A Change in the Educational Landscape of Regional Anesthesia: A National Survey of Anesthesiology Residency Programs to Assess the Correlation Between the Frequency of Teaching a Block Technique and Clinical Importance.

Introduction Variability regarding which blocks are performed most often can be quite high among anesthesiology residency training programs. Which techniques are viewed by residency programs as "critical" for their graduates to know can also be inconsistent. We administered a national survey to investigate correlations between the cited importance of techniques and the relative frequency with which they are being taught. Materials and methods A three-round modified Delphi method was used to develop the survey. The final survey was sent to 143 training programs across the United States. The surveys collected information on the frequency with which thoracic epidural blocks, truncal blocks, and peripheral blocks were taught. The respondents were also asked to rate how critical each technique is to learn during residency. A correlation between the relative frequency of block teaching and cited importance to education was calculated using Kendall's Tau statistic. Results Among truncal procedures, transversus abdominis plane (TAP) block and thoracic epidural blocks were frequently viewed as "indispensable for daily practice." Among peripheral nerve blocks, interscalene, supraclavicular, adductor, and popliteal blocks were frequently viewed as indispensable. All truncal blocks showed a strong correlation between the relative frequency of block teaching and cited importance to education. However, the frequency of teaching interscalene, supraclavicular, femoral, and popliteal blocks failed to correlate with their reported importance ranking. Conclusions Perceived importance was significantly associated with the reported frequency of block teaching for all truncal and peripheral blocks except for interscalene, supraclavicular, femoral, and popliteal. The lack of correlation between the frequency of teaching and perceived importance is reflective of a changing educational landscape.

Anomalous Course of the Brachial Plexus Identified During Ultrasound-Guided Brachial Plexus Nerve Block.

Knowledge of brachial plexus anatomy is essential when performing upper-extremity regional anaesthesia. Anomalous brachial plexus anatomy has been reported in up to 35% of patients. Variants include anomalous course of the roots anterior to, or within, the scalene musculature and abnormal separation of the cords around the subclavian artery. These anomalies have been detected with ultrasound, a valuable tool for delineating anatomy and providing imaging guidance during regional anaesthesia. We report a previously undescribed course of the brachial plexus relative to the subclavian artery within the supraclavicular fossa identified by ultrasound prior to peripheral nerve blockade.

Regional anesthesia in patients with Charcot-Marie-Tooth disease: a historical cohort study of 53 patients.

PURPOSE: Anesthetic management for patients with Charcot-Marie-Tooth disease (CMT) is controversial. Description of the use of regional anesthesia (RA) in patients with CMT is limited. Regional anesthesia has traditionally been avoided because of risk of nerve injury. We retrospectively reviewed patients with CMT who received RA at our institution. METHODS: We performed a historical cohort study of all patients with CMT who received RA from 30 April 2010 to 30 April 2020 within our institution. Charts were reviewed for information on demographics, RA procedures, perioperative variables, evidence of neurologic complications, post-RA neurology consults, and perioperative electromyography (EMG) results. Electromyographs were reviewed by a neurologist who was blinded to the surgical and RA details. RESULTS: Fifty-three patients received a total of 132 regional anesthetics during the study period. Twenty-five patients received RA on more than one occasion. Fifty-five EMGs and 14 postoperative neurology consults were performed. Two patients had neurology consults with peripheral nerve block (PNB) distribution complaints years later. Neither attributed the complaints to the PNB. The other neurology consults were for unrelated complaints. No EMG results suggested injury related to PNB. CONCLUSION: This study found no evidence of documented neurologic complications or an increased risk of nerve injury related to RA in CMT patients.

