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.

Safety and Feasibility of a Fast-Track Pathway for Neurosurgical Craniotomy Patients: Bypassing the Intensive Care Unit.

Objective: To describe the safety and feasibility of a fast-track pathway for neurosurgical craniotomy patients receiving care in a neurosciences progressive care unit (NPCU). Patients and Methods: Traditionally, most craniotomy patients are admitted to the neurosciences intensive care unit (NSICU) for postoperative follow-up. Decreased availability of NSICU beds during the coronavirus disease-2019 delta surge led our team to establish a de-novo NPCU to preserve capacity for patients requiring high level of care and would bypass routine NSICU admissions. Patients were selected a priori by treating neurosurgeons on the basis of the potential need for high-level ICU services. After operation, selected patients were transferred to the postoperative care unit, where suitability for NPCU transfer was reassessed with checklist-criteria. This process was continued after the delta surge. Results: From July 1, 2021 to September 30, 2022, 57 patients followed the NPCU protocol. Thirty-four (59.6%) were women, and the mean age was 56 years. Fifty-seven craniotomies for 34 intra-axial and 23 extra-axial lesions were performed. After assessment and application of the checklist-criteria, 55 (96.5%) were transferred to NPCU, and only 2 (3.5%) were transferred to ICU. All 55 patients followed in NPCU had good safety outcomes without requiring NSICU transfer. This saved $143,000 and led to 55 additional ICU beds for emergent admissions. Conclusion: This fast-track craniotomy protocol provides early experience that a surgeon-selected group of patients may be suitably monitored outside the traditional NSICU. This system has the potential to reduce overall health care expenses, increase capacity for NSICU bed availability, and change the paradigm of NSICU admission.

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.

Perioperative Outcomes of Immersive Virtual Reality as Adjunct Anesthesia in Primary Total Hip and Knee Arthroplasty.

Background: Immersive virtual reality (IVR) is utilized as an adjunct to anesthesia to distract patients from their intraoperative environment, thereby potentially reducing sedative and narcotic medication usage. This study evaluated intraoperative and acute postoperative results of patients undergoing primary total hip (THA) and total knee arthroplasty (TKA) with and without IVR. Methods: Utilizing IVR as an adjunct to spinal anesthesia, 18 primary THAs (n = 8) and TKAs (n = 10) were performed. These cases were 1:2 matched based on procedure type, age, sex, and body mass index to those performed without IVR. Intraoperative and postanesthesia care unit sedative/narcotic usage, vital signs, and pain scores were compared. Acute perioperative outcomes, including 24-hour oral morphine equivalent (OME), first ambulation distance, length of stay, and 30-day complications, were also analyzed. Pearson Chi-square and Wilcoxon-Mann-Whitney tests evaluated categorical and continuous variables, respectively. Results: When compared to non-IVR primary THAs and TKAs, those performed with IVR utilized significantly less intraoperative sedation (48 mg vs 708 mg of propofol; P < .001) and trended toward less narcotic usage (13 mcg vs 39 mcg of fentanyl; P = .07). In the postanesthesia care unit, IVR and non-IVR patients showed no significant differences (P > .3) in vital signs, pain scores, or OME received. Additionally, similar (P > .3) postoperative outcomes were noted in both cohorts' 24-hour OME use, distance at first ambulation, length of stay, and 30-day complications. Conclusions: The use of spinal anesthesia with the IVR adjunct to perform primary THAs and TKAs appears to be well-tolerated and associated with less intraoperative sedative medication usage than spinal anesthesia alone.

Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) in type 1 thyroplasty.

