Retrospective Review of Intrathecal Hydromorphone Dose Range and Complications.

BACKGROUND: Optimal intrathecal dosing regimens for hydromorphone are not well established for analgesia after abdominal surgery. OBJECTIVES: We reviewed intrathecal hydromorphone doses and complications because dosing variability has been observed among anesthesiologists. We hypothesized that increasing doses of intrathecal hydromorphone would be associated with improved postoperative analgesia, but with increased rates of opioid-related adverse events. STUDY DESIGN: Retrospective analysis. SETTING: A high-volume academic referral center in the United States. METHODS: A retrospective study was conducted of adults undergoing abdominal surgery under general anesthesia supplemented preoperatively with intrathecal hydromorphone for postoperative analgesia from May 5, 2018, through May 31, 2021. Patients were categorized into 3 hydromorphone dosing groups: low-dose (50-100 µg), middle-dose (101-199 µg), and high-dose (200-300 µg). Multivariable logistic regression models were used to assess rates of severe postoperative pain, severe opioid-related adverse events, oversedation, and pruritus in the postanesthesia care unit (PACU) and within 24 hours after PACU discharge. RESULTS: Of 1,846 patients identified, 1,235 (66.9%) were in the low-dose group; 321 (17.3%), middle-dose group; and 290 (15.7%), high-dose group. Patients receiving the 2 higher doses had more extensive procedures. An unadjusted analysis showed differing rates of severe pain in the PACU by group: 306 (24.8%) in the low-dose, 73 (22.7%) middle-dose, and 45 (15.5%) in the high-dose group (P = 0.003); these differences, however, were no longer significant after an adjusted analysis (P = 0.34). Ten severe opioid-related events occurred; all were recognized in the PACU. Five events each occurred in the low-dose and high-dose groups versus none in the middle-dose group (P = 0.02). No other differences were identified with adjusted analyses. LIMITATIONS: Limitations of our study include its retrospective design and its conduct at a single center, along with the apparent, but difficult to characterize, treatment biases in hydromorphone dosing. CONCLUSIONS: No dose response was observed between intrathecal hydromorphone dose and postoperative analgesia, a finding that may reflect treatment bias. Higher rates of severe opioid-related events were detected for patients receiving high-dose hydromorphone in the PACU, but all other safety outcomes were similar between dosing regimens. KEY WORDS: Drug-related side effects, opioid analgesics, outcome assessment, postoperative pain, spinal injections.

Effect of an oxytocin protocol on secondary uterotonic use in patients undergoing Cesarean delivery.

PURPOSE: Protocol-driven oxytocin regimens can reduce oxytocin administration compared with a nonprotocol free-flow continuous infusion. Our aim was to compare secondary uterotonic use between a modified "rule of threes" oxytocin protocol and a free-flow continuous oxytocin infusion after Cesarean delivery. METHODS: We conducted a retrospective before-and-after study to compare patients who underwent Cesarean delivery between 1 January 2010 and 31 December 2013 (preprotocol) with patients who underwent Cesarean delivery between 1 January 2015 and 31 August 2017 (postprotocol). The preprotocol group received free-flow oxytocin administration and the postprotocol group received oxytocin according to a modified rule of threes algorithm. The primary outcome was secondary uterotonic use and the secondary outcomes included blood transfusion, hemoglobin value < 8 g·dL-1, and estimated blood loss. RESULTS: In total, 4,010 Cesarean deliveries were performed in 3,637 patients (2,262 preprotocol and 1,748 postprotocol). The odds of receiving secondary uterotonic drugs were increased in the postprotocol group (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.04 to 1.70; P = 0.02). Patients in the postprotocol group were less likely to receive a blood transfusion. Nevertheless, the two groups were similar for the composite end point of transfusion or hemoglobin < 8 g·dL-1 (OR, 0.86; 95% CI, 0.66 to 1.11; P = 0.25). The odds of an estimated blood loss greater than 1,000 mL were reduced in the postprotocol group (OR, 0.64; 95% CI, 0.50 to 0.84; P = 0.001). CONCLUSIONS: Patients in the modified rule of threes oxytocin protocol group were more likely to receive a secondary uterotonic than those in the preprotocol group. Estimated blood loss and transfusion outcomes were similar.

