Continuous erector spinae plane block versus intercostal nerve block in patients undergoing video-assisted thoracoscopic surgery: a pilot randomized controlled trial.

BACKGROUND: The optimal analgesia method in video-assisted thoracoscopic surgery (VATS) remains controversial. Intercostal nerve blockade (ICNB) is limited by its duration of action. The erector spinae plane (ESP) block has the potential to provide satisfactory analgesia for VATS; however, the effectiveness of continuous ESP versus surgeon-performed ICNB has not been investigated. The objectives of this study were to establish feasibility of patient recruitment and follow-up before undertaking a fully powered randomized controlled trial (RCT); and, secondarily, to compare opioid usage, pain control, and sensory blockade. METHODS: This feasibility RCT was undertaken at St Joseph's Hospital, Hamilton, Ontario, Canada, and included 24 patients (>18 years) having elective VATS with at least one overnight stay. Exclusion criteria were patient refusal, body mass index >40 kg/m2, contraindications to neuraxial analgesia techniques as per the American Society of Regional Anesthesia and Pain guidelines, known allergy to local anesthetics, language or comprehension barriers, procedures with a higher chance of open surgery, and regular opioid use for ≥3 months preoperatively. Patients underwent either continuous ESP (n=12) or surgeon-performed ICNB (n=12). All patients received routine intraoperative anesthesia care and multimodal analgesia. Feasibility criteria were recruitment rate of two patients/week and full follow-up in all patients in-hospital. We compared opioid consumption, postoperative pain scores (0-10 numerical rating scale), adverse events, patient satisfaction, and distribution of sensory blockade as clinical outcomes (secondary). RESULTS: Feasibility of primary outcomes was successfully demonstrated. Five patients had an epidural in anticipation of open surgery. Mean opioid consumption as equivalent morphine units was less in the ESP group over the first 24 h (mean difference, 1.63 [95% CI -1.20 to 4.45]) and 48 h (mean difference, 2.34 [95% CI -1.93 to 6.61]). There were no differences in adverse effects. CONCLUSIONS: A fully powered RCT is feasible with modifications. Our results also suggest that continuous ESP is safe and can decrease opioid needs. However, it is important to consider procedures to improve compliance to protocol and adherence to assigned interventions. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03176667 . Registered June 5, 2017.

Randomized control trial of ultrasound-guided erector spinae block versus shoulder periarticular anesthetic infiltration for pain control after arthroscopic shoulder surgery: Study protocol clinical trial (SPIRIT compliant).

INTRODUCTION: Moderate to severe postoperative pain and associated opioid use may interfere with patients' well-being and course of recovery. Regional anesthetic techniques provide an opportunity for opioid sparing and improved patient outcomes. A new regional technique called the erector spinae plane (ESP) block has the potential to provide effective analgesia after shoulder arthroscopy with minimal risks and decreased opioid consumption. Our primary objective is to determine whether, in patients who undergo arthroscopic shoulder surgery, a preoperative ESP block reduces pain scores as compared to periarticular infiltration at the end of surgery. Additionally, we will also examine other factors such as opioid consumption, sensory block, adverse events, patient satisfaction, and persistent pain. METHODS: This is a 2-arm, single-center, parallel-design, double-blind randomized controlled trial of 60 patients undergoing arthroscopic shoulder surgery. Eligible patients will be recruited in the preoperative clinic. Using a computer-generated randomization, with a 1:1 allocation ratio, patients will be randomized to either the ESP or periarticular infiltration group. Patients will be followed in hospital in the postanesthesia care unit, at 24 hours, and at 1 month. The study with be analyzed as intention-to-treat. DISCUSSION: This study will inform an evidence-based choice in recommending ESP block for shoulder arthroscopy, as well as providing safety data. The merits of the study include its double dummy blinding to minimize observer bias, and its assessment of patient important outcomes, including pain scores, opioid consumption, and patient satisfaction. This study will also help provide an estimate of the incidence of side effects and complications of the ESP block. TRIAL REGISTRATION NUMBER: NCT03691922; Recruited Date of registration: October 2, 2018.

N-Methyl-D-Aspartate Antagonists and Steroids for the Prevention of Persisting Post-Surgical Pain After Thoracoscopic Surgeries: A Randomized Controlled, Factorial Design, International, Multicenter Pilot Trial.

