Cook DJ, Simel DL The Rational Clinical Examination. Does this patient have abnormal central venous pressure? JAMA. 1996 Feb 28;275(8):630-4.
Deol GR, Collett N, Ashby A, Schmidt GA Ultrasound accurately reflects the jugular venous examination but underestimates central venous pressure. Chest. 2011 Jan;139(1):95-100. doi: 10.1378/chest.10-1301. Epub 2010 Aug 26.
Fletcher RH, Fletcher SW Has medicine outgrown physical diagnosis? Ann Intern Med. 1992 Nov 1;117(9):786-7.
Jang T, Aubin C, Naunheim R, Char D Ultrasonography of the internal jugular vein in patients with dyspnea without jugular venous distention on physical examination. Ann Emerg Med. 2004 Aug;44(2):160-8.
Lipton B Estimation of central venous pressure by ultrasound of the internal jugular vein. Am J Emerg Med. 2000 Jul;18(4):432-4.
Mangione S, Nieman LZ Cardiac auscultatory skills of internal medicine and family practice trainees. A comparison of diagnostic proficiency. JAMA. 1997 Sep 3;278(9):717-22. Erratum in: JAMA 1998 May 13;279(18):1444.
Sondergaard S, Parkin G, Aneman A Central venous pressure: we need to bring clinical use into physiological context. Acta Anaesthesiol Scand. 2015 May;59(5):552-60. doi: 10.1111/aas.12490. Epub 2015 Feb 13. Review.
Use of the SonoSite Probe for Measuring Jugular Venous Pressure
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.
