Obesity and Regional Anesthesia

Intraoperative lidocaine infusion as a sole analgesic agent versus morphine in laparoscopic gastric bypass surgery

Background

The aim of this study was to assess the effect of intra-operative intra-venous (IV) lidocaine infusion compared to IV morphine, on the post-operative pain at rest, the intra-operative and post-operative morphine requirements, the sedation and the Modified Aldrete scores in the post-anesthesia care unit (PACU), the hemodynamic parameters; mean values of the mean blood pressure (MBP) and the heart rate (HR), the peri-operative changes in the SpO2, and the respiratory rate (RR) in laparoscopic Roux-en-y gastric bypass. Sixty patients ˃ 18 years old, with body mass index (BMI) ˃ 35 kg/m2, American Society of Anesthesiologists (ASA) physical status II or III, were randomly divided into 2 groups: the lidocaine (L) group patients received intra-operative IV lidocaine infusion, and the morphine (M) group patients received intra-operative IV morphine.

Results

The post-operative numeric pain rating scale (NPRS) at rest was statistically significant less in group L than in group M patients, in the post-operative 90 min in the PACU. This was reflected on the post-operative morphine requirements in the PACU, as 26.6% of patients in group M required morphine with a mean total dose of 10.8 mg. The mean values of the MBP and HR recorded after intubation were comparable between patients of both groups, indicating attenuation of the stress response to endotracheal intubation by both lidocaine and morphine. However, the mean values of the MBP and HR recorded after extubation were statistically significant lower in patients of group L, indicating the attenuation of the stress response to extubation by lidocaine. Patients in group M showed statistically significant lower mean values of the MBP; before pneumoperitoneum and after 15 min from the pneumoperitoneum, this was reflected on statistically significant higher mean values of the HR. Patients in group L showed statistically significant lower mean values of the MBP and the HR; at 30 and 45 min from the pneumoperitoneum. Patients in group L showed statistically significant lower mean values of the MBP; 60 min from the pneumoperitoneum, after release of pneumoperitoneum and in the PACU. Patients of both groups showed comparable mean values of the HR after 60 min from the pneumoperitoneum, after release of the pneumoperitoneum and in the PACU. No patient in either groups developed post-operative respiratory depression in the PACU. Patients in group L showed statistically significant higher median sedation score, which was reflected on statistically but not clinically significant less Modified Aldrete score in patients of group L.

Conclusions

In morbid obese patients, the intra-operative IV lidocaine infusion offered post-operative analgesia in the PACU, on the expense of a higher sedation score, which didn’t affect the Modified Aldrete score clinically, with attenuation of the stress response to endotracheal intubation and extubation.

Trial registrations

FMASU R16/2021. Registered 1st February 2021, with Clinical Trials Registry (NCT05150756) on 10/08/2021.

Comparing the Effects of General Versus Regional Anesthesia on Postoperative Mortality in Total and Partial Hip Arthroplasty

Purpose

Total hip arthroplasty (THA) and partial hip arthroplasty (PHA) are performed in patients with hip joint dysfunction such as osteoarthritis or hip fractures and are associated with complications including mortality. There is a lack of evidence in the literature regarding whether the type of anesthesia (regional vs. general) is associated with increased postoperative mortality in patients undergoing hip arthroplasty. The present study compares early postoperative mortality between general or regional anesthesia administered to patients undergoing either THA or PHA.

Methods

A retrospective cohort was assembled using the 2015-2016 American College of Surgeons National Surgical Quality Improvement Program database. Adult patients undergoing hip arthroplasty under general or regional anesthesia were included. Patients were excluded if receiving any other type of anesthesia, as well as having an American Society of Anesthesiologists (ASA) physical status classification score ≥ 4, preoperative acute renal failure, severe congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), or ascites. Adjusted odds of 30 days all-cause postoperative mortality according to the type of anesthesia were estimated by fitting multiple logistic regression models that included potential confounders and effect modifiers.

Results

A total of 60,897 patients were included in the study. Given that the interaction between the type of anesthesia and the type of arthroplasty was statistically significant, separated models were fitted for each type of arthroplasty. There was no evidence of an association between type of anesthesia and postoperative mortality in hip arthroplasty patients regardless of whether the arthroplasty was partial (odds ratio {OR} = 0.85; confidence interval {CI} 0.59-1.22) or total (OR = 0.68; CI 0.43-1.08).

Conclusion

The overall early postoperative mortality in adult hip arthroplasty patients is low in the absence of risk factors such as severe CHF, COPD, ascites, acute renal failure, and ASA score of 4 or higher. Our findings suggest there is no association between the type of anesthesia received (general vs. regional) and early postoperative mortality rates in patients undergoing hip arthroplasty, regardless of type (total vs. partial).

Finding the body mass index cutoff for hospital readmission after ambulatory hernia surgery

BACKGROUND

The suitability of ambulatory surgery in obese patients remains controversial. This study aimed to investigate the "cutoff" value of body mass index (BMI) associated with increased likelihood of hospital readmissions within the first 24 hours of surgery in patients undergoing ambulatory hernia repair.

MATERIALS AND METHODS

The study used data from the 2012-2016 American College of Surgeons National Surgical Quality Improvement (ACS-NSQIP). Cochran Armitage trend tests were conducted to assess progression in rates hospital readmissions across categories of patient BMI. The minimum p-value method, Kolmogorov-Smirnov goodness of fit tests, logistic regression, and receiver-operating characteristic (ROC) curve analyses were used to investigate the cutoff of patient BMI indicative of increased likelihood of readmissions.

