Wilderness and Rescue Medicine 7th Edition Jeffrey Isaac, PA-C and David E. Johnson, MD

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Section I: General Principles

Chapter 1 Review: General Principles of Physiology and Pathology

• Anything that interferes with the oxygenation and perfusion of a critical system is potentially life threatening. • Shock is inadequate perfusion due to inadequate perfusion pressure in the circulatory system. • Respiratory failure is inadequate oxygenation of the blood due to a respiratory system problem. • Brain failure can be a primary problem causing inadequate circulatory or respiratory control, or a symptom of shock or respiratory failure. • Altered mental status is often the earliest vital sign change when oxygenation and perfusion are impaired. • Swelling is a common cause of problems with oxygenation and perfusion. Anticipating and control- ling swelling are important parts of emergency medical care. • Ischemia is local loss of perfusion due to swelling, deformity, or obstruction. Ischemia that is not corrected will result in infarction. • A serious critical system problem that cannot be corrected will become an emergency. • Obstruction of a hollow organ due to swelling, deformity, or mass will result in infection. • Most people live. There will be situations where good basic medical care on scene offers a better chance for survival than a high-risk rescue.