Adductor canal block with or without added magnesium sulfate following total knee arthroplasty: a multi-arm randomized controlled trial.

PURPOSE: Postoperative analgesia following total knee arthroplasty (TKA) often includes intrathecal opioids, periarticular injection (PAI) of local anesthetic, systemic multimodal analgesia, and/or peripheral nerve blockade. The adductor canal block (ACB) provides analgesia without muscle weakness and magnesium sulphate (MgSO4) may extend its duration. The purpose of this trial was to compare the duration and quality of early post-TKA analgesia in patients receiving postoperative ACB (± MgSO4) in addition to standard care. METHODS: Elective TKA patients were randomized to: 1) sham ACB, 2) ropivacaine ACB, or 3) ropivacaine ACB with added MgSO4. All received spinal anesthesia with intrathecal morphine, intraoperative PAI, and multimodal systemic analgesia. Patients and assessors remained blinded to allocation. Anesthesiologists knew whether patients had received sham or ACB but were blinded to MgSO4. The primary outcome was time to first analgesic (via patient-controlled analgesia [PCA] with iv morphine) following ACB. Secondary outcomes were morphine consumption, side effects, visual analogue scale pain scores, satisfaction until 24 hr postoperatively, and length of stay. RESULTS: Of 130 patients, 121 were included. Nine were excluded post randomization: four were protocol violations, three did not meet inclusion criteria, and two had severe pain requiring open label blockade. There were no differences in the median [interquartile range] time to first PCA request: sham, 310 min [165-550]; ropivacaine ACB, 298 min [120-776]; and ropivacaine ACB with MgSO4, 270 min [113-780] (P = 0.96). Similarly, we detected no differences in resting pain, opioid consumption, length of stay, or associated side effects until 24 hr postoperatively. CONCLUSION: We found no analgesic benefit of a postoperative ACB, with or without added MgSO4, in TKA patients undergoing spinal anesthesia and receiving intrathecal morphine, an intraoperative PAI, and multimodal systemic analgesia. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02581683); registered 21 October 2015.

RéSUMé: OBJECTIF: L'analgésie postopératoire suivant une arthroplastie totale du genou (ATG) inclut souvent des opioïdes intrathécaux, une injection périarticulaire (IPA) d'anesthésique local, une analgésie multimodale systémique, et/ou des blocs des nerfs périphériques. Le bloc du canal des adducteurs (BCA) permet une analgésie sans faiblesse musculaire et le sulfate de magnésium (MgSO4) pourrait prolonger sa durée. L'objectif de cette étude était de comparer la durée et la qualité de l'analgésie post-ATG précoce chez les patients recevant un BCA postopératoire (± MgSO4) en plus des soins standard. MéTHODE: Des patients devant subir une ATG non urgente ont été randomisés à recevoir : 1) un BCA placebo (groupe témoin), 2) un BCA avec ropivacaïne, ou 3) un BCA avec ropivacaïne et MgSO4. Tous ont reçu une rachianesthésie avec morphine intrathécale, une IPA peropératoire, et une analgésie multimodale systémique. L'allocation a été faite à l'insu des patients et des évaluateurs. Les anesthésiologistes savaient si les patients avaient reçu un placebo ou un BCA, mais n'étaient pas informés de l'ajout ou non de MgSO4. Le critère d'évaluation principal était le temps jusqu'à la première prise d'analgésique (via une analgésie contrôlée par le patient [ACP] avec de la morphine iv) après le BCA. Les critères secondaires comprenaient la consommation de morphine, les effets secondaires, les scores de douleur sur l'échelle visuelle analogue, la satisfaction jusqu'à 24 heures postopératoires, et la durée de séjour. RéSULTATS: Sur 130 patients, 121 ont été inclus. Neuf ont été exclus après la randomisation : quatre l'ont été en raison de violations du protocole, trois ne répondaient pas aux critères d'inclusion, et deux ont ressenti des douleurs graves nécessitant un bloc sans insu. Aucune différence n'a été observée dans le temps médian [écart interquartile] jusqu'à la première demande d'ACP : placebo, 310 min [165-550]; BCA ropivacaïne, 298 min [120-776]; et BCA ropivacaïne avec MgSO4, 270 min [113-780] (P = 0,96). De la même manière, nous n'avons détecté aucune différence dans la douleur au repos, la consommation d'opioïdes, la durée de séjour, ou les effets secondaires associés jusqu'à 24 heures postopératoires. CONCLUSION: Nous n'avons trouvé aucun avantage analgésique à un BCA postopératoire, avec ou sans ajout de MgSO4, chez les patients subissant une ATG sous rachianesthésie et recevant de la morphine intrathécale, une IPA peropératoire, et une analgésie multimodale systémique. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT02581683); enregistrée le 21 octobre 2015.

