Edwards C, Leira EC, Gonzalez-Alegre P Residency training: a failed lumbar puncture is more about obesity than lack of ability. Neurology. 2015 Mar 10;84(10):e69-72. doi: 10.1212/WNL.0000000000001335.
Engedal TS, Ørding H, Vilholm OJ Changing the needle for lumbar punctures: results from a prospective study. Clin Neurol Neurosurg. 2015 Mar;130:74-9. doi: 10.1016/j.clineuro.2014.12.020. Epub 2015 Jan 6.
Ferre RM, Sweeney TW Emergency physicians can easily obtain ultrasound images of anatomical landmarks relevant to lumbar puncture. Am J Emerg Med. 2007 Mar;25(3):291-6.
Grau T, Leipold RW, Conradi R, Martin E, Motsch J Ultrasound imaging facilitates localization of the epidural space during combined spinal and epidural anesthesia. Reg Anesth Pain Med. 2001 Jan-Feb;26(1):64-7.
Huang MY, Lin AP, Chang WH Ultrasound-assisted localization for lumbar puncture in the ED. Am J Emerg Med. 2008 Oct;26(8):955-7. doi: 10.1016/j.ajem.2008.03.007.
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.