RéSUMé: OBJECTIF: Les schémas thérapeutiques d'ocytocine basés sur un protocole peuvent réduire l'administration d'ocytocine par rapport à une perfusion continue en débit libre hors protocole. Notre objectif était de comparer l'utilisation secondaires d'agents utérotoniques entre un protocole modifié d'ocytocine en « règle de trois ¼ et une perfusion continue d'ocytocine à débit libre après un accouchement par césarienne. MéTHODE: Nous avons mené une étude rétrospective avant-après pour comparer les personnes ayant bénéficié d'une césarienne entre le 1er janvier 2010 et le 31 décembre 2013 (pré-protocole) avec les personnes ayant subi une césarienne entre le 1er janvier 2015 et le 31 août 2017 (post-protocole). Le groupe pré-protocole a reçu une administration d'ocytocine en débit libre et le groupe post-protocole a reçu de l'ocytocine selon un algorithme de règle de trois modifié. Le critère d'évaluation principal était l'utilisation secondaire d'agents utérotoniques et les critères d'évaluation secondaires incluaient la transfusion sanguine, un indice d'hémoglobine < 8 g·dL­1 et les pertes de sang estimées. RéSULTATS: Au total, 4010 accouchements par césarienne ont été réalisés chez 3637 patient·es (2262 pré-protocole et 1748 post-protocole). Les chances de recevoir des médicaments utérotoniques secondaires étaient plus élevées dans le groupe post-protocole (rapport de cotes [RC], 1,33; intervalle de confiance [IC] à 95 %, 1,04 à 1,70; P = 0,02). Les patient·es du groupe post-protocole étaient moins susceptibles de recevoir une transfusion sanguine. Néanmoins, les deux groupes étaient similaires en ce qui touchait au critère d'évaluation composite de transfusion ou d'hémoglobine < 8 g·dL­1 (RC, 0,86; IC 95, 0,66 à 1,11; P = 0,25). Les risques d'une perte de sang estimée supérieure à 1000 mL ont été réduits dans le groupe post-protocole (RC, 0,64; IC 95 %, 0,50 à 0,84; P = 0,001). CONCLUSION: Les patient·es du groupe du protocole d'ocytocine en règle de trois modifiée étaient plus susceptibles de recevoir un utérotonique secondaire que les personnes du groupe pré-protocole. Les pertes sanguines estimées et les résultats transfusionnels étaient similaires.

Simulation Training Effects on Resident-Perceived Readiness for Obstetric Anesthesia Rotation.

Background: Beginning an unfamiliar rotation can be challenging as residents must expand their knowledge and skills to meet new clinical expectations, work with a new team of providers, and sometimes care for a new patient demographic. This may detract from learning, resident well-being, and patient care. Methods: We implemented an obstetric anesthesia simulation session for anesthesiology residents prior to their first obstetric anesthesia rotation and measured the effect on residents' self-perceived preparedness. Results: The simulation session increased residents' feelings of preparedness for the rotation and increased residents' confidence in specific obstetric anesthesia skills. Conclusions: Importantly, this study shows the potential for the use of a prerotation, rotation-specific simulation session to better prepare learners for rotations.

Obstetric Anesthetic Management for Parturients with Hereditary Angioedema: A Case Report and Suggested Protocol.

Hereditary angioedema (HAE) is a disease manifested by repeated episodes of localized submucosal or subcutaneous edematous episodes, potentially triggered by emotional stress, mechanical trauma, or intake of estrogens. We present our experience managing two parturients with HAE. Multidisciplinary care is essential for planning and executing the specialized care of these patients, and management included extensive planning among obstetric, anesthesiology, and allergy and immunology teams. Pregnancy has been shown to have a variable effect on triggering HAE episodes. First-line treatment includes C1 esterase inhibitor concentrate, which can also be used for prophylaxis in high-risk patients. Neuraxial analgesia is recommended to avoid general anesthesia and was established early in both individuals. Vaginal delivery was well tolerated without need for emergent treatment for angioedema symptoms.

Intravenous Dexmedetomidine as an Adjunct to Neuraxial Anesthesia in Cesarean Delivery: A Retrospective Chart Review.

