Perioperative Quality Initiative consensus statement on preoperative blood pressure, risk and outcomes for elective surgery

Perioperative Medication Management

Medication management in the perioperative period is a critical part of the decision-making prior to surgery. While randomized trial levels of evidence in this space are scant, retrospective data and expert consensus provide practical guidance for these decisions. Clinicians must understand risks and benefits of withholding versus continuing medications, stop medications based on pharmacokinetics and effect on primary disease and surgical risk, and resume medications after surgery in a timely manner. Knowing alternate routes of medication administration can help keep chronic disease processes stable through surgery.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

Impact of Preanesthetic Blood Pressure Deviations on 30-Day Postoperative Mortality in Non-Cardiac Surgery Patients

BACKGROUND

Blood pressure readings taken before anesthesia often influence the decision to delay or cancel elective surgeries. However, the implications of these specific blood pressure values, especially how they compare to baseline, on postoperative in-hospital 30-day mortality remain underexplored. This research aimed to examine the effect of discrepancies between the baseline blood pressure evaluated in the ward a day before surgery, and the blood pressure observed just before the administration of anesthesia, on the postoperative mortality risks.

METHODS

The study encompassed 60,534 adults scheduled for non-cardiac surgeries at a tertiary care center in Seoul, Korea. Baseline blood pressure was calculated as the mean of the blood pressure readings taken within 24 hours prior to surgery. The preanesthetic blood pressure was the blood pressure measured right before the administration of anesthesia. We focused on in-hospital 30-day mortality as the primary outcome.

RESULTS

Our research revealed that a lower preanesthetic systolic or mean blood pressure that deviates by 20 mmHg or more from baseline significantly increased the risk of 30-day mortality. This association was particularly pronounced in individuals with a history of hypertension and those aged 65 and above. Higher preanesthetic blood pressure was not significantly associated with an increased risk of 30-day mortality.

CONCLUSION

We found that a lower preanesthetic blood pressure compared to baseline significantly increased the 30-day postoperative mortality risk, whereas a higher preanesthetic blood pressure did not. Our study emphasizes the critical importance of accounting for variations in both baseline and preanesthetic blood pressure when assessing surgical risks and outcomes.

Personalised blood pressure management during major noncardiac surgery and postoperative neurocognitive disorders: a randomised trial

Background

It remains unknown whether there is a causal relationship between intraoperative hypotension and postoperative neurocognitive disorders. We tested the hypothesis that personalised-compared to routine-intraoperative blood pressure management reduces the incidence of postoperative neurocognitive disorders in patients having major noncardiac surgery.

Methods

In this single-centre trial, 328 elective major noncardiac surgery patients were randomly allocated to receive personalised blood pressure management (i.e. maintaining intraoperative mean arterial pressure [MAP] above preoperative baseline MAP from automated 24-h blood pressure monitoring) or routine blood pressure management (i.e. maintaining MAP above 65 mm Hg). The primary outcome was the incidence of neurocognitive disorders (composite of delayed neurocognitive recovery and delirium) between postoperative days 3 and 7.

Results

The primary outcome, neurocognitive disorders, occurred in 18 of 147 patients (12%) assigned to personalised and 21 of 148 patients (14%) assigned to routine blood pressure management (odds ratio [OR]=0.84, 95% confidence interval [CI]: 0.40-1.75, P=0.622). Delayed neurocognitive recovery occurred in 17 of 146 patients (12%) assigned to personalised and 17 of 145 patients (12%) assigned to routine blood pressure management (OR=0.99, 95% CI: 0.45-2.17, P=0.983). Delirium occurred in 2 of 157 patients (1%) assigned to personalised and 4 of 158 patients (3%) assigned to routine blood pressure management (OR=0.50, 95% CI: 0.04-3.53, P=0.684).

Conclusions

Personalised intraoperative blood pressure management maintaining preoperative baseline MAP neither reduced the incidence of the composite primary outcome neurocognitive disorders between postoperative days 3 and 7 nor the incidences of the components of the composite primary outcome-delayed neurocognitive recovery and delirium-compared to routine blood pressure management in patients having major noncardiac surgery.

Clinical trial registration

ClinicalTrials.gov (NCT03442907).

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.

