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Friday, September 24, 2010

This is worth the read.

Bystander CPR With and Without Rescue Breathing

William T. Basco, Jr., MD

Posted: 09/24/2010

CPR With Chest Compression Alone or With Rescue Breathing

Rea TD, Fahrenbruch C, Culley L, et al
N Engl J Med. 2010;363:423-433

Study Summary

Studies have shown that bystander cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest can improve outcomes, and CPR protocols are continuously being revised in efforts to improve outcomes and simplify delivery of emergency care. Rea and colleagues note that some animal studies have suggested that compression alone can produce outcomes equal to compression plus rescue breathing, and this study aimed to apply that approach to human victims in the field.

Three municipalities or counties participated in the trial, 2 in the United States, and 1 in Great Britain. The study was conducted from 2004-2009. When bystanders called emergency dispatchers, the dispatchers determined whether the patient was eligible for 1:1 random assignment to compression alone or to combined CPR (compression plus rescue breathing). Eligible arrest patients were all out-of-hospital; were not undergoing CPR at the time of the phone call to dispatchers; had not had trauma, drowning, or asphyxiation; and were at least 18 years of age. Postintervention review and exclusion were also conducted -- patients were excluded if emergency medical services (EMS) personnel found them not to require resuscitation or if they were considered to have irreversible death at the time resuscitation was begun.

Dispatchers randomly assigned eligible patients to one of the groups, and instructions to the bystanders were given according to group assignment. The chest compression cycle consisted of 50 compressions. The cycle for the compression plus rescue breathing included 2 rescue breaths, followed by 15 compressions. The outcome of interest was survival to discharge from the hospital.

Approximately one third of the potential participants met eligibility criteria, with 981 analyzed in the compression-alone group and 960 in the combined-CPR group. Mean patient age was 63 years, and approximately two thirds were men. About 72% of the patients had arrest from cardiac causes and 7% from respiratory causes; 43% of the episodes were witnessed. The average time to EMS response was 6.5 minutes. Approximately one third of patients had a shockable rhythm when evaluated by EMS personnel. The patients assigned to compression alone were more likely to receive chest compression (80.5% vs 72.7%, P < .001). In the primary comparison, no difference between survival to hospital discharge between the 2 groups was found (12.5% for compression alone vs 11% for compression plus rescue breathing; absolute difference, 1.5%; 95% confidence interval [CI], 1.4%-4.4%). Discharge without severe cerebral disability was 14.4% among patients who received compression alone and 11.5% among patients who received compression plus rescue breathing, but this difference did not reach statistical significance (P = .13). Subgroup analyses suggested that patients with cardiac arrest fared better with compression alone, whereas patients with respiratory causes of arrest did better with compression plus rescue breathing, but again, the differences were not statistically significant. The investigators concluded that bystander resuscitation with compression alone did not increase overall survival rate relative to bystander compression plus rescue breathing.

Compression-Only CPR or Standard CPR in Out-of-Hospital Cardiac Arrest

Svensson L, Bohm K, Castrèn M, et al
N Engl J Med. 2010;363:434-44

What's with Commotio Cordis?

When someone gets hit hard in the chest in the area of the heart, cardiac arrest can result. This is one source of cardiac arrest in young athletes. Only about a quarter of these victims survive. Those that do survive are associated with immediate CPR and prompt defibrillation. Congenital defects can also cause these events.

Key points:
  • Ask your doctor about a though review of your child's heart before permitting that child to participate in sports where being struct in the chest hard is a possibility or where a congenital defect might cause a problem under conditions where high levels of exertion might be encountered.
  • Make sure that the trainer or coach that is present for all practices and games is trained in CPR and AED use.
  • Make sure that there is an AED on hand at all practices and games. Don't accept an answer of "We only take the AED to games, not practices."
Newspaper reports of young athletes going into cardiac arrest are becoming more common. One of several possible reasons for these arrests is 'commotio cordis' a condition that results from an impact on the chest wall in the area of the heart during a specific part of the heartbeat. (30-40 ms before the peak of the T-wave.)

Such an impact can cause a premature ventricular depolarization, leading to ventricular fibrillation, and subsequently, cardiac arrest. (see Link MS, Maron BJ, Wang PJ, et al. Upper and lower limits of vulnerability to sudden arrhythmic death with chest-wall impact (commotio cordis). J Am Coll Cardiol. Jan 1 2003;41(1):99-104.}

Some other possible causes of these tragic events are congenital abnormalities such as enlarged heart, abnormal structure of the coronary arteries, and longer than normal time between the Q-wave and the T-wave,

About one quarter of these stricken athletes survive to discharge with major brain function intact. (see Maron, BJ: Clinical Features of Commotio Cordis. Presentation of Registry Data at Heart Rhythm Society Scientific Sessions [database online]. Boston, Massachusetts: May 15, 2009.)

Although commotio cordis usually involves impact from a baseball, it has also been reported during hockey, softball, lacrosse, karate, and other sports activities in which a relatively hard and compact projectile or bodily contact caused impact to the person's precordium. (teven M Yabek, MD, FAAP, FACC, Pediatrix Cardiology Associates of New Mexico (a Division of Mednax Medical Group), Presbyterian Hospital Medical Center)