RéSUMé: OBJECTIF: La prise en charge anesthésique des patients atteints de la maladie de Charcot-Marie-Tooth (CMT) est controversée. Les descriptions de l'utilisation de l'anesthésie régionale (AR) chez les patients atteints de CMT sont limitées. L'anesthésie régionale est traditionnellement évitée en raison du risque de lésion nerveuse. Nous avons rétrospectivement passé en revue les dossiers des patients atteints de CMT ayant reçu une AR dans notre établissement. MéTHODE: Nous avons réalisé une étude de cohorte historique de tous les patients atteints de CMT ayant reçu une AR entre le 30 avril 2010 et le 30 avril 2020 au sein de notre établissement. Les dossiers ont été passés en revue pour en tirer des renseignements sur les données démographiques, les interventions d'AR, les variables périopératoires, les signes de complications neurologiques, les consultations en neurologie post-AR et les résultats de l'électromyographie (EMG) périopératoire. Les électromyographes ont été examinés par un neurologue qui n'avait pas accès aux détails concernant la chirurgie et l'AR. RéSULTATS: Cinquante-trois patients ont reçu un total de 132 anesthésies régionales au cours de la période d'étude. Vingt-cinq patients ont reçu une AR à plus d'une occasion. Cinquante-cinq EMG et 14 consultations postopératoires en neurologie ont été effectuées. Deux patients ont consulté en neurologie après s'être plaints de la distribution du bloc nerveux périphérique (BNP) des années plus tard. Ni l'un ni l'autre n'a attribué ces problèmes au BNP. Les autres consultations en neurologie concernaient des plaintes non liées au BNP. Aucun résultat d'EMG n'a suggéré de lésion liée au BNP. CONCLUSION: Cette étude n'a trouvé aucune preuve de complications neurologiques documentées ou d'un risque accru de lésion nerveuse liée à l'AR chez les patients atteints de CMT.

Oxygen delivery failure due to improper installation of carbon dioxide absorbent canister: a case report.

The CLIC system in the Dräger Apollo anesthesia workstation allows a successful pre-use machine checkout without the presence of a carbon dioxide absorbent canister. It also allows the canister to be changed without interrupting controlled ventilation. However, this canister can be easily installed improperly with the CLIC adapter. We report a case in which a patient could not be ventilated by mask after the induction of general anesthesia, resulting in oxygen desaturation before successful ventilation was achieved with a bag valve mask. This case illustrates the importance of a leak test after components of the breathing circuit are changed.

Forced-Air Convection Versus Underbody Conduction Warming Strategies to Maintain Perioperative Normothermia in Patients Undergoing Total Joint Arthroplasty.

Background Forced-air warming is an established strategy for maintaining perioperative normothermia. However, this warming strategy can potentially contaminate the surgical field by circulating nonsterile air. This study aimed to determine whether changing practice away from this method resulted in non-inferior rates of perioperative hypothermia. Methods We performed a chart review of primary total hip and knee arthroplasty patients from 2014 to 2017, when the strategy of intraoperative forced-air warming (FAW) was changed to preoperative FAW along with intraoperative underbody conduction warming (CW) with an underbody warming mattress. Data included patient temperatures throughout all phases of care, blood loss and transfusion requirements, length of postanesthesia care unit (PACU) and hospital stays, and 30-day infection and mortality. Results A total of 769 charts were reviewed; 349 patients underwent surgery before the practice change and 420 after. Mean (SD; 95% CI) body temperatures at the time of incision were lower for group 1 than for group 2 (34.55 vs 35.52 °C [0.97 °C; 95% CI, 0.72-1.23 °C]). The average nadir of intraoperative body temperature was lower for group 1 than for group 2 (difference of means, 0.44 °C; 95% CI, 0.18-0.71 °C). Group 2 had a higher percentage of patients who presented hypothermic (temperature <36.0 °C) on arrival in the PACU (12.9% vs 7.7%). Conclusion Preoperative convective warming combined with intraoperative underbody conductive warming maintains normothermia during primary total joint arthroplasty and is non-inferior to forced-air intraoperative warming alone.

