Paravertebral versus Pectoralis-II (Interpectoral and Pectoserratus) Nerve Blocks for Postoperative Analgesia after Non-Mastectomy Breast Surgery: A Randomized, Controlled, Observer-Masked Noninferiority Trial.

BACKGROUND: Pectoralis-II and paravertebral nerve blocks are both used to treat pain following breast surgery. Most previous studies involving mastectomy identified little difference of significance between the two approaches. Whether this is also accurate for non-mastectomy procedures remains unknown. METHODS: Participants undergoing uni- or bilateral non-mastectomy breast surgery anticipated to have at least moderate postoperative pain were randomized to a pectoralis-II or paravertebral block (90 mg ropivacaine/side for both). Surgeons and recovery room staff were masked to treatment group assignment, and participants were not informed of their treatment group. Injectate for pectoralis-II blocks was ropivacaine 0.3% (30 mL) per side. Injectate for paravertebral blocks was ropivacaine 0.5% (9 mL in each of 2 levels) per side. We hypothesized that pectoralis-II blocks would have noninferior (1) analgesia [Numeric Rating Scale] and (2) cumulative opioid consumption within the operating and recovery rooms combined (dual primary outcomes). The study was adequately powered with n=100, but the target enrollment was raised to n=150 to account for higher-than-anticipated variability. RESULTS: The trial was ended prematurely with 119 (79%) of the original target of 150 participants enrolled due to (masked) surgeon preference. Within the recovery room, pain scores were higher in participants with pectoralis-II (n=60) than paravertebral blocks (n=59): median [IQR] 3.3 [2.3, 4.8] vs 1.3 [0, 3.6]; 95% CI: 0.5 to 2.6; P < 0.001. Similarly, intravenous morphine equivalents were higher in the pectoralis-II group: 17.5 [12.5, 21.9] vs 10.0 mg [10, 20]; 95% CI: 0.1 to 7.5; P = 0.004. No block-related adverse events were identified in either group. CONCLUSIONS: Following non-mastectomy breast surgery, 2-level paravertebral blocks provided superior analgesia and opioid sparing compared with pectoralis-II blocks. This is a contrary finding to the majority of studies in patients having mastectomy in which little significant difference was identified between the two types of blocks.

Robot-assisted laparoscopic nephrectomy: early outcome measures with the implementation of multimodal analgesia and intrathecal morphine via the acute pain service.

PURPOSE: The objective of this study was to perform a retrospective cohort analysis, in which we measured the association of an acute pain service (APS)-driven multimodal analgesia protocol that included preoperative intrathecal morphine (ITM) compared to historic controls (i.e., surgeon-driven analgesia protocol without ITM) with postoperative opioid use. METHODS: This was a retrospective cohort study in which the primary objective was to determine whether there was a decrease in median 24-h opioid consumption (intravenous morphine equivalents [MEQ]) among robotic nephrectomy patients whose pain was managed by the surgical team prior to the APS, versus pain managed by APS. Secondary outcomes included opioid consumption during the 24-48 h and 48-72 h period and hospital length of stay. To create matched cohorts, we performed 1:1 (APS:non-APS) propensity score matching. Due to the cohorts occurring at the different time periods, we performed a segmented regression analysis of an interrupted time series. RESULTS: There were 76 patients in the propensity-matched cohorts, in which 38 (50.0%) were in the APS cohort. The median difference in 24-h opioid consumption in the pre-APS versus APS cohort was 23.0 mg [95% CI 15.0, 31.0] (p < 0.0001), in favor of APS. There were no differences in the secondary outcomes. On segmented regression, there was a statistically significant drop in 24-h opioid consumption in the APS cohort versus pre-APS cohort (p = 0.005). CONCLUSIONS: The implementation of an APS-driven multimodal analgesia protocol with ITM demonstrated a beneficial association with postoperative 24-h opioid consumption following robot-assisted nephrectomy.

Intrathecal Morphine Injection for Postoperative Analgesia Following Gender-Affirming Pelvic Surgery: A Retrospective Case-Control Study.

