Immersion Ultrasound Therapy in Combination with Manual Therapy in the Treatment of Ischemic Digital Ulcers in Systemic Sclerosis.

Background and Objectives: Digital ulcers (DUs) are the most common complication in patients with Systemic Sclerosis (SSc). They cause pain with hand dysfunction and negatively impact activities of daily and working life. Our study aims to evaluate the efficacy of a combined treatment of manual therapy and ultrasound therapy in SSc patients with ischemic DU (IDU) compared to manual therapy alone. Materials and Methods: We conducted a before-and-after study (non-randomized study). We enrolled a consecutive series of IDU patients undergoing rehabilitation treatment and divided them into two groups: a treatment group consisting of patients undergoing a combination of manual therapy and US water immersion and a standard care group consisting of patients subjected to manual therapy alone. At the time of the first visit (T0) and at the end of the 4-week rehabilitation period (T1), we evaluated functional capacity, pain intensity, ulcer evolution, and quality of life. Results: In the treatment group, we observed a statistically significant improvement in the functional capacity of the hand (DHI: 28.15 ± 11.0 vs. 19.05 ± 8.83; p < 0.05), pain (NRS: 5.55 ± 1.2 vs. 2.9 ± 1.09; p < 0.05), and PSST score (24.4 ± 4.0 vs. 16.2 ± 2.36; p < 0.05). In the standard care group, we observed a statistically significant improvement only for the functional capacity of the hand (DHI: 28.85 ± 9.72 vs. 22.7 ± 7.68; p < 0.05). Finally, from the comparison between the treatment group and the standard care group, we observed statistically significant improvements in pain (2.9 ± 1.09 vs. 4.5 ± 1.07; p < 0.05) and in the PSST scale (16.2 ± 2.36 vs. 20.4 ± 4.02; p < 0.05). Furthermore, at the end of treatment in the treatment group, 15 ulcers (62.5%) were completely healed, while in the standard care group, only 3 ulcers were completely healed (14.3%). Conclusions: Combined treatment with manual therapy and ultrasound therapy appears to be useful in the management of IDU in patients with scleroderma.

Thermal response of human body with immersion suit in cold environment.

Hypothermia caused by cold water immersion is one of the main causes of death in marine accidents. Immersion suit is a kind of protective clothing when implementing flying tasks over the sea in cold seasons, with the main function to slow down the loss of human heat in water and prolong the survival time. In this study, the thermal properties and wearing types of immersion suit and underwear were analyzed. The subjects with internal- and external-wear immersion suit exposed to the experimental environments for 2 h in five working conditions. The core temperature, weighted average skin temperature, and average body temperature were measured and calculated. Both internal- and external-wear immersion suits could fulfil the cold protection requirements under the experimental conditions. The results of clothing parameter tests and physiological experiments both exhibit that the external-wear immersion suit has better thermal insulation effect. And the tolerance time in low-temperature water was predicted, which is crucial for effective and efficient rescue during shipwreck in adverse thermal scenarios. In future research, a comprehensive evaluation and analysis of the thermal insulation performance of immersion suit could be completed in combination with the water ingress of the clothing, the subjects' thermal comfort, and flexibility of the clothing.

The effect of various breath-hold techniques on the cardiorespiratory response to facial immersion in humans.

