Number 5

[ Letter ] DOI: 10.22462/10.12.2019.24

[ Letter ] DOI: 10.22462/10.12.2019.23

[ Letter ] DOI: 10.22462/10.12.2019.21

[ Editors note ] DOI: 10.22462/10.12.2019.21

[ Letter ] DOI: 10.22462/10.12.2019.20

Introduction: Stingray spine injuries are among the most common marine animal injuries in humans. While most resolve with immersion in warm water, a few become infected and require antibiotics. We present a case report of a presumptive stingray injury that evolved to a major slough and which required prolonged healing in a patient with diabetes mellitus. Our literature review was unable to find a similarly reported case. Materials: A co-author was asked to evaluate and manage an ominous-appearing wound on the right foot of a diabetic. The problem developed after the individual had been wading in shallow ocean beach water. The patient’s diabetic sensory neuropathy obscured the immediate association of the problem with a stingray injury, but this became the presumptive diagnosis when pain developed and necessitated that he seek medical care. Findings/Clinical Course: After an initial urgent care visit, increasing pain and worsening appearance of the patient’s foot necessitated a visit to our emergency department. The patient was admitted the next day due to symptoms of systemic sepsis. On the fourth hospital day, a large bulla on the lateral side of the right foot was excised. This unroofed a full-thickness slough to the periosteum level of the underlying bones. Not ..

A 16-year-old female patient with headache was admitted to our hospital. Radiological examination showed a Spetzler- Martin Grade III arteriovenous malformation (AVM) located at the left frontal lobe. Volume-staged stereotactic radiosurgery (SRS) treatment performed in two fractions at three-month intervals and post-procedural period were uneventful. Eight months later the patient was admitted to our hospital with headache, vomiting, right-sided facial palsy and right upper extremity paresthesia. Radiological examination demonstrated severe vasogenic edema in the left centrum semiovale and temporal region. Due to severe and steroid-resistant malign edema, hyperbaric oxygen (HBO2) therapy was performed as an alternative treatment option. Neurological symptoms resolved completely after HBO2. Radiological examination demonstrated serious improvement of brain edema and mass effect. DOI: 10.22462/10.12.2019.18

We describe the emergency management of a man who experienced acute vision loss diagnosed as direct traumatic optic neuropathy (TON) in his right eye (no light perception) after falling from a height. TON is caused by a high-impact mechanism of injury. Clinical findings include acute vision loss, which is typically immediate, afferent pupillary defect, decreased color vision, and visual field defects. Treatment is controversial because of the lack of strong evidence supporting intervention over observation. In this case report, our treatment strategy comprised immediate hyperbaric oxygen (HBO2) and daily high doses of a steroid. On the second day, minocycline was added to the treatment regimen for its neuroprotective effects. The patient was discharged after receiving six HBO2 treatments and six days of intravenous solumedrol transitioned to oral prednisone. After the third HBO2 treatment, his vision improved to 20/100; after the fourth treatment, it was 20/40 and plateaued. At the time of discharge, it was 20/40. At two-month follow-up, his corrected visual acuity was 20/60+2 in the affected eye. Immediate HBO2 for ischemic and mechanical injury to the optic nerve following trauma is a therapeutic option. DOI: 10.22462/10.12.2019.17

Purpose: To report the successful treatment of postoperative posterior ischemic optic neuropathy (PION) with hyperbaric oxygen therapy and to review the current literature on the pathogenesis and treatment of PION.  Observations: During an angiographic procedure at a community hospital, an elderly woman had a transient drop in blood pressure after receiving an intravenous dose of hydralazine. During recovery, the patient experienced bilateral vision loss. She was transferred to our specialty referral center for treatment with hyperbaric oxygen. We followed Table 5 in the U.S. Navy Diving Manual, the protocol for decompression sickness. Our patient’s vision improved markedly immediately after the first session and continued to improve throughout the course of treatment to its completion. Follow-up ophthalmology visits found the patient’s vision to be close to baseline. Conclusions and importance: PION is a rare condition. It has been difficult to determine a successful therapeutic approach because of the lack of large case-controlled studies. Hyperbaric oxygen has been used to treat other ischemic ophthalmic conditions, but there are only few reports of its use in patients with PION. Systemic steroids and antiplatelet therapy have also been used, with mixed success. In our patient, the combination of hyperbaric oxygen therapy and steroids was successful ..

