Cardiac arrest, cause unspecified

This code signifies the sudden cessation of cardiac mechanical activity, resulting in the absence of effective blood circulation, when the underlying etiology is not documented or determined. It represents a life-threatening emergency where the heart abruptly stops pumping blood, leading to immediate loss of consciousness and cessation of breathing.

Apply this code when the medical record clearly states "cardiac arrest" but provides no further information regarding the cause, such as myocardial infarction, arrhythmia, or trauma. This is typically used in emergency department settings or upon admission when the patient presents in cardiac arrest and the workup to determine the etiology is ongoing or inconclusive.

• Avoid using this code if a specific cause of cardiac arrest is identified and documented (e.g., acute myocardial infarction with cardiac arrest).
• Always sequence this code as the principal diagnosis when it is the reason for the admission, unless another condition is clearly identified as the underlying cause.
• Review the entire medical record, including discharge summaries and autopsy reports, for any mention of the cause before assigning this unspecified code.