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Biomedical subjects

G B Hart

Publications and source records attributed to G B Hart.

12 recordsLinked to original sources

Hyperbaric oxygen therapy for acute smoke inhalation injuries.

Hyperbaric oxygen therapy is an important adjunct in the management of respiratory injuries secondary to smoke inhalation, especially when injury is complicated by inhalation of a toxic chemical such as carbon monoxide or cyanide. For carbon monoxide poisoning, such therapy has become a standard of practice. As more information becomes available concerning the ability of hyperbaric oxygen to reduce reperfusion injuries, we anticipate that this therapy will become a standard of practice for managing smoke inhalation injuries and cyanide poisoning as well.

Antidotes

Intermittent hyperbaric oxygen therapy for reduction of mortality in experimental polymicrobial sepsis.

Hyperbaric oxygen therapy has a marked beneficial effect in experimental intraabdominal sepsis. Two rat models involving implantation of either rat fecal material or a mixture of pure cultures of Escherichia coli, Streptococcus faecalis, and Bacteroides fragilis were used in this study. A death rate of 100% was obtained in control animals implanted with fecal material; with intermittent hyperbaric oxygen treatment, a death rate of only 8% was observed (P less than .005). With a mixture of pure cultures of clinical pathogens, the death rate in control animals was 79%, and intermittent hyperbaric oxygen treatment reduced the rate to 23% (P less than .005). Data from cultures of blood indicated that the efficacy of hyperbaric oxygen was not related to antibacterial activity.

Animals

Hyperbaric oxygen reduces edema and necrosis of skeletal muscle in compartment syndromes associated with hemorrhagic hypotension.

This study examined the effect of exposures to hyperbaric oxygen on the development of the edema and necrosis of muscle that are associated with compartment syndromes that are complicated by hemorrhagic hypotension. A compartment syndrome (twenty millimeters of mercury for six hours) was induced by infusion of autologous plasma in the anterolateral compartment of the left hind limb of seven anesthetized dogs while the mean arterial blood pressure was maintained at sixty-five millimeters of mercury after 30 per cent loss of blood volume. These dogs were treated with hyperbaric oxygen (two atmospheres of pure oxygen) and were compared with six dogs that had an identical compartment syndrome and hypotensive condition but were not exposed to hyperbaric oxygen. Forty-eight hours later, edema was quantified by measuring the weights of the muscles (the pressurized muscle compared with the contralateral muscle), and necrosis of muscle was evaluated by measuring the uptake of technetium-99m stannous pyrophosphate. The ratio for edema was significantly (p = 0.01) greater in dogs that had not been exposed to hyperbaric oxygen (1.15 +/- 0.01) than in the dogs that had been treated with hyperbaric oxygen (1.01 +/- 0.03), and the ratio for necrosis of muscle was also significantly (p = 0.04) greater in dogs that had not had hyperbaric oxygen (1.96 +/- 0.41) than in those that had been treated with hyperbaric oxygen (1.05 +/- 0.11). Comparisons were also made with the muscles of four normal control dogs and separately with the muscles of six normotensive dogs that had an identical compartment syndrome and normal blood pressure and were not treated with hyperbaric oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Tissue gas and blood analyses of human subjects breathing 80% argon and 20% oxygen.

Eight human volunteers, individually studied in a hyperbaric chamber, breathed: 1) air at 1 ATA; 2) 80% argon and 20% oxygen and 1 ATA for 30 min; 3) air at 1 ATA for 30 min; 4) 100% 02 at 1 ATA for 30 min; 5) air at 1 ATA for 30 min; 6) 100% O2 at 2 ATA for 60 min; and 7) 80% argon and 20% oxygen at 1 ATA for 30 min. Oxygen, carbon dioxide, nitrogen, and argon tensions were measured in muscle and subcutaneous tissue by mass spectroscopic analyses. Venous blood obtained at regular intervals was analyzed for coagulation and fibrinolytic factors. Inert gas narcosis was not observed. After breathing argon for 30 min, muscle argon tensions were almost three times subcutaneous tensions. Argon wash-in mirrored nitrogen wash-out. Argon wash-in and wash-out had no effect on tissue Po2 or Pco2. Coagulation and fibrinolytic changes usually associated with vascular bubbles were absent.

Adult

Hyperbaric oxygen treatment of refractory osteomyelitis.

Of 70 patients with refractory osteomyelitis who received treatment with hyperbaric oxygen, all improved and 63% have remained free of disease. Treatment is supplemental to properly timed surgery and antibiotic therapy.

Adolescent

The treatment of radiation necrosis with hyperbaric oxygen (OHP).

Sixty-nine patients with radiation necrosis were received by the authors from January 1, 1969 through August 1, 1975. The patients were categorized according to site of injury. Full treatment protocol is discussed including local wound care, antibiotic coverage, surgical procedures, and the administration of hyperbaric oxygen. Results indicate that the combination of hyperbaric oxygen, properly timed surgery, and antibiotic therapy has resulted in improvement in all cases of radiation necrosis and full healing in most.

Aged

Screening test for decompression sickness.

The fibrin-fibrinogen degradation products (FDP) tests were studied in 18 patients having a history of illness associated with diving. FDP tests were performed prior to hyperbaric oxygen therapy (OHP). Eight patients were serious neurologic signs had positive FDP tests and required repetitive therapy. Six patients had negative FDP tests with local musculoskeletal complaints and all were asymptomatic following the first OHP treatment. Three patients were found to be suffering from other diseases. These three patients had normal levels of FDP. One patient treated at another facility 3 months earlier and having paraplegia had a positive FDP test. Serious decompression sickness with neurologic complaints appear to have some degree of disseminated intravascular coagulation (DIC) as reflected by the FDP tests. The FDP test appears to be a useful screening test that may be able to delineate therapy.

Adolescent

Osteoradionecrosis of the mandible. Treatment with hyperbaric oxygen.

Hyperbaric oxygen used in the treatment of 14 patients with intractable osteonecrosis of the mandible produced a favorable response in relief of pain, elimination of extraoral draining sinus tracts, the return of osseous union in areas of the abnormal fracture, and the rapid dissolution of sequestrum without suppuration, so that further loss of hard and soft tissue was minimized. This treatment is a more conservative approach in the management of osteoradionecrosis.

Adult

Hyperbaric oxygen treatment of mandibular osteomyelitis in osteopetrosis.

A patient was successfully treated with hyperbaric oxygen for chronic osteomyelitis of the mandible associated with osteopetrosis. This mode of therapy appears to have a definite place in the management of such patients. There was no clinical, radiographic, or laboratory evidence that the osteopetrosis was made worse by the hyperbaric oxygen.

Female