NEW FINDINGS: What is the central question of this study? What is the effect of three repeated breath-hold techniques routinely used by freedivers, thought to manipulate arterial partial pressures of O2 and CO2 , on the cardiorespiratory and haematological response to breath-holding during facial immersion? What is the main finding and its importance? All three techniques increased breath-hold by a similar duration, probably owing to the similar marked increase in end-tidal O2 and decrease in end-tidal CO2 observed in all three trials before facial immersion. These were the only cardiorespiratory changes that were consistently manipulated before the maximal breath-hold. This would suggest that pronounced bradycardia and vasoconstriction of selective vascular beds are probably not obligatory for prolonging breath-hold duration. ABSTRACT: Repeated maximal breath-holds have been demonstrated to induce bradycardia, increase haematocrit and haemoglobin and prolong subsequent breath-hold duration by 20%. Freedivers use non-maximal breath-hold techniques (BHTs) to improve breath-hold duration. The aim of this study was to investigate the cardiorespiratory and haematological responses to various BHTs. Ten healthy men (34.5 ± 1.9 years) attended five randomized experimental trials and performed a 40 min period of quiet rest or one of three BHTs followed by a maximal breath-hold challenge during facial immersion in water at 30 or 10°C. Cardiovascular and respiratory parameters were measured continuously using finger plethysmography and breath-by-breath gas analysis, respectively, and venous blood samples were collected throughout. Facial immersion in cold water caused marked bradycardia (74.1 vs. 50.2 beats/min after 40 s) but did not increase breath-hold duration compared with warm water control conditions. Facial immersion breath-hold duration was 30.8-43.3% greater than the control duration when preceded by BHTs that involved repeated breath-holds of constant duration (P = 0.021), increasing duration (P < 0.001) or increasing frequency (P < 0.001), with no difference observed between BHTs. The increased duration of apnoea across all three BHT protocols was associated with a 6.8% increase in end-tidal O2 and a 13.1% decrease in end-tidal CO2 immediately before facial immersion. There were no differences in blood pressure, cardiac output, heart rate, haematocrit or haemoglobin between each BHT and control conditions (P > 0.05). In conclusion, the duration of apnoea can be extended by manipulating blood gases through repeated prior breath-holds, but changes in cardiac output and red blood cell mass do not appear essential.

Virtual reality immersion compared to monitored anesthesia care for hand surgery: A randomized controlled trial.

INTRODUCTION: Common anesthesia practice for hand surgery combines a preoperative regional anesthetic and intraoperative monitored anesthesia care (MAC). Despite adequate regional anesthesia, patients may receive doses of intraoperative sedatives which can result in oversedation and potentially avoidable complications. VR could prove to be a valuable tool for patients and providers by distracting the mind from processing noxious stimuli resulting in minimized sedative use and reduced risk of oversedation without negatively impacting patient satisfaction. Our hypothesis was that intraoperative VR use reduces sedative dosing during elective hand surgery without detracting from patient satisfaction as compared to a usual care control. METHODS: Forty adults undergoing hand surgery were randomized to receive either intraoperative VR in addition to MAC, or usual MAC. Patients in both groups received preoperative regional anesthesia at provider discretion. Intraoperatively, the VR group viewed programming of their choice via a head-mounted display. The primary outcome was intraoperative propofol dose per hour (mg · hr-1). Secondary outcomes included patient reported pain and anxiety, overall satisfaction, functional outcome, and post anesthesia care unit (PACU) length of stay (LOS). RESULTS: Of the 40 enrolled patients, 34 completed the perioperative portion of the trial. VR group patients received significantly less propofol per hour than the control group (Mean (±SD): 125.3 (±296.0) vs 750.6 (±334.6) mg · hr-1, p<0.001). There were no significant differences between groups in patient reported overall satisfaction, (0-100 scale, Median (IQR) 92 (77-100) vs 100 (100-100), VR vs control, p = 0.087). There were no significant differences between groups in PACU pain scores, perioperative opioid analgesic dose, or in postoperative functional outcome. PACU LOS was significantly decreased in the VR group (53.0 (43.0-72.0) vs 75.0 (57.5-89.0) min, p = 0.018). CONCLUSION: VR immersion during hand surgery led to significant reductions in intraoperative propofol dose and PACU LOS without negatively impacting key patient reported outcomes.

Immersion-Induced Mitral Regurgitation: A Novel Risk Factor for Swimming-Induced Pulmonary Edema.