Background Gender-affirming pelvic surgery (GAPS) can be associated with significant postoperative pelvic pain. Given the lack of available peripheral nerve blocks to the perineum, intrathecal morphine (ITM) injection could offer a potent analgesic modality for this patient population. No prior studies to date have been performed examining the analgesic effects of intrathecal morphine for these patients. Methods This retrospective case-control study aims to understand the postoperative analgesic effects of intrathecal morphine for these patients with a historical comparison group of patients who did not receive intrathecal morphine. Results Fourteen patients presented for gender-affirming pelvic surgery over an eight-month period at a single institution and were offered intrathecal morphine for postoperative analgesia. Their analgesic results were compared to a similar historical group of 13 patients who were not offered or declined intrathecal morphine. Conclusions Intrathecal morphine injection is a potent analgesic modality for patients presenting for gender-affirming pelvic surgery.

Relative Effects of Various Factors on Ice Ball Formation and Ablation Zone Size During Ultrasound-Guided Percutaneous Cryoneurolysis: A Laboratory Investigation to Inform Clinical Practice and Future Research.

INTRODUCTION: Ultrasound-guided percutaneous cryoneurolysis provides analgesia using cold temperatures to reversibly ablate peripheral nerves. Cryoneurolysis probes pass a gas through a small internal annulus, rapidly lowering the pressure and temperature, forming an ice ball to envelope the target nerve. Analgesia is compromised if a nerve is inadequately frozen, and laboratory studies suggest that pain may be paradoxically induced with a magnitude and duration in proportion with the incomplete ablation. We therefore investigated the relative effects of various factors that may contribute to the size of the ice ball and the effective cryoneurolysis zone. METHODS: A cryoprobe was inserted into a piece of meat, a gas was passed through for 2 min, and the resulting ice ball width (cross-section) and length (axis parallel to the probe) were measured using ultrasound, with the temperature evaluated in nine concentric locations concurrently. RESULTS: The factor with the greatest influence on ice ball size was probe gauge: in all probe types, a change from 18 to 14 increased ice ball width, length, and volume by up to 70%, 113%, and 512% respectively, with minimum internal temperature decreasing as much as from -5 to -32 °C. In contrast, alternating the type of meat (chicken, beef, pork) and the shape of the probe tip (straight, coudé) affected ice ball dimensions to a negligible degree. The ice ball dimensions and the zone of adequate temperature drop were not always correlated, and, even within a visualized ice ball, the temperature was often inadequate to induce Wallerian degeneration. CONCLUSIONS: Percutaneous probe design can significantly influence the effective cryoneurolysis zone; visualizing a nerve fully encompassed in an ice ball does not guarantee adequate treatment to induce the desired Wallerian degeneration because ice forms at temperatures between 0 and -20 °C, whereas only temperatures below -20 °C induce Wallerian degeneration. The correlation between temperatures in isolated pieces of meat and perfused human tissue remains unknown, and further research to evaluate these findings in situ appears highly warranted.

Wearable, noninvasive, pulsed shortwave (radiofrequency) therapy for analgesia and opioid sparing following outpatient surgery: A proof-of-concept case series.

BACKGROUND: It is often difficult to concurrently provide adequate analgesia while minimizing opioid requirements following ambulatory surgery. Nonthermal, pulsed shortwave (radiofrequency) fields are a noninvasive treatment used as an adjunct analgesic and wound healing therapy. The devices may be placed by nursing staff in less than a minute, are relatively inexpensive and readily available, theoretically provide analgesia for nearly any anatomic location, and have no systemic side effects-patients cannot detect any sensations from the devices-or significant risks. Here we present a case series to demonstrate the use of pulsed, electromagnetic field devices for outpatient herniorrhaphy and breast surgery. CASE REPORT: Following moderately painful ambulatory umbilical (n = 3) and inguinal (n = 2) hernia repair as well as bilateral breast surgery (n = 2), patients had taped over their surgical incision(s) 1 or 2 noninvasive, wearable, disposable, pulsed shortwave therapy devices (RecoveryRx, BioElectronics Corporation, Frederick, Maryland) which functioned continuously for 30 days. Average resting pain scores measured on the 0-10 numeric rating scale were a median of 0 during the entire treatment period. Six patients avoided opioid use entirely, while the remaining individual required only 5 mg of oxycodone during the first postoperative day. CONCLUSIONS: These cases demonstrate that the ambulatory use of pulsed shortwave devices is feasible and may be an effective analgesic, possibly obviating opioid requirements following outpatient herniorrhaphy and breast surgery. Considering the lack of any side effects, adverse events, and misuse/dependence/diversion potential, further study with a randomized, controlled trial appears warranted.

