The transport of critical care patients requiring ventilator support is a dynamic task that requires precision and accuracy to ensure patient safety. Advanced tools have become smaller, hand-held, and easier to use in many environments. Whether working in aeromedical critical care transport at Duke Life Flight, deployed with the Vermont Army National Guard MEDEVAC, or now critical care transport with Boston Children’s Hospital, I have been in many different environments where point-of-care (POC) lab data has been crucial to patient outcomes. 

iStat findings

Recently published in Air Medical Journal, my team from Duke Life Flight showed our research on the usage of the Abbott Laboratory’s i-STAT device. In the single-center, retrospective study, we looked at 120 patient transports over a year period. It was found that 78 patients required intervention with things like ventilator changes, blood product administration, and / or electrolyte replacement¹. The data was gathered from rotor-wing, fixed-wing, and ground transports. Patient type included 35 extracorporeal membrane oxygenation (ECMO), 21 medical, 17 cardiac, 13 neonatal, 11 respiratory failure, eight gastrointestinal bleeding, six neurologic, five pediatrics, three trauma, and one organ donor1. Specific focus was placed on ECMO and neonatal transports, as there was little research on these two patient populations. It was concluded that the safe usage of the i-STAT could be utilized in air or ground critical care transport with no complications.

Other clinically significant research has been done on POC laboratory data. In North Carolina, our colleagues conducted research published in Air Medical Journal in 2016-2017 using the EPOC blood analyzer (Alere, Inc), which is the device used on their rotor-wings^2,3. But research on the use of POC lab data extends back even further – to as early as 2003, in an article in Clinical Chemistry. Using the i-STAT in fixed-wing and ground ambulances, they conducted a six-year retrospective study. It was conducted from 1996 to 2001 consisting of 1,146 i-STAT tests⁴. They concluded that a major limiting factor for the device was the cost of the cartridges. They mention that a risk-benefit analysis needs to be conducted when considering a POC laboratory program in critical care transport^2,4.

Changing patient management

I’d like to share three case scenarios from different critical care transport programs of my experience where POC laboratory was crucial for patient management. At Duke, we transported a large number of ECMO patients. These transports are highly dynamic and require a large number of resources. Many ECMO patients require frequent changes of the ECMO settings, ventilator settings, blood product replenishment, and acidosis management. Many times, we would arrive to the surgical suite or catheterization lab of an outside hospital to find the patient awaiting us. More frequently than not, our initial i-STAT arterial blood gas (ABG) would show an acidosis and / or a low hemoglobin. This allowed our protocol-based practice to initiate mechanical titrations or begin sodium bicarbonate therapy and administer blood products. 

During my deployment to the Middle East with the Vermont Army National Guard, we conducted both point-of-injury (scene) flights and interfacility critical care transports. My specific team conducted multiple two-plus hour trips from our small surgical team to the large medical treatment facility. These trips included the transport of intubated patients requiring multiple altitude changes due to varying levels of threat in our area of operation. They were conducted with transportable durable medical equipment (monitors and ventilators) which were over 10 years out of date, and portable oxygen D tanks that were constantly rationed to make the trip. The reliability of the end-tidal CO₂ and Sp02 monitoring for long-term trips was never comforting, when having to titrate FiO₂ to conserve oxygen. Having a POC device to confirm ventilation would have been the mission essential device to improve patient safety for our trips. 

Finally, my new experience with the Boston Children’s Hospital Critical Care Transport team finds us frequently at the isolette side of a premature infant patient at a small county or community hospital with limited resources. Bringing the large level-four neonatal intensive care unit resources to the small hospital nursery is crucial for the baby’s survival. Shortly after birth, we can bring emergent, life-saving treatment to determine cardiac defect, pulmonary hypertension, or other neonatal complication with the quantitative data supported from the iStat. Being able to interpret ABGs and electrolytes is the mainstay of neonatal resuscitation.

The future is bright

In conclusion, much more research needs to be conducted on the topic of POC laboratory data in critical care transport. Larger studies, from multiple programs, and, with more patients, need to be evaluated to confirm the clinical significance. However, it is feasible that devices such as the iStat can be used safely to guide critical care treatment in transport.