Association of Neuraxial Anesthesia With Postoperative Venous Thromboembolism After Noncardiac Surgery: A Propensity-Matched Analysis of ACS-NSQIP Database

Construction and verification of a machine learning-based prediction model of deep vein thrombosis formation after spinal surgery

BACKGROUND

Deep vein thromboembolism (DVT) is a common postoperative complication with high morbidity and mortality rates. However, the safety and effectiveness of using prophylactic anticoagulants for preventing DVT after spinal surgery remain controversial. Hence, it is crucial to predict whether DVT occurs in advance following spinal surgery. The present study aimed to establish a machine learning (ML)-based prediction model of DVT formation following spinal surgery.

METHODS

We reviewed the medical records of patients who underwent elective spinal surgery at the Third Affiliated Hospital of Zunyi Medical University (TAHZMU) from January 2020 to December 2022. We ultimately selected the clinical data of 500 patients who met the criteria for elective spinal surgery. The Boruta-SHAP algorithm was used for feature selection, and the SMOTE algorithm was used for data balance. The related risk factors for DVT after spinal surgery were screened and analyzed. Five ML algorithm models were established. The data of 150 patients treated at the Affiliated Hospital of Zunyi Medical University (AHZMU) from July 2023 to October 2023 were used for external verification of the model. The area under the curve (AUC), geometric mean (G-mean), sensitivity, accuracy, specificity, and F1 score were used to evaluate the performance of the models.

RESULTS

The results revealed that activated partial thromboplastin time (APTT), age, body mass index (BMI), preoperative serum creatinine (Crea), anesthesia time, rocuronium dose, and propofol dose were the seven important characteristic variables for predicting DVT after spinal surgery. Among the five ML models established in this study, the random forest classifier (RF) showed superior performance to the other models in the internal validation set.

CONCLUSION

Seven preoperative and intraoperative variables were included in our study to develop an ML-based predictive model for DVT formation following spinal surgery, and this model can be used to assist in clinical evaluation and decision-making.

Neuraxial versus general anesthesia for perioperative outcomes and resource utilization following knee arthroplasty: experience from a large national database

INTRODUCTION

Attentions have been paid to the optimal anesthesia for knee arthroplasty (KA). We sought to investigate whether neuraxial anesthesia (NA) is superior to general anesthesia (GA) in terms of perioperative outcomes and resource utilization following KA.

METHODS

Patients undergoing primary KA registered in the Hospital Quality Monitoring System (HQMS) in China during 2013-2019 were identified. By utilizing a time-stratified propensity score matching, every patient receiving NA was matched by propensity score to a patient receiving GA. Then, we conducted Poisson, logistic, and linear regression to compare NA with GA in terms of perioperative outcomes and resource utilization.

RESULTS

Of 109,132 included participants, 75,945 (69.59%) underwent KA with GA and 33,187 (30.41%) with NA. After propensity score matching (26,425 participants per group), NA was associated with lower incidence of blood transfusion (OR: 0.82, 95% CI 0.77-0.87; p < 0.0001), 30-day readmission (OR: 0.76, 95% CI 0.68-0.84; p < 0.0001), and 90-day readmission (OR: 0.83, 95% CI 0.77-0.90; p < 0.0001). No statistically significant difference in in-hospital mortality, incidence of pulmonary embolism, deep vein thrombosis, and surgical site infection was found. In addition, NA was associated with a 1% decrease in length of stay (95% CI 0-2%; p = 0.0070) and a 3% lower total hospital charge (95% CI 2-4%; p < 0.0001) when compared with GA.

CONCLUSION

Compared with GA, NA was associated with decreased incidence of blood transfusion, readmission, reduced length of stay, and total hospital charge following KA, suggesting the favorable role of NA for perioperative outcomes and resource utilization in KA.

Defining the role of thoracic spinal anaesthesia in the 21st century: a narrative review

Since the performance of the first thoracic spinal anaesthetic in early 1908 many anaesthetists have gained interest in this unorthodox neuraxial anaesthetic technique. The main rationale justifying its use is to prevent complications related to general anaesthesia in high-risk patient populations. There is, however, significant debate regarding this practice around the world. The main concerns are fear of iatrogenic injury to the spinal cord, cephalad spread of local anaesthetic causing a complete spinal block, and haemodynamic instability owing to blockade of cardioaccelerator sympathetic fibres. The purpose of this narrative review is to appraise the literature critically regarding thoracic spinal anaesthesia, to synthesise the available information, and to provide a summary of evidence justifying its use in modern anaesthesia.

New insight into the analgesic recipe: A cohort study based on smart patient-controlled analgesia pumps records

Purpose: Intravenous patient-controlled analgesia (IV-PCA) has been widely used; however, regimen criteria have not yet been established. In China, the most often used opioid is sufentanil, for which repeated doses are a concern, and empirical flurbiprofen axetil (FBP) as an adjuvant. We hypothesized that hydromorphone would be a better choice and also evaluated the effectiveness of FBP as an adjuvant.

