Angiotensin-converting enzyme inhibition and blood pressure response during total intravenous anaesthesia for minor surgery

Changes in blood catecholamines during induction of general anesthesia in patients with post-induction hypotension undergoing laparoscopic cholecystectomy: A single-center prospective cohort study

BACKGROUND

Post-induction hypotension (PIH) often occurs during general anesthesia induction. This study aimed to investigate blood catecholamine levels during induction of general anesthesia in patients with PIH undergoing laparoscopic cholecystectomy.

METHODS

This prospective study included 557 adult patients who underwent laparoscopic cholecystectomy under general anesthesia. PIH was defined as a greater than 20% decrease in systolic blood pressure from the pre-induction value, a systolic arterial pressure of less than 90 mmHg, or both. Plasma concentrations of epinephrine and norepinephrine during the induction of general anesthesia were determined using enzyme-linked immunosorbent assay. Multivariate logistic regression analysis evaluated the association between the clinical factors and PIH.

RESULTS

Of the 557 patients, 390 had PIH, and the remaining 167 were allocated to the non-PIH group. Changes in blood adrenaline, noradrenaline levels, or both were more pronounced in the PIH than in the non-PIH group (p<0.05). Age, body mass index, a history of hypertension, preoperative systolic blood pressure, and propofol or sufentanil dose were independent predictors of PIH.

CONCLUSION

The changes of blood catecholamines in patients with more stable hemodynamics during the induction of general anesthesia are smaller than that in patients with post-induction hypotension.

TRIAL REGISTRATION

ChiCTR2200055549, 12/01/2022.

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Systolic Blood Pressure Less Than 120 mmHg is a Safe and Effective Method to Minimize Bleeding After Facelift Surgery: A Review of 502 Consecutive Cases

BACKGROUND

Hematoma is the most common complication after facelift surgery. Hypertension is the major risk factor for hematoma following facelift. Measures taken to reduce systolic blood pressure perioperatively significantly reduce the risk of hematoma. There is evidence that treating systolic blood pressure of 140 mmHg or above reduces hematoma; there were no studies to date in which systolic blood pressures below 120 mmHg had been evaluated.

OBJECTIVES

To assess the safety and efficacy of maintaining systolic blood pressures of 120 mmHg or less postoperatively to reduce hematoma after facelift.

METHODS

A retrospective chart review of a single surgeon's series of facelift procedures from January 2004 to July 2018 was undertaken. Implementation of a more stringent perioperative blood pressure protocol (maintaining a systolic blood pressure of less than 120 mmHg postoperatively) was initiated in January of 2013, dividing patients into 2 groups.

RESULTS

A total of 502 consecutive patients who underwent a facelift by F.N. were included in the study. A total of 319 patients underwent a facelift before 2013, and a total of 183 patients underwent a facelift in 2013 or later. Overall, a total of 13 hematomas occurred during the entire 15-year study period (2.59%), of which 12 occurred before the implementation of a strict blood pressure regimen (3.76%), and only 1 occurred after the new protocol (0.5%). There were no adverse events related to the lower blood pressure.

CONCLUSIONS

Treating systolic blood pressure greater than 120 mmHg postoperatively is a safe and effective method for reducing the risk of hematoma after facelift.

Frequency of Intraoperative Hypotension After the Induction of Anesthesia in Hypertensive Patients with Preoperative Angiotensin-converting Enzyme Inhibitors

Introduction

The renin-angiotensin-aldosterone system (RAAS) is an important target in the treatment of hypertension. Angiotensin-converting enzyme (ACE) inhibitors block the conversion of angiotensin I to angiotensin II. ACE inhibitors not only treat hypertension but also decrease morbidity and mortality in heart failure patients and in patients with acute myocardial infarction. The discontinuation of ACE inhibitors before the surgery is still controversial. To assess the current magnitude of the problem in our population, we aimed to conduct this study, which evaluated the frequency of intraoperative hypotension after the induction of anesthesia in controlled hypertensive patients with preoperative ACE inhibitors.

