No abstract

FRCPCPurpose: To examine the reliability of low current electrical epidural stimulation to confirm epidural catheter placement. Methods: Forty patients with epidural catheters (I 9G Arrow Flextip plus) already in place for post-operative pain management were studied. An adapter (Arrow-Johans ECG Adapter) was attached to the connector of the epidural catheter. The epidural catheter and adapter were filled with normal saline. The cathode lead of the nerve stimulator was attached to the metal hub of the adapter. Catheter placement was judged to be correct or incorrect, depending upon the presence or absence of truncal or limb movement to I Hz stimulation (I -10 mA). A standard test dose (3 ml lidocaine 1.5% with 1:200,000 epinephrine) was then injected. The efficacy of the epidural morphine was assessed independently. Results: The sensitivity and specificity of the test was 100% and 91.6% compared with the standard test dose. The positive and negative predictive value was 96% and 100%. In predicting the clinical effect of epidural morphine, the sensitivity and specificity was 96. I% and 76.9%. The positive and negative predictive value was 89% and 90%. The correlation of unilateral or bilateral motor response from the test and sensory response from the lidocaine test with sensitivity and specificity was 91.6% and 53.0%. The predictive value for unilateral response was 61% and for bilateral was 88%. Conclusion: This study establishes this test as a simple, objective and reliable technique for confirmation of epidural catheter placement.Objectif: D&erminer la fiabilit~ d'une stimulation p&idurale ~lectrique de faible intensit~ utilis~e pour confirmer la raise en place d'un cath&er p&idural. M&hode : Quarante patients, ~. qui on avait d~j~ install~ un cath&er p&idural (Arrow Flex-tip plus 19G) pour traiter la douleur post op&atoire, ont particip~ ~ I'&ude. Un adaptateur (Arrow-Johans EXG Adapter) a ~t~ fix~ au connecteur du cath&er. Ce cath&er et I'adaptateur ont ~t~ remplis de s&um physiologique. I'~lectrode cathodique du neurostimulateur a ~t~ fix~e ~ la garde m~tallique de I'adaptateur. La mise en place du cath&er &ait jug~e correcte ou incorrecte selon la pr&ence ou I'absence d'un mouvement du tronc ou d'un membre une stimulation de I Hz (I-10 mA). Une dose-test standard (3 ml de lidocaine ~ 1,5 % avec I : 200 000 d'~pin~phrine) a ~t~ inject~e par la suite. Eefficacit~ de la morphine p&idurale a ~t~ &alu~e s~par~ment. R&ultats : La sensibitit~ et la sp&ificit~ du test &aient de 100 % et de 91,6 % en comparaison avec la dosetest standard. Les valeurs de la prediction positive et n~gative ~taient de 96 % et de 100 %. Concemant la pr~-diction de I'effet clinique de la morphine p6ridurale, la sensibilit~ et la sp~cificit~ &aient de 96, 1% et de 76,9 %. Les valeurs de la prediction positive et n~gative &aient de 89 % et 90 %. La corr&tion entre une r~ponse motrice unilat&ale ou bilat&ale au test et une r~ponse sensorielle au test de lidocaine avec sensibilit~ et sp&i-ficit~ &ait de 91,6 % et 53,0 %. La valeur predictiv...

Polymethylmethacrylate (PMMA) bone cement technology has progressed from industrial Plexiglass administration in the 1950s to the recent advent of nanoparticle additives. Additives have been trialed to address problems with modern bone cements such as the loosening of prosthesis, high post-operative infection rates, and inflammatory reduction in interface integrity. This review aims to assess current additives used in PMMA bone cements and offer an insight regarding future directions for this biomaterial. Low index (< 15%) vitamin E and low index (< 5 g) antibiotic impregnated additives significantly address infection and inflammatory problems, with only modest reductions in mechanical strength. Chitosan (15% w/w PMMA) and silver (1% w/w PMMA) nanoparticles have strong antibacterial activity with no significant reduction in mechanical strength. Future work on PMMA bone cements should focus on trialing combinations of these additives as this may enhance favourable properties.