The chest contains the primary organs of circulation and breathing, and thus a thorough assessment of the chest can provide clues to a host of clinical conditions. While the definitive examination of the chest consists primarily of radiographic studies, the physical exam techniques of thoracic assessment are easily mastered by all levels of EMS providers.
Hank is a 64-year-old male who has suffered a persistent cough for the past 72 hours. He slept poorly last night and began to complain of chest pain and dyspnea early this morning, prompting his wife to call 9-1-1.
The responding EMS crew finds Hank sitting on the edge of the bed, coughing frequently and grimacing in pain with every cough. Audible rhonchi can be heard from across the room, and Hank tells the EMTs, “You gotta help me. I can barely catch my breath, and every time I cough it feels like someone is sticking a knife between my ribs.”
While one medic obtains vital signs and an EKG, her partner questions Hank about his medical history. He has a history of CHF, asthma and hypertension, and had an MI followed by placement of two coronary stents six years ago. Noting the ashtray sitting on the bedside table, the medic asks him about his smoking habit, and he defensively claims, “I’ve cut way back. When I had my heart attack, I was smoking 2½ packs a day, and now I’m smoking only one.”
His medications are furosemide, potassium chloride, lisinopril, Plavix, aspirin and sublingual nitroglycerin. He says he’s been taking his medications as prescribed, and took three nitroglycerin tablets and an extra baby aspirin without relief prior to calling 9-1-1.
His skin feels moist and hot to the touch, and vital signs are BP 106/94; heart rate 116 and regular; respirations 28 and slightly labored, with scattered wheezes bilaterally and coarse rales over the left lung fields. The EKG rhythm is sinus tachycardia with occasional PACs, and SpO2 is 89% on room air.
Anatomy and Physiology
The chest cavity is lined by a two-layered membrane called the pleura. The parietal pleura lines the chest cavity itself, and like all parietal cavity membranes is richly supplied with somatic sensory nerve fibers. The visceral pleura covers the lungs themselves and is much less richly supplied with sensory nerves. In normal physiology, the space between the two layers is a potential space only, and they are held in close proximity to each other via surface tension provided by pleural fluid, allowing the lungs to expand along with the rib cage during inhalation. This pleural fluid also provides lubrication between the two layers.
The area in the chest containing the heart, vena cavae and aorta, distal end of the trachea and mainstem bronchi is known as the mediastinum and lies in the center of the chest, directly behind the sternum. Within the mediastinum is also found the hilum of the lungs, the point at which the bronchi, pulmonary arteries and veins, lymphatic vessels and nerves enter each lung. The heart itself is covered with a tough, inelastic membrane called the pericardium and is suspended in the chest cavity by the ligamentum arteriosum, which is formed from the remnants of the ductus arteriosus that was present during fetal circulation.
While her partner administers oxygen and obtains a 12-lead EKG, the paramedic continues her line of questioning, asking Hank about the quality of his chest pain. He says the pain has gradually increased over the past 24 hours, describes it as “stabbing,” and says it worsens dramatically with a cough or deep inhalation. The pain does not radiate and is confined to an area over his left lateral chest. He says it’s different in character from the chest pain he experienced during his MI. He reports a 101.3ºF fever and fatigue, but denies weakness, dizziness, nausea and vomiting.