Effect of adjuvant hyperbaric oxygen on healing of cartilage lesions treated with microfracture: an experimental study in rats.

PURPOSE: The purpose of this experimental study was to investigate the effect of hyperbaric oxygen (HBO2) therapy combined with microfracture technique in the treatment of cartilage lesions. METHODS: Adult Wistar rats (n=44) were divided into six groups. In Groups A, B, C and D, ICRS* (* International Cartilage Repair Society) grade 4 cartilage lesions were made on the femoral sulcus of both knees. Lesions were microfractured on the left knees; the right knees had no further procedure. Groups E and F had no surgery. Groups A, C and E received HBO2 therapy once a day, six days a week postoperatively. Groups B, D and F had no HBO2 therapy. The animals in Groups A, B, E and F were sacrificed after two weeks; Groups C and D were sacrificed after four weeks. Semiquantitative scale - including filling of defect (microfracture hole), reparative tissue thickness, cell morphology and subchondral bone maturation - was used for evaluation. The Mann-Whitney test was used to compare individual and total scores. RESULTS: Total scores of the two-week group with adjuvant HBO2 therapy were significantly higher (P=0.0007) than the two-week standard treatment group. Except for subchondral bone maturation, individual scores were significantly higher in the two-week group with adjuvant HBO2 therapy. Total scores of the four-week groups were similar. Among individual scores of the four-week groups, filling of the defect (microfracture hole), and subchondral bone maturation were significantly higher (P=0.01, P=0.03) in groups with adjuvant HBO2 therapy. CONCLUSIONS: Adjuvant HBO2 therapy accelerates the healing process of cartilage lesions treated with microfracture in rats.

Can amputation be prevented in diabetic foot? Interdisciplinary approach to diabetic foot: a case report.

Diabetic foot ulcers may result in loss of an extremity and may even lead to mortality. The use of comprehensive foot care programs which include early screening and evaluation of problems, foot care education, preventive therapy and referral to specialists has been shown to reduce amputation rates by 49-85 [percent]. A 51-year-old woman with Type 2 diabetes under surveillance for nine months was referred from the emergency department. She presented with an entirely inflamed right foot with ulcer covering two-thirds proximal of the foot for 30 days' duration. There was extensive edema as well as cellulitis extending to the knee, fluctuating abscesses and lymphangitis to the ankle. Magnetic resonance imaging showed extensive abscesses and edema in foot compartments. After a further four weeks of antibiotics, 80 sessions of hyperbaric oxygen therapy shrank the wound from 15x15x2 cm to 3x3x0.2 cm. The wound was closed with a split thickness graft, and healing completed four months after presentation. Patients with diabetic foot deserve clinical evaluations of the whole body rather than a regional treatment. An interdisciplinary approach involving both medical and surgical treatment options should be conducted according to this perspective. It could be effective in lowering major amputation rates and even preventing amputations. Simultaneously administered effective debridement methods, utilization of minor amputations for necrotic tissue and lowering the infectious load with appropriate antibiotics, aggressive wound care with the appropriate wound care products, unconventional treatment methods like hyperbaric oxygen treatment and negative pressure wound care may help reduce amputation levels and save extremities.

The prevalence of electrocardiogram abnormalities in professional divers.

BACKGROUND: The underwater environment presents physiological challenges for the cardiovascular, renal and pulmonary systems. Increases in external hydrostatic pressure reduce the capacity of the venous compartment and cause blood to move toward the lung. The aim of this study was to evaluate retrospectively electrocardiographic (ECG) changes in a cohort of professional divers. METHODS: Between January 2009 and January 2012, 225 randomly selected professional divers, 204 male (91%) and 21 female (9%) attended our clinic for their biannual diving medical assessment. Their ECG records were evaluated retrospectively. RESULTS: The most common ECG abnormality observed was incomplete right bundle branch block (IRBBB) in 30 divers (13.3%). Eleven divers (4.9%) showed right QRS axis deviation (seven with IRBBB). Six divers had a sinus tachycardia; in four divers there was early repolarization; three divers had ventricular extrasystoles; one diver had ST elevation in lead V3; there was one with sinus arrhythmia and another with T-wave inversion in leads V2, V3 and aVF. These ECG changes were evaluated retrospectively by a cardiologist who made various recommendations for further review including bubble contrast echocardiography for IRBBB. CONCLUSIONS: No serious ECG abnormalities were identified, but IRBBB should be further investigated because of its association with persistent (patent) foramen ovale. Rapid cardiological review of ECGs could be achieved using modern communications technology, such as telecardiography, and further clinical investigations directed by specialist recommendation arranged promptly if indicated.

