February 11, 2013
Problems with High A1c for Type 2 Patients
Until this article in Medscape, I had not imagined all the potential problems elevated A1c's could cause for people with diabetes. Yes, we are all aware of the complications, (retinopathy, neuropathy, nephropathy, atherosclerosis, deafness, cognitive decline), and how they love people with elevated A1c's. These complications set up shop quickly in people that let their blood glucose levels stay consistently elevated and do their best to take over these people.
New problems keep emerging for people with unmanaged type 2 diabetes, so I should not have been surprised when I read this article. In reading this, I did agree because when I think of hyperbaric oxygen therapy being used for wound healing, this explains why it is necessary because the blood cannot carry sufficient oxygen to the cells around the wound to promote healing.
The oxygen saturation (SaO 2) and partial pressure of oxygen (PO 2) in this trial was measured with simultaneous monitoring of SpO 2 in 261 type 2 patients during ventilation or oxygen inhalation. Pulse oximetry is the measuring of oxygen saturation in the veins by placing a sensor on the finger or earlobe of an adult or even children. For infants, the sensor is placed across the foot.
The study showed the relationship of diabetes that was poorly managed (A1c greater that 7%) to diabetes that was managed (A1c less than 7%) and the amount of oxygen in the blood. Those that were highest in oxygen were clearly those with A1c's less than 7%. However, it was confirmed by using arterial blood gas analysis (the method used before pulse oximetry became the standard) that the amount of oxygen in the blood was less than the pulse oximetry recorded. This raises the concern about those with A1c's in excess of 7% having enough oxygen in the blood for proper cell oxygenation.
Therefore, the researchers are correct in the alerting of treating patients for hypoxemia (inadequate oxygenation of the blood) that using the pulse oximetry is misleading for type 2 patients with elevated A1c levels. They recommend using arterial blood gas analysis for patients with poor blood glucose control during the treatment of hypoxemia to receive best results.