Association between Preoperative Blood Pressures and Postoperative Adverse Events

BACKGROUND

The relationship between postoperative adverse events and blood pressures in the preoperative period remains poorly understood. This study tested the hypothesis that day-of-surgery preoperative blood pressures are associated with postoperative adverse events.

METHODS

The authors conducted a retrospective, observational study of adult patients having elective procedures requiring an inpatient stay between November 2017 and July 2021 at Vanderbilt University Medical Center to examine the independent associations between preoperative systolic and diastolic blood pressures (SBP, DBP) recorded immediately before anesthesia care and number of postoperative adverse events-myocardial injury, stroke, acute kidney injury, and mortality-while adjusting for potential confounders. The study used multivariable ordinal logistic regression to model the relationship.

RESULTS

The analysis included 57,389 cases. The overall incidence of myocardial injury, stroke, acute kidney injury, and mortality within 30 days of surgery was 3.4% (1,967 events), 0.4% (223), 10.2% (5,871), and 2.1% (1,223), respectively. The independent associations between both SBP and DBP measurements and number of postoperative adverse events were found to be U-shaped, with greater risk both above and less than SBP 143 mmHg and DBP 86 mmHg-the troughs of the curves. The associations were strongest at SBP 173 mmHg (adjusted odds ratio, 1.212 vs. 143 mmHg; 95% CI, 1.021 to 1.439; P = 0.028), SBP 93 mmHg (adjusted odds ratio, 1.339 vs. 143 mmHg; 95% CI, 1.211 to 1.479; P < 0.001), DBP 106 mmHg (adjusted odds ratio, 1.294 vs. 86 mmHg; 95% CI, 1.003 to 1.17671; P = 0.048), and DBP 46 mmHg (adjusted odds ratio, 1.399 vs. 86 mmHg; 95% CI, 1.244 to 1.558; P < 0.001).

CONCLUSIONS

Preoperative blood pressures both less than and above a specific threshold were independently associated with a higher number of postoperative adverse events, but the data do not support specific strategies for managing patients with low or high blood pressure on the day of surgery.

EDITOR’S PERSPECTIVE

The impact of intraoperative hypotension on postoperative acute kidney injury, mortality and length of stay following off-pump coronary artery bypass grafting surgery: a single-center retrospective cohort study

BACKGROUND

Off-pump coronary artery bypass grafting (OPCABG) presents distinct hemodynamic characteristics, yet the relationship between intraoperative hypotension and short-term adverse outcomes remains clear. Our study aims to investigate association between intraoperative hypotension and postoperative acute kidney injury (AKI), mortality and length of stay in OPCABG patients.

METHODS

Retrospective data of 494 patients underwent OPCABG from January 2016 to July 2023 were collected. We analyzed the relationship between intraoperative various hypotension absolute values (MAP > 75, 65 < MAP ≤ 75, 55 < MAP ≤ 65, MAP ≤ 55 mmHg) and postoperative AKI, mortality and length of stay. Logistic regression assessed the impacts of exposure variable on AKI and postoperative mortality. Linear regression was used to analyze risk factors on the length of intensive care unit stay (ICU) and hospital stay.

RESULTS

The incidence of AKI was 31.8%, with in-hospital and 30-day mortality at 2.8% and 3.5%, respectively. Maintaining a MAP greater than or equal 65 mmHg [odds ratio (OR) 0.408; p = 0.008] and 75 mmHg (OR 0.479; p = 0.024) was significantly associated with a decrease risk of AKI compared to MAP less than 55 mmHg for at least 10 min. Prolonged hospital stays were linked to low MAP, while in-hospital mortality and 30-day mortality were not linked to IOH but exhibited correlation with a history of myocardial infarction. AKI showed correlation with length of ICU stay.

CONCLUSIONS

MAP > 65 mmHg emerges as a significant independent protective factor for AKI in OPCABG and IOH is related to length of hospital stay. Proactive intervention targeting intraoperative hypotension may provide a potential opportunity to reduce postoperative renal injury and hospital stay.

TRIAL REGISTRATION

ChiCTR2400082518. Registered 31 March 2024. https://www.chictr.org.cn/bin/project/edit?pid=225349 .

Machine learning approach for predicting post-intubation hemodynamic instability (PIHI) index values: towards enhanced perioperative anesthesia quality and safety

BACKGROUND

Adequate preoperative evaluation of the post-intubation hemodynamic instability (PIHI) is crucial for accurate risk assessment and efficient anesthesia management. However, the incorporation of this evaluation within a predictive framework have been insufficiently addressed and executed. This study aims to developed a machine learning approach for preoperatively and precisely predicting the PIHI index values.

