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Objectives: There are limited data regarding the safety of cochlear implants during exposure to pressure changes associated with scuba and hyperbaric oxygen therapy. There are no data regarding the effects of barometric pressure changes on preserved low-frequency hearing after cochlear implantation. This case report evaluates the effect of barometric pressure changes on preserved low-frequency hearing after cochlear implantation. Patient: This is a case report of a patient who underwent successful cochlear implantation with postoperative preservation of residual low-frequency hearing. Interventions: 20 scuba dives up to depths of 92 feet (3.8 atmospheres absolute).Main outcome measures: Preservation of hearing and maintained integrity of the implant. Results: Audiometric testing both before and after scuba shows no change in hearing thresholds. The internal receiver-stimulator of the cochlear implant was unaffected by prolonged and repeated pressures up to approximately 3.8 atmospheres absolute. The patient had no adverse middle ear effects during or after the dives, and no evidence of inner ear barotrauma or decompression sickness as a result of the elevated pressures. Conclusions: This is the first report of preserved hearing after cochlear implantation being maintained following scuba diving, and corroborates previous literature showing that exposure to increased pressures with a cochlear implant in situ is safe without ..
We evaluated the efficacy of hyperbaric oxygen (HBO2) therapy used as a supplement to the first-line medical treatment of sudden sensorineural hearing loss (SSNHL). We tested 68 patients suffering from SSNHL within seven days of hearing loss: 21 patients received the standard treatment protocol of our department (control group) and 47 individuals were treated with an additional application of HBO2 therapy. Treatment success was assessed using pre- and post-treatment audiograms. Outcomes of our study showed a statistically significant improvement in auditory threshold in all frequency groups for the HBO2 group (P < 0.001), whereas in the control group the statistically significant mean auditory gain was observed only for the frequency zone 1,000 to 2,000 Hertz (P = 0.01). Furthermore, the rate of hearing gain in the HBO2 group was more than doubled (61.7%) compared to the control group (28.6%). Complete recovery of the hearing gain in the control group was observed only in the first two frequency groups (14.29%; 4.76%; 0.00%), whereas in the HBO2 group complete recovery was seen in all the frequency groups (19.15%; 21.13%; 6.38%) as well as in the whole frequency range (6.38%). The efficiency of both treatment protocols was statistically significant (P < 0.001) in both groups ..
Nuclear factor kappa B (NF-κB) is the critical transcriptional factor in the pathogenesis of acute lung injury (ALI). NF-κB regulates the expression changes of inflammatory factors such as tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and interleukin 6 (IL-6). In a previous study we showed that decompression sickness (DCS) caused by simulated unsafe fast buoyancy ascent escape (FBAE) could result in ALI, which was characterized by expression changes of inflammatory factors in rat lung tissue. The purpose of the present work was to study the roles of NF-κB and TNF-α in the process of DCS-induced rat lung injury caused by simulated unsafe FBAE. The research methods aimed to detect the rat lung tissue messenger ribonucleic acid (mRNA) and protein level variations of NF-κB, inhibitory κB (IκB), TNF-α, IL-1β, IL-6, IL-10 and IL-13 by using pretreatment of the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) and TNF-α antibody (Ab). Our experimental results demonstrated that PDTC could improve the survival rate of the rats with DCS caused by unsafe FBAE more effectively than TNF-α Ab. However, the inhibition of TNF-α Ab on the nuclear translocated protein expression of NF-κB was more effective than PDTC. Both PDTC and TNF-α Ab can abrogate the increment of the ..
Purpose: Experiments have shown that hyperbaric oxygen (HBO2) therapy reduces cyanide-induced cerebral distress. The exact mechanism behind HBO2’s neuroprotective effect is unknown, but has been proposed to be mediated by an increased neuronal nitric oxide (NO) bioavailability, which may compete with cyanide for the active site of cytochrome oxidase in the mitochondrial respiratory chain. We hypothesized that the ameliorating effect of HBO2 is caused by an increased bioavailability of NO, which can be attenuated by injection of the selective neuronal NO synthase inhibitor, 7-nitroindazole, preceding the HBO2 procedure. Methods: A total of 41 anesthetized female Sprague-Dawley rats were allocated to four groups: 1) vehicle [1.2 ml isotonic NaCl via intra-arterial administration]; cyanide [5.4 mg/kg potassium CN (KCN) intra-arterial] + 7-nitroindazole [25 mg/kg 7-nitroindazole via intraperitoneal injection];  cyanide+7-nitroindazole + HBO2 [284 kPa for 90 minutes]; cyanide + 7-nitroindazole + normobaric oxygen [101.3 kPa for 90 minutes].  Cerebral interstitial lactate, glucose, glycerol and pyruvate were evaluated by means of microdialysis. Results: HBO2 during inhibition of nNOS worsened cerebral metabolism compared to both solely CN-intoxicated animals and normobaric oxygen-treated animals. This was indicated by elevated lactate (in mM; 0.85 vs. 0.63 and 0.42, P=0.006 and P<0.001, respectively), glycerol (in mM; 46 vs. 17 and 14, both P<0.001), glucose (in ..
