Use of hydroxocobalamin to treat intraoperative vasoplegic syndrome refractory to vasopressors and methylene blue during liver transplantation.

INTRODUCTION: For patients with catecholamine-resistant vasoplegic syndrome (VS) during liver transplantation (LT), treatment with methylene blue (MB) and/or hydroxocobalamin (B12) has been an acceptable therapy. However, data on the effectiveness of B12 is limited to case reports and case series. METHODS: We retrospectively reviewed records of patients undergoing LT from January 2016 through March 2022. We identified patients with VS treated with vasopressors and MB, and abstracted hemodynamic parameters, vasopressor requirements, and B12 administration from the records. The primary aim was to describe the treatment efficacy of B12 for VS refractory to vasopressors and MB, measured as no vasopressor requirement at the conclusion of the surgery. RESULTS: One hundred one patients received intraoperative VS treatment. For the 35 (34.7%) patients with successful VS treatment, 14 received MB only and 21 received both MB and B12. Of the 21 patients with VS resolution after receiving both MB and B12, 17 (89.5%) showed immediate, but transient, hemodynamic improvements at the time of MB administration and later showed sustained response to B12. CONCLUSION: Immediate but transient hemodynamic response to MB in VS patients during LT supports the diagnosis of VS and should prompt B12 administration for sustained treatment response.

Comparison of onset of neuromuscular blockade with electromyographic and acceleromyographic monitoring: a prospective clinical trial.

BACKGROUND: Reliable devices that quantitatively monitor the level of neuromuscular blockade after neuromuscular blocking agents' administration are crucial. Electromyography and acceleromyography are two monitoring modalities commonly used in clinical practice. The primary outcome of this study is to compare the onset of neuromuscular blockade, defined as a Train-Of-Four Count (TOFC) equal to 0, as measured by an electromyography-based device (TetraGraph) and an acceleromyography-based device (TOFscan). The secondary outcome was to compare intubating conditions when one of these two devices reached a TOFC equal to 0. METHODS: One hundred adult patients scheduled for elective surgery requiring neuromuscular blockade were enrolled. Prior to induction of anesthesia, TetraGraph electrodes were placed over the forearm of patients' dominant/non-dominant hand based on randomization and TOFscan electrodes placed on the contralateral forearm. Intraoperative neuromuscular blocking agent dose was standardized to 0.5 mg.kg-1 of rocuronium. After baseline values were obtained, objective measurements were recorded every 20 seconds and intubation was performed using video laryngoscopy once either device displayed a TOFC = 0. The anesthesia provider was then surveyed about intubating conditions. RESULTS: Baseline TetraGraph train-of-four ratios were higher than those obtained with TOFscan (Median: 1.02 [0.88, 1.20] vs. 1.00 [0.64, 1.01], respectively, p < 0.001). The time to reach a TOFC = 0 was significantly longer when measured with TetraGraph compared to TOFscan (Median: 160 [40, 900] vs. 120 [60, 300] seconds, respectively, p < 0.001). There was no significant difference in intubating conditions when either device was used to determine the timing of endotracheal intubation. CONCLUSIONS: The onset of neuromuscular blockade was longer when measured with TetraGraph than TOFscan, and a train-of-four count of zero in either device was a useful indicator for adequate intubating conditions. CLINICAL TRIAL NUMBER AND REGISTRY: URL NCT05120999, https://clinicaltrials.gov/ct2/show/NCT05120999.

Comparison of onset of neuromuscular blockade with electromyographic and acceleromyographic monitoring: a prospective clinical trial

