slideústavfyziologie2lfuk.ppt

TABLE OF CONTENTS QUICK DEFINITION OF HYPOXIA SYMPTOMS OF HYPOXIA SIGNS OF HYPOXIA TYPES OF HYPOXIA QUICK DEFINITION OF HYPOXIA INADEQUATE O2 SUPPLY TO THE BODY TISSUES (ENTIRE BODY) OR (LOCALIZED REGION) SYMPTOMS OF HYPOXIA DEPEND ON: RAPIDITY AND SEVERITY OF THE DECREASE OF ARTERIAL Po2 1) FULMINANT hypoxia (Arterial Po220mmHg) (eg.aircraft loses cabin pressure above 30,000 feet and no supplemental O2 available) Occurs in seconds Unconsciousness in 15-20 sec Brain death in 4-5 min 2) ACUTE hypoxia (25mmHgArterial Po240mmHg) (eg.altitudesof 18,000-25,000 feet) Symptoms similar to those of ethyl alcohol(lack of coordination,slowed reflexes,overconfidence) Unconsciousness Coma and death(in minutes to hours) if the regulatory mechanisms of the body are inadequate 3) CHRONIC hypoxia (40mmHgArterial Po260mmHg) (eg.at altitudes of 10,000-18,000 feet for extended periods of time) FOR EXTENDED PERIODS OF TIME!!! Most clinical causes of hypoxia are in these category Symptoms similar to those of severe fatigue DYSPNEA SHORTNESS OF BREATH + RESPIRATORY ARRHYTHMIAS SIGNS OF HYPOXIA 1. Cyanosis (bluish color of tissue) caused by more than 5g of deoxyhemoglobin/dl in capillary blood(or less than 13ml O2 per 100ml of blood) NOT RELIABLE SIGN OF HYPOXIA!!! ANEMIC PATIENTS never develop cyanosis but are extremely hypoxic PATIENTS WITH POLYCYTHEMIA may be cyanotic but they are perfectly oxygenated Tachycardia (peripheral chemoreceptor reflex response to Po2 ) 3. Tachypnea and Hyperpnea