Successful penile replantations are rarely reported in the literature and are associated with significant complications. We present a case of a patient who auto-amputated his penis. Delayed microvascular replantation was performed approximately 14 hours following injury. He was treated with a phosphodiesterase inhibitor postoperatively, and adjuvant hyperbaric oxygen (HBO2) therapy was started 58 hours after replantation; 20 treatments at 2.4 atmospheres absolute (ATA), twice daily for eight days, followed by once daily for four days. Perfusion of the replanted penis was serially assessed using fluorescent angiography. With some additional surgical procedures including a split- thickness skin graft to the shaft due to skin necrosis he has made a complete recovery with return of normal urinary and sexual function. This unusual case illustrates the potential benefit of HBO2 therapy in preserving viability of a severed body part. Fluorescent angiography may have potential utility in monitoring efficacy of HBO2. DOI: 10.22462/10.12.2019.15

Rationale Decompression sickness (DCS, “bends”) is caused by formation of bubbles in tissues and/or blood when the sum of dissolved gas pressures exceeds ambient pressure (supersaturation) [1]. This may occur when ambient pressure is reduced during any of the following: ascent from a dive; depressurization of a hyperbaric chamber; rapid ascent to altitude in an unpressurised aircraft or hypobaric chamber; loss of cabin pressure in an aircraft [2] and during space walks. DOI: 10.22462/10.12.2019.14

Gas can enter arteries (arterial gas embolism, AGE) due to alveolar-capillary disruption (caused by pulmonary over-pressurization, e.g. breath-hold ascent by divers) or veins (venous gas embolism, VGE) as a result of tissue bubble formation due to decompression (diving, altitude exposure) or during certain surgical procedures where capillary hydrostatic pressure at the incision site is subatmospheric. Both AGE and VGE can be caused by iatrogenic gas injection. AGE usually produces stroke-like manifestations, such as impaired consciousness, confusion, seizures and focal neurological deficits. Small amounts of VGE are often tolerated due to filtration by pulmonary capillaries; however VGE can cause pulmonary edema, cardiac “vapor lock” and AGE due to transpulmonary passage or right-to-left shunt through a patient foramen ovale. Intravascular gas can cause arterial obstruction or endothelial damage and secondary vasospasm and capillary leak. Vascular gas is frequently not visible with radiographic imaging, which should not be used to exclude the diagnosis of AGE. Isolated VGE usually requires no treatment; AGE treatment is similar to decompression sickness (DCS), with first aid oxygen then hyperbaric oxygen. Although cerebral AGE (CAGE) often causes intracranial hypertension, animal studies have failed to demonstrate a benefit of induced hypocapnia. An evidence-based review of adjunctive therapies is ..

We compared the efficacy of hyperbaric oxygen (HBO2) therapy used in the treatment of sudden sensorineural hearing loss (SSNHL) as a supplementary therapy to the first-line medical treatment according to the different applied pressures used in HBO2 treatment while maintaining the same number of sessions, periodicity and exposure times. We evaluated data from 115 patients suffering from SSNHL within seven days of hearing loss: 35 patients received the standard treatment protocol (control group), and 80 individuals were treated with additional application of HBO2 therapy pressured to 2.0 ATA (H2.0; n=49) or 2.5 ATA (H2.5; n=31), respectively. Treatment success was assessed using pre- and post-treatment audiograms. We found significant differences in both HBO2 groups compared to the control group. In low frequencies the most significant differences can be seen in both H2.0 and H2.5. In spoken speech frequencies only the H2.0 group was statistically significant. In high frequencies the therapeutic benefits were the lowest. Furthermore, we found a notable difference in the therapeutic effect of HBO2 therapy according to the different applied pressure. At low frequencies, the use of 2.5 ATA pressure was more efficient. However, in the higher frequency ranges, the better hearing gains were obtained at the 2.0 ..

