ScvO₂ preceding intradialytic hypotension

This patient had a history of cardiomyopathy and symptoms on hemodialysis ranging from hypotension to "a funny feeling" at various times during treatment. The patient had previously been identified as having a low ScvO₂ and used oxygen with each hemodialysis treatment, most often with a mask instead of a nasal cannula due to nostril irritation. This patient's fluid gains were typically 1 to 2 kg between dialysis sessions. On the example exhibit the patient had a stable ScvO₂ ranging from 55 to 58% with 2 liters of oxygen per minute, but, in the beginning of the third hour, there was a sharp decrease in the ScvO₂ along with symptoms of hypotension and lightheadedness. A 100 mL bolus of normal saline (NS) improved the symptoms and the ScvO₂ for the remaining hour and a half. This patient had a history of having unexplained symptoms, often in the middle of the treatment, and the estimated dry weight was raised several times. Symptoms were lessened when the staff reacted to the decreasing ScvO₂ by reducing the ultrafiltration.