METHODS

In this retrospective study, the valid features were collected from 23,305 adult surgical patients at Peking Union Medical College Hospital between 2012 and 2020. Three hemodynamic response sequences including systolic pressure, diastolic pressure and heart rate, were utilized to design the post-intubation hemodynamic instability (PIHI) index by computing the integrated coefficient of variation (ICV) values. Different types of machine learning models were constructed to predict the ICV values, leveraging preoperative patient information and initiatory drug infusion. The models were trained and cross-validated based on balanced data using the SMOTETomek technique, and their performance was evaluated according to the mean absolute error (MAE), root mean square error (RMSE), mean absolute percentage error (MAPE) and R-squared index (R2).

RESULTS

The ICV values were proved to be consistent with the anesthetists' ratings with Spearman correlation coefficient of 0.877 (P < 0.001), affirming its capability to effectively capture the PIHI variations. The extra tree regression model outperformed the other models in predicting the ICV values with the smallest MAE (0.0512, 95% CI: 0.0511-0.0513), RMSE (0.0792, 95% CI: 0.0790-0.0794), and MAPE (0.2086, 95% CI: 0.2077-0.2095) and the largest R2 (0.9047, 95% CI: 0.9043-0.9052). It was found that the features of age and preoperative hemodynamic status were the most important features for accurately predicting the ICV values.

CONCLUSIONS

Our results demonstrate the potential of the machine learning approach in predicting PIHI index values, thereby preoperatively informing anesthetists the possible anesthetic risk and enabling the implementation of individualized and precise anesthesia interventions.

Perioperative Patients With Hemodynamic Instability: Consensus Recommendations of the Anesthesia Patient Safety Foundation

In November of 2022, the Anesthesia Patient Safety Foundation held a Consensus Conference on Hemodynamic Instability with invited experts. The objective was to review the science and use expert consensus to produce best practice recommendations to address the issue of perioperative hemodynamic instability. After expert presentations, a modified Delphi process using discussions, voting, and feedback resulted in 17 recommendations regarding advancing the perioperative care of the patient at risk of, or with, hemodynamic instability. There were 17 high-level recommendations. These recommendations related to the following 7 domains: Current Knowledge (5 statements); Preventing Hemodynamic Instability-Related Harm During All Phases of Care (4 statements); Data-Driven Quality Improvement (3 statements); Informing Patients (2 statements); The Importance of Technology (1 statement); Launch a National Campaign (1 statement); and Advancing the Science (1 statement). A summary of the recommendations is presented in Table 1 .

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.

Intraoperative arterial pressure management: knowns and unknowns

Preventing postoperative organ dysfunction is integral to the practice of anaesthesia. Although intraoperative hypotension is associated with postoperative end organ dysfunction, there remains ambiguity with regards to its definition, targets, thresholds for initiating treatment, and ideal treatment modalities.

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.

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.

Medical disease and ambulatory surgery, new insights in patient selection based on medical disease

PURPOSE OF REVIEW

Improvements in perioperative care contributed to enlarge the eligibility criteria for day case surgery and more and more patients with comorbidities may be concerned. However, underlying medical diseases may influence postoperative outcomes, and therefore, must be considered when selecting patients to undergo ambulatory surgery.

RECENT FINDINGS

To limit postoperative complications, rigid patient selection criteria are often applied in ambulatory surgery. In practice, however, most of these criteria predict the occurrence of treatable perioperative adverse events but not the need for unanticipated admission or readmission.

SUMMARY

The underlying medical diseases should not be considered as sole criteria but they should rather be regarded as a dynamic process, which includes the surgical procedure as well as the experience and expertise of the perioperative setting.

