NREMT Paramedic

This presentation is most consistent with a tension pneumothorax, suggested by unilateral hyperresonance with markedly decreased breath sounds plus hemodynamic compromise (hypotension), JVD, and tracheal deviation. The immediate, life-saving treatment is needle decompression to rapidly relieve intrathoracic pressure, followed by definitive management (eg, chest tube). CPAP can worsen a tension pneumothorax by increasing intrathoracic pressure. Intravenous corticosteroids and nebulized albuterol may be appropriate for asthma exacerbations, but they do not address the mechanical obstructive shock physiology of a tension pneumothorax and should not delay decompression.

Horizontal ST-segment depression in multiple leads most strongly suggests subendocardial myocardial ischemia, which is classically seen with NSTEMI or unstable angina. An ECG with ST depression supports ischemia but cannot by itself distinguish NSTEMI from unstable angina; that distinction depends on cardiac biomarkers (eg, troponin elevation in NSTEMI). STEMI is typically associated with ST-segment elevation in anatomically contiguous leads (often with reciprocal ST depression elsewhere). Acute pericarditis usually causes diffuse ST elevation with PR-segment depression. Hyperkalemia more commonly produces peaked T waves, PR prolongation, and QRS widening rather than horizontal ST depression.

Abruptio placentae is premature separation of the placenta from the uterine wall and classically presents in the third trimester with painful vaginal bleeding, uterine tenderness/rigidity, and often contractions (and may be associated with fetal distress). Placenta previa typically causes painless vaginal bleeding with a soft, nontender uterus. Spontaneous abortion and ectopic pregnancy are usually early-pregnancy conditions and are unlikely presentations at 34 weeks gestation.