Treatment of idiopathic sensorineural hearing loss (ISSNHL) is problematic due to the unclear etiology of the illness. Corticosteroid is recommended by some papers, and hyperbaric oxygen (HBO2) by others. Recently HBO2 has been shown to be an important therapy for ISSNHL, with an increasing number of studies demonstrating its beneficial results. Recovery from ISSNHL depends on the interval period between onset and treatment, hearing loss severity and audiogram type used to determine damage. Treatment of ISSNHL requires a detailed analysis. In this retrospective study we reviewed data from 56 patients with moderate ISSNHL. These patients were divided into three groups based on different treatments: corticosteroid group; corticosteroid + HBO2 (combination)group; and HBO2-only group. Additionally, all patients received intravenous vasodilator treatment. Hearing levels before and after treatment were compared. All three groups had a similar recovery rate, with an effective rate of more than 50%, and a hearing gain average of 17.38 decibels (dB). HBO2 treatment got a higher recovery rate. The combination therapy, which included corticosteroid and HBO2, did not elevate the recovery rate. DOI: 10.22462/10.12.2019.11

Background: Carboxyhemoglobin (COHb) levels are obtained when there is suspicion for carbon monoxide (CO) exposure. Serial COHb levels are sometimes obtained despite the well-established half-life of COHb with oxygen supplementation. We sought to evaluate the trends and characteristics associated with obtaining serial carboxyhemoglobin levels. Methods: A retrospective review was performed at an academic medical center for all inpatient and emergency department cases with either single COHb or serial COHb levels from 1 April 2010 through 31 March 2015. Data collected included age, gender, pregnancy status, smoking history, encounter month, admission status, oxygen administration, fire or burn history, vital signs, presenting symptoms, hyperbaric oxygen (HBO2) therapy use, initial pH, troponin, lactate, and COHb levels. The time and change in values between serial levels were also obtained. Results: 624 cases were identified, with 106 (17%) having multiple carboxyhemoglobin levels. A mean of 2.6 (range 2 - 9) serial COHb levels were obtained. The average initial COHb was 8.9%. Subsequent serial levels were obtained on average at 353, 663 and 1,095 minutes and averaged 2.8%, 1.8% and 1.1% respectively. Serial COHb levels were obtained more commonly in burn patients, those admitted to the ICU and those who had HBO2 therapy. Four patients had an ..

Introduction: The effects of hyperbaric oxygen (HBO2) therapy on sprains, ligament injuries, and muscle strains have been reported in several animal studies. In a dog model of compartment syndrome and in a rat contused skeletal muscle injury model, the significant effects of HBO2 therapy on the reduction of edema and muscle necrosis have been reported. In basic research HBO2 therapy stimulated fibroblast activity to improve the healing process. Because of this it expected that HBO2 therapy might improve focal edema and pain in the acute phase and accelerate the healing of injured tissues in athletes with a medial collateral ligament (MCL) injury of the knee. This study aimed to examine the short-term effects of HBO2 application subjectively, and the long-term effects of HBO2 therapy in Japanese professional or semi-professional rugby players with grade 2 MCL injury of the knee. Methods: Thirty-two professional or semi-professional rugby players with grade 2 MCL injury of the knee were investigated. First, in the HBO2 group (n=16), HBO2 therapy was performed during the acute phase. Visual analog scales (VASs) immediately before and after HBO2 therapy on the same day were compared. Next, we retrospectively evaluated the time to return to play in the HBO2 (n=16) ..