BACKGROUND: Dexmedetomidine is a selective α-2 agonist commonly used for sedation that has been used in obstetric anesthesia for multimodal labor analgesia, postcesarean delivery analgesia, and perioperative shivering. This study evaluated the role of intravenous dexmedetomidine to provide rescue analgesia and/or sedation during cesarean delivery under neuraxial anesthesia. METHODS: We conducted a single-center, retrospective cohort study of all parturients undergoing cesarean delivery under neuraxial anesthesia between December 1, 2018, and November 30, 2019, who required supplemental analgesia during the procedure. Patients were divided into two groups: patients who received intravenous dexmedetomidine (Dexmed group) and patients who received adjunct medications such as fentanyl, midazolam, ketamine, and nitrous oxide (Standard group). Primary outcome was incidence of conversion to general anesthesia. RESULTS: During the study period, 107 patients received adjunct medications. There was no difference in conversion to general anesthesia between the Dexmed group and the Standard group (6% (4/62) vs. 9% (4/45); p=0.718). In the Dexmed group, the mean dexmedetomidine dose received was 37 µg (range 10 to 140 µg). While the use of inotropic/vasopressor medications was common and similar in both groups, there was an increase in the incidence of bradycardia (Dexmed 15% vs. Standard 2%; p=0.042) but not hypotension (Dexmed 24% vs. Standard 24%; p=1.00) in the Dexmed group. CONCLUSION: In patients who required supplemental analgesia for cesarean delivery, those who received dexmedetomidine versus other medications had a similar rate of conversion to general anesthesia, a statistically significant increase in bradycardia, but no difference in the incidence of hypotension.

Effect of penicillin allergy on prophylactic antibiotic administration in the parturient undergoing cesarean delivery.

BACKGROUND: Administering antibiotics is often difficult in patients with specific medication allergies. This investigation aimed to determine if a penicillin or cephalosporin allergy increased the risk for not receiving correct timing of prophylactic antibiotics at cesarean delivery. We hypothesized that patients with a penicillin or cephalosporin allergy would be less likely to receive antibiotics prior to incision for cesarean delivery. METHODS: All women undergoing cesarean delivery at Mayo Clinic Hospital, from 1 March 2008, to 28 February 2018 were retrospectively identified by electronic medical record query. Patients were grouped based on allergy status to penicillin/cephalosporins. Data recorded included the type and time of antibiotic given in relation to surgical incision. The primary outcome of this study was administration of antibiotics within 60 minutes prior to surgical incision. Characteristics potentially associated with the primary outcome were assessed using logistic regression. RESULTS: Of the 818 patients with a penicillin or cephalosporin allergy, 75 (9.2%) did not receive prophylactic antibiotic within 60 minutes prior to skin incision. Conversely, 326 (6.9%) of the 4744 patients without a penicillin or cephalosporin allergy did not receive their prophylactic antibiotic within 60 minutes prior to skin incision (P = .019). Patients undergoing an emergent cesarean delivery were also at an increased risk of not receiving their prophylactic antibiotic within 60 minutes prior to skin incision (P < .001). CONCLUSION: Patients with a penicillin or cephalosporin allergy were less likely to receive prophylactic antibiotics within the recommended 60 minutes prior to surgical incision. Clear plans and communication are important for ensuring proper antibiotic administration at cesarean delivery to prevent surgical site infection.

Complication rate of ultrasound-guided paravertebral block for breast surgery.

BACKGROUND AND OBJECTIVES: Thoracic paravertebral blockade is often used as an anesthetic and/or analgesic technique for breast surgery. With ultrasound guidance, the rate of complications is speculated to be lower than when using landmark-based techniques. This investigation aimed to quantify the incidence of pleural puncture and pneumothorax following non-continuous ultrasound-guided thoracic paravertebral blockade for breast surgery. METHODS: Patients who received thoracic paravertebral blockade for breast surgery were identified by retrospective query of our institution's electronic database over a 5-year period. Data collected included patient demographics, level of block, type and volume of local anesthetic, occurrence of pleural puncture, occurrence of pneumothorax, evidence of local anesthetic toxicity, and patient vital signs. The incidence of block complications, including pleural puncture, pneumothorax, and local anesthetic toxicity, were ascertained. RESULTS: 529 patients underwent 2163 thoracic paravertebral injections. Zero pleural punctures were identified during block performance; however, two patients were found to have a pneumothorax on postoperative chest X-ray (3.6 per 1000 surgeries, 95% CI 0.5 to 13.6; 0.9 per 1000 levels blocked, 95% CI 0.1 to 3.3). There were no cases of local anesthetic systemic toxicity or associated lipid emulsion therapy administration. CONCLUSIONS: Pneumothorax following non-continuous ultrasound-guided thoracic paravertebral block using a parasagittal approach is an uncommon occurrence, with a similar rate to pneumothorax following breast surgery alone.

