Objective of this clinical study was to assess the anaesthetic quality (induction and recovery) and utility of short term alfaxalone anaesthesia in healthy and diseased cats. Cardiopulmonary effects and the influence on haematological and biochemical blood parameters were evaluated.
Material and methods: Twenty feline patients (ASA1-4) were anaesthetized with alfaxalone for various short surgical or diagnostic procedures. Heart rate, breathing rate, end-tidal CO2 partial pressure, arterial oxygen saturation, mean arterial blood pressure and the body temperature were measured and recorded every 10 minutes. Before, after and 6 hours after anaesthesia venous blood samples were taken and haematologic and blood chemistry parameters were determined. Recovery time and quality were assessed by a numerical rating scale.
Results: Anaesthetic induction was rapid and smooth in all cats. Spontaneous respiration was maintained in all cats. Cardiopulmonary parameters mostly remained within a clinically tolerable range. Noticeable was a high heart rate (mean >190 bpm) at the beginning of anaesthesia lasting up to 10 minutes. Statistically significant changes (p<0.05) occurred in some haematologic parameters (RBC, haemoglobin, haematocrit and MCV decreased), electrolytes and venous acid-base-status (bicarbonate, chloride and base excess increased, sodium and potassium decreased) and blood chemistry parameters (alanine aminotransferase, glutamate dehydrogenase and creatinine decreased). None of these changes appeared to have clinical relevance. Recovery was smooth in the majority of cats. Mild signs of hyperexcitability (muscle tremor, short term opisthotonus and hyperacusis) occurred in individual animals. The duration of recovery varied between 21 and 93 minutes.
Conclusion and clinical relevance: Alfaxalone by repeated intravenous injection is suitable for short-term diagnostic and surgical procedures in cats. Because of its minor cardiovascular effects and slight respiratory depression, it is also well tolerated by patients with increased anaesthetic risk (ASA 3 and 4).