###### Created: 2024-05-21 13:33 ###### Areas & Topics: #medicine #cardiovascular ###### Note Type: #permanent ###### Connected to: [[Adult Advanced Life Support (AALS)]] - There are 12 main reversible causes of PEA which can be remembered as the 7 H's and 5 T's - The H's and T's are important to consider when going through the [[Adult Advanced Life Support (AALS)]] pathway. | **Potential Cause** | **Identification** | **Treatments** | | ---------------------------------- | ------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- | | Hypovolemia | Rapid heart rate and narrow QRS on ECG; other symptoms of low volume | Infusion of normal saline or Ringer’s lactate | | Hypoxia | Slow heart rate | Airway management and effective oxygenation | | Hydrogen ion excess (acidosis) | Low amplitude QRS on the ECG | Hyperventilation; consider sodium bicarbonate bolus | | Hypoglycemia* | Bedside glucose testing | IV bolus of dextrose | | Hypokalemia | Flat T waves and appearance of a U wave on the ECG | IV Magnesium infusion | | Hyperkalemia | Peaked T waves and wide QRS complex on the ECG | Consider calcium chloride, sodium bicarbonate, and an insulin and glucose protocol | | Hypothermia | Typically preceded by exposure to a cold environment | Gradual rewarming | | Tension pneumothorax | Slow heart rate and narrow QRS complexes on the ECG; difficulty breathing | Thoracostomy or needle decompression | | Tamponade (Cardiac | )Rapid heart rate and narrow QRS complexes on the ECG | Pericardiocentesis | | Toxins | Typically will be seen as a prolonged QT interval on the ECG; may see neurological symptoms | Based on the specific toxin | | Thrombosis (pulmonary embolus) | Rapid heart rate with narrow QRS complexes on the ECG | Surgical embolectomy or administration of fibrinolytics | | Thrombosis (myocardial infarction) | ECG will be abnormal based on the location of the infarction | Dependent on extent and age of MI | N.B. Hypoglycaemia is not officially one of the H’s and T’s for adults, but it still can be an important cause of PEA, especially in children. If another reversible cause has not been discovered or if the patient is known to be susceptible to hypoglycaemia (e.g., brittle diabetes, past surreptitious use of insulin) then this potential cause of PEA should be considered. ### Resources Hs and Ts (Reversible Causes of Pulseless Electrical Activity) https://www.aclsmedicaltraining.com/h-and-t/