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.

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.

Intraoperative fluid restriction in hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Multiple studies highlight the importance of liberal fluid administration in cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Over-resuscitation can delay recovery and wound healing. We report an intraoperative protocol that restricts fluid administration and minimizes morbidity. MATERIALS AND METHODS: Retrospective analysis of 35 patients that underwent CRS-HIPEC for curative intent under fluid restriction protocol from June 2015 to July 2017 was performed. Protocol consists of continuous infusion of vasopressin 0.02 units/h and maintaining urine output at 0.5 mL/kg/h via crystalloid and colloid. Endpoint was Clavien-Dindo ≥3 events within 30 d of CRS-HIPEC. RESULTS: Median age was 56 y; 71% were female. Malignancies treated: appendix (49%), colon (31%), and other (20%). Median peritoneal cancer index was 15, complete cytoreduction was achieved in 91% of patients. Median time for return of bowel function was 5 d, median length of hospital stay was 7 d. There were 28 bowel anastomoses. Median intraoperative crystalloid, colloid, and packed red blood cells were (1900, 1500, and 700 mL), respectively. Clavien-Dindo grade 3-4 events occurred in five patients. There were no deaths 30 d after surgery. CONCLUSIONS: A fluid restriction protocol appears to be safe and feasible in the setting of CRS-HIPEC for curative intent.

Intracardiac thrombosis during liver transplant: A 17-year single-institution study.

Intracardiac thrombosis (ICT) during orthotopic liver transplantation (OLT) is an uncommon event. However, it is a devastating complication with high mortality when it occurs. This study aimed to identify possible predisposing factors for ICT during OLT. We retrospectively identified the cases of all patients with ICT during OLT at our institution from 1998 to 2014. Of 2750 OLTs performed, 10 patients had ICT intraoperatively. The patients' immediate prethrombosis intraoperative hemodynamic and coagulation values and thromboelastography (TEG) data were reviewed. Preexisting venous thrombosis, atrial fibrillation, and the prior placement of a transjugular intrahepatic portosystemic shunt for portal hypertension were noted in several patients and may be related to ICT during OLT. A high Model of End-Stage Liver Disease score, low cardiac output, and sepsis did not appear to be associated with ICT. ICT occurred in some patients without the administration of antifibrinolytic agents. TEG and coagulation parameters did not appear to be helpful in predicting the onset of ICT. Four patients had ICT in both right- and left-sided heart chambers; none of these 4 patients survived. All 6 patients with only right-sided thrombus survived. In those who survived, improved hemodynamics and clot disappearance on transesophageal echocardiography (TEE) occurred over time, even without the use of thrombolytics. Whether this is because of endogenous thrombolysis or distal clot propagation into the pulmonary vasculature, or both, is unclear. Tissue plasminogen activator may have a role in the resuscitation procedure. In conclusion, without the routine use of TEE during OLT, the incidence of ICT will remain an under-recognized event.

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.

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.

Is a mandatory intensive care unit stay needed after liver transplantation? Feasibility of fast-tracking to the surgical ward after liver transplantation.

The continuation of hemodynamic, respiratory, and metabolic support for a variable period after liver transplantation (LT) in the intensive care unit (ICU) is considered routine by many transplant programs. However, some LT recipients may be liberated from mechanical ventilation shortly after the discontinuation of anesthesia. These patients might be appropriately discharged from the postanesthesia care unit (PACU) to the surgical ward and bypass the ICU entirely. In 2002, our program started a fast-tracking program: select LT recipients are transferred from the operating room to the PACU for recovery and tracheal extubation with a subsequent transfer to the ward, and the ICU stay is completely eliminated. Between January 1, 2003 and December 31, 2007, 1045 patients underwent LT at our transplant program; 175 patients were excluded from the study. Five hundred twenty-three of the remaining 870 patients (60.10%) were fast-tracked to the surgical ward, and 347 (39.90%) were admitted to the ICU after LT. The failure rate after fast-tracking to the surgical ward was 1.90%. The groups were significantly different with respect to the recipient age, the raw Model for End-Stage Liver Disease (MELD) score at the time of LT, the recipient body mass index (BMI), the retransplantation status, the operative time, the warm ischemia time, and the intraoperative transfusion requirements. A multivariate logistic regression analysis revealed that the raw MELD score at the time of LT, the operative time, the intraoperative transfusion requirements, the recipient age, the recipient BMI, and the absence of hepatocellular cancer/cholangiocarcinoma were significant predictors of ICU admission. In conclusion, we are reporting the largest single-center experience demonstrating the feasibility of bypassing an ICU stay after LT.

Safe administration of hyperbaric oxygen after bleomycin: a case series of 15 patients.

INTRODUCTION: Supplemental oxygen has been reported to cause pulmonary complications after bleomycin. We describe the safe administration of hyperbaric oxygen (HBO2) after bleomycin in 15 patients. METHODS: Paper and electronic records were reviewed for bleomycin-exposed patients at the Duke Center for Hyperbaric Medicine and Environmental Physiology from 1979 to 2010. RESULTS: Fourteen bleomycin-exposed patients received HBO2 at Duke under a special-precautions protocol. One was treated for DCS elsewhere. The protocol included: pretreatment evaluation; chest radiograph; spirometry; blood gases; a single, 2-atmospheres absolute (atm abs), 120-minute HBO2 treatment; and a gradual acceleration over one week to a twice-daily schedule contingent on clinical and laboratory findings. Bleomycin indications were: head-and-neck squamous cell carcinomas (11), Hodgkin's lymphoma (2), other carcinomas (2). HBO2 indications were: osteoradionecrosis (10), soft-tissue radionecrosis (3), DCS (1) and a provocative oxygen toxicity test for a military aviator (1). Total bleomycin doses ranged from 40 to 225u/m2 (mean +/- SD, 105 +/- 57) given in conjunction with other chemotherapies and/or radiation. Radiation was 63.3 +/- 31.72 Gy (mean +/- SD), none to the chest with the exception of one patient treated for DCS elsewhere. Other chemotherapies included: vinblastine (11), methotrexate (11), CCNU (6) cisplatinum (7), dacarbazin (2), Adriamycin (1), and vincristine (1). Median age at time of HBO2 was 52 years (range 22-77). Median bleomycin-to-HBO2 latency was 34 months (range 1-279). Three patients received HBO2 within six months, and seven patients received HBO2 within two years of their last bleomycin exposure. There were no adverse pre-to-post HBO2 changes in: arterial blood gases, spirometry, chest radiograph findings or clinical reports. There were no persistent post-HBO2 pulmonary complications on follow-up. Post-HBO2 data were available for 40%, 53%, 87% and 100% of these parameters respectively. DISCUSSION: Bleomycin and oxygen can individually cause acute pulmonary toxicity. However, evidence for increased long-term susceptibility based on their synergy may be overstated.

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.

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.

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.

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.

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.

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.

[Fulminant hepatic failure after simultaneous kidney-pancreas transplantation: a case report]. / Insuficiência hepática fulminante após transplante simultâneo de rim­pâncreas: um relato de caso.

We describe an unusual case of hyperacute hepatic failure following general anesthesia in a patient receiving a simultaneous kidney-pancreas transplant. Despite an aggressive evaluation of structural, immunological, viral, and toxicological causes, a definitive cause could not be elucidated. The patient required a liver transplant and suffered a protracted hospital course. We discuss the potential causes of fulminant hepatic failure and the perioperative anesthesia management of her subsequent liver transplantation.