Page 345 - WSAVA2017
P. 345

WSVA7-0472
BIRDS, EXOTICS, RABBITS
AVIAN FLUID THERAPY - THE ESSENTIALS
T. Tully1
1Louisiana State University School of Veterinary Medicine, Veterinary Clinical Sciences, Baton Rouge- Louisiana, USA
AVIAN FLUID THERAPY – THE ESSENTIALS
Thomas N. Tully, Jr., DVM, MS, DABVP (Avian), ECZM (Avian)
Louisiana State University – School of Veterinary Medi- cine
Baton Rouge, Louisiana
Email: ttully1@lsu.edu
GOALS OF FLUID THERAPY
1. Administer the least amount of fluids needed by the patient
2. Restore perfusion and hydration without volume over- load
3. Have a treatment goal
4. Assess clinical response toward treatment goal 5. Early intervention
FLUID THERAPY
If it is determined the patient can withstand the stress
of handling and treatment then fluid therapy may be initiated. Normosol or Lactated Ringers Solution can be administered through the following routes: subcutane- ous, intravenous, intraosseous, orally and through the cloaca. Anatomic sites commonly used for IO catheter placement include the distal ulna (larger birds), proximal ulna, proximal tibiotarsal bone and lateral femur (young and small birds). Placement of the IO catheter begins with proper site preparation, similar to epithelial prepara- tion for an IV catheter. A 22-gauge, 11⁄2” spinal needle is the catheter of choice in most psittacine cases although any size needle may be used, provided that a stylet is inserted into the needle prior to placement of the IO catheter into the medullary cavity of the bone.1 When the IO catheter is placed in the distal ulna, the distal wing tip is flexed and the needle is inserted at a 45 to 60° angle, and this angle is reduced once the catheter enters the cortex.2 The needle should be advanced to the hub, stylet removed and the catheter flushed with heperized saline. The catheter is capped with a PRN and managed as an IV catheter. Intraosseous catheters require more maintenance than an IV catheter and should be flushed 6 to 8 times a day to maintain patency. Subcutaneous fluid
therapy is not an effective method of rapid restoration of circulatory fluid volume.3 Adding hyaluronidase (Wydase, Wyeth-Ayerst Pharmaceuticals, Philadelphia, PA) to lac- tated Ringer’s solution (LRS) for SC fluid administration has been recommended as a method to increase the absorption rate of the fluid into the circulatory system.1
When determining the dehydration deficit of a psittacine patient, the veterinarian must estimate the percentage
of deficit prior to calculating replacement fluid volumes. Parameters applied to measure dehydration status in psittacine species include skinfold elasticity, corneal moisture, appearance of the globe and packed cell volume. Dehydrated psittacine chicks have wrinkled and reddened skin, with a sunken face and prominent eyes.4 It is generally believed that in most cases of severe trau- ma or disease a 5% to 10% dehydrated status should
be estimated for the avian patient. The estimated deficit should be replaced over a 48 – 72 hour period.1 The rec- ommended daily fluid maintenance formula for psittacine species is 100 ml/kg/day, and baby birds consume 2 to 3 times the maintenance fluid levels as adult patients.1 but may range between 50 – 150 ml/kg/day depending on species of bird being treated. Recent recommenda- tions to compensate for tissue fluid loss are a crystalloid (e.g. LRS) 10 ml/kg + colloid (eg, hetastarch) at 5 ml/kg increments. The crystalloid/colloid combination given at 1 to 2 bolus infusions will generally raise the blood pres- sure to greater than 90 mm Hg systolic. Fluids should
be warmed before administration and bolus fluids can be given with relative safety IO or IV over a 3 – 5 minute period. Once the fluid deficit is replaced and the bird is eating and drinking normally for 2 or 3 days, the mainte- nance hydration therapy can be discontinued.
Fluids therapy may be replaced through subcutaneous, intravenous or intraosseous administration. Subcutane- ous fluid replacement can be achieved using a 26 or 25 gauge needle attached to a syringe filled with a warmed crystalloid or colloidal agent. The sites usually preferred for subcutaneous administration are the featherless ingui- nal and/or axillary regions of most avian species. Intra- venous catheters are placed in the jugular vein of larger birds and median metatarsal of smaller companion avian species. The distal ulna and proximal tibiotarsal bone
are the recommended sites for IO catheter placement. Although IO catheter placement is easier in smaller birds, these catheters require more maintenance to prevent plugging. Intraosseous catheters have a similar delivery to IV catheters and are much easier to place, especially in smaller species.
Lactated Ringer’s solution (LRS), 2.5% dextrose in 4.5% saline, and 0.9% saline comprise the commonly used isotonic crystalloid solutions administered to avian species. The necessity for continuous fluid
An Urban Experience
  345
                   






































































   343   344   345   346   347