Preoperative Ultrasound-guided Percutaneous Cryoneurolysis for the Treatment of Pain after Mastectomy: A Randomized, Participant- and Observer-masked, Sham-controlled Study.

BACKGROUND: Ultrasound-guided percutaneous cryoneurolysis is an analgesic technique in which a percutaneous probe is used to reversibly ablate a peripheral nerve(s) using exceptionally low temperature, and has yet to be evaluated with randomized, controlled trials. Pain after mastectomy can be difficult to treat, and the authors hypothesized that the severity of surgically related pain would be lower on postoperative day 2 with the addition of cryoanalgesia compared with patients receiving solely standard-of-care treatment. METHODS: Preoperatively, participants at one enrolling center received a single injection of ropivacaine, 0.5%, paravertebral nerve block at T3 or T4, and perineural catheter. Participants subsequently underwent an active or sham ultrasound-guided percutaneous cryoneurolysis procedure of the ipsilateral T2 to T5 intercostal nerves in a randomized, patient- and observer-masked fashion. Participants all received a continuous paravertebral block with ropivacaine, 0.2%, until the early morning of discharge (usually postoperative day 2). The primary endpoint was the average pain level measured using a 0 to 10 numeric rating scale the afternoon of postoperative day 2. Participants were followed for 1 yr. RESULTS: On postoperative day 2, participants who had received active cryoneurolysis (n = 31) had a median [interquartile range] pain score of 0 [0 to 1.4] versus 3.0 [2.0 to 5.0] in patients given sham (n = 29): difference -2.5 (97.5% CI, -3.5 to -1.5), P < 0.001. There was evidence of superior analgesia through month 12. During the first 3 weeks, cryoneurolysis lowered cumulative opioid use by 98%, with the active group using 1.5 [0 to 14] mg of oxycodone compared with 72 [20 to 120] mg in the sham group (P < 0.001). No oral analgesics were required by any patient between months 1 and 12. After 1 yr chronic pain had developed in 1 (3%) active compared with 5 (17%) sham participants (P < 0.001). CONCLUSIONS: Percutaneous cryoneurolysis markedly improved analgesia without systemic side effects or complications after mastectomy.

A Randomized Controlled Pilot Study Using Ultrasound-Guided Percutaneous Cryoneurolysis of the Infrapatellar Branch of the Saphenous Nerve for Analgesia Following Total Knee Arthroplasty.

INTRODUCTION: Total knee arthroplasty (TKA) is frequently associated with severe, prolonged postsurgical pain, and therefore local anesthetic-based peripheral nerve blocks are commonly used for postoperative analgesia. Cryoneurolysis involves the use of freezing temperatures to provide a reversible sensory (and motor) block with a duration measured in weeks and months, more commensurate with the typical period of post-TKA pain. We therefore conducted a randomized controlled pilot study to evaluate the use of this modality for the treatment of pain following TKA to (1) determine the feasibility of and optimize the study protocol for a subsequent definitive clinical trial; and (2) estimate analgesia and opioid reduction within the first 3 postoperative weeks. METHODS: A convenience sample of 16 patients undergoing primary TKA with a single-injection and/or continuous adductor canal nerve block were randomized to receive either active cryoneurolysis or a sham procedure targeting the infrapatellar branch of the saphenous nerve, in a participant-masked fashion. This was a pilot study with a relatively small number of participants, and therefore resulting data were not analyzed statistically. RESULTS: Compared with participants receiving sham, the active treatment group reported slightly lower average and worst pain scores as well as opioid consumption and sleep disturbances due to pain at a majority of postoperative time points between postoperative days (POD) 4-21. CONCLUSIONS: Preoperative ultrasound-guided cryoneurolysis of the infrapatellar branch of the saphenous nerve is feasible and may provide analgesic benefits for multiple weeks following TKA. A definitive randomized controlled trial appears warranted.

