Podcast
Questions and Answers
Which factor causes a decrease in PaO2 at high altitudes?
Which factor causes a decrease in PaO2 at high altitudes?
What is a common characteristic of heat exhaustion?
What is a common characteristic of heat exhaustion?
Which condition is specifically associated with hypoxia due to diffusion limitation?
Which condition is specifically associated with hypoxia due to diffusion limitation?
Which of the following is typically increased during exercise?
Which of the following is typically increased during exercise?
Signup and view all the answers
What is the primary physiological change associated with altitude sickness?
What is the primary physiological change associated with altitude sickness?
Signup and view all the answers
What is a common result of V/Q mismatch in the lungs?
What is a common result of V/Q mismatch in the lungs?
Signup and view all the answers
Which of the following describes caisson disease?
Which of the following describes caisson disease?
Signup and view all the answers
What happens to 2,3 BPG levels at high altitudes?
What happens to 2,3 BPG levels at high altitudes?
Signup and view all the answers
Study Notes
Environmental Emergencies
-
Altitude Effects: Increased FiO2, decreased Pao2, and hyperventilation lead to respiratory alkalosis.
-
2,3 BPG Increase: Enhances oxygen release from hemoglobin, aiding in adaptation to high altitudes.
-
Pulmonary Vascular Resistance (PVR): Elevated due to hypoxia and vascular constriction.
-
Acute Mountain Sickness: Symptoms include headache, dizziness, and nausea due to rapid ascent in altitude.
-
HAPE (High-Altitude Pulmonary Edema): Characterized by fluid accumulation in lungs; medical interventions include rapid descent and possibly steroid treatment.
-
HACE (High-Altitude Cerebral Edema): Severe neurological impairment requiring immediate descent and hyperbaric oxygen treatment.
-
Hypothermia: Heat cramps arise from electrolyte loss, while heat exhaustion results from dehydration and decreased blood pressure.
-
Heat Stroke: Occurs at temperatures above 40.5°C, leading to altered consciousness and potential multisystem failure.
-
Frostbite: Results from extreme cold exposure; treatment includes gradual rewarming.
Exercise and Diving
- Exercise Effects: Increases heart rate, stroke volume, and pulmonary blood flow, maintaining a uniform V/Q ratio.
- Diving Risks: Includes barotrauma and caisson disease from nitrogen bubbles; slow ascent necessary to prevent decompression sickness.
V/Q Ratio and Hypoxia
-
Hypoxia Definition: Reduced oxygen delivery to tissues due to factors such as cardiac output, hypoxemia, and anemia.
-
Inspired Oxygen Tension (PIo2): Calculated as PIo2 = FiO2 x P - PH2O; altitude affects this relationship with decreased partial pressures.
-
Hypoventilation Mechanisms: Results in increased Paco2 from CNS depression, obesity hypoventilation syndrome, or neuromuscular disorders, diminishing oxygen supply.
-
Diffusion Limitation: Seen in conditions like pulmonary fibrosis, can present with normal or increased A-a gradients.
-
V/Q Mismatch: Normal perfusion with abnormal ventilation, typically seen in conditions like COPD, pulmonary edema, or embolism, leading to hypoxia.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the effects of altitude and hypothermia on human health. This quiz covers acute mountain sickness, high-altitude pulmonary edema, and cerebral edema, as well as heat-related illnesses. Understand the physiological responses and medical interventions critical for survival in extreme environments.