Evaluation of cognitive performance in professional divers by means of event-related potentials and neuropsychology.

OBJECTIVE: We investigated whether professional air diving with no decompression illness causes any long-term changes in cognitive functions. METHODS: The all-male participants consisted of 18 healthy control (HC) volunteers and 32 divers. Divers were divided into two subgroups as moderate exposure group, Divers-I (DI) and extensive exposure group, Divers-II (DII). Participants were administered a comprehensive neuropsychological battery and event-related potentials (ERPs) were recorded while they performed auditory oddball task and visual continuous performance test (CPT). RESULTS: P3 waves in oddball and CPT were significantly attenuated and peak latencies were prolonged in both diver groups compared with HC. Amplitude decrements in CPT P3 were graded with respect to level of diving exposure. Neuropsychologically, DII group displayed significantly poorer performance than HC and DI groups in measures of visuo-constructional and visual long-term memory tests. DI group performed better than HC group in some measures of planning ability. CONCLUSIONS: Most of the changes in neurophysiological measures and poorer neuropsychological performance were found in DII group, and this might be interpreted as a red flag for the reflection of the slowly progressing deleterious effects of silent bubbles in brain function. SIGNIFICANCE: This study reports impairments in certain neuropsychological measures and apparent neurophysiological markers pointing to slow cognitive decline referring to long-term effects of diving.

Decompression sickness cases treated with recompression therapy between 1963 and 1998 in Turkey: review of 179 cases.

The purpose of this study was to review the cases diagnosed as decompression sickness (DCS) with recompression therapy treament between 1963 and 1998 in Turkey. The records of 179 cases were analyzed for age, gender, type of DCS, presenting signs and symptoms, time to onset of symptoms, time to recompression therapy, recompression table used, total number of treatments and outcomes. The diving depth on the day of injury ranged between 60 and 215 fsw (18 and 65 msw). The symptoms developed during ascent or within 10 minutes after surfacing in 47% of divers and within the first hour in 87% of the divers. The most frequent symptom was sensory loss in the extremities. The dive before the symptoms was a repetitive dive in 50% of the cases and the diagnosis was Type II DCS in 79% of these divers. Most of the divers (84%) received recompression therapy after a delay of more than 12 hours. Healing rate was 68% with the air recompression tables and 86% with the oxygen tables. Repetitive dives were associated with a higher incidence of Type II DCS than single dives (79% and 66%, respectively). The results using recompression tables with oxygen were more successful than the treatment with air tables.

Is HBOT treatment effective in recovering zone of stasis? An experimental immunohistochemical study.

Studies aimed at recovering the zone of stasis are one of the major issues of experimental burn studies. Hypoxia and oedema at that zone may cause irreversible changes. Due to anti-oedematous and antihypoxic effects of hyperbaric oxygen treatment (HBOT), it may be beneficial in recovering the zone of stasis. We performed an experimental study using 20 Sprague-Dawley rats, each weighing 350-450 g. The rats were first divided into two groups as 24h and 5 days. Subsequently, control and treatment groups (five rats in each group) were formed. For burn wounds, we used the burn comb model, which was described by Regas and Ehrlich. In the treatment group, 2.5 ATA HBOT was applied for 90 min twice daily. A 0.8-cm punch biopsy was performed and samples for histological examination were taken from the centre of burn area. The rats were sacrificed by administering '3 mci technetium-99m methoxy butyl nitrite' ((99)Tc(m) MIBI) through the femoral vein. Biopsy materials were evaluated by histological and immunohistochemical methods. Dorsal skin fragment, excised to 1cm margin, was imaged by scintigraphic measurements with a gamma camera. Wet and dry weight measurements of excised skin fragments were taken. As a result, HBOT showed a positive effect at the cellular level in the first 24h. It increased recovery potential by augmenting neovascularisation and decreasing oedema in the 5-day group.

Hyperbaric oxygen therapy as an anti-infective agent.

Hyperbaric oxygen therapy (HBOT) involves inhalation of 100% oxygen at supra-atmospheric ambient pressure. HBOT is used as either a primary or adjunctive treatment in the management of infections such as gas gangrene, necrotizing fasciitis, diabetic foot infections, refractory osteomyelitis, neurosurgical infections and fungal infections. HBOT acts as a bactericidal/bacteriostatic agent against anerobic bacteria by increasing the formation of free oxygen radicals. HBOT restores the bacterial-killing capacity of leukocytes in hypoxic wounds by increasing tissue oxygen tensions. In addition, HBOT acts synergistically with a number of antibiotics. This article reviews the anti-infective effects of HBOT and the use of HBOT in the treatment of certain infectious diseases.

