Gasping After Cardiac Arrest Associated with Improved Survival

By Todd Neale
TUCSON, Ariz.,30 nov 2008- Out-of-hospital cardiac arrest patients who gasp or have labored breathing derive the most survival benefit from immediate chest compressions, a retrospective analysis showed.
Of patients who received compressions from a bystander, those who were gasping were more likely to survive to hospital discharge than those who were not breathing at all (39% versus 9.4%; OR 5.1, 95% CI 2.7 to 9.4), Gordon Ewy, M.D., of the University of Arizona, and colleagues reported online in Circulation: Journal of the American Heart Association.
"Gasping is an indication that the brain is still alive," Dr. Ewy said, "and it tells you that if you start and continue uninterrupted chest compressions, the person has a high chance of surviving."
Witnesses to cardiac arrest sometimes interpret gasping as normal breathing and don't call 911 or start chest compressions as quickly as they should, according to the researchers.
"These results suggest that the recognition and importance of gasping should be taught to bystanders and emergency medical dispatchers so as not to dissuade them from initiating prompt resuscitation efforts when appropriate," the researchers said.
This is especially important because chest compressions may cause a patient to begin gasping, Dr. Ewy said.
"This scares many people and they stop pressing on the chest," he said. "This is bad because gasping is an indication that you're doing a good job."
To determine the occurrence of gasping after out-of-hospital cardiac arrest, the researchers examined transcripts from the Phoenix Fire Department Regional Dispatch Center.
Of 113 patients who had a witnessed or non-witnessed cardiac arrest, 38.9% gasped or had labored breathing.
In a separate analysis, the researchers looked at emergency medical services' first-care reports of 1,218 patients who had a witnessed cardiac arrest.
Overall, 191 gasped and 1,027 didn't. The two groups did not differ significantly by age, arrest location, or receipt of bystander CPR.
For those who collapsed after EMS personnel arrived, 32.8% started gasping.
Rates of gasping declined as arrival time increased. There were 20.1% who had labored breathing when the arrival time was less than seven minutes, 13.9% when it was seven to nine minutes, and 7.4% when it was greater than nine minutes.
Gasping was significantly more common in the witnessed ventricular fibrillation group than in patients who had a witnessed arrest with a different rhythm (18.4% versus 13.6%; OR 1.7, 95% CI 1.2 to 2.4).
Survival to hospital discharge was significantly higher in patients who had some residual breathing than in those who did not (28.3% versus 7.8%; OR 3.4, 95% CI 2.2 to 5.2).
Of patients who were gasping when EMS personnel arrived, those who were receiving chest compressions from a bystander were more likely to survive than those who were not (39% versus 21%, P<0.01).
Patients who had gasping or labored breathing still had a survival advantage even if they weren't receiving CPR from a bystander (21.1% versus 6.7%; OR 2.4, 95% CI 1.2 to 4.3).
The researchers said that the results call into question the importance of rescue breathing for cardiac arrest patients, especially in light of previous findings of no survival benefit from rescue breathing.
"Interruptions for rescue breathing make CPR efforts more complicated and result in fewer compressions during this crucial period when perfusion is key to successful resuscitation," they said.
In addition, gasping is likely more beneficial than rescue breathing, Dr. Ewy said.
"When the patient gasps, there is a negative pressure in the chest, which not only sucks air into the lungs but also draws blood back to the heart," he explained.
"In contrast, mouth-to-mouth breathing creates overpressure in the chest and actually inhibits blood flow back to the heart," he continued. "Gasping during cardiac arrest is much better than mouth-to-mouth breathing."
The authors acknowledged that the study was limited by the possibility that the EMS reports did not accurately record the presence or absence of gasping.
In addition, they said, gasping is not diagnostic of ventricular fibrillation arrest.
Dr Bobrow has received salary support from the Arizona Department of Health Services via the Mayo Clinic Foundation for support of his position as medical director of the Bureau of Emergency Medical Services and Trauma System. Dr Ewy is a co-investigator on an unrestricted grant from the Laerdal Foundation of Stavanger, Norway, and on unrestricted grants to the University of Arizona Foundation. The other authors reported potential conflicts of interest with the Anaesthesieverein of the Department of Anesthesia and Intensive Care of University Hospital in Basel, Switzerland, the Laerdal Foundation, the National Heart, Lung, and Blood Institute, Medtronic, the AHA National Registry of CPR, Zoll, and PhysioControlInc.
Primary source: Circulation: Journal of the American Heart AssociationSource reference:Bobrow B, et al "Gasping during cardiac arrest in humans is frequent and associated with improved survival" Circulation 2008; DOI: 10.1161/CIRCULATIONAHA.108.799940. Additional Coronary Artery Disease Coverage