Cardiogenic Shock and Obstructive Shock for Certified Emergency Nursing (CEN)

Reduced cardiac output (CO=SVxHR) can cause a drop in tissue perfusion, and cellular hypoxia. This results in dysregulation of pH, multiorgan failure, and death if not reversed.

Cardiogenic (pump failure)

Cardiomyopathy: heart muscle dysfunction, reduced squeeze, systolic failure, decreased SV
Arrhythmia: tachy can cause decreased SV (reduced filling time); brady results in decreased HR; BBB causes ventricular dyssynchrony and paradoxical septal motion, decreasing SV; atrial arrhythmias lose atrial kick and decrease SV
Mechanical: valvular disease, acute septal rupture or papillary muscle rupture s/p MI

Obstructive (reduced preload)

Pulmonary vascular: right heart strain from PE or pulmonary hypertension. Hypoxia of shock worsens pulmonary vascular resistance.
Mechanical: tension pneumothorax, pericardial tamponade, constrictive pericarditis, restrictive cardiomyopathy

Pathophysiology:

An inadequate tissue perfusion which impairs the ability normal cellular metabolism. Cardiogenic shock specifically is when the heart (or pump) fails to pump out enough blood to meet the oxygen demands on the body.

Valvular heart disease, and acute papillary rupture, and PE put strain on the heart and reduce SV.
Pericardial tamponade and tension pneumothorax
Decreased SV with diastolic HF.

Clinical Presentation:

“Cool and Wet”
Hypotension
Diaphoresis
Dyspnea
Tripoding
Orthopnea (pulmonary congestion)
Pulmonary edema on CXR
Cool extremities (poor perfusion)
Crackles on lung auscultation
Poor appetite, early satiety
Pink frothy sputum
Leg edema
Abdominal edema
Oliguria
Metabolic acidosis
Chest pain?

Collaborative Management:

Labs: BNP, Troponin, CMP
CXR
Echocardiogram: assess ejection fraction, valves, pericardial sac
12 lead EKG
Continuous rhythm monitoring
Freq NIBP vs Invasive hemodynamic monitoring
Diuretics (Furosemide)
Positive inotropes (Digoxin)
Vasopressors (Norepinephrine)
Positive chronotropes if brady (Dopamine)
Cath lab: left and/or right cardiac cath, mechanical support (Impella vs IABP)

Evaluation | Patient Monitoring | Education:

Continuous rhythm monitoring
Freq NIBP vs Invasive hemodynamic monitoring
Continuous oxygen saturation monitoring
Oxygen as needed, possibly intubation vs Bipap
Monitor urine output
Delay patient education until more stable, provide emotional support to patient and family

Linchpins: (Key Points)

Pump problems can originate inside or outside the heart.
CO = HR x SV
The heart must be able to squeeze well and relax well in order to maintain good cardiac output.
Rhythm problems (fast/slow, BBB, AF/AFL) can all have an effect on cardiac output.