PURPOSE: We conducted a feasibility 2×2 factorial trial comparing N-methyl-D-aspartate (NMDA) antagonists (intravenous ketamine and oral memantine) versus placebo and intravenous steroids versus placebo, in patients having elective video-assisted thoracic surgery lobectomies, at St. Joseph's Hamilton, Canada, and Cleveland Clinic, Cleveland, USA. Our feasibility objectives were: 1) recruitment rate/week; 2) recruitment of ≥90% of eligible patients; and 3) >90% follow-up. Secondary objectives were incidence and intensity of persistent post-surgical pain (PPSP) and other clinical and safety outcomes. METHODS: Using computerized randomization, patients were allocated to one of four groups: NMDA active with steroid placebo; NMDA placebo with steroid active; both NMDA and steroid active; both NMDA and steroid placebo. Patients, health providers, and data analysts were blinded to allocation. Patients were followed for 3 months after randomization. RESULTS: The trial was initiated in May 2017 at Hamilton and, after subsequent regulatory and ethics approval, in April 2018 at Cleveland. The trial had to be stopped after only 1 month of recruitment in Cleveland because the packaged study medications (memantine) expired and we were unable to procure the dosage required. Among 41 eligible patients, 27 (66%) were randomized. The recruitment rate/week was 0.63, 95% confidence interval (CI): 0.47-0.79 in Hamilton; and 1, 95% CI: 0.83-1.17 in Cleveland. Follow-up was complete for all 24 patients (100%) in Hamilton, and 3 of 4 patients in Cleveland. In total, only 4 patients (15%), and 2 patients (7%) had persistent pain at rest and with movement, respectively. There were no significant differences between groups for other outcomes. CONCLUSION: The trial had to be stopped prematurely due to non-availability of study medications. Trial feasibility objectives of recruiting 90% of eligible patients and recruiting at least one patient/week per site were not met. Consideration for protocol changes will be necessary for the full trial. TRIAL REGISTRATION: NCT02950233.

Use of lung-protective strategies during one-lung ventilation surgery: a multi-institutional survey.

BACKGROUND: Limited evidence suggests that intraoperative lung-protective ventilation (LPV) during one-lung ventilation (OLV) may reduce respiratory complications after thoracic surgery. Little is known about LPV practices during OLV. Our purpose was to assess the state of practice/perspectives of anesthesiologists regarding LPV during elective OLV. METHODS: We conducted a multi-institutional cross-sectional survey of anesthesiologists performing OLV at high-volume Canadian tertiary/university centers. The survey was designed, refined and distributed by a multi-disciplinary team using the Dillman method. Univariable and multivariable analyses were used. RESULTS: Seventy-five (63%) of 120 eligible respondents completed the survey. Although the critical care literature focuses on minimizing tidal volume (TV) as the central strategy of LPV, most respondents (89%, n=50/56) focused on minimizing peak airway pressure (PAP) as their primary strategy of intraoperative LPV. Only 64% (n=37/58) reported actively trying to minimize TV. While 32% (n=17/54) were unsure about the current evidence regarding LPV, 67% (n=36/54) believed that the evidence favoured their use during OLV. Perceived clinical and institutional barriers were the only predictors of reduced attempts to minimize TV on univariate analyses. In multivariable/adjusted analyses, perceived institutional barriers were the only predictors of reduced attempts to minimize TV with adjusted odds ratio of 0.1 (95% CI: 0.03-0.6). CONCLUSIONS: Most anesthesiologists defined low PAP as the primary strategy of LPV during OLV and attempted to minimize it. This study is the first to assess the practice/perspectives of anesthesiologists regarding LPV during OLV and also the first to explore predictors of LPV use. Randomized trials are currently ongoing. However, this study suggests that institutional barriers may subvert future knowledge translation and need to be addressed.

Survey of Postoperative Regional Analgesia for Thoracoscopic Surgeries in Canada.

OBJECTIVES: To determine the preferences and perceptions regarding analgesic options for video-assisted thoracic surgery (VATS) among thoracic anesthesiologists in Canada. DESIGN: A cross-sectional survey of thoracic anesthesiologists with 30 multiple choice questions was e-mailed through an online survey tool called FluidSurveys was performed to members of the Canadian Anesthesiologists' Society. SETTING: A nationwide survey. PARTICIPANTS: Members of Canadian Anesthesiologists' Society who provide thoracic anesthesia INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Participant characteristics and outcomes are described using counts and percentages. The frequency of use of each technique for each surgical category is described in percentages and 95% confidence intervals. Based on the responses obtained from individual centers, approximately 469 anesthesiologists provided thoracic care in Canada at the time of the survey. The response rate to the survey was 19% (n = 89). Epidural analgesia was preferred by 93.42% (95% CI 85-98) for open surgeries compared with 41% (30-52) for VATS lobectomies. The difference was statistically significant-52% (37-67). Patient-controlled analgesia was preferred by 27% (19-39) for VATS lobectomies and 46% (35-57) for VATS minor resections. Only 14% preferred paravertebral block for any VATS surgeries. CONCLUSIONS: The use of analgesic techniques for VATS surgeries is variable and largely dictated by provider preferences. The majority still prefer epidural analgesia compared with paravertebral catheter (placed either by the anesthesiologist or surgeon). A broadly acceptable choice that is effective, safe, and technically less demanding requires comparative effectiveness studies and more uniform training for physicians.

