Diving MedicineDiving MedicineLCdr Peter HatfieldLCdr Peter Hatfield

ObjectivesObjectives

BarotraumaBarotraumaDecompression IllnessDecompression IllnessGas ProblemsGas Problems

Putting it togetherPutting it together

1. pre-existing medical condition eg myocardial 1. pre-existing medical condition eg myocardial

infarctioninfarction

2. trauma/drowning/hypothermia2. trauma/drowning/hypothermia

3. Barotrauma3. Barotrauma

4. Decompression Illness4. Decompression Illness

5. Gas Problems5. Gas Problems

BarotraumaBarotrauma

Boyles LawBoyles Law

Volume inversely Volume inversely proportional to proportional to pressure pressure

Gas attempts to contract or expand IAW Boyle’s Law

In closed spaces, gas cannot enter or escape

Therefore, a pressure differential will develop

Squeese or reverse squeese

1. 1. Non pulmonary barotraumaNon pulmonary barotrauma suit/mask squeezesuit/mask squeeze

sinusessinuses

earsears

teethteeth

bowelbowel

2. 2. Pulmonary barotraumaPulmonary barotrauma arterial gas embolismarterial gas embolism

mediastinal emphysemamediastinal emphysema

pneumothoraxpneumothorax

subcutaneous emphysemasubcutaneous emphysema

Suit/mask squeezeSuit/mask squeeze

Ears/SinusesEars/Sinuses

EarsEars

Barotrauma Barotrauma Teeds 0-5Teeds 0-5

Alternobaric vertigoAlternobaric vertigoDraeger EarDraeger EarPerilymphatic fistulaPerilymphatic fistulaFacial BaroparesisFacial Baroparesis

Barotrauma TreatmentBarotrauma Treatment

Middle EarMiddle Ear

Restrict diving until resolved;Restrict diving until resolved;Mild (0-1) 24 to 72 hoursMild (0-1) 24 to 72 hoursModerate (2-3) 1 to 8 daysModerate (2-3) 1 to 8 daysSevere (4-5) may take up to six weeksSevere (4-5) may take up to six weeks

decongestant , +/- antibioticdecongestant , +/- antibiotic

Perilymphatic fistulaPerilymphatic fistula ENT referral – may need surgery ENT referral – may need surgery

Facial BaroparesisFacial Baroparesis need to reverse due to ischemia need to reverse due to ischemia -myringotomy-myringotomy

Dental- fractured tooth/abcessDental- fractured tooth/abcess

Bowel- possible surgical consultBowel- possible surgical consult

On ascent or descentOn ascent or descent

Pulmonary BarotraumaPulmonary Barotrauma

Potential alveolar rupture from 1 msw (3 fsw) water depth

Pulmonary BarotraumaPulmonary Barotrauma

1. Arterial Gas Embolism1. Arterial Gas Embolism

2. Pneumothorax2. Pneumothorax

3. Mediastinal Emphysema3. Mediastinal Emphysema

4. Subcutaneous Emphysema4. Subcutaneous Emphysema

Breath-hold on ascentBreath-hold on ascentPanic, buddy breathing, laryngospasmPanic, buddy breathing, laryngospasm

Local air trapping in lungsLocal air trapping in lungs Obstructive lung disease, scarring/fibrosisObstructive lung disease, scarring/fibrosis

Frequent Change in PressureFrequent Change in Pressure

SymptomsSymptomsRapid onset (less than 5 min)Rapid onset (less than 5 min)Likely on ascentLikely on ascentConscious/LOCConscious/LOCAny neurological symptom/sign (internal carotid most likely)Any neurological symptom/sign (internal carotid most likely)HemoptysisHemoptysisShortness of breathShortness of breathHigh pitched cryHigh pitched cryPleuritic type Chest painPleuritic type Chest painSubcutaneous emphysemaSubcutaneous emphysema

Can co-existCan co-exist

with pneumothorax or mediastinal/subcutaneous with pneumothorax or mediastinal/subcutaneous emphysema emphysema

TreatmentTreatment

ABC sABC s

Lie down, on side if unconsciousLie down, on side if unconscious

Head down only for short time if at allHead down only for short time if at all

Catheterization if unconsciousCatheterization if unconscious

100% oxygen100% oxygen

Transport to nearest RCCTransport to nearest RCC

Maintain 1 ATA ambient pressure if possibleMaintain 1 ATA ambient pressure if possible