In Utero Restoration of Hindbrain Herniation in Fetal Myelomeningocele as Part of Prenatal Regenerative Therapy Program at Mayo Clinic.

OBJECTIVE: To assess our initial experience with prenatal restoration of hindbrain herniation following in utero repair of myelomeningocele (MMC). PATIENTS AND METHODS: Three consecutive patients with prenatally diagnosed MMC (between January 1, 2018 and September 30, 2018) were managed with open in utero surgery. As per institutional review board approval and following a protocol designed at the Mayo Clinic Maternal & Fetal Center, fetal intervention was offered between 19 0/7 and 25 6/7 weeks of gestation. Prenatal improvement of hindbrain herniation was the declared restorative end point. Obstetrical and perinatal outcomes were also assessed. RESULTS: Diagnosis of MMC was confirmed upon referral between 20 and 21 weeks' gestation by using fetal ultrasound and magnetic resonance imaging. In all cases reported here, the spinal defect was lumbosacral with evidence of hindbrain herniation. Open in utero MMC repair was performed between 24 and 25 weeks' gestation with no notable perioperative complications. Postprocedure fetal magnetic resonance imaging performed 6 weeks after in utero repair documented improvement of hindbrain herniation. Deliveries were at 37 weeks by cesarean section without complications. Most recent postnatal follow-ups were unremarkable at both 11 months (baby 1) and 3 months of age (baby 2), with mild ventriculomegaly. Antenatal and postnatal follow-up of baby 3 at 1 month of age was also unremarkable. CONCLUSION: Our study highlights the prenatal restoration of hindbrain herniation following in utero MMC repair in all cases presented here as an example of a prenatal regenerative therapy program in our institution.

Intrathecal Morphine versus Intrathecal Hydromorphone for Analgesia after Cesarean Delivery: A Randomized Clinical Trial.

BACKGROUND: Intrathecal opioids are routinely administered during spinal anesthesia for postcesarean analgesia. The effectiveness of intrathecal morphine for postcesarean analgesia is well established, and the use of intrathecal hydromorphone is growing. No prospective studies have compared the effectiveness of equipotent doses of intrathecal morphine versus intrathecal hydromorphone as part of a multimodal analgesic regimen for postcesarean analgesia. The authors hypothesized that intrathecal morphine would result in superior analgesia compared with intrathecal hydromorphone 24 h after delivery. METHODS: In this single-center, double-blinded, randomized trial, 138 parturients undergoing scheduled cesarean delivery were randomized to receive 150 µg of intrathecal morphine or 75 µg of intrathecal hydromorphone as part of a primary spinal anesthetic and multimodal analgesic regimen; 134 parturients were included in the analysis. The primary outcome was the numerical rating scale score for pain with movement 24 h after delivery. Static and dynamic pain scores, nausea, pruritus, degree of sedation, and patient satisfaction were assessed every 6 h for 36 h postpartum. Total opioid consumption was recorded. RESULTS: There was no significant difference in pain scores with movement at 24 h (intrathecal hydromorphone median [25th, 75th] 4 [3, 5] and intrathecal morphine 3 [2, 4.5]) or at any time point (estimated difference, 0.5; 95% CI, 0 to 1; P = 0.139). Opioid received in the first 24 h did not differ between groups (median [25th, 75th] oral morphine milligram equivalents for intrathecal hydromorphone 30 [7.5, 45.06] vs. intrathecal morphine 22.5 [14.0, 37.5], P = 0.769). From Kaplan-Meier analysis, the median time to first opioid request was 5.4 h for hydromorphone and 12.1 h for morphine (log-rank test P = 0.200). CONCLUSIONS: Although the hypothesis was that intrathecal morphine would provide superior analgesia to intrathecal hydromorphone, the results did not confirm this. At the doses studied, both intrathecal morphine and intrathecal hydromorphone provide effective postcesarean analgesia when combined with a multimodal analgesia regimen.

A 3-arm randomized clinical trial comparing interscalene blockade techniques with local infiltration analgesia for total shoulder arthroplasty.

