Técnicas de epiduroscopia en el tratamiento del dolor lumbar: una revisión sistemática de la literatura

Objetivo: El dolor lumbar es una de las patologías más complejas en términos de costo-efectividad de los tratamientos. En este estudio evaluamos la utilidad de la epiduroscopia en el manejo de dolor lumbar, y su beneficio en comparación con las técnicas percutáneas tradicionales. Materiales y métodos: Se realizó una búsqueda de manera sistemática en las bases de datos PubMed, EMBASE, Cochrane y MedLine para artículos publicados entre enero de 1990 y diciembre de 2013. Se incluyeron estudios clínicos descriptivos y experimentos clínicos aleatorizados, excluyéndose estudios no clínicos, opiniones de expertos, etc. Resultados: Se obtuvieron 353 artículos en las 4 bases de datos, de los cuales sólo 78 pasaron el corte según criterios de exclusión e inclusión. Posteriormente se realizó un análisis crítico de los artículos según parámetros estandarizados. De los 78 artículos evaluados, se incluyeron 24 en la revisión final, 14 estudios evaluaron lisis de adherencias e inyección de esteroides, 3 estudios evaluaron la efectividad de la inyección epidural dirigida por epiduroscopia, mientras que los 7 restantes evaluaron otras intervenciones. Conclusiones: La epiduroscopia es una tecnología útil en el tratamiento del dolor lumbar con diferencias significativas en los resultados a largo plazo en ciertos pacientes. Esta tecnología es más útil en pacientes con antecedente quirúrgico con síntomas persistentes que en pacientes que no han sido intervenidos. De igual manera, cuando el dolor es de características radiculares, los resultados a largo plazo son más favorables que cuando se trata de dolor axial o inespecífico.

Differences in Epidural and Analgesic Use in Patients with Apparent Stage I Endometrial Cancer treated by open versus laparoscopic surgery: results from the randomised LACE trial

Objectives: We compared post-operative analgesic requirements between women with early stage endometrial cancer treated by total abdominal hysterectomy (TAH) or total laparoscopic hysterectomy (TLH). Methods: 760 patients with apparent stage I endometrial cancer were treated in the international, multicentre, prospective randomised trial (LACE) by TAH (n=353) or TLH (n=407) (2005-2010). Epidural, opioid and non-opioid analgesic requirements were collected until ten months after surgery. Results: Baseline demographics and analgesic use were comparable between treatment arms. TAH patients were more likely to receive epidural analgesia than TLH patients (33% vs 0.5%, p<0.001) during the early postoperative phase. Although opioid use was comparable in the TAH vs TLH groups during postoperative 0-2 days (99.7% vs 98.5%, p 0.09), a significantly higher proportion of TAH patients required opioids 3-5 days (70% vs 22%, p<0.0001), 6-14 days (35% vs 15%, p<0.0001), and 15-60 days (15% vs 9%, p 0.02) post-surgery. Mean pain scores were significantly higher in the TAH versus TLH group one (2.48 vs 1.62, p<0.0001) and four weeks (0.89 vs 0.63, p 0.01) following surgery. Conclusion: Treatment of early stage endometrial cancer with TLH is associated with less frequent use of epidural, lower post-operative opioid requirements and better pain scores than TAH.

Epidural analgesia is associated with an increased incidence of postoperative complications in patients requiring an abdominal hysterectomy for early stage endometrial cancer

