Reliability of the enterprise point-of-care (EPOC) blood analyzer's calculated arterial oxygen-hemoglobin saturation in immobilized white rhinoceroses (Ceratotherium simum)

CONCLUSIONS: The EPOC cSaO2 is unreliable and should not be used to monitor blood oxygenation in immobilized white rhinoceroses.Please read abstract in the article.Agriculture Sector Education Training Authority; Centre for Veterinary Wildlife Research; Department of Paraclinical Sciences, University of Pretoria; Department of Veterinary Tropical Diseases, University of Pretoria; Dnata Wild-over-Wildlife; South African Government Health and Welfare Sector Education and Training Authority; Wiederhold Foundation.http://www.wileyonlinelibrary.com/journal/vcpAnatomy and PhysiologyCentre for Veterinary Wildlife StudiesParaclinical SciencesProduction Animal Studie

Effectiveness of pulse oximetry to detect hypoxaemia in immobilized impala (Aepyceros melampus)

Pulse oximetry is a cost-effective and a simple way to continuously monitor oxygenation of haemoglobin (SpO2) in humans and animals. Although pulse oximetry has been used extensively in wildlife, its efficacy and accuracy has not been validated. We aimed to establish, in immobilized impala, whether pulse oximetry is a reliable method to measure oxygenation of haemoglobin and aimed to determine which attachment site gives the most accurate measures. Sixteen healthy female impala were immobilized with etorphine or thiafentanil alone, or with a serotonin-agonist drug. Arterial blood samples were collected from the auricular artery at 5 minutes intervals during immobilization. At 40 minutes of immobilization, intranasal oxygen insufflation was provided to the impala at 5 L minute-1 flow rate to increase arterial oxygenation. A blood gas analyser was used to measure PaO2 (partial pressure of arterial oxygen) and calculate cSaO2 (calculated arterial haemoglobin oxygen saturation) and a co-oximeter was used to measure SaO2 (gold standard measure of arterial haemoglobin oxygen saturation) from arterial blood. Pulse oximeter probes were attached at four sites; namely under the tail, ear, rectum, and cheek. Pulse oximeter readings (SpO2 and pulse quality) were recorded at each site and compared with SaO2 and cSaO2 using Bland-Altman and accuracy root mean squares (Arms) methods to determine the efficacy. The pulse quality measured was generally good at each attachment site. Pulse oximetry measured under the tail was accurate and precise but only when SaO2 values were above 90% (bias = 3.03, precision = 3.15, Arms = 4.32). For the ear probe placement, overall bias and precision were high indicating that pulse oximetry was inaccurate (bias = -3.9) and imprecise (precision = 14.2). The cheek and rectal probe placement failed to give accurate or precise readings (cheek: bias = 11.63, precision = 10.86, Arms = 15.82 and rectum: bias = 4.9, precision = 12.02, Arms = 12.90). In order to get accurate and precise pulse oximetry readings in immobilized impala, probes must be placed under the tail and SaO2 must be above 90%. Since SaO2 values are usually low in immobilized impala, pulse oximeter readings should be interpreted with caution.Dissertation (MSc)--University of Pretoria, 2018.Paraclinical SciencesMScUnrestricte

Evaluation of the reliability of pulse oximetry, at different attachment sites, to detect hypoxaemia in immobilized impala (Aepyceros melampus)

Please read abstract in the article.The University of Pretoria, Faculty of Veterinary Science, Department of Paraclinical Science, South African Veterinary Association (Wildlife Group) and the National Research Foundation.https://www.journals.elsevier.com/veterinary-anaesthesia-and-analgesia2021-05-01hj2020Centre for Veterinary Wildlife StudiesCompanion Animal Clinical StudiesParaclinical Science

Reliability of pulse oximetry at four different attachment sites in immobilized white rhinoceros (Ceratotherium simum)

OBJECTIVES : To determine the reliability of peripheral oxygen haemoglobin saturation (SpO2), measured by a Nonin PalmSAT 2500A pulse oximeter with 2000T transflectance probes at four attachment sites (third eyelid, cheek, rectum and tail), by comparing these measurements to arterial oxygen haemoglobin saturation (SaO2), measured by an AVOXimeter 4000 co-oximeter reference method in immobilized white rhinoceros (Ceratotherium simum). STUDY : Randomized crossover study. ANIMALS : A convenience sample of eight wild-caught male white rhinoceros. METHODS : White rhinoceros were immobilized with etorphine (0.0026 ± 0.0002 mg kg–1, mean ± standard deviation) intramuscularly, after which the pinna was aseptically prepared for arterial blood sample collection, and four pulse oximeters with transflectance probes were fixed securely to their attachment sites (third eyelid, cheek, rectum and tail). At 30 minutes following recumbency resulting from etorphine administration, the animals were given either butorphanol (0.026 ± 0.0001 mg kg–1) or an equivalent volume of saline intravenously. At 60 minutes following recumbency, insufflated oxygen (15 L minute–1 flow rate) was provided intranasally. In total, the SpO2 paired measurements from the third eyelid (n = 80), cheek (n = 67), rectum (n = 59) and tail (n = 76) were compared with near-simultaneous SaO2 measurements using Bland-Altman to assess bias (accuracy), precision, and the area root mean squares (ARMS) method. RESULTS : Compared with SaO2, SpO2 measurements from the third eyelid were reliable (i.e., accurate and precise) above an SaO2 range of 70% (bias = 1, precision = 3, ARMS = 3). However, SpO2 measurements from the cheek, rectum and tail were unreliable (i.e., inaccurate or imprecise). CONCLUSIONS AND CLINICAL RELEVANCE : A Nonin PalmSAT pulse oximeter with a transflectance probe inserted into the space between the third eyelid and the sclera provided reliable SpO2 measurements when SaO2 was > 70%, in immobilized white rhinoceros.The National Research Foundation of South Africa, the South African Veterinary Association (Wildlife Group), the Wiederhold Foundation and the Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria.https://www.journals.elsevier.com/veterinary-anaesthesia-and-analgesia2023-10-31hj2022Anatomy and PhysiologyCentre for Veterinary Wildlife StudiesCompanion Animal Clinical StudiesParaclinical Science