Seman, Mitchell T.

Introduction. Obesity is a common comorbidity seen in the perioperative setting and is associated with many diseases including cardiovascular disease and obstructive sleep apnea. Laparoscopic Roux-en-Y gastric bypass is the gold standard surgical treatment for patients whose weight is refractory to diet and exercise. Caring for these patients perioperatively presents unique challenges to anesthesiologists and is associated with an increased risk of adverse respiratory events. In our study, we hypothesize that a low-dose perioperative ketamine infusion will reduce opioid consumption and improve analgesia when compared to standard therapy. Methods. This is a single-center, prospective randomized controlled study enrolling 35 patients in total. Patients were randomized equally into the ketamine and control group. Preop, intraop, and postop management regimens were standardized. The ketamine group received a 0.3 mg/kg ideal body weight ketamine bolus after induction followed by a 0.2 mg/kg/hr ketamine infusion continued into the postop setting for up to 24 hours. Data collected included total perioperative opioids used converted to oral morphine equivalents (ME), pain scores, side effects, hospital length of stay, and patient satisfaction captured via postoperative questionnaires. Results. The use of perioperative opioid consumption was significantly lower in the ketamine group when compared with the control group (179.9 ME versus 248.7 ME, P = 0.03 ). There was no statistically significant difference in pain scores or hospital length of stay postoperatively between the two groups. There were also no reported adverse respiratory events, prolonged sedation, agitation, or other side effects reported in either group. The patient satisfaction questionnaires showed a significant difference with the ketamine group reporting lower maximum pain scores, a decrease in how pain limited activities of daily living once discharged, and increased hospital pain management satisfaction scores. Conclusions. Perioperative low-dose ketamine infusions significantly reduced opioid consumption in morbidly obese patients undergoing laparoscopic gastric bypass surgery.

Background. Utilization of intraoperative transesophageal echocardiography (TEE) during orthotopic liver transplantation (OLT) is expanding annually in high-volume transplant centers. During OLT intraoperative TEE is used to gather real-time information on cardiovascular function and intravascular volume status. Although standardized TEE views exist, there are nontraditional views described in the literature which have the potential to diagnose evolving pathology and define normal variants of hepatic vasculature. Methods. A literature review was completed utilizing the PubMed database for English-only, peer-reviewed publications discussing nontraditional use of intraoperative TEE during OLT and hepatic vascular-related surgeries from 2009 to 2019. Both case reports and review articles were considered. Results. The PubMed literature search offered 8 publications for analysis, including 7 case reports and 1 article review, revealing several nontraditional TEE views not included in a comprehensive transesophageal echocardiographic examination. These nontraditional views were generally obtained using modifications to the transgastric and bicaval views to visualize liver vasculature. We present the various techniques for obtaining these views from the 8 articles identified. Conclusions. At high-volume transplant centers, TEE use during OLT is increasing. Intraoperative TEE is a valuable tool to assess hepatic vascular structures critical to allograft/organ function without interruption of the surgical procedure. Nontraditional use of TEE to diagnose intraoperative noncardiac pathology in OLT appears underutilized and underreported. The modified hepatic and modified transgastric views we describe can be used to evaluate hepatic vasculature, influence surgical decision-making and ultimately improve patient care.

Intraoperative Transesophageal Echocardiography (TEE) during orthotopic liver transplant (OLT) is used to gather real-time information on cardiovascular function and intravascular volume status. We report a case where nonstandard TEE views were used to inspect the hepatic vasculature after allograft implantation. A 29-year-old male with secondary biliary cirrhosis with a MELD score of 20 underwent OLT using a liver from a 21-year-old brain-dead donor. Postreperfusion TEE, using the modified hepatic vein views, confirmed the presence of an inferior vena cava (IVC) suprahepatic anastomotic stenosis and hepatic vein and IVC thrombus resulting in hepatic venous outflow obstruction, allograft congestion, and hemodynamic instability. These nonstandard TEE images established the extent of suprahepatic caval outflow obstruction, in which intraoperative ultrasound was unable to definitively demonstrate. This guided real-time surgical decision-making in the postimplantation phase of the operation—ultimately leading to hepatic vein and IVC thrombectomy and revision of suprahepatic caval anastomosis.