Objective Analgesia and early quality of recovery may be improved by epidural analgesia. We aimed to assess the effect of receiving epidural analgesia on surgical adverse events and quality of life after laparotomy for endometrial cancer. Methods Patients were enrolled in an international, multicentre, prospective randomised trial of outcomes for laparoscopic versus open surgical treatment for the management of apparent stage I endometrial cancer (LACE trial). The current analysis focussed on patients who received an open abdominal hysterectomy via vertical midline incision only (n = 257), examining outcomes in patients who did (n = 108) and did not (n = 149) receive epidural analgesia. Results Baseline characteristics were comparable between patients with or without epidural analgesia. More patients without epidural (34%) ceased opioid analgesia 3–5 days after surgery compared to patients who had an epidural (7%; p < 0.01). Postoperative complications (any grade) occurred in 86% of patients with and in 66% of patients without an epidural (p < 0.01) but there was no difference in serious adverse events (p = 0.19). Epidural analgesia was associated with increased length of stay (up to 48 days compared to up to 34 days in the non-epidural group). There was no difference in postoperative quality of life up to six months after surgery. Conclusions Epidural analgesia was associated with an increase in any, but not serious, postoperative complications and length of stay after abdominal hysterectomy. Randomised controlled trials are needed to examine the effect of epidural analgesia on surgical adverse events, especially as the present data do not support a quality of life benefit with epidural analgesia. Keywords Endometrial cancer; Hysterectomy; Epidural; Adverse events

Lumbar epidural steroids are not cost effective in sciatica

Background Lumbar Epidural Steroids Injections (ESI’s) have previously been shown to provide some degree of pain relief in sciatica. Number Needed To Treat (NNT) to achieve 50% pain relief has been estimated at 7 from the results of randomised controlled trials. Pain relief is temporary. They remain one of the most commonly provided procedures in the UK. It is unknown whether this pain relief represents good value for money. Methods 228 patients were randomised into a multi-centre Double Blind Randomised Controlled Trial. Subjects received up to 3 ESI’s or intra-spinous saline depending on response and fall off with the first injection. All other treatments were permitted. All received a review of analgesia, education and physical therapy. Quality of life was assessed using the SF36 at 6 points and compared using independent sample t-tests. Follow up was up to 1 yr. Missing data was imputed using last observation carried forward (LOCF). QALY’s (Quality of Life Years) were derived from preference based heath values (summary health utility score). SF-6D health state classification was derived from SF-36 raw score data. Standard gambles (SG) were calculated using Model 10. SG scores were calculated on trial results. LOCF was not used for this. Instead average SG were derived for a subset of patients with observations for all visits up to week 12. Incremental QALY’s were derived as the difference in the area between the SG curve for the active group and placebo group. Results SF36 domains showed a significant improvement in pain at week 3 but this was not sustained (mean 54 Active vs 61 Placebo P<0.05). Other domains did not show any significant gains compared with placebo. For derivation of SG the number in the sample in each period differed. In week 12, average SG scores for active and placebo converged. In other words, the health gain for the active group as measured by SG was achieved by the placebo group by week 12. The incremental QALY gained for a patient under the trial protocol compared with the standard care package was 0.0059350. This is equivalent to an additional 2.2 days of full health. The cost per QALY gained to the provider from a patient management strategy administering one epidural as suggested by results was £25 745.68. This result was derived assuming that the gain in QALY data calculated for patients under the trial protocol would approximate that under a patient management strategy based on the trial results (one ESI). This is above the threshold suggested by some as a cost effective treatment. Conclusions The transient benefit in pain relief afforded by ESI’s does not appear to be cost-effective. Further work is needed to develop more cost-effective conservative treatments for sciatica.

Clinical Studies on Epidural and Spinal Postoperative Analgesia : With Special Reference to Continuous Techniques of Administration and Adjuvant Drugs