Paravertebral block for radiologically inserted gastrostomy tube placement in amyotrophic lateral sclerosis.

INTRODUCTION: Radiologically inserted gastrostomy (RIG) placement in patients with amyotrophic lateral sclerosis (ALS) carries risks related to periprocedural sedation and analgesia. To minimize these risks, we used a paravertebral block (PVB) technique for RIG placement. METHODS: We retrospectively reviewed patients with ALS undergoing RIG placement under PVB between 2013 and 2017. RESULTS: Ninety-nine patients with ALS underwent RIG placement under PVB. Median (range) age was 66 (28 to 86) years, ALS Functional Rating Scale-Revised score was 27 (6 to 45), and forced vital capacity was 47% (8%-79%) at time of RIG placement. Eighty-five (85.9%) patients underwent RIG placement as outpatients, with a mean postanesthesia care unit stay of 2.3 hours. The readmission rate was 4% at both 1 and 30 days postprocedure. DISCUSSION: PVB for RIG placement has a low rate of adverse events and provides effective periprocedural analgesia in patients with ALS, the majority of whom can be treated as outpatients.

The Role of Regional versus General Anesthesia on Arteriovenous Fistula and Graft Outcomes: A Single-Institution Experience and Literature Review.

BACKGROUND: Multiple studies have demonstrated the benefits of creating arteriovenous fistulas (AVFs) under regional anesthesia. This is most likely because of the avoidance of hemodynamic instability and stress response of general anesthesia, as well as the sympathectomy associated with brachial plexus blockade. As vein diameter is the major limiting factor for primary AVF creation and maturation, our aim is to investigate if the vasodilation that accompanies regional anesthesia leads to improved patency and maturation rate of autologous AVF and improved patency of arteriovenous graft (AVG) compared with those placed under general anesthesia. METHODS: This retrospective study was approved by the institutional review board. A total of 238 patients who had either an AVF or an AVG placed at the Mayo Clinic, Florida, between 2012 and 2017 were analyzed. Demographics, access type, preoperative vein diameter, anesthesia type, change of plan after regional versus general anesthesia, and outcomes were assessed. All statistical tests were 2 sided, with the alpha level set at 0.05 for statistical significance. RESULTS: Among 238 patients, 120 (50.4%) had regional anesthesia. Differences between the 2 groups in risk factors and 30-day or long-term outcomes (failure, abandonment, or reoperation) were not statistically significant. Of the accesses placed under general anesthesia, 58.5% were abandoned compared with 45.2% of those placed under regional anesthesia. Owing to loss of patency, 25.8% of accesses placed under general anesthesia were abandoned compared with 19.2% of those placed under regional anesthesia. Two-month failure was higher in the general anesthesia group than that in the regional anesthesia group (P = 0.076). After preoperative vein mapping, 22 patients were originally intended to have an AVG placed under regional anesthesia. After brachial plexus blockade, 9 of these patients (41%) were successfully switched to AVF, while the other 13 followed the original surgical plan and received an AVG. Of these, 0 failed and 0 were abandoned because of loss of patency. CONCLUSIONS: This study showed possible improvements in failure rates for vascular accesses placed under regional anesthesia compared with those placed under general anesthesia. In addition, we showed an impact of regional anesthesia on the surgical plan by transitioning from a planned AVG to an AVF, intraoperatively. Giving patients with originally inadequate vein diameter the chance to have the preferred hemodialysis access method by simply switching anesthesia type could reduce the number of grafts placed in favor of fistulas.

Tranexamic Acid Administration Is Not Associated With an Increase in Complications in High-Risk Patients Undergoing Primary Total Knee or Total Hip Arthroplasty: A Retrospective Case-Control Study of 38,220 Patients.

