Page 7 - 2013 AAHA/AAFP Fluid Therapy Guidelines for Dogs and Cats

2013 AAHA/AAFP Fluid Therapy Guidelines for Dogs and Cats

©2013 AAHA

Preanesthetic Fluids and Preparing the Sick Patient y Provide an IV bolus of an isotonic crystalloid such as LRS
Correct fluid and electrolyte abnormalities in the sick patient as (3–10 mL/kg). Repeat once if needed.
much as possible before anesthesia by balancing the need for pre- y If response is inadequate, consider IV administration of a
anesthetic fluid correction with the condition requiring surgery. colloid such as hetastarch. Slowly administer 5–10 mL/kg
For example, patients with uremia benefit from preanesthetic for dogs and 1–5 mL/kg for cats, titrating to effect to
fluid administration. Further, develop a plan for how fluids will minimize the risk of vascular overload (measure BP every
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be used in an anesthesia-related emergency based on individual 3–5 min). Colloids are more likely to increase BP than
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comoribund conditions, such as hypertrophic cardiomyopathy crystalloids. 15
and oliguric/polyuric renal disease. y If response to crystalloid and/or colloid boluses is
inadequate and patient is not hypovolemic, techniques
Monitoring and Responding to Hypotension During Anesthesia other than fluid therapy may be needed (e.g., vasopressors
Blood pressure (BP) is the parameter often used to estimate tis- or, balanced anesthetic techniques). 9
sue perfusion, although its accuracy as an indicator of blood flow y Caution: Do not use hypotonic solutions to correct
is not certain. 11,14,15 Hypotension under anesthesia is a frequent hypovolemia or as a fluid bolus because this can lead to
occurrence, even in healthy anesthetized veterinary patients. hyponatremia and water intoxication.
Assess excessive anesthetic depth first because it is a common
cause of hypotension. 7,16 Exercise caution when using fluid ther- Postanesthetic Fluid Therapy
apy as the sole method to correct anesthesia-related hypotension Postanesthetic fluid administration varies based on intra-anes-
as high rates of fluids can exacerbate complications rather than thetic complications and comorbid conditions. Patients that
prevent them. 10,11 may benefit from fluid therapy after anesthesia include geriatric
If relative hypovolemia due to peripheral vasodilation is con- patients and patients with either renal disease or ongoing fluid
tributing to hypotension in the anesthetized patient, proceed as losses from gastrointestinal disease. Details regarding anesthesia
described in the following list: management may be found in the AAHA Anesthesia Guidelines for
y Decrease anesthetic depth and/or inhalant concentration. Dogs and Cats. 17

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