DENVER – Patients with pneumonia may be at risk of sudden cardiovascular collapse within the first 72 hours after admission to the hospital, according to the preliminary findings of a large retrospective analysis.
In addition, almost one in five of those in-hospital cardiac arrests (IHCA) occurred outside of the intensive care unit, and many of the patients were not receiving critical care interventions prior to the cardiac arrest, the study investigators found.
The findings "may indicate that current triage practices or other processes of care are inadequate," the researchers noted (Am. J. Respir. Crit. Care Med. 2011;183:A6339).
The new study is the first of its kind to analyze the characteristics of in-hospital cardiac arrest among pneumonia patients, Dr. Gordon E. Carr, the study’s lead author, said during a briefing at an international conference of the American Thoracic Society.
The sudden and rapid decline in pneumonia patients "is a problem that may happen in 1 in 10 patients but hasn’t received due attention, in part because it’s hard to study," said Dr. Carr, pulmonary and critical care fellow at the University of Chicago Medical Center. "There’s an unmet need to know more about what’s going on with these patients."
More than 1 million patients with pneumonia are admitted to hospitals each year, and 3.4% of in-hospital patient deaths are due to pneumonia, according to national data.
Patients with pneumonia are at risk of following a progressive pathway of severe sepsis, septic shock, and multiple organ failure before having a cardiac arrest, Dr. Carr noted. However, some patients go from developing severe infection straight to cardiopulmonary collapse, without developing severe sepsis or septic shock. Several clinical and epidemiologic studies have shown that not all patients with sepsis go down the typical progressive pathway (Curr. Opin. Anaesthesiol. 2008;21:128-40).
Dr. Carr and his colleagues at the University of Chicago Medical Center conducted the retrospective analysis using the American Heart Association’s Get With The Guidelines Resuscitation database, formerly known as the National Registry of Cardiopulmonary Resuscitation. The data covered 9 years and included 10% of hospitals (approximately 500) in North America.
The team analyzed 166,919 cardiopulmonary arrest events, 44,416 of which occurred within 72 hours after admission. They focused on 5,367 events in which patients had pneumonia as a preexisting condition (12% of the 44,416 events) prior to having their first pulseless event within 72 hours of hospital admission.
The median time from hospital admission to IHCA was 20.7 hours. Only 14.7% of patients with pneumonia and IHCA survived to hospital discharge, according to the analysis. Also, 19.3% of the IHCA events occurred in a general inpatient area, while 77.2% of IHCA events occurred in an intensive care or step-down unit.
At the time of IHCA, 40% of the patients were receiving mechanical ventilation, 12.2% had a central venous catheter in place, and 36.3% were receiving continuous infusions of vasoactive medications.
The analysis showed that arrhythmia was the most common cause of IHCA (65%) among that group of patients, followed by respiratory insufficiency (53.9%), and hypotension/hypoperfusion (49.8%).
In addition, the majority of the rhythms were not "shockable," said Dr. Carr, including pulseless electrical activity (45.2% of cases), asystole (38.4%), and ventricular fibrillation or tachycardia (16.4%).
The study had several limitations, Dr. Carr said. It is based on a large database, and "any huge set of data is going to have the inherent problem in terms of bias," he said. Also, the researchers couldn’t adjust for the severity of pneumonia, and they had no information on the processes of care, such as antibiotic administration.
Given the preliminary nature of the data, it is hard to draw firm conclusions, he noted. However, the study highlights the need for more research on cardiac arrest in pneumonia patients.
The take-away message for physicians is "to be alert to the possibility of abrupt collapse in pneumonia patients," and monitor those patients with comorbidities carefully, Dr. Carr cautioned.
Dr. Carr had no disclosures.