Transport of the critically ill patient

This chapter is directly relevant to Section 2.1.1 of the CICM Second Part General Exam Syllabus (First Edition), which specifically lists “transport of the critically ill patient” as core knowledge for the intensive care specialist. Transport of the critically ill patient is the subject of a CICM official guideline document (IC-10 Guidelines for Transport of Critically Ill Patients) and is therefore fair game for exam questions, which imperils the trainees who generally tend to ignore the CICM professional documents page.  It is therefore unsurprising that questions on this topic are frequent but often done poorly. Examples include:

 The answer to all such questions can be found in college policy documents. ANZCA also have a policy document- Guidelines for Transport of Critically Ill Patients- which has been endorsed by CICM.  

In an abridged form, the recommendations are listed below. For the interested reader, Milligan et al (2011) is an excellent short review, and Le Cong & Ramin (2014) would be the next step up in the level of detail. Essential Aspects of Aeromedical Retrieval by Ramin & Le Cong (2012) or  Aeromedical Transportation: A Clinical Guide by Terence Martin (2006, 2nd ed) would satisfy all possible retrieval-related questions but are too long to recommend as essential resources.

Principles and practice of interhospital transfer

Basic rationale of interhospital transfer 

  • Critically ill patients are at increased risk of morbidity and mortality during transport
  • Risk can be minimized:
    • Careful planning
    • Appropriately qualified personnel
    • Appropriate equipment
  • There should be no hiatus in monitoring or therapy

Vehicle factors

  • Factors that dictate the choice of transport:
    • Determined by nature of illness, urgency of retrieval, and the distance to the receiving centre
    • Need to be mindful of the effects of transport on the illness (eg. the effect of low cabin pressure on gas-filled obstructed bowel loops)
    • Number of staff and volume of equipment
    • Road conditions, weather conditions
  • Advantages and disadvantages of different modes of transport:
     
    Advantages Disadvantages
    Road transport by ambulance
    • Quickest to arrange
    • Cheaper
    • Less danger to crew
    • No complications of altitude
    • Not affected by inclement weather
    • Able to pull over to perform a lifesaving procedure, if needed
    • Range is limited
    • Speed is limited
    • Road access is required
    • A lot more vibration, depending on the road surface
    Air transport by helicopter
    • Faster to organise than fixed wing
    • Rapid transit time
    • VTOL: does not need an airport (flexible with landing sites, eg. corn field)
    • Less turbulence, smoother ride
    • Range is limited 
    • Highly weather-dependent
    • Expensive
    • Noisy for crew and patient; communication possible only via headset
    • Small cabin, limited room
    • Complications of altitude (albeit mild); cabin not pressurised
    Air transport by fixed wing aircraft
    • Highest range
    • Fastest speed
    • Less weather dependent than helicopter
    • Large cabin, more equipment is available
    • Better temperature and noise control than helicopter
    • Can be pressurised at altitude
    • Slowest to organise
    • Most expensive
    • Need to load into an ambulance, then load onto aircraft at the airport, then disembark at an other airport and load into another ambulance (i.e. in effect three separate transfers)
    This table was derived in whole from this excellent summary by shakEM.co.nz. Theoretically, methods of retrieval may be as diverse as are the vehicles available, but CICM trainees would not be expected to discuss them.

Personnel

  • At least two people to accompany
  • Medical staff with training in airway management and advanced cardiac life support

Equipment

  • Airway equipment
  • Pericardiocentesis equipment
  • Pleural drainage eqipment
  • Suction
  • Ventilator
  • Oxygen supply (in excess)
  • Defibrillator
  • Thermal insulation
  • Monitoring equipment
  • All drugs checked and labelled

Monitoring

  • Pulse oximeter
  • Capnometer
  • ECG
  • NIBP or arterial line
  • Airway equipment must have disconnection alarms

Patient preparation

  • Ideal patient is intubated, ventilated and paralysed
  • The patient should ideally be stabilised on a transport ventilator before departure
  • Vascular access should be secure; you should not be doing any elective procedures during transfer
  • One last pre-departure assessment

Communication:

  • Bed availability
  • Accepting primary consultant
  • Accepting unit (ICU)
  • Next of kin
  • Documentation travels with the patient
  • Receiving unit receives updates on transfer status

In addition to the college documents, the retrieval enthusiast would be entertained by the 2004 article by Warren et al, which offers a summary of the reasoning and evidence behind many of the abovelisted guidelines. Unsurprisingly, this is not an area rich in high quality RCT evidence, and much of the recommendations are based on expert opinion and personal experience.

Intrahospital transfer

Question 21 from the second paper of 2023 asked about a bog-standard household chore of the large ICU, the transport of a trauma patient to CT for a CT brain. The juggle of the drains and the kabelsalat of infusion lines is an important formative experience of the ICU trainee. Again, IC-10 is the definitive guide referred to by the college in their answer, but it contains very little about intrahosptial transport, merely mentioning that the principles are all the same. It also seems to copy the ANZCA PS52(G) document. 

Preparation:

  • Staff
    • ("at least of an appropriately qualified nurse, an orderly, and a medical practitioner with the specific skills and training required for such transport")
  • Communication
    • Destination notified of departure
    • Porters notified of the timing of return transport
    • Intubation grade is communicated to the transporting staff
    • Documentation of observations and events during trasport
    • Handover to the home team on return
  • Emergency equipment
    • Airway drugs and sedation/NMJ relaxants checked and present
    • Airway equipment
  • Safety equipment
    • Two oxygen cylinders, full
    • Monitor batteries
    • Spare IV line

Relevant guidelines for transport of the critically ill patient

The following should be considered essential, as this is what the exam questions are likely to be based on (and readers from across the seas can look to their own critical care authorities for similar professional statements)

Evidence to describe the transport of the critically ill patient

How much evidence could there be to support our practice here? Well. Fortunately a thing as expensive and politically interesting as aeromedical retrieval is carefully logged and documented, allowing for robust audit. From this, we have papers like Franklin et al (2021), which was a retrospective analysis of 5 years of retrievals from Queensland (spoiler: 41% were "priority 4", i.e. elective transport for some kind of appointment or investigation).

Controversies in the transport of critically ill patients

Is the delivery of aeromedical retrieval services to remote areas cost-effective? Perhaps it is (Taylor et al, 2010), or perhaps it's not (Wieland et al, 2023). 

Risks in the transport of critically ill patients

The risk to the patient is already abundantly covered by the above. Risk assessment of the retrieval staff by Gray et al (2019) is perhaps more interesting, answering questions like "is your overweight pilot's OSA a liability?"