Hypoxia AHF 2203 Puan Rosdalila Roslan

Gases of the atmosphere

Standard Pressure/Temp With The Increase Of Altitude Altitude (ft)Pressure (mm/Hg)Temperature ( o C) , , , ,

Definition Hypoxia means "reduced oxygen" or "not enough oxygen“. Most concern is with getting enough oxygen to the brain. Any reduction in mental function while flying can result in life-threatening errors.

Causes Hypoxia can be caused by several factors including: a)insufficient supply of oxygen, b)inadequate transportation of oxygen, or c)the inability of the body tissues to use oxygen.

Forms of Hypoxia hypoxic hypoxia hypemic hypoxia stagnant hypoxia histotoxic hypoxia

Hypoxic hypoxia is a result of insufficient oxygen available to the lungs. Although the percentage of oxygen in the atmosphere is constant, but pressure decreases proportionately as atmospheric pressure decreases. This situation leads to only fewer molecules available at the pressure required for them to pass between the membranes in the respiratory system.

Reduced pO 2 in the lungs (high altitude) Body tissue Red blood cells Hypoxic Hypoxia A deficiency in Alveolar oxygen exchange

This occurs when the blood is not able to take up and transport a sufficient amount of oxygen to the cells in the body. Hypemic means "not enough blood." This type of hypoxia is a result of oxygen deficiency in the blood, rather than a lack of inhaled oxygen, and can be caused by a variety of factors.

An oxygen deficiency due to reduction in the oxygen carrying capacity of the blood Hypemic Hypoxia Low- Haemoglobin

Stagnant hypoxia results when the oxygen-rich blood in the lungs isn't moving, for one reason or another, to the tissues that need it. An arm or leg going to sleep because the blood flow has accidentally been shut off is one form of stagnant hypoxia. This kind of hypoxia can also result from shock, the heart failing to pump blood effectively, or a constricted artery.

Causes: During flight, stagnant hypoxia can occur when pulling excessive positive Gs. Cold temperatures also can reduce circulation and decrease the blood supplied.

Reduced blood flow Blood moving slowly Adequate oxygen Red blood cells not replenishing tissue needs fast enough Stagnant Hypoxia G-Forces

The inability of the cells to effectively use oxygen is defined as histotoxic hypoxia. In this case, plenty of oxygen is being transported to the cells that need it, but they are unable to make use of it.

Causes: This impairment of cellular respiration can be caused by alcohol and other drugs, such as narcotics and poisons. Research has shown that drinking one ounce of alcohol can equate to about an additional 2,000 feet of physiological altitude.

Red blood cells retain oxygen Inability of the cell to accept or use oxygen Poisoned tissue Adequate oxygen Histotoxic Hypoxia Alcohol

The common symptoms of hypoxia: Cyanosis (blue fingernails and lips) Headache Decreased reaction time Impaired judgment Euphoria Visual impairment Drowsiness Light-headed or dizzy sensation Tingling in fingers and toes Numbness As altitude increases above 10,000 feet, the symptoms of hypoxia increase in severity, and the time of useful consciousness rapidly decreases.

Symptomology & Altitude Frequency of Occurrence 5,000 ft10,000 ft15,000 ft18,000 ft Blurred visionHyperventilationBelligerenceCyanosis Tunnel visionImpaired task management EuphoriaConfusion Decreased night vision Air hungerSleepinessPoor judgment ApprehensionSlow thinkingMuscle coordination Fatigue Headache Dizziness Numbness / Tingling

Avoid alcohol and smoking Healthy Diet Good physical condition Lower altitudes Avoid temperature extremes Slower Climb rates

Immediately use supplemental oxygen ▫System on, Mask on, breathe normally Check operation of oxygen equipment ▫Don’t wait for problems Make emergency descent if oxygen is not available

Part Supplemental OxygenPart Supplemental Oxygen