Immersion pulmonary edema, more commonly referred to as swimming-induced pulmonary edema (SIPE), is a well-documented condition believed to be a result of immersion physiologic condition that is characterized by a peripheral-to-central redistribution of blood volume. It disproportionally affects young, healthy athletes with no clinically overt cardiovascular or pulmonary conditions. We present four cases of healthy athletes with previously documented SIPE, who participated in Institutional Review Board-approved clinical studies that examined the pathophysiologic condition and prevention of SIPE. During standard recumbent echocardiography, trivial mitral regurgitation was observed in all four individuals. Acute exacerbation of their mitral regurgitation was observed during immersion with both immersed resting and immersed exercise echocardiography, contributing to the development of SIPE. These observations demonstrate that the occurrence of subclinical or trivial mitral valve regurgitation during dry rest is a novel risk factor for SIPE. We propose the use of immersion echocardiography as a useful investigative tool for otherwise healthy individuals with SIPE and no previously explainable cause.

Water immersion skin wrinkling: modulation by common participant characteristics.

BACKGROUND: Water immersion skin wrinkling (WISW) has been used as a noninvasive test of a limb's sympathetic function. To date, research has not sufficiently explored this phenomenon. The primary aim of this study was to determine the impact of common individual characteristics on WISW. METHODS: Demographic information was collected on 39 apparently healthy adults varying widely in age. Each participant submerged one hand in 40°C water for 30 minutes. The degree of WISW was assessed using computer software. Because WISW is often associated with peripheral edema and facial wrinkling, we also evaluated facial wrinkling and hand volume expansion following prolonged immersion. RESULTS: Sex, body mass index, and physical activity habits were not correlated with any of the WISW measures. Age was a predictor of the WISW score (ß = -0.38, P = 0.02, R2 = 0.15). WISW score was significantly lower for participants who reported relevant medical history (cardiovascular, pulmonary, or psychological) than those with no such report. WISW was not associated with face wrinkling or hand volume expansion. CONCLUSION: We concluded that WISW was reduced in older age and those with medical history but was not affected by physical activity. These results are consistent with the prevalent notion that WISW may be a sympathetically mediated phenomenon.

Fatal diving: could it be an immersion pulmonary edema? Case report.

Immersion pulmonary edema is a rare, underrecognized, and potentially lethal pathology developing during scuba diving and other immersion-related activities (swimming or apnoea). Physiopathology is complex and not fully understood, but its mechanisms involve an alteration of the alveolo-capillary barrier caused by transcapillary pressure elevation during immersion, leading to an accumulation of fluid and blood in the alveolar space. Diagnosis remains a challenge for clinicians and forensic practionner. The symptoms begin during ascent, with cough, frothy sputum, and hemoptysis. Auscultation reveals signs of pulmonary edema. Pulmonary CT scan, which is the radiological exam of choice, shows ground glass opacities and interlobular thickening, eventually demonstrating a patterned distribution, likely in the anterior segments of both lungs. Apart from the support of vital functions, there is no specific treatment and hyperbaric oxygen therapy is not systematically recommended. We present a case of fatal IPE occurring in a recreational diver who unfortunately died shortly after his last dive. Diagnosis was made after complete forensic investigations including post-mortem-computed tomography, complete forensic autopsy, histological examination, and toxicological analysis.

The Antibiotic Immersion of Custom-Made Porous Hydroxyapatite Cranioplasty: A Multicentric Cohort Study.

ABSTRACT: Cranioplasty is a common neurosurgical procedure performed to reconstruct cranial defects. The most common cranioplasty materials used today can be divided into 2 types: autologous bone and bone substitutes, such as polyetheretherketone, titanium mesh, poly-methyl methacrylate, and Hydroxyapatite (HA). Infection represents one of the most feared complications, ranging from 2.3% to 20%. Early implant infections occur within 30 days from the operation and are mostly due to pathogens from the skin and the paranasal cavity. The authors aim to demonstrate the efficacy of our preoperative antibiotic immersion protocol of custom-made HA prosthesis, to prevent early implant infections. The authors compare this population to cranioplasties without preoperative antibiotic elution and those with anonstandardized antibiotic elution. The authors retrospectively analyzed data from patients referred to 6 different hospitals in northern Italy, in the period 2000 to 2020. Inclusion criteria were patients requiring reconstruction of thecal bone with HA prosthesis after post-traumatic decompressive surgery; age more than 18 years; detailed patient history and clinical data; and follow-up of minimum 6 months. A total of 77 cranioplasties were included in the study, along with 120 retrospective cases in comparison. Infections occurred in 2.6% of cranioplasties with antibiotic immersion compared to 7.8% of cranioplasties without. Even if nonsignificant, these results support our hypothesis that pretreatment of HA implants with antibiotic appears to prevent cranioplasty infections and could be a viable option to improve cranioplasty outcomes in the future.

