This post, detailing my reflections on clinical retrieval medicine, is the third in a series recording my reflections on the past twelve months, which I have spent working for Sydney HEMS in prehospital and retrieval medicine. The first post covers medical education – you can find it here1. The second covers human factors – you can find it here2.
This post is about the clinical lessons I’ve learned during my year of prehospital and retrieval medicine. Although we (as UK-based EM clinicians) do a lot of “critical care”, the amount of decisions we make and procedures we undertake in the very sickest patients is very variable by department. I have worked in Emergency Departments in the UK where intubations, for example, are routinely undertaken by the ED team and others where it is common practice to contact colleagues from intensive care or anaesthesia with the expectation that they will perform such tasks. I do not want to get into a debate here about what is right; however, the result of this variation in practice is that while managing the primary trauma patient was very much my clinical comfort zone, the management and transfer of the critically ill patient was absolutely not. This sits at odds with our Australian ED colleagues, for whom responsibility for those first few hours of critical care (including airway management, central venous access, commencement of inotropic support…) falls squarely in their lap.
With this in mind, much of my clinical reflection occurred during secondary (interhospital) tasking where I found myself reliving experiences from my ST2 days in anaesthesia/ICM or seeing theoretical knowledge in glorious technicolour.
Part Three – Clinical Retrieval Medicine: Sedation, Ventilation, Planning and Preparation
Adequate sedation in ED/ICU is not usually adequate for transfer
I would like to be clear here that I am in no way criticising the practices of ED/ICM colleagues – but transfer (by any modality) is a pretty stimulating process and almost without exception the rate of sedation required to keep an intubated patient intubated and sedated for a transfer is not the same as that required when they are chilled out on a trolley or bed (even in a noisy emergency department). It can take time to achieve deep enough sedation for the transfer so it very quickly became my standard practice to make assessment of sedation level my first assessment and increasing the rate of infusion of sedative meds my first action on arriving at the bedside of an intubated patient.
Propofol isn’t going to cut it for almost all young male patients (especially those with burns)
This was a lesson I learned very quickly. One of my very early transfers was of an intubated young adult with relatively minor but painful burns, sedated when I arrived with a propofol infusion and some opioid analgesia. Propofol is a great sedative but it is not an analgesic and in young patients propofol can be metabolised incredibly quickly. The infusion pumps we used could only take a maximum of 33ml in a 50ml syringe… an odd quirk but an important one so when it became rapidly apparent that the sedation wasn’t deep enough I spent an uncomfortable 30mins in the back of the ambulance “chasing” his sedation and analgesia, trying to keep him intubated and on the stretcher, and ultimately having to change a syringe on arrival at our destination. Even increasing both the propofol and the opioid I couldn’t keep up with his metabolism and the stimulating effect of the painful burn.
“Squeaky bum” jobs do make GREAT learning. From that job forwards, if I turned up to find the propofol running at 15ml/hr or greater I’d strongly consider changing to a different agent (or adding one) because I already knew that the ability to increase propofol sedation to meet the patient’s needs was limited.
Paralysis will make your life easier (but sedate properly first)
Of course, I could simply have paralysed the patient in the story above. That would definitely have kept him intubated and on the stretcher. However, awareness is a very real and very unpleasant state that we in the ED probably don’t think about enough. I won’t labour that much here as we do talk about it in the ED Transfers blog and podcast; I just think it’s important to remind ourselves regularly that we should be reaching for sedation and analgesia first and paralysis only once the patient is deeply sedated and well analgesed.
Ventilation is nuanced!
Oh goodness. There’s so much I can say here… almost worthy of an entire post on its own (except the anaesthetists know far more about this than I do). It’s helpful to remind yourself regularly about the basics of physiology and ventilation – this post over at EMDocs is a great starting point with some simple physiology thrown in. Of course there are some fantastic resources at EMCrit – Scott has a video lecture on basics of the ventilator, a handout in PDF form and a nice little linked summary paper of the more nuanced lung protective strategies you might need too. I’ve got some notes from a fantastic lecture by Geoff Healy I’ll try to get round to writing up into a blog post – I’ll add the link here.
BiPAP uses a lot of oxygen but it can be very useful for transporting a patient
Not every patient requires intubation for transfer. The Oxylog 3000+ does a reasonable job as a BiPAP machine – it may use a lot of oxygen (in which case you’ll need to do some maths to ensure you won’t run out along the way) but it’s a sensible alternative, particularly for shorter transfers.
