Biomedical subjects
Orlando J Dominguez
Publications and source records attributed to Orlando J Dominguez.
Breathless.
This case presented the scenario of a patient who had severe bronchospasm from an unknown etiology. Further, she had difficulty speaking and denied any past medical history, which made a diagnosis more difficult. Prehospital providers were challenged with determining the differential diagnosis for bronchospasm and hypoxemia. Was the patient experiencing an anaphylactic reaction, acute asthmatic attack or something else? The key here, once again, is conducting a thorough assessment and patient history. Remember, all that wheezes is not asthma; therefore, providers in this case had to determine if the patient was suffering something such as anaphylaxis, asthma, bronchitis, pneumonia or even congestive heart failure (CHF). Typically, anaphylaxis and asthma affect ventilation, not oxygenation, so until the late stages of anaphylaxis or asthma, the patient will have difficulty moving air, but will be oxygenating OK. We understand that many respiratory conditions can cause wheezing, but CHF? Yes: As left ventricular function diminishes and leads to increased pulmonary pressure, serum begins to leak out of the pulmonary vessels and into the interstitial space. As the interstitial pressure increases, it causes narrowing of the bronchioles, and air traveling through the narrowed bronchioles causes the wheezing sound. Fluid may also be leaking out of the pulmonary capillaries and occupying space in the alveolar sacs. When the interstitial pressure is high and the bronchioles continue to narrow, providers may initially hear only the wheezing and not the crackles from the smaller airways. In these conditions, oxygen is not exchanged adequately into the blood, and the patient becomes hypoxemic. Good assessment and patient history will guide the EMS provider to the cause of bronchospasm. For example, does the patient have a history of asthma? If yes, asthma is likely to be the cause. Does the patient have any rash, hives or swelling? If yes, anaphylaxis is likely the cause. Is the patient elderly, and does he/she show pedal edema, JVD, hypoxemia and/or distended neck veins? If yes, CHF may be the cause. [table: see text] There are questions regarding the use of bronchodilators in patients suffering CHF. If a CHF patient is wheezing (bronchospasm), then a beta-2 selective breathing treatment may be appropriate, along with nitrates and diuretics. Oxygenation is the critical problem in CHF, and hypoxemia will continue to worsen cardiac function. Remember, both bronchoconstriction and alveolar sacs filling with fluid will impair oxygenation of the RBCs and ultimately the vital organs. Focused prehospital management of CHF is aggressive in restoring oxygenation. For example, many agencies are now using oxygen, nitrates, ACE inhibitors and CPAP. By better understanding the pathophysiology of respiratory emergencies and their differential diagnosis, we will improve patient outcomes.
Prehospital rounds. The quick stop.
The coroner's post-mortem examination revealed a tom aorta. This case illustrates that although a patient may appear stable, a major catastrophic event may nonetheless be taking place. How many times have we responded to MVAs similar to the one described here and seen those involved deny injuries? We carry a higher suspicion of aortic injury after someone has been ejected from a vehicle or involved in a high-speed crash. That's not always the case, however, and understanding how internal organs respond to high-speed impacts is crucial. Damage to the aorta may result after a sudden deceleration injury of any type: a fall, vehicle crash or violence. The most common forms of traumatic aortic injury occur where the aorta is "tethered" in place: at its intersection with the heart and at its distal portion just beneath the left subclavian artery near the ligamenta arteriosum. Approximately 80% of patients with aortic injury die at the scene. The injury may be hidden in the other 20%, but they have the potential to rapidly deteriorate and die. Those who survive typically are at a trauma center and are cared for by providers who have a suspicion of the injury. A high index of suspicion should be maintained on all rapid-deceleration injuries and with patients who experience chest pain, dyspnea, a difference in pressure between the upper and lower extremities, and paralysis. Paralysis can occur when aortic injury cuts off blood supply [table: see text] to the spinal cord. The spinal cord obtains its blood supply from arteries coming directly off the aorta, and a torn aorta can shear off these vessels, leaving the spinal cord to infarct and the patient to lose all distal function. When a victim sustains a sudden-deceleration injury to the chest, signs of aortic injury should be sought. It is imperative to maintain a high index of suspicion throughout patient care and be aware that although a patient may appear to be quite stable, the reality might be otherwise, and rapid transport to a trauma center will be necessary to save their life.