Assessment of clinical application of pulse oximetry probes in llamas and alpacas

The placement and accuracy of pulse oximeter probes can vary markedly among species. For our study, we aimed to assess the accuracy of pulse oximetry and to determine the most clinically useful sites for probe placement in llamas and alpacas. The objectives included an analysis of pulse oximetry probes for accurate assessment of llamas and alpacas and to determine the best placement of the probes to achieve accurate readings. For study 1, saturation of haemoglobin with oxygen was measured in 184 arterial blood gas samples (SaO(2)) using a co-oximeter and compared to saturation of haemoglobin with oxygen simultaneously measured using a pulse oximeter (SpO2). The bias and precision for the SpO(2)-SaO2 difference was calculated and plotted on a Bland-Altman plot. For study 2, SpO2 data was collected 624 times from a variety of sites [tongue (T), nasal septum (NS), lip (L), vulva (V), prepuce (P), ear (E), and scrotum (S)] and recorded based upon a percentage of successful readings. Results for study 1 revealed that SpO2 was consistently 0 to -6% points different than SaO2. The bias and precision of the SpO2-SaO2 difference was -2.6 +/- 1.7%. Results for study 2 uncovered that 540 recordings were successful readings and were obtained from the tongue and nasal septum with 97% accuracy, the lip 80%, vulva 62%, prepuce 59%, ear and scrotum < 50%. We concluded that pulse oximetry probes provide reliable estimates of arterial haemoglobin oxygen saturation in llamas and alpacas and is most accurately read when placed on the nasal septum or tongue.