Cost-effectiveness of general anesthesia vs spinal anesthesia in fast-track abdominal benign hysterectomy

A Comparison of the Effects of Different Positive End-Expiratory Pressure Levels on Respiratory Parameters During Prone Positioning Under General Anaesthesia: A Randomized Controlled Trial

Background and objective In general anesthesia, for certain surgical procedures in the prone position, patients often face increased airway pressures, reduced pulmonary and thoracic compliance, and restricted chest expansion, all of which can affect venous return and cardiac output, impacting overall hemodynamic stability. Positive end-expiratory pressure (PEEP) is used to address these issues by improving lung recruitment and ventilation while reducing stress on lung units. However, different PEEP levels also present risks such as increased parenchymal strain, higher pulmonary vascular resistance, and impaired venous return.  Proper positioning and frequent monitoring are key to ensuring adequate oxygenation and minimizing complications arising from prolonged periods in the prone position. This study aimed to evaluate the effects of different PEEP levels (0 cmH2O, 5 cmH2O, and 10 cmH2O) in the prone position to determine the optimal setting for balancing improved oxygenation and lung recruitment against potential adverse effects. The goal is to refine individualized PEEP strategies beyond what is typically outlined in standard PEEP tables. We endeavored to examine the impact of different PEEP levels during pressure-controlled ventilation (PCV) on arterial oxygenation, respiratory parameters, and intraoperative blood loss in patients undergoing spine surgery in a prone position under general anesthesia. Methodology This randomized, single-blinded, controlled study enrolled 90 patients scheduled for elective spine fixation surgeries. Patients were randomized into three groups: Group A (PEEP 0), Group B (PEEP 5), and Group C (PEEP 10). Standardized anesthesia protocols were administered to all groups, with ventilation set to pressure-controlled mode at desired levels. PEEP levels were adjusted according to group allocation. Arterial blood gases were measured before induction, 30 minutes after prone positioning, and 30 minutes post-extubation. Arterial line insertion was performed, and dynamic compliance, mean arterial pressure (MAP), heart rate (HR), and intraoperative blood loss were recorded at regular intervals. Data were analyzed using SPSS Statistics version 21 (IBM Corp., Armonk, NY). Results Arterial oxygenation was significantly higher in Groups B (PEEP 5) and C (PEEP 10) compared to Group A (PEEP 0) at both 30 minutes post-intubation and post-extubation. Specifically, at 30 minutes post-intubation, arterial oxygenation was 142.26 ±24.7 in Group B and 154.9 ±29.88 in Group C, compared to 128.18 ±13.3 in Group A (p=0.002). Similarly, post-extubation arterial oxygenation levels were 105.1 ±8.28 for Group B and 115.46 ±15.2 for Group C, while Group A had levels of 97.07 ±9.90 (p<0.001). MAP decreased significantly in Groups B and C compared to Group A. Dynamic compliance was also improved in Groups B and C. Furthermore, intraoperative blood loss was notably lower in Group C (329.66 ±93.93) and Group B (421.16 ±104.52) compared to Group A (466.66 ±153.76), and these differences were statistically significant. Conclusions Higher levels of PEEP (10 and 5 cmH2O) during prone positioning in spine surgery improve arterial oxygenation, dynamic compliance, and hemodynamic stability while reducing intraoperative blood loss. These findings emphasize the importance of optimizing ventilatory support to enhance patient outcomes during prone-position surgeries.

Comparison of percutaneous nephrolithotomy under epidural anesthesia versus general anesthesia: A randomized prospective study

Introduction:

PCNL has revolutionized the treatment of renal calculi putting almost an end to the era of open stone surgery. The procedure can safely be carried out under general anesthesia (GA) or regional anesthesia viz. spinal anesthesia (SA), epidural anesthesia (EA) or combined spinal and epidural anesthesia (CSE).

Aims and Objectives:

We evaluated the surgical outcome after PCNL in two groups of patients randomly divided to undergo procedure under GA or EA.

Patients and Methods:

Two hundred and thirty patients with American Society of Anesthesiologists (ASA) score <3 were randomly divided into two groups according to the type of anesthesia: i.e. GA (n=110) or EA (n=120). All patients underwent PCNL in prone position. Puncture was done using Bulls eye technique under fluoroscopic guidance and tract dilated using serial dilators up to 24Fr-28 Fr. Demographics, perioperative and postoperative parameters were noted and data analysed.