Sponge divers of the Aegean and medical consequences of risky compressed-air dive profiles.

Historically, Turkey once had a substantial number of professional sponge divers, a population known for a relatively high incidence of diving-related conditions such as decompression sickness (DCS) and dysbaric osteonecrosis (DON). Sponge diving ended in the mid-1980s when nearly all of the sponges in the Aegean and Mediterranean Seas contracted a bacterial disease and the occupation became unprofitable. We reviewed the records of Turkish sponge divers for information on their level of knowledge, diving equipment, dive profiles, and occupational health problems. Information was collected by: 1) interviewing former sponge divers near Bodrum, where most of them had settled; 2) reviewing the relevant literature; and 3) examining the medical records of sponge divers who underwent recompression treatment. These divers used three types of surface-supplied equipment, including hard helmets, Fernez apparatus, and hookahs; the latter were preferred because they allowed divers the greatest freedom of movement while harvesting sponges underwater. These divers used profiles that we now know involved a high risk for DCS and DON. We were able to access the records of 58 divers who had received recompression treatment. All of the cases involved severe DCS and delays from dive to recompression that averaged 72 h. Complete resolution of symptoms occurred in only 11 cases (19%). Thus, we were able to document the several factors that contributed to the risks in this occupational group, including unsafe dive profiles, resistance to seeking treatment, long delays before recompression, and the fact that recompression treatment used air rather than oxygen.

Dysbaric osteonecrosis screening in Turkish Navy divers.

INTRODUCTION: Dysbaric osteonecrosis (DON) is regarded as an occupational disease for caisson workers, commercial, and military divers. Magnetic resonance imaging (MRI) was suggested for the surveillance of military divers for DON. This study aimed to determine the prevalence of DON in Turkish Navy divers. METHODS: The shoulder, hip, and knee joints of 106 male divers were screened for DON with MRI. A questionnaire was used to obtain information about subjects' medical history and diving experience. RESULTS: The mean age of divers was 34.3 +/- 5.8 yr. The divers had spent an average of 12.1 +/- 6.1 yr at their occupation. The average of total hours of diving was 834 +/- 458 h. The maximum diving depth was 53.0 +/- 18.4 m (175 +/- 61 ft) and the average diving depth was 13.3 +/- 8.4 m (44 +/- 28 ft). MRI examinations of divers did not reveal bone lesions consistent with osteonecrosis. DISCUSSION: We concluded that the risk of DON is very low for military divers who strictly obey the decompression rules and who undergo periodic medical examination. The use of MRI for routine screening of military divers is not justified.

Dysbaric osteonecrosis in experienced dive masters and instructors.

INTRODUCTION: Dysbaric osteonecrosis (DON) is a type of aseptic bone necrosis of long bones such as the humerus, femur, and tibia. It is observed in workers who perform in high-pressure environments. METHODS: There were 58 volunteer divers included in this study who had performed at least 500 dives, were working as a dive master or instructor, had never performed industrial and commercial dives, and did not have a diagnosis of osteonecrosis. Radiological evaluation was performed according to the guidelines suggested by The British Research Council Decompression Sickness Panel. A total of eight X-rays were taken per patient. When suspicious lesions were detected, MRI of the region was performed. RESULTS: Of the 58 divers, 2 were eliminated because of inadequate X-ray studies. A total of 18 DON lesions were detected in 14 of 56 (25%) divers. Age was the only variable independently associated with the development of DON (P < 0.05). DISCUSSION: The DON prevalence of 25% in this study is high considering the dive instructors had thorough diving training and strictly practiced the decompression rules. We believe this high prevalence is a result of frequent and sometimes deep dives for many years. Our findings raise the question of whether these divers can be seen as "sports divers" or should be seen as "occupational divers." If the latter description is approved, dive masters and instructors should be kept under periodic screening for DON lesions just like professional commercial divers to help reduce the morbidity associated with this disease.

Procalcitonin as a diagnostic aid in diabetic foot infections.

