Identification of the haemoglobin level associated with a lower risk of complications after total hip and knee arthroplasty.

BACKGROUND: Preoperative anaemia is associated with poor outcomes in surgical patients, but the preoperative haemoglobin cut-off that determines lower morbidity in total knee arthroplasty (TKA) and total hip arthroplasty (THA) is not well established. METHODS: Planned secondary analysis of data collected during a multicentre cohort study of patients undergoing THA and TKA in 131 Spanish hospitals during a single 2-month recruitment period. Anaemia was defined as haemoglobin <12 g dl-1 for females and < 13 g dl-1 for males. The primary outcome was the number of patients with 30-day in-hospital postoperative complications according to European Perioperative Clinical Outcome definitions and specific surgical TKA and THA complications. Secondary outcomes included the number of patients with 30-day moderate-to-severe complications, red blood cell transfusion, mortality, and length of hospital stay. Binary logistic regression models were constructed to assess association between preoperative Hb concentrations and postoperative complications, and variables significantly associated with the outcome were included in the multivariate model. The study sample was divided into 11 groups based on preoperative Hb values in an effort to identify the threshold at which increased postoperative complications occurred. RESULTS: A total of 6099 patients were included in the analysis (3818 THA and 2281 TKA), of whom 8.8% were anaemic. Patients with preoperative anaemia were more likely to suffer overall complications (111/539, 20.6% vs. 563/5560, 10.1%, p < .001) and moderate-to-severe complications (67/539, 12.4% vs. 284/5560, 5.1%, p < .001). Multivariable analysis showed preoperative haemoglobin ≥14 g dl-1 was associated with fewer postoperative complications. CONCLUSION: Preoperative haemoglobin ≥14 g dl-1 is associated with a lower risk of postoperative complications in patients undergoing primary TKA and THA.

Association between enrollment in an enhanced recovery program for colorectal cancer surgery and long-term recurrence and survival.

INTRODUCTION: Enhanced Recovery After Surgery (ERAS) programs have been shown to minimize the surgical inflammatory response in colorectal cancer. Our objective was to determine the association between an ERAS program for colorectal cancer surgery and oncologic recurrence and survival. METHODS: A before-after intervention study was designed, including patients who underwent colorectal cancer surgery between November 2010 and March 2016. Cox hazard regression analysis was performed per cumulative year of follow-up to evaluate the association between ERAS program exposure and overall survival. Subgroup analysis was performed by cancer stage (low [I/II] vs. advanced [III/IV]). RESULTS: In total, 646 patients were included, of which 339 were pre-ERAS and 307 were ERAS. Our overall median compliance rate with ERAS interventions was 90% (interquartile range: 85%-95%). Overall survival rates were higher in the ERAS group within the first 2 years after surgery (89.2% vs.  83.2%; p = 0.04). Multivariable analysis revealed that the ERAS enrollment was associated with a significantly lower risk in 5-year oncologic recurrence (adjusted hazard ratio [aHR]: 0.55; 95% confidence interval [CI]: 0.33-0.94; p = 0.03) and higher 3-year survival (aHR: 0.55; 95% CI: 0.33-0.93; p = 0.03) among patients with advanced cancer stage compared to pre-ERAS counterparts. CONCLUSIONS: Patients with advanced colorectal cancer were less likely to suffer oncologic recurrence when managed during the ERAS period.

Enhanced Recovery After Surgery (ERAS) in Surgical Oncology.

PURPOSE OF THE REVIEW: The objective of this review is to address the rationale behind the application of the Enhanced Recovery After Surgery (ERAS) protocols that could improve oncologic outcomes in adult patients undergoing major surgery. RECENT FINDINGS: The implementation of ERAS protocols has been associated with fewer postoperative complications as well as decreased return to intended oncologic treatment (RIOT). However, few studies have analyzed the influence of the application of ERAS protocols and long-term oncologic outcomes, although some of its individual elements have been associated with improvements in oncologic outcomes, including overall survival and disease-free survival. Targeted long-term follow-up studies in specific oncologic procedures are required to determine whether ERAS application results in improved oncologic outcomes.

Early Return to Intended Oncologic Therapy after implementation of an Enhanced Recovery After Surgery pathway for gastric cancer surgery.