Treatment Table 6

0

4 Hours 46 Minutes

20 5 20 5 20 5

30

5 20 5 20 5 20 5 20 5 20 5 20

30

ASCENT RATE: 0.3 m/min (1 ft/min)

DESCENT RATE: 18 m/min (60 ft/min)

09 m(30 ft)

18 m(60 ft)

O2 periods3 at 18 msw (60 fsw)6 at 09 msw (30 fsw)

Time to Tx of A.G.E. and ResponseTime to Tx of A.G.E. and Response

Time to Tx (hrs)

Cases Cured

Cases Not Cured

Percentage Cured

< 1 16 8 67% 1 – 2 13 2 87% 2 – 3 12 4 75% 3 – 4 7 4 64% 4 – 5 3 4 43% > 5 7 9 44%

Total 58 31 65%

Decompression IllnessDecompression Illness

Compressed airCompressed air 79% nitrogen79% nitrogen

20% oxygen20% oxygen

Venous bubbles unlike AGEVenous bubbles unlike AGE

Left/right shunt could become arterial eg patent Left/right shunt could become arterial eg patent foramen ovale foramen ovale

1929 Clark infused 2,000 ml air at 50ml/hour into a 1929 Clark infused 2,000 ml air at 50ml/hour into a dog with no signs of DCIdog with no signs of DCI

Asymptomatic Military divers can be shown to have Asymptomatic Military divers can be shown to have

bubbles (on doppler) after experimental divesbubbles (on doppler) after experimental dives

Deeper/longer divesDeeper/longer dives

Inadequate decompressionInadequate decompression

AgeAge

Fatigue before divingFatigue before diving

Cold during decompressionCold during decompression

Heavy exercise before during or after divingHeavy exercise before during or after diving

Dehydration (alcohol consumption)Dehydration (alcohol consumption)

Infection, medicationInfection, medication

Flying after divingFlying after diving

Rapid decompression at altitudeRapid decompression at altitude

Bubbles cause Blood / bubble interface activates Bubbles cause Blood / bubble interface activates

blood componentsblood components

Body treats the bubble as a foreign object and coats Body treats the bubble as a foreign object and coats

it in proteinit in protein

RBC agglutination, platelet consumption, vascular RBC agglutination, platelet consumption, vascular

permeability, leukocyte activation, etc.permeability, leukocyte activation, etc.

Endothelial injury. Bubbles activate complement Endothelial injury. Bubbles activate complement

system in some individuals. system in some individuals.

Decompression sickness/stress ContinuumDecompression sickness/stress Continuum

No diveNo stress

Death

Severe DCSType II

Mild DCSType I

Decompressionstress withsymptoms

Decompressionstress without

symptoms

Mild SymptomsMild SymptomsFatigueFatigue

Fleeting joint discomfort (niggles)Fleeting joint discomfort (niggles)

Skin itch and erythemaSkin itch and erythema

Joint painJoint pain

LymphaticLymphatic

Skin (cutis marmorata)Skin (cutis marmorata)

Severe SymptomsSevere SymptomsCNS/ SpinalCNS/ Spinal

Labyrinthine (staggers)Labyrinthine (staggers)

Pulmonary (chokes)Pulmonary (chokes)

Time to symptomsTime to symptoms

During decompression During decompression RareRare0-30 min0-30 min 50% 50%30-60 min30-60 min 75%75%1-6 hours1-6 hours 90%90%6-12 hours6-12 hours 95%95%12-24 hours12-24 hours 99%99%

TreatmentTreatment

100 % oxygen 100 % oxygen delivers oxygen to tissuesdelivers oxygen to tissues

nitrogen gradient (elimination)nitrogen gradient (elimination)

IV Ringers/normal salineIV Ringers/normal saline

RCC RCC even if symptoms have resolvedeven if symptoms have resolved

Gas ProblemsGas ProblemsSYMPTOMS AT DEPTHSYMPTOMS AT DEPTH

NitrogenNitrogen

OxygenOxygen

Carbon DioxideCarbon Dioxide

ImpuritiesImpurities

O2 COO2 CO

Partial pressure at 1ATA =.21 0.01 %Partial pressure at 1ATA =.21 0.01 %

At 30m 4ATA =.84 0.04At 30m 4ATA =.84 0.04

At 60m 7ATA =1.47 0.07At 60m 7ATA =1.47 0.07

Oxygen ToxicityOxygen Toxicity

PulmonaryPulmonaryCNS occurs at partial pressure 1.6 ATA O2 70m on airCNS occurs at partial pressure 1.6 ATA O2 70m on air 6m on 100% O26m on 100% O2