BACKGROUND: The ideal analgesic modality for total shoulder arthroplasty (TSA) remains controversial. We hypothesized that a multimodal analgesic pathway incorporating continuous interscalene blockade (ISB) provides better analgesic efficacy than both single-injection ISB and local infiltration analgesia. METHODS: This single-center, parallel, unblinded, randomized clinical trial evaluated 129 adults undergoing primary TSA. Patients were allocated to single-injection ISB, continuous ISB, or local infiltration analgesia. The primary outcome was the Overall Benefit of Analgesia Score (range, 0 [best] to 28 [worst]) on postoperative day 1. Additional outcomes included pain scores, opioid consumption, quality of life, and postoperative complications in the first 24 hours, at 3 months, and at 1 year. RESULTS: We analyzed 125 patients (42 with single-injection ISB, 41 with continuous ISB, and 42 with local infiltration analgesia). The Overall Benefit of Analgesia Score was significantly improved in the continuous group (median [25th percentile, 75th percentile], 0 [0, 2]) compared with the single-injection group (2 [1, 4]; P = .002) and local infiltration analgesia group (3 [2, 4]; P < .001). Pain scores were significantly lower in the continuous group compared with the local infiltration analgesia group (P < .001 for all time points) and after 12 hours from ward arrival compared with the single-injection group (median [25th percentile, 75th percentile], 1.0 [0.0, 2.8] vs. 2.5 [0.0, 4.0]; P = .016). After postanesthesia recovery discharge, opioid consumption (oral morphine equivalents) was significantly lower in the continuous group (median [25th percentile, 75th percentile], 7.5 mg [0.0, 25.0 mg]) than in the local infiltration analgesia group (30 mg [15.0, 52.5 mg]; P < .001) and single-injection group (17.6 mg [7.5, 45.5 mg]; P = .010). No differences were found across groups for complications, 3-month outcomes, and 1-year outcomes. CONCLUSION: Continuous ISB provides superior analgesia compared with single-injection ISB and local infiltration analgesia in the first 24 hours after TSA.

Fetoscopic Therapy for Severe Pulmonary Hypoplasia in Congenital Diaphragmatic Hernia: A First in Prenatal Regenerative Medicine at Mayo Clinic.

OBJECTIVE: To introduce the prenatal regenerative medicine service at Mayo Clinic for fetal endoscopic tracheal occlusion (FETO) care for severe congenital diaphragmatic hernia (CDH). PATIENTS AND METHODS: Two cases of prenatal management of severe CDH with FETO between January and August 2017 are reported. Per protocol, FETO was offered for life-threatening severe CDH at between 26 and 29 weeks' gestation. Regenerative outcome end point was fetal lung growth. Gestational age at procedure and maternal and perinatal outcomes were additional monitored parameters. RESULTS: Diagnosis by ultrasonography of severe CDH was based on extremely reduced lung size (observed-to-expected lung area to head circumference ratio [o/e-LHR], eg, o/e-LHR of 20.3% for fetus 1 and 23.0% for fetus 2) along with greater than one-third of the liver herniated into the chest in both fetuses. Both patients underwent successful FETO at 28 weeks. At the time of intervention, no maternal or fetal complications were observed. Postintervention, fetal lung growth was observed in both fetuses, reaching an o/e-LHR of 62.7% at 36 weeks in fetus 1 and 52.4% at 32 weeks in fetus 2. The balloons were removed successfully at 35 weeks and 4 days by ultrasound-guided puncture in the first patient and at 32 weeks and 3 days by ex utero intrapartum therapy-to-airway procedure in the second patient. Postnatal management followed standard of care with patch CDH therapy. At discharge, one patient was breathing normally, whereas the other required minimal nasal cannula oxygen support. CONCLUSION: The successful launch of the first fetoscopic therapy for CDH at Mayo Clinic reveals its feasibility and safety, with early signs of benefit documented by fetal lung growth and reversal of severe pulmonary hypoplasia. TRIAL REGISTRATION: clinicaltrials.gov Identifier: G170062.

Infraclavicular versus axillary nerve catheters: A retrospective comparison of early catheter failure rate.