INTRODUCTION: Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) has been shown to benefit oxygenation, ventilation, and upper airway patency in laryngeal surgery. Its use in thyroplasty procedures has not been described. We hypothesized that the addition of THRIVE during type 1 thyroplasty procedures increases patient's safety and decreases the risk of an obstructive airway, while also decreasing the FiO2 with potential pooling of oxygen under the drapes. METHODS: This was a retrospective study of 80 patients carried out at Mayo Clinic Florida. Use of THRIVE for thyroplasty surgeries was introduced by the authors in 2016. All cases between 2016 and 2021 were analyzed. Patients who underwent thyroplasty surgery without the use of THRIVE were included as a control group. RESULTS: A total of 80 patients underwent elective thyroplasty procedures, and 46 of them used the THRIVE technique. Median age was 61 years and 34 % were men. Patients with and without THRIVE were similar at baseline, but THRIVE patients had higher min SPO2 and lower HR end compared to patients without THRIVE. Normal BMI patients had significantly higher min SPO2 compared to either underweight or overweight BMI patients, but there was no strong linear relationship between BMI and intraoperative parameters. CONCLUSION: Our study is the first to demonstrate the use of THRIVE in type 1 thyroplasty in the literature. THRIVE facilitates oxygenation and ventilation of both the spontaneously breathing and the apneic patient. We have demonstrated that thyroplasty can be performed using high flow Optiflow® as the sole mechanism for oxygenation and ventilation.

Apneic Technique in Laryngotracheal Surgery.

Background Apneic oxygenation can be applied to select laryngotracheal procedures to improve operative visualization and avoid potential complications associated with intubation and jet ventilation.  Aims/objectives The authors sought to determine if apneic oxygenation using a high-flow nasal cannula could be used as a safe alternative airway management strategy for the duration of select laryngotracheal procedures. Methods Single institution, multi-site retrospective review of 38 adult (>18 years old) patients undergoing apneic oxygenation in the setting of various laryngotracheal procedures from January 2017 through January 2018. Humidified oxygen was delivered via a high-flow nasal cannula. The data was collected and analyzed using SAS version 9.4 (SAS Institute, Cary, NC). Results Twenty-four women and 14 men, mean age 60.0 years (SD 16.1; 36-89) and 70.1 years (SD 7.2; 56-81), respectively, underwent a mean total apneic time of 23.9 minutes (13-40). A statistically significant correlation existed between apneic time and minimum oxygen saturation (Pearson correlation coefficient 0.38; p=0.018). Twenty-one patients resumed spontaneous ventilation without the need for jet ventilation, mask ventilation, or placement of a definitive airway during the procedure.  Conclusions and significance Apneic oxygenation allows for extended periods of operating without the need for the placement of an endotracheal tube in patients undergoing general anesthesia for select laryngotracheal procedures.

Emergency Airway Management During Awake Craniotomy: Comparison of 5 Techniques in a Cadaveric Model.

BACKGROUND: During awake craniotomy, securing the patient's airway might be necessary electively or emergently. The objective of this study was to compare the feasibility of airway management using a laryngeal mask airway (LMA) and 4 alternative airway management techniques in an awake craniotomy simulation. METHODS: After completing a questionnaire, 9 anesthesia providers attempted airway management in a cadaver positioned to simulate awake craniotomy conditions. Following the simulation, participants rated and ranked the devices in their order of preference. RESULTS: Only 3 approaches resulted in the successful securement of an airway device for 100% of participants: LMA (median; interquartile range time to secure the airway 6 s, 5 to 10 s), fiberoptic bronchoscopy through an LMA (41 s; 23 to 51 s), and video laryngoscopy (49 s; 43 to 127 s). In contrast, the oral and nasal fiberoptic approaches demonstrated only 44.4% (154.5 s; 134.25 to 182 s) and 55.6% (75 s; 50 to 117 s) success rates, respectively. The LMA was the fastest and most reliable primary method to secure the airway (P=0.001). After the simulation, 100% of participants reported that an LMA would be their first choice for emergency airway management, followed by fiberoptic intubation through the LMA (7 of 9 participants) if the LMA failed to properly seat. CONCLUSIONS: We demonstrated that an LMA was the fastest and most reliable primary method to secure an airway in a laterally positioned cadaver with 3-pin skull fixation. Fiberoptic and video laryngoscope airway equipment should be readily available during awake craniotomy procedures, and an attempt to visualize the vocal cords through the LMA should be attempted before removing it for alternative techniques.

Immersive Virtual Reality Used as Adjunct Anesthesia for Conversion Total Hip Arthroplasty in a 100-Year-Old Patient.