Cerebral hemodynamics during sustained intra-operative hypotension

Background Static cerebral autoregulation (CA) maintains cerebral blood flow (CBF) relatively constant above a mean arterial blood pressure (BP_mean) of 60-65 mmHg. Below this lower limit of CA (LLCA), CBF declines along with BP_mean. Data are lacking describing how CA reacts to sustained hypotension, since hypotension is usually avoided. In this study, we took advantage of a procedure requiring sustained hypotension. We assessed static CA for LLCA determination, and a more continuous CA, which counter short-term blood pressure variations. With these data, we analyzed CA during longstanding hypotension. Methods Continuous arterial blood pressure and middle cerebral artery blood flow velocity (MCAV_mean) were monitored in 23 patients that required deep intra-operative hypotension. The LLCA was determined for every patient, and BP_mean below this LLCA was classified as the patient specific hypotension. With the mean flow index (Mx_a) continuous CA (Mx_a-CA) was quantified. Mx_a was calculated and averaged after induction of general anesthesia (baseline), every 15 minutes during, and 15 minutes after one-hour of hypotension. Functioning CA was defined as Mx_a <0.4. Data are expressed as median (25^th-75^th percentile). Results The LLCA was located at 56 (47-74) mmHg. At baseline, Mx_a was 0.21 (0.14-0.32) and 0.61 (0.48-0.78) during hypotension (p<0.01), with no appreciable change over time, n=12. After blood pressure restoration, Mx_a improved, 0.25 (0.06-0.35, n=9). Conclusions Mx_a-CA became and remained disturbed during the one-hour of hypotension, and improved after blood pressure restoration. This completely reversible situation suggests no ischemic hyperemia occurs and renders an adaptation mechanism during sustained hypotension unlikely.

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.

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).

The blood pressure and use of tourniquet are related to local recurrence after intralesional curettage of primary benign bone tumors: a retrospective and hypothesis-generating study

Aims

Intralesional curettage is a commonly used treatment for primary bone tumors. However, local recurrence of tumors after curettage remains a major challenge.

Questions

(1) Is blood pressure related to local recurrence after intralesional curettage for benign or intermediate bone tumors? (2) What’s the impact of tourniquet usage on the risk of recurrence from high blood pressure?

Methods

This retrospective study evaluated patients receiving intralesional curettage for primary bone tumors from January 2011 to January 2015. A total of 411 patients with a minimum five-year follow-up were included for analysis. Demographic and disease-related variables were first assessed in univariable analyses for local recurrence risk. When a yielded p-value was < 0.2, variables were included in multivariable analyses to identify independent risk factors for local recurrence. Patients were then stratified by tourniquet usage (use/non-use), and risk from high blood pressure was evaluated in both subgroups.

Results

At an average follow-up of 6.8 ± 1.0 years, 63 of 411 patients (15.3%) experienced local recurrence. In multivariable analyses, local recurrence was associated with age (OR, 0.96; 95% CI, 0.94–0.99; p = 0.005); tumor type; lesion size (> 5 cm: OR, 3.58; 95% CI, 1.38–9.33; p = 0.009); anatomical site (proximal femur: OR, 2.49; 95% CI, 1.21–5.15; p = 0.014; proximal humerus: OR, 3.34; 95% CI, 1.61–6.92; p = 0.001); and preoperative mean arterial pressure (> 110 mmHg: OR, 2.61; 95% CI, 1.20–5.67; P = 0.015). In subgroup analyses, after adjusting for age, tumor type, lesion size, and anatomical site, tourniquet use modified the preoperative mean arterial pressure - recurrence relationship: when tourniquet was not used, preoperative mean arterial pressure predicted local recurrence (95–110 mmHg, 4.13, 1.42–12.03, p = 0.009; > 110 mmHg, 28.06, 5.27–149.30, p < 0.001); when tourniquet was used, preoperative mean arterial pressure was not related to local recurrence (all p values > 0.05).

Conclusions

A high preoperative blood pressure was related to local recurrence after intralesional curettage for primary bone tumors in our study. Tourniquet usage and controlling blood pressure might be beneficial for reducing local recurrence in patients scheduled to receive intralesional curettage for primary bone tumor treatment.

Level of evidence

Level IV, hypothesis-generating study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05157-4.

Patient Selection for Adult Ambulatory Surgery: A Narrative Review

With migration of medically complex patients undergoing more extensive surgical procedures to the ambulatory setting, selecting the appropriate patient is vital. Patient selection can impact patient safety, efficiency, and reportable outcomes at ambulatory surgery centers (ASCs). Identifying suitability for ambulatory surgery is a dynamic process that depends on a complex interplay between the surgical procedure, patient characteristics, and the expected anesthetic technique (eg, sedation/analgesia, local/regional anesthesia, or general anesthesia). In addition, the type of ambulatory setting (ie, short-stay facilities, hospital-based ambulatory center, freestanding ambulatory center, and office-based surgery) and social factors, such as availability of a responsible individual to take care of the patient at home, can also influence patient selection. The purpose of this review is to present current best evidence that would provide guidance to the ambulatory anesthesiologist in making an informed decision regarding patient selection for surgical procedures in freestanding ambulatory facilities.