Enhancement of the RhoA/Rho kinase pathway is associated with stress-related erectile dysfunction in a restraint water immersion stress model.

Stress is a risk factor for erectile dysfunction (ED); however, the pathology of stress-induced ED remains unclear. Accordingly, in this study, we investigated the mechanisms of stress-induced ED using a rat model. Ten-week-old male Wistar/ST rats were maintained in a cage filled with water to a height of 2 cm (stress group) or a normal cage (control group). We found that water immersion stress significantly enhanced the contractile response to noradrenaline in the corpus cavernosum (CC) (p < 0.05). Moreover, stress significantly decreased erectile function, as assessed by changes in intracavernous pressure (p < 0.01). In addition, Rho kinase-1 (ROCK-1) protein expression was significantly upregulated under stress conditions (p < 0.05), and phosphorylated myosin light chain (phospho-MLC) levels, contribute to smooth muscle contraction, were also upregulated (p < 0.01). Treatment with fasudil hydrochloride, a Rho kinase inhibitor, for 5 days significantly improved erectile function (p < 0.01) and normalized ROCK-1 and phospho-MLC levels (p < 0.01). Thus, the RhoA/Rho kinase pathway may be associated with stress-induced ED via contraction of CC. Stress also decreased the smooth muscle/collagen ratio of CC (p < 0.01), and fasudil treatment did not alleviate these effects (p = 0.50). These findings suggested that penile fibrosis gradually progressed under stress conditions and that fibrosis may be independent of the RhoA/Rho kinase pathway, implying that longer exposure to stress may promote ED. We conclude that stress-induced ED was caused by contraction of CC mediated by the RhoA/Rho kinase pathway.

Land-traffic crash leading to passenger vehicle submersion, drowning and other fatal injuries: A 44-year study based on records from the Finnish Crash Data Institute.

BACKGROUND: Land motor traffic crash (LMTC) -related drownings are an overlooked and preventable cause of injury death. The aim of this study was to analyze the profile of water-related LMTCs involving passenger cars and leading to drowning and fatal injuries in Finland, 1972 through 2015. MATERIALS AND METHODS: The database of the Finnish Crash Data Institute (FCDI) that gathers detailed information on fatal traffic accidents provided records on all LMTCs leading to drowning during the study period and, from 2002 to 2015, on all water-related LMTCs, regardless of the cause of death. For each crash, we considered variables on circumstances, vehicle, and fatality profiles. RESULTS: During the study period, the FCDI investigated 225 water-related LMTCs resulting in 285 fatalities. The majority of crashes involved passenger cars (124), and the cause of death was mostly drowning (167). Only 61 (36.5%) fatalities suffered some-generally mild-injuries. The crashes frequently occurred during fall or summer (63.7%), in a river or ditch (60.5%), and resulted in complete vehicle's submersion (53.7 %). Half of the crashes occurred in adverse weather conditions and in over 40% of the cases, the driver had exceeded the speed limit. Among drivers, 77 (68.8%) tested positive for alcohol (mean BAC 1.8%). CONCLUSION: Multidisciplinary investigations of LMTCs have a much higher potential than do exclusive police and medico-legal investigations. The risk factors of water-related LMTCs are similar to those of other traffic crashes. However, generally the fatal event in water-related LMTC is not the crash itself, but drowning. The paucity of severe physical injuries suggests that victims' functional capacity is usually preserved during vehicle submersion. Practical Applications: In water-related LMTCs, expansion of safety measures is warranted from general traffic-injury prevention to prevention of drowning, including development of safety features for submerged vehicles and simple self-rescue protocols to escape from a sinking vehicle.