Continuous epidural analgesia (CEA) and continuous spinal postoperative analgesia (CSPA) provided by a mixture of local anaesthetic and opioid are widely used for postoperative pain relief. E.g., with the introduction of so-called microcatheters, CSPA found its way particularly in orthopaedic surgery. These techniques, however, may be associated with dose-dependent side-effects as hypotension, weakness in the legs, and nausea and vomiting. At times, they may fail to offer sufficient analgesia, e.g., because of a misplaced catheter. The correct position of an epidural catheter might be confirmed by the supposedly easy and reliable epidural stimulation test (EST). The aims of this thesis were to determine a) whether the efficacy, tolerability, and reliability of CEA might be improved by adding the α2-adrenergic agonists adrenaline and clonidine to CEA, and by the repeated use of EST during CEA; and, b) the feasibility of CSPA given through a microcatheter after vascular surgery. Studies I IV were double-blinded, randomized, and controlled trials; Study V was of a diagnostic, prospective nature. Patients underwent arterial bypass surgery of the legs (I, n=50; IV, n=46), total knee arthroplasty (II, n=70; III, n=72), and abdominal surgery or thoracotomy (V, n=30). Postoperative lumbar CEA consisted of regular mixtures of ropivacaine and fentanyl either without or with adrenaline (2 µg/ml (I) and 4 µg/ml (II)) and clonidine (2 µg/ml (III)). CSPA (IV) was given through a microcatheter (28G) and contained either ropivacaine (max. 2 mg/h) or a mixture of ropivacaine (max. 1 mg/h) and morphine (max. 8 µg/h). Epidural catheter tip position (V) was evaluated both by EST at the moment of catheter placement and several times during CEA, and by epidurography as reference diagnostic test. CEA and CSPA were administered for 24 or 48 h. Study parameters included pain scores assessed with a visual analogue scale, requirements of rescue pain medication, vital signs, and side-effects. Adrenaline (I and II) had no beneficial influence as regards the efficacy or tolerability of CEA. The total amounts of epidurally-infused drugs were even increased in the adrenaline group in Study II (p=0.02, RM ANOVA). Clonidine (III) augmented pain relief with lowered amounts of epidurally infused drugs (p=0.01, RM ANOVA) and reduced need for rescue oxycodone given i.m. (p=0.027, MW-U; median difference 3 mg (95% CI 0 7 mg)). Clonidine did not contribute to sedation and its influence on haemodynamics was minimal. CSPA (IV) provided satisfactory pain relief with only limited blockade of the legs (no inter-group differences). EST (V) was often related to technical problems and difficulties of interpretation, e.g., it failed to identify the four patients whose catheters were outside the spinal canal already at the time of catheter placement. As adjuvants to lumbar CEA, clonidine only slightly improved pain relief, while adrenaline did not provide any benefit. The role of EST applied at the time of epidural catheter placement or repeatedly during CEA remains open. The microcatheter CSPA technique appeared effective and reliable, but needs to be compared to routine CEA after peripheral arterial bypass surgery.

Measurements of Epidural Space Depth Using Preexisting CT Scans Correlate with Loss of Resistance Depth during Thoracic Epidural Catheter Placement.

Background. Thoracic epidural catheters provide the best quality postoperative pain relief for major abdominal and thoracic surgical procedures, but placement is one of the most challenging procedures in the repertoire of an anesthesiologist. Most patients presenting for a procedure that would benefit from a thoracic epidural catheter have already had high resolution imaging that may be useful to assist placement of a catheter. Methods. This retrospective study used data from 168 patients to examine the association and predictive power of epidural-skin distance (ESD) on computed tomography (CT) to determine loss of resistance depth acquired during epidural placement. Additionally, the ability of anesthesiologists to measure this distance was compared to a radiologist, who specializes in spine imaging. Results. There was a strong association between CT measurement and loss of resistance depth (P < 0.0001); the presence of morbid obesity (BMI > 35) changed this relationship (P = 0.007). The ability of anesthesiologists to make CT measurements was similar to a gold standard radiologist (all individual ICCs > 0.9). Conclusions. Overall, this study supports the examination of a recent CT scan to aid in the placement of a thoracic epidural catheter. Making use of these scans may lead to faster epidural placements, fewer accidental dural punctures, and better epidural blockade.

Effect of ritonavir-induced cytochrome P450 3A4 inhibition on plasma fentanyl concentrations during patient-controlled epidural labor analgesia: a pharmacokinetic simulation.