A survey of anesthetic preference and preoperative anxiety in hip and knee arthroplasty patients: the utility of the outpatient preoperative anesthesia appointment.

PURPOSE: The general public's perceptions of anesthesia and the risks associated with it may be skewed. The outpatient preoperative appointment with an anesthesiologist allows for patient education regarding different anesthetic options and counseling regarding anxiety related to anesthesia and surgery. This study investigates whether the preoperative appointment for hip and knee arthroplasty alters patient preference for general or spinal anesthesia and reduces patient anxiety. METHODS: Sixty-two patients undergoing hip or knee arthroplasty were administered two verbal questionnaires at the preoperative clinic. The first questionnaire was completed prior to meeting the anesthesiologist and addressed patient anesthetic preferences, previous anesthetic experiences, and perioperative anxiety and need for information using the Amsterdam Preoperative Anxiety and Information Scale (APAIS). The second questionnaire was completed immediately following the appointment and addressed the patient's anesthetic preference, reasons for any preference changes, and anxiety levels and need for information using the APAIS. The clinic anesthesiologist was blinded to the nature of the study. RESULTS: Following the clinic appointment, a significant decrease in patients wanting general anesthesia (from 48 to 18%, P < 0.001) and a significant increase in patients wanting spinal anesthesia (from 39 to 76%, 95%, P < 0.01) was noted. A significant decrease in overall anxiety and anxiety related to the patients' upcoming surgeries and need for information was also noted. CONCLUSIONS: The preoperative anesthesia meeting serves an important role in educating patients regarding anesthesia, and can influence patients' choice of anesthetic while also reducing overall patient anxiety.

Bias in Before-After Studies: Narrative Overview for Anesthesiologists.

Before-after study designs are effective research tools and in some cases, have changed practice. These designs, however, are inherently susceptible to bias (ie, systematic errors) that are sometimes subtle but can invalidate their conclusions. This overview provides examples of before-after studies relevant to anesthesiologists to illustrate potential sources of bias, including selection/assignment, history, regression to the mean, test-retest, maturation, observer, retrospective, Hawthorne, instrumentation, attrition, and reporting/publication bias. Mitigating strategies include using a control group, blinding, matching before and after cohorts, minimizing the time lag between cohorts, using prospective data collection with consistent measuring/reporting criteria, time series data collection, and/or alternative study designs, when possible. Improved reporting with enforcement of the Enhancing Quality and Transparency of Health Research (EQUATOR) checklists will serve to increase transparency and aid in interpretation. By highlighting the potential types of bias and strategies to improve transparency and mitigate flaws, this overview aims to better equip anesthesiologists in designing and/or critically appraising before-after studies.

Pre- or postoperative interscalene block and/or general anesthesia for arthroscopic shoulder surgery: a retrospective observational study.

PURPOSE: Arthroscopic shoulder surgery can be performed with an interscalene brachial plexus block (ISBPB) alone, ISBPB combined with general anesthesia (GA), or GA alone. Postoperative pain is typically managed with opioids; however, both GA and opioids have adverse effects which can delay discharge. This retrospective study compares the efficacy of four methods of anesthesia management for arthroscopic shoulder surgery. METHODS: Charts of all patients who underwent shoulder surgery by a single surgeon from 2012-2015 were categorized by analgesic regimen: GA only (n = 177), single-shot ISBPB only (n = 124), or pre- vs postoperative ISBPB combined with GA (ISBPB + GA [n = 72] vs GA + ISBPB [n = 52], respectively). The primary outcome measure was the time to discharge from the postanesthesia care unit (PACU). RESULTS: Mean (SD) time in the PACU ranged from 70.5 (39.9) min for ISBPB only to 111.2 (56.9) min for GA only. Use of ISBPB in any combination and regardless of timing resulted in significantly reduced PACU time, with a mean drop of 27.2 min (95% confidence interval [CI], 17.3 to 37.2; P < 0.001). The largest mean pairwise difference was between GA only and ISBPB only, with a mean difference of 40.7 min (95% CI, 25.5 to 55.8; P < 0.001). Use of ISBPB also reduced pain upon arrival at the PACU and, in some cases, upon discharge from the PACU (i.e., ISBPB only but not ISBPB + GA compared with GA). An ISBPB (alone or prior to GA) also reduced analgesic requirements. CONCLUSION: Previously reported benefits of an ISBPB for arthroscopic shoulder surgery are confirmed. Postoperative ISBPBs may also be beneficial for reducing pain and opioid requirements and could be targeted for patients in severe pain upon emergence. A sufficiently powered randomized-controlled trial could determine the relative efficacy, safety, and associated financial implications associated with each method.