title: Diagnostic accuracy of tissue impedance measurement interpretation for correct Veress needle placement in canine cadavers.
abstract: OBJECTIVE
  To establish the diagnostic accuracy of tissue impedance measurement interpretation (TIMI) for determining correct versus incorrect Veress needle placement.
  
  
  METHODS
  Prospective, randomized, blinded trial.
  
  
  METHODS
  Canine cadavers (n = 20).
  
  
  METHODS
  Two laparoscopists (1 experienced, 1 novice), blinded to tissue impedance measurement results, placed reusable Veress needles in canine cadavers in a randomized order. A 3rd individual interpreted impedance measurements as consistent with correct or incorrect Veress needle placement. Veress needle tip locations were marked by injecting contrasting colors of India ink. Tissue dissection was performed to localize ink. Sensitivity, specificity, accuracy, precision, and kappa statistics for TIMI for placements by the experienced and novice laparoscopist were determined. P < .05 was considered significant.
  
  
  RESULTS
  TIMI identified 29/33 correct and 7/7 incorrect placements, respectively. Impedance measurement interpretation had 87.9% sensitivity, 100% specificity, 90% accuracy, and 100% precision overall. Agreement between TIMI and Veress needle location was moderate (kappa 0.50, P = .01) for placements by the experienced laparoscopist and very high (kappa 0.88, P < .01) for the novice laparoscopist.
  
  
  CONCLUSIONS
  Diagnostic accuracy of TIMI for Veress needle placement was higher than has been reported for other tests, and TIMI had a shallow learning curve. TIMI successfully detected all incorrect Veress needle placements. Further prospective evaluation of Veress needle placement with and without TIMI is warranted to determine if its use increases operator detection of inappropriate Veress needle placements or decreases installment phase complication rates.
authors: Department of Small Animal Clinical Sciences at the College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA. jwhittemore@utk.edu
authors: Jacqueline C
authors: JC
authors: Whittemore
authors: Amanda
authors: A
authors: Mitchell
authors: Sara
authors: S
authors: Hyink
authors: Ann
authors: A
authors: Reed
mesh_terms: D000818:Animals; D002102:Cadaver; D004285:Dogs; D017097:Electric Impedance; D055724:Electrophysiological Phenomena / Q000502:physiology*; D010535:Laparoscopy / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D009339:Needles / Q000662:veterinary*