Initial Assessment and Treatment for Suspected Hypovolemia
Begin immediate fluid resuscitation with isotonic crystalloids at 20 mL/kg (adults) or 10-20 mL/kg (pediatrics) as a rapid bolus while simultaneously assessing clinical markers of hypoperfusion. 1, 2
Clinical Assessment of Hypovolemia
Physical Examination Findings
- Assess capillary refill time (prolonged >2 seconds indicates hypoperfusion) 1
- Evaluate extremity temperature (cold peripheries suggest poor perfusion) 1
- Check mental status (altered consciousness indicates cerebral hypoperfusion) 1
- Monitor urine output (oliguria <0.5 mL/kg/h suggests inadequate renal perfusion) 1
- Examine pulse quality (weak peripheral pulses with strong central pulses indicate shock) 1
Hemodynamic Parameters
- Measure blood pressure and heart rate (tachycardia with hypotension are cardinal signs) 1
- Target mean arterial pressure ≥65 mmHg as initial resuscitation goal 2
- Obtain serum lactate when available as a marker of tissue hypoperfusion severity 1
Dynamic Assessment
- Perform passive leg raising test in spontaneously breathing patients: an increase in cardiac output or stroke volume ≥12% during leg elevation predicts fluid responsiveness with 89% specificity 3
Initial Fluid Resuscitation
Crystalloid Administration (First-Line)
Isotonic crystalloids are the definitive first choice for initial resuscitation. 2
- Adults: Administer 500-1000 mL boluses over 30 minutes, or minimum 30 mL/kg in first hour for sepsis-induced hypoperfusion 2, 1
- Pediatrics: Give 10-20 mL/kg boluses over 5-10 minutes 2, 1
- Preferred solution: Balanced crystalloids (Ringer's lactate) or normal saline are equivalent 2, 1
Fluid Challenge Technique
- Continue fluid boluses as long as hemodynamic parameters improve (blood pressure, heart rate, capillary refill, mental status, urine output) 2, 1
- Reassess after each bolus rather than administering predetermined volumes blindly 1
- Monitor for fluid overload signs: hepatomegaly, pulmonary crackles, jugular venous distension 1
Colloid Considerations
When to Consider Albumin
- Add albumin only when patients require substantial amounts of crystalloids (typically >30-60 mL/kg) to maintain adequate blood pressure 2
- This is a weak recommendation based on low-quality evidence 2
Avoid Hydroxyethyl Starches
Do not use hydroxyethyl starch solutions for hypovolemia resuscitation due to increased mortality risk in septic patients 2
Monitoring Resuscitation Adequacy
Target Endpoints
- Capillary refill time <2 seconds 1
- Warm extremities 1
- Normal mental status 1
- Urine output >0.5 mL/kg/h (adults) or >1 mL/kg/h (children) 1
- Normalized heart rate and blood pressure for age 1
- Lactate clearance (decreasing levels indicate improved perfusion) 1
Signs of Adequate Resuscitation
- No difference between central and peripheral pulse quality 1
- Resolution of tachycardia 1
- Improved consciousness 1
Vasopressor Initiation
When Fluids Are Insufficient
If hypotension persists despite adequate fluid resuscitation (typically after 30-60 mL/kg crystalloids), initiate vasopressor support. 2, 1
- Norepinephrine is the first-choice vasopressor to target MAP ≥65 mmHg 2, 4
- Peripheral vasopressor administration is acceptable while obtaining central access 1
- Epinephrine is second-line when additional agent needed 2
Critical Caveat
Blood volume depletion must be corrected as fully as possible before vasopressor administration, though vasopressors can be given concurrently with ongoing fluid resuscitation in emergency situations to prevent cerebral or coronary ischemia 4
Common Pitfalls to Avoid
Fluid Overload
- Excessive fluid administration without response assessment leads to pulmonary edema and organ dysfunction 1, 5, 6
- Reduce infusion rate immediately if overload signs appear and consider inotropic support 1
Inadequate Initial Resuscitation
- Failure to give adequate initial fluid boluses (minimum 20-30 mL/kg) results in persistent hypoperfusion 2, 1
- Delayed recognition of ongoing fluid losses (hemorrhage, third-spacing) perpetuates shock 4