Immersive virtual reality (IVR) is an adjunctive form of anesthesia intended to distract patients from their intraoperative environment and reduce other side effects of sedating or narcotic agents. While this technology has been applied sparingly in various orthopedic procedural environments, its clinical utility has not been widely evaluated in major, nonelective surgical settings. The use of IVR in the geriatric hip fracture population represents a novel indication with potential benefit to reduced cognitive dysfunction and delirium. We report a case of a 100-year-old patient who received IVR adjunctive to neuraxial anesthesia during conversion total hip arthroplasty via posterolateral approach for treatment of failed peritrochanteric hip fracture fixation.

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.

Oxygen therapy via a noninvasive helmet: A COVID-19 novelty with potential post-pandemic uses.

COVID-19 has placed a significant strain upon healthcare resources at a global level and refractory hypoxemia is the leading cause of death among COVID-19 patients. The management of limited resources such as mechanical ventilators has remained a contentious issue both at an individual and institutional level since the beginning of the pandemic. As a result, the COVID-19 pandemic has presented challenges to critical care practitioners to find innovative ways to provide supplemental oxygen therapy to their patients. We present a single-center experience: a case series of five COVID-19 infected patients managed with a novel approach to provide supplemental oxygen and positive end-expiration pressure (PEEP) via the helmet. Three of the five patients responded to therapy, did not require intubation, and survived to discharge. The other two patients continued to deteriorate clinically, required endotracheal intubation, and subsequently expired during their hospitalization. We extrapolated our accumulated experience with non-invasive oxygen support by helmet in COVID-19 patients to a non-COVID-19 postoperative patient who underwent sinus surgery and developed hypoxemic respiratory failure also resulting in avoidance of endotracheal intubation. We conclude that oxygen therapy via a helmet is a safe, cost-effective technique to prevent intubation in carefully selected patients with infectious and non-infectious causes of hypoxic respiratory failure. Our positive experience with the system warrants further large-scale study and possible technique refinement.

Management of Refractory Laryngospasm.

Laryngospasm has been well described in patients emerging from general anesthesia (GA) and is routinely managed with intermittent positive-pressure mask ventilation, a temporary increase in the depth of anesthesia, or small, titrated amounts of succinylcholine. Patients with severe laryngospasm require reintubation to maintain adequate oxygenation and ventilation. However, reintubation may be only a temporary solution because laryngospasm may recur during re-emergence and re-extubation; thus, anesthesiologists need a comprehensive plan that addresses potential causes of laryngospasm and incorporates continuous positive airway pressure (CPAP) for patients with difficulty emerging from GA. Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is a noninvasive ventilation and oxygenation technique used to provide apneic oxygenation, which also generates CPAP. THRIVE uses a high-flow nasal cannula and is more easily tolerated than CPAP with a tight-fitting mask. To our knowledge, we present the first case of refractory laryngospasm during emergence from GA that was successfully managed with THRIVE.

Bayesian predictive probabilities: a good way to monitor clinical trials.

BACKGROUND: Bayesian methods, with the predictive probability (PredP), allow multiple interim analyses with interim posterior probability (PostP) computation, without the need to correct for multiple looks at the data. The objective of this paper was to illustrate the use of PredP by simulating a sequential analysis of a clinical trial. METHODS: We used data from the Laryngobloc trial that planned to include 480 patients to demonstrate the equivalence of success between a laryngoscopy performed with the Laryngobloc® device and a control device. A crossover Bayesian design was used. The success rates of the two laryngoscopy devices were compared. Interim analyses, computed from random numbers of subjects, were simulated. RESULTS: The PostP of equivalence rapidly reached the predefined bound of 0.95. The PredP computed with an equivalence margin of 10% reached the efficacy bound between 352 and 409 of the 480 included patients. If a frequentist analysis had been made on the basis of 217 out of 480 subjects, the study would have been prematurely stopped for equivalence. The PredP indicated that this result was nonetheless unstable and that the equivalence was, thus far, not guaranteed. CONCLUSIONS: Based on these interim analyses, we can conclude with a sufficiently high probability that the equivalence would have been met on the primary outcome before the predetermined end of this particular trial. If a Bayesian approach using PredP had been used, it would have allowed an early termination of the trial by reducing the calculated sample size by 15-20%.