Results:

The two groups were comparable in terms of mean age, distribution of stone location, and stone burden. The stone free rate was 90.9% in GA group and 89.2% in EA group and the difference was statistically insignificant (P= 0.659). The requirement for auxiliary procedures was similar between the two groups. A significant difference in pain score was seen in favor of EA group during early post-operative period (P< 0.05).

Conclusion:

It seems that PCNL can be performed safely and effectively under regional epidural anesthesia with results comparable to general anesthesia with the added advantage of less immediate postoperative pain and analgesic requirement.

Cost-Effectiveness of Propofol (Diprivan) Versus Inhalational Anesthetics to Maintain General Anesthesia in Noncardiac Surgery in the United States

OBJECTIVES

It is not known whether using propofol total intravenous anaesthesia (TIVA) to reduce incidence of postoperative nausea and vomiting (PONV) is cost-effective. We assessed the economic impact of propofol TIVA versus inhalational anesthesia in adult patients for ambulatory and inpatient procedures relevant to the US healthcare system.

METHODS

Two models simulate individual patient pathways through inpatient and ambulatory surgery with propofol TIVA or inhalational anesthesia with economic inputs from studies on adult surgical US patients. Efficacy inputs were obtained from a meta-analysis of randomized controlled trials. Probabilistic and deterministic sensitivity analyses assessed the robustness of the model estimates.

RESULTS

Lower PONV rate, shorter stay in the post-anesthesia care unit, and reduced need for rescue antiemetics offset the higher costs for anesthetics, analgesics, and muscle relaxants with propofol TIVA and reduced cost by 11.41 ± 10.73 USD per patient in the inpatient model and 11.25 ± 9.81 USD in the ambulatory patient model. Sensitivity analyses demonstrated strong robustness of the results.

CONCLUSIONS

Maintenance of general anesthesia with propofol was cost-saving compared to inhalational anesthesia in both inpatient and ambulatory surgical settings in the United States. These economic results support current guideline recommendations, which endorse propofol TIVA to reduce PONV risk and enhance postoperative recovery.

Identification and economic burden of main adverse events of nerve injuries caused by regional anesthesia: a systematic review

BACKGROUND AND OBJECTIVES

Anesthesiologists and hospitals are increasingly confronted with costs associated with the complications of Peripheral Nerve Blocks (PNB) procedures. The objective of our study was to identify the incidence of the main adverse events associated with regional anesthesia, particularly during anesthetic PNB, and to evaluate the associated healthcare and social costs.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic search on EMBASE and PubMed with the following search strategy: ("regional anesthesia" OR "nerve block") AND ("complications" OR "nerve lesion" OR "nerve damage" OR "nerve injury"). Studies on patients undergoing a regional anesthesia procedure other than spinal or epidural were included. Targeted data of the selected studies were extracted and further analyzed.

RESULTS

Literature search revealed 487 articles, 21 of which met the criteria to be included in our analysis. Ten of them were included in the qualitative and 11 articles in the quantitative synthesis. The analysis of costs included data from four studies and 2,034 claims over 51,242 cases. The median claim consisted in 39,524 dollars in the United States and 22,750 pounds in the United Kingdom. The analysis of incidence included data from seven studies involving 424,169 patients with an overall estimated incidence of 137/10,000.

CONCLUSIONS

Despite limitations, we proposed a simple model of cost calculation. We found that, despite the relatively low incidence of adverse events following PNB, their associated costs were relevant and should be carefully considered by healthcare managers and decision makers.

Intravenous magnesium sulfate for postoperative analgesia after abdominal hysterectomy under spinal anesthesia: a randomized, double-blind trial

Background and objectives

Abdominal Hysterectomy (AH) is associated with significant inflammatory response and can result in moderate to severe postoperative pain. This study aimed to evaluate the efficacy of magnesium infusion in reducing postoperative pain and analgesic consumption after AH under spinal anesthesia with Intrathecal Morphine (ITM).

