What is the approach to volume resuscitation in severe hypovolemia (low blood volume)?

From the Guidelines

Volume resuscitation in severe hypovolemia requires immediate administration of balanced crystalloid fluids, such as Lactated Ringer's solution, at an initial bolus of 20-30 mL/kg given rapidly over 5-15 minutes, as this approach has been associated with reduced mortality in critically ill patients 1. The choice of fluid is crucial, and balanced crystalloids are preferred over saline due to their more physiological composition, which may reduce the risk of hyperchloremic metabolic acidosis and kidney injury. Key points to consider in volume resuscitation include:

• Initial bolus of 20-30 mL/kg of balanced crystalloid fluids
• Reassessment after each bolus for signs of improved perfusion, including heart rate, blood pressure, capillary refill, urine output, and mental status
• Additional boluses should be given if the patient remains hypotensive or shows continued signs of hypoperfusion
• In trauma or hemorrhagic shock, blood products should be initiated early, with packed red blood cells given in a 1:1:1 ratio with fresh frozen plasma and platelets if massive transfusion is needed
• Vasopressors like norepinephrine may be necessary if hypotension persists despite adequate volume replacement, but should not be used as a substitute for appropriate fluid resuscitation The goal of volume resuscitation is to restore tissue perfusion while avoiding fluid overload, targeting a mean arterial pressure of at least 65 mmHg, normalization of heart rate, improved mental status, and urine output >0.5 mL/kg/hr, as recommended by recent guidelines 1. Rapid fluid administration helps restore intravascular volume, cardiac output, and tissue perfusion, preventing the progression to irreversible shock and multi-organ failure. It is essential to note that the use of hydroxyethyl starches is not recommended for fluid resuscitation in severe sepsis and septic shock due to their association with increased mortality and kidney injury 1. In contrast, albumin may be considered in the fluid resuscitation of severe sepsis and septic shock when patients require substantial amounts of crystalloids 1. Overall, the choice of fluid and the approach to volume resuscitation should be guided by the most recent and highest-quality evidence, with the goal of improving patient outcomes and reducing morbidity and mortality.

From the FDA Drug Label

6% Hetastarch in 0.9% Sodium Chloride Injection is indicated in the treatment of hypovolemia when plasma volume expansion is desired. 6% Hetastarch in 0.9% Sodium Chloride Injection is a hetastarch indicated for treatment of hypovolemia when plasma volume expansion is desired.

Volume Resuscitation in Severe Hypovolemia:

• Hydroxyethyl starch (IV) can be used for volume resuscitation in severe hypovolemia when plasma volume expansion is desired 2, 2.
• However, it is not recommended for use in critically ill adult patients, including patients with sepsis, due to increased risk of mortality and renal replacement therapy (RRT) 2.
• It is also contraindicated in patients with severe liver disease, known hypersensitivity to hydroxyethyl starch, clinical conditions where volume overload is a potential problem, and pre-existing coagulation or bleeding disorders 2.

From the Research

Volume Resuscitation in Severe Hypovolemia

• The primary goal of volume resuscitation in severe hypovolemia is to restore blood volume and ensure adequate perfusion of vital organs 3, 4, 5.
• The choice of resuscitation fluid is crucial, with crystalloids being the preferred option over colloids due to their lower risk of adverse effects and cost 3, 4, 6.
• Among crystalloids, balanced solutions such as Lactated Ringer's are recommended over normal saline due to their lower risk of hyperchloremic metabolic acidosis and renal vasoconstriction 3, 4.
• However, Lactated Ringer's should not be used in patients with severe metabolic alkalosis, lactic acidosis with decreased lactate clearance, or severe hyperkalemia, and in patients with traumatic brain injury or at risk of increased intracranial pressure 3.
• The optimal choice of infusate should be guided by the cause of hypovolemia, the cardiovascular state of the patient, the renal function, as well as the serum osmolality and the coexisting acid-base and electrolyte disorders 3, 4.
• A multifaceted approach to diagnosing and treating hypovolemia is recommended, including medical history, physical examination, volume responsiveness, and technical parameters such as dynamic indicators, volumetric indicators, sonography, and metabolic indicators 4.
• Early aggressive fluid therapy is still beneficial in septic shock resuscitation, despite recent trials challenging the early goal-directed therapy (EGDT) concept 4, 5.
• A conservative, physiologically guided approach to fluid resuscitation is likely to improve patient outcomes, and the approach to fluid therapy must be individualized based on the cause of shock as well as the patient's major diagnosis, comorbidities, and hemodynamic and respiratory status 5, 6.
• Recent studies have shown that colloids, whether individually or in hypertonic crystalloids, have no mortality benefit over crystalloids in adult patients with hypovolemic shock 7.