RickInOz

It’s been a little while since the last one of these, but on with the series of posts about the job I used to do ad-hoc and now do full-time. Thus far we have covered everything up to the point where the stress really starts.

Generally when we pick patients up, it is from the controlled environment of a hospital. While many of these hospitals are very small and have limited resources, it is still affords a degree of security due to the backup of other staff and ease of communications with our bosses back in Adelaide. Regardless of comfort, at some point we have to get going as, in many situations, the treatment the patient really needs is being in a big tertiary centre.

By now we have already packaged the patient, started medicines and done sufficient procedures to make them as fit as possible for retrieval. Then we load them onto our transport platform and high-tail it back to Adelaide. Once en-route there are a number of important considerations unique to retrieval medicine:

Access to the patient:

Every mode of transport we use is very limited in space. This applies across ambulances, helicopters and planes. The patient is strapped to a very narrow stretcher and usually has to be placed against one bulkhead/wall. This means we can only get at the patient from one side. Therefore if we need to give medicines through a drip in the arm closest to the wall, it is difficult unless we have already set up a contingency IV line.

It is not just access to one side of the patient that is difficult. We are also limited in space at the “head-end” of the stretcher. This makes performing interventions like intubation far more tricky and stressful. In a hospital there is plenty of space and we can always move the patient’s bed to get more space – not so on retrievals. For that reason we often electively perform procedures that would not be necessary in hospital, so there is one less thing to worry about in transit.

Hypoxia:

If you have ever seen a picture of a climber on Everest you will notice that they, on the whole, have an oxygen mask on. The reason for this is the drop in ambient atmospheric pressure with increasing altitude. Just as there is less air available, there is less oxygen. For healthy people this makes little difference, as evidenced by airline passengers feeling comfortable whilst in the air, even though they are being exposed to the equivalent altitude of 6000 feet above sea level. Unfortunately sick patients do not fare so well and are often intolerant of the decreased oxygen tension. This leaves us with a few options.

Firstly, we can either come back by road – no problems with oxygen, but it obviously takes longer. Secondly, if going by helicopter, we can ask the pilot to fly at a lower altitude. The trade off is slower flying speed but we can often reach a compromise on altitude rather than coming back over the tree-tops. Finally, if coming back by RFDS plane, we have a neat little trick available. The planes have been modified so they can create a sea-level cabin – that is the plane can pressurise the cabin beyond that available on commercial aircraft. You might think we use this facility often but actually we tend not to as it uses a great deal of fuel and makes for a bumpy ride as the plane has to fly lower.

Acceleration/deceleration syndrome:

The human body is designed to be upright most of the time. The entire cardiovascular system is based on our evolution as bipedal. This means we put some of our patients at a disadvantage by lying them flat on a stretcher. Most tolerate it fairly well so this isn’t the principle problem. The main issue is where blood flows under inertia. Consider how you feel if you do a handstand, or hang your head over the edge of the bed. Pretty stange isn’t it. This happens to the patient when we decelerate sharply as occasionally happens in the ambulance. The opposite often occurs (with blood rushing away from the heart) during the climb in the RFDS plane. Either can be significantly detrimental to the patient and lead to significant haemodynamic instability.

Extremes of temperature:

In summer this state gets very hot and in winter very cold. When moving patients between buildings and vehicles we expose them to ambient temperature. In winter we can always cover them with blankets, but we are limited in summer in lieu of a portable air-con unit!

In transit this is also a problem. While sitting on the tarmac the planes equilibrate with outside temperature until the engines are started and the climate control runs. The same applies to ambulances and helicopters too. The latter presents the greatest challenge since we have no means of controlling temperature inside the cabin. In summer it can often be warmer than outside and in winter just as cold. It would be nice to say that there is a solution but unfortunately helicopters are not luxurious limousines.

So as you can see, we face many problems whilst en route to definitive care. But all of these are irrelevant by comparison to the consequence of leaving the patient in extremis with inadequate facilities and staff to manage them. As I said earlier – the most important part of retrieval medicine is the retrieval!