Extracorporeal Membrane Oxygenation in the Emergency Department

A New Multifunction Oxygenator With a Dual-Chamber Gas Exchanger to Reduce Dependence on Oxygen Supply

Although extracorporeal membrane oxygenation (ECMO) systems have been used to provide temporary support for patients with severe respiratory or cardiac failure, they are often bedridden, in part because of their bulky size which relies solely on an unlimited source of wall oxygen. However, there is an unmet clinical need for ambulatory ECMO which necessitates downsizing the ECMO system. We sought to develop a new oxygenator to reduce the dependence on the oxygen supply source. The proposed oxygenator features a dual-chamber gas exchangers, with one chamber primarily responsible for carbon dioxide removal using ambient air and a subsequent chamber primarily responsible for oxygen transfer using pure oxygen. Computational fluid dynamics was used to analyze the blood flow field to avoid adverse stagnation and optimize gas exchange performance. Bovine blood was used for in vitro gas transfer test. This new oxygenator demonstrated the capability to provide adequate respiratory support (both carbon dioxide removal and oxygen transfer) to adult patients at blood rate of 4-6 L/min with an oxygen supply of only 2 L/min. The reduced use of oxygen with this new oxygenator may pave the way for the development of potable ECMO systems.

Efficacy of a Single Day Extracorporeal Membrane Oxygenation Training Course for Critical Care Air Transport Team Eligible Personnel

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is an advanced medical technology that is used to treat respiratory and heart failure. The U.S. military has used ECMO in the care of combat casualties during Operation Enduring Freedom and Operation Iraqi Freedom as well as in the treatment of patients during the recent Coronavirus Disease 2019 pandemic. However, few Military Health System personnel have training and experience in the use of ECMO therapy. To address this dearth of expertise, we developed and evaluated an accelerated ECMO course for military medical personnel.

OBJECTIVES

To compare the efficacy of an accelerated ECMO course for Military Health System critical care teams.

METHODS

Seventeen teams, each consisting of a physician and nurse, underwent a 5-h accelerated ECMO course. Similar to our previous live-tissue ECMO training program (phases I and II), each team watched prerecorded ECMO training lectures. Subjects then practiced priming the ECMO circuit, cannulating ECMO, initiating ECMO, and correcting common complications on an ECMO simulation model. An added component to this phase III project included transportation and telemedicine consultation availability. Training success was evaluated via knowledge and confidence assessments, and observation of each team attempting to initiate ECMO on a Yorkshire swine patient model, transport the patient model, and troubleshoot complications with the support of telemedicine consultation when desired.

RESULTS

Seventeen teams successfully completed the course. All seventeen teams (100%) successfully placed the swine on veno-arterial ECMO. Of those, 15 teams successfully transitioned to veno-arterial-venous ECMO. The knowledge assessments of physicians and nurses increased by 12.2% from pretest (mean of 62.1%, SD 10.4%) to posttest (mean of 74.4%, SD 8.2%), P < .0001; their confidence assessments increased by 41.1% from pretest (mean of 20.1%, SD 11.8%) to posttest (mean of 61.2%, SD 18.6%).

CONCLUSIONS

An abbreviated 1-day lecture and hands-on task-trainer-based ECMO course resulted in a high rate of successful skill demonstration and improvement of physicians' and nurses' knowledge assessments and confidence levels, similar to our previous live-tissue training program. When compared to our previous studies, the addition of telemedicine and patient transportation to this study did not affect the duration or performance of procedures.

[Development and Evaluation of Evidence-Based Nursing Protocol for Extracorporeal Membrane Oxygenation to Critically Ill Patients]

PURPOSE

This study aimed to develop an evidence-based extracorporeal membrane oxygenation (ECMO) nursing protocol for critically ill patients receiving ECMO treatment by using an adaptation process, and to verify the effects of the protocol.

METHODS

The protocol was developed according to the adaptation guidelines. A non-randomized controlled trial was conducted to test the protocol's effects. Data were collected between April 2019 and March 2021. The differences in physiological indicators and complication rates between the two groups were investigated using a chart review to evaluate patient outcomes. The nurses' outcome variables were evaluated using a questionnaire.

RESULTS

First, after reviewing 11 guidelines by appraisal of the guidelines for research and evaluation collaboration II, 5 guidelines with a standardization grade of over 50 points were selected. An ECMO nursing protocol was developed based on these guidelines. Second, there were no statistically significant differences in physiological indicators between the two groups of patients. However, the experimental group showed a statistically significant decrease in the infection rate (p = .026) and pressure injury rates (p = .041). The levels of satisfaction with ECMO nursing care, and empowerment and performance of the nurses who used the ECMO nursing protocol were higher than those of nurses who did not (p < .001).

CONCLUSION

This protocol may help prevent infections and pressure injuries in patients, and improve nurses' satisfaction and empowerment. The nursing protocol developed for critically ill patients receiving ECMO treatment can be utilized in evidence-based nursing practice.

Efficacy of a single-day task trainer-based extracorporeal membrane oxygenation training course

Background

Extracorporeal membrane oxygenation (ECMO) is an advanced medical technology used to treat respiratory and heart failure. The coronavirus pandemic has resulted in significantly more ECMO patients worldwide. However, the number of hospitals with ECMO capabilities and ECMO-trained staff are limited. Training of personnel in ECMO could supplement this demand.