STUDY OBJECTIVES: Continuous brachial plexus catheters are often used to decrease pain following elbow surgery. This investigation aimed to assess the rate of early failure of infraclavicular (IC) and axillary (AX) nerve catheters following elbow surgery. DESIGN: Retrospective study. SETTING: Postoperative recovery unit and inpatient hospital floor. PATIENTS: 328 patients who received IC or AX nerve catheters and underwent elbow surgery were identified by retrospective query of our institution's database. MEASUREMENTS: Data collected included unplanned catheter dislodgement, catheter replacement rate, postoperative pain scores, and opioid administration on postoperative day 1. Catheter failure was defined as unplanned dislodging within 24 h of placement or requirement for catheter replacement and evaluated using a covariate adjusted model. MAIN RESULTS: 119 IC catheters and 209 AX catheters were evaluated. There were 8 (6.7%) failed IC catheters versus 13 (6.2%) failed AX catheters. After adjusting for age, BMI, and gender there was no difference in catheter failure rate between IC and AX nerve catheters (p = 0.449). CONCLUSIONS: These results suggest that IC and AX nerve catheters do not differ in the rate of early catheter failure, despite differences in anatomic location and catheter placement techniques. Both techniques provided effective postoperative analgesia with median pain scores < 3/10 for patients following elbow surgery. Reasons other than rate of early catheter failure should dictate which approach is performed.

Continuous Posterior Lumbar Plexus Nerve Block Versus Periarticular Injection with Ropivacaine or Liposomal Bupivacaine for Total Hip Arthroplasty: A Three-Arm Randomized Clinical Trial.

BACKGROUND: Debate surrounds the issue of whether peripheral nerve blockade or periarticular infiltration (PAI) should be employed within a contemporary, comprehensive multimodal analgesia pathway for total hip arthroplasty. We hypothesized that patients treated with a continuous posterior lumbar plexus block (PNB) would report less pain and consume less opioid medication than those treated with PAI. METHODS: This investigator-initiated, independently funded, 3-arm randomized clinical trial (RCT) performed at a single high-volume institution compared postoperative analgesia interventions for elective, unilateral primary total hip arthroplasty: (1) PNB; (2) PAI with ropivacaine, ketorolac, and epinephrine (PAI-R); and (3) PAI with liposomal bupivacaine, ketorolac, and epinephrine (PAI-L) using computerized randomization. The primary outcome was maximum pain during the morning (06:00 to 12:00) of the first postoperative day (POD) on an ascending numeric rating scale (NRS) from 0 to 10. Pairwise treatment comparisons were performed using the rank-sum test, with a p value of <0.017 indicating significance (Bonferroni adjusted). A sample size of 150 provided 80% power to detect a difference of 2.0 NRS units. RESULTS: We included 159 patients (51, 54, and 54 patients in the PNB, PAI-R, and PAI-L groups, respectively). No significant differences were found with respect to the primary end point on the morning of the first POD (median, 3.0, 4.0, and 3.0, respectively; p > 0.033 for all). Opioid consumption was low and did not differ across groups at any intervals. Median maximum pain on POD 1 was 5.0, 5.5, and 4.0, respectively, and was lower for the PAI-L group than for the PAI-R group (p = 0.006). On POD 2, maximum pain (median, 3.5, 5.0, and 3.5, respectively) was lower for the PNB group (p = 0.014) and PAI-L group (p = 0.016) compared with the PAI-R group. The PAI-L group was not significantly different from the PNB group with respect to any outcomes: postoperative opioid use including rescue intravenous opioid medication, length of stay, and hospital adverse events, and 3-month follow-up data including any complication. CONCLUSIONS: In this RCT, we found a modest improvement with respect to analgesia in patients receiving PNB compared with those receiving PAI-R, but not compared with those who had PAI-L. Secondary analyses suggested that PNB or PAI-L provides superior postoperative analgesia compared with PAI-R. For primary total hip arthroplasty, a multimodal analgesic regimen including PNB or PAI-L provides opioid-limiting analgesia. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Parturient recall of neuraxial analgesia risks: Impact of labor pain vs no labor pain.

