Pre-hospital and Retrieval Environment – an excerpt from my Prehospital Anaesthesia and Airway syllabus

Pre-hospital and Retrieval Environment

The environment which we work in is unforgiving. It is a given that we will always be working with limited resources and staff. As a retrieval anaesthetist once quipped to a course class “There is no emergency button to push on the wall!” In this setting, it takes careful planning and the right frame of mind to provide emergency anaesthesia and appropriate airway management, keeping the cardinal rule of pre-hospital medicine in mind at all times : SAFETY.

Safety during pre-hospital work begins with understanding and mitigating environmental factors.

For example what safety issues in the environment can you identify in this pre-hospital image, where a retrieval team is about to intubate a trauma patient (in background) whilst two other responders tend to another trauma patient?

Clearly there is the environmental issue of remaining on a hot road surface in midday sun. Whilst they are trying to mitigate this by offering makeshift shade to both patients, one alternative would be to move the patients into shade or a sheltered location. Emergency airway management should be undertaken as a general priority but not at the expense of safety! One must be careful of remaining on a road with traffic as a hazard. Mitigating strategies taken here were to setup road blocks using police and divert traffic down alongside the road. With less staff and resources, it would be simpler and safer to move the patients off the road. Look again at the location of the damaged car. It is close to the treating team and their patient. What if there was an engine fire? What about broken glass? Once again moving away from safety risks would be simpler rather than staying at the risky location for the reason of securing the airway prior to moving.

Emergency anaesthesia and airway management can be very challenging in hot glaring sunlit settings. Portable equipment such as monitors may have trouble displaying properly in midday sun. Intubating using direct laryngoscopy becomes challenging if ambient sunlight drowns out the light of your laryngoscope. Endotracheal tubes start to soften significantly above 40 deg Celsius ambient temperature.

Now consider this photo and what environmental safety risks there are?

Apart from the obvious ones like fire risk and broken glass as in the last image, we have added factors of night time and cold exposure. Night operations bring unique challenges of maintaining orientation and navigation. From a clinical care viewpoint, you might need to be prepared to do things under suboptimal torchlight. Cold ambient temperature can be lethal to trauma patients. Once again the issue of getting the patient to a sheltered position prior to anaesthesia and airway management might be crucial to overall patient care.

What about the aeromedical setting? Helicopters are noisy and vibrating boxes, making any assessments and procedures challenging inflight. If emergency anaesthesia and airway management are required inflight in a helicopter, then these environmental factors must be taken into account. For example a post intubation tension pneumothorax or right main stem bronchial intubation may be very difficult to accurately detect in the noisy cabin. Fixed wing aeromedical retrievals add extra challenges of altitude related hypoxia and gas pressure changes. The air filling tracheal tube cuffs and laryngeal mask airways will expand with altitude. Vibration in both aircraft settings may increase metabolic rate and oxygen consumption as well as greater sedation and analgesic requirements for the anaesthetised retrieval patient.

Ultimately the major challenge of the pre-hospital and retrieval environment for the clinician is a logistical one. You are deliberately faced with a low resource setting where usual hospital based supplies of equipment and staff are simply not available. For the provision of safe pre-hospital anaesthesia and  advanced airway management, adequate supplies of oxygen are crucial and so it is incumbent upon the retrieval clinician to determine the duration of anaesthesia most likely required for the conditions encountered.

A simple but effective strategy that we teach in RFDS retrieval medicine is to plan the retrieval anaesthesia as if for a major surgery of several hours duration. Therefore the clinician can calculate the oxygen supply required for the duration of the retrieval as well as plan for appropriate sedation, analgesia and monitoring. Secure reliable intravenous access and adequate circulatory resuscitation must have occurred prior to the aeromedical retrieval just as would occur for any major surgery of several hours duration. Therefore the clinician can calculate the oxygen supply required for the duration of the retrieval as well as plan for appropriate sedation, analgesia and monitoring. Secure reliable intravenous access and adequate circulatory resuscitation must have occurred prior to the aeromedical retrieval just as would occur for any major surgery.

THIS CHAPTER WAS TAKEN FROM MY PREHOSPITAL ANAESTHESIA AND AIRWAY SYLLABUS FOR RFDS STAR PROGRAM

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