Effect of 24-hour sedation during mechanical ventilation on hematological, biochemical, and coagulation parameters in...

The effects of prolonged sedation on hematological, biochemical, and coagulation variables have not been previously investigated in veterinary medicine. Twelve healthy adult mixed-breed female dogs were included. Blood samples (6 mL) were collected at baseline (M0) for complete blood count (CBC), biochemical testing, prothrombin time (PT), activated partial thromboplastin time (PTT) and fibrinogen. After M0, dogs were allocated into two groups: midazolam-fentanyl-propofol group (MFG; n = 6), which received a continuous infusion of midazolam (0.5 mg/kg/h), fentanyl (10 µg/kg/h), and propofol (18 mg/kg/h); and ketamine-morphine-propofol group (KMG; n = 6), which received a continuous infusion of ketamine (0.6 mg/kg/h), morphine (0.26 mg/kg/h), and propofol (18 mg/kg/h). The infusion was maintained for 24 hours under mechanical ventilation. Laboratory parameters were reassessed from 12 to 24 hours after the beginning of infusion (M12 and M24), and at 12, 24, and 48 hours after the infusion (T12, T24, and T48). Both protocols significantly reduced erythrocyte count, packed cell volume, and haemoglobin concentration. In KMG, TTP decreased significantly at M12, M24, and T24; TSP at M24; and lymphocytes at M12 and M24. No significant changes were observed in ALP, ALT, albumin, globulins, creatinine, urea, glucose and blood coagulation. Triglyceride and cholesterol concentrations increased significantly from M6 to T48, but without biochemical evidence of hepatic, renal, or coagulation impairment. Overall, both protocols induced transient hematological and biochemical changes without clinically meaningful alterations in hepatic or renal function, supporting their use in healthy dogs mechanically ventilated for 24 hours.