Material and methods

This descriptive case series study was conducted at a tertiary hospital in a developing country after approval from the Ethics Review Committee. A total of 115 adult patients, from 16 to 60 years of age, who have undergone elective surgery, have controlled hypertension on the desired drugs for at least six months, have no history of any cardiac event, and have taken the drug on the morning of the surgery, were included in the study after written consent. The demographic data of the patients were entered into the proforma. Preoperative systolic, diastolic, and mean arterial pressure were recorded by the researcher or an assignee in the preoperative holding area. The patients were followed in the recovery room by the team conducting the study until 10 minutes after the arrival of the patient in the recovery room. All statistical analyses were performed using Statistical Packages for the Social Sciences version 19 (SPSS Inc., Chicago, IL). p-value ≤0.05 was considered significant.

Results

Of the 115 patients, 56 (48.7%) patients were in the age group between 51 and 60 years of age; 38 patients were between the ages of 41 and 50 years and only 21 patients were 40 years or less. On gender, 68 patients were female and 47 were male. According to body mass index (BMI), the majority of the patients were in the overweight group, amounting to 53 (46%), and 86 (74.78%) patients were known diabetics. Overall, 77 (66.96%) of the patients developed intraoperative hypotension with 41 (35.65%) patients requiring the use of vasopressors in order to correct the hypotension. No statistically significant difference was found between demographic and clinical variables.

Conclusion

Intraoperative hypotension is more frequent in patients with controlled hypertension on ACE inhibitors although more studies need to be conducted on a larger population in order to determine a more definitive result.

Perioperative management of angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers: a survey of perioperative medicine practitioners

Background

Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) are the most commonly prescribed antihypertensive medications in higher-risk surgical patients. However, there is no clinical consensus on their use in the perioperative period, in part, due to an inconsistent evidence-base. To help inform the design of a large multi-centre randomized controlled trial (ISRCTN17251494), we undertook a questionnaire-based survey exploring variability in ACEi/ARB prescribing in perioperative practice.

Methods

The online survey included perioperative scenarios to examine how consistent respondents were with their stated routine preoperative practice. Clinicians with an academic interest in perioperative medicine were primarily targeted between July and September 2017. STROBE guidelines for observational research and ANZCA Trials Group Survey Reporting recommendations were adhered to.

Results

194 responses were received, primarily from clinicians practicing in the UK. A similar minority of respondents continue ACEi (n = 57; 30%) and ARBs (n = 62; 32%) throughout the perioperative period. However, timing of preoperative cessation was highly variable, and rarely influenced by the pharmacokinetics of individual ACE-i/ARBs. Respondents’ stated routine practice was frequently misaligned with their management of common pre- and postoperative scenarios involving continuation or restarting ACE-i/ARBs.

Discussion

This survey highlights many inconsistencies amongst clinicians’ practice in perioperative ACE-i/ARB management. Studies designed to reveal an enhanced understanding of perioperative mechanisms at play, coupled with randomised controlled trials, are required to rationally inform the clinical management of ACE-i/ARBs in patients most at risk of postoperative morbidity.

Perioperative use of angiotensin-converting-enzyme inhibitors and angiotensin receptor antagonists

STUDY OBJECTIVE

Clinical repercussions of perioperative treatment with ACEIs/ARBs.

DESIGN

Systematic review according to PRISMA statement.

SETTING

Perioperative period.

PATIENTS

29 studies 11 cases/cases series, 12 observational studies and 6 randomized studies.

MEASUREMENTS

Arterial blood pressure differences, refractory hypotension, other comorbidities.

MAIN RESULTS

The studies show different results regarding the topics measured. They are divided in the results regarding blood pressure, long term morbidities and effects in neuraxial anesthesia.

CONCLUSIONS

Withholding AECI/ARBs on the morning prior to surgery could be recommended as a potentially effective measure, with a low level of evidence, in order to reduce the appearance of hypotension in the perioperative period of non-cardiac surgery.

Systemic hypertension and non-cardiac surgery

Primary systemic hypertension affects 10%–25% of individuals presenting for surgery and anaesthesia and constitutes an important cause of cancellation of elective surgeries. Much of the fear stems from the fact that hypertension may lead to adverse perioperative outcomes. Although long-standing hypertension increases the risk of stroke, renal dysfunction or major adverse cardiovascular events, the same is usually not seen in the perioperative period if blood pressure is <180/110 mmHg and this has been the overriding theme in the recent guidelines on perioperative blood pressure management. Newer concepts include isolated systolic hypertension and pulse pressure hypertension that are increasingly used to stratify risk. The aim of this review is to focus on the adult patient with chronic primary systemic hypertension posted for elective non-cardiac surgery and outline the perioperative concerns.