Method

Eighty-six patients were included in this clinical, controlled, randomized, double-blind study. Patients received in Group Mg, MgSO₄ 50 mg kg⁻¹ for 15 minutes followed by 15 mg kg⁻¹ h⁻¹ until the end of the surgery; and in Group C, (control) the same volume of isotonic saline. Both groups received 100 μg of ITM. All patients received dipyrone + ketoprofen intraoperatively and postoperatively, and dexamethasone intraoperatively only. We evaluated the intensity of pain, tramadol consumption, and adverse events 24 hours postoperatively.

Results

Serum magnesium concentrations were higher in Group Mg at the end, and one hour after the operation (p = 0.000). Postoperative pain scores were reduced in Group Mg at 6 hours at rest and on movement (p < 0.05). Tramadol consumption did not show a statistically significant difference between Group Mg and Group C (15.5 ± 36.6 mg and 29.2 ± 67.8 mg respectively, p = 0.53). Hemodynamic variables, the incidence of pruritus, nausea, and vomiting were similar in the two groups.

Conclusion

Infusion of MgSO₄ during AH undergoing spinal anesthesia with ITM reduced at 6 hours at rest and on movement. More studies should be performed to evaluate the potential antinociceptive effect of MgSO₄ in scenarios where a multimodal analgesia approach was employed.

Opioid-Free Anesthesia in the Perioperative Setting-A Preliminary Retrospective Matched Cohort Study

INTRODUCTION

Anesthesiologists have long used multimodal analgesia for effective pain control. Opioid-sparing anesthetics are gaining popularity among practitioners in light of increasing concerns for both immediate opioid side effects and the long-term opioid misuse among susceptible patients. Currently, there is a critical gap in knowledge regarding outcomes after an opioid-free anesthetic (OFA) during general anesthesia. We hypothesized that an opioid-free general anesthetic will not be inferior to a traditional opioid anesthetic (OA) as measured by the perioperative outcomes of postanesthesia care unit (PACU) duration, 12-hour postoperative summed pain intensity (SPI12) scores, total morphine equivalent doses (MEDs) utilized in the 12-hour postoperative inpatient (MED12) and total MEDs utilized in the 90-day outpatient periods (MED90).

MATERIALS AND METHODS

Patients were included if they were  ≥18 years old, met criteria for American Society of Anesthesiologists classification I-IV, received general endotracheal anesthesia from a single anesthesia provider for a surgical operation in 2016, did not receive intraoperative administration of opioids, and were recovered in the PACU. A total of 25 patients were included in the OFA group and 29 control patients in the OA group (n = 54). A retrospective chart review of intraoperative records, perioperative pain scores, and medication utilization (inpatient and outpatient) was performed to obtain the data for the analysis of the primary outcomes.

RESULTS

In both OFA and OA groups, the continuous outcomes were not normally distributed. Subsequent bivariate tests of the indicated OA versus OFA age (d = 0.58), surgery duration (d = 0.24), and preoperative pain score (d = 0.51) warranted inclusion in the multinomial regression. Surgical duration was not significantly associated with the primary outcomes. However, the continuous variables of age and preoperative Defense and Veterans Pain Rating Scale score were associated with differences in primary outcomes. Every 1-year increase in the age was associated with a 5.06 increase in SPI12 and 5.73 mg increase in MED12. Every 1-point increase in the preoperative Defense and Veterans Pain Rating Scale score was associated with an 8.45 minutes increase in PACU duration, 11.25 increase in SPI12, 17.85 mg increase in MED12, and 20.83 mg increase in MED90. In regard to the primary outcomes, there was a lack of significant differences between the OFA and OA groups in all outcomes (PACU duration, mean SPI12, MED12, and MED90).

CONCLUSIONS

To our knowledge, this is the first matched cohort study directly comparing an OFA with a traditional anesthetic for general anesthesia in a wide range of surgical and clinical scenarios. There was no significant difference in SPI12 between the OFA group and OA group, suggesting that patients' subjective pain was similar immediately after surgery whether or not they received intraoperative opioids. Concurrently, no "catch-up" effect was observed as the PACU duration; MED12 and MED90 were not different between the OFA and OA groups. However, there were many covariates identified in this study because of the small sample size or each group. Additional research is needed to explore if these findings can be extrapolated to a larger more heterogeneous population. Our preliminary work suggests that eliminating patient exposure to opioids in the intraoperative period does not have a deleterious effect on perioperative patient outcomes.