BMSC seeding in different scaffold incorporation with hyperbaric oxygen treats seawater-immersed bony defect.

INTRODUCTION: The experiment was undertaken to estimate the effect of BMSC seeding in different scaffold incorporation with HBO on the repair of a seawater-immersed bone defect. And future compared n-HA/PLGA with ß-TCP/PLGA as a scaffold in treatment effect of the seawater-immersed bone defect. METHODS: Sixty New Zealand White rabbits with standard seawater defect in radius were randomly divided into group A (implant with nothing), group B (implanted with autogenous bone), group C (implanted with n-HA/PLGA/BMSCs), and group D (implanted with ß-TCP/PLGA/BMSCs). After the implant, each rabbit receives HBO treatment at 2.4 ATA 100% oxygen for 120 min/day for 2 weeks. Radiograph, histological, and biomechanical examinations were used to analyze osteogenesis. RESULT: X-ray analysis shows that n-HA/PLGA/BMSCs and ß-TCP/PLGA/BMSCs could accelerate the new bone formation, and the new bone formation in group C was larger than that in group D or group A and close to group B (P < 0.05). After 12 weeks, in group A, the defect without scaffold shows a loose connect tissue filled in the areas. The medullary canal in group B was recanalized. Defects in groups C and D show a larger number of woven bone formation. The new woven bone formation in defect areas in group C was larger than that in group D. The mechanical examination revealed ultimate strength at 12 weeks was group D > group C > group B > group A (P < 0.05). CONCLUSION: Scaffolds of n-HA/PLGA and ß-TCP/PLGA incorporation with HBO and BMSCs were effective to treat seawater-immersed bone defect, and n-HA/PLGA was more excellent than ß-TCP/PLGA.

Prolonged Brackish Water Exposure: A Case Report.

Exposure to and consumption of brackish water are associated with an elevated risk of infection, hypernatremia, and hypothermia. Minimal data exist to support the diagnosis and treatment of patients with long-term brackish water exposure. We present a case of a patient who spent 5 to 10 d semisubmerged in the Elizabeth River in coastal Virginia. A 55-y-old male presented via ambulance after 5 to 10 d of being "stuck in the mud." He was hypernatremic, with a sodium of 176 mEq·L-1, hypothermic to 34.5°C (94.1°F), and hypotensive at 88/50 mm Hg, with a sodium concentration of 176 mEq·L-1 and an osmolality of 412 mosm·kg-1. He developed pneumonia, with respiratory cultures growing Vibrio parahemolyticus, Klebsiella oxytoca, and Shewanella algae. He had pustules, which grew Aeromonas hydrophilia and Aeromonas caviae. A nasogastric tube was placed. Using suction, 500 mL of coarse sand and gravel was removed from his stomach. Antibiotics and intravenous fluids were given. The patient fully recovered after 3 wk and was discharged to rehabilitation. Exposure to brackish water can present a unique set of infectious and metabolic complications. Initial care should include treatment of metabolic derangements, such as hypovolemia, hypernatremia, and hypothermia, and treatment of infections with antibiotics based on knowledge of the most likely causative organisms.

Whole-body active heating does not preserve finger temperature or manual dexterity during cold-water immersion.

