Decompression Illness: Recognition and Initial Treatment Michelle Arnesen, PA-C

Decompression Illness Arterial gas embolism (AGE) Decompression sickness (DCS or “the bends”)

What is the first rule of SCUBA diving? Image courtesy of openclipart.org

What is the first rule of SCUBA diving? Always breathe and never hold your breath!

Boyle’s Law PV = k OR P1V1 = P2V2

Boyle’s Law

How does SCUBA work? Pressurized air in the tank is delivered to the diver at ambient pressure through the use of a regulator. Air freely communicates in the diver’s lungs, sinuses, Eustachian tubes and in the artificial air space inside the diver’s mask.

How does SCUBA work? The diver must perform a Valsalva maneuver every few feet during descent to equalize the air pressure in all of these spaces. A slow ascent with continuous breathing generally ensures that the air spaces will be able to equalize naturally.

What is the second rule of SCUBA diving?

What is the second rule of SCUBA diving? Ascend slowly and with control!

Breathing compressed air at depth 21% O2, 79% N2 N2 not used on a cellular level. N2 is absorbed into body tissues in proportion to the surrounding pressure. N2 dissolves back into the bloodstream during ascent.

Breathing compressed air at depth N2 is off-gassed during ascent and at the surface until it returns to normal levels. Repetitive diving (more than 1 dive in 24 hours) causes more and more nitrogen to be absorbed in the tissues.

Breathing compressed air at depth Tissue Nitrogen Saturation

Failure to always breathe and never hold your breath! Arterial Gas Embolism Failure to always breathe and never hold your breath!

Arterial Gas Embolism Pathophysiology Air expands in the lungs, causing alveolar rupture Gas escapes into the pulmonary veins Gas becomes lodged in small vessels Can lead to cerebral arterial gas embolism (CAGE)

Arterial Gas Embolism Risk Factors Uncontrolled ascent (panic) Obstructive lung disease Other lung conditions Can also occur in healthy patients following a “safe” dive profile

Arterial Gas Embolism Signs & Symptoms Dizziness Blurred vision Areas of decreased sensation Chest pain Disorientation Bloody froth from mouth/nose Paralysis Weakness Convulsions Unconsciousness Not breathing Death Usually within minutes of surfacing, but may take 12-24 hours for symptoms to appear!

Decompression Sickness Failure to ascend slowly and with control!

Decompression Sickness Pathophysiology Nitrogen is absorbed in tissues at depth proportional to the ambient pressure. If diver ascends too quickly, N2 gas bubbles come out of solution and become lodged in tissues and vessels. Tissue damage CNS reactions CV/Pulmonary reactions Bubbles in/near joints  pain, spinal flexion  “bends”

Decompression Sickness Risk Factors Repetitive diving Alcohol consumption Dehydration Exercise after diving Cold water diving/strenuous conditions Flying immediately after diving Pushing the limits Can also occur in a healthy diver following a “safe” dive profile

Decompression Sickness Signs & Symptoms Fatigue Itchy skin Pain – joints, muscles Dizziness Ringing in ears Numbness/tingling Paralysis SOB Rash Paralysis/weakness Difficulty urinating AMS Amnesia Tremors Staggering Bloody, frothy sputum Collapse Unconsciousness May take 12-24 hours for symptoms to appear!

DCI History Onset/progression of symptoms Patient Dive computer Dive buddy/divemaster

DCI Rescue Care Oxygen CPR Transport

DCI Exam Head-to-toe Focus on neuro Serial neuro checks

DCI Differential Diagnosis R/O other causes Bloodwork CXR Head CT DCS is a true clinical diagnosis

DCI Treatment 100% O2, IVF/OF Assess urgency Early & severe S/Sx >> Delayed & mild S/Sx Call DAN Emergency Medical line for assistance Symptoms may improve quickly with O2, but may reappear with cessation of O2  don’t delay!

DCI Treatment Hyperbaric/Recompression Chamber ASAP, definitely within 24 hours Patient is re-pressurized while breathing supplemental oxygen and de-pressurized slowly

DCI Prognosis Complete resolution Significant neurological dysfunction Bladder dysfunction Sexual dysfunction Paralysis/weakness Osteonecrosis (DCS) Return to diving/flying in several days to months, maybe never

Summary AGE Failure to always breathe and never hold your breath. Uncontrolled ascent Alveolar rupture causing arterial gas embolism Can be cerebral (CAGE)

Summary DCS Failure to ascend slowly and with control. Quick ascent, pushing the limits Nitrogen bubbles in tissues/vessels Joint pain, tissue damage, CNS reactions

Summary DCI History/Exam Onset/progression of symptoms Get the dive computer Perform serial neuro checks R/O other causes

Summary DCI Treatment 100% O2, IVF/OF Call DAN Transfer to hyperbaric chamber as soon as patient is stable  don’t delay!

What is the first rule of SCUBA diving? Always breathe and never hold your breath!

What is the second rule of SCUBA diving? Ascend slowly and with control!

What are the three rules of emergency DCI care? Image courtesy of openclipart.org

What are the three rules of emergency DCI care? Call DAN O2 Transport to hyperbaric chamber without delay! Image courtesy of openclipart.org

References Divers Alert Network (DAN) www.diversalertnetwork.com Emergency Medical 1-919-684-9111 Non-Emergency Medical 1-919-684-2948 Professional Association of Diving Instructors www.padi.com SCUBA Diving International www.tdisdi.com Powell, Mark. Deco for Divers. Essex: AquaPress Ltd and Mark Powell, 2008. Print.

Michelle Arnesen, PA-C michelle.arnesen@gmail.com 847-334-3208 Thanks for listening! Michelle Arnesen, PA-C michelle.arnesen@gmail.com 847-334-3208