Do we recognize shock early enough?
How do we prioritize our interventions?
How can we tell whether we’re making our patient better or worse?
 
World wide, shock is a leading cause of morbidity and mortality in children, mostly for failure to recognize or to treat adequately.
So, what is shock?

Simply put, shock is the inadequate delivery of oxygen to your tissues.  That’s it.  Our main focus is on improving our patient’s perfusion.

Oxygen delivery to the tissues depends on cardiac output, hemoglobin concentration, the oxygen saturation of the hemoglobin you have, and the environmental partial pressure of oxygen.
At the bedside, we can measure some of these things, directly or indirectly.  But did you notice that blood pressure is not part of the equation?  The reason for that is that blood pressure is really an indirect proxy for perfusion – it’s not necessary the ultimate goal.
The equation here is a formality:

DO2 = (cardiac output) x [(hemoglobin concentration) x SaO2 x 1.39] + (PaO2  x 0.003)

 
 
Shock CAN be associated with a low blood pressure, but shock is not DEFINED by a low blood pressure.
 
 
Compensated Shock: tachycardia with poor perfusion.  A child compensates for low cardiac output with tachycardia and a increase in systemic vascular resistance.
 
 
Decompensated Shock: frank hypotension, an ominous, pre-arrest phenomenon.
 
Shock is multifactorial, but we need to identify a primary cause to prioritize interventions.
 
 
How they "COHDe": Cardiogenic, Obstructive, Hypovolemic, and Distributive.
 
Cardiogenic Shock
All will present with tachycardia out of proportion to exam, and sometimes with unexplained belly pain, usually due to hepatic congestion.  The typical scenario in myocarditis is a precipitous decline after what seemed like a run-of-the-mill URI.
Cardiogenic shock in children can be from congenital heart disease or from acquired etiologies, such as myocarditis.  Children, like adults, present in cardiogenic shock in any four of the following combinations: warm, cold, wet, or dry.
"Warm and Dry"
A child with heart failure is “warm and dry” when he has heart failure signs (weight gain, mild hepatomegaly), but has enough forward flow that he has not developed pulmonary venous congestion.  A warm and dry presentation is typically early in the course, and presents with tachycardia only.
"Warm and Wet"
If he worsens, he becomes “warm and wet” with pulmonary congestion – you’ll hear crackles and see some respiratory distress.  Infants with a “warm and wet” cardiac presentation sometimes show sacral edema – it is their dependent region, equivalent to peripheral edema as we see in adults with right-sided failure.
“Warm” patients – both warm and dry and warm and wet -- typically have had a slower onset of their symptoms, and time to compensate partially. Cool patients are much sicker.
"Cold and Dry”
A patient with poor cardiac output; he is doing everything he can to compensate with increased peripheral vascular resistance, which will only worsen forward flow.  Children who have a “cold and dry” cardiac presentation may have oliguria, and are often very ill appearing, with altered mental status.
"Cold and Wet"
The sickest of the group, this patient is so clamped down peripherally that it is now hindering forward flow, causing acute congestion, and pulmonary venous back-up.  You will see cool, mottled extremities.
Cardiogenic Shock: Act
Use point-of-care cardiac ultrasound:
Good Squeeze? M-mode to measure fractional shortening of the myocardium or anterior mitral leaflet excursion.
Pericardial Effusion? Get ready to aspirate.
Ventricle Size? Collapsed, Dilated,
Careful with fluids -- patients in cardiogenic shock may need small aliquots, but go quickly to a pressor to support perfusion
Pressor of choice: epinephrine, continuous IV infusion: 0.1 to 1 mcg/kg/minute.  Usual adult starting range will end up being 1 to 10 mcg/min.
Avoid norepinephrine, as it increases systemic vascular resistance, may affect aft