Diving at Altitude

I am the medical officer for Peace Corps Jordan. While I am not a diver, many Peace Corps volunteers and staff dive in Aqaba, in the Red Sea, at the southernmost point of the country. Because of the difference in elevation between Aqaba and Amman, divers are advised to spend the night in Aqaba in order to avoid the bends. One of our volunteers is living in a village at the southernmost end of the Dead Sea, at approximately 365 meters / 1,197 feet below sea level. This young man is 29 years old, a diver, and in good health. My questions are:

1. What are the long-term side effects of living for a prolonged period (two years) at approximately 1,200 feet below sea level?

2. Would this person need to take any precautions before diving in the Red Sea in Aqaba?

3. If he would need to be transported via medevac for any reason from Jordan, would he not be able to fly within a specific period?
  1. There is no evidence that living at depth, at least at such a small water-equivalent depth, has any deleterious effects. The barometric pressure at the surface of the Dead Sea is about 800mmHg (normal atmospheric pressure is 760mmHg). Prolonged subsea living, such as experienced by those divers exposed to saturation dives in underwater habitats (e.g., Tektite II at 50 feet/15 meters, or 1,150 mmHg), may have numerous side effects, ranging from decompression illness to dysbaric osteonecrosis (the death of portions of the long bones in the body in a proportion of those exposed to increased pressure). The dangers of Dead Sea living come more from exposure to the sun and the extreme salinity of the water.
  2. The young man should consider himself to be diving at altitude in the Red Sea in Aqaba (when coming from his subsea home); this is a theoretical answer to the question as there is no data to support the following proposition. Standard tables were designed for sea-level dives only. The Theoretical Ocean Depth (TOD) concept was suggested by NOAA (National Oceanographic and Atmospheric Administration) to cope with diving at altitude. NOAA looked at the difference in barometric pressures at various altitudes and recalculated the dive tables based upon the new equivalent water depth, both for fresh water and sea water. This calculation converted for the Dead Sea would add about three feet (one meter) to any given dive. This in turn means he should count each dive as being one stop deeper. The U.S. Navy tables recommend, in fact, that no alteration be made for dives at altitudes lower than 2,300 feet / 701 meters. A few dive computers use the Buhlmann correction for altitude, using the same principle as the TOD. Unfortunately, as they assume a sea-level starting point they would make an incorrect assumption for this diver.
  3. DAN's preliminary research findings indicate that waiting to fly or go to elevation after diving requires at least a 12-hour wait after a single no-stop dive and a wait for an extended surface interval beyond 12 hours after multiple dives in a single day before flying. If the diver developed symptoms of decompression illness and required a medical evacuation, there should be no problem if the plane could pressurize the cabin to 800mmHg. In a dire situation in which the diver requires transportation over a mountain pass or other elevation to reach a medevac aircraft, then he should breathe 100 percent oxygen during the trip to prevent or lessen any effect that altitude may have on symptoms of decompression illness. 
Posted in

No Comments


Categories

 2016 (119)
After anaesthesia Air Quality Altitude sickness Annual renewal Apnea Arthroscopic surgery Bag valve mask Bandaids Barbell back squat Bench press Boyle's Law Boyle\'s Law Boyle\\\'s Law Boyle\\\\\\\'s Law Breath hold Breath-hold Buoyancy Burnshield CGASA CO2 Camera settings Cancer Remission Cancer Cape Town Dive Festival Carbon dioxide Charles' Law Charles\' Law Charles\\\' Law Charles\\\\\\\' Law Coastalexcursion Cold Water Cold care Cold Conservation Contaminants Corals DAN Profile DAN Researchers DAN medics DAN report DCI DCS DReams Dalton's Law Dalton\'s Law Dalton\\\'s Law Dalton\\\\\\\'s Law Decompression Illness Decompression Sickness Decompression illsnes Dive Instruction Dive Instructor Dive accidents Dive health Dive medicines Dive medicine Dive safety Dive staff Diveleaders Divers Alert Diving career Diving emergencies Diving injuries Diving suspended Diving Dr Rob Schneider EAP Ear pressure Ears injuries Emergency plans Environmental impact Equipment care Exercise Eye injuries FAQ Fatigue First Aid Equipment First Aid kits Fish Fitness Francois Burman Free diving Freediver Gas laws Gastric bypass Gordon Hiles HELP Health practitioner Hot Hypothermia Indian Ocean Inert gas Instructors International travel Irritation Kids scubadiver Labour laws Legislation Leukemis Liability Risks Maintenance Medical Q Medical questionaire Medical statement Middle ear pressure Military front press Mycobacterium marinum Nitrox Non-rebreather Mask Nosebleeds O2 providers O2 servicing OOxygen maintenance Ocean pollution Orbital implants Oronasal mask Oxygen Cylinder Oxygen Units Oxygen deicit Oxygen ears Oxygen equipment Oxygen masks Part 3 Plastic Pool Diving Radio communications Rashes Report incidents Rescue training Resume diving SABS 019 Safety Save our seas Science Scuba Injury Scuba children Scuba dive Scuba health Scubalearners Skin Bends Skin outbreak Skin rash Snorkeling Sodwana Bay Squeezes Supplemental oxygen Surgeries Surgery The truth Thermal Notions Tides Travel tips Tweezers Underwater photographer Underwater pho Valsalva manoeuvers Vasvagal Syncope White balance Winter Wreck dive Youth diver abrasion air-cushioned alert diver altitude antibiotics antiseptics bandages bent-over barbell rows breathing air checklist child clearances closed circuit scuba currents dead lift decongestants dehydration dive injuries dive medicing dive ready child diver rescue dive diving attraction doctors domestic travel dri-suits dry mucous membranes dry ear spaces electroytes emergency action plans emergency assessment equalizing exposure injuries flexible tubing health hospital humidity immersion pulmonary edema (IPE join DAN marine pathogens medical procedures medical risk assesment mucous membranes nasal steroids nasal newdivers nitrogen bubbles off-gassed operating theatre outgas pain plasters post dive preserve rebreather mask rebreathers risk areas saturation scissors scuba equipment scuba single use sinus infections strength tecnical diver thermal protection training trimix unified standards warmers water quality