The diagnosis of diabetic foot infection (DFI) is usually a challenge to the clinician. Procalcitonin (PCT), a 116-amino acid propeptide of calcitonin, is a new marker of bacterial infections and sepsis. We evaluated the serum value of PCT as a marker of bacterial infection in diabetic patients with foot ulcers. Forty-nine diabetic patients with foot ulcers were consecutively enrolled into the study. DFI was diagnosed clinically by the presence of purulent secretions or at least two of the symptoms of inflammation including redness, warmth, swelling, and pain. According to these criteria, DFI was determined in 27 patients (DFI group) and not detected in 22 patients (NDFI group). The blood samples were taken for biochemical analysis on admission. PCT, white blood cell count (WBC) and erythrocyte sedimentation rate (ESR), but not C-reactive protein (CRP), was found significantly higher in DFI group compared with NDFI group. The best cut-off value, sensitivity and specificity were 0.08 ng/ml, 77% and 100% for PCT, 32.1 mg/dl, 29% and 100% for CRP, 8.6 10(9)/L, 70% and 72% for WBC and 40.5 mm/h, 77% and 77% for ESR, respectively. The area under the receiver operating characteristic curve for infection identification was greatest for PCT (0.859; p < 0.001), followed by WBC (0.785; p = 0.001), ESR (0.752; p = 0.003), and finally CRP (0.625; p = 0.137). These results suggest that PCT may be a useful diagnostic marker for DFI. Additional research is needed to better define the role of PCT in DFI.

Investigation of the effect of hyperbaric oxygen on experimental cyclosporine nephrotoxicity.

Hyperbaric oxygen interacts with drugs which patients use concurrently with hyperbaric oxygen treatment, which may cause in potentiation or inhibition of both therapeutic and toxic effects. We examined the effect of hyperbaric oxygen therapy on experimental cyclosporine A nephrotoxicity. The study comprised four groups of rats: a control group, a cyclosporine A group (25 mg/kg/day intraperitoneally for four days), a hyperbaric oxygen group (60 min. every day for four days at 2.5 atmospheric pressure), and a cyclosporine A+hyperbaric oxygen group (CsA 25 mg/kg/day intraperitoneally for four days+hyperbaric oxygen for 60 min. every day for four days at 2.5 atmospheric pressure). Hyperbaric oxygen did not alter biochemical parameters. Cyclosporine A increased serum urea and serum creatinine levels and decreased creatinine clearance. In the cyclosporine A+hyperbaric oxygen group serum urea level increased more than in the cyclosporine A group. Cyclosporine A increased tubular epithelial cell apoptosis and necrosis score values. The numbers of apoptotic cells in proximal tubule epithelial cells in the cyclosporine A+hyperbaric oxygen group were significantly higher than those of the cyclosporine A group. We recommend that renal functions of the patients receiving cyclosporine A should be monitored during hyperbaric oxygen therapy.

Comparison of pulmonary autopsy findings of the rats drowned at surface and 50 ft depth.

INTRODUCTION: When a body is recovered from the water after a fatal SCUBA diving accident, it is useful to know if the diver was under pressure or not when he/she took his/her last breath, in order to determine the cause and manner of the death. If the victim was under pressure, the air remained in the lungs of the diver will be equal to the environmental pressure. If the body comes to the surface, the air in the lung will expand according to the Boyle's Gas Law and give mechanical damage to the surrounding tissues, due to decreases in environmental pressure. We designed an experimental study to see the difference in pulmonary autopsy findings of the rats that drowned under normobaric and hyperbaric conditions. METHOD: Forty five male, 250-300 g, Sprague Downey adult rats were divided into three groups. Two groups of rats were drowned under normobaric conditions (Groups DS Group DSS) and the third group at 50 ft pressure (Group DD). The pulmonary autopsy findings of the groups were compared. In the light microscopy, the number of the microscopic fields (x10) containing at least one emphysematous area with longitudinal dimension greater than 300 micro m were compared among the groups. RESULTS: The gross examination revealed a prominent swelling of the lungs in all rats in the Group DD, in comparison to that of the Groups DS and DSS. The number of the microscopic fields, which included at least one emphysematous area with longitudinal dimension greater than 300 micro m out of 150 fields from each of the groups DS, DSS and DD, were 88, 101 and 115 respectively. The difference between the group DS and DD was found to be statistically significant. CONCLUSION: We conclude that in investigating the fatal diving accidents, pulmonary autopsy findings give valuable information whether the death occurred at the surface or at the depth.

Aural barotrauma in submarine escape: is mastoid pneumatization of significance?

