Leading Indicators of Shock

[DFIB]

One of the first things I consider when evaluating a patient for shock is the Nature of Illness or the Mechanism of Injury against the probability that either could contribute to provoking shock in my patient.

The obvious differential signs for shock such as heart rate, respiratory rate, and sign of perfusion such as skin color , temperature and mental status aid in the differential diagnosis and point toward shock or discarding the possibility.

There is one sign that I consider heavily when I suspect shock. I notice the mention that BP decrease is a “late” sign for shock.

When I evaluate the BP of a patient I suspect of shock I look heavily at the Pulse pressure.

Considering that blood pressure is the result of the interaction between the cardiac output and the peripheral vascular resistance a narrowing pulse pressure in unison with increased heart rate and presumably a decreased stroke volume makes me suspect hypovolemic shock.

If the heart rate is increased with a decrease in systolic pressure while the diastolic pressure remains relatively stable I suspect a decreased stroke volume and peripheral vasoconstriction which will be evidenced by a narrow pulse pressure.

Almost every shock patient I have attended in my short EMS career has followed this pattern.

(EDIT) I just read the shock index thread. I learned this in EMT B school. The index seems cool but would surely contribute to the dumbing down of EMT. If they are already that way I guess they can use the index.

Edited May 1, 2012 by DFIB

[Asysin2leads]

I think mental status is extremely important, but it can't just be shoehorned into "alert" "confused" or "unresponsive." A little more finesse in assessing the mental status is required. Irritability is a good sign, but you have to rule out the fact that they are not irritated by the attention they are getting. This where it comes in handy to quiet everyone down and defuse the scene. On the other hand, asking a bystander to compare their mental state to their normal state is extremely helpful. If a usually alert person is just having trouble remembering things, that can be an early warning sign. If you think about compensated shock, your body is compensating, that is, your body is engaged in a strenuous activity. Its like bugging someone who is on the treadmill, they generally take a second to snap out of their zone, and even then, they'll have trouble with even simple questions, and they probably are going to be fairly annoyed with you.

Lethargy is also a matter of relativity. If you have an in shape 20 something year old, and they're having trouble holding their head up, that's a big sign of shock. If they get up to walk a few steps and then have trouble catching their breath, that's another big warning sign.

Like assessing someone with dementia, it all comes down to what's different relative to their normal state. That's why numbers aren't really reliable. If you had vitals of BP of 108/64, HR 110, RR 18, with normal skin condition, but had someone who was hanging their head, irritable, and weak, versus someone with the same set who was chipper and ready to be on their way, then you could have someone who is compensating and someone who is fine.

The other big factor is how quickly the symptoms came on. If I was examining a bicyclist who had gone up and over handlebars 10 minutes prior to our arrival, and was showing the beginning signs of shock, I would be much more concerned with rapid transport to the hospital than someone who say had been having nausea and diarrhea for the past 3 days and now had a BP in the crapper and pale, moist skin. Sure, the second one is definitely sick, definitely needs to have a full assessment done and other causalities ruled out, but the first one, if his symptoms are being caused by internal bleeding, he is much more of a priority, because if you've reached Stage I hemmorhagic shock in 10 minutes, you do not have a lot of time to play around.