PURPOSE: Time to initiation and completion of adjuvant therapy are critical to improve postoperative oncologic outcomes. This study aims to determine whether an Enhanced Recovery After Surgery (ERAS) pathway for gastric cancer surgery promotes early Return to Intended Oncologic Therapy (RIOT). METHODS: This is a before-after intervention study including patients with gastric adenocarcinoma who underwent surgery from January 2016 to January 2021. Two periods were denoted based upon the implementation date of our institutional ERAS pathway (June 2018). Our primary outcome was time to RIOT after surgery. Hodges-Lehmann analysis was used to estimate median differences of non-parametric outcomes. RESULTS: Seventy patients with gastric adenocarcinoma were included (35 in pre-ERAS period and 35 in post-ERAS period). Fourteen of the pre-ERAS and twenty-two patients of the post-ERAS period received adjuvant therapy. Time to RIOT was reduced in the post-ERAS period (median 39 days, IQR 31-49) by 12 days (95% CI 3-14 days, p = 0.01) compared to the pre-ERAS period (median 51 days, IQR 42-62). Length of hospital stay (LOS) was lower in the ERAS group (6 days, IQR 5-11 vs 10 days, IQR 8-13, p < 0.01). CONCLUSION: Our institutional ERAS pathway for gastric cancer surgery was associated with earlier RIOT and shorter LOS.

Safety and efficacy of tetrastarches in surgery and trauma: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Hydroxyethyl starch (HES) 130 is a frequently used fluid to replace intravascular losses during surgery or trauma. In the past years, several trials performed in critically ill patients have raised questions regarding the safety of this product. Our aim in this meta-analysis was to evaluate the safety and efficacy of 6% HES during surgery and in trauma. METHODS: This systematic review and meta-analysis was registered at PROSPERO (CRD42018100379). We included 85 fully published articles from 1980 to June 2018 according to the protocol and three additional recent articles up to June 2020 in English, French, German, and Spanish reporting on prospective, randomised, and controlled clinical trials applying volume therapy with HES 130/0.4 or HES 130/0.42, including combinations with crystalloids, to patients undergoing surgery. Comparators were albumin, gelatin, and crystalloids only. A meta-analysis could not be performed for the two trauma studies as there was only one study that reported data on endpoints of interest. RESULTS: Surgical patients treated with HES had lower postoperative serum creatinine (P<0.001) and showed no differences in renal dysfunction, renal failure, or renal replacement therapy. Although there was practically no further difference in the colloids albumin or gelatin, the use of HES improved haemodynamic stability, reduced need for vasopressors (P<0.001), and decreased length of hospital stay (P<0.001) compared with the use of crystalloids alone. CONCLUSIONS: HES was shown to be safe and efficacious in the perioperative setting. Results of the present meta-analysis suggest that when used with adequate indication, a combination of intravenous fluid therapy with crystalloids and volume replacement with HES as colloid has clinically beneficial effects over using crystalloids only.

Observational study on fluid therapy management in surgical adult patients.

BACKGROUND: Perioperative fluid therapy management is changing due to the incorporation of different fluids, surgical techniques, and minimally invasive monitoring systems. The objective of this study was to explore fluid therapy management during the perioperative period in our country. METHODS: We designed the Fluid Day study as a cross-sectional, multicentre, observational study. The study was performed in 131 Spanish hospitals in February 2019. We included adult patients undergoing general anaesthesia for either elective or non-elective surgery. Demographic variables were recorded, as well as the type and total volume of fluid administered during the perioperative period and the monitorization used. To perform the analysis, patients were categorized by risk group. RESULTS: We recruited 7291 patients, 6314 of which were included in the analysis; 1541 (24.4%) patients underwent high-risk surgery, 1497 (23. 7%) were high risk patients, and 554 (8.7%) were high-risk patients and underwent high-risk surgery; 98% patients received crystalloids (80% balanced solutions); intraoperative colloids were used in 466 patients (7.51%). The hourly intraoperative volume in mL/kg/h and the median [Q1; Q3] administered volume (mL/kg) were, respectively, 6.67 [3.83; 8.17] ml/Kg/h and 13.9 [9.52;5.20] ml/Kg in low-risk patients undergoing low- or intermediate-risk surgery, 6 [4.04; 9.08] ml/Kg/h and 15.7 [10.4;24.5] ml/Kg in high- risk patients undergoing low or intermediate-risk surgery, 6.41 [4.36; 9.33] ml/Kg/h and 20.2 [13.3;32.4] ml/Kg in low-risk patients undergoing high-risk surgery, and 5.46 [3.83; 8.17] ml/Kg/h and 22.7[14.1;40.9] ml/Kg in high-risk patients undergoing high- risk surgery . We used advanced fluid monitoring strategies in 5% of patients in the intraoperative period and in 10% in the postoperative period. CONCLUSIONS: The most widely used fluid was balanced crystalloids. Colloids were used in a small number of patients. Hourly surgery volume tended to be more restrictive in high-risk patients but confirms a high degree of variation in the perioperatively administered volume. Scarce monitorization was observed in fluid therapy management. TRIAL REGISTRATION: Clinical Trials: NCT03630744.