We aimed to assess the effects of intermittent hyperbaric oxygenation (HBO2 at 2 bars for 120 minutes a day for four successive days) on acetylcholine-induced vasorelaxation (AChIR) in female Sprague-Dawley (SD) rats (N=80) that were randomized into four groups: healthy controls (CTR); diabetic rats (DM); and control and diabetic rats that underwent hyperbaric oxygenation (CTR+HBO and DM+HBO), respectively. AChIR was measured in vitro in aortic rings, with/without L-NAME, MS-PPOH, HET0016 or indomethacin. mRNA expression of eNOS, iNOS, COX-1, COX-2, thromboxane A synthase 1 (TBXAS1), CYP4A1, CYP4A3 and CYP2J3 was assessed by qPCR. Systemic oxidative stress and plasma antioxidative capacity were determined with the thiobarbituric acid-reactive substances (TBARS) and the ferric reducing ability of plasma (FRAP) assays, respectively. There was no significant difference in AChIR among experimental groups of rats. In CTR and DM group of rats, AChIR was mediated by NO and EETs pathway, while in the CTR+HBO and DM+HBO groups, NO-pathway prevailed. iNOS expression was upregulated in the DM group compared to CTR, while HBO2 upregulated eNOS in CTR group and TBXAS1 in DM group of rats. In both, CTR and DM group of rats, the sensitivity to ACh in the presence of L-NAME or in the presence ..

A 54-year-old man suffered a leg cramp while diving in the ocean at a depth of 20 meters. He began to surface, with his ascent based on a decompression table. He lost consciousness at the surface and was rescued by a nearby boat. The boat staff judged him to be in cardiac arrest, so they performed chest compressions. When the boat reached port where an ambulance was waiting, emergency medical technicians confirmed that the patient was in cardiac arrest; his initial rhythm was asystole. Treated with basic life support, the patient was then transported to a rendezvous point, where a physician-staffed helicopter waited. The patient remained in cardiac arrest, so the staff of the helicopter performed tracheal intubation with mechanical ventilation, securing a venous route, infusion of adrenaline, and mechanical chest compression. On arrival at our hospital 100 minutes after collapse, he remained in cardiac arrest. Continued advanced cardiac life support failed to obtain spontaneous circulation. Whole-body computed tomography (CT) at 120 minutes after the collapse showed multiple gas bubbles in the heart, aorta, inferior vena cava, cerebral artery, coronary artery and portal vein with lung edema. This is the first case to show gas in the bilateral coronary ..

Objective: To evaluate the efficiency of percutaneous patent foramen ovale (PFO) closure on the recurrence of decompression illness (DCI). Design: Retrospective, observational study with interview and questionnaire Setting: Tertiary referral center. Population: 59 scuba divers with a history of DCI who received a percutaneous PFO closure. Main outcome measurements: Questionnaire about health status, dive habits and recurrence of DCI after PFO closure. Results: A total of 59 divers with DCI were included. The most common manifestations of DCI were cutaneous or vestibular DCI. Procedural complications occurred in four patients but none with long-term consequences. Four patients had recurrence of DCI after closure during a 10-year follow-up. In three of these cases there was residual shunting, all of which were initially considered closed. The fourth patient had aggravating factors for his recurrent DCI. A quarter of the patients stated to have changed their diving habits. Four patients quit diving. Conclusion: Percutaneous PFO closure for secondary prevention of DCI is associated with few, but not negligible, complications. As a large portion of our cohort changed their diving habit after closure it is difficult to ascertain the efficiency of PFO closure for secondary prevention of DCI. However, the study shows that PFO closure does not fully protect against ..

Objective: Scuba diving and freediving are popular activities around the world, and their growth has increased the frequency of related pathology. A good ability to equalize is of paramount importance for diving. This is especially true for freediving, during which dive time is limited to just one breath. Even though equalization disorders are quite common in divers, a scoring system does not exist to date. In this paper we propose a new scoring system for equalization problems of freedivers: the EP score – shorthand for “equalization problems.” Methods: We administered the EP score assessment to 40 Italian freediving spearfishermen who were divided in two groups: Group A comprised 20 freedivers complaining of equalization problems and multiple barotraumas but totally asymptomatic in their everyday lives. These individuals had already received medical treatment and nasal surgery without improvement and then had undergone Eustachian tube balloon dilation. Group B comprised 20 healthy freedivers without any history of equalization disorders. We performed a statistical analysis to evaluate the reliability of this scoring system and to evaluate its usefulness in diagnosis and follow-up. Results: Our data show substantial statistical differences between healthy freedivers and freedivers complaining of equalization disorders (Z-Score = -5.396 at p < 0.05); ..