Introduction: Acute lung injury (ALI) is generally caused by oxidative damages and pulmonary overinflammations. Hyperbaric oxygen preconditioning (HBO2-PC) has been proven protective against oxidative-stress-related injuries. In this study, we investigated the effect of HBO2-PC on lipopolysaccharide (LPS)-induced ALI in rats. Methods: Thirty-two Sprague-Dawley rats randomly assigned into Sham, HBO2-PC, ALI and HBO2-PC+ALI groups (eight in each group) were sacrificed at 12 hours after the injection of LPS. The severity of ALI in rats was assessed in terms of histopathological changes in addition to wet/dry weight ratios. The levels of tumor necrosis factor-? (TNF-?), interleukin (IL)-6 and IL-1β in serum and lung homogenates were measured by enzyme-linked immunosorbent and qRT-PCR assays. Activities by hydrogen peroxide (H2O2), malondialdehyde (MDA), myeloperoxidase (MPO) as well as superoxide dismutase (SOD) in rat lungs were tested for neutrophil infiltration. Meanwhile the oxidative stress molecular markers nuclear factor-kappa B(NF-κB) p65 and nuclear factor erythroid 2-related factor 2 (Nrf2), together with its downstream heme-oxygenase 1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) were also quantified. Results: HBO2-PC significantly alleviated LPS-induced ALI, lowered the lung injury scores, reduced lung water content, and reduced H2O2, MDA levels as well as MPO activity, while simultaneously improving the arterial partial oxygen pressure (PaO2) ..
Hookah diving is a fishing method used in many small-scale fisheries in the Gulf of Mexico and the Caribbean Sea, as well as in many coastal fisheries around the world. Many high-value species like sea cucumber and spiny lobster, among others, are harvested via hookah diving. However, the fishing method presents a risk for both decompression illness and carbon monoxide poisoning, both causes of disabilities and death among small-scale fishers, and with significant negative impacts on the social and economic status of households and coastal communities. Currently, there is a misunderstanding among fishers concerning diving risks. Using a mixed-method analysis, this study reports the risk perceptions of small-scale fishers and hyperbaric personnel about hookah diving, and the actual diving accidents which occur in the spiny lobster and sea cucumber fisheries in the Yucatán northeastern ports. The study highlights the need for appropriate fishing technologies and increased awareness among fishers about the consequences of hookah diving. Fishery managers and health services can make priority decisions based on the information generated. DOI: 10.22462/05.06.2018.7
Introduction: Decompression sickness (DCS) has been associated with unusual circumstances such as breath-hold diving, shallow depths, and short bottom times. We report a case of DCS with an extraordinary cause and course. Materials and Methods: A 72-year-old healthy Hispanic female was referred to our 24/7 Hyperbaric Medicine Unit for emergency hyperbaric oxygen recompression treatment (HBO2 RCT) after developing lower-extremity paralysis following a hyperbaric air exposure in a homemade hyperbaric chamber. Findings/Case report: After an uneventful exposure to hyperbaric air at a maximum 72-foot depth (3.2 ATA, 32.3 psig), the patient had the delayed onset of abdominal pain and paraplegia after eating a meal. After HBO2 RCT in accordance with our management algorithm, the patient had a full recovery. Conclusions: This patient’s presentation and course corresponded to what we label as “disordered decompression” and conformed to our Gradient Perfusion Model. With a finite blood volume and the need to perfuse two “intermediate” tissues simultaneously, we postulate that a “steal” syndrome arose to cause the abdominal and paralysis symptoms. DOI: 10.22462/05.06.2018.6
Introduction: In Part 1 of this three-part series, we provided an explanation as to why and at what sites decompression sickness (DCS) occurs, using the Gradient-Perfusion Model (GPM). In this part, we provide information to substantiate the concept and present clinical cases that were initially labeled as “unexplained DCS,” but later disordering events were identified to explain the clinical presentations. Materials and Methods: Among 500 cases of DCS we have managed for over 50 years, a cohort of these patients was initially diagnosed as unexplained DCS. However, some have shown that disordering events are the likely cause of their DCS. Results: By pairing the tissue involved with the patient’s dive history, a gradient-perfusion imbalance connection was identified. In all serious (Type 2) presentations of DCS, alterations in perfusion of the fast tissues were able to account for the clinical findings. The consequences demonstrated that the gradients overwhelmed the ability of altered perfusion to offgas/offload the inert gas. Pain-only and peripheral neuropathy presentations involved both intermediate and slowly perfused tissues. Rather than perfusion, gradient limitations were the reasons for the clinical presentations of these patients. Conclusions: The GPM accounts for signs and symptom presentations in DCS. This provides the basis for appropriate treatments ..
X.Y. Kuang, L.J. Chen, H.L. Li, F. Yao, J.M. Xu, F. Huang, L.J. Guo
Hakan Ay, Murat Salihoglu, Aytug Altundag, Hakan Tekeli, Ali Memis, Melih Cayonu
Runxiao Lv, Juan Zheng, Zhouheng Ye, Xuejun Sun, Hengyi Tao, Kan Liu, Runping Li, Weigang Xu, Wenwu Liu, Rongjia Zhang