Using Digital Biomarkers for Objective Assessment of Perfusionists' Workload and Acute Stress During Cardiac Surgery.

The cardiac operating room (OR) is a high-risk, high-stakes environment inserted into a complex socio-technical healthcare system. During cardiopulmonary bypass (CPB), the most critical phase of cardiac surgery, the perfusionist has a crucial role within the interprofessional OR team, being responsible for optimizing patient perfusion while coordinating other tasks with the surgeon, anesthesiologist, and nurses. The aim of this study was to investigate objective digital biomarkers of perfusionists' workload and stress derived from heart rate variability (HRV) metrics captured via a wearable physiological sensor in a real cardiac OR.

Using machine learning to predict perfusionists' critical decision-making during cardiac surgery.

The cardiac surgery operating room is a high-risk and complex environment in which multiple experts work as a team to provide safe and excellent care to patients. During the cardiopulmonary bypass phase of cardiac surgery, critical decisions need to be made and the perfusionists play a crucial role in assessing available information and taking a certain course of action. In this paper, we report the findings of a simulation-based study using machine learning to build predictive models of perfusionists' decision-making during critical situations in the operating room (OR).

Fraction of expired oxygen: an additional safety approach to monitor oxygen delivery to the heart lung machine oxygenator.

Background: Monitoring oxygen delivery to the oxygenator of a heart lung machine (HLM) is typically accomplished with an O analyzer connected to the gas inflow line. It is assumed when the FiO is greater than 21% that oxygen is being delivered to the oxygenator. However, this assumption is imperfect because the connection of the inflow line to the oxygenator is downstream from the O analyzer.

Analysis of Dynamic Changes in Cognitive Workload During Cardiac Surgery Perfusionists' Interactions With the Cardiopulmonary Bypass Pump.

Objective: This novel preliminary study sought to capture dynamic changes in heart rate variability (HRV) as a proxy for cognitive workload among perfusionists while operating the cardiopulmonary bypass (CPB) pump during real-life cardiac surgery.

Background: Estimations of operators' cognitive workload states in naturalistic settings have been derived using noninvasive psychophysiological measures. Effective CPB pump operation by perfusionists is critical in maintaining the patient's homeostasis during open-heart surgery.

Sensors for Continuous Monitoring of Surgeon's Cognitive Workload in the Cardiac Operating Room.

Monitoring healthcare providers' cognitive workload during surgical procedures can provide insight into the dynamic changes of mental states that may affect patient clinical outcomes. The role of cognitive factors influencing both technical and non-technical skill are increasingly being recognized, especially as the opportunities to unobtrusively collect accurate and sensitive data are improving. Applying sensors to capture these data in a complex real-world setting such as the cardiac surgery operating room, however, is accompanied by myriad social, physical, and procedural constraints.

A Quick Reference Tool for Goal-Directed Perfusion in Cardiac Surgery.

Traditionally, blood flow rates on cardiopulmonary bypass are based primarily on a formula that matches cardiac index to the patient's body surface area (BSA). However, Ranucci and associates in the Goal-Directed Perfusion Trial (GIFT) trial have shown that coupling the BSA with delivery of oxygen (DO), known as goal-directed perfusion (GDP), may be a safer approach to determine appropriate blood flows. The objective of this study was to create a GDP reference tool that would allow perfusionists to quickly determine the lowest acceptable blood flow needed to provide a patient of any BSA with a satisfactory DO without the need for additional dedicated technology.

Establishing a Ventilator-Heart Lung Machine Communication Bridge to Mitigate Errors when Weaning from Bypass.

If a perfusionist weans a patient off the heart lung machine (HLM) and the anesthesiologist has not re-started the ventilator, the patient will become hypoxic. The objective of this project was to create a redundant safety system of verbal and electronic communication to prevent failure to ventilate errors after cardiopulmonary bypass. This objective could be realized by building an electronic communication bridge directly between the HLM and ventilator.

Hemoglobinopathies and stroke: strategies for prevention and treatment.

Current treatment options for stroke in sickle cell disease (SCD) and thalassemia are limited. Hypercoagulation occurs in both diseases partly due to activated platelets and red blood cell dysmorphology and dysfunction, resulting in chronic anemia. This overlapping pathophysiology of the nervous system promotes the role of some common treatment modalities for these similar diseases.

Evaluation of blood components exposed to coated arterial filters in extracorporeal circuits.

Background: Biocompatible surfaces play an important role in the inflammatory response during cardiopulmonary bypass (CBP), with the arterial filter contributing a large surface area of the circuit. Different filter-coating materials designed to improve blood-filter biocompatibility are currently used in CPB circuits. This study evaluates eight biocompatible coatings used for arterial filters and their effects on blood components during circulation.

Expired liquid preserved platelet releasates retain proliferative activity.

Background: Donated platelets for clinical use currently have a shelf life of 5 days as the result of possible bacterial contamination and loss of hemostatic function. Platelet releasates contain multiple growth factors that have been shown to accelerate wound healing. We sought to demonstrate that although expired platelets can no longer sustain hemostasis, they serve a longer term role as a reservoir of growth factors that could be harnessed in wound healing applications.

In vitro effects of poly-N-acetyl glucosamine on the activation of platelets in platelet-rich plasma with and without red blood cells.

