Prediction of the distance from skin to epidural space for low-thoracic epidural catheter insertion by computed tomography

Background. It may be clinically useful to predict the depthof the epidural space. Methods. To investigate the accuracy of preoperative abdominalcomputed tomography (CT) in prediction of the distance for low-thoracicepidural insertion, a single group observational study was conductedin 30 male patients undergoing elective major abdominal surgeryrequiring epidural analgesia for postoperative pain relief.Using the paramedian approach, low-thoracic epidural insertionat T10–11 interspace was performed with a standardizedprocedure to obtain an actual insertion length (AIL). Accordingto the principles of trigonometry, an estimated insertion length(EIL) was calculated as 1.26 times the distance from skin toepidural space measured from the preoperative abdominal CT. Results. The mean (SD) EIL and AIL were 5.5 (0.7) and 5.1 (0.6)cm, respectively, with a significant correlation (r=0.899, P<0.01).The EIL tended to have a higher value than the AIL (0.4 (0.3)cm). There were significant correlations of both EIL and AILwith weight (P<0.01), BMI (P<0.01), and body fat percentage(P<0.01), but not with height (P>0.05). Conclusions. We conclude that the preoperative abdominal CTis helpful in prediction of the distance for low-thoracic epiduralinsertion using the paramedian approach. Br J Anaesth 2004; 92: 271–3     

Touch contamination levels during anaesthetic procedures and their relationship to hand hygiene procedures: a clinical audit

After different methods of hand preparation, volunteers rolledsegments of sterile central venous catheter between their fingertips,and bacterial transfer was evaluated by standardized quantitativeculture. The number of bacteria transferred differed betweenmethods (P<0.001). Comparisons were made with the controlgroup (no preparation at all; median, third quartile and maximumcount=6.5, 24, 55). Bacterial transfer was greatly increasedwith wet hands (1227, 1932, 3254; P<0.001). It was reducedwith a new rapid method, based on thorough drying with a combinationof 10 s using a cloth towel followed by either 10 or 20 s witha hot-air towel (0, 3, 7 and 0, 4, 30, respectively; P=0.007and 0.004, respectively). When asked to follow their personalroutines, 10 consultant anaesthetists used a range of methods.Collectively, these were not significantly better than control(7.5, 15, 55; P=0.73), and neither was an air towel alone (2.5,15, 80; P=0.176) nor the hospital’s standard procedure(0, 1, 500; P=0.035). If hand preparation is needed, an adequateand validated method should be used, together with thoroughhand drying. Br J Anaesth 2001; 87: 291–4     

Evaluation of epidural needles

Eight different epidural needles (Tuohy Everett, Pitkin, Braun Perifix and Portex in 16-gauge, and Becton Dickinson Crawford, Becton Dickinson B-D, Monoject and Portex in 18-gauge) were evaluated using a scanning electron microscope and spectral x-ray analysis. Differences were noted in the metal composition, between disposable and reusable needles with respect to molybdenum content. The inner surface of the 18-gauge Crawford needle was found to be the smoothest and it also had the best clearance between the needle and stilette. The Portex 16-gauge had the best needle/stilette fit at its bevel. The hardness of the metal was found to be satisfactory in all the needles.     

Spinal epidural abscess--a rare complication after epidural analgesia for labour and delivery

We report a case of spinal epidural abscess formation aftershort-term epidural catheter placement for analgesia duringlabour and delivery. The patient was previously healthy anddid not have any predisposing factors. Increasing back painwas the only complaint. A contrast-enhanced CT study on day5 was inconclusive. Magnetic resonance imaging was performedand showed a large triangular-shaped abscess with adjacent inflammationof the paravertebral muscles. One day later, the patient developeda sensory deficit in the left lower limb. The neurological deficitcompletely resolved after surgical decompression and debridement,which was followed by antibiotic treatment. Br J Anaesth 2004; 92: 896–8     

