Stress-induced hormonal and mood responses in scuba divers: a field study.

The majority of injuries in scuba-divers are attributable to inappropriate behavior under stressful diving conditions, predominantly involving panic reactions emerging from elevated levels of anxiety. Divers with an elevated level of anxiety and poor coping are at higher risk of developing panic reactions than those possessing more adequate stress-coping-mechanisms. In the comparison of two extreme groups of seven divers each with opposite stress coping strategies, prolactin was found to be a hormonal marker with a significant increase in the sub-group of the stress-controllers. This hormonal response was observed in a recreational and a stressful dive, and in the latter with a more distinct elevation. Along with the self-reported emotional conditions under immersion, these data suggest that an increased prolactin level reflects a state of elevated physical and mental activation and vigilance. Facing a stressful situation subjects with more emotional concern and the tendency to surrender react by "blunted responses" and show significantly lower elevations of the prolactin levels in contrast to subjects with the very opposite psychological features. The other observed somatic parameters (epinephrine, norepinephrine) showed significant increases during and after dives (with the exception of saliva cortisol), however without any significant group difference.

Acute effects of combined photodynamic therapy and hyperbaric oxygenation in lung cancer--a clinical pilot study.

BACKGROUND AND OBJECTIVE: Photodynamic tumor therapy (PDT) is based upon a photochemical reaction that is limited by the availability of molecular oxygen in the target tissue. The use of hyperbaric oxygenation (HBO) increases the amount of oxygen available for the process may thereby enhance the efficacy of PDT. We investigated the acute effects on tumor stenosis after combined PDT/HBO. PATIENTS AND METHODS: Thirty patients (22 males, 8 females, mean age: 68.8 years; range: 44-78 years) with inoperable non-small cell bronchogenic carcinoma and endobronchial stenosis were studied prospectively. Photosensitization was carried out using a hematoporphyrin-derivative 2 mg/kg BW 48 hours prior to PDT. The light dose was calculated as 300 J/cm fiber tip. The assessment of outcome 1 and 4 weeks after PDT/HBO was performed by endoscopy, chest X-ray, spirometry, laboratory parameters, subjective report of dyspnea, and Karnofsky performance status. RESULTS: At one and four weeks after the treatment, the patients felt a significant improvement of dyspnea and hemoptysis along with an objective subsiding of poststenotic pneumonia, though spirometric parameters revealed no significant difference. A significant reduction of tumor stenosis (P < 0.05) and an improvement of the Karnofsky performance status (P < 0.05) were documented 1 and 4 weeks after PDT/HBO. No therapy related complications were observed. CONCLUSIONS: Although the small number of patients does not allow to draw definitive conclusions to be drawn, the results suggests that combined PDT/HBO represents a new, safe, and technically feasible approach. It enables efficient and rapid reduction of the endoluminal tumor load and helps conditioning the patient for further treatment procedures.

Combined photodynamic therapy and hyperbaric oxygenation in carcinoma of the esophagus and the esophago-gastric junction.

OBJECTIVES: The photochemical reaction of photodynamic therapy (PDT) depends on the presence of molecular oxygen. Due to anoxic regions in tumor tissue and vascular shutdown during PDT the efficiency is limited. Therefore, the use of hyperbaric oxygen which increases the oxygen in tumor tissue, as well as the amount of singlet oxygen, may enhance the efficiency of PDT. PATIENTS AND METHODS: After diagnostic work-up, photosensitization was carried out with a hematoporphyrin-derivate 2 mg/kg BW 48 h prior to PDT. The light dose was calculated as 300 J/cm fiber tip. Thirty-one patients were treated by PDT alone and 44 patients received PDT under hyperbaric oxygen at a level of two absolute atmospheric pressure. RESULTS: Improvement regarding stenosis-diameter could be obtained in both treatment arms with no significant difference (P=0.82). The dysphagia-score and tumor-length also decreased in both groups and showed a significant difference in favour of the PDT/HBO-group (P=0. 0064 and P=0.0002, respectively). The median overall survival for the PDT-group was 7 months and for the PDT/HBO-group 12 months (P=0. 0098). CONCLUSION: According to this prospective non-randomized study, combined PDT/HBO represents a new approach in the treatment of esophageal and cardia cancer which appears to have enhanced the efficiency of PDT.

Review of severe osteoradionecrosis treated by surgery alone or surgery with postoperative hyperbaric oxygenation.

We reviewed 41 patients with osteoradionecrosis of the mandible. Each patient was treated by radical resection followed by external beam irradiation. The diagnosis of infected osteoradionecrosis was confirmed clinically, radiologically, and histologically. After operation had failed, 20/41 were given hyperbaric oxygen (HBO) as in 'salvage' treatment. Daily sessions of HBO 2.5 ATA for 60 minutes (mean: 29 sessions) were given. The other 21 patients were treated by operation and antibiotics alone. HBO group (n = 20): The overall success rate for HBO after operation had failed was 13/20. Repeated debridement as first-line treatment followed by postoperative HBO was successful in 12/19. In seven of 19 patients, partial mandibulectomy and microvascular transplantation were required as second-line treatment, and this was successful in five. Primary partial mandibulectomy and microvascular transplantation followed by HBO was successful in 1 patient. Non-HBO group (n = 21): Repeated debridement was successful in 10/11 patients. Partial mandibulectomy was required as second-line treatment in the remaining one. In the other 10, partial mandibulectomy and microvascular transplantation were successful as first-line treatment in four. In the remaining six, further surgical intervention became necessary and were successful for 5-17 months (mean: 13). With a success rate of 13/20, we do not recommend HBO for the treatment of osteoradionecrosis.

