Bradycardia and ICP relationship?


I am reviewing the Neuro section of Hurst Reviews. For the treatement of ICP it mentions watching for bradycardia (not pumping out much volume).

I don't get the connection between ICP and bradycardia. I understand that the heart is pumping against more pressure, so not as much blood can get out.

But how does the bradycardia come into play?


118 Posts

I found this helpful for me to understand

The Cushing reflex classically presents as an increase in systolic and pulse pressure, reduction of the heart rate (bradycardia), and irregular respiration.[4] It is caused by increased pressure inside the skull.[4] These symptoms can be indicative of insufficient blood flow to the brain (ischemia) as well as compression of arterioles.[4][5]

In response to rising intracranial pressure (ICP), respiratory rate increases.[6] The increase in ventilation is exhibited as an increase in rate rather than depth of ventilation, so the Cushing reflex is often associated with slow, irregular breathing.[7][8]Mayer waves, which are waves in arterial blood pressure that can be seen in an electrocardiograph (ECG) register or blood pressure traces, are a symptom of a physiological response to falling blood flow. This often results in an increase in blood pressure.[7]


102 Posts

Hi. I am reviewing Hurst also but I don't see connection of increased ICP and bradycardia. There is hypoxia. What I noticed is that watch for bradycardia. Anyway, ask hurst thru email.

KelRN215, BSN, RN

1 Article; 7,349 Posts

Specializes in Pedi. Has 16 years experience.

Bradycardia is a LATE sign of increased ICP. If a patient gets to the point where they are presenting with Cushing's triad, they are in big trouble and intervention needed to happen like yesterday. I've seen patients do this and it is not pretty. Usually you've got minutes to get them to the OR before they herniate. Much more important is to watch for the early signs of ICP such as severe headache, double vision, vomiting and lethargy.

Think about what's going on in the brain when you have increased ICP. Blood pressure increases because it needs to be high enough to perfuse the brain so you get hypertension. In response to hypertension, the parasympathetic nervous system is stimulated and the heart rate becomes bradycardic. I don't usually like wikipedia, but I actually think this article describes it pretty well:

Cushing reflex - Wikipedia, the free encyclopedia


68 Posts

Specializes in Peds acute, critical care, Urgent Care. Has 5 years experience.

I think about it like compensation. Bradycardia is a late sign, like in shock, if you are compensating, and you start ending up in a bradycardic heart rate, that's BAD news, means the body is failing, or is moments away from failing.