Cause Analysis of Non-Traumatic Out-of-Hospital Cardiac Arrest in the Elderly

Abstract

There have been many studies of the resuscitation of non-traumatic out-of-hospital cardiac arrest (NTOHCA) in elderly patients; however, these have tended to focus on the outcomes and predictors of survival rather than on the causes. The purpose of this study was to investigate the leading causes of NTOHCA in the elderly. This was a retrospective study of 330 patients admitted to the emergency department (ED) of Mackay Memorial Hospital in Taipei between January 1 and December 31, 2005 because of NTOHCA. Of the 330 NTOHCA patients, 31 were excluded because resuscitation in the ED was discontinued. Of the remaining 299, 198 were elderly patients aged over 65 years and 101 patients ranged in age from 18–64 years. The causes of NTOHCA were divided into eleven categories, including malignant neoplasm, neurologic disease, cardiovascular disease, diabetes mellitus, pulmonary disease, gastrointestinal system disease, renal and urinary system disease, sepsis, electrolyte imbalance, unknown causes, and other causes. Patients were defined as survivors if they survived to hospital discharge. The overall survival rate of study participants was 7.4%. The survival rate was 6.1% for the elderly group and 9.9% for the younger group. There was no significant difference between the elderly and adult groups ( p = 0.229). The first three leading causes of NTOHCA in the study were cardiovascular disease, unknown origin, and pulmonary disease. Comparing the elderly group and the adult group, elderly patients had significant more pulmonary causes of NTOHCA (17.7% vs. 7.9%; p = 0.008) and a larger proportion of NTOHCA with more than one cause (34.3% vs. 18.8%; p = 0.007). None of the elderly patients whose NTOHCA were attributed to unknown causes, diabetes mellitus, gastrointestinal system disease or malignant neoplasm survived to discharge. In this study, cardiovascular disease was found to be the leading cause of NTOHCA in both elderly and adult patients. The NTOHCA of elderly patients was due to pulmonary causes significantly more frequently than those of the adult group.