title: Diagnostic procedures for catheter malfunction in programmable implantable intraperitoneal insulin infusion devices.
abstract: OBJECTIVE
  To evaluate the roles of 1) abdominal radiography, 2) a pressure diagnostic procedure (PDP) using a standardized diluent infusion into the catheter sideport, and 3) radiocontrast imaging of the catheter lumen as procedures for diagnosing catheter malfunction in diabetic patients implanted with a programmable intraperitoneal infusion device.
  
  
  METHODS
  Sixteen type I diabetic patients implanted with Infusaid programmable intraperitoneal insulin pumps were studied. The ability of the above three procedures to assist diagnosis of catheter malfunction and distinguish between occlusion and catheter breakage was retrospectively analyzed. Glycated hemoglobin was measured to determine the clinical importance of catheter malfunctions and decreases in pump flow due to insulin aggregation in the pump chamber.
  
  
  RESULTS
  Mean glycated hemoglobin levels increased significantly from 8.0 +/- 0.3 to 9.0 +/- 0.4% (P < 0.05) before and after catheter malfunction, but not during pump flow slowdowns. Mean peak pressure during PDP was 1.96 +/- 0.14 psi (P < 0.01 vs. normal) in reversibly occluded catheters and 1.86 +/- 0.35 psi (P < 0.05 vs. normal) in broken catheters, compared with 1.32 +/- 0.23 psi in normal catheters. Decay times during PDP were > 50 s for both reversibly occluded and broken catheters (P < 0.001 vs. normal of 3.6 +/- 0.82 s). Abdominal radiographs and sideport injections of contrast material were used to distinguish the types of broken catheters.
  
  
  CONCLUSIONS
  Catheter breakage and occlusion are complications in implantable insulin infusion systems and result in metabolic deterioration. The presence of a sideport allows pressure data and radiographic procedures to assist in determining the cause of catheter malfunction. A diagnostic algorithm was generated to improve efficiency in investigating catheter problems.
authors.affiliation: Department of Medicine, College of Medicine, University of California, Irvine 92717.
authors.forename: C L
authors.initials: CL
authors.lastname: Olsen
authors.forename: D S
authors.initials: DS
authors.lastname: Turner
authors.forename: M
authors.initials: M
authors.lastname: Iravani
authors.forename: K
authors.initials: K
authors.lastname: Waxman
authors.forename: J L
authors.initials: JL
authors.lastname: Selam
authors.forename: M A
authors.initials: MA
authors.lastname: Charles
mesh_terms: D000328:Adult; D001786:Blood Glucose; D002408:Catheters, Indwelling / Q000009:adverse effects*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000000981:diagnostic imaging / Q000628:therapy*; D003952:Diagnostic Imaging / Q000379:methods*; D004868:Equipment Failure; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007332:Insulin Infusion Systems; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose; D007328:Insulin