STUDY OBJECTIVE: Information exchange between anesthesia providers and parturients about neuraxial analgesia risks often occurs in the presence of labor pain. This study examined whether the presence of pain impacted the level of recall of information provided to parturients regarding risks of neuraxial techniques. DESIGN: Single-center, nonrandomized study. SETTING: Labor and delivery suite and postpartum patient rooms in a large academic medical center. PATIENTS: Two hundred six primigravidas admitted to our labor and delivery suites and receiving neuraxial analgesia were included. INTERVENTIONS: Informed consent for epidural and spinal placement was obtained by an obstetric anesthesia resident as per our standard practice. At the time of consent, parturients' self-reported level of pain was recorded. MEASUREMENTS: After delivery, patients completed a questionnaire asking which risks they recalled. Also queried were patient self-reported levels of anxiety at the time of consent, patient satisfaction with the informed consent process, overall satisfaction with pain control, as well as their preferred method and timing of information exchange. MAIN RESULTS: Only 20.9% of the 206 participating parturients recalled all risks and none of the distractors. There was no difference in recall between those with pain and those without pain at the time of consent. Women experiencing any pain at the time of consent were more likely to be very satisfied with the communication of risks compared with women without pain (96.2% vs 85.5%, P=.005). There was no difference in the preferred method (P=.780) or timing (P=.779) of discussion of risks between women in active labor compared with women with a scheduled induction of labor. CONCLUSIONS: Although parturients' recall of neuraxial risks did not differ based on the existence of labor pain, those having pain reported greater satisfaction with the informed consent process.

Perioperative Nerve Injury After Peripheral Nerve Block in Patients With Previous Systemic Chemotherapy.

BACKGROUND AND OBJECTIVES: There are multiple risk factors for developing perioperative nerve injury (PNI). Perioperative nerve injury after peripheral nerve blockade (PNB) is rare. Exposure to systemic chemotherapy may cause peripheral neuropathy, but its role as a risk factor for PNI after PNB is unknown. The objective of this retrospective study was to determine the incidence of PNI in patients undergoing PNB as part of extremity surgery after prior exposure to systemic chemotherapy. METHODS: All patients aged 18 years or older who received systemic chemotherapy and subsequently underwent PNB were identified. The primary outcome was defined as the presence of new or worsened PNI documented within 3 months of the procedural date. Cases of PNI were independently reviewed by 3 investigators, and the etiology of all PNI cases were categorized as possibly or unlikely related to the PNB. RESULTS: A total of 216 PNB (165 lower extremity blocks, 51 upper extremity blocks) were performed in 186 patients previously exposed to chemotherapy; 4 cases met criteria for PNI (2.2%; 95% confidence interval, 0.8%-5.4%). One case of PNI was possibly related to PNB (0.5%; 95% confidence interval, 0.1%-3.0%) and 3 cases were unlikely related to PNB. Complete recovery occurred in 3 cases, with partial recovery occurring in 1. CONCLUSIONS: The overall incidence of PNI in this cohort (2.2%) was not different than baseline risk established in large cohort studies. Perioperative nerve injury was possibly attributable to the PNB in 0.5% of patients. However, in the absence of a control group of surgical patients who previously received systemic chemotherapy without regional anesthesia, we cannot determine whether the higher incidence of neurologic injury is secondary to the surgical procedure, the anesthetic technique, the natural progression of chemotherapy-induced peripheral neuropathy, or a combination of factors and the relative contribution of each.

A peer-designed selective in anesthesiology, critical care, and perioperative medicine for first- and second-year medical students.

STUDY OBJECTIVE: The objective of this study was to design and implement a preclinical elective (termed selective) in anesthesiology, critical care, and perioperative medicine and to report survey results assessing the impact of the selective on first- and second-year medical students' understanding of basic concepts, comfort with procedural skills, and interest in the specialty. DESIGN: Preinvention and postintervention survey evaluation was used as the design of this study. SETTING: The study was conducted at Mayo Medical School and Mayo Clinic. PARTICIPANTS: The participants in this study are first- and second-year medical students. INTERVENTIONS: A 1-week introductory anesthesiology curriculum was developed to include didactic sessions, shadowing experiences, lunch and dinner panels, mentorship and networking opportunities, and procedural workshops in airway management, ultrasound, and vascular access techniques. MEASUREMENTS: Preselective and postselective surveys using a 10-point scale (1, strongly disagree; 10, strongly agree) were administered 1 week before and after the selective. MAIN RESULTS: A total of 8 students participated in the selective, with a 100% survey response rate. Students reported significant increases for all survey questions regarding basic concepts and skills. The largest increases were reported in comfort with airway management skills, understanding of the perioperative surgical home model, and vascular access skills. All participants indicated a higher likelihood of pursuing anesthesiology as a career and attributed their increased interest in anesthesiology to the selective. CONCLUSIONS: This new selective was successful in giving first- and second-year medical students a comprehensive overview of anesthesiology and increasing medical student interest in the specialty. The success of this selective leads to promising belief that similar peer-designed educational experiences can be developed at other medical schools to improve education and interest in this area of medicine.

