How to manage a patient with cardiac dysfunction and suspected sepsis?

Management of Cardiac Dysfunction in Sepsis

Patients with sepsis and cardiac dysfunction require prompt evaluation with bedside cardiac ultrasonography (BCU) to guide fluid resuscitation, vasopressor, and inotropic therapy based on the specific type of cardiac dysfunction present.

Initial Assessment and Diagnosis

• Immediate diagnostic workup:

  • Bedside cardiac ultrasonography (BCU) within 48 hours (immediately if hemodynamically unstable) 1
  • 12-lead ECG 1
  • Chest X-ray to assess pulmonary congestion 1
  • Laboratory tests: cardiac troponins, BUN/creatinine, electrolytes, glucose, complete blood count, liver function tests, and TSH 1
  • Blood cultures (before antibiotics if no substantial delay) 2
  • Plasma natriuretic peptide levels (BNP or NT-proBNP) 1

• Cardiac dysfunction patterns to identify on BCU:

  • Left ventricular (LV) dysfunction: occurs in up to 60% of septic patients 1
  • Right ventricular (RV) dysfunction: occurs in up to 30% of septic patients 1
  • Takotsubo cardiomyopathy (apical ballooning syndrome) 1

Management Algorithm

Step 1: Initial Resuscitation (First 3 Hours)

• Administer broad-spectrum antibiotics within 1 hour of sepsis recognition 2
• Provide fluid resuscitation with crystalloids at ≥30 mL/kg within first 3 hours 2
• Target hemodynamic parameters:
  • Mean arterial pressure (MAP) ≥65 mmHg
  • Central venous pressure 8-12 mmHg
  • Urinary output ≥0.5 mL/kg/hr
  • Central venous oxygen saturation ≥70% 2

Step 2: Guided Management Based on BCU Findings

If LV Dysfunction Present:

1. Fluid management:

   • Use fluid challenge technique where fluid administration continues only as long as hemodynamic parameters improve 2
   • Avoid excessive fluid administration in the presence of LV dysfunction as it may aggravate adverse consequences 1
   • Consider balanced crystalloids over normal saline 2

2. Vasopressor support:

   • Initiate norepinephrine as first-line vasopressor to maintain MAP ≥65 mmHg 1
   • Consider adding vasopressin (up to 0.03 U/min) to either raise MAP or decrease norepinephrine dosage 1

3. Inotropic support:

   • Add dobutamine (up to 20 μg/kg/min) if persistent hypoperfusion despite adequate fluid loading and vasopressors 1, 3
   • Titrate to end point reflecting improved perfusion; reduce or discontinue if worsening hypotension or arrhythmias 1

If RV Dysfunction Present:

1. Fluid management:

   • Carefully optimize preload as both inadequate and excessive volume can worsen RV function 1
   • Monitor for signs of RV overload (distended jugular veins, increasing CVP without improved cardiac output)

2. Vasopressor support:

   • Use norepinephrine as first-line agent 1
   • Avoid excessive increases in pulmonary vascular resistance

3. Ventilation strategy:

   • Use low tidal volume ventilation (6 mL/kg predicted body weight) 2
   • Maintain plateau pressure ≤30 cm H₂O 2
   • Apply appropriate PEEP to prevent alveolar collapse 2

Step 3: Ongoing Monitoring and Adjustments

• Reassess cardiac function with repeat BCU as clinical status changes
• Monitor for improvement or deterioration in cardiac function
• Adjust fluid, vasopressor, and inotrope therapy based on:
  • Serial BCU findings
  • Clinical parameters (MAP, heart rate, urine output)
  • Laboratory values (lactate clearance, ScvO2)

Special Considerations

Sepsis-Induced Cardiomyopathy

• Characterized by decreased contractility, impaired ventricular response to fluid therapy, and ventricular dilatation 4
• Usually reversible within 7-10 days in survivors 5
• Mechanisms include:
  • Attenuation of adrenergic response at cardiomyocyte level
  • Alterations in intracellular calcium trafficking
  • Blunted calcium sensitivity of contractile proteins 3
  • Mitochondrial dysfunction and energy mismanagement 6

Prognostic Indicators

• Mitral annular plane systolic excursion (MAPSE) is a good predictor of mortality 5
• Early reduction in cardiac output (within first hours) predicts higher mortality 7
• Myocardial strain measurements provide sensitive detection of early cardiac dysfunction 7

Common Pitfalls to Avoid

1. Excessive fluid administration in patients with cardiac dysfunction, which can worsen pulmonary edema and organ perfusion
2. Delayed recognition of cardiac dysfunction, leading to inappropriate fluid management
3. Overreliance on static measures (like ejection fraction) rather than dynamic parameters of cardiac function
4. Prolonged high-dose catecholamine administration, which may be harmful despite initial benefits 3
5. Failure to reassess cardiac function as sepsis evolves

By following this approach with early BCU evaluation and tailored management based on the specific type of cardiac dysfunction, outcomes in patients with sepsis and cardiac dysfunction can be optimized.