9.3 Cardiogenic Shock
Key Takeaways
- Cardiogenic shock is pump failure from STEMI, mechanical complication, myocarditis, cardiomyopathy, or post-arrest stunning—not an empty tank.
- Sort cold versus warm and wet versus dry before you hang fluid; a cold-and-wet left ventricle is not a 30 mL/kg patient.
- Norepinephrine supports coronary perfusion pressure; add dobutamine for a weak squeeze; do not drown the lungs.
- Use NIPPV for flash pulmonary edema if the airway is safe; fly to a PCI-capable or VAD/ECMO center, not the closest clinic (Chapter 15 for devices).
- Cabin hypoxia steals myocardial oxygen supply—raise FiO2 or lower the cabin. Sort right- versus left-sided failure and treat a causative arrhythmia (Chapter 15.2).
Cardiogenic shock is a pump problem: preload may sit in the lungs or neck veins, afterload may be high, or the ventricle may not squeeze, and cardiac output falls. Domain 2.C.2.d of the August 2026 Board of Certification for Emergency Nursing (BCEN) Certified Flight Registered Nurse (CFRN) outline tests cardiogenic shock as the picture you must separate from hypovolemia, obstruction, and distributive collapse before you hang the third liter. Cabin hypoxia makes a dying myocardium worse. Destination is a catheterization laboratory or a mechanical-support center, not the closest clinic.
What failed, and whether the patient is wet or dry
Causes you will actually fly
The pump fails because the muscle is ischemic, inflamed, stretched, stunned, or mechanically disrupted:
- ST-elevation myocardial infarction (STEMI) and mechanical complications: papillary-muscle rupture with acute mitral regurgitation, ventricular septal defect (VSD), or free-wall rupture heading toward tamponade.
- Myocarditis and acute cardiomyopathy, including peripartum and toxic-metabolic pumps.
- Post-arrest myocardial stunning after return of spontaneous circulation that still cannot generate a pressure.
Arrhythmia can be the entire cause—or the thing that tipped a weak pump. Unstable bradycardia, ventricular tachycardia, or new complete heart block is a rhythm problem first. Chapter 15.2 owns the full dysrhythmia lecture; here, ask whether the shock is the rhythm or the muscle.
Cold, warm, wet, and dry
The old Forrester language still sorts the litter. Cold means hypoperfusion: mottled skin, delayed capillary refill, oliguria, rising lactate, a narrow pulse pressure. Warm cardiogenic shock is less common and usually mixed. Wet means congestion: pulmonary edema, froth, high filling pressure. Dry means the pump is empty or the right ventricle is not delivering blood leftward. A cold-and-wet left-ventricular STEMI is not a 30 mL/kg patient. A cold-and-dry right-ventricular infarct or a massive pulmonary embolism (PE) needs careful preload, not a nitroglycerin drip.
| Picture | Typical findings | Flight implication |
|---|---|---|
| Cold and wet (left-sided) | Froth or hypoxia, cool skin, STEMI or known left ventricle (LV) failure | Pressor plus or minus inotrope, noninvasive positive-pressure ventilation (NIPPV) if the airway is safe, no fluid drowning |
| Cold and dry (right-sided or empty) | Clear lungs, distended neck veins if the right ventricle (RV) fails, or flat veins if empty | Small fluid challenges only if the RV looks empty; do not treat PE or RV infarct like wet LV failure |
| Mechanical complication | New murmur, sudden shock days after infarct | Surgical or interventional destination, not another clinic troponin |
| Post-arrest stun | Recent return of spontaneous circulation (ROSC), low output, often wet | Support the pressure; fly toward percutaneous coronary intervention (PCI) and possible mechanical support |
Drugs, ventilation, and what not to pour
Norepinephrine is the usual first pressor for hypotensive cardiogenic shock: it raises mean arterial pressure (MAP) so coronary perfusion pressure returns. Add dobutamine when pressure is just high enough but the pump is still weak. Dobutamine without a pressor can drop systemic vascular resistance (SVR) and dump the MAP. Avoid drowning the patient in fluid. A 250 mL challenge is a test, not a protocol, and only if the lungs are dry and the RV is not already ballooned.
NIPPV (or continuous positive airway pressure (CPAP)) is first-line for flash pulmonary edema when the patient still protects the airway: sit them up, apply the mask, and unload the left ventricle. If they are tiring, vomiting, or losing consciousness, intubate on the ramp. After intubation, do not crush a failing RV with reckless positive end-expiratory pressure (PEEP).
Right versus left failure is a destination and a ventilator decision. Isolated LV failure is wet, hypoxic, and often hypertensive before it is shocked. Isolated RV failure—PE or RV infarct—has clearer lungs, a dilated RV, and an underfilled left ventricle. Fluids and high PEEP that help one picture wreck the other.
Mechanical support, destination, and the cabin
Point to Chapter 15; do not become the device
When drugs cannot restore output, mechanical circulatory support (MCS) is the next conversation: intra-aortic balloon pump (IABP), Impella, or extracorporeal membrane oxygenation (ECMO). Chapter 15 owns transport of those devices. Recognize that the closest clinic cannot start them and call a PCI-capable hospital or a ventricular assist device (VAD) / ECMO center before you lift. Helium-filled balloons and circuit volume are altitude problems; do not accept an IABP patient without a program that knows the timing cable and the helium tank.
Dalton meets the coronary arteries
Dalton's law drops the partial pressure of inspired oxygen (PIO2) as cabin altitude rises. Cabin hypoxia worsens myocardial oxygen supply. Raise fraction of inspired oxygen (FiO2), request a lower cabin, treat anemia if you are carrying blood, and stop pain or shivering that wastes oxygen. A saturation that is acceptable for a young septic patient is not acceptable for an anterior STEMI with a systolic pressure of 78 mm Hg.
- Start norepinephrine for pressure; add dobutamine for a weak squeeze; do not lead with a fluid dump.
- Use NIPPV for flash edema if the airway is safe; intubate on the ground if it is not.
- Sort RV from LV before you pick PEEP, nitroglycerin, or a fluid bolus.
- Treat a causative rhythm (Chapter 15.2) before you blame the muscle.
- Fly to PCI or an MCS center; raise FiO2 and lower the cabin because altitude steals coronary oxygen.
A cool, wet, hypotensive anterior-STEMI patient is packaged for rotor-wing transfer. What is the most appropriate circulatory plan?
A post-arrest cardiogenic-shock patient remains hypotensive on norepinephrine and dobutamine. Which destination is appropriate?
During an unpressurized climb, a wet left-ventricular-failure patient desaturates and a second patient has isolated right-ventricular infarct physiology. Which statement is correct?