Background: This study was performed to assess the effect of poly-N-acetyl glucosamine fiber slurry on plasma clotting proteins, platelets, and red blood cells in the clotting of the blood.

Methods: Citrate phosphate dextrose whole blood was stored at 22degreesC for 48 hours to prepare platelet-poor plasma, platelet-rich plasma (PRP), and PRP plus red blood cells with hematocrit values of 20%, 35%, and 45% with and without an equal volume of poly-N-acetyl glucosamine fibers (1 mg/mL 0.9% NaCl).

The in vitro quality of red blood cells frozen with 40 percent (wt/vol) glycerol at -80 degrees C for 14 years, deglycerolized with the Haemonetics ACP 215, and stored at 4 degrees C in additive solution-1 or additive solution-3 for up to 3 weeks.

Background: Red blood cells (RBCs) frozen with 40 percent (wt/vol) glycerol, stored at -80 degrees C (mean temperature; range, -65 to -90 degrees C) for 14 years, deglycerolized in the Haemonetics automated cell processor (ACP) 215 with the 325-mL disposable bowl, and stored at 4 degrees C in additive solution (AS)-1 or AS-3 for 21 days were evaluated.

Study Design And Methods: A total of 106 units of citrate phosphate dextrose adenine-1 RBCs were frozen with 40 percent (wt/vol) glycerol in the original 800-mL polyvinylchloride plastic bag and stored in corrugated cardboard boxes at -80 degrees C for 14 years. The thawed units were deglycerolized with the ACP 215 with a 325-mL disposable bowl and stored in AS-1 or AS-3 at 4 degrees C for 21 days.

Comparison of radioisotope methods and a nonradioisotope method to measure the RBC volume and RBC survival in the baboon.

Background: RBC volume, 24-hour posttransfusion survival, and life span can be measured with radio-isotopes and nonradioactive procedures.

Study Design And Methods: RBC volume was measured directly with autologous baboon RBCs labeled with biotin-X-N-hydroxysuccinimide (NHS), 51Cr, 99mTc, and 111In-oxine and indirectly from the 125I plasma volume and the total body Hct. Twenty-four-hour posttransfusion survival and life span were measured in autologous fresh baboon RBCs labeled with 51Cr, 111In-oxine, 99mTc, and biotin-X-NHS.

Restoration of red blood cell volume following 2-unit red blood cell apheresis.

Background And Objectives: Blood donors who weigh at least 130 lbs (59 kg) and have a haematocrit of at least 40 V per cent can donate 2 units of blood, from which a 360-ml volume of red blood cells (RBC) can be isolated. This study was carried out in seven healthy male blood donors to assess the restoration of the RBC volume 1 month following a 2-unit RBC apheresis procedure.

Materials And Methods: RBC volumes were measured prior to donation and 4 weeks after the 2-unit RBC apheresis procedure without oral iron supplementation.

Effect of WBC reduction and storage temperature on PLTs frozen with 6 percent DMSO for as long as 3 years.

Background: PLTs frozen with 6 percent DMSO can be stored at -80 degrees C for 2 years, while those frozen with 5 percent DMSO at -150 degrees C can be stored for at least 3 years. The more rapid deterioration seen in PLTs frozen at -80 degrees C may be due to the presence of granulocytes. The effects of storage temperature and WBC reduction on PLTs frozen with DMSO and the breakage of the PVC plastic bags stored at -80 and -135 degrees C were assessed.

Incidence of breakage of human RBCs frozen with 40-percent wt/vol glycerol using two different methods for storage at -80 degrees C.

Background: We reported previously that the incidence of breakage was 34.2 percent when human RBCs were frozen with 40-percent wt/vol glycerol in polyolefin plastic bags stored in aluminum containers at -80 degrees C and subjected to transportation. When human RBCs were frozen with 40-percent wt/vol glycerol at -80 degrees C in PVC plastic bags placed in polyester plastic bags and stored in rigid corrugated cardboard boxes, transportation resulted in a 2.

A multicenter study of in vitro and in vivo values in human RBCs frozen with 40-percent (wt/vol) glycerol and stored after deglycerolization for 15 days at 4 degrees C in AS-3: assessment of RBC processing in the ACP 215.

Background: The FDA has approved the storage of frozen RBCs at -80 degrees C for 10 years. After deglycerolization, the RBCs can be stored at 4 degrees C for no more than 24 hours, because open systems are currently being used. Five laboratories have been evaluating an automated, functionally closed system (ACP 215, Haemonetics) for both the glycerolization and deglycerolization processes.

An experiment with glycerol-frozen red blood cells stored at -80 degrees C for up to 37 years.

Background And Objectives: Red cells frozen using 40% W/V glycerol are currently FDA approved for frozen storage at -80 degrees C for up to 10 years.

Materials And Methods: Red cells frozen with 40% W/V glycerol and stored at -80 degrees C for up to 37 years were thawed, deglycerolized, and stored at 4 degrees C for 24 h.

Results: Red cells frozen for up to 37 years had mean freeze-thaw-wash recovery values of 75%, less than 1% hemolysis, and normal ATP, 2,3-DPG and P50 levels, and 60% of normal RBC K(+) levels.