Design of a cost-effective, hemodynamically adjustable model for resuscitative endovascular balloon occlusion of the aorta (REBOA) simulation.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct technique for salvaging patients with noncompressible torso hemorrhage. Current REBOA training paradigms require large animals, virtual reality simulators, or human cadavers for acquisition of skills. These training strategies are expensive and resource intensive, which may prevent widespread dissemination of REBOA. We have developed a low-cost, near-physiologic, pulsatile REBOA simulator by connecting an anatomic vascular circuit constructed out of latex and polyvinyl chloride tubing to a commercially available pump. This pulsatile simulator is capable of generating cardiac outputs ranging from 1.7 to 6.8 L/min with corresponding arterial blood pressures of 54 to 226/14 to 121 mmHg. The simulator accommodates a 12 French introducer sheath and a CODA balloon catheter. Upon balloon inflation, the arterial waveform distal to the occlusion flattens, distal pulsation within the simulator is lost, and systolic blood pressures proximal to the balloon catheter increase by up to 62 mmHg. Further development and validation of this simulator will allow for refinement, reduction, and replacement of large animal models, costly virtual reality simulators, and perfused cadavers for training purposes. This will ultimately facilitate the low-cost, high-fidelity REBOA simulation needed for the widespread dissemination of this life-saving technique.

Randomized controlled trial comparing dynamic simulation with static simulation in trauma.

BACKGROUND: Current general surgery residents have limited exposure to open trauma operative cases. Simulation supplements variable rotation volume and provides experience with critical but rarely performed procedures. Open simulation classically focuses on static models with anatomic accuracy but lacks practicality when hemorrhage control is the lifesaving maneuver. We sought to evaluate whether training on a dynamic simulator, while much less expensive than training on a static cadaver, might be at least as effective in training surgery residents to expeditiously place temporary vascular shunts (TVSs). METHODS: Our research team developed an inexpensive, reusable dynamic simulator with ongoing hemorrhage to instruct trainees in the steps of TVS placement. We enrolled 54 general surgery residents in a noninferiority randomized controlled trial comparing training of TVS placement on the dynamic simulator (n = 28) versus a cadaver arm (n = 26). After standardized video didactics, trainees practiced on either the simulator or cadaver arm. After the trainees achieved competency, they were tested on placing a TVS for a live swine femoral artery injury. Two blinded trauma surgeons evaluated the recorded performances. RESULTS: Residents did not differ in baseline characteristics between groups, and all residents in both groups successfully completed the TVS placement test. Subjects trained on the simulator placed the TVS faster than those trained on a cadaver (584 seconds vs. 751 seconds; difference, +167 seconds faster; 90% confidence interval [CI], +52 to +282 seconds), with a trend toward faster time to hemorrhage control (110 seconds vs. 148 seconds; difference, +38 seconds faster; 90% CI, -8 to +84). There was no significant difference in Objective Structured Assessment of Technical Skills scores (3.72 vs. 3.44; difference, +0.27 units better; 90% CI, -0.04 to +0.59). CONCLUSION: Training on a dynamic simulator resulted in noninferior time to completion of vascular shunt placement compared with training on a cadaver. The addition of dynamic hemorrhage to simulators might inexpensively augment trauma skills training.

Prospective observational study of point-of-care creatinine in trauma.

BACKGROUND: Patients with trauma are at risk for renal dysfunction from hypovolemia or urological injury. In austere environments, creatinine values are not available to guide resuscitation. A new portable device, the Stat Sensor Point-of-care (POC) Whole Blood Creatinine Analyzer, provides accurate results in <30 s and requires minimal training. This device has not been evaluated in trauma despite the theoretical benefit it provides. The purpose of this study is to determine the clinical impact of the POC device in trauma. METHODS: 40 patients with trauma were enrolled in a prospective observational study. One drop of blood was used for creatinine determination on the Statsensor POC device. POC creatinine results were compared to the laboratory. Turnaround time (TAT) for POC and laboratory methods was calculated as well as time elapsed to CT scan if applicable. RESULTS: Patients (n=40) were enrolled between December 2014 and March 2015. POC creatinine values were similar to laboratory methods with a mean bias of 0.075±0.27 (p=0.08). Mean analytical TATs for the POC measurements were significantly faster than the laboratory method (11.6±10.0 min vs 78.1±27.9 min, n=40, p<0.0001). Mean elapsed time before arrival at the CT scanner was 52.9±34.2 min. CONCLUSIONS: The POC device reported similar creatinine values to the laboratory and provided significantly faster results. POC creatinine testing is a promising development for trauma practice in austere environments and workup of a subset of stable patients with trauma. Further study is warranted to determine clinical impact, both in hospital-based trauma and austere environments.

Can the Kawashima procedure be performed in younger patients?

BACKGROUND: The prudence of performing early palliative cavopulmonary connection that includes superior vena cava in association with azygous-hemiazygous continuation of the inferior vena cava, Kawashima procedure (KP), has been questioned. We document our experience with KP performed at a relatively younger age than usually reported. METHODS: A retrospective review of patients undergoing KP (October 2000 to April 2008) was done. RESULTS: Initial palliation was carried out in 13 of 15 patients. Age and weight at KP was 8.4 months (5.1 to 15.1) and 6.8 kg (4.6 to 11.0). The pre-KP catheterization showed the following: pulmonary artery pressure = 14.5 mm Hg (9 to 17); end-diastolic pressure of systemic ventricle = 8 (2 to 14); oxygenation saturation = 76% (63 to 82); and atrioventricular (AV) valve insufficiency moderate or greater in 5 patients. The post-KP characteristics included the following intubation = 1 day (0 to 19); nitric oxide = 4 patients; superior caval pressure = 14 mm Hg (6 to 18); inotrope score = 7.5 (2.5 to 14.3); intensive care unit stay = 3 days (1 to 9); hospital stay = 7 days (3 to 77); and oxygen saturation at discharge = 84% (76 to 90%). There was one hospital death that required takedown of KP. Fontan completion was performed in 8 patients at an interval of 2.7 years (1.8 to 5.8) after KP. There was one post-Fontan mortality from severe ventricular and AV valve dysfunction. Pulmonary arteriovenous malformations (PAVMs) were diagnosed in 4 patients with 3 resolving post-Fontan. With a median follow-up of 4.2 years (0.1 to 7.9), 13 of 15 remain alive yielding a series survival of 87%. CONCLUSIONS: The Kawashima procedure can be safely performed at an earlier age than previously reported. The incidence of PAVMs after the KP appears to be similar to other reports where KP was performed at a later age.