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Course Sample:
Glossary of Terms
Atelectasis?an abnormal condition in which lung tissue collapses.
Diffusion?although this refers to a number of functions, as used here, it is the process by which gases move from an area of high concentration to an area of lower concentration.
Hypercarbia?an increased amount of carbon dioxide in the blood (also known as hypercarpnia).
Hypoxemia?insufficient amount of oxygen in the blood.
Sepsis?an infection caused by microorganisms or their poisonous by products in the bloodstream.
Surfactant (pulmonary)?a substance that reduces the surface tension of pulmonary fluids and contributes to the elasticity of pulmonary tissue.
Adult Respiratory Distress Syndrome (ARDS) is a complication that occurs secondary to a patient?s underlying medical condition. Although ARDS is usually diagnosed after the patient has been hospitalized, a patient with ARDS may present to the prehospital care provider as being difficulty breathing or in respiratory distress. Recognition of the possibility of ARDS, coupled with early and aggressive intervention, may prove to be invaluable to these patients?despite a nearly 40 percent mortality rate.
Scenario
A hysterical family member who informs them that his 75-year-old mother is "really sick" greets paramedics responding to a respiratory distress call. On entering the patient?s room, the paramedics see that the patient is sitting upright on her bed and is experiencing dyspnea. Her respiratory rate is approximately 42, and auscultation of her lungs reveals rales in all fields with a slight expiratory wheeze. The paramedics administer high-flow oxygen to the patient via non-rebreather and prepare for further assessment.
One paramedic palpates the patient?s radial pulse and finds it to be tachycardic; her skin is mottled, cool to touch and diaphoretic. Although the patient is alert and able to follow simple commands, she is unable to speak in complete sentences because of her respiratory distress. While one paramedic completes the exam, the other attempts to obtain her past medical history but unable to do so due to the family member?s hysteria.
The first paramedic establishes an intravenous (IV) line of NS (Normal Saline) at a keep open rate. As the IV is being established, the other paramedic reports the following vital signs: blood pressure-170/84; pulse-126; and the EKG reveals a sinus tachycardia. Her neck veins are slightly distended, and she has generalized edema of her extremities. She has no neurological deficits, and her pupils are equal and reactive. Her pulse oximetry is only registering 78% even with the high-flow oxygen. As the paramedic finishes her exam and assessment, the patient?s respirations become increasingly labored. Due to the severity of the patient?s condition, they nasally intubate her with a 7-mm endotracheal (ET) tube. Proper ET tube placement is confirmed by auscultating breath sounds bilaterally in both lung fields, and by the absence of breath sounds in the epigastric area. The patient?s ventilations are then assisted with a bag-valve unit (BVM) with high-flow oxygen.
After contacting medical control, the paramedics receive permission to administer 40-mg furosemide and 4-mg morphine sulfate IV push. They package their patient and transport her to the closest emergency department. During the 10-minute transport, the patient is reassessed. Respirations are now assisted at 28, with auscultation of breath sounds revealing rales only and a pulse oximetry of 92%. Her heart rate is now 120, with the monitor showing sinus tachycardia, and her BP is 164/P. The patient?s skin is pale and mottled but significantly drier. She is still conscious and able to follow simple commands.
At the ED, the hospital staff finds the patient?s condition to be similar to that reported by the paramedics. However, after interviewing the now calmer family members, the staff learns that she had an infection several months ago. Her family was trying to care for her at home, but the patient did not take her medications and refused hospitalization or seeing a doctor. The woman is admitted to the critical care unit, where she is later diagnosed with sepsis. Despite weeks of aggressive critical care, antibiotic administration and specialized tests, the patient?s condition deteriorates. She is subsequently diagnosed as having ARDS and dies three weeks later.
History
ARDS has been a recognized syndrome since the mid-1960s, affecting up to 180,000 people in the United States per year. It has a mortality rate of at least 45% (percent). Definitions of ARDS can vary. Some consider it to be a form of noncardiac pulmonary edema. It can also be described as an adverse condition within the lungs that occurs due to damaged lung tissue. A more graphic description is "shock lung".
Regardless of the various terms used, it is known that multiple events occur when ARDS develops. Unlike cases involving simple injuries or illnesses, ARDS patients have underlying medical conditions, such as pneumonia or sepsis. The presence of the illness along with its complications can create an environment in which ARDS can develop as an additional complication.
Anatomy and Physiology
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