Background: Immersion can cause immersion pulmonary edema (IPE) in previously healthy subjects. We performed a case-control study to better identify IPE risk factors.  Methods: We prospectively included recreational scuba divers who had presented signs of IPE and control divers who were randomly chosen among diving members of the French Underwater Federation. We sent an anonymous questionnaire to each diver, with questions on individual characteristics, as well as the conditions of the most recent dive (controls) or the dive during which IPE occurred. Univariate logistic regressions were performed for each relevant factor. Then, multivariate logistic regression was performed. Results: Of the 882 questionnaires sent, 480 (54%) were returned from 88 cases (90%) and 392 control divers (50%). Multivariate analysis identified the following independent risk factors associated with IPE: being aged over 50 years ((OR) 3.30, (95%CI) 1.76-6.19); female sex (OR 2.20, 95%CI 1.19-4.08); non-steroidal anti-inflammatory drug (NSAID) intake before diving (OR 24.32, 95%CI 2.86-206.91); depth of dive over 20 m (OR 2.00, 95%CI 1.07-3.74); physical exertion prior to or during the dive (OR 5.51, 95%CI 2.69-11.28); training dive type (OR 5.34, 95%CI 2.62-10.86); and daily medication intake (OR 2.79, 95%CI 1.50-5.21); this latter factor appeared to be associated with hypertension in the univariate analysis. Conclusions: To reduce the risk of ..

Aim: To review incidents of immersion pulmonary edema (IPE) from Oceania, to determine the demographics, diving parameters, and comorbidities that may be related to this disorder. Method: Incidents of IPE, most of which were documented by Divers Alert Network Asia-Pacific (DAN AP) or reported in our medical literature, were analyzed. They included interviews with the survivors and a review of available medical records. Only incidents diagnosed as IPE by specialist diving physicians or pathologists with experience in the investigation of diving accidents were included. Results: Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers, which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 msw for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities in this cohort. Medical comorbidities were recorded in 68%, with 42% being cardiac. The latter included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%. Conclusion: IPE was more likely in middle-aged females, in experienced divers, and during ascent or after surfacing. Commonly reported ..

Introduction: We aimed to document identified cases of immersion pulmonary edema (IPE) in divers from Oceania (the Indo-Pacific region) from January 2002 to May 2018, inclusive. Method: Cases were identified using various sources, including searches of the Divers Alert Network Asia-Pacific (DAN AP) Fatality Database, published case reports, and interviews with survivors who had reported their incident to DAN AP. Where available, investigations, pathology and autopsy results were obtained. Only incidents diagnosed as IPE by diving physicians or pathologists with experience in the investigation of diving accidents were included. Individual case histories and outcomes, together with brief individual summaries of the associations and possible contributing factors were recorded. Results: Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 meters of seawater for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities. Cardiac anomalies dominated the associated or possible contributing factors. These included valvular disease in 29%, transient cardiomyopathies in 26% and ..

Immersion pulmonary (IPE, also known as swimming-induced pulmonary edema, SIPE) is a condition in which pulmonary edema develops rapidly during a dive or vigorous swim. Symptoms include dyspnea and hemoptysis. Physical exam reveals typical signs of bilateral pulmonary edema, which can be confirmed radiographically or with bedside ultrasound [1-3]. IPE tends to recur in susceptible individuals. Often there are cardiac or pulmonary comorbidities, but IPE can occur in highly fit individuals such as triathletes and military trainees: IPE has been reported among special forces units from both the United States and Israel. Why pulmonary edema, a condition typically associated with heart failure, should occur in normal individuals remains somewhat of a mystery. DOI: 10.22462/10.12.2019.1