Caleb Weber
Pronouns: he/him
Research Mentor(s): Alvaro Rojas-Peña
Research Mentor School/College/Department: Department of Surgery-Transplantation / Medicine
Program: UROP
Session: Session 1 (9:00am – 9:50am)
Authors: Jack Davis, Caleb Weber, Daniela Pelaez Palacio, Jamie Ho, Jensyn VanZalen, Robert H. Bartlett, Brianna Specner, Alvaro Rojas-Pena
Abstract
Background: Extracorporeal life support (ECLS) is used for acute and chronic cardio-respiratory management of patients. To study novel ECLS applications such as anticoagulation protocols and the artificial lung, large animal models with complex anesthesia management and surgical procedures are required. A review of clinical records was performed to identify intraoperative factors associated with complications during ECLS testing in sheep. Methods: A retrospective study of sheep clinical records from February to May 2022 at the UM-ECLS laboratory of the artificial lung (AL-group) and local surface anticoagulation (LSA-group) projects was done. Inclusion criteria: records of successful surgical procedures with recovery to the chronic room. Excluded criteria: duplicate and incomplete records. Data analyzed: heart rate (HR), blood pressure (BP), P/F ratio (partial pressure of O2/FiO2), and lactate. All variables were evaluated intraoperative for 4 hours. Data is presented as means and standard deviation. Results: Seventeen records were analyzed. Seven sheep were excluded in accordance with exclusion criteria (records from non-recovery studies (5), duplicate records (1), and early intraoperative death (1). Sheep in the LSA-group were 48.75±4.7 kg while sheep in the AL-group were 14.3±4 kg. HR was within normal values (80-110 bpm) in both groups but increased towards the end of surgery (LSA-group= 115±16 bpm and AL-group= 143±17 bpm). BP in the LSA-group was normal (mean >70 mmHg) and hypotension (mean <60 mmHg) was observed in the AL-group requiring vasopressor agents and/or iv fluid bolus. The P/F ratio was normal in the LSA-group (485-590). In the AL-group P/F ratio oscillated between 250-700 due to lung compression. Lactate was normal (0.85-1.3 mmol/L) in the LSA-group, while hyperlactatemia (2.06±1.50 mmol/L) was observed at the end of surgery in the AL-group. Conclusion: Intraoperative hypotension with vasopressor support and hyperlactatemia correlated with postoperative complications (bleeding and oxygen dependency) in the AL-group. Heart rate and P/F ratio do not show predictive value. Larger scale studies should be completed to further determine association. Keywords: Extracorporeal life support (ECLS); mortality; predictor; animal models; ovine.