Risk factors for acute kidney injury in an enhanced recovery pathway for colorectal surgery.

PURPOSES: Enhanced recovery pathways (ERPs) have been disseminated worldwide to improve the perioperative patient outcomes while lowering direct healthcare costs. Recent evidence has revealed a potential association between ERPs for colorectal surgery and acute kidney injury (AKI). We, therefore, sought to identify the risk factors associated with postoperative AKI among patients in an ERP for colorectal surgery. METHODS: We analyzed the data resulting from a large multicenter, prospective cohort study of patients in an ERP for colorectal surgery. A multivariable analysis was performed to identify factors independently associated with postoperative AKI. The receiver operating characteristic (ROC) curves and contour representations were plotted for the diagnostic prediction analysis. RESULTS: Among those patients included in the analysis (n = 1652), the overall incidence of postoperative AKI was 7.7% (95% CI 6.5-9.1%). After adjustment, the independent risk factors for AKI included age > 60 (OR 1.03, 95% CI 1.01-1.05), male gender (OR 2.33, 95% CI 1.36-4.02), ASA III-IV (OR 2.43, 95% CI 1.39-4.26), CKD (OR 2.45, 95% CI 1.42-4.23), open surgical approach (OR 2.62, 95% CI 1.63-4.21) and serum albumin < 3.5 g/dL (OR 1.68, 95% CI 1.02-2.79). An ROC analysis revealed that the composite of albumin, creatinine and age was a strong predictor of postoperative AKI [area under the curve (AUC) 0.756; 95% CI 0.705-0.808]. CONCLUSION: Postoperative AKI is common in the setting of ERPs for colorectal surgery and it is associated with a poor clinical outcome. Of those characteristics associated with postoperative AKI, one modifiable factor is a low preoperative albumin level. Screening for malnourished patients or optimizing the nutritional status may be a useful preoperative intervention to prevent postoperative AKI and associated complications.

Hypotension prediction index guided goal-directed therapy to reduce postoperative acute kidney injury during major abdominal surgery: study protocol for a multicenter randomized controlled clinical trial.

BACKGROUND: Acute kidney injury (AKI) is a significant postoperative complication associated with increased mortality and hospital costs. Hemodynamic strategies, such as goal-directed therapy, might reduce AKI risk. Predicting and proactively managing intraoperative hypotension may be helpful. This trial aims to investigate if a preemptive hemodynamic strategy guided by the hypotension prediction index (HPI) can decrease the incidence of moderate-to-severe AKI within 30 days following major elective abdominal surgery. METHODS: This is an open-label, controlled, multicenter, randomized clinical trial that involves daily patient follow-up until hospital discharge. Inclusion criteria are patients aged over 65 and/or categorized as ASA III or IV physical status, undergoing major elective abdominal surgery (general, urological, or gynecological procedures) via laparoscopic or open approach under general or combined anesthesia. INTERVENTION: In the intervention group, hemodynamic management will be based on the HPI and the advanced functional hemodynamic variables provided by the Hemosphere platform and the AcumenIQ® sensor (Edwards Lifesciences). The primary outcome is the incidence of moderate-to-severe AKI within 7 days post-surgery. Secondary outcomes include postoperative complications and 30-day mortality. DISCUSSION: This study explores the potential of HPI-guided hemodynamic management in reducing AKI after major elective abdominal surgery, with implications for postoperative outcomes and patient care. TRIAL REGISTRATION: ClinicalTrials.gov NCT05569265. Registered on October 6, 2022.

Role of Crystalloids in the Perioperative Setting: From Basics to Clinical Applications and Enhanced Recovery Protocols.

