Use of Helicopters to Reduce Health Care System Delay in Patients With ST-Elevation Myocardial Infarction Admitted to an Invasive Center

Air or Ground Transport to the Critical Care Resuscitation Unit: Does It Really Matter?

OBJECTIVE

Critically ill patients requiring urgent interventions or subspecialty care often require transport over significant distances to tertiary care centers. The optimal method of transportation (air vs. ground) is unknown. We investigated whether air transport was associated with lower mortality for patients being transferred to a specialized critical care resuscitation unit (CCRU).

METHODS

This was a retrospective study of all adult patients transferred to the CCRU at the University of Maryland Medical Center in 2018. Our primary outcome was hospital mortality. The secondary outcomes included the length of stay and the time to the operating room (OR) for patients undergoing urgent procedures. We performed optimal 1:2 propensity score matching for each patient's need for air transport.

RESULTS

We matched 198 patients transported by air to 382 patients transported by ground. There was no significant difference between demographics, the initial Sequential Organ Failure Assessment score, or hospital outcomes between groups. One hundred sixty-four (83%) of the patients transported via air survived to hospital discharge compared with 307 (80%) of those transported by ground (P = .46). Patients transported via air arrived at the CCRU more quickly (127 [100-178] vs. 223 [144-332] minutes, P < .001) and were more likely (60 patients, 30%) to undergo urgent surgical operation within 12 hours of CCRU arrival (30% vs. 17%, P < .001). For patients taken to the OR within 12 hours of arriving at the CCRU, patients transported by air were more likely to go to the OR after 200 minutes since the transfer request (P = .001).

CONCLUSION

The transportation mode used to facilitate interfacility transfer was not significantly associated with hospital mortality or the length of stay for critically ill patients.

Aeromedical Transport for Critically Ill Patients

Aeromedical transport (AMT) is an integral part of healthcare systems worldwide. In this article, the personnel and equipment required, associated safety considerations, and evidence supporting the use of AMT is reviewed, with an emphasis on helicopter emergency medical services (HEMS). Indications for HEMS as guideded by the Air Medical Prehospital Triage Score are presented. Lastly, physiologic considerations, which are important to both AMT crews and receiving clinicians, are reviewed.

Can Helicopters Solve the Transport Dilemma for Patients With Symptoms of Large-Vessel Occlusion Stroke in Intermediate Density Areas? A Simulation Model Based on Real Life Data

Background

This modeling study aimed to determine if helicopters may optimize the transportation of patients with symptoms of large vessel stroke in “intermediate density” areas, such as Denmark, by bringing them directly to the comprehensive stroke center.

Methods

We estimated the time for the treatment of patients requiring endovascular therapy or intravenous thrombolysis under four configurations: “drip and ship” with and without helicopter and “bypass” with and without helicopter. Time delays, stroke numbers per municipality, and helicopter dispatches for four helicopter bases from 2019 were obtained from the Danish Stroke and Helicopter Registries. Discrete event simulation (DES) was used to estimate the capacity of the helicopter fleet to meet patient transport requests, given the number of stroke codes per municipality.

Results

The median onset-to-needle time at the comprehensive stroke center (CSC) for the bypass model with the helicopter was 115 min [interquartile range (IQR): 108, 124]; the median onset-to-groin time was 157 min (IQR: 150, 166). The median onset-to-needle time at the primary stroke center (PSC) by ground transport was 112 min (IQR: 101, 125) and the median onset-to-groin time when primary transport to the PSC was prioritized was 234 min (IQR: 209, 261).

A linear correlation between travel time by ground and the number of patients transported by helicopter (rho = 0.69, p < 0.001) indicated that helicopters are being used to transport more remote patients. DES demonstrated that an increase in helicopter capture zone by 20 min increased the number of rejected patients by only 5%.

Conclusions

Our model calculations suggest that using helicopters to transport patients with stroke directly to the CSC in intermediate density areas markedly reduce onset-to-groin time without affecting time to thrombolysis. In this setting, helicopter capacity is not challenged by increasing the capture zone.