BACKGROUND: Tranexamic acid (TXA) administration to reduce postoperative blood loss and transfusion is a well-established practice for total knee arthroplasty (TKA) and total hip arthroplasty (THA). However, clinical concerns remain about the safety of TXA in patients with a history of a prothrombotic condition. We sought to determine the risk of complications between high-risk and low-risk TKA and THA patients receiving TXA. METHODS: We retrospectively reviewed 38,220 patients (8877 high-risk cases) who underwent primary TKA and THA between 2011 and 2017 at our institution. Intravenous TXA was administered in 20,501 (54%) of cases. The rates of thrombotic complications (deep vein thrombosis [DVT], pulmonary embolism [PE], myocardial infarction [MI], and cerebrovascular accident [CVA]) as well as mortality and readmission were assessed at 90 days postoperatively. Additionally, we evaluated 90-day postoperative occurrence of DVT and PE separate from occurrence of MI and CVA. Patients were categorized as high risk if they had a past medical history of a prothrombotic condition prior to surgery. RESULTS: There was no significant difference in the odds of these adverse outcomes between high-risk patients who received TXA and high-risk patients who did not receive TXA (odds ratio [OR] 1.00, 95% confidence interval [CI] 0.85-1.18). There were also no differences when evaluating the odds of 90-day postoperative DVT and PE (OR 0.84, 95% CI 0.59-1.19) nor MI and CVA (OR 0.91, 95% CI 0.56-1.49) for high-risk patients receiving TXA vs high-risk patients who did not receive TXA. CONCLUSION: TXA administration to high-risk TKA and THA patients is not associated with a statistically significant difference in adverse outcomes. We present incremental evidence in support of TXA administration for high-risk patients undergoing primary arthroplasties.

Gastric emptying of "clear liquid drinks" assessed with gastric ultrasonography: a blinded, randomized pilot study.

BACKGROUND: Protein-containing liquids may delay gastric emptying and increase risk of aspiration. Commercial whey protein nutritional drinks (WPNDs) are advertised as "clear liquid nutritional drinks" and can be mistaken for protein-free, carbohydrate-based clear liquids. We used gastric ultrasonography to compare gastric emptying of a protein-free, carbohydrate-based clear liquid with that of a WPND in healthy volunteers. METHODS: We recruited 19 adult (age ≥18 years) volunteers with a body mass index less than 40 kg/m2 and without a history of diabetes mellitus, dysphagia, prior gastric surgery, or allergy to the ingredients of apple juice (AJ) or a WPND. After fasting for eight hours, the volunteers randomly received 474 mL of AJ or a WPND. Gastric ultrasonographic measurements were obtained at baseline and at 0, 30, 60, and 120 minutes after ingestion of the liquid. RESULTS: We enrolled 19 volunteers. At 120 minutes after consumption, volunteers who ingested a WPND had a larger estimated gastric volume (GV) than volunteers who ingested AJ (median [interquartile range], 101.3 [70.0-137.4] vs. 50.6 [43.9-81.8] mL; P=.08). By using the 2-sample t test and an α level of .05, we determined that the study had 40% power to detect a significant difference in GV. Future studies need to include 24 participants per group to detect a significant difference. CONCLUSIONS: Although consumption of a WPND was associated with a larger estimated GV in this pilot study, a larger study is necessary to conclude whether patients must fast longer than two hours after consumption of a WPND.

Peripheral Nerve Blocks and Immediate Postoperative Recovery: A Single-Institution Survey of Perianesthesia Nurses' Preferences and Opinions.

PURPOSE: To ascertain the preferences of perianesthesia nurses regarding peripheral nerve blocks (PNBs) and their impact on patient recovery after total joint replacement (TJR). DESIGN: Survey of perianesthesia nurses at a single medical center. METHODS: Fifty-nine perianesthesia nurses completed a 23-question survey on PNBs for TJR. FINDINGS: Most agreed PNBs improved patients' pain after knee, hip, and shoulder TJR (35 [92.1%], 35 [92.1%], and 34 [91.9%], respectively). Most felt lower extremity PNBs increased risk of falling (26 [70.3%]), whereas 7 of 35 (20.0%) felt patients fell more after spinal anesthesia than after general anesthesia. Respondents preferred a block to opioid-based analgesia if they were to have lower extremity TJR or total shoulder replacement (100% [30/30 and 33/33]). CONCLUSIONS: The perianesthesia nurses surveyed felt PNBs improved pain control and patient recovery despite a perceived risk of falling for lower extremity TJR, and they preferred PNB when considering TJR surgery for themselves.