Objective

To evaluate our previously developed ECMO course using a task trainer-based training, as opposed to an existing live tissue-training model, and determine if such a program was adequate and could be expanded to other facilities.

Methods

Seventeen teams, each consisting of a physician and nurse, underwent a 5 hour accelerated ECMO course in which they watched prerecorded ECMO training lectures, primed circuit, cannulated, initiated ECMO, and corrected common complications. Training success was evaluated via knowledge and confidence assessments and observation of each team attempting to initiate ECMO while troubleshooting complications on a Yorkshire swine.

Results

Seventeen teams successfully completed the course. Sixteen teams (94%, 95% CI = 71%-100%) successfully placed the swine on veno-arterial ECMO. Of those 16 teams, 15 successfully transitioned to veno-arterial-venous ECMO. The knowledge assessments and confidence levels of physicians and nurses increased by 24.3% from pretest (mean of 65.3%, SD 14.4%) to posttest (mean of 89.6%, SD 10.3%), p < 0.0001.

Conclusions

An abbreviated one day lecture and hands-on task trainer-based ECMO course resulted in a high rate of successful skill demonstration and improvement of physicians' and nurses' knowledge assessments and confidence levels, similar to our previous live tissue training program.

Impact of Initial Operative Urgency on Short-Term Outcomes in Patients Treated with ECMO Due to Postcardiotomy Cardiogenic Shock

The outcomes of patients with PCS and following ECMO therapy are associated with several preoperative risk factors. Our aim was to compare clinical presentation, ECMO-related data and in-hospital outcomes of patients treated with ECMO due to PCS after cardiac surgery, in regard to elective or emergent cardiac surgery procedures. Between April 2006 and October 2016, 164 consecutive patients that received VA-ECMO therapy due to PCS were identified and included in this retrospective cohort study. The patients were divided into groups based on the urgency of the initial procedures performed: elective group (ELG; n = 95) and an emergency group (EMG; n = 69). To compare the unequal patient groups, a propensity score-based matching (PSM) was applied (ELG, n = 56 vs. EMG, n = 56). The EMG primarily received ECMO intraoperatively (p ≤ 0.001). In contrast, the ELG were needed ECMO support more frequently postoperatively (p < 0.001). In-hospital mortality accounted for 71% (n = 40) in the ELG and 76% (n = 43) in the EMG (p = 0.518). Outcome data showed no major differences in the (abdominal ischemia (p = 0.371); septic shock (p = 0.393): rhythm disturbances (p = 0.575); emergency re-thoracotomy (p = 0.418)) between the groups. The urgency of the initial procedures performed is secondary in patients suffering PCS and following ECMO. In this regard, PCS itself seems to trigger outcomes in cardiac surgery ECMO patients substantially.

A Parametric Analysis of Capillary Height in Single-Layer, Small-Scale Microfluidic Artificial Lungs

Microfluidic artificial lungs (μALs) are being investigated for their ability to closely mimic the size scale and cellular environment of natural lungs. Researchers have developed μALs with small artificial capillary diameters (10-50 µm; to increase gas exchange efficiency) and with large capillary diameters (~100 µm; to simplify design and construction). However, no study has directly investigated the impact of capillary height on μAL properties. Here, we use Murray's law and the Hagen-Poiseuille equation to design single-layer, small-scale μALs with capillary heights between 10 and 100 µm. Each µAL contained two blood channel types: capillaries for gas exchange; and distribution channels for delivering blood to/from capillaries. Three designs with capillary heights of 30, 60, and 100 µm were chosen for further modeling, implementation and testing with blood. Flow simulations were used to validate and ensure equal pressures. Designs were fabricated using soft lithography. Gas exchange and pressure drop were tested using whole bovine blood. All three designs exhibited similar pressure drops and gas exchange; however, the μAL with 60 µm tall capillaries had a significantly higher wall shear rate (although physiologic), smaller priming volume and smaller total blood contacting surface area than the 30 and 100 µm designs. Future μAL designs may need to consider the impact of capillary height when optimizing performance.

Successful treatment of severe electrolyte imbalance-induced cardiac arrest caused by adrenal tuberculosis with ECMO in the ED

Background

Tuberculosis (TB) is a chronic infectious disease, common in China. TB bacteria can invade multiple organs throughout the body, but they rarely cause critical illness. We present a complex critically ill case in this report.

Case presentation

A 40-year-old man suffered sudden cardiac arrest during an emergency room visit. Spontaneous circulation resumed after emergency cardiopulmonary resuscitation (CPR), but recurrent ventricular fibrillation and refractory cardiac shock emerged. Thereafter, extracorporeal membrane oxygenation (ECMO) was implemented to maintain hemodynamic stability. Blood test results revealed that the patient had severe electrolyte imbalance and adrenal insufficiency. Further imaging examination showed multiple tuberculosis lesions throughout the body, including the lungs, adrenal glands, and lumbar spine. In the end, the patient was successfully moved from the ICU after weaning from ECMO and the ventilator, and then transferred to an infectious disease specialist hospital for standard anti-tuberculosis therapy.

Conclusions

ECMO has won the opportunity for the diagnosis and treatment of this young patient who suffered from a rare cause of cardiac arrest and finally achieved a good prognosis.