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30th Dec, 2019 by: Himalayan Magic Treks
Learn what is Gamow bag and how to use it correctly in high-altitudes
Everything you need to knowabout Gamow Bag
What is a Gamow Bag?
Gamow Bag is an inflatable pressure bag used mountain climbers in high altitudes to prevent altitude sickness by raising the surrounding pressure. It is a hyperbaric bag which length about 7 feet, large enough for a person to rest inside and treat them for altitude sickness. The pressure from 105 mm-Hg to 220 mm-Hg can be maintained inside the bag resulting in decrease of altitude from 1000 to 3000 meters inside the chamber.
Gamow Bag becomes cylindrical when it is inflated. It is coated with nylon which is light but very durable in extreme temperatures. It is covered by nylon straps (tie down straps) that gives rigidity and limit the movement of the bag. When it is deflated, it can be enfolded which makes it easier to carry for long trips and trekking in high altitudes so it is easily portable. It is categorized as a Class II medical device that should be only used temporarily when there is an emergency.
Trekking Routes Reguired Gamow Bags?
Some trekking such as Everest high passes trek, Khumbu Icefall trek or Dhaulagiri Circuit trek requireds Gamow Bag. However peak climbing and mountain expeditions requires it. Normally in trekking, we do't use Gamow Bags.
History of Gamow Bag:
Igor Gamow was the first person to invent the Gamow bag in 1987. Igor Gamow first designed “The Bubble” to study the effect of high altitude on a person. He later re-designed it into a medical device-Gamow Bag which can be used in the high-altitude environment. This is one of the significant equipment during high peak climbing and expeditions. Wyoming Centennial Everest Expedition (WCEE) first practically tested the Gamow Bag on Mount Everest in 1988 with the team of about 35 members.
How does a Gamow Bag Works? Function of Gamow Bag?
Altitude Sickness is the greatest challenges during climbing peaks and high-mountains. Even with multiple precautions and prevention, one might end up getting the AMS (Altitude Mountain Sickness) and serious threat like HAPE and HACE. The situation can be very dangerous if there is no quick descent and medical care.
But the descent from high altitude is not easy and comfortable. Most of the victims are unable to descent physically on their own. It requires another person to carry the victim in the back or in a container and take him/her to lower level. This work is extremely exhausting and could also be dangerous to the person carrying the victim. Emergency evacuation like helicopter is not always possible in every area. There should be favorable weather and landing spot for a successful air evacuation. Natural disaster like avalanche and landslides might occur which worsen the problem.
Gamow Bag is the life-saving first aid device, most needed at these situations. It is very effective in emergency circumstances. The victim is not required to move physically and the person treating the victim also don’t need to give extreme effort, making it very easy and reliable to use.
The table below shows the data from the research by WCEE of altitude changing from environment to pressurized Gamow Bag:
| Environment Altitude- | Altitude Inside Gamow Bag= | Reduced altitude |
|---|---|---|
| 3900 m | 2299 m | 1601 m |
| 4800 m | 3028 m | 1772 m |
| 5400 m | 3505 m | 1895 m |
| 6600 m | 4436 m | 2164 m |
| 7800 m | 5335 m | 2465 m |
| 8700 m | 5986 m | 2714 m |
Four major high altitude sickness (with symptoms):
- Acute Mountain Sickness (AMS)
-Headache
-Insomnia (sleeplessness)
-Loss of Appetite
-Nausea
–Ataxia (loss of body control) - High Altitude Pulmonary Edema (HAPE)
-Cough
-Dyspnea (Difficulty in Breathing)
-Cyanosis (turning of skin to blue color due to insufficient oxygen supply)
-Irregular respiratory rate
-Fatigue (feeling of extreme weak and tired) - High Altitude Cerebral Edema (HACE)
-Headache and unconsciousness
-Papilloedema (swelling of optic nerve)
-Ataxia
-Hallucinations - Retinal Hemorrhage
-Headache
-Nausea
-Insomnia
-Lassitude / fatigue
-Distorted vision and seeing floaters, cobwebs, haze in the vision
Major Parts of Gamow Bag:
Labels of Gamow bag
The parts of the Gamow Bag differs with the altitude and availability. Below are the major components of the Gamow Bag:
- Intake Valve
Intake valve or bleed valve is in located at the side of the foot of the Gamow bag. It is attached to foot pump by a hose/tube to pressure the bag. - Relief Valve
The relief valve is used to limit the pressure of 2 psi inside the bag. Always be sure to check if relief valve is working or not. If it is not working, you should immediately fix it or replace it. It lies at the side of head (window). - Windows
The windows in the Gamow bag is made up of plastic and is transparent. It lets the victim to communicate with the trainer or guide. The light passes inside the bag through the window and also helps calm down the victim from any sort of fear. The victim may use additional blankets and clothes for more warmth inside the bag. - Zipper
The zipper of the Gamow bag is flexible and leak-proof. It lets the victim to both enter and exit the bag. Be sure to leave the zipper in open state while not using it to fold it more effectively. - Manometer
Manometer is attached in the Gamow bag to monitor the pressure and to check if the bleed valve is working or not. - Foot pump
A foot pump or any other pump is used to fill the air pressure inside the bag. The air compressor requires other accessory compressor hose. - Straps
There are normally five straps in Gamow bag. They helps to restrict the movement of the chamber and provides the rigidity. There are two carry handle straps that is useful when carrying the bag.
