What are the best fluids to use in a patient with septic shock?

Best Fluids for Septic Shock

Crystalloids are the fluid of choice for initial resuscitation in septic shock, with balanced crystalloids (lactated Ringer's or Plasma-Lyte) preferred over normal saline when available, and you should administer at least 30 mL/kg within the first 3 hours. 1, 2

Initial Fluid Selection

Use crystalloids as your first-line resuscitation fluid with strong evidence supporting this approach over colloids for initial management 3, 2. The Surviving Sepsis Campaign provides a strong recommendation for crystalloids based on moderate quality evidence 3, 2.

Balanced Crystalloids vs. Normal Saline

• Prefer balanced crystalloids (lactated Ringer's or Plasma-Lyte) over normal saline to reduce the risk of hyperchloremic metabolic acidosis 1
• Normal saline causes hyperchloremic metabolic acidosis and is associated with increased risk of acute kidney injury progression, particularly in patients with pre-existing AKI 1
• While guidelines suggest either balanced crystalloids or saline can be used, the evidence increasingly favors balanced solutions 3, 1

Volume and Timing

Administer at least 30 mL/kg of crystalloid within the first 3 hours of recognizing sepsis-induced hypoperfusion or septic shock 3, 1, 2. This is a strong recommendation based on moderate quality evidence 1, 2.

Important Nuances About Volume

• Some patients may require more rapid administration and greater amounts beyond the initial 30 mL/kg 3, 2
• Recent observational data suggests that 20-30 mL/kg within the first hour may be associated with lower mortality compared to higher volumes (>30 mL/kg), though this requires confirmation in randomized trials 4
• Continue fluid administration as long as hemodynamic parameters continue to improve, using dynamic measures (pulse pressure variation, stroke volume variation) or static variables (arterial pressure, heart rate, urine output, mental status) 3, 1, 2

When to Add Albumin

Consider adding albumin to crystalloids when patients require substantial amounts of crystalloids for ongoing resuscitation 3, 2. This is a weak recommendation based on low quality evidence, meaning albumin is not first-line but can be used as an adjunct when crystalloid requirements are high 3.

Fluids to Absolutely Avoid

Never use hydroxyethyl starches (HES) for resuscitation in septic shock - this is a strong recommendation based on high quality evidence showing increased mortality and acute kidney injury 3, 1, 2, 5.

Avoid gelatins - guidelines suggest using crystalloids over gelatins, though this is a weaker recommendation 3.

Reassessment and Ongoing Management

Following initial resuscitation, guide additional fluids by frequent reassessment of hemodynamic status 3, 2. Your reassessment should include:

• Heart rate, blood pressure, arterial oxygen saturation 2
• Respiratory rate, temperature, urine output 2
• Mental status and peripheral perfusion 2
• Dynamic measures of fluid responsiveness are preferred over static measures like central venous pressure where available 3, 2

Stop fluid administration when no improvement in tissue perfusion occurs, signs of fluid overload develop, or hemodynamic parameters stabilize 1.

Critical Pitfalls to Avoid

• Do not delay resuscitation due to concerns about fluid overload - delayed resuscitation increases mortality 1
• Do not rely solely on central venous pressure (CVP) to guide fluid therapy as it has poor predictive ability for fluid responsiveness 1
• Do not use low-dose dopamine for renal protection - it is ineffective 1

When to Initiate Vasopressors

If hypotension persists despite adequate fluid resuscitation, initiate norepinephrine as the first-choice vasopressor, targeting a mean arterial pressure of 65 mmHg 3, 1, 2. This is a strong recommendation based on moderate quality evidence 2.