The coiling length of thoracic epidural catheters: the influence of epidural approach angle

BACKGROUND: Thoracic epidural catheters are used for anaesthesia and postoperativeanalgesia. Usually, epidural catheters are placed without confirmationof their position despite frequent reports of complicationsas a result of malposition. In this study, we evaluated thethreading length of thoracic epidural catheters without coilingand assessed the influence of two different epidural approachangles on the threading length without coiling. METHODS: Eighty-three patients scheduled for thoracotomy were enrolledand randomly allocated into the acute angle group and the obtuseangle group. In both groups, skin insertion was performed atthe T8–9 intervertebra level. Epidural access was performedunder fluoroscopy using a paramedian approach at the T7–8level in the acute angle group and at the T6–7 level inthe obtuse angle group, and an end-hole 19-gauge epidural catheterwas inserted. Coiling length, defined as the length of the catheterwithin the epidural space when any part of the catheter justbegins to head caudally, was measured in both groups. RESULTS: The coiling length was 7.4(4.4) cm (95% CI 6.0–8.7 cm)in the obtuse angle group compared with 4.9(3.3) cm (95%CI 3.8–6.0 cm) in the acute angle group (P = 0.005). CONCLUSIONS: Approaching the thoracic epidural space with an obtuse approachangle provides longer coiling length. We recommend that an obtuseapproach angle should be used to maximize the chance of thecatheter reaching the intended level with minimum risk of coiling.     

Subcutaneous effusion resulting from an epidural catheter fragment

The breakage of an epidural catheter within a patient is uncommon,but troublesome, complication of epidural block, and its causeis rarely discovered. In this case report, our aim was to presentan effusion between s.c. tissue and fascia in the lumbar regionbecause of a broken fragment of epidural catheter which wasunnoticed during its removal.     

Recurrent post-partum seizures after epidural blood patch

There are many causes for headaches after childbirth. Even thoughpostdural puncture headache (PDPH) has to be considered in awoman with a history of difficult epidural anaesthesia, pre-eclampsiashould always be excluded as an important differential diagnosis.We report a case with signs of late-onset pre-eclampsia whereadministration of an epidural blood patch (EBP) was associatedwith eclampsia. A hypothetical causal relationship between theEBP and seizures was discarded on the basis of evidence presentedin this report. Br J Anaesth 2003; 90: 247–50     

Urinary catheterization in labour with high-dose vs mobile epidural analgesia: a randomized controlled trial

Background: Dense perineal block from epidural analgesia increases the riskof urinary catheterization in labour. Mobile epidurals usinglow-dose local anaesthetic in combination with opioid preservematernal mobility and may reduce the risk of bladder dysfunction.We conducted a three-arm randomized controlled trial to comparehigh-dose epidural pain relief with two mobile epidural techniques. Methods: A total of 1054 primparous women were randomized to receivehigh-dose bupivacaine, epidural analgesia (Control), combinedspinal epidural (CSE), or low-dose infusion (LDI). The requirementfor urinary catheterization during labour and postpartum wasrecorded. Both end points were pre-specified secondary trialoutcomes. Women were evaluated by postnatal interview, whentheir bladder function had returned to normal. Results: Relative to Control, more women who received mobile epiduraltechniques maintained the ability to void urine spontaneouslyat any time (Control 11%, CSE 31% and LDI 32%) and throughoutlabour (Control 3.7%, CSE 13% and LDI 14%), for both mobiletechniques P<0.01. There was no difference in the requirementfor catheterization after delivery. Women in the CSE group reporteda more rapid return of normal voiding sensation, relative tohigh-dose Control (P=0.02). Conclusions: Relative to conventional high-dose block, mobile epidural techniquesencourage the retention of normal bladder function and reducethe risk of urinary catheterization in labour.     