Perioperative fluid management, a critical aspect of major surgeries, is characterized by pronounced stress responses, altered capillary permeability, and significant fluid shifts. Recognized as a cornerstone of enhanced recovery protocols, effective perioperative fluid management is crucial for optimizing patient recovery and preventing postoperative complications, especially in high-risk patients. The scientific literature has extensively investigated various fluid infusion regimens, but recent publications indicate that not only the volume but also the type of fluid infused significantly influences surgical outcomes. Adequate fluid therapy prescription requires a thorough understanding of the physiological and biochemical principles that govern the body's internal environment and the potential perioperative alterations that may arise. Recently published clinical trials have questioned the safety of synthetic colloids, widely used in the surgical field. A new clinical scenario has arisen in which crystalloids could play a pivotal role in perioperative fluid therapy. This review aims to offer evidence-based clinical principles for prescribing fluid therapy tailored to the patient's physiology during the perioperative period. The approach combines these principles with current recommendations for enhanced recovery programs for surgical patients, grounded in physiological and biochemical principles.

Intraoperative hypotension when using hypotension prediction index software during major noncardiac surgery: a European multicentre prospective observational registry (EU HYPROTECT).

Background: Intraoperative hypotension is associated with organ injury. Current intraoperative arterial pressure management is mainly reactive. Predictive haemodynamic monitoring may help clinicians reduce intraoperative hypotension. The Acumen™ Hypotension Prediction Index software (HPI-software) (Edwards Lifesciences, Irvine, CA, USA) was developed to predict hypotension. We built up the European multicentre, prospective, observational EU HYPROTECT Registry to describe the incidence, duration, and severity of intraoperative hypotension when using HPI-software monitoring in patients having noncardiac surgery. Methods: We enrolled 749 patients having elective major noncardiac surgery in 12 medical centres in five European countries. Patients were monitored using the HPI-software. We quantified hypotension using the time-weighted average MAP <65 mm Hg (primary endpoint), the proportion of patients with at least one ≥1 min episode of a MAP <65 mm Hg, the number of ≥1 min episodes of a MAP <65 mm Hg, and duration patients spent below a MAP of 65 mm Hg. Results: We included 702 patients in the final analysis. The median time-weighted average MAP <65 mm Hg was 0.03 (0.00-0.20) mm Hg. In addition, 285 patients (41%) had no ≥1 min episode of a MAP <65 mm Hg; 417 patients (59%) had at least one. The median number of ≥1 min episodes of a MAP <65 mm Hg was 1 (0-3). Patients spent a median of 2 (0-9) min below a MAP of 65 mm Hg. Conclusions: The median time-weighted average MAP <65 mm Hg was very low in patients in this registry. This suggests that using HPI-software monitoring may help reduce the duration and severity of intraoperative hypotension in patients having noncardiac surgery.

Postoperative Critical Care Admission Was Not Associated with Improved Postoperative Outcomes in Elective Colorectal Surgery: Secondary Analysis Of POWER Trial.

BACKGROUND: The efficacy of routine admission of high-risk patients to a critical care unit after surgery is not clear. The aim of our study was to investigate the association between critical care admission after scheduled colorectal surgery and postoperative complications, 30-day mortality, and length of stay in hospital. METHODS: A pre-defined secondary substudy of POWER study was performed. POWER study was a prospective multicenter observational study of patients undergoing elective primary colorectal surgery during a single period of two months of recruitment between September and December 2017. RESULTS: A total of 2084 patients from 80 Spanish hospitals were included, of which 722 (34.6%) were admitted to critical care unit (CCU) after elective surgery. After adjusting for confounding factors in the multivariate analysis, postoperative CCU admission was independently associated with a higher incidence of moderate-to-severe postoperative complications (adjusted OR 1.951, 95% CI 1.570, 2.425; p < 0.001). Regarding secondary outcomes, postoperative critical care admission was independently associated with higher 30-day mortality (adjusted OR 6.736; 95% CI 2.507, 18.101; p < 0.001) and independently associated with an increased hospital length of stay (adjusted OR 1.143, 95% CI 1.112, 1.175; p < 0.001). CONCLUSIONS: Direct admission to CCU after scheduled colorectal surgery was not associated with a reduction in moderate-to-severe postoperative complications.

