Lungs overexpansion in Freediving

First of all, lung overexpansion (LO) injury is very rarely in Freediving. So, don’t be scared. But since it can be a serious trauma better to have a solid understanding of what it is and how to avoid it.

First, let’s have a talk about the structure of the lungs.

Our lungs are sponge-like air-filled organs that transfer air molecules to and from bloodlungs9 cells. The trachea (windpipe) conducts inhaled air into the lungs through bronchi, which then dived into smaller branches (bronchioles), finally becoming microscopic.

The bronchioles eventually end in clusters of very small air sacs called alveoli. In the alveoli, O2 from the air is absorbed into the blood and CO2 (a waste product of metabolism) moves from the blood to the alveoli (and eventually exhaled). This process in the alveoli calls gas exchange.

Lungs are major airspace in our body. We have actually two lungs – a right and left lungs. They are situated within the thoracic cavity of the chest. The right lung is bigger than the left, which shares space in the chest with the heart.

lungs1Lungs are delicate tissues, and can easily be ruptured. If the air flow inside our lungs becomes restricted as you ascend, the expanding air can rapture the delicate alveoli inside the lungs. This can happen without any warning sensations (since the lungs do not sense pain). Chest congestion, scar tissue, lung disease, and damage from smoking can also create air flow restriction and contribute to LO.

 

When you do a scuba course, your instructor going to repeat many times that the main rule of Scuba Diving – never to hold your breath. Why?

When you do scuba diving you breathe compressed air from scuba tanks and your lungs have the same volume at any given depth. This is why if you are even 10 meters deep and make a rapid ascent with breath hold (due to a panic let’s say) your lungs will expand twice from the normal size! Lung tissue can stretch out a little bit, but not twice from its normal size. Which is easy can bring a scuba diver to the risk of lungs barotrauma.

Lungs barotrauma (LB) can be in a few basic forms

  1. Arterial gas embolism – gas from the lungs escapes into the bloodstream (which can lungs2form bubbles and block blood circulation)
  2. Pneumothorax – air enters the space between the lungs, expands and cause lungs to collapse
  3. Mediastinal emphysema – air enters the space between the chest and the lungs, expands and put the pressure on the lung, heart, or blood vessels.
  4. Subcutaneous emphysema – air escapes from the lungs and travels underneath of the skin (most often around the neck), which can result in voice changing, difficulties swallowinglungs4

Common symptoms of LB are

  1. Paralyze, especially on one side of the body
  2. Unconsciousness
  3. Dizziness and confusion
  4. Coughing up blood
  5. Loss of vision
  6. Change in voice
  7. Heavy chest pain and difficulties in breathing

 

Is lung overexpansion can be a problem for Freedivers? Normally it is not. When you freedive, lungs compressed on your way down and re-expand on your way up to the original volume. So, there is no overexpansion.

But let’s have a look at two situations which can have a potential risk of lungs overexpansion injury

  1. BREATHING FROM SCUBA TANK UNDERWATER. Imagine, a Freediver makes a dive to 10 meters. His lungs compressed at this depth almost twice. When he ascends, lungs come back to their normal shape. But what happened if Freediver takes a breath from scuba tank underwater and then ascent? After inhale from scuba tank lungs will expand to its normal size (sea level), but then, on the way up the lungs will expand twice. What about exhaling on the way up? It will defiantly reduce the risk, but not illuminate it (you also have to keep the ascend speed as slow as you can). But to remove the risk – DON’T TAKE AIR FROM SCUBA DIVER UNDERWATER!
  2. By doing packing Freediver will over expand the lungs on the surface (lungs volume is going to be higher than Total Lungs Capacity). Then Freediver dive to the planned depth. During the dive he is going to have MDR (blood shift in particular) which moves a certain amount of blood into the lungs (causing blood vessels around alveoli to expand in size), preventing from crushing. On the way up air starts to expand, and blood vessels still bigger in size. This theoretically can increase the risk of lung overexpansion. The risk is not huge, but do exist. To minimize it, Freedivers who are packing exhale before they reach the surface (which also decrease the risk of BO). So, before you start practicing packing, please ask your self – DO YOU REALLY NEED TO DO IT? Please, keep in mind that packing is a highly advanced technique and should be practiced only by experienced athletes. Are you high experienced Freediver?

 

Treating lung overexpansion injury.

lungs6Symptoms of LO occur immediately and can include difficulty breathing, chest pain, crackling under the skin, unconsciousness or death. First aid must begin immediately while transportation to a medical facility is arranged. 100% O2 should be provided as soon as possible and CPR started if necessary. Ask yourself, do you have CPR skills?

