Torp, Klaus D.

Abstract Rationale Transthoracic echocardiography (TTE) is a very useful measure of cardiac function in patients with pulmonary hypertension (PH), along with right heart catheterization, which is considered to be the gold standard of measurement. It is non-invasive, quick and a good screening tool to assess the function of a failing right ventricle against elevated pulmonary pressures. Portopulmonary hypertension (POPH) is defined as PH associated with portal hypertension. The Tricuspid Annular Plane Systolic Excursion to Systolic Pulmonary Artery Pressure (TAPSE/SPAP) ratio has been found to be an effective prognosticator in different subtypes of PH. This study focuses on the role of TAPSE/SPAP ratio in prognosis of patients with POPH undergoing liver transplantation. Methods This was a single-center retrospective study of POPH patients undergoing liver transplantation at Mayo Clinic Florida from June 2003 to December 2023. It included patients with POPH with a mean pulmonary pressure >20 mm Hg undergoing liver transplantation. Patients with incomplete TTE data, coexisting renal failure on dialysis and requiring liver retransplant were excluded. This study included 27 patients. The last TTE report before liver transplantation was used for data analysis. The TAPSE/SPAP ratio was investigated as predictor of all-cause mortality following liver transplant using Cox regression and area under ROC curve. (Brackets contain 95% C.I.) Time to death after liver transplantation was considered. Patients were followed till August 1, 2024. (The correlation of this ratio-TAPSE/SPAP with some catheterization measured pulmonary pressures and indices have been included in Table 1.) Results Among 27 patients, 13 were female, 14 male. The most common causes of liver failure in these patients were non alcoholic fatty liver disease (NASH) and alcoholic liver disease. Rarely, some etiologies like sarcoidosis, autoimmune hepatitis, primary sclerosing cholangitis and hepatitis B/C were present. There were 7 deaths among total of 27 patients. The hazard ratio (HR) of TAPSE/SPAP for overall mortality by Cox regression was 0.01 (0.00-0.58), p = 0.03. The area under ROC curve was 0.76 (0.55-0.96), p = 0.01 [Also for TAPSE alone, the area under ROC curve was 0.74 (0.51-0.97), p = 0.05] Conclusion This study infers that TAPSE/SPAP ratio seems to be a good predictor of survival in POPH patients undergoing liver transplant, with a higher ratio associated with decreased all-cause mortality. It suggests that TAPSE alone might also be a good predictor with higher TAPSE associated with decreased mortality. This abstract is funded by: None

AbstractIntroductionFor 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.MethodsWe 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.ResultsOne 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.ConclusionImmediate 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.

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.

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.

Phenylephrine is generally regarded as a “pure” α1-agonist. However, after treatment of the forearm with the α-adrenergic-blocking drug phentolamine, brachial artery infusion of phenylephrine can cause transient forearm vasodilation. To determine whether this response was β-receptor mediated, phenylephrine, phentolamine, and propranolol were infused into the brachial arteries of six healthy volunteers. Forearm vascular conductance (FVC) was also calculated and expressed as arbitrary units (units). Infusion of phenylephrine by itself (0.5 μg · dl forearm volume−1 · min−1) caused a sustained decrease ( P < 0.05) in FVC from 3.5 ± 0.7 to 0.9 ± 0.2 units ( P < 0.05). Infusion of the α-blocker phentolamine increased ( P < 0.05) baseline FVC to 5.7 ± 1.3 units. Subsequent infusion of phenylephrine after α-blockade caused FVC to increase ( P < 0.05) for ∼1 min from 5.7 ± 1.3 to a peak of 13.1 ± 1.8 units. Propranolol had no effect on baseline flow, and subsequent phenylephrine infusion after α- and β-blockade caused a small, but significant, sustained decrease in FVC from 5.1 ± 1.0 to 3.6 ± 0.8 units. There were no systemic effects from the infusions, and saline infusion at the same rate (1–2 ml/min) had no forearm vasoconstrictor or dilator effects. These data indicate that in humans phenylephrine can exert transient β2-vasodilator activity when its predominant α-constrictor effects are blocked.

AbstractIntroductionTakotsubo syndrome (TTS), also known as Takotsubo cardiomyopathy or stress‐induced cardiomyopathy, has been described following a variety of surgeries and disease states. The relationship between intra‐operative anesthesia management and the development of this syndrome has never been fully elucidated.ObjectivesThe primary objective of this study was to determine the relationship of multiple intra‐operative factors on the pathogenesis of TTS.MethodsA single‐center retrospective review of all liver transplants performed at Mayo Clinic Florida from January 2005 to December 2014. Patients developing left ventricular dilation and a concomitant decrease in ejection fraction, a negative cardiac catheterization, or stress test within 30 days of transplantation were identified. Cases were matched 2:1 to controls with respect to MELD, age, sex, and indication for transplantation. Our evaluation included liver graft characteristics, intra‐operative medications, and intra‐operative hemodynamic measurements.ResultsWe identified 24 cases of TTS from a pool of 1752 transplants, for an incidence of 1.4%. No statistically significant differences in intra‐operative measures between the two groups were identified (all P ≥ .08).ConclusionOur exploratory, single‐center retrospective review evaluating 46 intra‐operative characteristics found no association with the development of TTS.