Hyperbaric oxygen and photodynamic therapy in the treatment of advanced carcinoma of the cardia and the esophagus.

BACKGROUND AND OBJECTIVE: The photochemical reaction of photodynamic therapy (PDT) depends on the presence of molecular oxygen. Because of anoxic regions in tumor tissue and vascular shutdown during PDT, the efficiency is limited. Therefore, the use of hyperbaric oxygen, which increases the oxygen in tumor tissue, as well as the amount of singlet oxygen, may enhance the efficiency of PDT. STUDY DESIGN/MATERIALS AND METHODS: After diagnostic work-up, photosensitization was carried out with a hematoporphyrin-derivate 2 mg/kg body weight 48 hours before PDT. The light dose was calculated as 300 J/cm of fiber tip. Twenty-three patients were treated by PDT alone and 29 patients received PDT under hyperbaric oxygen at a level of two absolute atmospheric pressures. RESULTS: Improvement regarding dysphagia and stenosis-diameter could be obtained in both treatment arms with no significant difference (P = 0.43 and P = 0. 065, respectively). The tumor length also decreased in both groups and showed a significant difference in favour of the PDT/HBO group (P = 0.002). The mean overall survival was 11.3 months. The mean survival time for the PDT group was 8.7 months and for the PDT/HBO group 13.8 months (P = 0.021). CONCLUSION: According to this pilot study, combined PDT/HBO represents a new approach in the treatment of esophageal and cardia cancer, which appears to have enhanced the efficiency of PDT.

Does hyperbaric oxygen enhance the effect of photodynamic therapy in patients with advanced esophageal carcinoma? A clinical pilot study.

BACKGROUND AND STUDY AIMS: Experimental studies have shown that the cytotoxicity of porphyrins and related substances is mediated mainly by singlet oxygen and that hypoxic cells are less affected by porphyrins and light. In a clinical pilot study we assessed the use of photodynamic therapy (PDT) under hyperbaric oxygen (HBO), compared with PDT under normobaric conditions, in patients with advanced esophageal carcinoma. PATIENTS AND METHODS: After diagnostic work-up and staging, photosensitization in all patients was carried out using hematoporphyrine derivate (HpD) (2 mg/kg bodyweight 48 hours prior to PDT). We then applied light at 630 nm (KTP-Nd: YAG laser with DYE box) at dose of 300 J/cm, delivered by a fiber with a radial light-diffusing cylinder (length 1 cm), inserted through the biopsy channel of the endoscope. Of the patients, 14 (12 with stage III cancers, and two with stage IV cancers) were treated by PDT alone, and 17 patients (15 with stage III cancers, and two with stage IV cancers) received PDT under HBO at a level of 2 absolute atmospheric pressures (ATA). Transcutaneous PO2 levels of 500-750 mm Hg under HBO, compared with transcutaneous PO2 levels of 60-75 mm Hg under normobaric conditions, were measured. RESULTS: Improvements regarding dysphagia and stenosis diameter were obtained in both treatment arms with no significant differences (P = 0.36 and 0.14, respectively). The tumor length also decreased in both groups and showed a significant difference in favour of the PDT/ HBO group (P = 0.002). Kaplan-Meier statistics showed median overall survival for the PDT group and the PDT/HBO group as 7.0 and 12 months respectively. The 12-month survival rate was 28.6% for the PDT group and 41.2% for the PDT/HBO group. Logrank test showed a difference in survival in favor of the PDT/HBO group (P = 0.059). No major treatment-related complication occurred, and the 30-day mortality rate was 0%. CONCLUSIONS: Combined PDT/HBO represents a new approach in the treatment of esophageal cancer which, in this pilot study, appears to have enhanced the efficiency of PDT.

Treatment of cerebral radionecrosis by hyperbaric oxygen therapy.

Clinically observed adverse radiation effects (ARE) are rather uncommon, but modern imaging reveals that they are more common after radiosurgery than previously believed. Little is known about the pathogenesis, and current treatment is mostly empirical. The benefit of hyperbaric oxygen therapy (HBO) on radiation-induced bone and soft tissue necrosis is known in lesions in the maxillofacial area, the mouth and in the head and neck. HBO raises the tissue pO2 and initiates a cellular and vascular repair mechanism. This forms the basis for the hypothesis that it might also help alleviate the results of cerebral radionecrosis. This study is a preliminary attempt to test this hypothesis. Two patients with arteriovenous malformations (AVMs) were chosen for the study. They had been treated with Gamma Knife radiosurgery (GKRS) and had developed imaging signs consistent with ARE. They were treated by breathing 100% oxygen at 2.5 atmospheres absolute (250 kPa) in sessions of 60 minutes per day. This treatment was repeated 40 times in cycles of ten sessions. Both responded well to HBO, one lesion disappeared and the other was reduced significantly in size. No adjuvant steroids were given. These results give evidence that HBO has a potential value in treating ARE but further experience will be needed to confirm its definite benefit.