How to Use the Gamow Bag:
Step 1: Preparing the Gamow Bag
The use of Gamow bag is simple yet requires proper care and attention. First of all place the Gamow bag in a plain space and make sure to check for the sharp objects and edges. The zipper and the window should face straight-up. Now attach the hose or the pipe from the foot pump to the intake valve located in the base by tightly pressing the hose into the valve.
Step 2: Placing the victim
The victim enters the bag through the zipper and rest in sleeping position (just as a sleeping bag). The team should help the victim if he/she is unable to get into the bag. The victim should insert their lower body (feet) to the end of the bag. The victim may use blankets or sleeping bag if the environment is too cold. Now, pull the zip to the end. The victim can help reduce the time of inflating by extending their arms and legs that will enlarge the Gamow bag.
Step 3: Pressuring the Gamow Bag
The air is pressurized through the hand pump, foot pump, or air compressor through the intake valve into the bag. The electrically operated compressor is operated with Schrader valve whereas a 1/4 hp Gast Oil-Less compressor may be attached for continuous venting. It takes about 15 pump strokes per minute (1 pump for every 4 seconds) to deliver the pressure inside the bag. The pump maintains the pressure of about 13789.5 Pa or 2 psi inside the chamber. The bleed valve releases the air if the pressure exceed from that. The steady pumping generates the air flow that delivers enough oxygen for the victim inside and prevents from excessive carbon-dioxide concentration.
Step 4: Discarding the victim
With the help of your finger, lower and turn the internal valve stem of the air inlet to the lock down position. The pressure inside the bag will be released slowly after that. After the bag is fully deflated, open the zipper slowly to the end and remove the victim carefully. After removing the victim, be sure to close the valve stem again.
Things victim should know before entering the Gamow bag:
These are some important things that victim should know or the guide should explain to the victim before entering the Gamow bag:
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The victim should be comfortable and warm inside the bag. The victim can take some appropriate personal things.
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The bag takes about 8 minutes to inflate.
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The victim can extend their arms and legs if they are capable. It will help to inflate the gamow bag faster.
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The trainer or guide will be able to communicate simply through basic hand signs and indication. The victim and the guide can set signs for emergency or for the time of leaving the bag.
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The victim will not have difficulty in breathing inside the bag.
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There will be short and regular stop during the pumping so there is no need to panic.
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The ears of the victim inside may pop due to the rise of the pressure. This is also natural and if that happens, the victim should swallow.
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The guide should and will always communicate with the victim.
Safety and precaution of Gamow Bag:
Some accidents and problems that might occur during the use of Gamow Bag:
These are some serious problems that might occur during the use of Gamow Bag. If any of these is seen, the victim should immediately let the guide know and end the treatment.
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Ear Barotrauma
As discussed above, sometimes ear of the victim may pop during the use of Gamow Bag but the ear-drum of the victim may be affected sometimes due to the rise of pressure. The pain increases as the altitude increases. If further pressure is increased, the ear-drum might break or harmed which is extremely dangerous. To prevent from this, make sure that the victim’s ear canal is not blocked. Other cause might be allergies and infections -
Decompression Sickness (DCS)
Decompression Sickness is the formation of bubbles of inert gases (mainly nitrogen and helium) within tissues of the body due to the reduction of the altitude pressure. -
Pulmonary Hyper expansion
Pulmonary Hyper-expansion can be caused when there is rapid pressure drop, that expands the volume of air in the lungs. The lungs expand if the victim hold their breath at the time of decompression. So the guide should clearly instruct the victim to exhale when there is a fast decompression. -
Excessive Carbon Dioxide Exposure
The carbon-dioxide is concentrated excessively if the fresh air is not pumped enough into the bag. High inhale of CO2 is dangerous for human. If you pump the air as explained above (10-20), then the
carbon dioxide concentration will remain less than 1%.
Things to consider while using/operating Gamow Bag:
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Always detach the hose pump from the chamber first before the foot-pump to prevent the air from escaping.
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The device provides the first aid for altitude sickness; not cure it. If the changes in victim is not seen from the treatment, you should immediately descend the victim to lower altitude.
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This device should only be used by/under a trained person on an emergency situation when medical treatment is not available.
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Use Gamow bag in ambient air environment. Do not use it with enriched oxygen concentrations.
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Do not twist the nylon web straps. They should be in their proper locations during the inflated state.
Conclusion:
Gamow Bag is a significant medical device used in high-altitudes to lower the altitude pressure and treat the altitude illness. You should use the Gamow bag by joining the foot pump to the chamber and pump for 10 to 20 (15 average) times a minute that maintains the pressure of 2 psi. The parts of the Gamow Bag and its function is explained. You can learn to operate and use the Gamow bag by going through the text. There are many things that you need to consider while using the Gamow bag and things that victim should know before the treatment.