Aviation Physiology HELICOPTERS

Terminal Objectives  Be familiar with the avoidance, recognition, and treatment of hypoxia/hyperventilation, aviation related trapped gas hazards, and decompression sickness.

Enabling Objectives 1.1Define hypoxia/hyperventilation. 1.2Recall four subjective/objective symptoms of hypoxia. 1.3State the emergency procedures for a suspected case of hypoxia.

Enabling Objectives 1.4State the NATOPS oxygen usage rules. 1.5 State three symptoms of hyperventilation. 1.6State the emergency procedures for a suspected case of hyperventilation.

Enabling Objectives 1.7Recall the causes, symptoms, and treatment of an inflight ear block, inflight sinus block, barodontalgia, and trapped intestinal gas. 1.8Recall methods for avoiding an inflight ear block, inflight sinus block, inflight tooth pain, and trapped gas. 1.9Define decompression sickness ( DCS) 1.10State the situations where DCS is likely to occur.

Enabling Objectives 1.11Distinguish between Type I and Type II DCS. 1.12State the symptoms for Type I and Type II DCS. 1.13State the NATOPS rules regarding scuba diving and flying. 1.14State the emergency treatment for suspected DCS inflight.

AVIATION PHYSIOLOGY HYPOXIA HYPERVENTILATION TRAPPED GAS DECOMPRESSION SICKNESS

Hypoxia

A Condition That Occurs When Insufficient Oxygen Is Supplied To Body Tissues

Causes Of Hypoxia Cabin altitude >10K’ without O2 Loss of cabin pressure (KC-130) Anemia (A/C exhaust, blood donation, smoking, illness) Chemical and Biological Warfare Blood pooling due to prolonged sitting during long flights

TYPES OF HYPOXIA ANEMIC HISTOTOXIC STAGNANT HYPOXIC

ANEMIC HYPOXIA Reduced oxygen carrying capacity of the blood... –TRAUMA –CARBON MONOXIDE –BLOOD DONATION

ANEMIC HYPOXIA Types of toxic substances: –Aspirin –Nitrates –sulfanilamide's Reductions due to conditions that effect red blood cell count: –Sickle cell anemia –Malnutrition –Sepsis

HISTOTOXIC HYPOXIA Reduction in the ability of tissues to utilize oxygen... –ALCOHOL –DRUGS

Stagnant Hypoxia During prolonged mission flights blood may begin to pool in the extremities Pooling increases, vision begins to fade(gray-out). Blackout occurs due to a lack of blood to the brain.

Stagnant Hypoxia  Specific conditions :  Heart failure  Shock  Arterial spasm  Occlusion of blood vessels from tissue edema  Embolus  Thrombus  Plaques  Infarcts

HYPOXIC HYPOXIA A REDUCED AMOUNT OF OXYGEN IN THE INSPIRED GASES …ALTITUDE

HYPOXIC HYPOXIA  Reduction of alveolar O2 tension  Interferes with gas exchange in two areas:  Ventilation  Diffusion Ventilation caused by:  Reduced barometric pressure  Laryngospasm  Severe asthma  Hypoventilation

HYPOXIC HYPOXIA  Reduction of alveolar O2 tension  Interferes with gas exchange in two areas:  Ventilation  Diffusion Diffusion caused by:  Pulmonary edema  pneumothorax  Pulmonary embolism  Embolism  Congenital heart defects

SUBJECTIVE SYMPTOMS Tingling sensation Dizziness Fatigue Air hunger Euphoria Hyperventilation

OBJECTIVE SYMPTOMS Increased breathing rate Cyanosis Confusion Loss of muscular coordination Unconsciousness

HYPOXIA TREATMENT OXYGEN 100% CHECK EQUIPMENT DESCEND COMMUNICATE CONTROL BREATHING

HYPERVENTILATION

Excessive rate and/or depth of breathing resulting in reduced CO 2 levels in the brain

HYPERVENTILATION CAUSES STRESS/ANXIEY HYPOXIA TREATMENT Same as Hypoxia SYPMTOMS Tingling Rapid Breathing Hot/Cold Flashes Visual Impairment Dizziness Muscle Spasms

TRAPPED GAS Site level 10,000 feet 18,000 feet 25,000 feet 43,000 feet EARS SINUSES GASTRO- INTESTINAL TEETH

EAR BLOCK Causes Symptoms Treatment

Ear Block Treatment ( Ascent ) 1.Yawn 2. Chew 3. Swallow 4. Descend

Ear Block Treatment ( Descent ) äValsalva… ä Yawn, Chew, Swallow ä Slow descent rate äPost Flight Ear Block: äCaused by absorbsion of O2 within the middle ear äTREATMENT = Frequent Valsalva

SINUS BLOCK CAUSE SYMPTOMS TREATMENT FRONTALS ETHMOIDS SPHENOID MAXILLARY

Sinus Block Treatment Descend  Stop descent / Level Off  Valsalva  Slow descent

GI Tract Trapped Gas Causes Symptoms Prevention / Treatment

Causes of GI Trapped Gas  Diet (food and drinks)  Illness

Trapped Gas Treatment 1.VENT 2. SLOW ASCENT RATE 3. DESCEND

Barodontalgia  Causes  Symptoms  Treatment

Barodontalgia Treatment  DESCENT  PREVENTION:  “Avoid flying for hours following major dental work”

DECOMPRESSION SICKNESS Aviation DCS Evolved Nitrogen gas in the body often attributed to a decreased atmospheric pressure. - 18K’ Type I (Non-Serious) –Bends –Skin Manifestations Type II (Serious) –Chokes –CNS –Multiple Symptoms

FACTORS AFFECTING DCS Scuba diving Hydration level Repeated exposures Length of time at altitude Rate of ascent Altitude (18,000ft)

TREATMENT OF DCS 100% OXYGEN (If Available) DESCEND IMMOBILIZE SEEK QUALIFIED MEDICAL TREATMENT RECOMPRESSION ?

SUMMARY HYPOXIA HYPERVENTILATION TRAPPED GAS DECOMPRESSION SICKNESS

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