Intraoperative hypotension in ambulatory surgery centers

STUDY OBJECTIVES

To measure the incidence of intraoperative hypotension (IOH) during surgery in ambulatory surgery centers (ASCs) and describe associated characteristics of patients and procedures.

DESIGN

Retrospective analysis.

SETTING

20 ASCs.

PATIENTS

16,750 patients having non-emergent, non-cardiac surgery; ASA physical status 2 through 4.

INTERVENTIONS

None.

MEASUREMENTS

We assessed incidence of IOH using the definition from the Centers for Medicare & Medicaid Services (CMS) Merit-based Incentive Payment System (MIPS)-mean arterial pressure (MAP) < 65 mmHg for at least 15 cumulative minutes-and three secondary definitions: minutes of MAP <65 mmHg, area under MAP of 65 mmHg, and time-weighted average MAP <65 mmHg.

MAIN RESULTS

30.9% of ASC cases had a MAP <65 mmHg for at least 15 min. The incidence of IOH varied significantly, and was higher among younger adults (age 18-39; 36.2%), females (35.2%), and patients with ASA physical status 2 (32.8%). IOH increased with increasing surgery length, even when time-weighted, and was higher among low complexity (30.6%) than moderate complexity (28.8%) procedures, and highest among high complexity procedures (44.1%).

CONCLUSIONS

There was substantial occurrence of IOH in ASCs, similar to that described in academic hospital settings in previous literature. We hypothesize that this may reflect clinician preference not to intervene in perceived healthy patients or assumptions about ability to tolerate lower blood pressures on behalf of these patients. Future research will determine whether IOH in ACSs is associated with adverse outcomes to the same extent as described in more complex hospital-based surgeries.

Incidence of intraoperative hypotension during non-cardiac surgery in community anesthesia practice: a retrospective observational analysis

BACKGROUND

Intraoperative hypotension (IOH) is well-described in the academic setting but not in community practice. IOH is associated with risk of postoperative morbidity and mortality. This is the first report of IOH in the community setting using the IOH measure definition from the Centers for Medicare and Medicaid Services Merit-based Incentive Payment System program.

OBJECTIVES

To describe the incidence of IOH in the community setting; assess variation in IOH by patient-, procedure-, and facility-level characteristics; and describe variation in risk-adjusted IOH across clinicians.

METHODS

Design Cross-sectional descriptive analysis of retrospective data from anesthesia records in 2020 and 2021. Setting Forty-five facilities affiliated with two large anesthesia providers in the USA. Participants Patients aged 18 years or older having non-emergent, non-cardiac surgery under general, neuraxial, or regional anesthesia. Cases were excluded based on criteria for the IOH measure: baseline mean arterial pressure (MAP) below 65 mmHg prior to anesthesia induction; American Society of Anesthesiologists (ASA) physical status classification of I, V, or VI; monitored anesthesia care only; deliberate induced hypotension; obstetric non-operative procedures; liver or lung transplant; cataract surgery; non-invasive gastrointestinal cases. Main outcomes IOH, using four definitions. Primary definition: binary assessment of whether the case had MAP < 65 mmHg for 15 min or more. Secondary definitions: total number of minutes of MAP < 65 mmHg, total area under MAP of 65 mmHg, time-weighted average MAP < 65 mmHg.

RESULTS

Among 127,095 non-emergent, non-cardiac cases in community anesthesia settings, 29% had MAP < 65 mmHg for at least 15 min cumulatively, with an overall mean of 12.4 min < 65 mmHg. IOH was slightly more common in patients who were younger, female, and ASA II (versus III or IV); in procedures that were longer and had higher anesthesia base units; and in ambulatory surgery centers. Incidence of IOH varied widely across individual clinicians in both unadjusted and risk-adjusted analyses.

CONCLUSION

Intraoperative hypotension is common in community anesthesia practice, including among patients and settings typically considered "low risk." Variation in incidence across clinicians remains after risk-adjustment, suggesting that IOH is a modifiable risk worth pursuing in quality improvement initiatives.

Intraoperative hypotension during surgical treatment for Marfan syndrome scoliosis in children

PURPOSE

To explore the occurrence and risk factors of intraoperative hypotension during children's Marfan syndrome scoliosis surgery and summarize the associated hemodynamic features and handle measures.

METHODS

Twenty-two Marfan syndrome scoliosis patients who underwent spinal surgery at Beijing Children's Hospital were retrospectively reviewed between January 2001 and January 2020. Intraoperative hypotension is defined as the minimum mean arterial pressure ≤ 60 mm Hg. The patients were divided into the hypotension group and the control group. Clinical, radiographic, and operative data were compared between the two groups. The risk factors, hemodynamic features, and handle measures for intraoperative hypotension in Marfan syndrome scoliosis surgery were analyzed and summarized.