Biomarker-guided intervention to prevent acute kidney injury after major surgery (BigpAK-2 trial): study protocol for an international, prospective, randomised controlled multicentre trial.

INTRODUCTION: Previous studies demonstrated that the implementation of the Kidney Disease Improving Global Outcomes (KDIGO) guideline-based bundle, consisting of different supportive measures in patients at high risk for acute kidney injury (AKI), might reduce rate and severity of AKI after surgery. However, the effects of the care bundle in broader population of patients undergoing surgery require confirmation. METHODS AND ANALYSIS: The BigpAK-2 trial is an international, randomised, controlled, multicentre trial. The trial aims to enrol 1302 patients undergoing major surgery who are subsequently admitted to the intensive care or high dependency unit and are at high-risk for postoperative AKI as identified by urinary biomarkers (tissue inhibitor of metalloproteinases 2*insulin like growth factor binding protein 7 (TIMP-2)*IGFBP7)). Eligible patients will be randomised to receive either standard of care (control) or a KDIGO-based AKI care bundle (intervention). The primary endpoint is the incidence of moderate or severe AKI (stage 2 or 3) within 72 hours after surgery, according to the KDIGO 2012 criteria. Secondary endpoints include adherence to the KDIGO care bundle, occurrence and severity of any stage of AKI, change in biomarker values during 12 hours after initial measurement of (TIMP-2)*(IGFBP7), number of free days of mechanical ventilation and vasopressors, need for renal replacement therapy (RRT), duration of RRT, renal recovery, 30-day and 60-day mortality, intensive care unit length-of-stay and hospital length-of-stay and major adverse kidney events. An add-on study will investigate blood and urine samples from recruited patients for immunological functions and kidney damage. ETHICS AND DISSEMINATION: The BigpAK-2 trial was approved by the Ethics Committee of the Medical Faculty of the University of Münster and subsequently by the corresponding Ethics Committee of the participating sites. A study amendment was approved subsequently. In the UK, the trial was adopted as an NIHR portfolio study. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and will guide patient care and further research. TRIAL REGISTRATION NUMBER: NCT04647396.

Association between use of enhanced recovery after surgery protocols and postoperative complications after gastric surgery for cancer (POWER 4): a nationwide, prospective multicentre study.

INTRODUCTION: The effectiveness of the Enhanced Recovery After Surgery (ERAS) protocols in gastric cancer surgery remains controversial. METHODS: Multicentre prospective cohort study of adult patients undergoing surgery for gastric cancer. Adherence with 22 individual components of ERAS pathways were assessed in all patients, regardless of whether they were treated in a self-designed ERAS centre. Each centre had a three-month recruitment period between October 2019 and September 2020. The primary outcome was moderate-to-severe postoperative complications within 30 days after surgery. Secondary outcomes were overall postoperative complications, adherence to the ERAS pathway, 30 day-mortality and hospital length of stay (LOS). RESULTS: A total of 743 patients in 72 Spanish hospitals were included, 211 of them (28.4 %) from self-declared ERAS centres. A total of 245 patients (33 %) experienced postoperative complications, graded as moderate-to-severe complications in 172 patients (23.1 %). There were no differences in the incidence of moderate-to-severe complications (22.3% vs. 23.5%; OR, 0.92 (95% CI, 0.59 to 1.41); P = 0.068), or overall postoperative complications between the self-declared ERAS and non-ERAS groups (33.6% vs. 32.7%; OR, 1.05 (95 % CI, 0.70 to 1.56); P = 0.825). The overall rate of adherence to the ERAS pathway was 52% [IQR 45 to 60]. There were no differences in postoperative outcomes between higher (Q1, > 60 %) and lower (Q4, ≤ 45 %) ERAS adherence quartiles. CONCLUSIONS: Neither the partial application of perioperative ERAS measures nor treatment in self-designated ERAS centres improved postoperative outcomes in patients undergoing gastric surgery for cancer. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03865810.

Effect of goal-directed haemodynamic therapy guided by non-invasive monitoring on perioperative complications in elderly hip fracture patients within an enhanced recovery pathway.