Basal Infusion versus Automated Boluses and a Delayed Start Timer for "Continuous" Sciatic Nerve Blocks after Ambulatory Foot and Ankle Surgery: A Randomized Clinical Trial.

BACKGROUND: The common technique using a basal infusion for an ambulatory continuous peripheral nerve blocks frequently results in exhaustion of the local anesthetic reservoir before resolution of surgical pain. This study was designed to improve and prolong analgesia by delaying initiation using an integrated timer and delivering a lower hourly volume of local anesthetic as automated boluses. The hypothesis was that compared with a traditional continuous infusion, ropivacaine administered with automated boluses at a lower dose and 5-h delay would (1) provide at least noninferior analgesia (difference in average pain no greater than 1.7 points) while both techniques were functioning (average pain score day after surgery) and (2) result in a longer duration (dual primary outcomes). METHODS: Participants (n = 70) undergoing foot or ankle surgery with a popliteal-sciatic catheter received an injection of ropivacaine 0.5% with epinephrine (20 ml) and then were randomized to receive ropivacaine (0.2%) either as continuous infusion (6 ml/h) initiated before discharge or as automated boluses (8 ml every 2 h) initiated 5 h after discharge using a timer. Both groups could self-deliver supplemental boluses (4 ml, lockout 30 min); participants and outcome assessors were blinded to randomization. All randomized participants were included in the data analysis. RESULTS: The day after surgery, participants with automated boluses had a median [interquartile range] pain score of 0.0 [0.0 to 3.0] versus 3.0 [1.8 to 4.8] for the continuous infusion group, with an odds ratio of 3.1 (95% CI, 1.23 to 7.84; P = 0.033) adjusting for body mass index. Reservoir exhaustion in the automated boluses group occurred after a median [interquartile range] of 119 h [109 to 125] versus 74 h [57 to 80] for the continuous infusion group (difference of 47 h; 95% CI, 38 to 55; P < 0.001 adjusting for body mass index). CONCLUSIONS: For popliteal-sciatic catheters, replacing a continuous infusion initiated before discharge with automated boluses and a start-delay timer resulted in better analgesia and longer infusion duration.

Serratus anterior plane versus paravertebral nerve blocks for postoperative analgesia after non-mastectomy breast surgery: a randomized controlled non-inferiority trial.

BACKGROUND: Paravertebral and serratus plane blocks are both used to treat pain following breast surgery. However, it remains unknown if the newer serratus block provides comparable analgesia to the decades-old paravertebral technique. METHODS: Subjects undergoing unilateral or bilateral non-mastectomy breast surgery were randomized to a single-injection serratus or paravertebral block in a subject-masked fashion (ropivacaine 0.5%; 20 mL unilateral; 16 mL/side bilateral). We hypothesized that (1) analgesia would be non-inferior in the recovery room with serratus blocks (measurement: Numeric Rating Scale), and (2) opioid consumption would be non-inferior with serratus blocks in the operating and recovery rooms. In order to claim that serratus blocks are non-inferior to paravertebral blocks, both hypotheses must be at least non-inferior. RESULTS: Within the recovery room, pain scores for participants with serratus blocks (n=49) had a median (IQR) of 4.0 (0-5.5) vs 0 (0-3.0) for those with paravertebral blocks (n=51): 0.95% CI -3.00 to -0.00; p=0.001. However, the difference in morphine equivalents did not reach statistical significance for superiority with the serratus group consuming 14 mg (10-19) vs 10 mg (10-16) for the paravertebral group: 95% CI -4.50 to 0.00, p=0.123. Since the 95% CI lower limit of -4.5 was less than our prespecified margin of -2.0, we failed to conclude non-inferiority of the serratus block with regard to opioid consumption. CONCLUSIONS: Serratus blocks provided inferior analgesia compared with paravertebral blocks. Without a dramatic improvement in safety profile for serratus blocks, it appears that paravertebral blocks are superior to serratus blocks for postoperative analgesia after non-mastectomy breast surgery. TRIAL REGISTRATION NUMBER: NCT03860974.

