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Cardiogenic Shock Resident Survival Guide
Overview
Causes
FIRE
Diagnosis
Treatment
Do's
Don'ts

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ahmed Zaghw, MBChB. [2]

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.

Boxes in the red signify that an urgent management is needed.

Abbreviations: CBC, complete blood count; CI, cardiac index; CK-MB, creatine kinase MB isoform; CVP, central venous pressure; DC, differential count; ICU, intensive care unit; INR, international normalized ratio; LFT, liver function test; MAP, mean arterial pressure; MVO2, mixed venous oxygen saturation; PCWP, pulmonary capillary wedge pressure; PT, prothrombin time; PTT, partial prothrombin time; SaO2, arterial oxygen saturation; SBP, systolic blood pressure; ScvO2, central venous oxygen saturation; SMA-7, sequential multiple analysis-7.

Does the patient have cardinal findings that increase the pretest probability of cardiogenic shock? ❑  Evidence of end-organ hypoperfusion ❑  Altered mental status ❑  Cold extremities ❑  Cyanosis ❑  Oliguria (urine output <0.5 mL/kg/h) ❑  Sustained hypotension ❑  SBP <90 mm Hg for ≥30 min or ❑  MAP ↓ >30 mm Hg below baseline for ≥30 min ❑  Presence of myocardial dysfunction after exclusion or correction of non-myocardial factors contributing to tissue hypoperfusion

YES

NO

Cardiogenic shock suspected

Proceed to shock resident survival guide

Immediate management ❑  ECG monitor ❑  Pulse oximeter ❑  Arterial blood gas ❑  Intubation with mechanical ventilation ❑  Large-bore peripheral venous lines ❑  Arterial line ❑  Central venous catheter ❑  Pulmonary artery catheter ❑  Foley catheter ❑  ICU admission ❑  Cardiology consultation ❑  Hold antihypertensive medications

Immediate workup ❑  CBC/DC/SMA-7/LFT/PT/PTT/INR ❑  Cardiac troponins, CK-MB ❑  BNP, NT-proBNP ❑  Lactate ❑  12-Lead ECG ❑  Chest radiograph ❑  Echocardiography

Cardiogenic shock confirmed (click for details on criteria)

Hemodynamic optimization

Preload (click for details) ❑  Goal: PCWP 15–18 mm Hg, CVP 8–12 cm H2O ❑  Fluid challenge protocol ❑  ± Correct pulmonary congestion ❑  ± Furosemide 40 mg slow IV injection ❑  ± Morphine 2–4 mg slow IV injection

Afterload (click for details) ❑  Goal: MAP >60 mm Hg, SVR 800–1200 dyn·s·cm−5 ❑  If ↑ MAP & ↑ SVR: wean vasopressors ± vasodilators ❑  If ↓ MAP & ↑ SVR: vasopressors + inotropes ❑  If ↓ MAP & ↓ SVR: vasopressors ± vasopressin

Cardiac index (click for details) ❑  Goal: CI >2.2 L/min/m2 ❑  ± Dobutamine ❑  ± Milrinone ❑  ± IABP, VAD, or ECMO if refractory

Immediate goals ❑  SaO2 >90%–92% ❑  MVO2 >60% ❑  ScvO2 >70% ❑  Urine output >0.5 mL/kg/h ❑  Lactate <2.2 mM/L ❑  Hemoglobin >7–9 g/dL ❑  ± Correct arrhythmia ❑  ± Correct electrolyte disturbance

Acute myocardial infarction likely? (click for details) ❑  Positive cardiac biomarkers (cTnT, cTnI, or CK-MB) ❑  Symptoms of myocaridal ischemia ❑  New significant ECG findings of myocardial ischemia

YES, then manage as UA/NSTEMI and proceed to acute ischemia pathway

No, then proceed to complete diagnostic approach

Do's

Criteria for Cardiogenic Shock [Return to FIRE]

• Clinical Criteria

• Sustained hypotension (SBP <90 mm Hg or MAP 30 mm Hg below baseline in preexisting hypertension for at least 30 minutes)
• Evidence of tissue hypoperfusion (such as oliguria, cyanosis, cool extremities, and altered mental status)
• Presence of myocardial dysfunction after exclusion or correction of non-myocardial factors contributing to tissue hypoperfusion (such as hypovolemia, hypoxia, and acidosis)

• Hemodynamic Criteria

• Sustained hypotension (SBP <90 mm Hg or MAP 30 mm Hg below baseline in preexisting hypertension for at least 30 minutes)
• Depressed cardiac index (<1.8 L/min/m² of BSA without support or <2.0–2.2 L/min/m² of BSA with support) in the presence of an elevated wedge pressure (>15 mm Hg).

