Updates in Perioperative Fluid Therapy

What is the most important reason to provide fluid therapy during general anaesthesia for all animals?
Maintenance of IV catheter patency
Avoidance of hypokalaemia
Avoidance of metabolic acidosis
Maintenance of oxygen delivery to vital tissues
To increase clinic revenue
Venous return is NOT determined by:
Central venous pressure
Heart rate
Total blood volume
Vascular resistance
Mean capillary filling pressure
Which animals do NOT require peri-operative fluids?
Dogs under 8 years of age
Cats under 8 years of age
Healthy, non-geriatric dogs and cats undergoing anaesthesia of less than 30 minutes duration
Healthy, non-geriatric dogs and cats undergoing anaesthesia of up to 2 hours duration
Animals with normal blood pressure during anaesthesia
Even in young healthy dogs and cats, circulating volume may be reduced perioperatively due to:
Pre-operative fasting
Administration of medetomidine / dexmedetomidine
Stress related to hospitalisation
Insensible losses during general anaesthesia
All of the above
What is an appropriate intra-operative fluid plan for a diabetic cat that is mildly hypoglycaemic due to pre-anaesthetic fasting?
Hartmann’s (lactated ringers) solution with 2.5% glucose added at 5 mL/kg/hour
Plasmalyte 56 + 5% glucose at 5 mL/kg/hour
Glucose 5% solution at 5 mL/kg/hour
0.45% sodium chloride + 2.5% dextrose at 2.5 mL/kg/hour
0.9% saline at 3 mL/kg/hour
A DISADVANTAGE for using hypertonic saline solution when rapid volume replacement is required during general anaesthesia is:
It is time-consuming to start the infusion
It is expensive
It may cause electrolyte derangements and cellular dehydration
It causes coagulopathies
Risk of anaphylactic reaction
What is a “safe” fluid rate to start at for all normally hydrated cats and dogs intra-operatively?
3 mL/kg/hour
5 mL/kg/hour
1.5 x maintenance rate
3 mL/kg over 3 minutes
Anaesthetised animals require fluid rates that are higher than “maintenance” rates because:
(A) Anaesthetic drugs render animals less able to support their cardiac output in the face of reduced blood volume
(B) Certain sedative drugs cause diuresis
(C) They are often sub-clinically dehydrated prior to anaesthesia
(D) Both A. and C.
(E) All of the above
Regarding anaesthesia-related hypotension in dogs and cats:
All hypotensive animals will be fluid responsive
A 10 mL/kg bolus of crystalloid fluids should be administered as treatment immediately
Rapid administration of intravenous fluids is NOT an appropriate step in management of anaesthesia-related hypotension
A small yet rapid fluid “challenge” should be administered to ensure the animal is fluid responsive, prior to larger volume bolus administration
Cats should never receive a fluid challenge
An astute clinician can identify animals that may be fluid responsive by:
Visual inspection of a pulse plethysmography trace during mechanical ventilation
Visual inspection of an arterial waveform trace during spontaneous ventilation
Measurement of arterial blood pressure using a non-invasive oscillometric device
Visual inspection of a capnography waveform during mechanical ventilation
Peripheral pulse palpation