Peshawar Medical College NWFP Pakistan Peshawar Medical College

Peshawar Medical College NWFP Pakistan

Peshawar Medical College NWFP Pakistan

Peshawar Medical College NWFP Pakistan

High Altitude Physiology • Altitude Barometric Pres PO 2 • 5000 feet 600 mm. Hg 132 Effects No hypoxia • 10000 523 mm. Hg 110 Mild symptoms of hypoxia • 15000 400 mm. Hg 90 Moderate hypoxia • 20000 349 73 severe hypoxia Highest level for permanent inhabitants • 29628 235 49 Height of Mount Everest Peshawar Medical College NWFP Pakistan

Immediate /Acute effects of Hypoxia • In unacclimitized Person at 10 -12000 feet 1. Drowsiness 2. Lassitude 3. Muscle fatigue 4. Nausea 5. Headache 6. Mental proficiency > Judgment , memory and motor activity > Twitching & Seizures at 18 -20, 000 feet > Coma & death above 23000 feet Peshawar Medical College NWFP Pakistan

Mountain Sickness • Is the condition characterized by adverse effects of hypoxia at high altitude. • Acute mountain sickness • Chronic mountain sickness Peshawar Medical College NWFP Pakistan

Symptoms of Mountain Sickness • GIT. Mostly due to expansion of gases: Painful distention of stomach and intestine Loss of Appetite Nausea, vomiting Respiratory system: Breathlessness- Pulmonary edema due to Hypoxia Peshawar Medical College NWFP Pakistan

Nervous System: – – Headache Depression Disorientation, Irritability, weakness & fatigue- - All CNS symptoms develops due to CEREBRAL EDEMA Peshawar Medical College NWFP Pakistan

Acclimatization • “ Adaptation or Readjustments in the body to high altitude “ - Peshawar Medical College NWFP Pakistan

Changes during Acclimatization: • Changes in blood RBC count increases Packed cell volume increases Hemoglobin content increases. • Changes in CVS Rate and force of contraction of heart increases Cardiac output increases Vascularity increases. Peshawar Medical College NWFP Pakistan

• Changes in Respiratory system Pulmonary ventilation increases Pulmonary hypertension. Diffusing capacity of gases increases. • Changes in tissues Amount of oxidative enzymes increases Increase in number of mitochondria Peshawar Medical College NWFP Pakistan

Chronic mountain sickness • Red cell mass and hematocrit increases exceptionally high. • Pulmonary arterial pressure becomes elevated. • Right side of the heart enlarges. • Peripheral arterial pressure falls • Congestive heart failure • Death Peshawar Medical College NWFP Pakistan

Deep Sea Diving Peshawar Medical College NWFP Pakistan

Pressure at different levels under the sea ONE L ½L ¼L Peshawar Medical College NWFP Pakistan

Pressures after Sudden Decompression Peshawar Medical College NWFP Pakistan

Decompression Sickness, Caisson’s Disease, Dysbarisom • Occurs when a person returns rapidly to sea level after exposure to High Atmospheric Pressure. Peshawar Medical College NWFP Pakistan

Mechanism: after every 33 feet Pressure rises by ONE atmosphere. So high barometric pressure causes compression of gases. O 2 is Utilized & CO 2 is Expired out BUT N 2 is an Inert Gas & highly fat soluble Bubbles out when suddenly decompressed Peshawar Medical College NWFP Pakistan

Symptoms of Decompression Sickness • Are mainly due to escape of N 2 in the form of bubbles: • Severe pain in the tissues particularly in the Joints. • Numbness, tingling or Pricking ( paresthesia) & Itching due to bubbles in myelin sheath. • Temporary Paralysis due to bubbles in Motor Nerves • Muscle Cramps • Bubble in the blood may lead to occlusion of any vessel Nitrogen Norcosis; N 2 has no effects at sea level BUT In deep sea (high Pressure), Norcotic effects starts appearing. Peshawar Medical College NWFP Pakistan

Prevention and Treatment Prevention • Slow Ascent with short stay at regular Intervals. Treatment • Affected person should be recompressed & then should be brought back to the sea level gradually. • Hyperbaric oxygen therapy SCUBA ( Self Contained Underwater Breathing Apparatus) Is used by deep sea divers Peshawar Medical College NWFP Pakistan