| Domain | Bedside questions |
|---|---|
| Perfusion | Mentation, skin temperature, capillary refill, urine output, lactate trend and renal/hepatic injury. Does support improve organ function? |
| Pressure and flow | Blood pressure, pulse pressure, rhythm, cardiac output and response to treatment. A higher MAP alone can conceal persistently poor flow. |
| Congestion | JVP, edema, lung ultrasound, oxygen requirement and LV/RV filling. A congested patient can still have inadequate forward output. |
| Cause and trajectory | Acute MI, acute-on-chronic HF, myocarditis, arrhythmia, valve/mechanical disease or mixed vasoplegia. Record the direction of change and support needed. |
Classify severity serially rather than treating a single lactate or cardiac-index value as the whole syndrome.
| Stage | Working interpretation |
|---|---|
| A · At risk | Risk factors for shock without current shock. |
| B · Beginning | Hemodynamic instability without hypoperfusion. |
| C · Classic | Hypoperfusion requiring an intervention beyond simple volume replacement. |
| D · Deteriorating | Initial support is insufficient and escalation is needed. |
| E · Extremis | Circulatory collapse or imminent collapse despite intensive resuscitation. |
Document the arrest context and neurologic uncertainty separately. Stage describes severity and treatment response, not automatic device eligibility or an individual prognosis.
Early echo should look for LV and RV dysfunction, tamponade, acute severe valve disease and post-MI mechanical complications. Coronary evaluation and definitive treatment of a reversible cause should not be delayed by a search for a perfect hemodynamic profile.
| Phenotype | Interpretation and reassessment |
|---|---|
| LV dominant | Pulmonary congestion and impaired systemic flow. Reassess afterload, ischemia, valve lesions and LV unloading needs. |
| RV dominant | High right-sided pressure with limited LV filling. Assess RV ischemia, pulmonary vascular load, ventilation, rhythm and septal interaction. |
| Biventricular | Both filling-pressure compartments and organ perfusion are abnormal. An isolated LV device may not correct the whole circulation. |
| Mixed shock | Low output with vasodilation, infection or post-arrest inflammation. Address both cardiac performance and vascular tone. |
| Underfilled | Confirm that low filling is real before fluid. Reassess after small, monitored interventions rather than giving blind volume into congestion. |
CPO = MAP × cardiac output / 451 in watts. It combines pressure and flow. PAPi = (PA systolic − PA diastolic pressure) / right atrial pressure. It is affected by loading conditions, pulmonary vascular disease, ventilation and measurement technique.
Repeat questionable waveforms and reconcile measured output with oxygen saturations and the bedside examination. Use the hemodynamics guide for acquisition and waveform interpretation.
When a vasopressor is needed, norepinephrine is commonly favored over dopamine and often over epinephrine because of arrhythmia and metabolic concerns. Add an inotrope selectively for persistent low output after pressure and filling assessment. Dobutamine and milrinone have different kinetic, renal and vascular effects.
| Evidence | Finding and boundary |
|---|---|
| CULPRIT-SHOCK | In AMI shock with multivessel disease, initial culprit-only PCI reduced the composite of death or renal-replacement therapy compared with immediate multivessel PCI. This does not mean ignoring later nonculprit disease. |
| IABP-SHOCK II | Routine IABP did not reduce mortality in AMI shock treated with early revascularization. This does not settle every bridge or mechanical-complication use. |
| DanGer-Shock | Selected STEMI-shock patients had lower 180-day mortality with a microaxial flow pump, with more adverse events. Selection and exclusions matter. Do not generalize to all shock, severe RV failure or comatose arrest. |
| ECLS-SHOCK / ECMO-CS | Routine early VA-ECMO strategies did not establish a broad survival advantage and introduce substantial complication burden. Rescue decisions remain individualized. |
Decide whether the unmet need is LV support, RV support, biventricular support, oxygenation or a bridge through a reversible lesion. Document bleeding, limb ischemia, stroke, hemolysis, infection and ventricular-loading risks before and during support.
Related guides: Impella, VA-ECMO, RV/BiV support and IABP.
Worsening perfusion, rising support needs, persistent lactate elevation, new organ injury or uncertainty about the phenotype should trigger multidisciplinary reassessment and consideration of transfer to a capable center. A serial SCAI stage makes deterioration visible.
| Reassessment | Decision to record |
|---|---|
| Has the cause been treated? | Revascularization, rhythm control, correction of a valve/mechanical lesion or disease-specific treatment. |
| Is support achieving its goal? | Perfusion and organ recovery, ventricular unloading, oxygenation and reduced vasoactive need. |
| Is treatment creating harm? | Bleeding, hemolysis, limb/mesenteric ischemia, neurologic injury, infection or worsening ventricular distension. |
| Is the exit still feasible? | Recovery and weaning, durable LVAD, transplantation, another temporary configuration or a goal-concordant limit. |
For prolonged support dependence, integrate hemodynamics, end-organ reversibility, neurologic information, frailty, RV reserve and patient goals. A device buys time but does not itself establish candidacy.
Use one coordinated plan with named clinical responsibility. Explain uncertainty and the next decision to the patient and family. Palliative care can support symptoms and decision-making alongside recovery, transplant or device treatment.