Block of the sacral segments in lumbar epidural anaesthesia

Background. Block of the first sacral segment is often delayedin lumbar epidural anaesthesia. The addition of either epinephrineor sodium bicarbonate to the local anaesthetic enhances theefficacy of epidural block. We assessed the block of lumbo-sacralsegments in lumbar epidural anaesthesia adding epinephrine and/orbicarbonate to lidocaine. Methods. Twenty-seven patients undergoing lumbar epidural anaesthesiawith lidocaine 2%, 17 ml at L4-5 or L5-S1 were randomly dividedinto three groups. Plain lidocaine, lidocaine with 1:200 000epinephrine or lidocaine–epinephrine–bicarbonatewas administrated via an epidural catheter. The pain thresholdafter repeated electrical stimulation was used to assess thesensory block at the L2, S1, and S3 segments. Motor block wasevaluated using the Bromage scale. Results. Patient characteristics were comparable between thegroups. The pH of lidocaine in the lidocaine–epinephrine–bicarbonategroup was significantly higher than that in other groups. Painthresholds at the S1 and S3 segments in the lidocaine–epinephrine–bicarbonategroup were significantly higher than those in the lidocaine–epinephrinegroup. However, differences in the pain threshold at the L2segment between groups were insignificant. The time to onsetof sensory block at the S1 and S3 in the lidocaine–epinephrine–bicarbonategroup was significantly shorter than that in the lidocaine group.Pain threshold by pinprick test was approximately within the30–50 mA range. Conclusion. A combination of lidocaine, bicarbonate, and epinephrineincreases the pain threshold over the sacral segments. Br J Anaesth 2003; 90: 173–8     

Bacterial meningitis following combined spinal–epidural analgesia for labour

We report a case of Streptococcus salivarius meningitis following combined spinal–epidural analgesia for labour. Although rare, bacterial meningitis following combined spinal–epidural anaesthesia is being increasingly described. We review the previously reported cases and discuss the possible aetiological causes and the aseptic precautions likely to reduce the incidence of infectious complications.     

Intrapartum epidural catheter migration: a comparative study of three dressing applications

We compared three types of catheter fixation application fortheir ability to minimize the incidence and magnitude of epiduralcatheter movement during labour. Patients were randomized tohave their epidural catheter secured by a Tegaderm dressing(group T; n=35), a Tegaderm dressing plus filter-shoulder fixation(group F; n=39), or a Niko Epi-Fix dressing (group N; n=37).The length of catheter visible at the patient’s skin surfacewas recorded (to the nearest 0.5 cm) after insertion and beforeremoval; the difference was defined as ‘catheter movement’.Outward movement of the catheter was greatest when a Niko Epi-Fixwas used (P<0.01). Concerning minimization of displacementof the epidural catheter per se, only a Tegaderm dressing withadditional filter-shoulder fixation proved more effective thanusing a Niko Epi-Fix dressing (P<0.05). Br J Anaesth 2001; 86: 565–7     

Effect of peri- and postoperative epidural anaesthesia on pain and gastrointestinal function after abdominal hysterectomy

In a double blind study we have investigated the effects ofepidural local anaesthesia (LA), when added to general anaesthesia(GA) and postoperative paracetamol and NSAID, on postoperativepain and gastrointestinal function in patients undergoing openhysterectomy. Sixty patients were randomized into three studygroups: GA, and postoperative paracetamol and NSAID (GA, n=20);GA, paracetamol, NSAID, intraoperative epidural lidocaine and24-h postoperative epidural saline (Saline, n=20); or GA, paracetamol,NSAID, intraoperative epidural lidocaine and 24-h postoperativeepidural bupivacaine (Bupi, n=20). Patients were observed for72 h postoperatively. Pain at rest, during cough, and mobilization,request for supplementary morphine, and time to first postoperativeflatus, was reduced in patients receiving 24-h postoperativeepidural anaesthesia, compared with the two other groups. However,these effects of epidural LA, were not sustained beyond theperiod of infusion, and no differences in PONV, time to firstpostoperative defecation, mobilization or time to dischargefrom hospital were observed between groups. A 24 h postoperativeepidural infusion with bupivacaine, when added to postoperativeparacetamol and NSAID, reduces pain and opioid requirements,but has only limited effects on gastrointestinal function andpatient recovery. Br J Anaesth 2001; 87: 577–83     