Perioperative Management of Patients Treated with Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers: A Quality Improvement Audit

Previous studies have shown that patients continuing angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers on the day of surgery are more likely to have significant intraoperative hypotension, higher rates of postoperative acute kidney injury and lower incidences of postoperative atrial fibrillation. However, many of these studies were prone to bias and confounding, and questions remain over the validity of these outcomes. This observational, before-and-after quality mprovement audit aimed to assess the effect of withholding these medications on the morning of surgery. We recruited 323 participants, with 83 (26%) having their preoperative angiotensin-converting enzyme inhibitor (ACEi) or angiotensin II receptor blocker (ARB) withheld on the day of surgery. There were only very small Spearman rank-order correlations between time since last dose of these medications (rho −0.12, P=0.057) and intraoperative and recovery room intravenous fluid administration (rho −0.11, P=0.042). There was no statistically significant difference between the continued or withheld groups in vasopressor (metaraminol use 3.5 [1.5–8.3] mg versus 3.5 [1.5–8.5] mg, P=0.67) or intravenous fluid administration (1000 ml [800–1500] ml versus 1000 [800–1500] ml, P=0.096), nor rates of postoperative acute kidney injury (13% vs 18%, P=0.25) or atrial fibrillation (15% versus 18%, P=0.71). This audit found no significant differences in measured outcomes between the continued or withheld ACEi/ARB groups. This finding should be interpreted with caution due to the possibility of confounding and an insufficient sample size. However, as the finding is in contrast to many previous studies, future prospective randomised clinical trials are required to answer this important question.

Optimal perioperative management of arterial blood pressure

Perioperative blood pressure management is a key factor of patient care for anesthetists, as perioperative hemodynamic instability is associated with cardiovascular complications. Hypertension is an independent predictive factor of cardiac adverse events in noncardiac surgery. Intraoperative hypotension is one of the most encountered factors associated with death related to anesthesia. In the preoperative setting, the majority of antihypertensive medications should be continued until surgery. Only renin-angiotensin system antagonists may be stopped. Hypertension, especially in the case of mild to moderate hypertension, is not a cause for delaying surgery. During the intraoperative period, anesthesia leads to hypotension. Hypotension episodes should be promptly treated by intravenous vasopressors, and according to their etiology. In the postoperative setting, hypertension predominates. Continuation of antihypertensive medications and postoperative care may be insufficient. In these cases, intravenous antihypertensive treatments are used to control blood pressure elevation.

Perioperative blood pressure variability in the treated hypertensive patients

Perioperative blood pressure (BP) management is important to prevent cardiovascular complication, especially for hypertensive patients. In the present study, we investigated perioperative BP variability and contributing factors in hypertensive patients. Subjects were 28 treated hypertensive patients who underwent total or subtotal gastrectomy. Ambulatory BP monitoring was carried out before and after (16 days in average) the surgery. Angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and diuretics were withdrawn on the previous day, while other drugs were administered until the day of surgery. BP, body weight, blood chemistry, as well as the use of intravenous vasopressor or vasodepressor agents during the perioperative period were investigated. The 24-hour BP before surgery was 124 ± 19/70 ± 12 mm Hg, and the number of antihypertensive drugs was 1.8. In 22 patients, intravenous vasopressor agents were used during surgery, while another patient received intravenous vasodepressor agents after surgery. The 24-hour BP significantly decreased after surgery (-8.2 ± 14.7/-2.6 ± 7.3 mm Hg). Body weight, serum Na, and hematocrit also decreased. There were nine patients whose 24-hour systolic BP decreased by more than 10 mm Hg and for two patients more than 20 mm Hg. The decrease in BP correlated with the change in serum Na. Forty-three percent of the patients who took ACE inhibitors/ARBs showed BP reduction greater than 10 mm Hg, while 25% of the patients without these drugs showed such BP reduction. Our findings suggest that 24-hour BP decreases after gastrectomy. Patients taking ACE inhibitors or ARBs may need careful monitoring to prevent excessive BP fall.