Safety and Efficacy of Transurethral Resection of Bladder Tumor Comparing Spinal Anesthesia with Spinal Anesthesia with an Obturator Nerve Block: A Systematic Review and Meta-analysis

Aims: To investigate whether spinal anesthesia with an obturator nerve block (SA+ONB) can be effectively used for transurethral resection of bladder tumor (TURBT) during the coronavirus disease 2019 (COVID-19) pandemic to improve patient outcomes while also avoiding aerosol-generating procedures (AGPs). We aimed to compare outcomes of TURBTs using spinal anesthesia (SA) alone vs SA+ONB in terms of rates of obturator reflex, bladder perforation, incomplete tumor resection, tumor recurrence, and local anesthetic toxicity. Methods: We conducted a comprehensive search of electronic databases (MEDLINE, PUBMED, EMBASE, CINAHL, CENTRAL, SCOPUS, Google Scholar, and Web of Science), identifying studies comparing the outcomes of TURBT using SA vs spinal with an ONB. The Cochrane risk-of-bias tool for randomized-controlled trials (RCTs) and the Newcastle-Ottawa scale for observational studies were used to assess the included studies. Random effects modeling was used to calculate pooled outcome data. Results: Four RCTs and three cohort studies were identified, enrolling a total of 448 patients. The use of SA+ONB was associated with a significantly reduced risk of obturator reflex (p < 0.00001), bladder perforation (p = 0.02), incomplete resection (p < 0.0001), and 12-month tumor recurrence (p = 0.005). ONB was not associated with an increased risk of local anesthetic toxicity (0/159). Conclusion: Our meta-analysis suggests that TURBT using SA+ONB is superior to the use of SA alone. During the COVID-19 pandemic, where avoidance of AGPs such as a general anesthesia is paramount, the use of an ONB with SA is essential for the safety of both patients and staff without compromising care. Further high-quality RCTs with adequate sample sizes are required to compare the different techniques of ONB as well as comparing this method with general anesthesia with complete neuromuscular blockade.

Using critical care physicians to deliver anesthesia and boost surgical caseload in austere environments: the Critical Care General Anesthesia Syllabus (CC GAS)

Background

Despite an often severe lack of surgeons and surgical equipment, the rate-limiting step in surgical care for the nearly five billion people living in resource-limited areas is frequently the absence of safe anesthesia. During disaster relief and surgical missions, critical care physicians (CCPs), who are already competent in complex airway and ventilator management, can help address the need for skilled anesthetists in these settings.

Methods

We provided a descriptive analysis that CCPs were trained to provide safe general anesthesia, monitored anesthesia care (MAC), and spinal anesthesia using a specifically designed and simple syllabus.

Results

Six CCPs provided anesthesia under the supervision of a board-certified anesthesiologist for 58 (32%) cases of a total of 183 surgical cases performed by a surgical mission team at St. Luc Hospital in Port-au-Prince, Haiti in 2013, 2017, and 2018. There were no reported complications.

Conclusions

Given CCPs' competencies in complex airway and ventilator management, a CCP, with minimal training from a simple syllabus, may be able to act as an anesthesiologist-extender and safely administer anesthesia in the austere environment, increasing the number of surgical cases that can be performed. Further studies are necessary to confirm our observation.

Cost-Effectiveness Research in Anesthesiology

Perioperative interventions aimed at decreasing costs and improving outcomes have become increasingly popular in recent years. Anesthesiologists are often faced with a choice among different treatment strategies with little data available on the comparative cost-effectiveness. We performed a systematic review of the English language literature between 1980 and 2014 to identify cost-effectiveness analyses of anesthesiology and perioperative medicine interventions. We excluded interventions related to critical care or pediatric anesthesiology, and articles on interventions not normally ordered or performed by anesthesiologists. Of the >5000 cost-effectiveness analyses published to date, only 28 were applicable to anesthesiology and perioperative medicine and met inclusion criteria. Multidisciplinary interventions were the most cost-effective overall; 8 of 8 interventions were "dominant" (improved outcomes, reduced cost) or cost-effective, including accelerated, standardized perioperative recovery pathways, and perioperative delirium prevention bundles. Intraoperative measures were dominant in 3 of 5 cases, including spinal anesthesia for benign abdominal hysterectomy. With regard to prevention of perioperative infection, methicillin-resistant Staphylococcus aureus (MRSA) decolonization was dominant or cost-effective in 2 of 2 studies. Three studies assessing various antibiotic prophylaxis regimens had mixed results. Autologous blood donation was not found to be cost-effective in 5 of 7 studies, and intraoperative cell salvage therapy was also not cost-effective in 2 of 2 reports. Overall, there remains a paucity of cost-effectiveness literature in anesthesiology, particularly relating to intraoperative interventions and multidisciplinary perioperative interventions. Based on the available studies, multidisciplinary perioperative optimization interventions such as accelerated, standardized perioperative recovery pathways, and perioperative delirium prevention bundles tended to be most cost-effective. Our review demonstrates that there is a need for more rigorous cost-effective analyses in many areas of anesthesiology and that anesthesiologists should continue to lead collaborative, multidisciplinary efforts in perioperative medicine.