The Implementation of an Acute Pain Service for Patients Undergoing Open Ventral Hernia Repair with Mesh and Abdominal Wall Reconstruction.

INTRODUCTION: In this retrospective cohort single-institutional study, we report the outcomes of implementing a standardized protocol of multimodal pain management with thoracic epidural analgesia via the acute pain service (APS) for patients undergoing ventral hernia repair with mesh placement and abdominal wall reconstruction. METHODS: The primary outcome evaluated was postoperative 72-h opioid consumption, measured in intravenous morphine equivalents (MEQ). Secondary outcomes included hospital length of stay (LOS) among other outcomes. The two cohorts were the APS versus non-APS group, in which the former cohort had an APS providing epidural and multimodal analgesia and the latter utilized pain management per surgical team, which mostly consisted of opioid therapy. Using1:1 propensity-score-matched cohorts, Wilcoxon signed-rank test was used to calculate the differences in outcomes. A p < 0.05 was considered statistically significant. RESULTS: There were 83 patients, wherein 51 (61.4%) were in the APS group. Between matched cohorts, the non-APS cohort's median [quartiles] total opioid consumption during the first three days was 85.6 mg MEQs [58.9, 112.8 mg MEQs]. The APS cohort was 31.7 mg MEQs [16.0, 55.3 mg MEQs] (p < 0.0001). The non-APS hospital LOS median [quartiles] was 5 days [4, 7 days] versus 4 days [4, 5 days] in the APS group (p = 0.01). DISCUSSION: A dedicated APS was associated with decreased opioid consumption by 75%, as well as a decreased hospital LOS. We report no differences in ICU length of stay, time to oral intake, time to ambulation or time to urinary catheter removal.

Continuous Paravertebral Nerve Block for Scapula Fracture Analgesia: A Case Report.

A 46-year-old man presented with severe refractory posterior shoulder pain due to a left scapular fracture sustained during a motor vehicle collision. Despite multimodal oral and intravenous analgesics, the patient's pain remained difficult to control. A continuous paravertebral nerve block was performed between the second and third thoracic vertebrae resulting in excellent analgesia of the scapular pain. This case suggests that a continuous thoracic paravertebral block placed between the second and third vertebrae may be considered as part of multimodal analgesia in patients with scapular fractures.

Utilization of regional anesthesia for open reduction and internal fixation of clavicular fractures is associated with increased same-day discharge and not readmissions.

BACKGROUND: Regional anesthesia is becoming increasingly used for analgesia in clavicular surgery. The purpose of the study is to examine same-day discharge and readmissions in patients with clavicular fractures receiving open reduction and internal fixation, comparing those who received regional anesthesia to those that did not. METHODS: The National Surgical Quality Improvement Program registry was used to build a retrospective cohort with the primary and secondary outcomes of same-day discharge and readmission rates, respectively. The independent variable was type of anesthesia (ie, regional vs general). Unadjusted univariable followed by multivariable logistic regression analysis for the association of each covariate with the primary and secondary outcome was performed. A p<0.05 was considered statistically significant. RESULTS: A total of 2300 patients were included, in which 346 (15.0%) of received a nerve block. The only factor associated with same-day discharge on crude analysis was the use of a nerve block (OR 1.70, 95% CI 1.21 to 2.40, p<0.01). Factors not associated with same-day discharge included geriatric age (OR 0.39, 95% CI 0.26 to 0.57, p<0.01), diabetes mellitus (OR 0.54, 95% CI 0.33 to 0.89, p=0.01), dependent functional status (OR 0.27, 95% CI 0.11 to 0.69, p<0.01), hypertension (OR 0.39, 95% CI 0.29 to 0.52, p<0.01), bleeding disorder (OR 0.24, 95% CI 0.10 to 0.59, p<0.01) and an American Society of Anesthesiologists Physical Status score ≥3 (OR 0.33, 95% CI 0.25 to 0.45, p<0.01). On adjusted analysis, regional anesthesia was associated with increased odds of same-day discharge (OR 1.67, 95% CI 1.18 to 2.37, p<0.01), but not 30-day readmission (OR 0.57, 95% CI 0.13 to 2.52, p=0.46). CONCLUSION: Regional anesthesia use in patients with clavicular fractures is associated with higher odds for same-day discharge. There is no significant difference in the rates of hospital readmission within a 30-day period. LEVEL OF EVIDENCE: IV, retrospective case series.