OBJECTIVE: Submarine escape training is carried out by preselected, healthy young men under strictly controlled conditions regarding exposure to pressure and the rate of pressure change. This provides a unique opportunity to investigate the relations between middle ear characteristics and susceptibility to barotrauma while avoiding possible confounding parameters. We examined a possible association between mastoid pneumatization and middle ear barotrauma (MEB) in submarine escape trainees. STUDY DESIGN: Cross-sectional, parallel-group design. METHODS: Sixty-six subjects aged 19 to 28 participated in the study. The escape simulation included pressurization to 30 or 60 feet followed by a buoyant ascent to the surface. Subjects were evaluated for MEB after each ascent. A Schuller's mastoid radiograph was taken for the evaluation of mastoid pneumatization. RESULTS: Fifteen (23%) of the subjects suffered from MEB, and 6 (40%) of them had bilateral involvement. Repeated impedance audiometry after the completion of a successful ascent revealed a significant increase in middle ear compliance. Schuller's radiographs were obtained from 49 (74%) of the subjects. Of these radiographs, 16 (16%) were of ears that had suffered MEB. Mastoid pneumatization for all ears approached a normal Gaussian distribution, with a mean area of 9.58 cm. The mastoid areas and the proportion of ears with mastoid pneumatization at the extremes of the study population did not differ between barotrauma and no-barotrauma ears. CONCLUSION: In a population with no history of recurrent or chronic otitis media and normal tympanic membrane morphology and compliance, the amount of mastoid pneumatization probably represents merely the normal distribution of variation in organ size and is not related to the ability to equalize pressure in the middle ear.

Adjunctive hyperbaric oxygen therapy contributes healing in electrical injury: a case report of high voltage electrical injury.

In electrical injuries, new treatment modalities and guidelines are needed for improving clinical outcome and the survival of damaged tissue. Although there is no published study about hyperbaric oxygen (HBO) therapy for electrical injury in the literature, it is indicated in conditions, which may contribute to the clinical presentation of electrical injury such as thermal burns, crush injuries, necrotizing soft tissue infections, problematic wounds and compromised skin grafts and flaps. An 11-year-old child with high voltage electrical injury treated with adjunctive hyperbaric oxygen for 90 minutes twice a day at 2,4 ATA for one week, then once a day for six days for a total of 20 sessions was presented to demonstrate the beneficial effects of hyperbaric oxygen therapy initiated before irreversible damage had taken place. Although hyperbaric oxygen therapy was initiated rather late, when the most effective window for intervention had already past, HBO was effective in fighting against necrosis, infection and tissue loss. Adjunctive HBO therapy is suggested for electrical injuries for its contribution to healing. In order to see the favourable effects of HBO, it is better to start the treatment within the first 24 hours following injury.

Seizure incidence in 80,000 patient treatments with hyperbaric oxygen.

INTRODUCTION: Hyperbaric oxygen treatment (HBOT) involves some risk of central nervous system (CNS) oxygen toxicity, which may be revealed by various signs and symptoms including seizures in patients breathing O2 at pressures of 2 ATA or higher. The aim of this study was to determine the incidence of such seizures in the Underwater and Hyperbaric Medicine Departments of two university hospitals. METHODS: We retrospectively evaluated 80,679 patient-treatments for 9 clinical indications to determine the incidence of seizures attributable to CNS O2 toxicity. Because different protocols were used for HBOT, the treatments were studied in four groups according to the chamber type used and the medical facility at which it was located. RESULTS: Only 2 seizures were documented, yielding an incidence of 2.4 per 100,000 patient-treatments. Both cases occurred in a multiplace chamber pressurized to 2.4 ATA with O2 delivered by mask for three x 30 min with 5-min air breaks. DISCUSSION: The seizure incidence reported here is lower than other studies published in the literature. The delivery of O2 by mask rather than hood may be a factor. Nevertheless, it appears that the risk of seizures due to CNS O2 toxicity during HBOT is very low as long as appropriate exclusion criteria and treatment profiles are used.

Dysbaric osteonecrosis screening in submarine escape instructors.

INTRODUCTION: Dysbaric osteonecrosis (DON) is an avascular bone necrosis that can be seen in divers and compressed air workers. Submarine escape instructors constitute a specific group who are exposed to hyperbaric conditions with a constant profile. METHODS: We screened 21 Turkish Navy submarine escape instructors and evaluated 147 skeletal radiographs for dysbaric osteonecrosis. Two instructors who had suspicious DON lesions on the X-rays underwent examination by MRI of the suspected sites. RESULTS: We found no evidence of DON in the radiographs and MRIs of the submarine escape instructors. DISCUSSION: We concluded that the risk of DON is very low for submarine escape instructors who work at the Submarine Escape Training Tower (SETT) at a depth of 60 ft and who strictly obey the decompression rules.