Guild interests: an insidious threat to professionalism in obstetrics and gynecology

Powerful incentives now exist that could subordinate professionalism to guild self-interest. How obstetrician-gynecologists respond to these insidious incentives will determine whether guild self-interests will define our specialty. We provide ethically justified, practical guidance to obstetrician-gynecologists to prevent this ethically unacceptable outcome. We describe and illustrate 2 major incentives to subordinating professionalism to guild self-interest: demands for productivity; and compliance and regulatory pressures. We then set out the professional responsibility model of ethics in obstetrics and gynecology to guide obstetrician-gynecologists in responding to these incentives so that they preserve professionalism. Obstetrician-gynecologists should identify guild interests affecting their group practices, set ethically justified limits on self-sacrifice, and prevent incremental drift toward dominance of guild self-interests over professionalism. Guild self-interests could succeed in undermining professionalism, but only if obstetrician-gynecologists allow this to happen. When guild self-interest becomes the deciding factor in patient care, professionalism withers and insidious incentives flourish.

Impact of perioperative care on the post-operative recovery of women undergoing surgery for gynaecological tumours

To assess perioperative care in patients undergoing abdominal surgery for gynaecological tumours and how it relates to post-operative (PO) complications and oral PO feeding. Ninety-one women undergoing major abdominal surgery for gynaecological tumours were enrolled. Data included mechanical bowel preparation (MBP), prescribed diet, length of fast, start date of oral diet and progression of food consistency, anaesthetic technique, use of opioids and intravenous hydration (IH). Outcomes evaluated were nausea, vomiting and abdominal distension. The median pre-operative length of fast was 11.4 h. PO digestive complications occurred in 46.2% of the patients. Median intraoperative total IH and crystalloids were significantly higher in patients with abdominal distension during the first and second PO day. MBP with mannitol implied greater intraoperative IH and was significantly associated with a higher incidence of immediate PO nausea. Post-operative IH was also associated with gastrointestinal complications. The best cut-off point for the cumulative fluid load PO for determining a longer PO hospital stay was 4 L. Performing MBP before surgery and excessive IH are factors related to major digestive complications in our study population. Changes in pre-operative fasting time and PO refeeding should be considered to reduce the gastrointestinal complications and PO recovery time.

Enhanced recovery pathways in abdominal gynecologic surgery: a systematic review and meta-analysis

INTRODUCTION

Enhanced recovery pathways have been widely accepted and implemented for different types of surgery. Their overall effect in abdominal gynecologic surgery is still underdetermined. A systematic review and meta-analysis were performed to provide an overview of current evidence and to examine their effect on postoperative outcomes in women undergoing open gynecologic surgery.

MATERIAL AND METHODS

Searches were conducted using Embase, Medline, CINAHL, and the Cochrane Library up to 27 June 2014. Reference lists were screened to identify additional studies. Studies were included if at least four individual items of an enhanced recovery pathway were described. Outcomes included length of hospital stay, complication rates, readmissions, and mortality. Quantitative analysis was limited to comparative studies. Effect sizes were presented as relative risks or as mean differences (MD) with 95% confidence intervals (CI).

RESULTS

Thirty-one records, involving 16 observational studies, were included. Diversity in reported elements within studies was observed. Preoperative education, early oral intake, and early mobilization were included in all pathways. Five studies, with a high risk of bias, were eligible for quantitative analysis. Enhanced recovery pathways reduced primary (MD -1.57 days, 95% CI CI -2.94 to -0.20) and total (MD -3.05 days, 95% CI -4.87 to -1.23) length of hospital stay compared with traditional perioperative care, without an increase in complications, mortality or readmission rates.

