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J E Snell

Publications and source records attributed to J E Snell.

7 recordsLinked to original sources
PubMed1996

Analysis of complications and long-term outcome of trauma patients with needle catheter jejunostomy.

Enteral feedings demonstrably lower the risk of septic complications. However, complications associated with the specific method of enteral feeding may diminish the intended benefits. The objective was to determine the short and long-term complications associated with needle catheter jejunostomy (NCJ). All NCJs placed at a Level I trauma center over an 8-year period were reviewed. Short-term complications directly attributable to NCJ were defined as tube leakage with intraabdominal or intraparietal spillage, intraabdominal abscess, small bowel obstruction at the catheter site, tube blockage or dislodgement, or soft tissue infection. Telephone interviews were conducted to elicit long-term complications, including operations to correct a complication of the NCJ, chronic nausea, vomiting, diarrhea, bloating, hernia, or change in appetite. Of 122 study patients, short-term complications (N = 22) included two abscesses, one bowel obstruction, two abdominal wall infections, three leaks, one local soft tissue infection, one enterocutaneous fistula, three blocked catheters, and nine tube dislodgements. Fifty patients were contacted by telephone; 19 had long-term complications, including two operations for adhesions. Complications associated with NCJ are common, may be life-threatening, and may require surgical intervention. In many cases, other methods of enteral feeding access may be preferable to NCJ.

Abdominal Abscess↗
PubMed1975

Cell kinetic approach to optimising dose distribution in radiation therapy.

A simple tumour-cell radiation-response model was coupled to a dose-calculation routine and applied to a clinical situation in radiation therapy. The dose distributions resulting from various settings of two radiation fields, as well as the tumour response under various assumptions regarding sensitivity and distribution of tumour cells, were calculated automatically. The probability of zero surviving tumour cells after 30 fractions was taken as a measure of goodness of the dose distributions and was found to vary rather smoothly over the parameter intervals considered. For some parameters a distinct optimum was found, rather insensitive to different assumptions regarding cell response. A tolerance factor for healthy tissue, based on a dose-volume relationship, was also considered. It is concluded that a cell kinetic approach to automatic optimisation of field parameters in external radiation therapy might be realistic both from computional and economic points of view.

Cell Survival↗
PubMed1975

Errors and uncertainties in external radiation therapy. A system analysis with a cell kinetic model.

The relative importance of accurate knowledge and control of various biologic and physical factors in external radiation therapy was estimated with a simple cell kinetic treatment response model for a simulated tumour therapy situation. A set of parameter values was chosen for a reference case so that the calculated probability of zero surviving tumour cells was about 0.5. The parameters were varied, one at a time, over a range that was considered representative with respect to uncertainty in dose calculation, dose delivery and the description of the pertinent patient data. Also parameters in the cell kinetic model were varied. The calculations demonstrated a strong influence on the number of surviving cells from even moderate changes in the parameters which affect the tumour dose. Predictions with regard to curability are heavily dependent on the reliability of the biologic parameters in the model.

Cell Survival↗