Suture-method versus Through-the-needle Catheters for Continuous Popliteal-sciatic Nerve Blocks: A Randomized Clinical Trial.

BACKGROUND: The basic perineural catheter design has changed minimally since inception, with the catheter introduced through or over a straight needle. The U.S. Food and Drug Administration recently cleared a novel perineural catheter design comprising a catheter attached to the back of a suture-shaped needle that is inserted, advanced along the arc of its curvature pulling the catheter past the target nerve, and then exited through the skin in a second location. The authors hypothesized that analgesia would be noninferior using the new versus traditional catheter design in the first two days after painful foot/ankle surgery with a primary outcome of average pain measured with the Numeric Rating Scale. METHODS: Subjects undergoing painful foot or ankle surgery with a continuous supraparaneural popliteal-sciatic nerve block 5 cm proximal to the bifurcation were randomized to either a suture-type or through-the-needle catheter and subsequent 3-day 0.2% ropivacaine infusion (basal 6 ml/h, bolus 4 ml, lockout 30 min). Subjects received daily follow-up for the first four days after surgery, including assessment for evidence of malfunction or dislodgement of the catheters. RESULTS: During the first two postoperative days the mean ± SD average pain scores were lower in subjects with the suture-catheter (n = 35) compared with the through-the-needle (n = 35) group (2.7 ± 2.4 vs. 3.4 ± 2.4) and found to be statistically noninferior (95% CI, -1.9 to 0.6; P < 0.001). No suture-style catheter was completely dislodged (0%), whereas the tips of three (9%) traditional catheters were found outside of the skin before purposeful removal on postoperative day 3 (P = 0.239). CONCLUSIONS: Suture-type perineural catheters provided noninferior analgesia compared with traditional catheters for continuous popliteal-sciatic blocks after painful foot and ankle surgery. The new catheter design appears to be a viable alternative to traditional designs used for the past seven decades.

Erector spinae plane versus paravertebral nerve blocks for postoperative analgesia after breast surgery: a randomized clinical trial.

BACKGROUND: Paravertebral nerve blocks (PVBs) are frequently used to treat pain during and following breast surgery, but have various undesirable risks such as pneumothorax. The erector spinae plane block (ESPB) also provides perioperative breast analgesia, but is purported to be easier to administer with a favorable safety profile. However, it remains unknown if the new ESPB provides comparable analgesia as the decades-old PVB technique. METHODS: Subjects undergoing unilateral or bilateral non-mastectomy breast surgery were randomized to a single-injection ESPB or PVB in a subject-blinded fashion (ropivacaine 0.5% with epinephrine; 20 mL unilateral or 16 mL/side for bilateral). We hypothesized that (1) analgesia would be non-inferior in the recovery room as measured on a Numeric Rating Scale (NRS) with ESPB, and (2) opioid consumption would be non-inferior in the operating and recovery rooms with ESPB. RESULTS: Both pain scores and opioid consumption were higher in subjects with ESPBs (n=50) than PVBs (n=50; median NRS 3.0 vs 0; 95% CI -3.0 to 0; p=0.0011; and median morphine equivalents 2.0 vs 1.5 mg; 95% CI -1.2 to -0.1; p=0.0043). No block-related adverse events occurred in either group. CONCLUSIONS: PVBs provided superior analgesia and reduced opioid requirements following non-mastectomy breast surgery. To compare the relatively rare complications between the techniques will require a sample size 1-2 orders of magnitude greater than the current investigation; however, without a dramatic improvement in safety profile for ESPBs, it appears that PVBs are superior to ESPBs for postoperative analgesia after non-mastectomy breast surgery. TRIAL REGISTRATION NUMBER: NCT03549234.

