Which of the following is NOT included in the Hs and Ts of ACLS?

• A. Hypoxia
• B. Tamponade
• C. Hyperthermia
• D. Thrombosis

Answer: (C)

Hs and Ts guide you to reversible causes of cardiac arrest to address during ACLS. Hypoxia is a primary concern, because a lack of oxygen precipitates arrest and must be corrected. Tamponade describes fluid around the heart that restricts its filling, a situation you treat by relieving the pressure if possible. Thrombosis covers clot-related events such as a coronary thrombosis or a massive pulmonary embolism causing arrest, addressed with reperfusion or thrombolysis when appropriate. Hyperthermia is not part of this mnemonic; the thermal-related issue included is hypothermia, not hyperthermia. Hyperthermia is a separate clinical problem that requires cooling and other supportive measures outside the standard Hs and Ts list.