[HYPERBARIC OXYGEN THERAPY (HBO) FOR RADIATION NECROSIS - PHYSICIAN AWARENESS IS REQUIRED].

INTRODUCTION: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.4 atmospheres absolute (ATA), 140 kPa, in the hyperbaric chamber. The therapeutic effect is obtained by delivery of oxygen to the tissues dissolved in the plasma and independent of the hemoglobin. At an ambient chamber pressure of 2 to 2.4 ATA, the amount of plasma-dissolved oxygen can reach more than 6 vol %, which is sufficient to supply the body's basic metabolic requirements, while arterial PO2 can reach more than 2,000 mmHg. Under these conditions, oxygen catches up with and overtakes physics and physiology, enabling numerous physiological processes to take place. This includes angiogenesis in areas of reduced oxygen tension due to poor vascularity, increased collagen production, and edema reduction, among others. Such mechanisms promote wound healing and the recovery of radiation-injured tissue. HBO therapy has firm support in evidence-based medicine. The indications for treatment are approved by the Israel Ministry of Health and recognized by medical insurance providers. Nevertheless, lack of knowledge and insight make it necessary to heighten physician awareness of HBO as a safe procedure, and as the principal modality of treatment for radiation injury to otherwise healthy tissue.

Prognostic factors predicting ischemic wound healing following hyperbaric oxygenation therapy.

Identifying patients who benefit from hyperoxygenation therapy is important, because treatment is time-consuming and involves high costs and complications (minor). Our objective was to develop a model for predicting therapy outcome based on population of patients with and without diabetes. A retrospective cohort study was carried out in a major hospital in Israel. All 385 patients treated between 1/1/1998 and 1/1/2007 for ischemic nonhealing lower extremities wounds were included. Data on medical history, demographic, transcutaneous oximetry, wounds, treatment, and outcome characteristics were collected. Eight factors were identified to optimally predict wound healing: (1) number of hyperbaric oxygenation treatments (odds ratio [OR] = 1.034, p < 0.001), (2) transcutaneous oximetry values at hyperbaric conditions (OR = 1.001, p = 0.019), (3) wound duration (OR = 0.988, p = 0.022), (4) absence of heart disease (OR = 3.304, p < 0.001), (5) being employed (OR = 3.16, p = 0.008), (6) low socioeconomic status (OR = 2.50, p = 0.004), (7a) good/partial granulation wound appearance (OR = 2.73, p = 0.022), (7b) wounds covered with fibrin (OR = 3.16, p = 0.015), and (8) absence of anemia (OR = 2.13, p = 0.016). The model's sensitivity is 78.7%, specificity is 62.9%, and accuracy is 71.8%. We suggest using our model as an adjunct to patients' clinical evaluation. Also, we recommend initiating hyperoxygenation therapy no later than 2 months after wound appearance.

Large leg ulcers due to autoimmune diseases.

BACKGROUND: Large leg ulcers (LLU) may complicate autoimmune diseases. They pose a therapeutic challenge and are often resistant to treatment. To report three cases of autoimmune diseases complicated with LLU. CASE REPORT: Case 1. A 55-year old woman presented with long-standing painful LLU due to mixed connective tissue disease (MCTD). Biopsy from the ulcer edge showed small vessel vasculitis. IV methylprednisolone (MethP) 1 G/day, prednisolone (PR) 1mg/kg, monthly IV cyclophosphamide (CYC), cyclosporine (CyA) 100mg/day, IVIG 125G, ciprofloxacin+IV Iloprost+enoxaparin+aspirin (AAVAA), hyperbaric oxygen therapy (HO), maggot debridement and autologous skin transplantation were performed and the LLU healed. Case 2. A 45-year old women with MCTD developed multiple LLU's with non-specific inflammation by biopsy. MethP, PR, hydroxychloroquine (HCQ), azathioprine (AZA), CYC, IVIG, AAVAA failed. Treatment for underlying the LLU tibial osteomyelitis and addition of CyA was followed by the LLU healing. Case 3. A 20-year-old man with history of polyarteritis nodosa (PAN) developed painful LLU's due to small vessel vasculitis (biopsy). MethP, PR 1 mg/kg, CYC, CyA 100 mg/d, AAVAA failed. MRSA sepsis and relapse of systemic PAN developed. IV vancomycin, followed by ciprofloxacin, monthly IVIG (150 g/for 5 days) and infliximab (5 mg/kg) were instituted and the LLU's healed. CONCLUSIONS: LLU are extremely resistant to therapy. Combined use of multiple medications and services are needed for healing of LLU due to autoimmune diseases.

Improvement of ischemic non-healing wounds following hyperoxygenation: the experience at Rambam-Elisha Hyperbaric Center in Israel, 1998-2007.