Preoperative Care for Cataract Surgery: The Society for Ambulatory Anesthesia Position Statement

Cataract surgeries are among the most common procedures requiring anesthesia care. Cataracts are a common cause of blindness. Surgery remains the only effective treatment of cataracts. Patients are often elderly with comorbidities. Most cataracts can be treated using topical or regional anesthesia with minimum or no sedation. There is minimal risk of adverse outcomes. There is general consensus that cataract surgery is extremely low risk, and the benefits of sight restoration and preservation are enormous. We present the Society for Ambulatory Anesthesia (SAMBA) position statement for preoperative care for cataract surgery.

Obesity, metabolic syndrome, and inflammation: an update for anaesthetists caring for patients with obesity

Our understanding of chronic inflammation in obesity is evolving. Suggested mechanisms include hypoxia of adipose tissue and a subsequent increase in circulating cytokines. It is now known that adipose tissue, far from being an inert tissue, produces and secretes multiple peptides that influence inflammation and metabolism, including substrates of the renin-angiotensin-aldosterone system (RAAS). RAAS blocking antihypertensive medication and cholesterol-lowering agents are now being evaluated for their metabolic and inflammation-modulating effects. Surgery also has pro-inflammatory effects, which may be exacerbated in patients with obesity. This narrative review will summarise the recent literature surrounding obesity, metabolic syndrome, inflammation, and interplay with the RAAS, with evidence-based recommendations for the optimisation of patients with obesity, prior to surgery and anaesthesia.

Cardio- and Cerebrovascular Outcomes of Postoperative Acute Kidney Injury in Noncardiac Surgical Patients With Hypertension

Background: The cardiovascular and cerebrovascular risk of postoperative acute kidney injury (AKI) in surgical patients is poorly described, especially in the hypertensive population.

Methods: We conducted a retrospective cohort study among all hypertensive patients who underwent elective noncardiac surgery from January 1st, 2012 to August 1st, 2017 at the Third Xiangya Hospital. The primary outcomes were fatal stroke and fatal myocardial infarction (MI). The secondary outcomes were all-cause mortality.

Results: The postoperative cumulative mortality within 3 months, 6 months, 1 year, 2 years, and 5 years were 1.27, 1.48, 2.15, 2.15, and 5.36%, for fatal stroke, and 2.05, 2.27, 2.70, 3.37, and 5.61% for fatal MI, respectively, in patients with postoperative AKI. Compared with non-AKI patients, those with postoperative AKI had a significantly higher risk of fatal stroke and fatal MI within 3 months [hazard ratio (HR): 5.49 (95% CI: 1.88−16.00) and 11.82 (95% CI: 4.56−30.62), respectively], 6 months [HR: 3.58 (95% CI: 1.43−8.97) and 9.23 (95% CI: 3.89−21.90), respectively], 1 year [HR: 3.64 (95% CI: 1.63−8.10) and 5.14 (95% CI: 2.50−10.57), respectively], 2 years [HR: 2.21 (95% CI: 1.03−4.72) and 3.06 (95% CI: 1.66−5.64), respectively], and 5 years [HR: 2.27 (95% CI: 1.30−3.98) and 1.98 (95% CI: 1.16−3.20), respectively]. In subgroup analysis of perioperative blood pressure (BP) lowering administration, postoperative AKI was significantly associated with 1-year and 5-year risk of fatal stroke [HR: 9.46 (95% CI: 2.85−31.40) and 3.88 (95% CI: 1.67−9.01), respectively] in patients with ACEI/ARB, and MI [HR: 6.62 (95% CI: 2.23−19.62) and 2.44 (95% CI: 1.22−4.90), respectively] in patients with CCB.

Conclusion: Hypertensive patients with postoperative AKI have a significantly higher risk of fatal stroke and fatal MI, as well as all-cause mortality, within 5 years after elective noncardiac surgery. In patients with perioperative administration of ACEI/ARB and CCB, postoperative AKI was significantly associated with higher risk of fatal stroke and MI, respectively.