CONCON – Convulsion– Convulsion

VV – Visual aberrations– Visual aberrations

EE – Ears, ringing, bells, etc– Ears, ringing, bells, etc..NN – Nausea– Nausea

TT – Twitching of facial muscles– Twitching of facial muscles

II – Irritability, behavior changes– Irritability, behavior changes

DD – Dizziness– Dizziness

Nitrogen narcosisNitrogen narcosis

Martini’s lawMartini’s law -- 1 martini per every 10 m after 20m depth1 martini per every 10 m after 20m depth

Carbon dioxideCarbon dioxide

1-10 % symptoms1-10 % symptoms

Headache, nausea, fatigue, sweating, tachycardiaHeadache, nausea, fatigue, sweating, tachycardia

SOB, confusionSOB, confusion

Putting it TogetherPutting it TogetherHistory - History - most importantmost important

dive buddydive buddy

Where Where did the symptoms start and did the symptoms start and WhenWhen descentdescent bottombottom surface 1) immediatelysurface 1) immediately 2) delayed2) delayedType of diveType of dive

Prexisiting conditionsPrexisiting conditions

Physical exam- Physical exam- ABC s ABC s

neuro examneuro exam

Signs- resolving, static, progressingSigns- resolving, static, progressing

AGE or DCS treatment is the same “4 min neuro”AGE or DCS treatment is the same “4 min neuro”

examplesexamplesCase 1 VertigoCase 1 Vertigo

21 year old diver with cold symptoms, pain in ear on descent.21 year old diver with cold symptoms, pain in ear on descent.

Forced valsalva- sudden ( in water) onset of vertigo, tinnitus, Forced valsalva- sudden ( in water) onset of vertigo, tinnitus, hearing losshearing loss

Barotrauma to ear alternobaric vertigoBarotrauma to ear alternobaric vertigo perilymphatic fistulaperilymphatic fistula

Did he get better on the surfaceDid he get better on the surface

CompareCompare

Diver on air 30m for 25 minutes -no decompression stops. Diver on air 30m for 25 minutes -no decompression stops. Develops vertigo tinnitus hearing loss 30 mins after surfaceDevelops vertigo tinnitus hearing loss 30 mins after surface

Diver on air 10m for 120 minutes Diver on air 10m for 120 minutes

Case 2Case 2

Diver on air 15m after 10 mins at depth Diver on air 15m after 10 mins at depth feels dizzy, headache, nauseafeels dizzy, headache, nausea

Surfaces feels fine after 5 mins O2Surfaces feels fine after 5 mins O2

CO2,CO, anxiety, non diving medical CO2,CO, anxiety, non diving medical conditioncondition

Case 3Case 3

24 yr old diver feels unwell at 30m after 20 24 yr old diver feels unwell at 30m after 20 mins. On surface anxious tingling in the mins. On surface anxious tingling in the face and arms feels fatigued, rapid face and arms feels fatigued, rapid breathingbreathing

Physical normalPhysical normal

Unsure – trial of pressure?Unsure – trial of pressure?

Trial of Pressure/Treatment Table 5

0

09 m(30 ft)

18 m(60 ft)

DESCENT RATE: 18 m/min (60 ft/min)

2 Hours 16 Minutes

ASCENT RATE: 0.3 m/min (1 ft/min)

20 5 20

30

5 20

30

O2 periods2 at 18 msw (60 fsw)1 at 09 msw (30 fsw)

5

Case 4Case 4

Diver on vacation several consecutive Diver on vacation several consecutive days diving. Flying home develops pain in days diving. Flying home develops pain in shoulder.shoulder.

Can calculate “repat” group or wait 24 Can calculate “repat” group or wait 24 hours. Do not dive on a travel dayhours. Do not dive on a travel day

Case 5Case 5

Diver 40m for 30 mins returns to surface Diver 40m for 30 mins returns to surface within 5 mins develops weakness in left within 5 mins develops weakness in left arm, CN VI palsy and ataxiaarm, CN VI palsy and ataxia

?AGE or DCI?AGE or DCI