BACKGROUND: Ritonavir inhibition of cytochrome P450 3A4 decreases the elimination clearance of fentanyl by 67%. We used a pharmacokinetic model developed from published data to simulate the effect of sample patient-controlled epidural labor analgesic regimens on plasma fentanyl concentrations in the absence and presence of ritonavir-induced cytochrome P450 3A4 inhibition. METHODS: Fentanyl absorption from the epidural space was modeled using tanks-in-series delay elements. Systemic fentanyl disposition was described using a three-compartment pharmacokinetic model. Parameters for epidural drug absorption were estimated by fitting the model to reported plasma fentanyl concentrations measured after epidural administration. The validity of the model was assessed by comparing predicted plasma concentrations after epidural administration to published data. The effect of ritonavir was modeled as a 67% decrease in fentanyl elimination clearance. Plasma fentanyl concentrations were simulated for six sample patient-controlled epidural labor analgesic regimens over 24 h using ritonavir and control models. Simulated data were analyzed to determine if plasma fentanyl concentrations producing a 50% decrease in minute ventilation (6.1 ng/mL) were achieved. RESULTS: Simulated plasma fentanyl concentrations in the ritonavir group were higher than those in the control group for all sample labor analgesic regimens. Maximum plasma fentanyl concentrations were 1.8 ng/mL and 3.4 ng/mL for the normal and ritonavir simulations, respectively, and did not reach concentrations associated with 50% decrease in minute ventilation. CONCLUSION: Our model predicts that even with maximal clinical dosing regimens of epidural fentanyl over 24 h, ritonavir-induced cytochrome P450 3A4 inhibition is unlikely to produce plasma fentanyl concentrations associated with a decrease in minute ventilation.

Effects of Local Anesthetic on the Time Between Analgesic Boluses and the Duration of Labor in Patient-Controlled Epidural Analgesia: Prospective Study of Two Ultra-Low Dose Regimens of Ropivacaine and Sufentanil

BACKGROUND: Patient-controlled epidural analgesia with low concentrations of anesthetics is effective in reducing labor pain. The aim of this study was to assess and compare two ultra-low dose regimens of ropivacaine and sufentanil (0.1% ropivacaine plus 0.5 μg.ml-1 sufentanil vs. 0.06% ropivacaine plus 0.5 μg.ml-1 sufentanil) on the intervals between boluses and the duration of labor. MATERIAL AND METHODS: In this non-randomized prospective study, conducted between January and July 2010, two groups of parturients received patient-controlled epidural analgesia: Group I (n = 58; 1 mg.ml-1 ropivacaine + 0.5 μg.ml-1 sufentanil) and Group II (n = 57; 0.6 mg.ml-1 ropivacaine + 0.5 μg.ml-1 sufentanil). Rescue doses of ropivacaine at the concentration of the assigned group without sufentanil were administered as necessary. Pain, local anesthetic requirements, neuraxial blockade characteristics, labor and neonatal outcomes, and maternal satisfaction were recorded. RESULTS: The ropivacaine dose was greater in Group I (9.5 [7.7-12.7] mg.h-1 vs. 6.1 [5.1-9.8 mg.h-1], p < 0.001). A time increase between each bolus was observed in Group I (beta = 32.61 min, 95% CI [25.39; 39.82], p < 0.001), whereas a time decrease was observed in Group II (beta = -1.40 min, 95% CI [-2.44; -0.36], p = 0.009). The duration of the second stage of labor in Group I was significantly longer than that in Group II (78 min vs. 65 min, p < 0.001). CONCLUSIONS: Parturients receiving 0.06% ropivacaine exhibited less evidence of cumulative effects and exhibited faster second stage progression than those who received 0.1% ropivacaine.

Comparación entre analgesia epidural continua vs bloqueo nervio periférico en niños llevados a cirugía múltiple de miembros inferiores

