Low GCS - a case discussion

Low GCS - a case discussion
Photo by Tim De Pauw / Unsplash

Podcast Episode

The aim of this post

The goal of Anaestheasier is to generate a community amongst our members where we can share tips and tricks and best practice from across the world. As such we thought it might be interesting and useful to go through cases we've seen and break down what happened, what we did and why - for two reasons:

  • For our readers to learn what an anaesthetist does in each scenario
  • To get feedback on how others feel we could have done better

I've tried to write it in a way that makes it accessible to all, whether you're a student, doctor, anaesthetist, paramedic, nurse, associate practitioner - hopefully it is useful, and please don't hesitate to ask any questions at all - even if it's just to clarify something we've said.

For the medical students

Every medical student I have worked with has said essentially the same thing:

"Anaesthetics is a huge specialty but gets little-to-no attention at medical school."

We have made it our mission to right this wrong.

And for the seasoned anaesthetists among you - let it rip!

Seriously - we want you to critique our management, suggest what we could improve or highlight anything that was just plain wrong - so that we can all become better anaesthetists.

Give us your best shot in the comments!

Podcast Episode

The pre-alert

I was the anaesthetic registrar on call, fast bleeped to the resuscitation bay in the emergency department with only "medical emergency with anaesthetics" in the way of information.

I arrive to find the ED team preparing the bedspace, and the consultant briefs us on what to expect:

  • A 47 year old male has been found unconscious in his car
  • Multiple packets of pills and an empty bottle of whisky
  • GCS 3*, respiratory rate of 6, no response to naloxone
  • Arriving in five minutes

That's all we know.

*GCS = Glasgow Coma Score - a measure of unconsciousness - which goes from 3 (super unconscious) to 15 (wide awake and making sense). Below 8 we worry about the patient's ability to cough effectively and protect their airway.

The preparation

While the diagnostic question of 'what's going on' is clearly very important for the patient, the more pressing issue for the anaesthetist is 'am I going to intubate?'.

As always there are only ever two reasons to intubate someone:

  • To protect their airway
  • To replace their work of breathing

This patient - if he genuinely is GCS 3 - is almost certainly not protecting his airway adequately and is at high risk of aspirating if he were to vomit or bleed into his mouth.

He also has a very low respiratory rate, which may suggest an inadequate work of breathing - but we'd need to examine him and get an arterial CO2 level to determine whether he's breathing effectively.

A raised arterial CO2 level is a key marker of inadequate ventilation

Let's get ready to tube.

I had enough information at this point to suggest that we're likely to intubate, and so we started getting kit ready:

  • Intubation checklist
  • Mapelson C breathing circuit with facemask - (A fancy bag-valve mask)
  • Suction - (To clear out secretions, blood and vomit from the mouth)
  • Laryngoscopes (Mac 3 and 4, and videolaryngoscope)
  • Endotracheal tubes - (size 8 and 7.5)
  • Bougie - (A guide for the tube if intubation slightly tricky)
  • Oropharyngeal and nasopharyngeal airways
  • Supraglottic airway (IGEL)
  • Front of neck access kit (scalpel, bougie, size 6 tube)
  • Induction medications (Propofol, alfentanil and rocuronium)
  • Emergency medications (Metaraminol, adrenaline, atropine)

Check out our airway kit video below for more information on the above.

The assessment

The paramedics whisk the patient into the bedspace, and we swiftly get him shifted over to the bed and established onto our monitoring.

He was profoundly unconscious, completely unrousable to voice or painful stimulus, and was tolerating having an oropharyngeal airway in his mouth, suggesting his protective airway reflexes weren't doing much at all.

What the monitoring told us

  • ECG - sinus rhythm, 80 beats per minute, no ectopics or ST changes
  • Blood Pressure - 155/100
  • Pulse oximeter - Saturations 100% on 15 litres oxygen via non-rebreathe mask

If he's overdosed on a drug or medication, it could have cardiotoxic effects, but the ECG is somewhat reassuring so far.

His blood pressure is high, which suggests he is likely to be able to tolerate the effects of the induction drugs used for intubation. If his blood pressure were low (e.g. 90/55) then I would use ketamine rather than propofol.

His oxygen saturations are high, but remember this is on 15 litres of oxygen so can be falsely reassuring. The key is to rapidly titrate down the oxygen you're giving until his saturations are about 94-98% - this is how much he actually needs. (It was about 4 litres in this case).

The decision

We try and avoid intubation wherever possible, because it's a risky procedure and putting someone's lungs on the end of a tube connected to a ventilator isn't all that good for them.

They often wake up.

Having taken a more thorough history from the paramedics and next of kin, it seemed that this was most likely acute alcohol intoxication with a pinch of paracetamol and ibuprofen overdose thrown in for good measure.

The number of pills he'd taken probably didn't add up to an overly toxic dose, however this should never be assumed and blood levels should be taken regardless. Because we didn't know when he'd taken the paracetamol - we started N-acetyl-cysteine.

We see a lot of people in the emergency department with acute alcohol intoxication and the vast majority of them simply wake up after being allowed time to process the alcohol. We give them fluids and antiemetics to help this process along but otherwise they tend to sort themselves out.

However in this case, given just how profoundly unconscious he was, and the fact that he had this oropharyngeal airway in without any cough or gag reflex at all, if he vomited it could result in a catastrophic aspiration.

So we decided he needed a tube.

The intubation

Intubation is 90% preparation and 10% skill, maybe less - the ergonomics and set up are crucial.

We got him positioned with his head right at the end of the bed, chin up with a pillow under his neck to extend the neck and bring his head forward - the sniffing position - which makes finding the vocal cords vastly easier.

We then preoxygenated with 15 litres oxygen to fill his lungs up and buy us time while we faffed about trying to get the airway in after he stops breathing (because of the drugs we're giving).

We ran through the checklist to ensure we weren't missing anything, and then we gave the induction drugs:

  • Alfentanil - a fast acting opioid to reduce the stimulating response of laryngoscopy
  • Propofol - sedation, but a much-reduced dose than normal, as the patient was already unconscious (50mg rather than around 200mg)
  • Rocuronium - a muscle relaxant to ensure the vocal cords allowed the tube through, and to stop the patient coughing

Here's the contentious bit - I used a McCoy blade with the videolaryngoscope on standby. Many people will completely disagree with this, saying that a videolaryngoscope should be the first port-of-call.

The key is to use the tool you're best at using, but also to be versatile and able to adapt in case of difficulty.

As it was, the intubation went off without a hitch, and we got the patient safely established onto the ventilator, and shipped up to the intensive care unit, where he could safely sleep off his hangover and be woken up by the intensive care team in the morning.

So what do you think?

  • What would you do differently?
  • What doesn't make sense?
  • What else would you like to know?

Either reply in the comments or email us at Anaestheasier@gmail.com if you'd rather submit an anonymous question for us to answer.

Check out our airway equipment video