Chin KW, Chin NM, Chin MK Spread of spinal anaesthesia with 0.5% bupivacaine: influence of the vertebral interspace and speed of injection. Med J Malaysia. 1994 Jun;49(2):142-8.
Furness G, Reilly MP, Kuchi S An evaluation of ultrasound imaging for identification of lumbar intervertebral level. Anaesthesia. 2002 Mar;57(3):277-80.
Halpern SH, Banerjee A, Stocche R, Glanc P The use of ultrasound for lumbar spinous process identification: A pilot study. Can J Anaesth. 2010 Sep;57(9):817-22. doi: 10.1007/s12630-010-9337-x. Epub 2010 May 25.
Lowson SM, Brown J, Wilkins CJ Influence of the lumbar interspace chosen for injection on the spread of hyperbaric 0.5% bupivacaine. Br J Anaesth. 1991 Apr;66(4):465-8.
Perlas A Evidence for the use of ultrasound in neuraxial blocks. Reg Anesth Pain Med. 2010 Mar-Apr;35(2 Suppl):S43-6. doi: 10.1097/AAP.0b013e3181d2462e. Review.
Taylor JA Lumbosacral subarachnoid tap. J Urol 1940;43:561
Watson MJ, Evans S, Thorp JM Could ultrasonography be used by an anaesthetist to identify a specified lumbar interspace before spinal anaesthesia? Br J Anaesth. 2003 Apr;90(4):509-11.
Hypotension in Spinal Anesthesia for Total Knee Joint Arthroplasty: a Comparison of Taylor's Approach With Paramedian Lumbar Approach
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.