Optimizing Pain and Rehabilitation After Knee Arthroplasty: A Two-Center, Randomized Trial.

BACKGROUND: This randomized trial compared (1) continuous femoral nerve block (cFNB), (2) single femoral nerve block (sFNB), and (3) local infiltration analgesia (LIA) with respect to analgesic and functional outcomes after primary tricompartmental knee arthroplasty (TKA). METHODS: One hundred twenty patients undergoing primary tricompartmental knee arthroplasty were randomly assigned to 1 of 3 interventions for postoperative analgesia: (1) cFNB-preoperative bolus of ropivacaine 0.5% 20 mL followed by ropivacaine 0.2% 5 mL per hour for 48 hours; (2) sFNB-preoperative bolus of ropivacaine 0.5% 20 mL with placebo 0.9% saline 5 mL per hour for 48 hours; or (3) LIA-intraoperative tricompartmental injection of ropivacaine 0.2% (150 mL) with epinephrine (10 µg/mL) and ketorolac 30 mg with femoral placebo 0.9% saline 20 mL preoperative bolus and 0.9% saline placebo 5 mL per hour for 48 hours. All participants received an identical, standardized, postoperative multimodal analgesic regimen. Participants, health care providers, data collectors, and analysts were blinded. All participants received identical perineural catheters and perineural/LIA solution (depending on randomized intervention) to maintain blinding. The primary outcome measure was numeric rating scale for pain (NRS) during physiotherapy on postoperative day (POD) 2 at 9:00 AM. Secondary outcomes included opioid consumption, NRS on POD 1 (rest/physiotherapy/worst), functional outcomes, and block complications. RESULTS: For the primary outcome, pain during physiotherapy on POD 2 at 9:00 AM, the overall analysis of covariance (ANCOVA) was significant (P = .049), but pairwise comparisons did not demonstrate any significant differences between treatment arms. NRS was 4.6 (95% confidence interval [CI], 3.3-6.0) for the cFNB group, 4.6 (95% CI, 3.3-6.0) for the sFNB group, and 3.4 (95% CI, 2.2-4.8) for the LIA group. The following is the mean difference in NRS on POD 2 at 9:00 AM among groups: cFNB-LIA (1.2, 95% CI, -0.1 to 2.5; P = .073); sFNB-LIA (1.2, 95% CI, -0.2 to 2.5; P = .097); cFNB-sFNB (0.0, 95% CI, -1.3 to 1.4; P = .996). There were no statistically significant differences between groups in cumulative 48-hour opioid consumption or functional outcomes. cFNB and LIA were superior to sFNB for NRS on POD 1 for worst pain experienced and pain during physiotherapy, respectively. There were no adverse events associated with study procedures reported among participants in the 3 groups. CONCLUSIONS: Our findings suggest no clinically significant differences between cFNB, LIA, and sFNB for pain during physiotherapy on POD 2 after TKA. Secondary analyses suggest that cFNB and LIA are superior to sFNB for early analgesic outcomes (NRS on POD 1) after TKA.

Chronic intermittent asphyxia impairs rat upper airway muscle responses to acute hypoxia and asphyxia.

BACKGROUND: Obstructive sleep apnea (OSA) is a major clinical disorder that is characterized by multiple episodes of upper airway obstruction due to the failure of the upper airway dilator muscles to maintain upper airway patency. This results in chronic intermittent asphyxia (CIA) due to repetitive apneas, but very little is known about the effects of CIA on upper airway muscle function. OBJECTIVE: To test the hypothesis that CIA affects upper airway muscle activity and electromyogram (EMG) responses to acute hypoxia and asphyxia. DESIGN: Record upper airway EMG responses to acute hypoxia and asphyxia in control and CIA-treated rats. SETTING: Department of Physiology, Royal College of Surgeons in Ireland, Dublin, Ireland. MEASUREMENTS: Sternohyoid (SH) muscle and diaphragm (DIA) muscle EMG activities were recorded in both groups during normoxia, hypoxia (7.5% O(2) in N(2)), and asphyxia (7.5% O(2) and 3% CO(2)) under pentobarbitone anesthesia. RESULTS: Baseline SH EMG activity was significantly elevated in the CIA-treated rats compared to the controls, whereas DIA EMG activity was similar in the two groups. In addition, CIA significantly reduced SH EMG but not DIA EMG responses to acute hypoxia and asphyxia. CONCLUSIONS: The elevated upper airway muscle activity associated with OSA in humans during wakefulness is due at least in part to CIA. We propose that a reduction in the response of upper airway dilator muscles to acute asphyxia following upper airway obstruction is likely to cause further asphyxic insult, leading to a vicious feed-forward cycle exacerbating the condition. Our results suggest that CIA contributes to the pathophysiology of sleep-disordered breathing.