title: Antipyrine clearance in surgical patients maintained on hypocaloric peripheral parenteral nutrition.
abstract: BACKGROUND
  Antipyrine clearance (CLAP) constitutes a sensitive indicator of hepatic microsomal enzyme activity providing specific information on hepatic function. The purpose of this study was to evaluate the influence of hypocaloric peripheral parenteral nutrition on CLAP in patients receiving nutrition support after elective surgery.
  
  
  METHODS
  CLAP was measured in 15 patients before elective gastrointestinal surgery and 6 days after the surgery. Antipyrine (1 g) was administered orally, and CLAP was determined by the one-sample method. Subjects received a postoperative 786 kcal/d regimen providing 66 g of amino acid per day and 133 g of glucose per day for 5 days. Nutritional status was evaluated by anthropometric parameters. A control group of 15 patients received no postoperative hypocaloric peripheral parenteral nutrition but received conventional fluid therapy.
  
  
  RESULTS
  Mean CLAP was increased by 61% (0.66 +/- 0.06 mL/min.kg-1 body wt vs 0.41 +/- 0.05 mL/min.kg-1 body wt in the preoperative period; p < .001), and antipyrine half-life was reduced by 42% (10.9 +/- 1.0 hours vs 18.9 +/- 2.0 hours; p < .001) after 5 days of hypocaloric peripheral parenteral nutrition. No significant modification was shown among control patients in CLAP (0.54 +/- 0.07 mL/min.kg-1 body wt vs 0.46 +/- 0.05 mL/min.kg-1 body wt in the preoperative period) or in antipyrine half-life (14.0 +/- 1.4 hours vs 16.5 +/- 1.8 hours). No significant correlation was observed between CLAP changes and those for the nutritional status of the patients.
  
  
  CONCLUSIONS
  The results of our study indicate that oxidative drug-metabolizing capacity is increased in surgical patients maintained on hypocaloric peripheral parenteral nutrition. Clinicians should be conscious of the potential of this effect for altering the efficacy or toxicity of many therapeutic agents.
authors.affiliation: Department of Physiology, University of León, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Jorquera
authors.forename: M
authors.initials: M
authors.lastname: Almar
authors.forename: C
authors.initials: C
authors.lastname: Martinez
authors.forename: M
authors.initials: M
authors.lastname: Gonzalez-Sastre
authors.forename: J M
authors.initials: JM
authors.lastname: Culebras
authors.forename: J
authors.initials: J
authors.lastname: Gonzalez-Gallego
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000983:Antipyrine / Q000493:pharmacokinetics; D002149:Energy Intake; D005260:Female; D006207:Half-Life; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009752:Nutritional Status; D010288:Parenteral Nutrition; D012463:Saliva / Q000378:metabolism; D013514:Surgical Procedures, Operative
chemical_list: D000983:Antipyrine