Apheresis in three dogs weighing <14 kg.

HISTORY

CaridianBCT apheresis machines require a ~285 mL priming volume (extracorporeal blood) that is withdrawn from the patient in ~10 minutes. Therefore, apheresis in dogs has generally been limited to dogs > ~20 kg to assure <20% of the blood volume is removed in the priming phase. ANIMALS/PHYSICAL EXAMINATION: Three dogs weighing <14 kg (13.6, 10.5, and 9.9 kg) with lymphoma that underwent apheresis.

MANAGEMENT

The dogs were premedicated for placement of apheresis catheters with hydromorphone (0.1 mg kg(-1) ) IM. Anesthesia was induced with propofol, to effect, intravenously and general anesthesia was maintained with isoflurane in oxygen. Following catheter placement, dogs were allowed to recover from isoflurane but were kept sedated with either a dexmedetomidine constant rate infusion (CRI) or a propofol CRI. Real time autologous blood priming was not performed in any of the dogs. Instead, priming solutions were composed of a combination of hetastarch, lactated Ringer's solution, and/or autologous blood that was harvested 4 days before the procedure. During apheresis, dogs received anticoagulant citrate-dextrose, solution-A (ACD-A) to prevent clotting and 10% calcium gluconate as needed to maintain normal ionized calcium concentrations. Dogs were monitored for cardiovascular and cardiopulmonary stability, anemia and lactic acidosis.

FOLLOW-UP: All of the dogs had cardiovascular and cardiopulmonary values within clinically acceptable ranges. Immediately following apheresis all of the dogs were mildly to moderately anemic (PCV; 17-35%) although none of the dogs required a transfusion or had an increased lactate concentration.

CONCLUSIONS

Dogs as small as 9.9 kg can successfully undergo apheresis with a variety of priming solutions. Dexmedetomidine or propofol given as a CRI provides sufficient sedation for this procedure.