RESULTS

Twenty-two patients were included in the study, with a mean age of 11.4 years at initial surgery. The follow-up period ranged from 24 to 152 months. Intraoperative hypotension occurred in 14 cases, with an incidence of 63.6%. The proportion of pulmonary dysfunction in the hypotension group was higher than in the control group (100.0% vs 50.0%, p < 0.05). The spinal flexibility was significantly lower in the hypotension group (28.3% ± 14.2% vs 46.5% ± 11.5%, p < 0.05). Fourteen patients with intraoperative hypotension had decreased intraoperative systolic blood pressure 21.0%-50.0% compared with baseline. One patient had a transient decrease in the muscle strength of the lower limbs. No complications were observed during the follow-up.

CONCLUSION

The incidence of intraoperative hypotension in Marfan syndrome scoliosis children who underwent surgery was 63.6%. The risk factors included preoperative pulmonary dysfunction and poor spinal flexibility. Comprehensive preoperative evaluation and effective hemodynamic handling measures should be undertaken to prevent further complications in children with Marfan syndrome scoliosis.

Effects of short-term bisoprolol on perioperative myocardial injury in patients undergoing non-cardiac surgery: a randomized control study

The protective role of preoperative beta-blocker in patients undergoing non-cardiac surgery is unknown. We aimed to evaluate the effects of beta-blocker on perioperative myocardial injury in patients undergoing non-cardiac surgery. We consecutively enrolled 112 patients undergoing non-cardiac surgery. They were randomly allocated to receive bisoprolol or placebo given at least 2 days preoperatively and continued until 30 days after surgery. The primary outcome was incidence of perioperative myocardial injury defined by a rise of high-sensitive troponin-T (hs-TnT) more than 99th percentile of upper reference limit or a rise of hs-TnT more than 20% if baseline level is abnormal. Baseline characteristics were comparable between bisoprolol and placebo in randomized cohort Mean age was 62.5 ± 11.8 years and 76 (67.8%) of 112 patients were male. Among 112 patients, 49 (43.8%) underwent vascular surgery and 63 (56.2%) underwent thoracic surgery. The median duration of assigned treatment prior to surgery was 4 days (2-6 days). We did not demonstrate the significant difference in the incidence of perioperative myocardial injury [52.6% (30 of 57 patients) vs. 49.1% (27 of 55 patients), P = 0.706]. In addition, the incidence of intraoperative hypotension was higher in bisoprolol group than placebo group in patients undergoing non-cardiac surgery [70.2% (40 of 57 patients) vs. 47.3% (26 of 55 patients), P = 0.017]. We demonstrated that there was no statistically significant difference in perioperative myocardial injury observed between patients receiving bisoprolol and placebo who had undergone non-cardiac surgery.

Early intraoperative hypotension and its associated factors among surgical patients undergoing surgery under general anesthesia: An observational study

Background

Early intraoperative hypotension (eIOH) is a common complication of general anesthesia and is significantly associated with postoperative morbidity and mortality. The incidence of eIOH was high, especially in resource-limited settings. Identifying the factors associated with the occurrence of eIOH might allow avoidance and planning of a timely treatment of it.

Objective

To assess the incidence of early intraoperative hypotension and its associated factors among surgical patients undergoing Surgical procedures under general anesthesia at XX Comprehensive Specialized Hospital, North-central Ethiopia, 2021.

Methods

A total of 424 surgical patients under general anesthesia were included in this prospective observational study. The data were collected by a structured questionnaire. Variables with p-values of less than 0.2 in the bivariable logistic regression were fitted to multivariable logistic regression. Data was presented in odds ratios with a 95% confidence interval. Descriptive statistics were used to summarize data.

Results

The incidence of early intra-operative hypotension (eIOH) was 21.2%. In this study older age (age≥ 60 years) (AOR: 2.063 (95% CI;1.194, 3.563)), ASA physical status (AOR: (II2.259 (95% CI;1.229, 4.153)), III(AOR: 2.810 (95% CI;1.319, 5.986)), a BMI of 25–29.9 kg/m2 (AOR: 2.098 (1.128, 3.901), a BMI of ≥30 kg/m2 (AOR: 3.090 (95% CI;1.324, 7.210)), emergency surgical procedures (AOR: 2.215 (95% CI;1.287, 3.810)), the estimated blood loss greater than 500 ml (AOR: 2.510 (95% CI;1.478, 4.261)) were found to be independent factors of eIOH.

Conclusion

This study revealed that the incidence of eIOH was high (21.2%). Older age, ASA II and III, BMI ≥25, emergency surgical procedures, and a significant amount of blood loss (EBL ≥500 ml) were the main predictors of an increased occurrence of eIOH.

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Early intraoperative hypotension is associated with postoperative morbidity and mortality.

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Emergency surgical procedures, and a significant amount of blood loss are the main predictors of an increased occurrence of eIOH.

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Thyroidectomy has a relatively short duration and less amount of estimated blood loss when compared to major surgical procedures.

