Decompression Sickness Treatment Research Articles

Oral Health Complications of SCUBA Diving

OBJECTIVE This review aims to assess the specific oral health complications associated with SCUBA diving, including barodontalgia, barosinusitis, and temporomandibular joint (TMJ) disorders, and to examine the dental implications of hyperbaric oxygen therapy (HBOT) used in decompression sickness treatment. Additionally, this review identifies gaps in the literature and suggests areas for further research to improve dental care guidelines for divers. MATERIALS AND METHODS A systematic literature search was conducted using PubMed and Scopus databases from 2004 to 2024, focusing on terms such as "barodontalgia," "dental barotrauma," and "diving dentistry." From 77 initial articles, 25 studies were selected based on relevance to pressure-induced oral complications, diving-related barotrauma, and dental management for SCUBA divers. RESULTS The review identifies barodontalgia as a prevalent issue, commonly triggered by untreated caries or defective restorations, with symptoms intensified by pressure changes. TMJ disorders, linked to prolonged clenching on diving mouthpieces, and sinus-related barotrauma also emerged as significant concerns. Preventive measures, including regular dental checkups, use of resin-based cements, and customized mouthpieces, are recommended to reduce risks. Furthermore, the review highlights a need for larger, controlled studies across diverse diver populations to validate current recommendations and develop accessible guidelines, especially for recreational divers who may lack access to specialized dental care.

A review of diving practices and outcomes following the diagnosis of a persistent (patent) foramen ovale in compressed air divers with a documented episode of decompression sickness.

The presence of a persistent (patent) foramen ovale (PFO) increases the risk of decompression sickness (DCS) whilst diving with pressurised air. After the diagnosis of a PFO, divers will be offered a number of options for risk mitigation. The aim of this study was to review the management choices and modifications to diving practices following PFO diagnosis in the era preceding the 2015 joint position statement (JPS) on PFO and diving. A retrospective study was conducted of divers sourced from both the Alfred Hospital, Melbourne and the Divers Alert Network Asia-Pacific during the period 2005-2015. Divers were contacted via a combination of phone, text, mail and email. Data collected included: diving habits (years, style and depths); DCS symptoms, signs and treatment; return to diving and modifications of dive practices; history of migraine and echocardiography (ECHO) pre- and post-intervention; ECHO technique(s) used, and success or failure of PFO closure (PFOC). Analyses were performed to compare the incidence of DCS pre- and post-PFO diagnosis. Seventy-three divers were interviewed. Sixty-eight of these returned to diving following the diagnosis of PFO. Thirty-eight underwent PFOC and chose to adopt conservative diving practices (CDPs); 15 chose PFOC with no modification to practices; 15 adopted CDPs alone; and five have discontinued diving. The incidence of DCS decreased significantly following PFOC and/or adoption of conservative diving practices. Of interest, migraine with aura resolved in almost all those who underwent PFOC. Many divers had already adopted practices consistent with the 2015 JPS permitting the resumption of scuba diving with a lowering of the incidence of DCS to that of the general diving population. These results support the recommendations of the JPS.

Decompression Sickness Treatment Using a Pressure Suit After Loss of Spacecraft Atmosphere.

BACKGROUND: Loss of spacecraft atmosphere (LOA) during Earth-Moon transit may require up to 144 h of pressure suit operations. This work investigates the feasibility of DCS treatment in this paradigm and discusses the operational and engineering implications.METHODS: Three scenarios of LOA-induced DCS were considered: a permanent LOA secondary to a 0.25-in (0.64 cm) hole (unrecoverable cabin leak), a transient LOA, and a permanent LOA with early suit over-pressurization (beyond suit specification). Each was simulated in the context of the current Orion spacecraft operational concept with regards to atmosphere and anticipated cabin depress profile. Probability of DCS symptom resolution (P(SR)) was estimated using the previously derived Hypobaric DCS Treatment Model, with ΔP calculated from a Three Region Well-Stirred Tissue (3RWT) bubble dynamics model. Analysis was conducted and analogies drawn from experiences with the development and testing of the Orion Crew Survival System (OCSS).RESULTS: Maintaining 8 psia at 100% Fio₂ following LOA resulted in an eventual halt and regression of bubble growth with a P(SR) of 87% (at 8 h, time to symptom onset (Ts) = 105 min, with ambulation). If cabin atmosphere was not restored and psia dropped to 4.3, bubble growth returned, but again eventually slowed and regressed over time (P(SR) = 75% at 21 h). If the leak is repaired within the 8-h period, 8 psid (psia = 22.7) resulted in P(SR) of greater than 95%. Similarly, if the suit was over-pressurized (12 psid/psia) within 3 h after LOA, P(SR) exceeded 95%.DISCUSSION: A launch/entry pressure suit represents a contingency option for DCS management in the event of LOA.Greene MR, Jacobs SE. Decompression sickness treatment using a pressure suit after loss of spacecraft atmosphere. Aerosp Med Hum Perform. 2020; 91(7):571-577.