Perioperative Cardiac Risk Reduction in Noncardiac Surgery

Major adverse cardiovascular events are a significant source of morbidity and mortality in the perioperative setting, estimated to occur in approximately 5% of patients undergoing nonemergent noncardiac surgery. To minimize the incidence and impact of these events, careful attention must be paid to preoperative cardiovascular assessment to identify patients at high risk of cardiovascular complications. Once identified, cardiovascular risk reduction is achieved through optimization of medical conditions, appropriate management of medication, and careful monitoring to allow for early identification of-and intervention for-any new conditions that would increase the risk of adverse cardiovascular outcomes. The major cardiovascular and anesthesiology societies in the United States, Europe, and Canada have published guidelines for perioperative management of patients undergoing noncardiac surgery. However, since publication of these guidelines, there has been a practice-changing evolution in the medical literature. In this review, we attempt to reconcile the recommendations made in these 3 comprehensive guidelines, while updating recommendations, based on new evidence, when available.

Surrogate based continuous noninvasive blood pressure measurement

Arterial blood pressure is one of the most often measured vital parameters in clinical practice. State-of-the-art noninvasive ABP measurement technologies have noticeable limitations and are mainly based on uncomfortable techniques of complete or partial arterial occlusion by cuffs. Most commonplace devices provide only intermittent measurements, and continuous systems are bulky and difficult to apply correctly for nonprofessionals. Continuous cuffless ABP measurements are still an unmet clinical need and a topic of ongoing research, with only few commercially available devices. This paper discusses surrogate-based noninvasive blood pressure measurement techniques. It covers measurement methods of continuously and noninvasively inferring BP from surrogate signals without applying external pressures, except for reference or initialization purposes. The BP is estimated by processing signal features, so called surrogates, which are modulated by variations of BP. Discussed techniques include well-known approaches such as pulse transit time and pulse arrival time techniques, pulse wave analysis or combinations thereof. Despite a long research history, these methods have not found widespread use in clinical and ambulatory practice, in part due to technical limitations and the lack of a standardized regulatory framework. This work summarizes findings from an invited workshop of experts in the fields covering clinical expertise, engineering aspects, commercialization and standardization issues. The goal is to provide an application driven outlook, starting with clinical needs, and extending to technical actuality. It provides an outline of recommended research directions and includes a detailed overview of clinical use case scenarios for these technologies, opportunities, and limitations.

Implementation of evidence-based recommendations to reduce elective surgical case cancellations

BACKGROUND

Cancellation of elective surgical cases leads to a waste of resources, financial burden, patient dissatisfaction, extended hospital stay, and unnecessary repetition of preoperative preparations.

AIM

The objective of this study was to identify, analyze and manage the causes of cancellation of elective surgical cases in our institution.

METHODS

This quality improvement study compared preoperative cardiovascular event and case cancellation rates before and after implementing the practice of perioperative cardiovascular risk management. The study included the following phases: (1) Screening and identification of the most important reason for case cancellation; (2) Developing the strategy and internal protocol based on the international recommendations to minimize perioperative cardiovascular risk; (3) Implementing the internal protocol and monitoring preoperative cardiovascular events and case cancellation rate.

RESULTS

We achieved a reduction in surgical case cancellation rate: 83 (3.7%) out of 2242 in 2018 and 28 (1.1%) out of 2538 cases in 2019 were cancelled after the patient had been delivered to the operating room area.

CONCLUSION

Screening and identification of gaps in perioperative care as well as implementation of evidence-based recommendations can significantly improve the quality of patient care. In our case, implementing the internal protocol of cardiovascular risk management in perioperative period resulted in a reduction of preoperative hypertensive crisis, myocardial ischemia, heart rhythm disorder rates and in subsequently reduction in case cancellation rate.

Optimized non-uniform sampling of blood pressure time series from the operating room

OBJECTIVE

We investigate an optimized non-uniform sampling strategy for blood pressure time series from the operating room (OR). Our aim is to obtain an approximate bound on the achievable reconstruction fidelity given an average sampling rate constraint.

METHODS

Our data set consists of 117 hours of recordings of continuous invasive blood pressure from 28 surgery patients. We evaluate the root mean squared error (RMSE) of the zero-order hold sampling reconstruction of the blood pressure time series. We quantitatively compare the errors achieved by uniform versus optimized non-uniform sample placements for several average sample rates, ranging from 2 to 24 measurements per hour.