BACKGROUND: Goal-directed haemodynamic therapy (GDHT) has been shown to reduce morbidity and mortality in high-risk surgical patients. However, there is little evidence of its efficacy in patients undergoing hip fracture surgery. This study aims to evaluate the effect of GDHT guided by non-invasive haemodynamic monitoring on perioperative complications in patients undergoing hip fracture surgery. METHODS: Patients > 64 years undergoing hip fracture surgery within an enhanced recovery pathway (ERP) were enrolled in this single-centre, non-randomized, intervention study with a historical control group and 12-month follow-up. Exclusion criteria were patients with pathological fractures, traffic-related fractures and refractures. Control group (CG) patients received standard care treatment. Intervention group (IG) patients received a GDHT protocol based on achieving an optimal stroke volume, in addition to a systolic blood pressure > 90 mmHg and an individualized cardiac index. No changes were made between groups in the ERP during the study period. Primary outcome was percentage of patients who developed intraoperative haemodynamic instability. Secondary outcomes were intraoperative arrhythmias, postoperative complications (cardiovascular, respiratory, infectious and renal complications), administered fluids, vasopressor requirements, perioperative transfusion, length of hospital stay, readmission and 1-year survival. RESULTS: In total, 551 patients (CG=272; IG=279) were included. Intraoperative haemodynamic instability was lower in the IG (37.5% vs 28.0%; p=0.017). GDHT patients had fewer postoperative cardiovascular (18.8% vs 7.2%; p < 0.001), respiratory (15.1% vs 3.6%; p<0.001) and infectious complications (21% vs 3.9%; p<0.001) but not renal (12.1% vs 33.7%; p<0.001). IG patients had less vasopressor requirements (25.5% vs 39.7%; p<0.001) and received less fluids [2.600 ml (IQR 1700 to 2700) vs 850 ml (IQR 750 to 1050); p=0.001] than control group. Fewer patients required transfusion in GDHT group (73.5% vs 44.4%; p<0.001). For IG patients, median length of hospital stay was shorter [11 days (IQR 8 to 16) vs 8 days; (IQR 6 to 11) p < 0.001] and 1-year survival higher [73.4% (95%CI 67.7 to 78.3 vs 83.8% (95%CI 78.8 to 87.7) p<0.003]. CONCLUSIONS: The use of GDHT decreases intraoperative complications and postoperative cardiovascular, respiratory and infectious but not postoperative renal complications. This strategy was associated with a shorter hospital stay and increased 1-year survival. TRIAL REGISTRATION: ClinicalTrials.gov NCT02479321 .

Hypotension Prediction Index Software to Prevent Intraoperative Hypotension during Major Non-Cardiac Surgery: Protocol for a European Multicenter Prospective Observational Registry (EU-HYPROTECT).

Background: Intraoperative hypotension is common in patients having non-cardiac surgery and associated with postoperative acute myocardial injury, acute kidney injury, and mortality. Avoiding intraoperative hypotension is a complex task for anesthesiologists. Using artificial intelligence to predict hypotension from clinical and hemodynamic data is an innovative and intriguing approach. The AcumenTM Hypotension Prediction Index (HPI) software (Edwards Lifesciences; Irvine, CA, USA) was developed using artificial intelligence­specifically machine learning­and predicts hypotension from blood pressure waveform features. We aimed to describe the incidence, duration, severity, and causes of intraoperative hypotension when using HPI monitoring in patients having elective major non-cardiac surgery. Methods: We built up a European, multicenter, prospective, observational registry including at least 700 evaluable patients from five European countries. The registry includes consenting adults (≥18 years) who were scheduled for elective major non-cardiac surgery under general anesthesia that was expected to last at least 120 min and in whom arterial catheter placement and HPI monitoring was planned. The major objectives are to quantify and characterize intraoperative hypotension (defined as a mean arterial pressure [MAP] < 65 mmHg) when using HPI monitoring. This includes the time-weighted average (TWA) MAP < 65 mmHg, area under a MAP of 65 mmHg, the number of episodes of a MAP < 65 mmHg, the proportion of patients with at least one episode (1 min or more) of a MAP < 65 mmHg, and the absolute maximum decrease below a MAP of 65 mmHg. In addition, we will assess causes of intraoperative hypotension and investigate associations between intraoperative hypotension and postoperative outcomes. Discussion: There are only sparse data on the effect of using HPI monitoring on intraoperative hypotension in patients having elective major non-cardiac surgery. Therefore, we built up a European, multicenter, prospective, observational registry to describe the incidence, duration, severity, and causes of intraoperative hypotension when using HPI monitoring in patients having elective major non-cardiac surgery.