
Reversible causes for emergent conditions, often remembered by the 4 Hs and 4 Ts mnemonic for cardiac arrest, include issues with oxygen (Hypoxia), blood volume (Hypovolemia), body temperature (Hypo/Hyperthermia), electrolytes (Hypo/Hyperkalemia), hydrogen ion balance (Acidosis), air pressure (Tension Pneumothorax), heart sac (Cardiac Tamponade), drugs (Toxins), and clots (Thrombosis).