Evaluation of noninvasive monitoring techniques in domestic ferrets (Mustela putorius furo).

OBJECTIVE

To evaluate instrument placement and accuracy of indirect physiologic monitoring techniques in anesthetized domestic ferrets.

ANIMALS

10 healthy adult female ferrets (Mustela putorius furo).

PROCEDURE

Direct arterial blood pressure measurement and arterial blood sample collection were performed in ferrets. A pulse oximeter probe was clipped to a forefoot or hind foot; an airway adaptor for capnography was attached to the endotracheal tube; and a sphygmomanometer cuff and Doppler flow probe were positioned on the tail. Isoflurane and nitrous oxide concentrations were varied to induce episodes of hypotension or hypoxia, respectively. Aforementioned noninvasive techniques were compared with direct methods of arterial blood gas analysis, hemoximetry, and arterial blood pressure measurement. Simultaneously obtained direct and indirect measurements were statistically evaluated for mean and SD of the differences, and SEM, and subjectively, for ease of use and relevance to the clinical situation.

RESULTS

Values obtained from pulse oximetry were closely related to oxygen saturation measured by blood gas analysis (O2sat). The mean (+/- SD) difference for all results was -0.49 (+/- -4.09)%. The most precise measurements were obtained when O2sat was between 90 and 100%. Capnography measurements varied between ranges. The most accurate measurements were obtained when PaCO2 was < 25 mm of Hg, when the mean difference was 1.6 (+/- -3.01) mm of Hg. Indirect blood pressure measurement consistently underestimated the direct blood pressure value.

CONCLUSIONS AND CLINICAL RELEVANCE

Pulse oximetry is a convenient and accurate method for monitoring oxygen saturation in domestic ferrets. Capnography is useful for monitoring respiratory rate and pattern, but may present difficulties in interpretation of actual PaCO2. Indirect blood pressure monitoring is not accurate by use of current methods in ferrets.