Hello all and welcome to my final Trauma Tuesday POTD!
Today we'll be discussing something that many of us were taught in medical school about trauma - "GCS less than 8 - intubate". This phrase has also been said about patients who are altered for other reasons - infection, tox, etc.
The thought process behind this is that patients who have a low GCS are at risk for aspiration, and we should secure the airway to prevent this. In trauma, it's thought that patients with low GCS have severe enough brain injury that they are at risk for depressed respirations, and intubation is done to prevent this.
Is GCS < 8 associated with decreased airway reflexes?
A study showed that 22% of patients with GCS of 15 had absent gag reflexes, 37% in GCS of 9-14, and 63% in patients with GCS < 8. So, it does appear that lower GCS has a higher percentage of absent gag reflexes, but 22% of patients with a GCS of 15 is a pretty high number to be solely using GCS as our measure.
Is it associated with more aspiration events?
A prospective study of 73 ED patients showed that none of the patients with a GCS <8 aspirated or required intubation. Actually, the only patient who required intubation in that study had a GCS of 12.
However, there have not been any RCTs studying this. A systematic review on this topic showed that there isn't enough evidence to draw a conclusion.
Decreased GCS can be due to a temporary cause, such as alcohol intoxication, as we often see. How often are we intubating someone for alcohol intox? Not frequently. So, it's important that we consider the full clinical picture before jumping to intubation.
In conclusion - when we need a quick and dirty guide, GCS < 8 is generally the cutoff that's used for us to consider intubation. However, it's important to consider the whole clinical picture and make sure the patient is not getting intubated unnecessarily and suffering the potential side effects of intubation. Also, conversely, GCS > 8 doesn't always mean that the patient is protecting their airway!
References:
Duncan R, Thakore S. Decreased Glasgow Coma Scale score does not mandate endotracheal intubation in the emergency department. J Emerg Med. 2009;37(4):451-455. doi:10.1016/j.jemermed.2008.11.026
Orso D, Vetrugno L, Federici N, D'Andrea N, Bove T. Endotracheal intubation to reduce aspiration events in acutely comatose patients: a systematic review. Scand J Trauma Resusc Emerg Med. 2020;28(1):116. Published 2020 Dec 10. doi:10.1186/s13049-020-00814-w
Ribeiro SCDC. Decreased Glasgow Coma Scale score in medical patients as an indicator for intubation in the Emergency Department: Why are we doing it?. Clinics (Sao Paulo). 2021;76:e2282. Published 2021 Mar 8. doi:10.6061/clinics/2021/e2282
Freund Y, Viglino D, Cachanado M, et al. Effect of Noninvasive Airway Management of Comatose Patients With Acute Poisoning: A Randomized Clinical Trial. JAMA. 2023;330(23):2267-2274. doi:10.1001/jama.2023.24391