Читать книгу Emergency Medical Services - Группа авторов - Страница 260

EMS clinicians should focus on previous cardiac‐related problems in stable patients. For example, a patient who presents with new‐onset wide‐complex tachydysrhythmia with a history of previous myocardial infarction is much more likely to have VT than a supraventricular rhythm with abnormal conduction. Similarly, one with a history of a previous dysrhythmia who presents with similar symptoms again is likely to have recurrence rather than a new dysrhythmia. Neither of these clinical rules is infallible, but this information can help guide therapy. Other points are also helpful. For instance, a patient with a history of poorly controlled hypertension presenting with a lowered but “normal” blood pressure suggests a dramatic change, prompting treatment that is more intensive.

History can influence the dosing of field agents. Subjects with liver or heart failure, and those aged 65 years and older, should receive lower lidocaine infusions or follow‐up boluses. Those patients with renal failure are at risk for hyperkalemia and rhythm changes. The current medications can provide a clue to any previous conditions or guide field drug therapy. A patient treated with digoxin or a beta‐blocker plus an anticoagulant for palpitations may have atrial fibrillation. Finally, although rare, a brief search for drug allergies or intolerances (“Has any heart drug been bad for you?”) may help avoid a complication. The key is to take a focused history, looking for information regarding heart disease and other specific conditions.