Resuscitate BEFORE you intubate
That patient with RR 50, BP 90mmHg, HR 120? However much you know that they are sick enough to require intubation, expect them to arrest if you give an induction agent! Resuscitate first and even then anticipate hypotension – have inotropes ready and running. In this exact situation I gave fluids, sited arterial and central lines and started noradrenaline, gave a reduced dose of induction agent (fentanyl 2mcg/kg then less than 1mg/kg ketamine), bagged through the apnoeic period and still saw a responsive hypotension. A little adrenaline (mine was endogenous, the patient’s exogenous) got us both through – but as I had arrived to find the patient with those obs the local treating doctor had identified how sick the patient was and greeted me with the ominous phrase “I was just about to intubate him…”
Try to ventilate patients with metabolic acidosis as they’d ventilate themselves
This was something I learned in PICU back in my Paeds EM subspecialty year. Pre-intubation, patients with metabolic acidosis will have an increased respiratory rate to try to compensate for their low pH so when we ventilate them invasively we should maintain that high respiratory rate. Allowing the pCO2 to increase can cause bad things to happen… A slightly more scientific explanation can be found here and an old case-based podcast from EMCrit here.
Sometimes getting the sedation, analgesia, paralysis and ventilation right will drop the BP
That’s ok, just expect it – I went to retrieve a young patient who I found to be inadequately sedated, not paralysed, not synchronising his breaths with the ventilator and as a result horribly tachycardic, hypertensive and generally miserable. Increasing sedation and analgesia, paralysing when he was deep enough and then adjusting the ventilation resulted in a drop in his blood pressure (for a better understanding of the effects of positive pressure ventilation on cardiovascular physiology, try this and this) so satisfying myself that I hadn’t caused a pneumothorax, I gave a little more fluid and increased the inotropes. The transfer went pretty smoothly.
If you’ve got time, time spent planning is never wasted
This is true for pre-alerts to the ED as much as it is for retrieval missions – you can use time to allocate roles, draw up drugs, prepare equipment, run through a checklist, outline mental models, have a bathroom break (or some food)… The limit of what you can achieve is determined simply by the time you have. Use it!
With enough time, you can prepare for anything
One memorable, tragic job saw the retrieval team waiting for a paediatric patient anticipated to be in cardiac arrest. There was absolutely no way to get the care to the patient any sooner – as a result I had more time to prepare for a paediatric cardiac arrest than I had ever had before. As a result, it was the smoothest arrest I have ever been involved with (particular credit to the road paramedics and their amazing cannulation skills) and I am certain this was very important for the clinical team and for the family who were present. Being able to provide care in a calm and compassionate manner (with extra brain space freed up for communication and support of those present) is invaluable.
Without enough time, you can work out what preparations will give the most benefit
Of course, there are other jobs where there is comparatively little planning and preparation time – so prioritising preparations that will benefit you the most makes sense. Summarising the clinical information you know in advance can help you formulate a mental model – sharing that with your team will inform your preparation decisions.
Sometimes it just makes sense to go with what you have
You can get quickly bogged down in wanting to provide all the care for a patient you possibly can but in some locations that’s just not appropriate. The balance of “can” and “should” is tricky and it’s a skill of the experienced clinician to know when to just go (have a listen to the recently released smacc podcast featuring Hazel Talbot on neonatal retrieval – in her case vignette she describes that sort of situation). Do that, but have a plan (and brief your team) for what you’ll do if things change.
If you’ve got a chance to change a battery/oxygen cylinder/restock – do it
Sometimes you get the opportunity to change or replace something that isn’t quite finished – but I’m a big believer in being as prepared as possible. I don’t want to be able to think “I wish I had swapped that monitor battery when I had the chance this morning…” You might need to balance this against basic human needs (eating, bathroom breaks etc., especially between retrieval missions – more on this in the later “self care” post in this series) which is fair enough, just don’t let these things slide – that’s my advice.
Don’t move the patient without a plan for how you’ll manage if things fall apart
In the @SydneyHEMS service there are a couple of habits well established to guard against the work of the Evil Retrieval Weevil (similar to Hazel Talbot’s evil fairy and the airway spirits I deter by bringing the “difficult airway” trolley to the bedside for any ED intubation). We would always ensure we had a second IV “rescue line” with a bag of fluid attached but not necessarily running and an injection port accessible (for boluses of any medication you might need or a fluid bolus). We would take the “dropdown airway” bag (mentioned in the ED Transfer blog and podcast – you can see its contents here) into the hospital to collect the patient and to deliver them at the other end, often keeping it available as a source of emergency airway support should things go awry. The truths from the ED Transfers blog and podcast are absolute – think about what you’ll do if 1) the patient is suddenly sicker, 2) the patient needs an airway intervention, 3) the transfer takes much longer than expected. PPPPPP (and the Evil Retrieval Weevil) 🙂
Next post in this series: more clinical retrieval medicine, including paediatrics, drowning and ketamine!
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