The influence of patient position on withdrawal force of lumbar epidural catheters after total knee arthroplasty: A randomized trial.
OBJECTIVE
Elderly patients with degenerative knee disease may have accompanying degenerative spine conditions. There are no studies on lumbar epidural catheter withdrawal forces in these patients. The aim of this study was to investigate withdrawal forces and possible associated risk factors in patients undergoing total knee arthroplasty (TKA).


METHODS
Prospective randomized trial.


METHODS
Operating room and ward in a university hospital.


METHODS
Seventy-eight patients aged 65 to 80years who were undergoing TKA and combined spinal epidural anesthesia were enrolled.


METHODS
Lumbar epidural catheterization was performed in a lateral position before surgery and the patients were randomly allocated to one of 3 positions for removal: flexed lateral (L), prone (P), and sitting (S). On the third postoperative day, the lumbar epidural catheters were removed by a single investigator with the patient in the assigned position.


METHODS
We measured the peak tension during catheter withdrawal and evaluated the factors affecting peak tension.


RESULTS
The forces required to remove the catheters were considerably greater in the sitting and prone than in the flexed lateral position: group P (3.9N [0.28-10.36]), group S (4.1N [0.04-11.57]), and group L (1.3N [0.07-3.65]) (P<.001). There was a positive correlation between the length of catheter in the epidural space and peak tension (P=.0026, β coefficient=.223).


CONCLUSIONS
For ease of removal of catheters from the lumbar epidural space, the flexed lateral position is recommended for elderly patients undergoing TKA. When placing the epidural catheter, the physician should be careful not to insert a catheter that is excessively long.
Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 135-710, South Korea. Electronic address: youngri.kim@samsung.com.
Young Ri
YR
Kim
Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 135-710, South Korea. Electronic address: jiwon0715.choi@samsung.com.
Ji Won
JW
Choi
Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 135-710, South Korea. Electronic address: wooseog.sim@samsung.com.
Woo Seog
WS
Sim
Zein (ZEropaIN) Pain Treatment Clinic, 7 Seongbuk-Ro, Seongbuk-Gu, Seoul, 136-822, Republic of Korea. Electronic address: cjlee.mdphd@gmail.com.
Chul Joong
CJ
Lee
Zein (ZEropaIN) Pain Treatment Clinic, 7 Seongbuk-Ro, Seongbuk-Gu, Seoul, 136-822, Republic of Korea. Electronic address: culmanss@gmail.com.
Choohoon
C
Chang
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000767:Anesthesia, Epidural / Q000009:adverse effects* / Q000295:instrumentation*; D019645:Arthroplasty, Replacement, Knee; D057785:Catheters; D004824:Epidural Space; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D020370:Osteoarthritis, Knee / Q000601:surgery*; D056888:Patient Positioning; D011312:Pressure; D011446:Prospective Studies; D012737:Sex Factors
Elderly patients; Epidural catheterization; Total knee arthroplasty; Withdrawal force