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The occurrence of eIOH after general anesthesia for general surgery is a common problem.

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Arterial hypotension in patients undergoing surgery under general anesthesia usually described by the very general term intraoperative hypotension.

Blood pressure measurements during intraoperative pediatric scoliosis surgery

Background:

Intraoperative hypotension is frequently encountered during surgery and it can be associated with adverse outcomes. Blood pressure monitoring is critical during surgery, but there are no universally agreed upon standards for interpreting values of hypotension and no consensus regarding interventions.

Material and Methods:

We performed a retrospective chart review of pediatric patients who underwent idiopathic scoliosis surgery by a single surgeon. We used the arterial line for all measures. Intraoperative hypotension was defined as 20% decrease of the baseline systolic blood pressure (SBP), 30% decrease of baseline SBP, or mean arterial pressure less than 60 mmHg. Use of vasopressor agents was also recorded and correlated with blood pressure definitions.

Results:

Seventy idiopathic scoliosis patients were retrospectively evaluated. There was a significant correlation between the three measures of hypotension. Sixty percent of the patients received vasopressors. There was a significant correlation between a drop of mean arterial pressure to less than 60 mmHg and the use of the ephedrine. We did not find any changes on neuromonitoring measures during the case and there were no intraoperative or one-month postoperative complications.

Conclusions:

Blood pressure is only one of the measures anesthesiologists look to for good perfusion during surgery. Pediatric anesthesiologists and orthopedics agree in trying tight blood pressure control during surgery to decrease blood loss, but what the exact definition of that blood pressure number is, is still unclear. We propose that using mean arterial pressure less than 60 mmHg is perhaps a better definition. We provide recommendations for future studies.

Efficacy of low dose bupivacaine with intrathecal fentanyl for cesarean section on maternal hemodynamic: Systemic review and meta-analysis

Hypotension during spinal Anesthesia is the most common complication with maternal and neonatal morbidity and mortality. Low dose bupivacaine with intrathecal fentanyl is recommended as strategy to prevent spinal Anesthesia induced hypotension and related complications. The aim of this systemic review is to evaluate the efficacy of low dose bupivacaine with Intrathecal fentanyl on the improvement of maternal and neonatal outcomes compared to conventional dose bupivacaine among mothers who undergone cesarean section. We conducted a systemic search of the electronic databases of Pubmed, Medline, LILACS and others with PICO strategy for randomized controlled clinical trials comparing low dose bupivacaine with fentanyl and conventional dose bupivacaine for cesarean section. Joanna Briggs Institute (JBI) standardized data extraction form was used for data extraction and finally entered into Review Manager for data synthesis. Ten Randomized trials (552) were included in this review. Incidence of hypotension was less likely in mothers who received low dose bupivacaine with Fentanyl as compared to those with conventional dose of bupivacaine alone (RR = 0.43, 95% confidence interval (CI) 0.12-0.47, ten trials, 552 participants). The review revealed that Low dose bupivacaine combined with intrathecal Fentanyl decrease incidence of hypotension.

The prevalence of cardiovascular autonomic neuropathy and its influence on post induction hemodynamic variables in patients with and without diabetes; A prospective cohort study

Background

Cardiovascular autonomic neuropathy (CAN) is a known complication of diabetes, but is also diagnosed in patients without diabetes. CAN may be related to perioperative hemodynamic instability. Our objective was to investigate if patients with diabetes would have a higher prevalence of CAN compared to patients without diabetes undergoing surgery. We further studied its relation to changes in post-induction hemodynamic variables.

Methods

We prospectively included 82 adult patients, 55 with DM, 27 without DM, scheduled for major abdominal or cardiac surgery. Patients performed four autonomic function tests on the day before surgery. Primary outcomes were the prevalence of CAN and the relation between CAN and severe post-induction hypotension, defined as mean arterial pressure (MAP) < 50 mmHg or ≥ 50% decrease from baseline. Secondary outcomes were the relation between CAN, intraoperative hypotension, MAP < 65 mmHg for more than 13 minutes, and the use of vasopressor therapy.

Results

The prevalence of CAN in patients with or without DM was 71% versus 63%, (p = 0.437). CAN was not associated with severe post induction hypotension (CAN+ vs. CAN–: 21% vs. 19.2%, p = 0.819) nor with intraoperative hypotension (16% vs. 15%, p = 0.937). Patients with definite CAN received more norepinephrine in the perioperative period compared to patients with mild CAN or no CAN (0.07 mcg kg^-1 min^-1 (0.05–0.08) vs. 0.03 (0.01–0.07) vs. 0.02 (0.01–0.06) respectively, p = 0.001).

Conclusions

The majority of patients studied had mild to moderate CAN, regardless of the presence of DM. Assessing CAN before surgery did not identify patients at risk for post induction and intraoperative hypotension in our cohort.

Trial registration

Dutch Trial Registry (www.trialregister.nl) NTR4976.