Fluid Therapy

If the patient has hypovolemic or distributive shock, the team should ensure the rapid administration of IV fluids to restore intravascular volume and tissue perfusion. However, if shock is secondary to a cardiogenic or obstructive etiology, fluid therapy should be provided only when necessary. Aggressive fluid therapy can worsen pulmonary edema in cardiogenic and obstructive shock.

Intravenous Fluid

Isotonic crystalloid solutions (normal saline or lactated Ringer) are the most common fluids used in the treatment of shock. They can expand intravascular volume appropriately. The clinician should consider blood and other blood products if the patient has a hemorrhage or certain coagulopathies.

A child receives IV fluids.

Colloid solutions (5% albumin and fresh frozen plasma) can be secondary alternatives for volume expansion in shock. A significant disadvantage is that they may be difficult to obtain and can cause sensitivity to the product. Colloids can also cause coagulopathies and worsen pulmonary edema. In the presence of extensive bleeding from trauma, clinicians may opt to transfuse fresh frozen plasma administered at 20–40 mL/kg.

Fluid Administration Guidelines

Patients with hypovolemic shock are given 20 mL/kg of isotonic crystalloid solution administered as an IV bolus over 5–20 minutes. The fluid bolus may be repeated as needed based on clinical examination and estimates of fluid loss.

Fluid overload during treatment for septic shock increases morbidity rates. Providers should use their best clinical judgment to determine if fluid bolus volumes should be 10 mL/kg or 20 mL/kg.

Cardiogenic or obstructive shock requires the administration of less fluid at a slower rate. Volumes of 5–10 mL/kg can be delivered over 20 minutes. The child should be reassessed after each bolus for impending respiratory distress, crackles, or signs of hepatomegaly and pulmonary edema. If pulmonary edema ensues, the team must provide immediate respiratory support by maintaining an airway, giving oxygen, and assisting ventilation with PEEP.

In children with diabetic ketoacidosis, increased serum osmolality caused by hyperglycemia imposes a risk for cerebral edema, which increases with excessive fluid therapy. The provider should administer an isotonic crystalloid of 10–20 mL/kg over 2 hours. If the patient in DKA has concurrent hypovolemic or hypotensive shock, more aggressive fluid therapy may be necessary to prevent cardiopulmonary failure and eventual arrest. Ultimately, expert consultation is required.

Toxicity from calcium channel blockers or β-adrenergic blockers can cause myocardial dysfunction, which is sensitive to the rapid administration of intravenous therapies. Children with severe febrile illnesses are also sensitive to rapid fluid therapy.

Recommended Fluid Therapies in Shock

Recommended Fluid Therapies in Shock

Rapid Fluid Delivery

Rapid delivery of IV fluids requires a large catheter, especially if the team needs to administer blood products. The provider should insert two catheters of the largest feasible size with 3-way stopcocks. The fluid bolus can be delivered through a 30 or 60 mL syringe connected to the stopcock. A pressure bag can also be used for rapid infusion instead of the syringe.

Related Video -How to Use a 3-Way Stop Cock

In the event an IV cannula cannot be inserted, IO access is the next best solution. 

Ordinary infusion pumps cannot deliver rapid IV infusions, especially in larger pediatric patients. Standard infusion pumps are designed to provide a maximum rate of 999 mL every hour.

Related Video – One Quick Question: What is the 421 Formula

Reassess After Each Administration of IV Fluid Therapy

After giving the IV fluid, the patient is reassessed for their response to the therapy to determine if there is a need for further fluid boluses. Improved perfusion, an increase in blood pressure, improved urine output, and improving mental status are positive signs. 

Worsening mental status, further hypotension, or decreased perfusion are concerning. The provider must then reassess the patient for the type of shock and treat accordingly. The child should also be assessed for complications of fluid therapy, such as pulmonary edema.

Blood Product Therapies

Packed RBCs can be used for traumatic blood loss, especially when there are signs of inadequate perfusion after 2 to 3 fluid boluses of 20 mL/kg. The recommended dose of packed RBCs is 10 mL/kg. 

Fully cross-matched blood products are preferred, but in emergencies, cross-matching may take too long. In that case, it is common to use unmatched, type-specific blood products when there is ongoing blood loss that causes poor perfusion and hypotension despite the administration of the crystalloid solution. Type-specific blood products may have other antibodies that are incompatible with the patient’s blood and may cause a reaction.

If type-specific blood cannot be available within 10 minutes, the child should be immediately transfused with type-O blood to prevent circulatory collapse and cardiac arrest. Rh sensitization is a concern, so female patients should receive type O-negative to prevent any pregnancy-related ABO incompatibility issues in the future.

Complications Arising From Rapid Administration of Blood Products

Rapid administration of blood products may cause complications such as hypothermia, myocardial dysfunction, and ionized hypocalcemia. Hypothermia impairs cardiovascular function, affects coagulation, and compromises metabolic functions, including the metabolism of citrate. 

Citrate is part of the transfused blood product. If the body does not metabolize citrate, the patient’s serum ionized calcium levels will decrease. Ionized hypocalcemia can lead to myocardial dysfunction, further worsening shock.