Benefits of Escin for Decompression Sickness in Bama Pigs by Endothelial-Targeting Protection.

Endothelial dysfunction has been considered as pivotal in the pathogenesis of decompression sickness (DCS) and contributes substantively to subsequent inflammatory responses. Escin is well known for its endothelial protection and anti-inflammatory properties, and its protection against DCS has been proved in a rat model. This study aimed to further investigate the protection of escin against DCS in swine. Sixteen swine were subjected to a two-stage experiment with an interval of 7 days. In each stage, 7 days before a simulated air dive, the swine were treated with escin or saline. The first group received a successive administration of escin for 7 days prior to the first dive and saline for 7 days prior to the second; the second group was treated with saline and then escin. After decompression, signs of DCS and circulating bubbles were monitored, and blood was sampled for platelet count and determination of inflammatory and endothelial related indices. The death rate of DCS was markedly decreased in swine treated with escin compared with that in animals treated with saline, though not statistically significant due to the limited number of animals. Escin had no effect on bubble load but significantly ameliorated platelet reduction and endothelial dysfunction, as well as oxidative and inflammatory responses. The results further suggest the beneficial effects of escin on DCS by its endothelia-protective properties, and escin has the potential to be a candidate drug for DCS prevention and treatment.

Perfluorocarbon in Delayed Recompression with a Mixed Gender Swine Model of Decompression Sickness.

Perfluorocarbons (PFC) are fluorinated hydrocarbons that dissolve gases to a much greater degree than plasma and hold promise in treating decompression sickness (DCS). The efficacy of PFC in a mixed gender model of DCS and safety in recompression therapy has not been previously explored. Swine (25 kg; N = 104; 51 male and 53 female) were randomized into normal saline solution (NSS) or PFC emulsion treatment groups and subjected to compression on air in a hyperbaric chamber at 200 fsw for 31 min. Then the animals were decompressed and observed for signs of DCS. Afterwards, they were treated with oxygen and either PFC (4 cc · kg-1) or NSS (4 cc · kg-1). Surviving animals were observed for 4 h, at which time they underwent recompression therapy using a standard Navy Treatment Table 6. After 24 h the animals were assessed and then euthanized. Survival rates were not significantly different between NSS (74.04%) and PFC (66.67%) treatment groups. All swine that received recompression treatment survived to the end of the study and no seizures were observed in either PFC or NSS animals. Within the saline treated swine group there were no significant differences in DCS survival between male (75.00%, N = 24) and female (73.08%, N = 26) swine. Within the PFC treated swine, survival of females (51.85%, N = 27) was significantly lower than males (81.48%, N = 27). In this large animal mixed gender efficacy study in DCS, PFC did not improve mortality or spinal cord injury, but appears safe during recompressive therapy. Gender differences in DCS treatment with PFC will need further study.Cronin WA, Hall AA, Auker CR, Mahon RT. Perfluorocarbon in delayed recompression with a mixed gender swine model of decompression sickness. Aerosp Med Hum Perform. 2018; 89(1):14-18.

Endothelia-Targeting Protection by Escin in Decompression Sickness Rats

Endothelial dysfunction is involved in the pathogenesis of decompression sickness (DCS) and contributes substantively to subsequent inflammatory responses. Escin, the main active compound in horse chestnut seed extract, is well known for its endothelial protection and anti-inflammatory properties. This study aimed to investigate the potential protection of escin against DCS in rats. Escin was administered orally to adult male rats for 7 d (1.8 mg/kg/day) before a simulated air dive. After decompression, signs of DCS were monitored, and blood and pulmonary tissue were sampled for the detection of endothelia related indices. The incidence and mortality of DCS were postponed and decreased significantly in rats treated with escin compared with those treated with saline (P < 0.05). Escin significantly ameliorated endothelial dysfunction (increased serum E-selectin and ICAM-1 and lung Wet/Dry ratio, decreased serum NO), and oxidative and inflammatory responses (increased serum MDA, MPO, IL-6 and TNF-α) (P < 0.05 or P < 0.01). The results suggest escin has beneficial effects on DCS related to its endothelia-protective properties and might be a drug candidate for DCS prevention and treatment.

