Maintenance of Oxygen Transport in Severe Anemia

The ability of HBO to increase the arterial O₂ content in plasma to clinically useful levels may allow support of tissue O₂ delivery even in the absence of Hb. This fact has led to the application of HBO for temporary support of severely anemic patients pending the availability of definitive therapy in the form of crossmatched blood. Hart and coauthors^[47] reported the use of this technique in 26 patients. The mean hematocrit of all patients was 12.9%. The mean heart rate decreased from 124 to 98 beats/min after 30 minutes of breathing 100% O₂ at 2 ATA. Although the need for HBO to support tissue oxygenation in severe anemia is extremely rare, the temporary use of HBO to

Figure 70-5 Multiplace hyperbaric chamber large enough for one or more patients and tenders. The chamber atmosphere is compressed air. The patient receives 100% O₂ by mask, head tent, or endotracheal tube. Monitors are usually kept outside the chamber because of electrical safety considerations. Monitoring is possible through a porthole. A personnel lock and a transfer lock allow physicians, nurses, or other personnel, in addition to medications, food, and blood samples, to be moved into and out of the chamber without repeated compression and decompression of the patient.