Las cirugías reconstructivas múltiples de miembros inferiores son intervenciones quirúrgicas que implican un difícil manejo analgésico en el postoperatorio, actualmente la técnica analgésica usada es la analgesia peridural; sin embargo los efectos adversos asociados a esta no la hacen una técnica ideal para manejo de dolor. Los bloqueos de nervio periférico han aparecido como una alternativa para el manejo del dolor; pero no se ha difundido ampliamente su uso. Se pretende evaluar la disminución de efectos adversos con el uso de bloqueos de nervio periférico sobre la analgesia epidural. Este estudio piloto inicial se realizo para verificar efectividad técnicas a usar y problemas que se pudieran presentar. Se aplico el protocolo en 23 pacientes que fueron llevados a cirugía de miembros inferiores, se dividieron en 2 grupos 11 recibieron bloqueos de nervio periférico y 12 analgesia epidural. Se les realizo seguimiento por 48 horas y se evaluó el control del dolor, consumo de opioides y efectos adversos. El tiempo de colocación del bloqueo fue similar en ambos grupos, el grupo de bloqueos presento menos episodios de dolor y menos episodios de dolor severo. No se presento retención urinaria en ningún paciente pero en el grupo de epidural se presento mayor incidencia de nausea y vomito (60% vs 45%). Se encontró que los bloqueos de nervio periférico son una adecuada opción para el manejo del dolor en este tipo de cirugías; y al parecer disminuye la incidencia de eventos adversos asociados a la analgesia epidural.

Epidural analgesia with morphine or buprenorphine in ponies with lipopolysaccharide (LPS)-induced carpal synovitis

This study evaluated the analgesia effects of the epidural administration of 0.1 mg/kg bodyweight (BW) of morphine or 5 mu g/kg BW of buprenorphine in ponies with radiocarpal joint synovitis. Six ponies were submitted to 3 epidural treatments: the control group (C) received 0.15 mL/kg BW of a 0.9% sodium chloride (NaCl) solution; group M was administered 0.1 mg/kg BW of morphine; and group B was administered 5 mu g/kg BW of buprenorphine, both diluted in 0.9% NaCl to a total volume of 0.15 mL/kg BW administered epidurally at 10 s/mL. The synovitis model was induced by injecting 0.5 ng of lipopolysaccharide (LPS) in the left or right radiocarpal joint. An epidural catheter was later introduced in the lumbosacral space and advanced up to the thoracolumbar level. The treatment started 6 h after synovitis induction. Lameness, maximum angle of carpal flexion, heart rate, systolic arterial pressure, respiratory rate, temperature, and intestinal motility were evaluated before LPS injection (baseline), 6 h after LPS injection (time 0), and 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, and 24 h after treatments. Although the model of synovitis produced clear clinical signs of inflammation, the lameness scores in group C were different from the baseline for only up to 12 h. Both morphine and buprenorphine showed a reduction in the degree of lameness starting at 0.5 and 6 h, respectively. Reduced intestinal motility was observed at 0.5 h in group M and at 0.5 to 1 h in group B. Epidural morphine was a more effective analgesic that lasted for more than 12 h and without side effects. It was concluded that morphine would be a valuable analgesic option to alleviate joint pain in the thoracic limbs in ponies.

Effect of low-dose mobile versus traditional epidural techniques on mode of delivery: a randomised controlled trial

Background

Epidural analgesia is the most effective labour pain relief but is associated with increased rates of instrumental vaginal delivery and other effects, which might be related to the poor motor function associated with traditional epidural. New techniques that preserve motor function could reduce obstetric intervention. We did a randomised controlled trial to compare low-dose combined spinal epidural and low-dose infusion (mobile) techniques with traditional epidural technique.
Methods

Between Feb 1, 1999, and April 30, 2000, we randomly assigned 1054 nulliparous women requesting epidural pain relief to traditional (n=353), low-dose combined spinal epidural (n=351), or low-dose infusion epidural (n=350). Primary outcome was mode of delivery, and secondary outcomes were progress of labour, efficacy of procedure, and effect on neonates. We obtained data during labour and interviewed women postnatally.
Findings

The normal vaginal delivery rate was 35·1% in the traditional epidural group, 42·7% in the low-dose combined spinal group (odds ratio 1·38 [95% CI 1·01–1·89]; p=0·04); and 42·9% in the low-dose infusion group (1·39 [1·01–1·90]; p=0·04). These differences were accounted for by a reduction in instrumental vaginal delivery. Overall, 5 min APGAR scores of 7 or less were more frequent with low-dose technique. High-level resuscitation was more frequent in the low-dose infusion group.