RESULTS

An optimized non-uniform measurement schedule can lead to approximately 50% reduction of reconstruction RMSE for systolic, mean, and diastolic blood pressure time series with respect to uniform sampling, while maintaining the same average sampling rate.

Anesthetic management of hypertensive patients

It is important for the clinicians to have a clear understanding of the anesthetic implications and increased risks due to hypertension to ensure safe surgical procedures in hypertensive patients. Preoperative hypertension is associated with greater intraoperative hemodynamic lability and an increased risk of perioperative cardiovascular complications. In addition to the patients’ baseline blood pressure (BP), the presence and severity of target organ damage and cardiovascular comorbidities should be evaluated preoperatively. Delaying surgery in hypertensive patients may be justified if there is an evidence of target organ damage that can be improved by such a delay. Further evaluation of suspected target organ damage before the surgery is also justified. Except withholding angiotensin-converting enzyme inhibitors/angiotensin receptor blockers 10 to 24 hours before the surgery, the continuation of preoperative antihypertensive therapy is generally recommended. Though maintaining perioperative BP within the range of 80%–90% to 110%–120% of the baseline BP (permissible BP decrease/increase ≤10%–20%) is generally recommended, an individualized and pathophysiology-based approach to control BP might be the best option throughout the perioperative period. In other words, BP targets in the perioperative period should be determined based on the type of surgery, patients’ baseline BP, risks of hypotension-related organ ischemia, and hypertension-related bleeding.

Association Between Use of Preoperative Antihypertensive Medication and 90-Day Mortality After Noncardiac Surgery: A Retrospective Cohort Study

BACKGROUND

This study aimed to determine whether use of preoperative antihypertensive medication is associated with postoperative 90-day mortality in the hypertensive adult population that underwent elective noncardiac surgery.

METHODS

In this retrospective cohort study, medical records of preoperative hypertensive patients who underwent noncardiac surgery at a single tertiary academic hospital from 2012 to 2018 were reviewed. Among the hypertensive patients, those prescribed to take antihypertensive medication continuously for more than 1 month before admission were defined as the HTN MED group; others were defined as the non-HTN MED group. Multiple imputation, propensity score (PS) matching, and logistic regression analysis were used for statistical analysis.

RESULTS

Overall, 35,589 preoperative hypertensive adult patients (HTN MED group: 26,154 patients, non-HTN MED group: 9,435 patients) were included in the analysis. After PS matching, each group comprised 6,205 patients; thus, 12,410 patients were included in the final analysis. The odds for 90-day mortality of the HTN MED group in the PS-matched cohort were 41% lower (odds ratio: 0.59, 95% confidence interval: 0.41-0.85; P = 0.005) than those of the non-HTN MED group. Comparable results were obtained in the multivariable logistic regression analysis of the entire cohort (odds ratio: 0.54, 95% confidence interval: 0.41-0.72; P < 0.001).

CONCLUSIONS

This study showed that the use of preoperative antihypertensive medication was associated with lower 90-day mortality among hypertensive patients who underwent noncardiac surgery. Therefore, preoperative screening and treatment with appropriate antihypertensive medication are important for hypertensive patients.

Upper limb dimensions in adults presenting for elective surgery - implications for blood pressure measurement

BACKGROUND

Arm conicity is associated with non-invasive blood pressure (NIBP) measurement error and may be avoided by using finger cuffs. Predicting arm conicity may help decisions regarding NIBP measurement techniques.

METHODS

We obtained upper limb measurements of adults presenting to the Pre-Anesthetic Clinic to determine: the suitability of arm and finger cuff sizes; the best anthropometric predictor of arm conicity based on the right arm slant angle; the incidence of a right arm slant angle < 83 degrees. Right mid-arm circumference (MAC) was compared to recommended cuff sizes and finger circumference compared to available cuffs. Slant angle was calculated from the measurements obtained. Linear regression was used to determine the better predictor of right arm slant angle. Correlation coefficients were calculated and R2 values compared.

