A comparison of oxygen saturation in white-tailed deer estimated by pulse oximetry and from arterial blood gases

Physiologic monitoring is important when chemically immobilizing wildlife. Blood oxygenation is usually monitored by pulse oximetry in the field; however, there is some question whether this technique accurately reflects oxygen saturation in wild white-tailed deer (Odocoileus virginianus). We evaluated different doses of medetomidine (125, 150, 175, or 200 μg/kg) mixed with ketamine (1.5 mg/kg), and tiletamine-zolazepam (1.0 mg/kg) in 22 female white-tailed deer at the University of Georgia Whitehall Deer Research Facility in Athens, Georgia on 14-15 and 21 May 2009. Deer were hand-injected intramuscularly while physically restrained in a squeeze chute, and then they were released into a pen for monitoring. Hemoglobin saturation estimated using pulse oximetry (SpO(2)) was compared with hemoglobin saturation value from arterial blood gases (SaO(2)) at 0, 10, and 20 min postimmobilization with deer in a sternal position. We made 56 simultaneous comparisons of oxygen saturation using SpO(2) (range, 54-95%) and SaO(2) (range, 60-95%). We used a Bland-Altman analysis for determining agreement between the two methods. Hemoglobin saturation estimated using SpO(2) was generally greater than SaO(2) when the mean of the two measurements was >80%. At mean values <80% oxygen saturation, there is not sufficient agreement between the techniques. Multiple readings over time may help recognition of outliers.     

Central blood oxygen saturation vs crying in preterm newborns

Infant cry characteristics reflect the development and possibly the integrity of the central nervous system. This study evaluates the distress occurring during cry in preterm newborn infants, as related to decrease of central blood oxygenation. A recording system was developed, that allows synchronised, non-invasive monitoring of blood oxygenation and audio recordings of newborn infant's cry. Cry episodes were identified by an automatic system allowing further analysis of the changes induced by the cry episodes on the oxygen saturation level in the central nervous system. Specifically, decrease in the oxygenation level appears during a cry episode, followed by recovery of the oxygenation after the cry episode is over. In the present work we compare a group of preterm infants with a control group of full term newborns in order to detect possible differences between the two sets of patients.Results indicate that a similar decrease in oxygenation level occurs in both groups of patients, but the recovery time after the crying episode is more stable and rapid in full term newborns than in preterm ones. This could prove useful for clinicians and nurses in the prevention of developmental diseases for this class of patients.