The Emergency Medical Retrieval Service (EMRS) provides an aeromedical retrieval service to remote and rural communities in Scotland. They examined 300 retrievals over a five year period and showed a correlation between amount of critical care interventions required and total time on scene (defined as the total length of time between the aircraft landing and taking off from the scene, this includes access to patient, transfer to the helicopter and packaging for flight departure). Median scene time for both medical and trauma patients was 60 minutes.
The authors remind us that critical care secondary retrieval from rural healthcare facilities has many similarities to prehospital care (primary retrieval), and therefore consideration of scene times is of interest. On-scene times and critical care interventions for an aeromedical retrieval service Emerg Med J. 2010 Aug 19. [Epub ahead of print]
Aeromedical retrieval specialists in Scotland developed a simple, cheap, effective in-flight cooling protocol using intravenous (IV) cold Hartmann’s solution and chemical cooling packs. Fluids cooled in a fridge (4°C) were transported in an insulated cool box; the patient was sedated, paralysed and intubated, and controlled ventilation started. The patient was then cooled by IV infusion of 30 ml/kg of cold Hartmann’s. Chemical ice packs were activated and placed in the axillae and groin. The time interval between successful resuscitation and the patient being retrieved and flown to an Intensive Care Unit (ICU) was at least 3.5 h. Cooled patients had a mean decrease in body temperature during retrieval compared to patients not cooled (−1.6 °C vs. +0.9 °C, p = 0.005) and a lower body temperature on ICU arrival (34.1 °C vs. 36.4 °C, p = 0.05). Two of the 5 cooled patients achieved target temperature (<34 °C) before ICU arrival. No complications of in-flight cooling were reported.
It is often recommended that vasoactive agents are infused via central lines because of the risk of infiltration and tissue injury. The Children’s Hospital Boston transport team describe transport of 73 infants and children who were treated during interhospital transport with vasoactive medications via a peripheral intravenous line.
Median transport time was only 38 minutes (range 3[!!]-216) and median age was 1 (birth to 19) .
Dopamine monotherapy was given in 66 patients, adrenaline (epinephrine) monotherapy in 2, dobutamine plus phenylephrine in 1, dopamine and epinephrine in 3, and dopamine, dobutamine, and epinephrine in 1 patient.
In this retrospective study no patients developed infiltration or other complications related to peripheral vasoactive agents during interfacility transport. Eleven of the 73 patients, however, did develop infiltrates related to vasoactive infusion after arrival at the accepting institution; all infiltrates involved only minimal blanching and/or erythema, and all resolved without significant intervention and caused no lasting tissue injury. The risk of infiltration rose with increasing medication dose and duration of use.
Interesting that noradrenaline (norepinephrine) wasn’t used. This study is interesting but the overwhelming predominance of dopamine makes it hard to extrapolate this to European or Australasian practice. The Use of Vasoactive Agents Via Peripheral Intravenous Access During Transport of Critically Ill Infants and Children Pediatr Emerg Care. 2010 Aug;26(8):563-6
A paediatric critical care transport service encountered elevated tracheal tube cuff pressures (>30 cmH20) in 41% of 60 consecutive care studied, and over 60 cmH20 in 30%. This measurement was taken on arrival at the bedside, not in flight.
Cuffed tubes are good, but we need to keep an eye on the pressures.
This is in keeping with the results of an adult study previously blogged on this site. Endotracheal Tube Cuff Pressures in Pediatric Patients Intubated Before Aeromedical Transport Pediatr Emerg Care. 2010 May;26(5):361-3
The Children’s Acute Transport Service (CATS) in the UK performed 2106 interfacility transports between April 2006 and March 2008. The stabilisation time averaged just over 2 hrs. Stabilisation time was prolonged by the number of major interventions required to stabilise the patient before transfer and differed significantly between various diagnostic groups. The length of time spent by the retrieval team outside the intensive care environment had no independent effect on subsequent patient mortality.
They have shown that stabilisation time can be influenced by a number of patient- and transport team-related factors, and that time spent undertaking intensive care interventions early in the course of patient illness at the referring hospital does not increase patient mortality. In the authors’ words: ‘the “scoop and run” model can be safely abandoned in favor of early goal-directed management during interhospital transport for intensive care.‘
There’s NO rush guys! Effect of patient- and team-related factors on stabilization time during pediatric intensive care transport Pediatr Crit Care Med. 2010 May 6
An interhospital transport service introduced a no infusions policy for patients being transferred for primary coronary intervention, instead giving a bolus of heparin and glycoprotein 2b-3a inhibitor prior to transfer, along with non-intravenous nitrates (if needed). Discontinuing infusions during transport resulted in a significant reduction in transport times with no adverse effect on hospital length of stay or mortality. It did not significantly extend the time the patient spent in the catheterisation laboratory, nor did it impact the incidence of TIMI III flow. It did not impact the incidence of readmission to the hospital for cardiac-related chief complaints. Transporting without infusions: effect on door-to-needle time for acute coronary syndrome patients Prehosp Emerg Care. 2010 Apr 6;14(2):159-63
Plasma levels of adrenaline and noradrenaline increased signficantly in patients with acute coronary syndrome during ambulance transportation – a finding in keeping with studies on normal volunteers. I wonder how much more of an effect helicopter retrieval might have? Emergency ambulance transport induces stress in patients with acute coronary syndrome Emerg Med J. 2009 Jul;26(7):524-8.
Over twelve years in Queensland the RFDS undertook over 72000 fixed wing retrievals, including over 4000 critically ill patients. Trauma was the commonest diagnostic category. There were only 90 primary retrievals, from locations without healthcare facilities – less than one per month on average. This fascinating service covers vast distances, low population density, and a high number of indigenous people. Aeromedical retrieval for critical clinical conditions: 12 years of experience with the Royal Flying Doctor Service, Queensland, Australia
J Emerg Med. 2009 May;36(4):363-8 http://www.ncbi.nlm.nih.gov/pubmed/18814993
Bispectral index monitoring (BIS) was applied to 57 intubated patients transported by a Helcopter Emergency Medical Service (HEMS), demonstrating (1) that the patients were adequately sedated, (2) BIS works in helicopters, and (3) there is enormous scope for publishing work related to the retrieval environment – anything is of interest! Bispectral index monitoring in helicopter emergency medical services patients Prehosp Emerg Care. 2009 Apr-Jun;13(2):193-7
Further evidence from the UK shows that patients with acute traumatic brain injury suffer delays in the neurosurgical evacuation of intracranial haematomas which are increased from an average of 3.7 hours to 5.4 hours if they have to undergo interhospital transfer. Coordinated regional trauma systems please! A prospective study of the time to evacuate acute subdural and extradural haematomas. Anaesthesia. 2009 Mar;64(3):277-81