A clinical practice guideline for the use of hyperbaric oxygen therapy in the treatment of diabetic foot ulcers

BACKGROUND: The role of hyperbaric oxygen (HBO2) for the treatment of diabetic foot ulcers (DFUs) has been examined in the medical literature for decades. There are more systematic reviews of the HBO2/DFU literature than there have been randomized controlled trials (RCTs), but none of these reviews has resulted in a clinical practice guideline (CPG) that clinicians, patients and policy-makers can use to guide decision-making in everyday practice. METHODS: The Undersea and Hyperbaric Medical Society (UHMS), following the methodology of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group, undertook this systematic review of the HBO2 literature in order to rate the quality of evidence and generate practice recommendations for the treatment of DFUs. We selected four clinical questions for review regarding the role of HBO2 in the treatment of DFUs and analyzed the literature using patient populations based on Wagner wound classification and age of the wound (i.e., acute post-operative wound vs. non-healing wound of 30 or more days). Major amputation and incomplete healing were selected as critical outcomes of interest. RESULTS: This analysis showed that HBO2 is beneficial in preventing amputation and promoting complete healing in patients with Wagner Grade 3 or greater DFUs who have just undergone surgical debridement of the foot as well as in patients with Wagner Grade 3 or greater DFUs that have shown no significant improvement after 30 or more days of treatment. In patients with Wagner Grade 2 or lower DFUs, there was inadequate evidence to justify the use of HBO2 as an adjunctive treatment. CONCLUSIONS: Clinicians, patients, and policy-makers should engage in shared decision-making and consider HBO2 as an adjunctive treatment of DFUs that fit the criteria outlined in this guideline. The current body of evidence provides a moderate level of evidence supporting the use of HBO2 for DFUs. Future research should be directed at improving methods for patient selection, testing various treatment protocols and improving our confidence in the existing estimates.(AU)

Gender differences in human skeletal muscle and subcutaneous tissue gases under ambient and hyperbaric oxygen conditions.

OBJECTIVES: The purpose of this study is to ascertain if gender differences exist in human skeletal muscle (MM) and subcutaneous (SC) tissue gases using monoplace and multiplace hyperbaric oxygen (HBO2) treatment protocols. METHODS: Gas tensions in resting MM and SQ tissues were recorded at 4-minute intervals using two protocols: The 150 minute monoplace HBO2 chamber protocol utilized continuous oxygen (O2) breathing at 202.6 kPa, that is 2 atmospheres absolute (2 ATA). The multiplace HBO2 chamber protocol had four 5-minute air breaks between five 20 minute O2 breathing periods at 2 ATA and took 180 minutes to complete. Tissue gas samples were obtained by the vacuum technique through a low permeable Teflon membrane and analyzed using a mass spectrometer. RESULTS: Over 40,000 individual step analyses showed gas tensions changed (repeated measures of variance, p = 0.00001) with time as the gas pressures and mixtures breathed were altered. Statistically significant differences between males and females in loading and unloading of SC nitrogen (N2) (P = 0.0001), SC O2 (P = 0.001) and MM O2 (P = 0.003) were observed in the multiplace protocol. Females release SC N2 more slowly; while increasing their MM and SC O2 tensions higher than males. Muscle and SC CO2 levels decrease in both males and females when exposed to HBO2 and increase when breathing air. CONCLUSIONS: Three main gender differences are observed in tissue gas loading and unloading under hyperbaric oxygen exposures: Females release SC N2 more slowly and saturate MM O2 and SC O2 to greater extents. Finally, female MM and SC O2 rose to higher levels in the multiplace protocol than in the monoplace protocol, which was not observed in the male subjects. This information may help explain why males and females respond differently to diving decompression stresses and the clinical application of HBO2.

Diving medicine: contemporary topics and their controversies.

SCUBA diving is a popular recreational sport. Although serious injuries occur infrequently, when they do knowledge of diving medicine and/or where to obtain appropriate consultation is essential. The emergency physician is likely to be the first physician contact the injured diver has. We discuss 8 subjects in diving medicine which are contemporary, yet may have controversies associated with them. From this information the physician dealing primarily with the injured diver will have a basis for understanding and managing, as well as where to find additional help, for his/her patients' diving injuries.

