What is the immediate treatment for hypovolemic shock?

Immediate Treatment for Hypovolemic Shock

Begin immediate fluid resuscitation with isotonic crystalloids (0.9% normal saline or balanced crystalloids), administering rapid boluses of 250-1000 mL (or 10-20 mL/kg) and reassessing hemodynamic status after each bolus, while simultaneously identifying and controlling the source of volume loss. 1

Initial Fluid Resuscitation Strategy

First-Line Fluid Choice

• Isotonic crystalloids are the fluid of choice for initial resuscitation, with isotonic saline (0.9% sodium chloride) specifically recommended for hypovolemia 1
• Balanced crystalloids are generally preferred over normal saline to reduce hyperchloremic metabolic acidosis risk, though both are acceptable 1
• In trauma patients with hemorrhagic shock, initiate crystalloid therapy within the first 3 hours of injury 2

Dosing and Administration

• Administer rapid fluid boluses of 250-1000 mL for adults (or 10-20 mL/kg), repeating based on clinical response 1
• For pediatric patients, give boluses up to 20 mL/kg over 5-10 minutes, titrating to reverse hypotension and restore perfusion 2
• Reassess hemodynamic status after each bolus before administering additional fluid 1

Blood Pressure Targets During Resuscitation

Trauma Without Brain Injury

• Target systolic blood pressure of 80-90 mmHg until major bleeding is controlled (permissive hypotension strategy) 2
• This approach minimizes dilutional coagulopathy and prevents exacerbation of bleeding 2

Trauma With Severe Brain Injury

• Maintain mean arterial pressure ≥80 mmHg to ensure adequate cerebral perfusion 2
• Higher blood pressure targets are necessary to prevent secondary brain injury 2

Hemodynamic Assessment and Targets

Parameters to Monitor After Each Bolus

• Heart rate, blood pressure, respiratory rate 1
• Skin perfusion and capillary refill time 1
• Urine output (target >0.5 mL/kg/hr) 1
• Mental status changes 1
• Serum lactate levels (aim for 20% reduction if elevated) 1

Dynamic vs. Static Measures

• Use dynamic measures of fluid responsiveness (e.g., pulse pressure variation, stroke volume variation) rather than static measures like central venous pressure alone 1
• Frequent clinical reassessment is essential to avoid both under-resuscitation and fluid overload 1

Source Control

Simultaneously identify and control the source of volume loss while resuscitating 2:

• Hemorrhage control through direct pressure, tourniquet application, or surgical intervention 2
• For pelvic ring disruption with hemorrhagic shock, perform immediate pelvic ring closure and stabilization 2
• Damage control surgery should be employed in severely injured patients with deep hemorrhagic shock, ongoing bleeding, and coagulopathy 2

Vasopressor Support

When to Initiate

• If hypotension persists despite adequate fluid resuscitation, initiate vasopressor therapy 3
• Blood volume depletion should be corrected as fully as possible before vasopressor administration, but vasopressors can be given concurrently with fluid resuscitation in emergency situations to prevent cerebral or coronary ischemia 3

Norepinephrine Administration

• Dilute 4 mg norepinephrine in 1,000 mL of 5% dextrose solution (4 mcg/mL concentration) 3
• Initial dose: 8-12 mcg/minute (2-3 mL/minute), then titrate to maintain systolic blood pressure 80-100 mmHg 3
• Average maintenance dose: 2-4 mcg/minute (0.5-1 mL/minute) 3
• In previously hypertensive patients, raise blood pressure no higher than 40 mmHg below pre-existing systolic pressure 3

Critical Pitfalls to Avoid

Fluid Selection Errors

• Avoid hypotonic solutions (e.g., Ringer's lactate) in patients with severe head trauma 2
• Do not use hydroxyethyl starches due to increased risk of acute kidney injury and mortality 1
• Avoid administering norepinephrine in saline solution alone; use dextrose-containing solutions 3

Timing and Volume Errors

• Do not delay fluid resuscitation waiting for central venous access in children; begin peripheral inotropic support if needed 2
• Avoid excessive fluid administration that causes hepatomegaly or pulmonary rales; if these develop, initiate inotropic support rather than additional fluids 2
• Do not abruptly withdraw vasopressor infusions; reduce gradually once adequate perfusion is maintained 3

Monitoring Errors

• Do not rely on blood pressure alone in children, as hypotension is a late finding indicating impending cardiovascular collapse 2
• Occult blood volume depletion should always be suspected if high vasopressor doses are required; central venous pressure monitoring is helpful 3