Severe Anemia
Patients who develop exceptional anemia have lost significant oxygen carrying capacity in the blood. These patients become candidates for hyperbaric oxygen therapy (HBOT) when they are unable to receive blood products because of religious or medical reasons. The major oxygen carrier in human blood is hemoglobin, transporting 1.34 mL of oxygen per gram. Borema performed an experiment in the 1960s in which exsanguinated pigs (who had only plasma in their vasculature) were able to sustain life under hyperbaric conditions. The body generally uses 5-6 vol% (mL of O2 per 100 mL of blood); [101] under 3 ATA, 6 vol% of molecular oxygen can be dissolved into the plasma. [102] The CNS and cardiovascular systems are the two most oxygen-sensitive systems in the human body. Oxygen debt is one way of determining a patient’s need to start or continue HBOT. A cumulative oxygen debt is the time integral of the volume of oxygen consumption (VO2) measured during and after shock insult minus the baseline VO2 required during the same time interval. Patients who have a debt greater than 33 L/m2 do not survive, whereas patients with debts ≤9 usually recover. |
Treatment Protocol
HBOT is administered at 2-3 ATA for periods of up to four hours per treatment. As many as 3-4 sessions a day may be necessary, depending on a patient’s clinical picture. Treatments should continue until the patient can receive blood products, no longer demonstrates end stage organ failure, or no longer has a calculated oxygen debt. |