Serial blood gas analysis during fluid resuscitation of hypovolemic dogs

It has been documented that hemodynamic disturbances occur in hypovolemic patients. Therefore, the early management of hypovolemia is essential to achieve optimal outcomes. Blood gas, which changes rapidly during hemodynamic instability, can be used as a diagnostic approach for monitoring emergency patients. The objective of the current study was to evaluate the results of resuscitation with hydroxyethyl starch (HES) or lactated Ringer's solution (LR) on venous and arterial blood gas. In addition, the difference between venous and arterial blood gas parameters is investigated to assess the possibility of using venous blood gas analysis as a successor for arterial blood gas analysis in the resuscitation of hypovolemic dogs. Venous and arterial pH, PO2, PCO2, HCO3-, and base excess were analyzed at the end of each study stage as follow: 1) Establishment of anesthesia, 2) Blood collection to an arterial mean pressure of 40-50 mm Hg, 3) Maintaining dogs in a hypovolemic state, 4) Resuscitation with LR (group A) or HES (group B) in four steps, and 5) One hour after the final resuscitation step. Hypovolemia decreased the studied parameters, except venous PCO2, which showed a significant increase (p < 0.05). Fluid resuscitation returned the studied parameters to the control values as venous PCO2 in group A and HCO3- in group B showed a significant change in comparison with the control values (p < 0.05). We found that venous pH, HCO3-, and PCO2 can be used as less invasive and safer alternatives to similar arterial parameters to monitor the fluid resuscitation of hypovolemic dogs.