Ultrasound Assessment of Gastric Volume After Bariatric Surgery: A Case Report.

Gastric ultrasound is emerging as a tool that can be used to assess gastric content and volume in patients with an unknown fasting history. This information can impact the choice of anesthetic technique or the timing of surgery due to the presumed risk of aspiration. Currently, no data are available regarding the use of gastric ultrasound for patients who have had prior gastric operations, despite the increasing number of patients undergoing bariatric surgery. Our experience suggests that a patient with a prior Roux-en-Y gastric bypass may present with altered anatomy, rendering gastric ultrasound an ineffective technique to assess the volume of ingested food or liquid.

The effect of scoliosis on surface landmarks for lumbar plexus block: a MRI-based retrospective case-control series.

BACKGROUND: Degenerative scoliosis (DS) may affect surface landmarks for performance of lumbar plexus (LP) block. We hypothesized the extent of any difference in surface landmarks could be calculated by a formula based on measured degree of DS, body mass index, sex, and age. METHODS: We retrospectively searched our radiology database until 113 consecutive adult patients with DS were identified with lumbar spine radiographs and magnetic resonance imaging examinations performed. Pertinent surface landmark measurements at the L4 vertebral body level were recorded and compared to 50 controls. RESULTS: In patients with severe DS, there is a mean lateral deviation of the needle tip of 1.53 cm (0-3 cm) on the concave side and mean medial deviation of the needle tip of 0.35 cm (0-1.5 cm) on the convex side using typical bony landmarks. We found a significant correlation between body mass index and LP depth with a correlation coefficient ranging between 0.53 and 0.71. We found potential risk of organ injury in two of 13 patients with severe DS using traditional surface landmarks. CONCLUSIONS: There is a larger degree of lateral deviation of the LP on the concave side of scoliosis compared to medial deviation on the convex side. These deviations remained consistent irrespective of the direction of scoliosis. A review of the imaging studies and preprocedural ultrasound assessment of anatomy should be strongly considered prior to needle puncture. In patients with severe DS, an alternative approach may be considered to avoid the possibility of visceral organ injury.

Clinical application of limiting laryngeal mask airway cuff pressures utilizing inflating syringe intrinsic recoil.

BACKGROUND: Overinflation of the laryngeal mask airway (LMA) cuff may cause many of the complications associated with the use of the LMA. There is no clinically acceptable (cost effective and practical) method to ensure cuff pressure is maintained below the manufacturer's recommended maximum value of 60 cm H2O (44 mmHg). We studied the use of the intrinsic recoil of the LMA inflating syringe as an effective and practical way to limit cuff pressures at or below the manufacturer's recommended values. METHODS: We enrolled 332 patients into three separate groups: LMAs inserted and inflated per standard practice at the institution with only manual palpation of the pilot balloon; LMA cuff pressures measured by a pressure transducer and reduced to < 60 cm H2O (44 mmHg); and LMA intra-cuff pressure managed by the intrinsic recoil of the syringe. RESULTS: There were no statistically significant differences between the pressure transducer group and the syringe recoil group for initial cuff pressure or cuff pressure 1 hour after surgery. Both the syringe recoil group and pressure transducer group were less likely than the standard practice group to have sore throat and dysphagia 1 hour after surgery. These differences remained 24 hours after surgery. CONCLUSIONS: Syringe recoil provides an efficient and reproducible method similar to manometry in preventing overinflation of the LMA cuff and decreasing the incidence of postoperative laryngopharyngeal complications.