BACKGROUND: Wounds of the lower extremities are a significant public health problem, being severe and costly to treat. Adjunctive treatment with hyperbaric oxygenation (HBOT) has proven to be a useful and cost-effective means of treating ischemic wounds, mainly in diabetic patients. OBJECTIVES: To describe patients with ischemic wounds treated at the Rambam and Elisha Hyperbaric Medical Center and their wound improvement following HBOT. METHODS: We conducted a retrospective cohort study of all patients (N = 385) treated in the center during 1998-2007 for ischemic non-healing wounds in the lower extremities. RESULTS: The mean age of the patients was 61.9 years (SD 13.97). Most of them were diabetic (69.6%) and male (68.8%). Half of the subjects had a wound for more than 3 months prior to undergoing pre-HBOT transcutaneous oximetry (TcPO2) testing. Most of the wounds were classified as Wagner degree 1 or 2 (39.1% and 46.2% respectively). The median number of treatments per patient was 29. Only 63.1% of patients had continuous treatments. Approximately 20% of patients experienced mild side effects. An improvement occurred in 282 patients (77.7%) following HBOT: 15.2% fully recovered, 42.7% showed a significant improvement (and were expected to heal spontaneously), and 19.8% a slight improvement. CONCLUSIONS: HBOT can benefit the treatment of non-healing ischemic wounds (especially when aided by pretreatment TcPO2 evaluation; data not shown). Our experience shows that this procedure is safe and contributes to wound healing.

[The rate of development of myopia during hyperbaric oxygen therapy].

BACKGROUND: Hyperbaric oxygenation (HBO) is a common treatment both for emergency medicine as well as for chronic treatments. One of the most common indications for treatment is a non-healing wound due to diabetes. It is known that prolonged HBO treatments cause a myopic change in refraction. From the literature we know that the myopic shift is usually temporary, reversing back to basic refraction within a few weeks of cessation of the HBO course. There is controversy in the literature regarding the cause of refraction change, but research with animals reinforces the view that the source is the lens nucleus. PURPOSE: To measure the refractive change following 30 HBO treatments, and to quantify the rate of change. METHODS: A prospective study that included 44 eyes of diabetic patients treated with HBO in Rambam and Elisha Hyperbaric Center. Follow-up examinations were carried out every 10 treatments for spherical equivalents, sphere components, cylinder powers and axes (SPHER, SE, CYLINDER and AXIS respectively). The measurement device was an autorefractometer. A single examiner performed all the measurements; the examiner was blinded to the previous results. For each parameter, a regression equation was calculated after plotting the myopic change over time. RESULTS AND CONCLUSIONS: A positive correlation was found between HBO treatments and a myopic shift in the refraction. The correlation was statistically significant for: SPHER, SE. (0.58D, 0.61D) respectively. The change accrued from the first examination and remained throughout the follow-ups at a steady rate. Both eyes behaved similarly. The authors did not find a correlation between the myopic shift and gender, age or basic refraction. This information is vital both to clinicians, to understand the physiologic changes occurring during chronic HBO treatments, and especially to our patients, who are about to receive HBO treatments.

Hyperbaric oxygen for stage I and II femoral head osteonecrosis.

Hyperbaric oxygen therapy is a suggested joint-preserving treatment for symptomatic early-stage osteonecrosis of the femoral head. Limited studies of this treatment have been published. The goal of this study was to evaluate the effectiveness of this treatment in a relatively large patient cohort. The authors reviewed the files of 68 patients with 78 symptomatic joints with Steinberg stage I and II osteonecrosis of the femoral head. All patients were treated with hyperbaric oxygen at the authors' medical health center. Pretreatment and immediate posttreatment magnetic resonance imaging (MRI) findings were compared. On follow-up, a telephone interview was conducted to determine the survival of the joint. Modified Harris Hip Score and Short Form 12 health survey (SF-12) questionnaires of the start of treatment and at follow-up were obtained and evaluated for statistically significant differences. Half of the joints were stage 1 and half were stage II. Seventy-four joints underwent both pre- and posttreatment MRI. Eighty-eight percent of joints showed improvement posttreatment. On follow-up at a mean of 11.1±5.1 years, 54 patients (58 joints) were located and answered the questionnaires. At the time of follow-up, 93% of the joints survived. Mean Harris Hip Score improved from 21 to 81 (P<.0001), the mean physical component of the SF-12 improved from 24 to 46 (P<.0001), and the mean mental component of the SF-12 improved from 54 to 59 (P<.0001). The authors concluded that hyperbaric oxygen treatment is effective in preserving the hip joint in stage I and II osteonecrosis of the femoral head.

Hyperbaric oxygen therapy for radiation-induced haemorrhagic cystitis.

OBJECTIVE: To assess the efficacy of hyperbaric oxygen (HBO) for treating haemorrhagic cystitis. PATIENTS AND METHODS: From February 1997 to April 2004, seven patients with radiation-induced haemorrhagic cystitis were treated with HBO; they received a mean (range) of 30 (18-57) HBO treatments and the follow-up was 24 (3-53) months. RESULTS: The haematuria resolved completely in all seven patients shortly after treatment; one had an improvement but died from complications relating to cancer shortly after completing treatment, and two had recurrence of gross haematuria. They were re-treated with HBO until the haematuria resolved. CONCLUSIONS: Radiation-induced haemorrhagic cystitis can be treated successfully with HBO primarily or after failure of standard regimens. This method was well tolerated even in patients debilitated by advanced cancer and blood loss. Long-term remission is possible in most patients, and re-treatment effectively manages recurrent bleeding.

Hyperbaric oxygen and radiotherapy.

BACKGROUND: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. METHOD: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action "Hyperbaric Oxygen Therapy" started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. RESULTS: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. CONCLUSION: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org.