Which of the following is categorized as a T cause in the H's & T's framework?

• A. Hydrogen Ion (Acidosis)
• B. Hypovolemia
• C. Hypoxia
• D. Tamponade (Cardiac)

Answer: (D)

In the Hs and Ts framework, the T category covers conditions that can cause cardiac arrest but are potentially reversible with prompt treatment. Tamponade (cardiac) is a classic T cause because fluid or blood in the pericardial sac compresses the heart, especially during diastole, preventing proper filling (decreased preload) and sharply reducing cardiac output. This mechanical obstruction means that even with chest compressions, the heart can’t adequately fill and pump, so relief of the tamponade is essential—typically via pericardiocentesis or surgical drainage—alongside resuscitation. The other options fall into the H group: hydrogen ion reflects acidosis, hypovolemia is low blood volume, and hypoxia is insufficient oxygen, none of which are the T-type causes.