RESULTS

A total of 214,125 ambulatory hernia repair cases were identified. Of those, 908 patients (0.42%) had an unexpected hospital admission within the first 24 hours after surgery. The readmission rates did not significantly increase across the categories of BMI. However, some of the reasons for readmission significantly differed by BMI category. Logistic regression analysis revealed no statistically significant association between BMI and hospital readmissions (odds ratio [95% Cl], 0.96 [0.91-1.02] P = .179). An optimal BMI threshold predictive of an increased likelihood of hospital readmissions was not identifiable by any of the statistical methods used.

CONCLUSIONS

Although reasons for readmission differed by BMI category, there is no clear cutoff value of BMI associated with increased hospital readmission within the first 24 hours after surgery.

Echo-Guided Differential Popliteal Block in an Obese Patient With Intractable Painful Leg Ulcer for Early Discharge in Day Surgery

Pain management is extremely important in day surgery, and it is one of the limiting factors for this type of procedures. Locoregional anesthesia is strongly recommended for day surgery; nevertheless, it could be very difficult to localize nerve position especially in obese patients. Furthermore, a complete nerve blockade could result in a delayed discharge. We present a case of analgesic ultrasound-guided block of tibial and common peroneal nerves in the popliteal fossa without any motor function involvement in an obese patient undergoing debridement of an infected lower limb ulcer; all previous attempts of surgical debridement in day surgery with topical anesthetics had failed because of discomfort due to pain. Our aim was to ensure an optimal degree of analgesia and, at the same time, to save motor function in order to make early discharge possible. We used 15 mL ropivacaine 0.375% to obtain a differential block, taking advantage of sensitive fibers selectivity of ropivacaine. Surgical debridement was performed successfully. Our peripheral blockade was able to provide significantly prolonged analgesia without motor block that guaranteed a safe and early discharge according to the Post Anesthetic Discharge Scoring System. The satisfaction expressed by the patient and her comfort during the procedure support the choice of this approach for intractable painful ulcers of lower limb.

Obesity in regional anesthesia--a risk factor for peripheral catheter-related infections

BACKGROUND

Obesity is believed to increase the risk of surgical site infections and possibly increase the risk of catheter-related infections in regional anesthesia. We, therefore, analyzed the influence of obesity on catheter-related infections defined within a national registry for regional anesthesia.

METHODS

The German Network for Regional Anesthesia database with 25 participating clinical centers was analyzed between 2007 and 2012. Exactly, 28,249 cases (13,239 peripheral nerve and 15,010 neuraxial blocks) of patients ≥ 14 years were grouped in I: underweight (BMI 13.2-18.49 kg/m(2) , n = 597), II: normal weight (BMI 18.5-24.9 kg/m(2) , n = 9272), III: overweight (BMI 25.0-29.9 kg/m(2) , n = 10,632), and IV: obese (BMI 30.0-70.3 kg/m(2) , n = 7,744). The analysis focused on peripheral and neuraxial catheter-related infections. Differences between the groups were tested with non-parametric ANOVA and chi-square (P < 0.05). Binary logistic regression was used to compare obese, overweight, or underweight patients with normal weight patients. Odds ratios (OR and 95% confidence interval) were calculated and adjusted for potential confounders.

RESULTS

Confounders with significant influence on the risk for catheter-related infections were gender, age, ASA score, diabetes, preoperative infection, multiple skin puncture, and prolonged catheter use. The incidence (normal weight: 2.1%, obese: 3.6%; P < 0.001) and the risk of peripheral catheter-related infection was increased in obese compared to normal weight patients [adjusted OR: 1.69 (1.25-2.28); P < 0.001]. In neuraxial sites, the incidence of catheter-related infections differed significantly between normal weight and obese patients (normal weight: 3.2%, obese: 2.3%; P = 0.01), whereas the risk was comparable [adjusted OR: 0.95 (0.71-1.28); P = 0.92].

CONCLUSION

This retrospective cohort study suggests that obesity is an independent risk factor for peripheral, but not neuraxial, catheter-related infections.

Ultrasound-guided multiple peripheral nerve blocks in a superobese patient

The number of obese patients has increased dramatically worldwide. Morbid obesity is associated with an increased incidence of medical comorbidities and restricts the application choices in anesthesiology. We report a successfully performed combined ultrasound-guided blockade of the femoral, tibial, and common peroneal nerve in a superobese patient. We present a case report of a 31-year-old, ASA-PS II, super obese man (190 kg, 180 cm, BMI: 58 kg/m²) admitted to the emergency department with a type II segmental tibia shaft fracture and ankle dislocation after a vehicle accident. After two failed spinal anesthesia attempts, we decided to apply a femoral block combined with a sciatic block. Femoral blocks were successfully performed with US guided in-plane technique. Separate blocks of the tibial and common peroneal nerves were planned after the sciatic nerve could not be located due to the thick subcutaneous tissue. We performed a tibial nerve block at 2 cm above the popliteal crease and common peroneal nerve at the level of the fibular head with US guided in-plane technique. The blocks were successful and no block-related complications were noted. Ultrasound guidance allows new approaches for multiple peripheral nerve blocks with low local anesthetic doses in obese patients.