Which of the following is a reversible T (to be considered) of cardiac arrest?

• A. Hypoxia
• B. Tamponade
• C. Hypovolemia
• D. Hypothermia

Answer: (B)

The key idea here is the list of reversible causes that can be addressed during resuscitation, specifically the “T” category. Obstructive tamponade fits this because it creates cardiac arrest by compressing the heart and preventing proper filling, which results in very little forward flow despite CPR.

Tamponade is treatable in the moment with pericardiocentesis or surgical drainage to relieve the pressure around the heart. If suspicion is high (for example, in a patient with signs suggesting fluid around the heart or after penetrating trauma, or when point-of-care ultrasound shows a pericardial effusion), decompressing the pericardium can restore ventricular filling and allow return of spontaneous circulation, making it a reversible and actionable cause during resuscitation.

The other options are indeed reversible causes of arrest but they fall under different categories. Hypoxia and hypovolemia are typically managed with better oxygenation/ventilation and fluid or blood resuscitation, respectively, and hypothermia is treated with warming; they’re not the “T” cause in this context, so tamponade is the best fit for a reversible T.