Opioid-free versus opioid-sparing anaesthesia in ambulatory total hip arthroplasty: a randomised controlled trial.

BACKGROUND: Enhanced recovery after surgery pathways are essential for ambulatory surgery. They usually recommend lower intraoperative opioid use to avoid opioid-related adverse effects. This has led to opioid-sparing anaesthesia (OSA) techniques, with the extreme approach of opioid-free anaesthesia (OFA) mostly with dexmedetomidine. As evidence is lacking in day-case primary total hip arthroplasty, this study was performed to assess the potential benefits in postoperative analgesia of OFA over OSA. METHODS: In this single-centre, prospective, triple blind study, we randomly allocated 80 patients undergoing day-case primary THA under general anaesthesia. Patients received a total intravenous anaesthesia with a laryngeal mask and multimodal analgesic regimen with non-opioid analgesics. The OSA group received low dose of sufentanil, and the OFA group received dexmedetomidine The primary outcome was the opioid consumption in the first 24 h in oral morphine equivalents (OME). RESULTS: There was no difference in median cumulative OME consumption at 24 h between the OSA and OFA groups (12 [0-25] mg vs 16 [0-30] mg, respectively; P=0.7). Pain scores were similar and low in both groups with comparable walking recovery time. Adverse events were sparse and equivalent in both groups except for dizziness, which was more frequent in the OSA group (P<0.05). CONCLUSIONS: In day-case total hip arthoplasty under general anaesthesia, opioid-free anaesthesia and opioid-sparing anaesthesia both provide early recovery and effective postoperative pain relief. When compared with opioid-sparing anaesthesia, opioid-free anaesthesia does not decrease opioid consumption in the first 24 h. These findings do not suggest any significant benefit from complete intraoperative avoidance of opioids. CLINICAL TRIAL REGISTRATION: NCT0507270.

Combined proximal or distal nerve blocks for postoperative analgesia after total knee arthroplasty: a randomised controlled trial.

BACKGROUND: Many regional anaesthetic techniques have been proposed to manage pain after total knee arthroplasty, but the best approach is unclear. We compared opioid consumption in the first 48 h between two different regional anaesthesia strategies in patients undergoing total knee arthroplasty. METHODS: In this single-centre, prospective study, we randomly allocated 90 patients to a combination of IPACK (interspace between popliteal artery and capsule of the posterior knee), triangle femoral and obturator nerve blocks (distal group), or a combination of sciatic, femoral, obturator, and lateral femoral cutaneous nerve blocks (proximal group). All patients received an opioid-sparing general anaesthesia regimen. The primary outcome was opioid consumption in the first 48 h. Secondary outcomes included opioid consumption in the first 24 h and verbal rating pain scores in the first 48 h. RESULTS: There was no difference in median cumulative oral morphine equivalent consumption at 48 h between the distal and the proximal block groups (33 [18-78] mg vs 30 [22-51] mg, respectively; P=0.29). Median oral morphine equivalent consumption at 24 h was higher in the distal group compared with the proximal group (30 [13-59] vs 15 [0-18], respectively; P<0.001). Verbal rating pain scores were lower in the proximal group compared with the distal group on arrival to the postanaesthesia care unit and at 6 and 12 h. CONCLUSIONS: In patients undergoing total knee arthroplasty under total intravenous general anaesthesia with a multimodal analgesia regimen, proximal nerve blocks resulted in improved pain scores in the first 12 h and reduced opioid consumption in the first 24 h when compared with distal nerve blocks. No difference in pain scores or opioid consumption was seen at 48 h. CLINICAL TRIAL REGISTRATION: NCT04499716.

Diaphragmatic paralysis in obese patients in arthroscopic shoulder surgery: consequences and causes.