Methods: This historical cohort study was conducted in two tertiary hospitals in China and included 12,674 patients using hydromorphone or sufentanil for IV-PCA between April 1, 2017, and January 30, 2021. The primary outcome was analgesic insufficiency at static (AIS). The secondary outcomes included analgesic insufficiency with movement (AIM) and common opioid-related adverse effects such as postoperative nausea and vomiting (PONV) and dizziness.

Results: Sufentanil, but not the sufentanil-FBP combination, was associated with higher risks of AIS and AIM compared to those for hydromorphone (OR 1.64 [1.23, 2.19], p < 0.001 and OR 1.42 [1.16, 1.73], p < 0.001). Hydromorphone combined with FBP also decreased the risk of both AIS and AIM compared to those for pure hydromorphone (OR 0.74 [0.61, 0.90], p = 0.003 and OR 0.80 [0.71, 0.91], p < 0.001). However, the risk of PONV was higher in patients aged ≤35 years using FBP (hydromorphone-FBP vs. hydromorphone and sufentanil-FBP vs. hydromorphone, OR 1.69 [1.22, 2.33], p = 0.001 and 1.79 [1.12, 2.86], p = 0.015).

Conclusion: Hydromorphone was superior to sufentanil for IV-PCA in postoperative analgesia. Adding FBP may improve the analgesic effects of both hydromorphone and sufentanil but was associated with an increased risk of PONV in patients <35 years of age.

A Systematic Review and Meta-analysis of General versus Regional Anesthesia for Lower Extremity Amputation

OBJECTIVE

Postoperative morbidity in patients undergoing lower extremity amputation (LEA) has remained high. Studies investigating the influence of the anesthetic modality on the postoperative outcomes have yielded conflicting results. The aim of our study was to assess the effects of regional anesthesia vs general anesthesia on postoperative complications for patients undergoing LEA.

METHODS

We systematically searched PubMed, Embase, MEDLINE, Web of Science, and Google Scholar from 1990 to 2022 for studies investigating the effect of the anesthetic modality on the postoperative outcomes after LEA. Regional anesthesia (RA) included neuraxial anesthesia and peripheral nerve blocks. The outcomes included 30-day mortality, respiratory failure (unplanned postoperative intubation, failure to wean, mechanical ventilation >24 hours), surgical site infection, cardiac complications, urinary tract infection, renal failure, sepsis, venous thrombosis, pneumonia, and myocardial infarction.

RESULTS

Of the 25 studies identified, we included 10 retrospective observational studies with 81,736 patients, of whom 69,754 (85.3%) had received general anesthesia (GA) and 11,980 (14.7%) had received RA. In the GA group, 50,468 patients were men (63.8%), and in the RA group, 7813 patients were men (62.3%). The results of the meta-analyses revealed that GA was associated with a higher rate of respiratory failure (odds ratio, 1.38; 95% confidence interval, 1.06-1.80; P = .02) and sepsis (odds ratio, 1.21; 95% confidence interval, 1.11-1.33; P < .0001) compared with RA. No differences were found in postoperative 30-day mortality, surgical site infection, cardiac complications, urinary tract infection, renal failure, venous thrombosis, pneumonia, and myocardial infarction between the GA and RA groups.

CONCLUSIONS

The results of our meta-analysis have shown that GA could be associated with a higher rate of respiratory failure and sepsis compared with RA for LEA.

Opioid-Free Segmental Thoracic Spinal Anesthesia with Intrathecal Sedation for Breast and Axillary Surgery: Report of Four Cases

Purpose

Few studies have described segmental thoracic spinal anesthesia (STSA) as primary anesthesiologic method in breast and axillary surgery, documenting the association of intrathecal local anesthetics and opioids. This case series reports an opioid-free scheme of STSA in four elderly patients undergoing major breast and axillary oncological surgery.

Patients and Methods

STSA was performed in three female patients undergoing unilateral mastectomy ± axillary lymph node dissection (ALND) or sentinel lymph node biopsy for invasive ductal carcinoma and in one male patient undergoing ALND for melanoma metastases. The level of needle insertion was included between T6-8, via a median or paramedian approach. Midazolam (2 mg) and ketamine (20 mg) were used as adjuvants for intrathecal sedation, followed by the administration of hypobaric ropivacaine 0.25% at a dose of 8 mg. The level of sensory blockade achieved was comprised between C2-3 and T11-12. Postoperative analgesia was maintained through continuous intravenous administration of Ketorolac by an elastomeric pump (90 mg over 24 hrs.).

