Plasma Colloid Osmotic Pressure in Chronic Debilitated Loggerhead Sea Turtles (Caretta caretta)
Abstract
Colloid osmotic pressure (COP) is an important component of the forces that manage capillary filtration and is determined by circulating plasma proteins.1-3 Since chronic debilitated sea turtles present with severe hypoproteinemia, opportunistic infections, and occasionally sepsis, understanding COP in this condition can contribute to understanding the pathophysiology of this condition and provide valuable information for treatment strategies in these critically ill patients.4 The objectives of this study were to 1) determine differences in plasma COP and blood analyte data [packed cell volume (PCV), sodium, chloride, plasma protein fractions] in chronic debilitated loggerhead turtles at admission compared to data from healthy turtles at time of release, and 2) to investigate correlations of COP with these selected blood analytes. COP, PCV, and most plasma protein fractions (excluding gamma-globulins) were significantly lower in chronic debilitated loggerhead turtles upon admission as compared to healthy animals. Sodium, chloride, and gamma globulins did not significantly differ between time points. A significant increase was observed in PCV and all plasma protein fractions as COP increased. Of all protein fractions tested, albumin contributed the most toward colloid osmotic pressure (r2= 0.88, p<0.001). The results of this study confirm that COP is significantly lower in chronic debilitated as compared to healthy sea turtles, which provides insight into the severity and chronicity of this clinical condition. This finding has important implications for treatment of debilitated turtles as recent research findings in emergency critical care medicine have resulted in a shift away from colloids towards a combination of crystalloid and nutritional therapy to support the recovery of endothelium health and to restore hemodynamic stability.5,6
Acknowledgements
This study was performed at the University of Florida College of Veterinary Medicine and was supported by internal funds from the Aquatic Animal Health Program. Special thanks to the rehabilitation staff of Loggerhead Marinelife Center for the use of their patient medical records and treatment and care of stranded sea turtles.
* Presenting author
+ Student presenter
Literature Cited
1. Stewart RH. 2000. Editorial: the case for measuring plasma colloid osmotic pressure. Journal of Veterinary Internal Medicine. 14.5:473–474.
2. Stockham SL, et al. 2008. Colloidal osmotic pressure. In: Fundamentals of Veterinary Clinical Pathology. 2nd ed. Ames (IA): Blackwell; 405–411.
3. Guardia JA, et al. 1997. Oncotic pressure and edema formation in hypoalbuminemic HIV-infected patients with proteinuria. American Journal of Kidney Diseases. 30(6):822–828.
4. Manire CA, et al. 2017. Chronic debilitation. In: Sea Turtle Health and Rehabilitation. Plantation, FL: J. Ross Publishing; 707–724.
5. Bellomo MP. 2016. A rational approach to fluid therapy in sepsis. British Journal of Anaesthesia. 116:339–349.
6. Woodcock TE, Woodcock TM. 2012. Revised Starling equation and the glycocalyx model of transvascular fluid exchange: an improved paradigm for prescribing intravenous fluid therapy. British Journal of Anaesthesia. 108(3):384–394.