Cigarette smoking and transcutaneous oxygen tensions: a case report.

We report the effects of acute smoking cessation on transcutaneous oxygen (PtcO2) measurements in room air and with hyperbaric oxygen (HBO2) of an extremity at risk for amputation. The reports on cigarette smoking and PtcO2 do not discuss acute smoking cessation. PtcO2 measured 46 h after smoking cessation increased 10% while breathing room air and 34% with HBO2, as compared to measurements made before smoking cessation.

Effect of increased atmospheric pressure on radial keratotomy.

PURPOSE: To evaluate the effect of increased atmospheric pressure on visual acuity in patients who have had radial keratotomy (RK). SETTING: Long Beach Memorial Medical Center, Long Beach, California, USA. METHODS: This controlled clinical study comprised 4 eyes that had RK and 4 control eyes that were age and sex matched. All patients had prehyperbaric chamber examinations consisting of manifest and cycloplegic refractions, intraocular pressure (IOP), keratometry, and corneal pachymetry. They were then placed into the hyperbaric chamber for 1 hour. Immediately after the patients were removed from the chamber, the examinations were performed again. RESULTS: No statistically significant changes in visual acuity, refractive error, IOP, keratometry, or pachymetry occurred in the 2 groups. CONCLUSION: The results of this study indicate that, unlike at high altitudes, RK is stable at increased atmospheric pressure. This suggests that RK patients can engage in recreational scuba diving without encountering deleterious visual changes.

Preventive foot care. A user-friendly system for patients and physicians.

Our user-friendly foot skin and toenail grading system is simple to understand for both patients and physicians. Current medical practice dictates that primary care physicians deliver the most comprehensive care possible for their patients. This includes preventive care and documentation of outcomes. Our approach simplifies evaluation and management of the majority of foot skin and toenail conditions in compromised hosts. Reimbursement for the extra care is justified, and authorized billing codes exist. Our system helps to prevent the physical, emotional, and financial costs associated with severe foot wounds and nail disorders. We remind our patients that proper foot care is as important in preventing foot complications as drug therapy is in preventing complications in other organs. Our approach to foot skin and toenail care is largely prophylactic and can be easily instituted in a primary care practice.

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.

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Otitis externa associated with aquatic activities (swimmer's ear).

Infections of the ear canal may vary in terms of severity. Their frequency and morbidity qualify them as significant aquatic problems. The aquatic environment adds the conditional variable of moisture to the ear canal. Usually bacteria are introduced with the moisture and in the warm environment of the canal multiply, generate debris, invade the canal lining, and generate the symptoms of otitis externa. Fortunately, the incidence of this condition can be minimized by eliminating moisture in the canal. In situations where excessive moisture is likely to be introduced such as in swimmers, scuba divers, and deep sea divers the prophylactic measures of desiccation and acidification of the canal should be used. They are very effective. In the saturation diver, ear canal infections are not likely to resolve without interruption of diving activities. Individuals who have recurring ear canal infections require evaluation by an ear specialist to identify possible remedial problems that can trigger infection. Correction of anatomical problems or underlying dermatoses can prevent recurrences of OE.

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)

Delayed use of hyperbaric oxygen for treatment of a model anterior compartment syndrome.

This study examines the effect of delayed exposure to hyperbaric oxygen on muscle necrosis and edema development following compartment syndromes in the canine hindlimb. Compartment syndromes (100 mm Hg for 8 h) were generated in one anterolateral compartment of six anesthetized dogs. After a 2-h delay, three 1-h hyperbaric oxygen treatments (2 atm absolute pure oxygen) were given during the next 12 h. Two days later, technetium-99m stannous pyrophosphate (99mTc Sn-PYP) was injected intravenously; 3 h later, samples were obtained from the pressurized and contralateral control muscles, weighed for edema development, counted for 99mTC Sn-PYP uptake, and evaluated histologically. Hyperbaric oxygen treatments, even when delayed 2 h, reduced muscle necrosis and intramuscular edema to negligible levels (p less than 0.05) compared with untreated animals. In addition, muscle morphology remained essentially normal in all hyperbaric oxygen-treated animals. We conclude that even if hyperbaric oxygen treatments are delayed 2 h, edema and muscle necrosis are reduced significantly in a model compartment syndrome.