Abstract Background Reliable devices that quantitatively monitor the level of neuromuscular blockade after neuromuscular blocking agents' administration are crucial. Electromyography and acceleromyography are two monitoring modalities commonly used in clinical practice. The primary outcome of this study is to compare the onset of neuromuscular blockade, defined as a Train-Of-Four Count (TOFC) equal to 0, as measured by an electromyography-based device (TetraGraph) and an acceleromyography-based device (TOFscan). The secondary outcome was to compare intubating conditions when one of these two devices reached a TOFC equal to 0. Methods One hundred adult patients scheduled for elective surgery requiring neuromuscular blockade were enrolled. Prior to induction of anesthesia, TetraGraph electrodes were placed over the forearm of patients' dominant/non-dominant hand based on randomization and TOFscan electrodes placed on the contralateral forearm. Intraoperative neuromuscular blocking agent dose was standardized to 0.5 mg.kg−1 of rocuronium. After baseline values were obtained, objective measurements were recorded every 20 seconds and intubation was performed using video laryngoscopy once either device displayed a TOFC = 0. The anesthesia provider was then surveyed about intubating conditions. Results Baseline TetraGraph train-of-four ratios were higher than those obtained with TOFscan (Median: 1.02 [0.88, 1.20] vs. 1.00 [0.64, 1.01], respectively, p < 0.001). The time to reach a TOFC = 0 was significantly longer when measured with TetraGraph compared to TOFscan (Median: 160 [40, 900] vs. 120 [60, 300] seconds, respectively, p < 0.001). There was no significant difference in intubating conditions when either device was used to determine the timing of endotracheal intubation. Conclusions The onset of neuromuscular blockade was longer when measured with TetraGraph than TOFscan, and a train-of-four count of zero in either device was a useful indicator for adequate intubating conditions. Clinical trial number and registry URL NCT05120999, https://clinicaltrials.gov/ct2/show/NCT05120999.

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.

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.

Patient Survey of Referral From One Surgeon to Another to Reduce Maximum Waiting Time for Elective Surgery and Hours of Overutilized Operating Room Time.

BACKGROUND: Studies of shared (patient-provider) decision making for elective surgical care have examined both the decision whether to have surgery and patients' understanding of treatment options. We consider shared decision making applied to case scheduling, since implementation would reduce labor costs. METHODS: Study questions were presented in sequence of waiting times, starting with 4 workdays. "Assume the consultant surgeon (ie, the surgeon in charge) you met in clinic did not have time available to do your surgery within the next 4 workdays, but his/her colleague would have had time to do your surgery within the next 4 workdays. Would you have wanted to discuss with a member of the surgical team (eg, the scheduler or the surgeon) the availability of surgery with a different, equally qualified surgeon at Mayo Clinic who had time available within the next 4 workdays, on a date of your choosing?" There were 980 invited patients who underwent lung resection or cholecystectomy between 2011 and 2016; 135 respondents completed the study and 6 respondents dropped out after the study questions were displayed. RESULTS: The percentages of patients whose response to the study questions was "4 days" were 58.8% (40/68) among lung resection patients and 58.2% (39/67) among cholecystectomy patients. The 97.5% 2-sided confidence interval for the median maximum wait was 4 days to 4 days. Patients' choices for the waiting time sufficient to discuss having another surgeon perform the procedure did not differ between procedures (P = .91). Results were insensitive to patients' sex, age, travel time to hospital, or number of office visits before surgery (all P ≥ .20). CONCLUSIONS: Our results indicate that bringing up the option with the patient of changing surgeons when a colleague is available and has the operating room time to perform the procedure sooner is being respectful of most patients' individual preferences (ie, patient-centered).

Ultrasound-guided transversus abdominis plane blocks for patients undergoing laparoscopic hand-assisted nephrectomy: a randomized, placebo-controlled trial.

Postoperative pain is a common complaint following living kidney donation or tumor resection using the laparoscopic hand-assisted technique. To evaluate the potential analgesic benefit of transversus abdominis plane blocks, we conducted a randomized, double-blind, placebo-controlled study in 21 patients scheduled to undergo elective living-donor nephrectomy or single-sided nephrectomy for tumor. Patients were randomized to receive either 20 mL of 0.5% ropivacaine or 20 mL of 0.9% saline bilaterally to the transversus abdominis plane under ultrasound guidance. We found that transversus abdominis plane blocks reduced overall pain scores at 24 hours, with a trend toward decreased total morphine consumption. Nausea, vomiting, sedation, and time to discharge were not significantly different between the two study groups.