Ultrasound-Guided Lateral Femoral Cutaneous Nerve Cryoneurolysis for Analgesia in Patients With Burns.

Autologous skin grafting from the thigh is frequently required for treatment of burns and is associated with intense pain at the donor site. Local anesthetic-based (LA) nerve blocks of the lateral femoral cutaneous nerve (LFCN) have been demonstrated to provide analgesia when the graft is taken from the lateral thigh. However, the duration of these single injection blocks has been reported to average only 9 hours, whereas the pain from the procedure lasts days or weeks. Continuous LA nerve blocks can also be used to provide analgesia during serial debridement of burns, although this requires placement of a perineural catheter which may increase infection risk in a population with an increased susceptibility to infection. Cryoneurolysis of the LFCN can potentially provide analgesia of the lateral thigh for skin graft harvesting or serial burn debridement that lasts far longer than conventional LA nerve blocks. Here, we present a series of three patients who received a combination of a LA nerve block and cryoneurolysis nerve block of the LFCN for analgesia of the lateral thigh. Two of these patients had the blocks placed before harvesting a split thickness skin graft. The third received the blocks for outpatient wound care of a burn to the lateral thigh. In all cases, the resulting analgesia lasted more than 1 week. A single cryoneurolysis block of the LFCN successfully provided extended duration analgesia of the lateral thigh for autologous skin graft donor site or wound care of a burn in three patients.

Ultrasound-guided percutaneous intercostal nerve cryoneurolysis for analgesia following traumatic rib fracture -a case series.

BACKGRUOND: Rib fractures are a common injury in trauma patients and account for significant morbidity and mortality within this population. Local anesthetic-based nerve blocks have been demonstrated to provide significant pain relief and reduce complications. However, the analgesia provided by these blocks is limited to hours for single injection blocks or days for continuous infusions, while the duration of this pain often lasts weeks. CASE: This case series describes five patients with rib fractures whose pain was successfully treated with cryoneurolysis. CONCLUSIONS: Ultrasound-guided percutaneous cryoneurolysis is a modality that has the potential to provide analgesia matching the duration of pain following rib fractures.

Association of trainee involvement in an acute pain service with postoperative opioid use in patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Several hospitals have implemented a multidisciplinary Acute Pain Service (APS) to execute surgery-specific opioid sparing analgesic pathways. Implementation of an anesthesia attending-only APS has been associated with decreased postoperative opioid consumption, time to ambulation, and time to solid food intake for patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy. In this study, we evaluated the impact of introducing an APS trainee on postoperative opioid consumption in patients undergoing hyperthermic intraperitoneal chemotherapy during POD 0-3. METHODS: We performed a retrospective propensity-matched cohort study where we compared opioid consumption and hospital length of stay among two historical cohorts: attending-only APS service versus service involving a regional anesthesia fellow. RESULTS: In the matched cohorts, the median postoperative day (POD) 0-3 opioid use [25%, 75% quartile] for the single attending and trainee involvement cohort were 38.5 mg morphine equivalents (MEQ) [14.1 mg, 106.3 mg] and 50.4 mg MEQ [28.4 mg, 91.2 mg], respectively. The median difference was -9.8 mg MEQ (95% CI -30.7-16.5 mg; P = 0.43). There was no difference in hospital length of stay between both cohorts (P = 0.67). CONCLUSIONS: We found that the addition of a regional anesthesia fellow to the APS team was not associated with statistically significant differences in total opioid consumption or hospital length of stay in this surgical population. The addition of trainees to the infrastructure, with vigilant supervision, is not associated with change in outcomes.