Background: Cold-water immersion impairs manual dexterity when finger temperature is below 15°C. This exposes divers to increased risk of error. We hypothesized that whole-body active heating would maintain finger temperatures and dexterity during cold-water immersion. Methods: Twelve subjects (six males) (22 ± 2 years old; BMI 23.9 ± 2.5; body fat 16 ± 6%) completed 60-minute head-out water immersion (HOWI) wearing a 7mm wetsuit and 3mm gloves in thermoneutral water (TN 25°C) and cold water (CW 10°C) while wearing a water-perfused suit (WP) with 37°C water circulated over the torso, arms, and legs. Gross (Minnesota Manual Dexterity Test [MMDT]) and fine (modified Purdue Pegboard [PPT]) dexterity were assessed before, during and after immersion. Core body and skin temperatures were recorded every 10 minutes. Results: MMDT (TN -25 ± 14%; CW -72 ± 23%; WP -67 ± 29%; p<0.05) and PPT (TN -16 ± 9%; CW: -45 ± 10%; WP: -38 ± 13%; p<0.05) performance decreased during immersion. MMDT and PPT did not differ between CW and WP. Immediately following immersion gross dexterity was recovered in all conditions. Post-immersion fine dexterity was still impaired in CW (p<0.01), but not WP or TN. Core and skin temperatures decreased during immersion in CW and WP (p<0.05) but did not differ between CW and WP. Conclusion: Manual dexterity decreased during immersion. Dexterity was further impaired during cold-water immersion and was not maintained by water perfusion active heating. Warm water perfusion did not maintain finger temperature above 15°C but hand temperature remained above these limits, suggesting a need to reassess thermal thresholds for working divers in cold-water conditions.

DUOX2, a common modulator in preventive effects of monoamine-based antidepressants on water immersion restraint stress- and indomethacin- induced gastric mucosal damage.

Multiple kinds of monoamine-based antidepressants have been shown prophylactic effects in experimentally induced gastric ulcer. The loss of redox homeostasis plays a principle role in the development of peptic mucosal damage. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases are one of the most important sources of reactive oxygen species within the gastrointestinal tract. It is unclear whether there are some common NADPH oxidases modulated by monoamine-based antidepressants in different gastric mucosal damage models. We explored the effects of selective serotonin-norepinephrine reuptake inhibitor (SNRI) duloxetine on the reactive oxygen species production and antioxidant capacity in the gastric mucosa of water immersion restraint (WIRS) or indomethacin treated rats, and examined the role of NADPH oxidases in the protective effects. Pretreated duloxetine prevented the increase of gastric mucosal NADPH oxidase activity and NADPH oxidase inhibitor apocynin dose-dependently protected gastric mucosa from damage by the two factors. Furthermore, dual oxidase 2 (DUOX2) and NADPH oxidase4 (NOX4) are involved in the protective effects of duloxetine in both models. We then examined NADPH oxidases expression modulated by the other monoamine-based antidepressants including selective serotonin reuptake inhibitor (SSRIs) fluoxetine, tricyclic agent (TCAs) amitriptyline and monoamine oxidase inhibitor (MAOs) moclobemide in the two models, and all the three antidepressants reduced the DUOX2 expression in the gastric mucosa. So DUOX2 was a common modulator in the preventive effects of all the monoamine-based antidepressants on WIRS- and indomethacin-induced gastric lesion. Our work provided a peripheral joint molecular target for monoamine modulatory antidepressants, which may be helpful to reveal the mechanisms of this kind of drugs more than monoamine regulation.

Iatrogenic Thermal Burns Secondary to Marine Sting Treatment.

Hot water immersion (HWI) therapy is an effective and validated treatment for a variety of marine stings. Unsupervised, however, it poses a significant risk of thermal injury. Herein, we describe our experience of iatrogenic thermal injury secondary to marine sting treatment. A 5-year retrospective review of all iatrogenic thermal burns secondary to marine stings referred to the State Adult Burn Service was conducted. Nine patients were identified, all sustaining stings to the feet from estuarine cobblerfish, stonefish, and stingrays. All patients continued unsupervised HWI at home and sustained thermal injury to their feet. The majority were treated conservatively with dressings and elevation. One patient required surgical debridement. While heat application is an effective treatment for marine stings, further patient education is required following discharge from point of care. We recommend that first-aid treatment guidelines be updated to reflect that patients are not recommended to continue scalding water immersion at home. However, if patients wish to continue HWI, water temperature should be checked manually with a thermometer or with a nonstung limb and limited to 30 minutes immersion, with 30-minute skin recovery time between.

Water Immersion During the Labour and Effects on Oxidative Stress.

