Acute ischemic colitis during scuba diving: Report of a unique case

The presentation of clinical symptoms due to decompression during diving, varies significantly, as mainly minor disturbances for the gastrointestinal tract in particular have been reported. The following case debates whether diving can cause severe symptoms from the gastrointestinal system. We describe a clinical case of ischemic colitis presented in a 27-year-old male, who manifested abdominal pain while in the process of scuba diving 20 meters undersea, followed by bloody diarrhoea as soon as he ascended to sea level. Taking into account his past medical history, the thorough, impeccable clinical and laboratory examinations and presence of no other factors predisposing to ischemia of the colon, we assume that a possible relationship between diving conditions and the pathogenesis of ischemic colitis may exist. This unusual case might represent a hematologic manifestation of decompression sickness, due to increased coagulability and/or transient air emboli, occurring during a routine scuba diving ascent to sea level.

Why Do Divers Want to Liveaboard?Measuring SCUBA Divers’Motivations of Liveaboard Using a Cruise Perspective

Diving is a recreational activity of growing significance in many countries.In the recreational SCUBA diving industry,a liveaboard service offers tourists to stay on board for several nights and that allows time to travel to more distant dive sites.SCUBA diving belongs to an adventure tourism,while cruise is much more leisure tourism activity.However,they share a similar travel mode,so it is very interesting to find the reason behind.Do cruise tourists be the potential diving tourists?The paper adopted the cruising motivation scale for diving tourists to develop a scale for SCUBA divers’motivations of liveaboard.Convenience sampling was used to select participants for the study.After exploratory factor analysis(EFA),the results showed that there were six dimension of SCUBA divers’liveaboard motivation,and the added dimension of divers’preference was valid.Finally,a measurement scale of SCUBA divers’liveaboard motivation was proposed in this study,and the discussion and implication were also presented in the paper.

Integrating Remote Sensing and Field Survey to Map Shallow Water Benthic Habitat for the Kingdom of Bahrain

Identification and classification, as well as mapping of marine habitats, are of primary importance to plan management activities, especially in disturbed ecosystems like the ones in the marine areas of Bahrain. Remotely sensed Landsat-8 imagery coupled with field survey was used to identify, classify and map the benthic habitats in Bahrain marine area. The used geospatial techniques include advanced image processing procedures, which comprise of radiometric and atmospheric corrections, sun glint removal, water depth correction and image classification. Extensive ground-truthing analyses through in-situ field surveys by a team of scuba divers were conducted in October 2014 and June 2015 to inform and refine the classifications. The variables collected from this survey included physical and chemical characteristics of the water, habitat type, substrata, fauna and flora. A total of 176 field points were collected and utilized to perform an accurate assessment of the image classification. Initial habitat classification resulted in 20 habitat categories. However, due to the inability of the Landsat-8 sensors to accurately discriminate that level of classification, categories were merged into seven classes. The derived map shows that the benthic marine habitats of Bahrain consist of deep water （2,523 km2）, rock （1,738 km2）, sand （1,191 km2）, deep water/sand （1,006 km2）, algae （922 km2）, seagrass （591 km2） and corals （275.50 km2）. Although limited by the spatial and spectral resolutions of Landsat 8, the used methods produced a suitable map of the benthic habitats within the marine area of Bahrain with an overall accuracy of 84.1%. The use of very high spatial resolution satellite imagery will most likely increase such accuracy significantly.

A Short Report on Decompression Sickness Incidents in Andaman and Nicobar Islands

Objectives: Due to presence of extensively fascinating coral reef ecosystem in the continental shelf of Andaman and Nicobar Islands, people from all over the world visit these islands of India to indulge in recreational diving. An increased participation figure has also elevated the number of divers at risk for Decompression Sickness (DCS). Despite this, no scientific data are available on DCS incidents from India. Present study is aimed to evaluate the DCS incidents reported in these islands, treatment provided, and the outcome of the treatment. An attempt has also been made to calculate the approximate frequency of DCS in comparison to the participation figure. Methods: Study design is retrospective data analyses of a recompression chamber. Naval Diving Unit Port Blair has the only active decompression chamber available in the islands, and Govind Ballabh Pant Hospital Port Blair was used to collect information on DCS incidents that occurred during the mentioned period. Due to lack of authenticated generalized documents of divers’ health history and dive logs, the scanty information was gathered from the dive centres on the basis of personal interviews/communications among the SCUBA diving instructors. Results: A total of nine cases were reported during the span of last four and half years, and thus approximate frequency of DCS in Andamans was 0.2/10000 divers year. All of the patients recovered completely after receiving the Hyperbaric Oxygen Therapy (HBOT), with no residual symptoms. Conclusions: Incident rate of DCS in Andamans is lower than that in many other parts of the world;possible reason could be under-reporting of less severe DCS cases. During the study period, the number of DCS type II incidents presented for the treatment was higher than that of DCS type I incidents. HBOT proved a complete success in treating DCS cases in the island.

Heart Rate Variability from Underwater Spiroergometry:How Meaningful?

Cardiovascular fitness of divers is overwhelmingly performed using bicycle ergometry.A more sport-specific alternative presents fit2dive,an underwater spiroergometry system.Purpose of this exploratory study:using fit2dive to investigate the diagnostic value of measures of heart rate variability(HRV)after markedly increasing physical load.Ten scuba divers employed the fit2dive system and increased fin-swimming speed until exhaustion.Breathing gas consumption(VE)and heart rate(HR)were measured.A three-lead ECG was recorded to analyze for time and frequency domain HRV-measures.VE increased from 16.5±6.5 to 68.3±26.6 L/min.HR increased from 96±13 beats/min(mean±SD)at rest to 170±14 beats/min before exhaustion.Global variability(SDNN:132±42 vs.54±17 ms)decreased along with two measures of parasympathetic activity(RMSSD:59±31 vs.24±16 ms;pNN50:22%±12%vs.3%±3%).Measures from the frequency domain decreased[low frequency(LF):3167±2651 vs.778±705 ms_(2)]or remained unaltered[high frequency(HF):885±652 vs.431±463 ms^(2)].Thus,LF/HF decreased from 4.3±2.3 to 2.5±1.4.The sports-specific fit2dive can help assessing diving fitness by employing HRV measures.However,this study supports the view that these measures much depend on HR.Thus,HRV measures regarding altered autonomic control during exercise will lead to serious misinterpretation:as HR increases,variability decreases.