CONCLUSION

The available evidence based on a broad range of non-randomized studies at high risk of bias suggests that enhanced recovery pathways may reduce length of postoperative hospital stay in abdominal gynecologic surgery.

Effect of Two Different Doses of Dexmedetomidine as Adjuvant in Bupivacaine Induced Subarachnoid Block for Elective Abdominal Hysterectomy Operations: A Prospective, Double-blind, Randomized Controlled Study

OBJECTIVES

Improvements in perioperative pain management for lower abdominal operations has been shown to reduce morbidity, induce early ambulation, and improve patients' long-term outcomes. Dexmedetomidine, a selective alpha-2 agonist, has recently been used intrathecally as adjuvant to spinal anesthesia to prolong its efficacy. We compared two different doses of dexmedetomidine added to hyperbaric bupivacaine for spinal anesthesia. The primary endpoints were the onset and duration of sensory and motor block, and duration of analgesia.  .

METHODS

A total of 100 patients, aged 35-60 years old, assigned to have elective abdominal hysterectomy under spinal anesthesia were divided into two equally sized groups (D5 and D10) in a randomized, double-blind fashion. The D5 group was intrathecally administered 3ml 0.5% hyperbaric bupivacaine with 5µg dexmedetomidine in 0.5ml of normal saline and the D10 group 3ml 0.5% bupivacaine with 10µg dexmedetomidine in 0.5ml of normal saline. For each patient, sensory and motor block onset times, block durations, time to first analgesic use, total analgesic need, postoperative visual analogue scale (VAS) scores, hemodynamics, and side effects were recorded.  .

RESULTS

Although both groups had a similar demographic profile, sensory and motor block in the D10 group (p<0.050) was earlier than the D5 group. Sensory and motor block duration and time to first analgesic use were significantly longer and the need for rescue analgesics was lower in the D10 group than the D5 group. The 24-hour VAS score was significantly lower in the D10 group (p<0.050). Intergroup hemodynamics were comparable (p>0.050) without any appreciable side effects.  .

CONCLUSION

Spinal dexmedetomidine increases the sensory and motor block duration and time to first analgesic use, and decreases analgesic consumption in a dose-dependent manner.

Example of cost calculations for an operating room and a post-anaesthesia care unit

OBJECTIVE

The aim of this study was to evaluate the cost of an operating room using data from our hospital. Using an accounting-based method helped us.

METHODS

Over the year 2012, the sum of direct and indirect expenses with cost sharing expenses allowed us to calculate the cost of the operating room (OR) and of the post-anaesthesia care unit (PACU).

RESULTS

The cost of the OR and PACU was €10.8 per minute of time offered. Two thirds of the direct expenses were allocated to surgery and one third to anaesthesia. Indirect expenses were 25% of the direct expenses. The cost of medications and single use medical devises was €111.45 per anaesthesia. The total cost of anaesthesia (taking into account wages and indirect expenses) was €753.14 per anaesthesia as compared to the total cost of the anaesthesia. The part of medications and single use devices for anaesthesia was 14.8% of the total cost.

CONCLUSION

Despite the difficulties facing cost evaluation, this model of calculation, assisted by the cost accounting controller, helped us to have a concrete financial vision. It also shows that a global reflexion is necessary during financial decision-making.

The development of fast-track principles in gynecological surgery

Fast-track is a multimodal strategy aimed at reducing the physiological burden of surgery to achieve an enhanced postoperative recovery. The strategy combines unimodal evidence-based interventions in the areas of preoperative preparation, anesthesia, surgical factors and postoperative care. The advantages of fast-track most likely extend to gynecology, although so far have scarcely been reported. This review summarizes current evidence concerning use of fast-track in general and in gynecological surgery. The main findings of this review are that there are benefits within elective gynecological surgery, but studies of quality of life, patient satisfaction and health economics in elective surgery are needed. Studies of fast-track within the field of non-elective gynecological surgery are lacking. Widespread education is needed to improve the rate of implementation of fast-track. Close involvement of the entire surgical team is imperative to ensure a structured perioperative care aiming for enhanced postoperative recovery.