Objective: The study aims to investigate maternal serum thiol/disulfide homeostasis and ischemia-modified albumin (IMA) levels of women who were submerged during labor. Material and methods: Sixty-four pregnant women were enrolled in this study. Thirty-four women were submerged during the first stage of labor and 30 women were not. Native thiol, total thiol, disulfide, albumin, IMA, disulfide/native thiol, disulfide/total thiol and native thiol/total thiol concentrations were measured and demographic data were obtained. Results: Cord blood pH, serum disulfide levels and (disulfide/total thiol) × 100 levels were significantly lower in the water immersion group (P < 0.01, P = 0.01 and P < 0.01, respectively). Native thiol, total thiol, albumin and IMA levels were higher in the water immersion group P < 0.01, P < 0.01, P = 0.001 and P < 0.01, respectively). Conclusion: Water immersion during the first stage of labor was found to be associated with deterioration of thiol-disulfide homeostasis with respect to antioxidant status while IMA levels were higher, suggesting an ischemic condition.

Seawater Immersion Aggravates Early Mitochondrial Dysfunction and Increases Neuronal Apoptosis After Traumatic Brain Injury.

Traumatic brain injury (TBI) is a major cause of death and disability in naval warfare. Due to the unique physiochemical properties of seawater, immersion in it exacerbates TBI and induces severe neural damage and complications. However, the characteristics and underlying mechanisms of seawater-immersed TBI remain unclear. Mitochondrial dysfunction is a major cause of TBI-associated brain damage because it leads to oxidative stress, decrease in energy production, and apoptosis. Thus, the present study aimed to further elucidate the current understanding of the pathology of seawater-immersed TBI, particularly the role of mitochondrial dysfunction, using a well-defined rat model of fluid percussion injury and a stretch injury model comprising cultured neurons. The biochemical and pathological markers of brain-related and neuronal injuries were evaluated. Histological analysis suggested that seawater immersion enhanced brain tissue injury and induced a significant increase in apoptosis in rats with TBI. Additionally, lactate dehydrogenase release occurred earlier and at higher levels in stretched neurons at 24 h after seawater immersion, which was consistent with more severe morphological changes and enhanced apoptosis. Furthermore, seawater immersion induced more rapid decreases in mitochondrial membrane potential, adenosine triphosphate (ATP) content, and H+-ATPase activity in the cortices of TBI rats. In addition, the immunochemical results revealed that seawater immersion further attenuated mitochondrial function in neurons exposed to stretch injury. The increases in neuronal damage and apoptosis triggered by seawater immersion were positively correlated with mitochondrial dysfunction in both in vivo and in vitro models. Thus, the present findings strengthen the current understanding of seawater-immersed TBI. Moreover, because seawater immersion aggravates mitochondrial dysfunction and contributes to post-traumatic neuronal cell death, it is important to consider mitochondria as a therapeutic target for seawater-immersed TBI.

Immersion pulmonary edema: case reports from Oceania.

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 dysrhythmias in 16%. CONCLUSIONS: Previously reported associations of IPE such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, ascent or surfacing, tight wetsuit, aspiration and certain medications were identified. Cardiac conditions were frequent and included chronic disorders (valvular pathology, coronary artery disease) and transient disorders (dysrhythmias, transient myocardial dysfunction, takotsubo or stress cardiomyopathy). It is likely that the chronic cardiac disorders may have contributed to the IPE, whereas the transient cases could be either sequelae, contributors or coincidental to the IPE.

Immersion pulmonary edema: an analysis of 31 cases from Oceania.

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 associations such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, tight wetsuit, aspiration and certain medications were identified. This series supports the hypothesis that the elderly IPE subjects are likely to have comorbidities and be susceptible to IPE recurrences and fatalities unless the contributing factors can be identified and addressed.

Risk factors for immersion pulmonary edema in recreational scuba divers: a case-control study.

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. CONCLUSION: To reduce the risk of experiencing IPE, divers over 50 years of age or with hypertension, especially women, should avoid extensive physical effort, psychological stress, deep dives and NSAID intake before diving.