Hypovolemia — Detection of Hypovolemia Using Pleth Variability Index (PVI)
Citation(s)
Cannesson M, Desebbe O, Rosamel P, Delannoy B, Robin J, Bastien O, Lehot JJ Pleth variability index to monitor the respiratory variations in the pulse oximeter plethysmographic waveform amplitude and predict fluid responsiveness in the operating theatre. Br J Anaesth. 2008 Aug;101(2):200-6. doi: 10.1093/bja/aen133. Epub 2008 Jun 2.
Cooke WH, Ryan KL, Convertino VA Lower body negative pressure as a model to study progression to acute hemorrhagic shock in humans. J Appl Physiol (1985). 2004 Apr;96(4):1249-61. Review.
Keller G, Cassar E, Desebbe O, Lehot JJ, Cannesson M Ability of pleth variability index to detect hemodynamic changes induced by passive leg raising in spontaneously breathing volunteers. Crit Care. 2008;12(2):R37. doi: 10.1186/cc6822. Epub 2008 Mar 6.
Nilsson L, Goscinski T, Kalman S, Lindberg LG, Johansson A Combined photoplethysmographic monitoring of respiration rate and pulse: a comparison between different measurement sites in spontaneously breathing subjects. Acta Anaesthesiol Scand. 2007 Oct;51(9):1250-7. Epub 2007 Aug 15.
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.