A rare combination of undiagnosed hypertrophic cardiomyopathy revealed by intraoperative anaphylaxis resulting in acute left ventricular outflow obstruction and cardiac arrest.

A 75-year-old female presented for left total hip reimplantation and suffered pulseless electrical activity arrest upon lateral positioning and administering vancomycin. Resuscitation was achieved according to Advanced Cardiac Life Support protocol. Post-event echocardiography showed hypertrophic cardiomyopathy with asymmetrical septal thickening, an under-filled left ventricle, dynamic left ventricular outflow obstruction, and severe mitral regurgitation related to systolic anterior motion of the mitral valve. Laboratory analysis showed a tryptase level of 209 ng/mL. After multispecialty evaluation, it was concluded that the patient's arrest was due to vancomycin anaphylaxis in the setting of previously undiagnosed hypertrophic cardiomyopathy leading to acute left ventricular outflow tract obstruction. After medical optimization of the patient's cardiomyopathy and an evaluation of potential intraoperative allergic triggers, the patient underwent a successful hip reimplantation without incident. This case presents a novel combination of events leading to intraoperative cardiac arrest. Rapid identification and an understanding of the cause(s) of cardiac arrest in this setting are critical for effective perioperative care.

Intrathecal Hydromorphone and Morphine for Postcesarean Delivery Analgesia: Determination of the ED90 Using a Sequential Allocation Biased-Coin Method.

BACKGROUND: Intrathecal (IT) morphine is considered the "gold standard" for analgesia after cesarean delivery under spinal anesthesia, most commonly administered at a dose of 100 to 200 µg. There is less experience with IT hydromorphone for postcesarean analgesia and limited information on its optimal analgesic dose. We conducted this study to determine the effective analgesic dose for 90% patients (ED90) of IT hydromorphone that provides effective analgesia for women undergoing elective cesarean delivery and its potency ratio to IT morphine. METHODS: In this dose-finding trial, 80 patients received spinal anesthesia for cesarean delivery. Participants were randomized to receive IT morphine or IT hydromorphone at a dose determined using up-down sequential allocation with a biased-coin design to determine ED90. All patients received standardized multimodal analgesia postoperatively in addition to IT opioid. An effective dose was defined as a numeric response score for pain of ≤3 (scale 0-10) 12 hours after spinal injection. RESULTS: The ED90 was 75 µg (95% confidence interval [CI], 46-93 µg) for IT hydromorphone and 150 µg (95% CI, 145-185 µg) for IT morphine. At these doses, the 95% CI for the percentage of patients with effective analgesia (numeric rating scale ≤3) was 64% to 100% for hydromorphone and 68% to 100% for morphine. Exploratory findings showed that the incidence of nausea and pruritus was not different among the most commonly used doses of IT hydromorphone (P = 0.44 and P = 0.74) or IT morphine (P = 0.67 and P = 0.38, respectively). When administering IT opioids at ED90 doses or higher, 100% (21/21) of IT hydromorphone and 95% (37/39) of IT morphine patients were satisfied with their analgesia. CONCLUSIONS: The ratio of IT morphine to IT hydromorphone for effective postcesarean analgesia is 2:1. Patient satisfaction was high with both medications.

Velamentous Umbilical Cord Insertion and Ruptured Fetal Vessel: A Cause of Fetal-Maternal Hemorrhage: A Case Report.

Background: Fetal hemorrhage is rare but can result in rapid fetal compromise. Abnormally located fetal vessels within the membranes increase the risk for their rupture and subsequent hemorrhage. The classic example of this is vasa previa. Case: We present a case of acute fetal hemorrhage resulting from a ruptured fetal vessel. During induction of labor, significant fetal heart rate deceleration occurred, coinciding with acute vaginal bleeding and amniotomy. A depressed, live female neonate was delivered by emergency cesarean section. Examination of the placenta revealed a velamentous cord insertion and a ruptured fetal vessel coursing through the chorioamniotic membranes. Neonatal resuscitation included red blood cell transfusion for hypotension and low hematocrit. The neonate made a full recovery. Conclusion: Acute fetal hemorrhage from the rupture of aberrant fetal vessels often coincides with rupture of membranes. Identifying ruptured fetal vessels abnormally coursing through the chorioamniotic membranes on examination of the placenta provides supporting evidence for suspected fetal hemorrhage.