Polarization of macrophages in the blood after decompression in mice.

The veins are a major site of bubble formation after decompression and the lung is a target organ of bubbles. Bubble-induced inflammation has been implicated in the pathogenesis of decompression sickness (DCS). Macrophages play a central role in the inflammation, and macrophage polarization is closely related to the pathogenesis of some lung diseases. This study aimed to investigate the blood macrophage polarization in mice after decompression. BALB/c mice were exposed to hyperbaric air for 60 minutes, and rapid decompression was performed to induce DCS. Slow decompression and hyperoxia (150 kPa, 60 minutes) served as control groups, and hyperbaric oxygen (HBO; 250 kPa, 60 minutes) was employed for DCS treatment. Macrophage phenotype was determined by flow cytometry, and cytokines related to macrophage polarization were measured by enzyme-linked immunosorbent assay. Our results showed rapid decompression significantly induced the shift to M1 phenotype, which was not observed in slow decompression group, HBO and hyperoxia groups. These changes were consistent with the change in blood tumor necrosis factor α level. Moreover, any treatment could significantly increase the M2 macrophages, but blood interleukin-10 remained unchanged after different treatments. In addition, the blood and lung levels of monocyte chemoattractant protein-1 and intercellular adhesion molecule-1 increased significantly after rapid decompression, but reduced markedly after HBO treatment. Taken together, rapid decompression is able to induce the shift to M1 phenotype in blood macrophages, which may then migrate into the lung involving decompression-induced lung injury.

Is centralization in emergency rural medicine always right? Lessons learned from two cases of decompression sickness

The cases of two patients with decompression sickness (DS) are described to add to the discussion about whether centralization, especially when accompanied by air-medical transport, is always justifiable in island emergency medicine. One patient received hyperbaric oxygen (HBO) treatment on another island after island-to-island transfer by boat; the other received HBO treatment on a ship that was anchored, by chance, close to the island where he became ill. Both cases had a good outcome. Island-to-island transport and within-island treatment, rather than island-to-urban-center transport, was effective, indicating that treatment centralization may not be the most effective protocol all cases. A DS treatment strategy is proposed for use in this geographic area; however, DS occurring on remote islands highlights the wider issue of the centralization of health services.

Place de l’aspirine dans le traitement médicamenteux de l’accident de désaturation

We have performed a survey on the use of aspirin in decompression sickness (DCS) treatment in French hyperbaric centers'. We also conducted a review of literature to determine if aspirin was beneficial to treat human victims of DCS. Prospective observational study investigating French hyperbaric centers' prescription of aspirin to DCS' divers victims. The question we asked by mail or phone to French hyperbaric centers was: Do you give some aspirin to a diver with DCS if this treatment has not been given yet (on the site of accident). A large majority of French hyperbaric centers (77.5%) consider aspirin in DCS treatment. However this practice is not consensual. There is no evidence from the literature to support the efficiency of aspirin in DCS. Although aspirin is widely used for DCS treatment in France, more research is needed to determine if aspirin is useful.

Use of Decompression Computers as Dive Profilers and Electronic Logbooks, and in the Management of Decompression Sickness Treatment

Many decompression computers developed for the SCUBA leisure market over the past five years have the facility to store profile information which can be interrogated through PC interfaces. This capability allows for a variety of dive parameters to be stored, and subsequently downloaded [I]. The Natural Environment Research Council (NERC) Cent re for Oiving at Ounstaffnage, has been using a number of models of decompression computers over the past two years. Their use has been as dive loggers, and examples of the parameter categories recorded, and at what level of precision, are presented here in brief. The NERC Centre also accommodates a hyperbaric treatment facility. The availability of the software and PC interfaces necessary to download from most models of dive computers, has allowed for the incorporation of actual recorded dive details within the treatment management process. The benefits of having that additional information, usually at the commencement of the treatment, are discussed below. lt is not intended here to give a detailed product guide of downloadable computers, and a systematic investigation of all types of computers has not been attempted. The purpose of this note is to summarise the uses of such computers to the diving at work and hyperbaric treatment communities. Use of decompression computers as dive profilers and electronic logbooks