Hemodynamic Optimization

Preload [Return to FIRE]

• Preload manipulation includes quantitative assessment of response to fluid challenge protocol, maintenance of PCWP and CVP levels, and minimize or correct pulmonary congestion.

Fluid Challenge Protocol

• 1. Type of fluid

• The choice of crystalloid or colloid solution should be made on the basis of the underlying disease, the nature of fluid deficit, the severity of circulatory failure, the serum albumin concentration, and the risk of bleeding.

• 2. Rate of infusion

• Based on the baseline of central venous pressure or pulmonary capillary wedge pressure, a volume of 50, 100, or 200 ml of fluid is administered over a 10-minute interval through a peripheral venous catheter.

• 3. Clinical end points

• Fluid challenge with predetermined boluses should be titrated to reach hemodynamic and clinical endpoints.
• Vasopressors, inotropes, mechanical circulatory assistance, or ECMO may be considered if end-organ hypoperfusion persists despite adequate ventricular filling pressure.

• 4. Pressure safety limits

• Norepinephrine

• Dosage and Administration

• Mix 1 ampule (4 mg) of norepinephrine in 250 mL of D5W or D5NS. Avoid dilution in normal saline alone.
• Initial dose: 0.5–1.0 μg/min IV infusion; titrate to maintain SBP at above 90 mm Hg (up to 30–40 μg/min).

• Contraindications

• Norepinephrine should not be given to patients who are hypotensive from blood volume deficits except as an emergency measure to maintain coronary and cerebral artery perfusion until blood volume replacement therapy can be completed.
• Norepinephrine should also not be given to patients with mesenteric or peripheral vascular thrombosis unless it is necessary as a life-saving procedure.

Pulmonary Congestion

• Radiologic manifestations of pulmonary congestion reflect the extent of elevation in wedge pressure:

PCWP (mm Hg)	Phase of Pulmonary Congestion	Findings on Chest Radiograph
18–20	Onset of pulmonary congestion	Redistribution of pulmonary flow to the upper lobes ("cephalization") and Kerley lines
20–25	Moderate congestion	Diminished clarity of the borders of medium-sized pulmonary vessels ("perihilar haze")
25–30	Severe congestion	Radiolucent grapelike clusters surrounded by radiodense fluid ("periacinar rosette")
>30	Onset of pulmonary edema	Coalescence of periacinar rosettes resulting in "Bat's wing" opacities

• Furosemide

• Dosage and Administration

• For acute pulmonary edema, the initial dose is 40 mg injected slowly intravenously (over 1 to 2 minutes).
• If a satisfactory response does not occur within 1 hour, the dose may be increased to 80 mg injected slowly intravenously (over 1 to 2 minutes).

• Contraindications

• Anuria
• Hypersensitivity to furosemide

• Morphine

• Dosage and Administration

• Slow IV injection 2–4 mg (over 1–5 minutes) every 5–30 minutes as needed.

• Contraindications

• Hypersensitivity to morphine sulfate is one of the contraindications to its use.
• Morphine should not be used in convulsive states, such as those occurring in status epilepticus, tetanus, and strychnine poisoning.
• Morphine is also contraindicated in the following conditions: respiratory insufficiency or depression; bronchial asthma; heart failure secondary to chronic lung disease; cardiac arrhythmias; increased intracranial or cerebrospinal pressure; head injuries; brain tumor; acute alcoholism; and delirium tremens.

Afterload [Return to FIRE]

Cardiac Index [Return to FIRE]

Criteria for Acute Myocardial Infarction [Return to FIRE]

• Detection of a rise and/or fall of cardiac biomarker values (preferably cardiac troponin) with at least one value above the 99th percentile upper reference limit and with at least one of the following:

• Symptoms of ischemia
• New or presumably new significant ST-segment–T wave (ST–T) changes or new left bundle branch block (LBBB).
• Development of pathological Q waves in the ECG.
• Imaging evidence of new loss of viable myocardium or new region wall motion abnormality.
• Identification of an intracoronary thrombus by angiography or autopsy.

References