Influence of patient position on withdrawal forces during removal of lumbar extradural catheters

Abstract

We have investigated the force required to remove lumbar extradural catheters from 88 parturients to determine the effects of patient positioning at removal, relative to the position at insertion. Parturients were allocated randomly to one of four groups: LS (lateral insertion, sitting withdrawal), LL (lateral insertion, flexed lateral withdrawal), SL (sitting insertion, lateral withdrawal) or SS (sitting insertion, sitting withdrawal). In both positions, the lumbar spine was kept maximally flexed. The force required to remove the catheter was measured at withdrawal. We found that the withdrawal force was influenced by the relationship between the position at removal and that at insertion, and we recommend that for ease of removal, patients should be placed in the same position as they were at the time of insertion. Compared with all other groups, the withdrawal force in patients in group LS was significantly greater (P < 0.05).

On knots in epidural catheters: a case report and a review of the literature

“…Removal forces are lowest when the insertion and removal positions are similar. 27,28 If this fails, other patient positions and various degrees of lumbar flexion or extension can be tried.…”

A knotty affair

“…It was shown earlier that the best position for the easy retrieval of an epidural catheter was the position in which it was sited. 5 Further, it has been reported that steady traction would allow the catheter and the knot to decrease in diameter and facilitate easy passage through the ligaments. 1 However, in the case of our patient, steady traction in the said position led to stretching and thinning of the catheter and fearing the possibility that it would break, we stopped pulling.…”

Quebra de cateter no espaço peridural

“…Some conducts are suggested in cases of difficult catheter removal: stop efforts for about 15 to 30 minutes to allow tissues to relax; mild traction in different directions and varying degrees of flexion and extension of the spine. Other suggestions include placing a light weight at the end of the catheter for soft and constant traction, introduction of a Tuohy needle to work as a guide and injection of NS to detect possible kink or knot formation 5, 16 . The position of the patient during insertion of the catheter is the most important factor to determine the position for catheter removal, although several studies have described that the lateral decubitus is better that the sitting position, since the force of traction would be two and a half times smaller 5,6,16 .…”

“…Other suggestions include placing a light weight at the end of the catheter for soft and constant traction, introduction of a Tuohy needle to work as a guide and injection of NS to detect possible kink or knot formation 5, 16 . The position of the patient during insertion of the catheter is the most important factor to determine the position for catheter removal, although several studies have described that the lateral decubitus is better that the sitting position, since the force of traction would be two and a half times smaller 5,6,16 . When facing breakage of a catheter during removal, the different authors agree that the treatment of small fragments in an asymptomatic patient should be conservative, informing the patient of the complication 1 .…”

“…Nos casos de difícil remoção de cateter, sugerem-se algumas condutas: descontinuar os esforços por cerca de 15 a 30 minutos permitindo relaxamento dos tecidos, e tentar tração suave em diferentes posições e graus variados de flexão e extensão da coluna. Outras orientações são amarrar peso leve que provoque tração suave e constante, introdução de uma agulha Tuohy para servir de guia e injeção de solução fisiológica a 0,9% para avaliar possível acotovelamento ou formação de nó 5, 16 . O posicionamento do paciente durante a inserção do cateter é o fator mais importante na determinação do posicionamento para a retirada, embora diversos trabalhos tenham descrito que o decúbito lateral é melhor que a posição sentada, pois a força de tração seria de até duas vezes e meia menor 5,6,16 .…”