Squeeze Objectives Define squeeze and state the cause. List 4 air spaces of a diver that are subject to squeeze, and describe the golden rule for squeeze prevention. Name and describe one technique for equalizing pressure in the middle ear. Identify the general category of injuries that are most common in scuba diving. Identify the cause for reverse block, at what point during a dive reverse block might occur, and explain one technique for dealing with a reverse block. Describe one incorrect method for dealing with a reverse block.

Definition Pain due to pressure imbalance between diver air spaces and ambient pressure Cause Diver fails to anticipate and properly equalize pressure imbalance which results from change in depth

SQUEEZE aka BAROTRAUM

Golden Rule: Equalize before you feel any discomfort. If you experience any pain or discomfort, –reverse direction until the pain is relieved, –Equalize –resume the ascent or descent as appropriate. Descents should be performed – feet first through the first feet –slowly to allow time to equalize.

Common Sites of Squeeze

Ear Squeeze Indications Discomfort or Pain in ear Remedy Ascend until pain or discomfort is relieved Prevention Equalize early and often Before experiencing discomfort or pain Valsalva technique

Anatomy of the Ear Water should fill the Ear Canal Transferring air through the Eustachian tube you increase the pressure in the Middle ear. Pressure imbalance between the Ear Canal and the Middle = Squeeze.

Mask Squeeze Indications Mask sucking in against your face Remedy Exhale into your mask Mask must cover your nose Prevention Exhale into your mask Mask must cover your nose

Sinus Squeeze Indication Pain in sinus Blood in your mask Remedy End the dive Prevention Dive when healthy Medications?

Hood Squeeze Indications Unable to equalize ears Feel hood push into your ear Remedy Pull hood away from your head to allow water to enter Prevention Allow water into your hood before descent

Tooth Squeeze Indications Pain in jaw Remedy End dive Prevention Automatic if healthy May be confused with sinus squeeze

Reverse Block Indications Pain on ascent Remedy Re-descend if time and air allow Ascend slowly Wiggle jaw Prevention Automatic if healthy

Summary Squeeze aka Barotrauma is easily prevented. Common sites of squeeze include: ears, mask, sinus and hood. Ear injuries are the most common injuries in scuba. Equalize early and often.