Theory and practical use of Bayesian methods in interpreting clinical trial data: a narrative review.

The critical reading of scientific articles is necessary for the daily practice of evidence-based medicine. Rigorous comprehension of statistical methods is essential, as reflected by the extensive use of statistics in the biomedical literature. In contrast to the customary frequentist approach, which never uses or gives the probability of a hypothesis, Bayesian theory uses probabilities for both hypotheses and data. This statistical approach is increasingly used for analyses of clinical trial data and for applied machine learning. The aim of this review is to compare general Bayesian concepts with frequentist methods to facilitate a better understanding of Bayesian theory for readers who are not familiar with this approach. The review is intended to be used in combination with a checklist we have devised for reading reports analysed by Bayesian methods. We compare and contrast the different approaches of Bayesian vs frequentist statistical methods by considering data from a clinical trial that lends itself to this comparative approach.

A consensus checklist to help clinicians interpret clinical trial results analysed by Bayesian methods.

INTRODUCTION: In the context of an increasing number of publications of trial data analysed by Bayesian methods, clinicians need support to better understand Bayesian statistical methods. The existing checklists are intended for people who already know these methods. We aimed to establish and validate a checklist that contains a group of items considered crucial in interpreting the results of a phase III RCT analysed with Bayesian methods. METHODS: A team of biostatisticians created a checklist of previously reported items and additional items identified from a literature review. Using three different articles in three rounds, the items were then validated by residents in anaesthesiology with no skills in statistics. RESULTS: Based on an initial item list, three rounds led to a consensus checklist. Eleven items were considered important information to be specified for understanding the validity of the results. Of these, three were considered essential: specification of the prior, source of the prior (when prior is informative), and the effect size point estimate with its credible interval. CONCLUSION: The checklist can help clinicians interpret the results of a phase III randomised clinical trial analysed by Bayesian methods, even clinicians with no particular knowledge of statistics, to ensure that the major elements of the statistical section are present and valid. Care should be taken in interpreting the results of a trial analysed by Bayesian methods that are not reported with these three essential items because the validity of the results cannot be established.

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.

Multicenter comparison of three intraoperative hemoglobin trend monitoring methods.

Transfusion decisions are guided by clinical factors and measured hemoglobin (Hb). Time required for blood sampling and analysis may cause Hb measurement to lag clinical conditions, thus continuous intraoperative Hb trend monitoring may provide useful information. This multicenter study was designed to compare three methods of determining intraoperative Hb changes (trend accuracy) to laboratory determined Hb changes. Adult surgical patients with planned arterial catheterization were studied. With each blood gas analysis performed, pulse cooximetry hemoglobin (SpHb) was recorded, and arterial blood Hb was measured by hematology (tHb), arterial blood gas cooximetry (ABGHb), and point of care (aHQHb) analyzers. Hb change was calculated and trend accuracy assessed by modified Bland-Altman analysis. Secondary measures included Hb measurement change direction agreement. Trend accuracy mean bias (95% limits of agreement; g/dl) for SpHb was 0.10 (- 1.14 to 1.35); for ABGHb was - 0.02 (- 1.06 to 1.02); and for aHQHb was 0.003 (- 0.95 to 0.95). Changes more than ± 0.5 g/dl agreed with tHb changes more than ± 0.25 g/dl in 94.2% (88.9-97.0%) SpHb changes, 98.9% (96.1-99.7%) ABGHb changes and 99.0% (96.4-99.7%) aHQHb changes. Sequential changes in SpHb, ABGHb and aHQHb exceeding ± 0.5 g/dl have similar agreement to the direction but not necessarily the magnitude of sequential tHb change. While Hb blood tests should continue to be used to inform transfusion decisions, intraoperative continuous noninvasive SpHb decreases more than - 0.5 g/dl could be a good indicator of the need to measure tHb.

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.