Pulmonary Overpressure

It is a very severe barotrauma, which happens if the air contained in the lungs becomes blocked or is not expelled in sufficient quantity during the ascent. In any of these situations, the air contained in the pulmonary alveoles, when expanding during the ascent, due to decreased pressure, causes a dilation of the alveoles that can cause injuries ranging from simple distension to alveolar rupture.

In the most severe cases there may even be pneumothorax (air penetration into the pleural cavity).

The severity of this accident depends on two factors:

The amount of air the diver has in his lungs at the beginning of the climb
Rapid air expansion at the beginning of the accident

This means that the accident will be all the more serious the greater the amount of air inspired, the faster the climb and the closer the diver is to the surface.

THIS ACCIDENT MAY OCCUR DURING PRACTICAL LESSONS IN SWIMMING POOL, IF THE STUDENT BLOCKS THE EXPIRATION WHEN COMING TO THE SURFACE

If I Have to Return to the Surface?

If you have to return to the surface without being able to breathe through the regulator, you must continuously produce the sound from the beginning of the ascent ! Aaaaaaah! This will be enough to keep the air outlet from the lungs open, while releasing excess air due to increased volume.

NEVER LOCK EXPIRATION DURING ASCENT

Situations to be paid for

Ballast System: It is very important that the diver pays attention to the ballast system and that he is well trained in the use of the diving vest.
Buoyancy Control: It is very important that the diver can control its static buoyancy, in displacement, on the ascents and descents.
Diver in Apnea: Pulmonary overpressure can also occur when an apnea diver receives air at the bottom, returning to the surface with his breathing blocked. That’s why a scaffolding diver should never give air to a diver in apnea.

THIS BAROTRAUMA ONLY TAKES PLACE ON THE RISE

DIAGNOSIS

The diagnosis of pulmonary overpressure should be made whenever the scaffolding diver suffers a loss of knowledge during the ascent or shortly after the exit of the water.

In this case it is natural that other problems are present, as loss of consciousness can also be caused by:

Anoxia (absence of _O2)
Hyperoxia (excess _O2)
Carbon dioxide or carbon monoxide poisoning
Decompression accidents
Pre-drowning

Acting immediately is the principle that should be present in these situations. That is, first, resources must be mobilized to combat shock and respiratory failure and then face the differential diagnosis, to be carried out by the doctor. All these procedures are trained in the CMAS Oxygen Administration course.

The most indicated first aid is the administration of 100% oxygen with a flow of 15l/min, and the injured should be placed in a comfortable position

SIGNS AND SYMPTOMS

Acute chest pain, usually behind the sternum.
Difficulty and exacerbation of pain when breathing.
Cough with blood sputum.
Feeling of chest fullness (full chest).
Swelling in the neck, which on local palpation resembles snow palpation (crackling).
Change in voice tone.
Cyanosis of the lips.
Decreased movements on the side of the affected thorax.
Deflection of the trachea to the affected side.
Neurological changes such as: Mental confusion, difficulty speaking, changes in vertigo sensitivity – convulsions – loss of consciousness.