Virtual reality simulation as a training tool for perfusionists in extracorporeal circulation: Establishing face and content validity.

Objective: We conducted a prospective study to assess the face and content validity of a new virtual reality (VR) extracorporeal circulation simulator (ECC) developed for perfusionists to facilitate training and practice. We evaluated the opinions of students and staff members about the feasibility of the simulation. The 2 groups consisted of experts (qualified perfusionists) and novices (trainee perfusionists). Methods: Perfusionists (n = 12 experts and n = 11 trainees) received instructions on how to use the VR simulator and then proceeded to perform the start of cardiopulmonary bypass in the VR environment. Participants then completed a Usefulness, Satisfaction, and Ease of Use Questionnaire. The questions were rated on a 5-point Likert scale, ranging from 1 (fully disagree) to 5 (fully agree), to assess the face validity and content validity of this simulator. Results: Participants reported a predominantly positive experience with the VR-ECC simulator, with 96% (n = 22) agreeing that the simulator was a useful way of training ECC scenarios. All participants found it easy to interact with the software (100%, n = 23), and 82% of students (n = 9) believed it helped them remember the steps involved with initiating ECC. Finally, (87% [n = 20]) of participants believed the image quality and depth perception were good. Conclusions: Our next-generation simulator was valid for face and content constructs, and almost all participants found it to be a useful way of training for ECC scenarios. This simulator represents a first step toward truly blended digital learning and a new interactive, flexible, and innovative modality for perfusion training.

Potentially clinically relevant concentrations of Cefazolin, Midazolam, Propofol, and Sufentanil in auto-transfused blood in congenital cardiac surgery.

BACKGROUND: Use of donor blood in congenital cardiac surgery increases the risk for post-operative morbidity and mortality. To reduce the need for allogenic blood transfusion a technique for peri-operative mechanical red cell salvage is applied. Blood from the operation site is collected in a reservoir, processed, passed through a lipophilic filter and returned to the patient. Influence of this cellsaver system on coagulation, fibrinolysis and inflammatory markers is known. To our knowledge no studies have been performed on the effects of autotransfusion on drug concentrations. A clinically relevant drug dose could potentially be returned to the patient through the auto-transfused blood, leading to unwanted drug reactions post-operatively. We aimed to measure drug concentrations in blood salvaged from the operation site and in the auto-transfused blood to determine if a clinically relevant drug dose is returned to the patient. METHODS: The study was performed at the Department of Cardiothoracic Surgery of a tertiary university hospital. Blood samples were taken from the reservoir, after processing before the lipophilic filter, the auto-transfused blood, and the waste fluid. Samples were stored at - 80 C and drug concentration for sufentanil, propofol, midazolam and cefazolin were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Drug concentrations measured in the reservoir and the auto-transfused blood were compared and the relative reduction was calculated for each patient. RESULTS: Blood samples were taken from 18 cellsaver runs in 18 patients, age 0-13 years. Drug concentrations in the reservoir were comparable to concomitant concentrations in the patient. For sufentanil 34% (median, IQR 27-50) of drug concentration was retained from the reservoir in the auto-transfused blood, for midazolam 6% (median, IQR 4-10), for cefazolin 5% (median, IQR 2-6) and for propofol 0% (median, IQR 0-0) respectively. CONCLUSION: Depending on the drug, up to 34% of the drug concentration salvaged from the operation site is returned to the patient through autotransfusion, potentially causing unwanted drug reactions post-operatively. Additionally, influence of a cellsaver system should be considered in pharmacological research during and after congenital cardiac surgery and could result in dose adjustments in the postoperative phase. TRIAL REGISTRATION: Registration at the Dutch Trial Registry ( NTR3579 ) at August 14 2012.

Donor pretreatment with carbamylated erythropoietin in a brain death model reduces inflammation more effectively than erythropoietin while preserving renal function.

OBJECTIVE: We hypothesized that donor treatment of deceased brain dead donors would lead to a decrease in inflammatory responses seen in brain death and lead to a restoration of kidney function. DESIGN: A standardized slow-induction rat brain death model followed by evaluation of kidney function in an isolated perfused kidney model. SETTINGS: Surgery Research Laboratory, University Medical Center Groningen, the Netherlands. SUBJECTS: Male Fisher rats. INTERVENTIONS: Donor treatment with erythropoietin, carbamylated erythropoietin, which lacks erythropoietic activity, or vehicle. MEASUREMENTS AND MAIN RESULTS: In brain death, carbamylated erythropoietin and, to a lesser extent, erythropoietin were able to decrease the expression of several proinflammatory genes and to decrease the infiltration of polymorphonuclear cells in the kidney. No effect on tubular injury parameters was seen. Kidney function decreased almost by 50% after brain death but was fully restored after treatment with both carbamylated erythropoietin and erythropoietin. CONCLUSIONS: Carbamylated erythropoietin can inhibit the inflammatory response caused by brain death more effectively than erythropoietin, whereas both substances can restore kidney function after brain death.

The gradual onset brain death model: a relevant model to study organ donation and its consequences on the outcome after transplantation.

Organs used for transplantation are usually derived from heart-beating brain dead donors. However, brain death is known to have negative effects on donor organ quality, previously studied using a difficult to control sudden onset experimental model. We have now developed a reproducible gradual onset brain death model in rats without requiring inotropic support. Fisher inbred rats weighing 260-300 g were used. Brain death was induced by a gradual inflation of a subdurally placed balloon catheter. During induction and the period following brain death, the animals were mechanically ventilated and blood pressure was continuously monitored. The blood pressure registration showed a characteristic pattern during brain death induction, in which a decrease in blood pressure, a hypotensive period in which the Cushing response occurred, and a sharp peak were consistent findings. After brain death was induced, blood pressure was maintained at normotensive levels up to 4 h. After the experiments, neuropathological evaluation of the brain located haemorrhagic cerebral parenchyma, and immunocytochemistry of liver tissue revealed a significant influx of polymorph nuclear cells, as was previously observed as well. This improved model allows the study of brain death on donor organ quality without the use of inotropic support.