Podcast 862: How to Apply a Painful Stimulus

Contributor: Travis Barlock MD

Educational Pearls:

When might you need to apply a painful stimulus in a medical setting?

• The main reason is to assess the patient's level of consciousness, such as when they are waking up from anesthesia or have potentially suffered a brain injury.

• It can be part of the Glasgow Coma Scale (GCS) if patients are not responding to auditory stimuli.

• Possible levels of consciousness include Alert, Lethargic, Obtunded, and Comatose (ALOC)

What are the approved ways to apply a painful stimulus to assess central nervous system function?

• Trapezius squeeze. Grab the trapezius muscle and twist (contraindicated in clavicle fractures).

• Supraorbital rim pressure. Find the notch in the supraorbital rim of the patient and push hard with your thumb (contraindicated in facial fractures).

• Mandibular pressure (not mentioned). Press hard at the angle of the jaw on the mandibular nerve (contraindicated in mandible fractures).

• Sternal rub. Push down with your knuckles into the patient's sternum and rub vigorously (contraindicated in chest injury/surgery).

• Each technique should be done for between 15 and 30 seconds.

• If skin damage is observed in one location, move to a different location. This is especially true of the sternal rub.

Important note: Peripheral techniques such as nail tip pressure should only be used to evaluate spinal nerve reflexes and not as a method of assessing the level of consciousness.

References

1. Lower J. Using pain to assess neurologic response. Nursing. 2003 Jun;33(6):56-7. doi: 10.1097/00152193-200306000-00047. PMID: 12799591.

2. Middleton PM. Practical use of the Glasgow Coma Scale; a comprehensive narrative review of GCS methodology. Australas Emerg Nurs J. 2012 Aug;15(3):170-83. doi: 10.1016/j.aenj.2012.06.002. Epub 2012 Aug 3. PMID: 22947690.

3. Mistovich JJ, Krost W, Limmer DD. Beyond the basics: patient assessment. Emerg Med Serv. 2006 Jul;35(7):72-7; quiz 78-9. PMID: 16878751.

4. Naalla R, Chitirala P, Chittaluru P, Atreyapurapu V. Sternal rub causing presternal abrasion in a patient with capsuloganglionic haemorrhage. BMJ Case Rep. 2014 Apr 7;2014:bcr2014204028. doi: 10.1136/bcr-2014-204028. PMID: 24711478; PMCID: PMC3987201.

Summarized by Jeffrey Olson, MS2 | Edited by Jorge Chalit, OMSII