PURPOSE: Ambulatory process in arthroscopic shoulder surgery has boomed over past decades. Some anesthetic techniques such as interscalene block (ISB) and its surrogates are associated with diaphragmatic paralysis and might compromise outpatient procedure. HYPOTHESIS: This study aims to assess consequences of diaphragmatic paralysis in obese patients. METHODS: This prospective observational study screened patients with body mass index (BMI) ≥ 30 kg/m2 undergoing acromioplasty or supraspinatus tendon repair. Surgery was performed using brachial plexus block, and the method of brachial plexus block was left at the discretion of attending anesthesiologists. Post-operative hemidiaphragmatic paralysis was evaluated using M-mode ultrasonography and its consequences on patient ventilation were assessed: occurrence of hypoxic episode defined as oxygen saturation less than 90% (by pulse oximeter) in room air, dyspnea and failure of ambulatory procedure. Causes of diaphragmatic paralysis were also analyzed. RESULTS: Ninety-one patients were screened, 82 patients were included in this study and 37 patients (45%) presented diaphragmatic paralysis. Compared to patients without diaphragmatic paralysis, diaphragmatic paralysis was associated with dyspnea [10 (27%) versus 1 (2%); p = 0.0019], occurrence of patients presenting at least one hypoxic episode [6 (16%) versus 1 (2%); p = 0.02] and failure of ambulatory process [10 (27%) versus 1 (2%); p = 0.009]. The combination of axillary and suprascapular nerve blocks, but also low volume ISB, was found to be protective against diaphragmatic paralysis when compared to high volume ISB [Odds ratios 0.0019 (0.001-0.026) and 0.0482 (0.008-0.27), respectively; p < 0.001]. CONCLUSION: In patients with BMI ≥ 30 kg/m2 undergoing arthroscopic shoulder surgery, diaphragmatic paralysis is associated with dyspnea, occurrence of hypoxic episodes and failure of ambulatory procedure. High volume ISB and also, to a lesser extent, low volume ISB were found to be responsible for diaphragmatic paralysis. TRIAL REGISTRY NUMBER: Registration n° 2014-202.

Inside anesthesia breathing circuits: time to reach a set sevoflurane concentration in toddlers and newborns: simulation using a test lung.

We measured the time it takes to reach the desired inspired anesthetic concentration using the Primus (Drägerwerk, AG, Lübeck, Germany) and the Avance (GE Datex-Ohmeda, Munich, Germany) anesthesia machines with toddler and newborn ventilation settings. The time to reach 95% of inspired target sevoflurane concentration was measured during wash-in from 0 to 6 vol% sevoflurane and during wash-out from 6 to 0 vol% with fresh gas flows equal to 1 and 2 times the minute ventilation. The Avance was faster than the Primus (65 seconds [95% confidence interval (CI): 55 to 78] vs 310 seconds [95% CI: 261 to 359]) at 1.5 L/min fresh gas flow, tidal volume of 50 mL, and 30 breaths/min. Times were shorter by the same magnitude at higher fresh gas flows and higher minute ventilation rates. The effect of doubling fresh gas flow was variable and less than expected. The Primus is slower during newborn than toddler ventilation, whereas the Avance's response time was the same for newborn and toddler ventilation. Our data confirm that the time to reach the target-inspired anesthetic concentration depends on breathing circuit volume, fresh gas flow, and minute ventilation.

Total knee arthroplasty under quadruple nerve block with ropivacaine 0.32%: effect of addition of intravenous dexmedetomidine to intravenous dexamethasone on analgesic duration.

BACKGROUND AND OBJECTIVES: Peripheral nerve blocks reduce postoperative pain and enhance recovery after total knee arthroplasty (TKA). This study aims to assess the benefits of addition of intravenous dexmedetomidine (DexM) to intravenous dexamethasone on the analgesic duration of quadruple nerve blocks. METHODS: This double-blind, randomized, controlled trial prospectively enrolled 90 patients scheduled for TKA under quadruple nerve blocks (sciatic, femoral, obturator, and lateral femoral cutaneous nerves blocks) with 70 mL, 0.32% ropivacaine. All patients received systemic dexamethasone 10 mg. Patients were randomized to receive DexM (2 µg/kg, intravenous) or placebo (1:1 ratio). The primary endpoint was the duration of analgesia defined as the time to first request for rescue analgesia (oxycodone). RESULTS: Kaplan-Meier curves for the first analgesic request were similar between groups (log-rank test; p=0.27). Median (IQR) duration of analgesia was similar between placebo (1575 min (1211-1952)) and DexM (1470 min (1263-1700)) groups (p=0.56). Cumulative consumption of oxycodone at the 48th hour was 20 mg (10-30) and 30 mg (20-40) in placebo and DexM groups, respectively (p=0.14). The day after surgery, 93% and 89% of patients were able to walk in placebo and DexM groups, respectively (p=0.46). Intravenous DexM was associated with bradycardia, hypotension and longer recovery room stay (p<0.05 for all comparisons). CONCLUSIONS: In a multimodal analgesic regimen, addition of systemic DexM (2 µg/kg) to systemic dexamethasone does not prolong the analgesic duration of quadruple nerve block with ropivacaine 0.32% after TKA. TRIAL REGISTRATION NUMBER: NCT03834129.

