Acute Stress Reaction (HB)

Acute stress reaction is a condition that looks a lot like the forms of shock above but is actually a temporary problem with the nervous system. ASR should not be a primary diagnosis without ruling everything else out.  Always assume other problems are the cause.

ASR is a very common occurrence in medical emergencies and will affect both rescuers and patients. It can absolutely occur in conjunction with other problems, and it can mask symptoms of real problems.

Acute stress reaction is called “psychogenic shock,” but that is an incorrect assignment since it is not truly shock, and the outcomes are not the same. ASR resolves with time. The other forms of shock do not resolve without managing the underlying cause.

There are two types of an acute stress reaction: Sympathetic and Parasympathetic. We can use an easy mnemonic to remember them. Someone in Sympathetic ASR “Spazzes out.” A patient in Parasympathetic ASR “Passes out.”

Sympathetic ASR happens when the body dumps adrenaline into the bloodstream in response to the event. Sympathetic ASR is really the fight or flight response. It mimics volume shock with an increase in heart rate and respiratory rate. It also masks pain (through the release of some other hormones). Masking can make it challenging to do a complete assessment on a patient as they may not appropriately respond or identify an injury. This is an important factor for doing a spinal exam, and we will revisit it in that lesson.

Parasympathetic ASR has the opposite effect. It causes a sudden drop in the heart rate, which results in a drop in pressure in the brain. Parasympathetic ASR is like the “playing possum” response. The presentation could be nausea or fainting. It mimics the shell to core affect and presents as a severe mental status change in the patient. They could present as cool and pale and unresponsive, which looks a lot like decompensated shock.

An acute stress reaction is NOT a life-threatening emergency. You can correct it with reassurance and time and removal from the stimulus that caused the anxiety which triggered the response. Just remember that ASR can mask real problems, so make sure you do a complete assessment and reassess after the patient has calmed down.

If you have a positive mechanism of injury for any type of shock, treat it as shock until you can confirm it is not.