RESULTS

Four hundred fifty-four patients participated and 453 had cone-shaped arms. One participant (0.2, 95% CI 0.0-1.2) had a MAC outside the recommended cuff range. Twenty-five participants (5.5, 95% CI 3.6-8.0) had a middle finger circumference greater than the largest ClearSight™ cuff. Body mass index (BMI), weight and right MAC all had low to moderate correlation with right arm slant angle (r = - 0.49, - 0.39, - 0.48, all p < 0.001) and regression revealed R2 values of 0.24, 0.15 and 0.23. Six participants (1.3, 95% CI 0.5-2.9) had a slant angle < 83 degrees.

CONCLUSION

Current NIBP equipment caters for most patients, based on the traditional measure of MAC. The utility of finger cuffs is limited by cuff size. BMI and right MAC showed the most promise in predicting arm conicity.

Arm Dimensions of Patients with Obesity and Their Experiences with Blood Pressure Measurement: An Observational Study

OBJECTIVE

In patients with obesity, it was determined what proportion had an arm slant angle (SA) < 83° and which measure best predicted arm conicity. Patient experience with noninvasive blood pressure measurement was evaluated.

METHODS

Arm SA was calculated from arm measurements. Linear regression determined whether BMI, weight, or right midarm circumference (MAC) best predicted conicity. Patient experiences were evaluated by survey and conventional content analysis of free-text comments.

RESULTS

One hundred participants had a median (interquartile range; range) BMI of 44.1 (39.1-53.1; 31.1-80.8). Thirty-three (33%) had a right arm SA < 83°. Seven (7%) had a right MAC outside the recommended range. BMI, weight, and the right MAC showed low correlation with and explained little of the variation (with age and sex adjustment) in right arm SA (r = -0.29, -0.27, -0.31; P = 0.003, 0.007, 0.002; R² = 0.09, 0.08, 0.10). Forty-two (42%) reported noninvasive blood pressure measurement caused severe pain, and 30 (30%) reported skin damage. Themes identified in free-text responses were "problems with equipment," "feelings and experiences," and "concerns about accuracy."

CONCLUSIONS

Current equipment is inadequate for patients with obesity based on MAC and conicity. Pain and skin damage contributed to negative experiences of these patients.

Perioperative blood pressure in the elderly

PURPOSE OF REVIEW

Hemodynamic instability is common in the perioperative period because of obligate physiologic changes that occur with surgery. Despite the frequency of such hemodynamic changes and the potential harm associated with them, particularly in the elderly, guidelines to optimize perioperative blood pressure are lacking. The present review examines recent evidence for perioperative blood pressure management in the elderly.

RECENT FINDINGS

Hypotension has been associated with poor outcomes, particularly renal injury, myocardial injury, and increased mortality, in the perioperative period. Hypertension, tachycardia, frequency of blood pressure monitoring, and management of chronic antihypertensive medications may also affect patient outcomes. Elderly patients may be especially prone to adverse events associated with perioperative hemodynamic instability.

SUMMARY

Precise and intentional management of hemodynamic parameters, medication regimens, and blood pressure monitoring may reduce adverse events in elderly patients undergoing surgery. Further investigation is required to identify the exact hemodynamic parameters that mitigate risk.

Perioperative Quality Initiative consensus statement on intraoperative blood pressure, risk and outcomes for elective surgery

BACKGROUND

Intraoperative mortality is now rare, but death within 30 days of surgery remains surprisingly common. Perioperative myocardial infarction is associated with a remarkably high mortality. There are strong associations between hypotension and myocardial injury, myocardial infarction, renal injury, and death. Perioperative arterial blood pressure management was thus the basis of a Perioperative Quality Initiative consensus-building conference held in London in July 2017.

METHODS

The meeting featured a modified Delphi process in which groups addressed various aspects of perioperative arterial pressure.

RESULTS

Three consensus statements on intraoperative blood pressure were established. 1) Intraoperative mean arterial pressures below 60-70 mm Hg are associated with myocardial injury, acute kidney injury, and death. Injury is a function of hypotension severity and duration. 2) For adult non-cardiac surgical patients, there is insufficient evidence to recommend a general upper limit of arterial pressure at which therapy should be initiated, although pressures above 160 mm Hg have been associated with myocardial injury and infarction. 3) During cardiac surgery, intraoperative systolic arterial pressure above 140 mm Hg is associated with increased 30 day mortality. Injury is a function of arterial pressure severity and duration.

CONCLUSIONS

There is increasing evidence that even brief durations of systolic arterial pressure <100 mm Hg and mean arterial pressure <60-70 mm Hg are harmful during non-cardiac surgery.