Results

Spinal anesthesia was completed without complications in all patients. Conversion to general anesthesia (GA) and perioperative intravenous sedation were not required. No major postoperative complications and no episodes of postoperative nausea and vomiting (PONV) were reported. No rescue analgesic was administered. All patients were discharged in postoperative day 2 and are alive at 30, 29, 27 and 13 months after surgery, respectively. High grade of satisfaction on the anesthesiologic method was expressed by all cases.

Conclusion

STSA with local anesthetic plus midazolam and ketamine might be considered a safe and effective alternative to GA, even in surgeries involving the breast and axillary region, particularly in elderly and frail patients. Larger prospective studies are required to validate these findings.

Big Data in Studying Acute Pain and Regional Anesthesia

The digital transformation of healthcare is advancing, leading to an increasing availability of clinical data for research. Perioperative big data initiatives were established to monitor treatment quality and benchmark outcomes. However, big data analyses have long exceeded the status of pure quality surveillance instruments. Large retrospective studies nowadays often represent the first approach to new questions in clinical research and pave the way for more expensive and resource intensive prospective trials. As a consequence, the utilization of big data in acute pain and regional anesthesia research has considerably increased over the last decade. Multicentric clinical registries and administrative databases (e.g., healthcare claims databases) have collected millions of cases until today, on which basis several important research questions were approached. In acute pain research, big data was used to assess postoperative pain outcomes, opioid utilization, and the efficiency of multimodal pain management strategies. In regional anesthesia, adverse events and potential benefits of regional anesthesia on postoperative morbidity and mortality were evaluated. This article provides a narrative review on the growing importance of big data for research in acute postoperative pain and regional anesthesia.

Continuous thoracic spinal anesthesia with local anesthetic plus midazolam and ketamine is superior to local anesthetic plus fentanyl in major abdominal surgery

BACKGROUND

Limited studies have applied thoracic continuous spinal anesthesia in abdominal surgery, relying exclusively on opioids. This retrospective study analyzes 2 different schemes of thoracic continuous spinal anesthesia and postoperative analgesia in elderly patients undergoing major abdominal surgery.

METHODS

A total of 98 patients aged ≥ 75 years were divided into 2 groups. The control group (60 patients) received bupivacaine plus fentanyl, whereas the study group (38 patients) received bupivacaine plus ketamine and midazolam. Both received analogous postoperative continuous intrathecal analgesia. Several perioperative variables were evaluated.

RESULTS

Spinal anesthesia was performed without complications in all patients. Doses of noradrenaline administered, incidence of respiratory depression, need for intraoperative sedation, and time to first flatus were significantly reduced in the bupivacaine plus ketamine and midazolam group.

CONCLUSION

In a population of frail, elderly patients, thoracic continuous spinal anesthesia with local anesthetic plus midazolam and ketamine was superior to local anesthetic plus fentanyl. In the group receiving local anesthetic plus midazolam and ketamine, the incidence of respiratory depression was reduced, and doses of norepinephrine and intraoperative sedating medications were lower. Intraoperative anesthesia and postoperative analgesia were similar in both groups.

Clinical outcomes and anesthetic management of pregnancies with placenta previa and suspicion for placenta accreta undergoing intraoperative abdominal aortic balloon occlusion during cesarean section

Background

This retrospective study aimed to compare the clinical outcomes of parturients with placenta previa (PP) and placenta accreta (PA) according to their severity, when they were managed with intraoperative abdominal aortic balloon occlusion (IAABO) during cesarean section.

Methods

We retrospectively examined 57 cases of PP and suspicion for PA in which IAABO was performed during cesarean section between April 2014 and June 2016. Based on preoperative examination and clinical risk factors, patients were divided into the low suspicion PA group and the high suspicion PA group. We compared the demographic characteristics, methods of anesthesia, intra- and postoperative parameters, and maternal and neonatal outcomes.

Results

The two groups showed similar demographic characteristics and intraoperative outcomes. Four women underwent cesarean hysterectomy. Eight neonates were admitted to the neonatal intensive care unit and three did not survive. Neonatal Apgar scores were significantly higher in the low suspicion PA group. Eight patients experienced postoperative femoral artery thrombosis and one patient complicated hematoma in the front wall of the common femoral artery. Patients who received neuraxial anesthesia showed significantly lower intraoperative blood loss, lower intraoperative, postoperative and total blood transfusion and shorter surgery than patients who received general anesthesia.

Conclusions

Our data suggested that the severity of aberrant placental position does not affect intraoperative blood loss during a cesarean section while the IAABO is performed. We propose that neuraxial anesthesia is preferred for conducting these surgeries without contraindications.

Comparing outcomes after peripheral nerve block versus general anesthesia for lower extremity amputation: a nationwide exploratory retrospective cohort study in Japan

Background and objectives

The health benefits of peripheral nerve block (PNB) on postoperative complications after lower extremity amputation (LEA) compared with general anesthesia (GA) remains controversial. We performed a retrospective propensity score-matched cohort analysis to compare major outcomes after LEA with PNB versus GA.

