Berg RA, Hilwig RW, Kern KB, Ewy GA Precountershock cardiopulmonary resuscitation improves ventricular fibrillation median frequency and myocardial readiness for successful defibrillation from prolonged ventricular fibrillation: a randomized, controlled swine study. Ann Emerg Med. 2002 Dec;40(6):563-70.
Cummins RO, Ornato JP, Thies WH, Pepe PE Improving survival from sudden cardiac arrest: the "chain of survival" concept. A statement for health professionals from the Advanced Cardiac Life Support Subcommittee and the Emergency Cardiac Care Committee, American Heart Association. Circulation. 1991 May;83(5):1832-47. Review.
Eftestøl T, Sunde K, Steen PA Effects of interrupting precordial compressions on the calculated probability of defibrillation success during out-of-hospital cardiac arrest. Circulation. 2002 May 14;105(19):2270-3.
Halawa B [Treatment of cardiac arrhythmia in pregnant women]. Pol Merkur Lekarski. 2000 Aug;9(50):513-8. Polish.
Hersan O, Jost D, Banville IL et al More CPR With the New Guidelines. Does It Impact VF Termination by Defibrillation Shocks? [abstr]. Circulation 2007;116:II_386-a.
Jost D, Calamai F, Fontaine D et al Concordance Between Carotid Pulse Check and Transthoracic Impedance Characteristics in Out-of-Hospital Cardiac Arrest [abstr]. Circulation 2006;114:II_1201-a.
Renard A, Jost D, Verret C et al Effect of Thrombolytics on the Immediate Prognosis for Out-of-Hospital Cardiac Arrest [abstr]. Circulation 2007;116:II_928-b.
van Alem AP, Sanou BT, Koster RW Interruption of cardiopulmonary resuscitation with the use of the automated external defibrillator in out-of-hospital cardiac arrest. Ann Emerg Med. 2003 Oct;42(4):449-57.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
