropératoire élevées à des cibles basses chez des patients adultes bénéficiant d’une intervention chirurgicale cardiaque sous CEC. Nous avons passé au crible les listes de références, la littérature grise et les travaux de congrès.Nous avons inclus huit ERC (N = 1116 participants); toutes les études ont examiné l’effet de la prise en charge de la pression artérielle uniquement pendant la CEC. Les définitions d’une pression artérielle élevée ou basse variaient d’une étude à l’autre et, dans certains cas, un écart a été noté entre la pression artérielle cible et la pression artérielle moyenne atteinte. Nous n’avons observé aucune différence dans les taux de delirium, de déclin cognitif, d’accident vasculaire cérébral, d’insuffisance rénale aiguë ou de mortalité entre les cibles de pression artérielle élevée et basse (données probantes de qualité très faible à faible). Des cibles de pression artérielle plus élevées pourraient avoir augmenté le risque de transfusion sanguine (trois études; n = 456 participants; risque relatif, 1,4; intervalle de confiance à 95 %, 1,1 à 1,9; P = 0,01; données probantes de qualité modérée), mais ce résultat se fondait sur un petit nombre d’études.Les définitions individuelles des cibles d’hypertension et d’hypotension artérielle variaient, ce qui a limité les inférences. L’effet de cibles de pression artérielle élevée (par rapport à une pression artérielle basse) sur d’autres mesures de la morbidité et de la mortalité après une chirurgie cardiaque demeure incertain en raison des limites de l’ensemble des données probantes existantes. Des recherches visant à déterminer la prise en charge optimale de la pression artérielle pendant la chirurgie cardiaque sont nécessaires. ENREGISTREMENT DE L’éTUDE: PROSPERO (CRD42020177376); enregistrée le 5 juillet 2020. 

/pdf/morbidity-and-mortality-in-patients-managed-with-high-24aq70uc.pdf

Morbidity and mortality in patients managed with high compared with low blood pressure targets during on-pump cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

/pdf/correction-to-morbidity-and-mortality-in-patients-managed-1gidlgyo.pdf

Correction to: Morbidity and mortality in patients managed with high compared with low blood pressure targets during on-pump cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

For patients with mechanical aortic valves, guideline recommended INR targets range from 2.0 to 3.5, depending on thromboembolic risk factors. Supporting data is largely historical and of low quality. We aimed to characterize clinicians’ practices around INR targets for these patients and perceptions of evidence supporting these recommendations. A 33-question web-based survey was sent to 75 cardiologists, cardiac surgeons, and thrombosis specialists globally. We inquired about anticoagulation practices for patients with mechanical aortic valves, perceptions of guideline recommendations, and interest in participating in a randomized controlled trial comparing lower and higher INR targets in these patients. Of 55 respondents (73% response rate), 78% worked in academic hospitals. In patients with mechanical aortic valve and no additional thromboembolic risk factors, 80% targeted an INR of 2.5. Among patients with additional thromboembolic risk factors, 48% targeted an INR of 2.5, while 44% targeted an INR of 3.0. Additionally, 57% of respondents believed that evidence for the guidelines was up to date, and 53% believed that it applied to bi-leaflet valves. However, 57% of respondents said that the evidence was not high quality. Lastly, 66% of respondents would accept a higher thromboembolic risk to reduce risk of major bleeding; 86% were willing to randomize patients with mechanical aortic valve to a target INR of 2.0 if they had no thromboembolic risk factors. Clinicians target different INRs for patients with mechanical aortic valves; their perception of the evidence and guidelines varies. Of respondents, 86% would randomize patients to lower INR targets. 

Anticoagulation for mechanical aortic valves: An international survey of current practice patterns and perceptions

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Morbidity and mortality in patients managed with high compared with low blood pressure targets during on-pump cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

Correction to: Morbidity and mortality in patients managed with high compared with low blood pressure targets during on-pump cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

Anticoagulation for mechanical aortic valves: An international survey of current practice patterns and perceptions