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, the first 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.  OR in Southern Africa: +27 828 10 60 10
— Frances Smith, MS, EMT-P, DMT

Categories

 2019
 2018
 2016
Accidents Acid reflux Acute ailments After anaesthesia Air Quality Air exchange centre Air hose failure Airway control Altitude changes Altitude sickness Ama divers Amino acids Anaerobic Metabolism Annual renewal Apnea Apnoea Arterial gas embolism Arthroscopic surgery Aurel hygiene BCD BHP BLS Back adjustment Back pain Back treatment Backextensors Badages Bag valve mask Balancing Bandaids Barbell back squat Basic Life Support Batteries Bench press Benign prostate hyperplasia Blood flow Blurred vision Bone fractures Bouyancy compensators Boyle's Law Boyle\'s Law Bradycardia Brain Breast Cancer Breath Hold Diving Breath hold Breath-hold Breathing Gas Breathing Broken bones Bruising Buoyancy Burnshield CGASA CMAS CO2 COVID-19 CPR Cabin pressure Camera settings Cancer Remission Cancer treatments Cancer Cannabis and diving Cannabis Cape Town Dive Festival Cape Town Carbon dioxide Cardio health Cardiological Cardiomyopathy Chamber Safety Chamber science Charging batteries Charles' Law Charles\' Law Charles\\\' Law Charles\\\\\\\' Law Charles\\\\\\\\\\\\\\\' Law Chemotherapy Chest compressions Chiropractic Citizen Conservation Cleaning products Coastalexcursion Cold Water Cold care Cold Commercial diving Commercial schools Compressed gas Conservation Contaminants Contaminated air Coral Conservation Coral Reefs Corals Core strength Courtactions Crohns disease Crowns Crystal build up Crystallizing hoses Cutaneous decompression DAN Courses DAN Profile DAN Researchers DAN medics DAN report DCI DCS Decompressions sickness DCS theories DCS DEMP DM training DReams Dalton's Law Dalton\'s Law Dalton\\\'s Law Dalton\\\\\\\'s Law Dalton\\\\\\\\\\\\\\\'s Law Deco dives Decompression Illness Decompression Sickness Decompression illsnes Decompression treatment Decompression Delayed Offgassing Dental Diaphragms Diseases Dive Chamber Dive H Dive Industry Dive Instruction Dive Instructor Dive Pros Dive Research Dive Training Dive Travel Dive accidents Dive buddies Dive computers Dive excursions Dive fitness Dive gear Dive health Dive medicines Dive medicine Dive operators Dive safety Dive safe Dive staff Diveleader training Diveleaders Diver Profile Diver infliencers Diver on surface Divers Alert Diving Kids Diving Trauma Diving career Diving emergencies Diving emergency management Diving fit Diving guidelines Diving injuries Diving suspended Diving Dizziness Domestic Donation Dowels Dr Rob Schneider Drysuit diving Drysuit valves Drysuits EAPs EAP Ear pressure Ear wax Ears injuries Education Electronic Emergency action planning Emergency decompression Emergency plans Emergency underwater Oxygen Recompression Emergency Enviromental Protection Environmental factors Environmental impact Environmental managment Equipment care Evacuations Evacuation Evaluations Even Breath Exercise Exhaustion Extended divetime Extinguisher Extreme treatments Eye injuries FAQ Failures Fatigue Faulty equipment Fillings Fire Coral Fire Safety Firefighting First Aid Equipment First Aid Training First Aid kits Fish Identification Fish Fitness Training Fitness to dive Fitness Flying Francois Burman Free Student cover Free diving Free flow Freedive Training Freediver Freediving performance Gas Density Gas laws Gas mixes GasPerformance Gases Gastoeusophagus Gastric bypass Gastroenterologist Gear Servicing Gordon Hiles Gutt irritations HELP HIRA Haemorhoid treatment Hazard Description Hazardous Marine life Hazardous marinelife Health practitioner Heart Attack Heart Health Heart Rate monitor Heart rates Heart rate Heart Heat stress Helium High temperatures Hip strength Hippocampus Hot Humans Hydrate Hydration Hydrogen Hydroids Hydrostatic pressure Hyperbaric Chamber Hyperbaric research Hypothermia Hypoxia Immine systems In Water Recompression Indemnity form Indian Ocean Indonesia Inert gas Infections Injections Instinct Instruction Instructors Insurance Integrated Physiology International travel International Interval training Irritation Joint pain KZN South Coast Kidneys Kids scubadiver KwaZulu Natal Labour laws Laryngospasm Learning to dive Legal advice Legislation Leukemis Liability Risks Liability releases Liability Life expectancy Lifestyle Live aboard diving Low blood pressure Low pressure deterioration