Peripheral nerve blocks and postoperative physical therapy: a single-institution survey of physical therapists' preferences and opinions.

BACKGROUND AND AIMS: Our aim was to ascertain the opinions and preferences of physical therapists with regard to use of peripheral nerve blocks and their impact on the recovery of patients undergoing total joint replacement. METHODS: We conducted an anonymous 24-question survey of 20 full-time inpatient physical therapists at a single tertiary care medical center. RESULTS: One respondent indicated they never work with patients who have undergone total joint replacement surgery. Nineteen questionnaires were included in the final analysis. Questions omitted by respondents or with write-in answers were not included in the analysis. A majority of respondents (15 [78.9%]) agreed nerve blocks somewhat to greatly improve a patient's pain after total joint replacement surgery. Most respondents answered that nerve blocks somewhat to greatly impede a patient's ability to participate in physical therapy (14 [73.6%]) and make therapy somewhat to very difficult for them as physical therapists (16 [84.2%]). When asked about specific surgeries, (17/18 [94.4%]) and (14/18 [77.8%]) of respondents would prefer that their patients receive periarticular infiltration or no block at all after total knee arthroplasty or total hip arthroplasty, respectively. All respondents (19 [100%]) answered that they thought lower extremity nerve blocks increased a patient's risk of falling after surgery. CONCLUSIONS: According to the physical therapists we surveyed, nerve blocks impede patient recovery and increase the risk of falls, despite their positive impact on pain control. When considering surgery for themselves, therapists indicated they would not want a nerve block.

ANESTHETIC MANAGEMENT OF FEMORAL FRACTURE REPAIR IN A PATIENT WITH CERVICAL MYELOPATHY, AUTONOMIC DYSFUNCTION, AND DIFFICULT AIRWAY.

Spinal stenosis is a potentially serious condition that can lead to myelopathies and autonomic instability, both of which, as a result, may complicate anesthetic management. Additionally, neuraxial anesthesia appears to increase the risk of worsened neurological outcomes in this population. A 56-year-old female with spinal stenosis, autonomic dysfunction, and known difficult airway who required anesthesia for repair of a femur fracture is presented. After pre-operative arterial line and femoral block placement, an ultrasound guided subarachnoid block was safely placed. This supports the notion that in the appropriate setting, a safe, successful neuraxial blockade can be performed when a general anesthetic may be fraught with more risk.

Whole-exome sequencing of a family with local anesthetic resistance.

BACKGROUND: Local anesthetics (LA) work by blocking sodium conductance through voltage-gated sodium channels. Complete local anesthetic resistance is infrequent, and the cause is unknown. Genetic variation in sodium channels is a potential mechanism for local anesthetic resistance. A patient with a history of inadequate loss of sensation following LA administration underwent an ultrasound-guided brachial plexus nerve block with a complete failure of the block. We hypothesized that LA resistance is due to a variant form of voltage-gated sodium channel. METHODS: Whole-Exome Sequencing. The patient and her immediate family provided consent for exome sequencing, and they were screened with a questionnaire to identify family members with a history of LA resistance. Exome sequencing results for four individuals were referenced to the 1000 Genomes Project and the NHLBI ESP to identify variants associated with local anesthetic resistance present in less than 1% of the general population and located in functional regions of the genome. RESULTS: Exome sequencing of the four family members identified one genetic variant in the voltage-gated sodium channel shared by the three individuals with LA resistance but not present in the unaffected family member. Specifically, we noted the A572D mutation in the SCN5A gene encoding for Nav1.5. CONCLUSIONS: We identified a genetic variant that is associated with LA resistance in the gene encoding for Nav1.5. We also demonstrate that Nav1.5 is present in human peripheral nerves to support the plausibility that an abnormal form of the Nav1.5 protein could be responsible for the observed local anesthetic resistance.