Rapid fluid resuscitation is the cornerstone of therapy for hypovolemic shock. Fluid should be infused at a rate sufficient to rapidly correct the deficit. If the estimated blood loss is greater than 30% of the total volume (class III), blood replacement is also indicated. In general, a favorable response to fluid replacement therapy includes increased urinary output (at least 0.5ml/kg/hr), improved level of consciousness, increased peripheral perfusion, and changes in vital signs (such as increased BP, increased pulse pressure, and decreased heart rate). Lab values that are important include lactic acid, which is increased if the shock is severe enough to cause anaerobic metabolism, and decreased serum bicarbonate which leads to a negative base deficit. Successful resuscitation in a shock patient will therefore lead to a falling lactate and normalizing pH. Successful resuscitation in a shock patient will therefore lead to a falling lactate (i.e. <2.0mmol/L) and a normalizing pH.
1: Urine output should be at least 0.5ml/kg/hr.
3: Base deficit should be less than 2.
4: Gastric mucosal pH is different than gastric fluid pH, and should be greater than 7.2.
5: Pulse pressure should be greater than 15mmHg.
Mullins R: Management of shock. In Trauma, McGraw Hill, 2000, pp195-232