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

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Wilderness and Rescue Medicine

detailed in the basic and advanced life support and the allergy and anaphylaxis chapters. Alveoli The usual problem in the alveoli is fluid accumula- tion blocking the exchange of oxygen and carbon dioxide between air and blood. The generic term for this is pulmonary edema. The source is usu- ally capillary leakage within the lung as part of an inflammatory process caused by infection or inhalation injury. Contusion of lung tissue can also result in pul- monary edema. You should anticipate this condi- tion in patients with suspected rib fracture or any blow to the chest severe enough to “knock the wind out” of them. Capillary leakage can also be the result of congestive heart failure or the effect of reduced oxygen at high altitude. Contusion or laceration of the lung tissue may cause the alveoli to fill with blood. Shortness of breath on exertion will reveal the reduced lung capacity in the early stages of fluid accumulation. The patient often develops a dry cough as the lung tries to clear itself. A low-grade fever may develop. In the presence of a mecha- nism of injury like submersion, high-altitude pul- monary edema, chest trauma, or infection, these early signs are reason to anticipate respiratory distress as the situation becomes worse. As the problem progresses, crackles may be heard with a stethoscope or an ear to the chest as the patient inhales. Large amounts of fluid in the lungs will cause gurgling that can be heard at a distance. Fluid may froth from the mouth and may be tinged with pus or blood. At this point, respiratory distress will have become obvious, with imminent respiratory failure. With alveolar fluid, PROP canmake a significant difference. Positive pressure ventilation can help force alveolar fluid back into the circulatory sys- tem, restoring lung surface area for gas exchange and opening airways. You should not wait for the patient to stop breathing to apply positive pres- sure ventilation (PPV). This is a safe and effec- tive basic life support treatment for respiratory distress. Do not worry about timing; a patient in

trouble will adjust his or her respiratory effort to your efforts to assist. The patient will prefer to sit up, even on a litter during evacuation. Supplemental oxygen will help and should be an early part of the plan for treat- ment and evacuation. Definitive care will require antibiotics for infection or medication to reduce edema from other causes. Access to advanced life support is high priority. For high-altitude pulmo- nary edema, the definitive treatment is immediate descent, but there are medications that can buy the patient some time (see the altitude illness chapter).

General Principles

Fluid in the Alveoli (pulmonary edema)

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MOI: • Swelling (water inhalation, HAPE, trauma)

• Congestive heart failure • Infection (pneumonia) Assessment:

• Crackles, cough, gurgling, respiratory distress • Exposure to inhalation injury, altitude, trauma • History of illness Treatment: • PROP, especially PPV • Treat the cause (medication) • Evacuate to Advanced Life Support

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Chest Wall and Diaphragm Trauma to the chest wall or diaphragm can inter- fere with the function of the respiratory system in several ways, but the most common cause of respi- ratory distress is pain from fractures or sprains. The effective application of PROP and pain relief will often significantly improve the respiratory status of the trauma patient. Sometimes a rib belt or wrap around the chest will make the patient more comfortable if walking or crawling is nec- essary. If you choose to apply a belt, monitor the patient carefully and be prepared to remove the belt if it seems to make breathing worse. More serious structural damage to the chest, or pain that does not respond quickly to field treat- ment, deserves urgent evacuation. An unstable chest wall, also called a flail chest, indicates that the bellows system is damaged to the point that it is no longer rigid. Instead of the lungs expand- ing with inspiration, the chest wall collapses.