Parry SM, Huang M, Needham DM Evaluating physical functioning in critical care: considerations for clinical practice and research. Crit Care. 2017 Oct 4;21(1):249. doi: 10.1186/s13054-017-1827-6.
Petros S, Engelmann L Validity of an abbreviated indirect calorimetry protocol for measurement of resting energy expenditure in mechanically ventilated and spontaneously breathing critically ill patients. Intensive Care Med. 2001 Jul;27(7):1164-8. doi: 10.1007/s001340100941.
Reid CL Poor agreement between continuous measurements of energy expenditure and routinely used prediction equations in intensive care unit patients. Clin Nutr. 2007 Oct;26(5):649-57. doi: 10.1016/j.clnu.2007.02.003. Epub 2007 Apr 6.
Wei X, Day AG, Ouellette-Kuntz H, Heyland DK The Association Between Nutritional Adequacy and Long-Term Outcomes in Critically Ill Patients Requiring Prolonged Mechanical Ventilation: A Multicenter Cohort Study. Crit Care Med. 2015 Aug;43(8):1569-79. doi: 10.1097/CCM.0000000000001000.
Wichansawakun S, Meddings L, Alberda C, Robbins S, Gramlich L Energy requirements and the use of predictive equations versus indirect calorimetry in critically ill patients. Appl Physiol Nutr Metab. 2015 Feb;40(2):207-10. doi: 10.1139/apnm-2014-0276. Epub 2014 Oct 27.
Feeding With Indirect Calorimetry and Cycling in the Elderly Intensive Care Patient
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.
