Inert gas washout FAQ

Inert gas washout 

DAN medics and researchers answer your questions about dive medicine.

My students asked what happens to the nitrogen bubbles in untreated decompression sickness (DCS). I guessed that they eventually get reabsorbed or off-gassed via the lungs. What is the best answer?
Divers accumulate nitrogen (and/or other inert gases in their breathing mix) while diving. The deeper and longer the dive, the more gas accumulates. In cases of DCS, the inert gas load exceeds the tissues’ capacity, so bubbles form.
Gas enters the body through the lungs, moves into the circulatory system and then into other tissues. Offgassing occurs by the same mechanism in reverse: Inert gas moves from the body’s tissues into the bloodstream and then into the lungs, where it is exhaled. A diver off-gasses when in shallow water after having been in deeper water (during ascent and while performing a decompression stop or safety stop, for example). Offgassing continues after the diver exits the water. The human body has no means by which to indefinitely retain gas or bubbles.
The vast majority of the inert gas is off-gassed within a few hours, and almost all of it leaves recreational divers’ bodies within about 24 hours. Because the bulk of excess inert gas is eliminated within a day, thefirst onset of DCS symptoms is unlikely after 24-hours following a dive (except in special circumstances such as saturation diving or subsequent altitude exposure, for example).
Bubbles cause inflammation and local tissue injuries. The larger the bubble load, the more severe the injury and the faster the onset. Hyperbaric chamber treatment within the first 24 hours can eliminate gas and bubbles while the injury is still occurring. After about 24 hours, the injury has already occurred. Bubbles are no longer present, but the injury persists. Hyperbaric treatment after the first day can still be very helpful by promoting healing and recovery.
Although leaving DCS untreated is not recommended, its general progression is improvement over time. Some divers who do not get treated recover completely, but others have persistent problems that range from mild to severe.
For more information about inert gas, DCS and hyperbaric chamber treatment, visit DAN.org or call the DAN Medical Information Line at +1 (919) 684-2948.
— Frances Smith, MS, EMT-P, DMT

Inert Gas Washout

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