The victim will need treatment in a hyperbaric (pressurized) chamber as soon as possible to shrink the air bubbles, and then slowly decompressed to allow the air to pass out of the body before it expands and interferes with respiration and circulation.

Suspected tension pneumothorax is treated with needle decompression followed by tube lungs7thoracostomy (at the hospital of course). If a smaller pneumothorax is present and there is no sign of hemodynamic or respiratory instability, the pneumothorax may resolve when high-flow 100% O2 is given for 24-48 hrs. If this treatment is ineffective or if a large pneumothorax is present, tube thoracostomy is done.

Computed tomography of the chest is recommending in any case of suspected pulmonary barotrauma in order predicting future fitness to dive

Freediving vs Scuba Diving

DCIM100GOPROFreediving, as a recreational water-based activity (as well as a sport), getting more and more popular. But still, it is far away from other water activities, like for example scuba diving.

There are a lot of myths around Freediving, which stopping people to try it. Or at least confusing.

Let’s try to find out which one is true and which one is not. So, let’s start!

  1. Freedivers can come much closer to the marine life. NOT TRUE. Well, actually it depends. If you compare an experienced Freediver and a beginner level Scuba Diver, then it is true 100%. But if we compare both an experience Scuba Diver and a Freediver, then it is not that simple. As a former scuba instructor, I had a few thousands of dives and I can say that majority of the marine life can come very close to you (reef fish, turtles, stingrays, sharks etc). Less than a half meter. SomeDCIM101GOPROG0154199.JPG people are saying that fish afraid of the bubbles. But why should they be? Fish are afraid of their natural predators and they don’t make bubbles. Fish afraid if you make too much movement and if you are rapidly closing the distance. However, I am willing to accept that some marine life can come close to a Freediver (at least I was told so by other Freedivers).
  2. Freediving is more environments friendly. TRUE. Freediving boat is usually much smaller and requires a smaller engine. And they don’t have compressors. It reduces air and water pollution (as well as noise pollution). All of this makes a difference on our impact on Nature. Also, Freedivers are usually not that close to the corals (especially beginner level), so, fewer chances to damage fragile corals. We are also diving on the reefs less often (mainly we are diving just in the blue).
  3. Freedivers have less equipment. ALMOST TRUE. If you compare Freediving vs Scuba Diving – you will probably think – oh, this is 100% true, but it is not that DCIM102GOPROGOPR3616.JPGsimple again. If we are talking about starting – then for sure it is true! As soon as you have a mask, you can be a Freediver 😉 For scuba, even for absolute beginner level, there is a standard set – BCD, regulator, fins, scuba tank etc. Coming back to Freediving, like I said, in the beginning, you can just invest in the mask and snorkel. But then it will probably be more equipment – weight belt, neck weight, wetsuit, nose clip, safety lanyard, goggles for the swimming pool, float and rope if you want to train with your buddy independently, etc.
  4. Freedivers are leading a healthier lifestyle. TRUE. Some people like to call Scuba Diving sport, which always confuses me. Obviously, it is not. But freediving is. Even if you are not very serious about results. Freediving training combines correct breathing, different relaxation techniques, different physical exercises (in open water, pool, gym etc), as well as mental training. So, yes, if you like to be connected with Nature and stay healthy – Freediving should be your choice.
  5. Freediving is more dangerous. ABSOLUTELY NOT TRUE. Let’s make a line between Freedivers who are properly educated and follow safety rules and someone who has no idea about basic safety rules and just decided that he/she needs to dive deeper or hold the breath longer. Among the first groups, some problems occur, butDCIM100GOPROG0010673. they are not fatal. The second group is just playing Russian roulette. But the same is true for any other activity in our life – you have to follow safety rules. Even for walking. Disagree? Try to walk across a high way! When someone tells that Freedivers are dying regularly, I am always asking where this information is coming from. And there is no answer. Simple because it is not true. So, the bottom line here – follow safety rules and Freediving would be the safest water based activity!
  6. Freediving is a more natural way to be underwater. Well, of course, it is TRUE. We don’t create with the scuba tanks on our back. But we have reflexes which help us to stay underwater longer and dive deeper. Holding the breath for a certain time is natural for us, as well to the other marine mammals.

 

DCIM104GOPROG0549191.So, what would be your choice? Ideally, try both freediving and scuba diving! In my opinion, if you want to explore reef up to 15 meters deep – Freediving is a much better choice. But if you are planning to explore a dive site 25-30 meter deep, then it is easy to do with a scuba tank. If you are interested in underwater photography or videography, then again, having scuba tanks make your life easier. On the other hand, if you want to enjoy to be underwater and also combine it with a healthy lifestyle – Freediving is a better choice.

If you are interested in proper Freediving education click HERE 😉