1 Oxford, UK
EditorThe length at which an epidural catheter is placed within the epidural space affects the risk of post-procedural complications.13 Catheters inserted to a depth of 8 vs 6 cm are more likely to result in i.v. cannulation.1 A depth of insertion of 7 vs 5 cm was associated with i.v. location and inadequate analgesia.2 On the other hand, catheter insertion of less than 4 cm may be related to a higher rate of displacement, especially in obese patients.3 Clearly, knowledge of the catheter length in the epidural space is of prime importance. We report a case of incorrectly positioned distance markings on an epidural catheter inspected at our clinic.
We employed a catheter taken from a teaching set to familiarize us with its recently modified distance markings (Perifix®-Katheter; 1.05 mm outer diameter for use with 16G Tuohy needle; Braun Melsungen, Germany). In keeping with standard practice, this catheter had been added to the set from a stock of regular epidural catheters for clinical use.
Figure 1 shows the results of our measurements. The first marking on this catheter (lower one in the Figure) was at 7 cm. The 10 cm mark was found at 12.4 cm. Three new catheter sets, taken for reference, showed the 10 cm mark at 10.7 cm in accordance with the manufacturers specifications (upper catheter in Figure 1).
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A. Goebel
K. Ovenden
C. Glynn
Oxford, UK
References
1 DAngelo R, Berkebile BL, Gerancher JC. Prospective examination of epidural catheter insertion. Anesthesiology 1996; 84: 8893[ISI][Medline]
2 Beilin Y, Bernstein HH, Zucker-Pinchoff B. The optimal distance that a multiorifice epidural catheter should be threaded into the epidural space. Anesth Analg 1995; 81: 3014[Abstract]
3 Hamilton CL, Riley ET, Cohen SE. Changes in the position of epidural catheters associated with patient movement. Anesthesiology 1997; 86: 77884[ISI][Medline]