Obturator nerve block does not provide analgesic benefits in total hip arthroplasty under multimodal analgesic regimen: a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Although regional analgesia is considered an important component of optimal pain management, use of peripheral nerve blocks for total hip arthroplasty remains controversial. Since the obturator nerve innervates the anteromedial part of the joint capsule, we hypothesized that an obturator nerve block would decrease the opioid consumption after total hip arthroplasty. METHODS: In this single center, prospective, triple blinded study, we randomly allocated 60 patients undergoing total hip arthroplasty under opioid-sparing total intravenous general anesthesia to a preoperative obturator nerve block or a sham block (placebo group) using 20 mL of ropivacaine 0.2% or saline, respectively. All patients received a multimodal analgesic regimen with non-opioid analgesics including periarticular local infiltration analgesia. The primary outcome was the intravenous opioid consumption in the post-anesthesia care unit. RESULTS: Median (IQR) intravenous oxycodone consumption in the post-anesthesia care unit was 4 (2, 7.5) mg in the obturator nerve block group and 3 (0, 4) mg in the placebo group (p=0.05). There were no differences in pain scores between groups in the first 24 hours except at arrival on the surgical ward with significant higher pain scores in the placebo group (p=0.03). The ability to stand up and walk within 24 hours was comparable between groups as was the time to first walk (180 (90, 720) vs 240 (120, 780) min for the obturator nerve block and placebo groups, respectively; p=0.62). CONCLUSIONS: Obturator nerve block did not improve postoperative opioid consumption after total hip arthroplasty performed under general anesthesia with a multimodal analgesic regimen. TRIAL REGISTRATION NUMBER: NCT04085640.

Perineural Versus Systemic Dexamethasone in Front-Foot Surgery Under Ankle Block: A Randomized Double-Blind Study.

BACKGROUND AND OBJECTIVES: Among the different adjuvants, dexamethasone is one of the most accepted to prolong the effect of local anesthetics. This study aims to determine the superiority of perineural over systemic dexamethasone administration after a single-shot ankle block in metatarsal osteotomy. METHODS: We performed a prospective, double-blind, randomized study. A total of 100 patients presenting for metatarsal osteotomy with an ankle block were randomized into 2 groups: 30 mL ropivacaine 0.375% + perineural dexamethasone 4 mg (1 mL) + 2.5 mL of systemic saline solution (PNDex group, n = 50) and 30 mL ropivacaine 0.375% + 1 mL of perineural saline solution + intravenous dexamethasone 10 mg (2.5 mL) (IVDex group, n = 50). The primary end point was the duration of analgesia defined as the time between the performance of the ankle block and the first administration of rescue analgesia with tramadol. RESULTS: Time period to first rescue analgesia with tramadol was similar in the IVDex group and the PNDex group. Data are expressed as mean (SD) or median (range). Duration of analgesia was 23.2 (9.5) hours in the IVDex group and 19 (8.2) hours in the PNDex group (P = 0.4). Consumption of tramadol during the first 48 hours was 0 mg (0-150 mg) in the IVDex group versus 0 mg (0-250 mg) in the PNDex group (P = 0.59). Four (8%) and 12 (24%) patients reported nausea or vomiting in the IVDex group and the PNDex group, respectively (P = 0.03). CONCLUSIONS: In front-foot surgery, perineural and systemic administrations of dexamethasone are equivalent for postoperative pain relief when used as an adjuvant to ropivacaine ankle block. CLINICAL TRIAL REGISTRATION: This study was registered at ClinicalTrials.gov, identifier NCT02904538.

Fortuitous Diagnosis of Preexisting Neuropathy During Ultrasound-Guided Regional Anesthesia Performance: A Case Report.

Ultrasound-guided regional anesthesia requires the anesthesia provider to interpret new information. This article reports on the case of a 38-year-old man scheduled for a fifth metacarpal fracture repair. Ultrasound nerve examination revealed abnormal pathology of the axillary brachial plexus consisting of an increased volume of the terminal nerves of the brachial plexus. Ultrasound scanning initiated the subsequent diagnosis of multifocal motor neuropathy. Regional anesthesia was abandoned in favor of general anesthesia. Ultrasonography training needs to be expanded in the coming years to include awareness of the abnormal pathology, as it might impact the choice of anesthetic procedure and patient outcome.