How to perform a Deep Diver Rescue

February 18th, 2020

All unconscious divers, unless they fortuitously still have their regulators in their mouths and are actively exhaling gas bubbles, must be presumed to have attempted to breathe under water and have inhaled water. The moment water is inhaled, the vocal cords in the larynx contract together, closing the larynx and sealing off the lungs. More water cannot enter, but lung air can also not leave. This is called laryngospasm.

All unconscious divers disconnected from their air supply have laryngospasm and their airways are totally obstructed. They cannot inhale or exhale at all. Attempting to restore breathing by shoving a regulator into their mouths and pressing the purge button is totally futile. No air will reach the lungs. It will simply bubble from the mouth. If they are then rescued and brought to the surface, expanding air trapped in the chest will burst and shred the lungs, and they will die of massive pulmonary barotrauma of ascent.

The same applies to a convulsing diver. During a convulsion, the diver is not breathing, the jaws are clenched and if the mouthpiece is bitten through or free in the water, the first inhalation after the convulsion passes will cause water inhalation and immediate laryngospasm. It is essential to wait for laryngospasm to pass before initiating the rescue ascent.

The problem is that relaxation of laryngospasm only occurs shortly before brain death. At this stage, a near-drowned diver will not even attempt to inhale during a rescue. This means that saving an unconscious diver requires urgent action only in the perilously short time corridor between relaxation of laryngospasm and death. The rescuer must understand this and resist the natural instinct which will prompt an immediate and fatal rescue ascent.

Method

Under water

Ditch the diver’s weight belt.
Wait until any convulsions stop (they always will).
Turn the diver’s head to one side.
Clear the mouth of any foreign material by sweeping your forefinger around the diver’s mouth from cheek to cheek. Do not worry about water entering the mouth − this already happened and caused laryngospasm when the diver tried to breathe under water.
If the diver's regulator is functional and you are confident about the diver's gas supply, replace it into the diver's mouth and hold it there with one hand. Otherwise, use your octopus regulator. This may assist if the diver tries to breathe during the rescue ascent. Air will then be inhaled, not water.
Ascend 2 m or 3 m, holding the diver upright and the hand holding the regulator keeping the diver's jaw well up. Keeping the diver’s neck extended will allow the expanding lung air to vent freely from the mouth during the ascent. Water will not enter the airway under these conditions. If air does not vent and the airway is clear, laryngospasm is still present. Stop and wait for it to pass before continuing the ascent – expanding air will then bubble freely from the mouth and drive most of the water in the mouth and throat out of the regulator.
Do not attempt buddy breathing with a semi-conscious diver.
Perform a controlled emergency ascent. Breathe normally on your rig and ensure free exhalation by the diver. Be careful that any expanding air in your (or the victim’s) BC does not initiate an uncontrolled buoyant ascent.

At the surface

Inflate the diver’s BC and signal for help.
Check that the diver is breathing. If no breathing is evident, begin rescue breathing.
Rescue the diver from the water, with stops for rescue breathing every 15 seconds. If you see help is on the way, stay where you are and give continuous rescue breathing.
On land or on the boat, lay the diver flat and face down. Straddle the diver’s hips and turn the head to one side. Lift the pelvis to drain any water from the airway.
If the diver is breathing, place him or her in the unconscious left lateral rescue position.
If no breathing is evident, roll the diver on to his or her back and begin mouth-to-mouth rescue breathing or commence CPR if no heartbeat or carotid arterial pulse is found. If available, 100% oxygen should be administered.
Summon an emergency rescue service urgently.
Do not forget about any missed decompression stops! If these have occurred, begin pure oxygen breathing yourself and urgently notify a diving physician about the event.