Low volume masks Lung function Lung injuries Lung surgery Lung MOD Maintenance Malaria Mammalian Dive Response Mammalian effect Marine Scientists Marine parks Marinelife Master scuba diver Maximum operating depth Medical Q Medical emergencies Medical questionaire Medical statement Medication Middle ear pressure Mike Bartick Military front press Mixed Gas Mono Fins Mooring lines More pressure Motion sickness Muscle pain Mycobacterium marinum Nausea Nautilus Neck pain Neurological assessments Nitrogen build up Nitrox No-decompression Non-rebreather Mask Normal Air Nosebleeds O2 providers O2 servicing OOxygen maintenance Ocean pollution Open water divers Orbital implants Oronasal mask Out and about Oxygen Cylinder Oxygen Units Oxygen deficit Oxygen deicit Oxygen dificiency Oxygen ears Oxygen equipment Oxygen masks Oxygen supply Oxygen therapy Oxygen P J Prinsloo PFI PJP Tech Part 3 Phillipines Photography Physioball Physiotherapy Pills Pistons Planning Plastic Pneumonia Pneumothorax Pollution Pool Diving Preparation Prepared diver Press Release Professional rights Provider course Pulmanologist Pulmonary Bleb Pulse Punture wounds Purge RAID South Africa RCAP Radio communications Range of motion Rashes Rechargeable batteries. Recompression chamber Recompression treatment Recompression Recycle Regulator failure Regulators Regulator Remote areas Renewable Report incidents Rescue Procedure Rescue breathing Rescue breaths Rescue training Rescue Resume diving Risk Assessments Risk assesments Risk assessment Risk elements Risk management SABS 019 Safety Stop Safety Saturation Diving Save our seas Science Scombroid Poisoning Scuba Air Quality Scuba Injury Scuba Instructor Scuba children Scuba dive Scuba health Scubalearners Sea Horses Sealife Shark conservation Shark diving Sharks Shoulder strength Sideplank Signs and Symptoms Sit-ups Skin Bends Skin outbreak Skin rash Snorkeling Snorkels Sodwana Bay South Africa Spinal pain Splits Squeezes Stability exercise Standars Stay Fit Stents Step ups Stroke Submerged Sudafed Sulawesi Supplemental oxygen Surface supplied Air Surfaced Surgeries Surgery Suspension training TRavel safety Tabata protocol Tattoes Technical Diving The Bends The truth Thermal Notions Tides Tips and trick Tooth squeeze Transplants Travel tips Travel Tweezers Unconsciousness Underwater photographer Underwater pho Urinary retention. Vaccines Vagus nerve Valsalva manoeuvers Vape Vaping Vasopressors Vasvagal Syncope Venting Volatile fuels Washout treatments Wastewater Water Resistance Water Weakness Weigang Xu West Papua Wetsuit fitting Wetsuits White balance Winter Woman in diving Work of Breathing Workout Wound dressings Wreck dive Wreckdiving Yoga Youth diver abrasion air-cushioned alert diver altitude anemia antibiotics antiseptics bandages barodontalgia bent-over barbell rows bioassays body art breathing air calories burn carbon dioxide toxicity cardiovascular checklist chemo port child clearances closed circuit scuba currents cuts dead lift decompression algorithms decongestants decongestion dehydration dive injuries dive medicing dive ready child dive reflex dive tribe diver in distress diver rescue diver training dive diving attraction doctors domestic travel dri-suits drowning dry mucous membranes dry suits dry e-cigarettes ear spaces elearning electrolyte imbalance electroytes emergency action plans emergency assessment equalizing exposure injuries eyes fEMAL DIVERS fire rescue fitnes flexible tubing frediving freedivers gas bubble gas poisoning gastric acid health heartburn histidine hospital humidity immersion pulmonary edema (IPE join DAN knee longevity lower stress marine pathogens medical issues medical procedures medical risk assesment medications mental challenge micro-organisims minor illness mucous membranes nasal steroids nasal near drowning nematocysts neurological newdivers nitrogen bubbles off-gassed operating theatre operations orthopeadic outgas pain perforation phillippines physical challenges pinched nerves plasters polyester-TPU polyether-TPU post dive posture preserve prevention psychoactive pulmunary barotrauma rebreather mask rebreathers retinal detachment risk areas safety stops saturation scissors scuba equipment scuba single use sinus infections smoking snorkeling. spearfishing stings strength sub-aquatic swimmers ears tattoo care tecnical diver thermal protection toxicity training trimix unified standards vision impaired warmers water quality