Materials and methods

We used a nationwide inpatient database in Japan to compare patient outcomes after LEA with PNB versus GA from 2010 to 2016. Our primary outcome was 30-day mortality after LEA. The incidence of composite morbidity from life-threatening complications and of delirium within 30 days after LEA were secondary outcomes. We conducted propensity score-matched analyses of patients who underwent below knee or foot amputation using 36 covariates. Logistic regression analyses fitted with generalized estimating equations were performed to calculate ORs and their 95% CIs.

Results

Of 11 796 patients, 747 received PNB and 11 049 received GA. After one-to-four propensity score matching, 747 patients were included in the PNB group and 2988 in the GA group. The adjusted ORs for postoperative mortality, composite morbidity and delirium within 30 days after LEA were 1.11 (95% CI 0.75 to 1.64), 1.15 (95% CI 0.85 t o1.56) and 0.75 (95% CI 0.57 to 0.98), respectively, for the PNB group with reference to the GA group.

Conclusions

There was no significant difference between groups in 30-day mortality or composite morbidity. The PNB group showed a significantly lower risk of postoperative delirium than the GA group. Our findings suggest that PNB may have advantages over GA in preventing postoperative delirium among patients undergoing LEA.

Is there a benefit to additional neuroaxial anesthesia in open nephrectomy? A prospective NSQIP propensity score analysis

INTRODUCTION

Neuroaxial (i.e., spinal, regional, epidural) anesthesia has been shown to be associated with reduced readmission rate, decreased hospital stay, and decreased overall complication rate in orthopedic and gynecologic surgery. Our aim was to identify differences in intra- and postoperative complications, length of stay and readmission rates in open nephrectomy patients managed with neuroaxial anesthesia.

MATERIALS AND METHODS

Utilizing National Surgical Quality Inpatient Program (NSQIP) database, we identified patients who have undergone an open nephrectomy between 2014 and 2017. Patients were further subdivided based on anesthesia modality. We used the propensity score-matching (PSM) method to adjust for baseline differences among patients who received general anesthesia alone and those with additional neuroaxial anesthesia. Using step-wise multivariable logistic regression, we identified preoperative and intraoperative predictors associated with 30-day procedure-related readmission, complications, and postoperative length of stay.

RESULTS

Out of 3,633 patients identified, 2346 patients met our inclusion and exclusion criteria. There was no difference in baseline characteristics after propensity score matching between general and additional neuroaxial anesthesia. Postoperative outcomes including: procedure-related readmission, rate of reoperation, operative time, all complications were similar between the groups. Adjuvant neuroaxial anesthesia group did experience a prolonged postoperative hospital stay that was statistically significant as compared to patients with general anesthesia alone [5.3 (3.5) days vs 4.8 (2.9) days, p = 0.007]. Compared to GA alone after multivariable logistic regression, neuroaxial anesthesia was not statistically significant for readmission (p = 0.909), any complication (p = 0.505), but did showed increased odds ratio of prolonged postoperative stay [aOR 1.107, 95% CI 1.042-1.176, p = 0.001] after adjusting for multiple factors.

CONCLUSION

Using 2014-2017 NSQIP database, we were able to demonstrate no additional reduction in complication or readmission rate in patients with neuroaxial anesthesia as compared to general anesthesia alone. Furthermore, patients who did receive neuroaxial anesthesia experienced a longer postoperative course.

Effect of Anesthetic Technique on the Occurrence of Acute Kidney Injury after Total Knee Arthroplasty

Recent studies have reported the advantages of spinal anesthesia over general anesthesia in orthopedic patients. However, little is known about the relationship between acute kidney injury (AKI) after total knee arthroplasty (TKA) and anesthetic technique. This study aimed to identify the influence of anesthetic technique on AKI in TKA patients. We also evaluated whether the choice of anesthetic technique affected other clinical outcomes. We retrospectively reviewed medical records of patients who underwent TKA between January 2008 and August 2016. Perioperative data were obtained and analyzed. To reduce the influence of potential confounding factors, propensity score (PS) analysis was performed. A total of 2809 patients and 2987 cases of TKA were included in this study. A crude analysis of the total set demonstrated a significantly lower risk of AKI in the spinal anesthesia group. After PS matching, the spinal anesthesia group showed a tendency for reduced AKI, without statistical significance. Furthermore, the spinal anesthesia group showed a lower risk of pulmonary and vascular complications, and shortened hospital stay after PS matching. In TKA patients, spinal anesthesia had a tendency to reduce AKI. Moreover, spinal anesthesia not only reduced vascular and pulmonary complications, but also shortened hospital stay.