John B. Pietsch, M.D.
Professor of Surgery and Pediatrics
Phone: (615) 936-1050 (x 6-1050)
Assessment of Body Composition in Children with Cancer
This study will determine the changes in body composition that occur in children with cancer from diagnosis to end of therapy using bioelectrical impedance analysis (BIA). BIA is being compared to standard nutritional assessment measures (weight, serum albumin). the goal is to determine if a relationship exists between body composition determined by BIA and positive blood cultures, bone marrow recovery after chemotherapy and outcome.
Assessment of Body Composition in Children on ECMO
Extracorporeal membrane oxygenation (ECMO) is often a life-saving therapy in desperately ill patients. Many of these patients are fluid overloaded at the time of initiation of ECMO support. There is evidence this fluid imbalance is often exacerbated on ECMO and aggressive diuresis or hemofiltration are often employed to treat this. The duration of ECMO support is related to the fluid balance in the patient. Weighing a patient on ECMO is not practical in that the tubing attached to the patient is critical and displacement can be catastrophic. Thus, the clinician relies on clinical assessment and intake and output data. It is not uncommon to under or over diurese patients, therefore a non-invasive method of determining fluid status is potentially quite useful. Bioelectrical impedance analysis (BIA) is such a method. BIA has proven to be useful in a variety of fluid balance studies in patient's receiving hemodialysis. In addition to determining body water distribution, assessment of nutritional status can be determined. Bioelectrical impedance analysis (BIA) is a technique for measuring body composition in clinical settings. Bioelectrical impedance theory is based on a concept of the body as an ionic conductor, the resistance of which depends on length and cross-sectional area (volume), the ionic composition of the conducting volume, and the frequency of the driving current. Bioelectrical impedance has two components, resistance of the tissues themselves and reactance due to the capacitate effect of membranes, tissue interfaces and nonionic tissues. Electrodes are placed on a wrist and an ankle and a mild (less than one milliamp) alternating electrical current is delivered. BIA is noninvasive, takes only a few minutes, and requires no active collaboration on the part of the patient.