Two methods to adapt the human haemoglobin–oxygen dissociation algorithm to the blood of white rhinoceros (Ceratotherium simum) and to determine the accuracy of pulse oximetry



      To adapt the algorithm for the calculation of oxygen saturation to the blood characteristics of the white rhinoceros by two different methods and to determine the accuracy of conventional pulse oximetry measurements.

      Study design

      Adaptation of two mathematical models of the oxygen dissociation curve (ODC).


      Twenty-five captive white rhinoceros (Ceratotherium simum), including 12 males and 13 females, aged 6–32 years.


      During 33 anaesthetic events, 94 arterial blood gas samples with 72 simultaneous pulse oximetry measurements were analysed. The calculation of oxygen saturation was adapted to the characteristics of rhinoceros blood using two different methods. Firstly, a mathematical model developed in 1984 and, secondly, an oxygen status algorithm (OSA) produced by the same developer in 2005 were tested for their applicability for clinical use.


      When arterial partial pressure of oxygen is >7.98 kPa (60 mmHg), oxygen saturation exceeds 95%. At partial pressures of 6.12–6.52 kPa (46–49 mmHg) Method 1 determined oxygen saturations of 92.5–95.3% and Method 2 oxygen saturations of 90.2–91.6%. Both methods resulted in similar ODCs and accounted for the low p50 value of rhinoceros blood. Method 1 provided better adaptation in respect to the physiological parameters of the rhinoceros, especially with regard to the Bohr effect, than Method 2. Pulse oximetry was an unreliable method of monitoring arterial oxygen saturation during general anaesthesia in this species.


      Adapting the oxygen saturation algorithm to consider the left shift of the ODC provides a useful tool for monitoring oxygen status, especially as pulse oximetry is insufficiently accurate. Experimental determination of the complete Hill curve is required to further validate and optimize the algorithm for use in the white rhinoceros.

      Clinical relevance

      The method will facilitate the accurate interpretation of oxygen saturation calculated by blood gas analysis in white rhinoceros.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Veterinary Anaesthesia and Analgesia
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Ball RL
        • Larsen R
        • Wagman J
        Investigating the hemoglobin of white rhinoceros (Cerathotherium simum simum) and possible implications for anaesthesia.
        in: Proceedings of the 2011 International Elephant and Rhino Conservation and Research Symposium. 2011: 1497-1521 (Rotterdam, the Netherlands)
        • Baumann R
        • Mazur G
        • Braunitzer G
        Oxygen properties of hemoglobin from the white rhinoceros (β2‐GLU) and the tapir.
        Respir Physiol. 1984; 56: 1-9
        • Burns PM
        • Driessen B
        • Boston R
        • et al.
        Accuracy of a third (Dolphin Voyager) versus first generation pulse oximeter (Nellcor N‐180) in predicting arterial oxygen saturation and pulse rate in the anesthetized dog.
        Vet Anaesth Analg. 2006; 33: 281-295
        • Citino SB
        • Bush M
        Reference cardiopulmonary physiologic parameters for standing, unrestrained white rhinoceroses (Ceratotherium simum).
        J Zoo Wildl Med. 2007; 38: 375-379
        • Matthews NS
        • Hartke S
        • Allen JC
        An evaluation of pulse oximeters in dogs, cats and horses.
        Vet Anaesth Analg. 2003; 30: 3-14
        • Mazur G
        • Braunitzer G
        • Wright PG
        Die Primärstruktur des Hämoglobins vom Breitmaulnashorn (Ceratotherium simum, Perissodactyla): β2 Glu.
        Hoppe Seylers Z Physiol Chem. 1982; 363: 1077-1086
        • Siggaard‐Andersen O
        • Wimberley PD
        • Göthgen I
        • et al.
        A mathematical model of hemoglobin–oxygen dissociation curve of human blood and of the oxygen partial pressure as a function of temperature.
        Clin Chem. 1984; 30: 1646-1651
        • Siggaard‐Andersen O
        • Wimberley PD
        • Fogh‐Andersen N
        • et al.
        Measured and derived quantities with modern pH and blood gas equipment: calculation algorithms with 54 equations.
        Scand J Clin Lab Invest. 1988; 48: 7-15
        • Verhovsek M
        • Henderson MPA
        • Cox G
        • et al.
        Unexpectedly low pulse oximetry measurements associated with variant hemoglobins: a systematic review.
        Am J Hematol. 2010; 85: 882-885