Optimal concentration of epidural fentanyl in bupivacaine 0.1% after thoracotomy

Background. The aim of this prospective, double-blind, randomizedcontrolled trial was to investigate the analgesic and adverseeffects of three commonly used concentrations of thoracic epiduralfentanyl with bupivacaine in patients undergoing thoracotomyfor lung resection. Methods. We studied 99 patients who were randomized to receivefentanyl 2 µg ml^–1 (group 2), fentanyl 5 µgml^–1 (group 5) and fentanyl 10 µg ml^–1 (group10) in bupivacaine 0.1% via a thoracic epidural. Postoperatively,pain on coughing was assessed using a visual analogue scale(VAS) and an observer verbal rating score (OVRS) at 2, 8, 16and 24 h. At the same times, sedation, pruritus and nausea wereassessed. Results. Of 29, 28 and 32 patients who completed the study ingroups 2, 5 and 10 respectively, there was no significant differencein baseline characteristics between the three groups. The numberof patients with episodes of unsatisfactory pain, i.e. VAS scores>30 mm and OVRS >1, at each of the four assessments postoperativelywas significantly (P<0.01) higher in group 2 than in groups5 and 10. In group 10, 16 patients had sedation scores >1compared with 10 each in groups 2 and 5. In addition, 19 patientsin group 10 experienced pruritus compared with 12 each, in groups2 and 5. These differences were not significant. Nausea wasnot significantly different between the three groups. Conclusion. We conclude that thoracic epidural fentanyl 5 µgml^–1 with bupivacaine 0.1% provides the optimum balancebetween pain relief and side effects following thoracotomy. Br J Anaesth 2004: 92: 670–4     

Oesophageal Doppler monitoring overestimates cardiac output during lumbar epidural anaesthesia

Oesophageal Doppler monitoring (ODM) has been advocated as anon-invasive means of measuring cardiac output (CO). However,its reliance upon blood flow measurement in the descending aortato estimate CO is susceptible to error if blood flow is redistributedbetween the upper and lower body. We hypothesize that lumbarepidural anesthesia (LEA), which causes blood flow redistribution,causes errors in CO estimates. We compared ODM with thermodilution(TD) measurements in fourteen patients under general anaesthesiafor radical prostatectomy, who had received an epidural catheterat the intervertebral level L2–L3. Coupled measurementsof CO by means of the TD and ODM techniques were performed atbaseline (general anaesthetic only) and after epidural administrationof 10 ml of 0.25% bupivacaine. The two methods were comparedusing Bland-Altman analysis: before LEA there was a bias of–0.89 litre min^–1 with limits of agreement rangingbetween –2.67 and +0.88 litre min^–1. Following lumbarsympathetic block, bias became positive (+0.55 litre min^–1)and limits of agreement increased to –3.21 and +4.30 litremin^–1. ODM measured a greater increase in CO after LEA(     

Efficacy of spray disinfection with a 2-propanol and benzalkonium chloride containing solution before epidural catheter insertion--a prospective, randomized, clinical trial

Background. Skin disinfection before neuroaxial blockade proceduresis usually obtained with sterile swabs impregnated in disinfectant.Spray disinfection is also an option which is frequently usedin minor invasive procedures. The purpose of our study was tocompare the efficacy of conventional swab disinfection withspray disinfection prior to epidural catheterization. Methods. Seventy patients who requested epidural analgesia wererandomly selected. The first group (n=35) received disinfectionwith swabs (SW) containing 2-propanol and benzalkonium chloride.The other 35 patients received spray (SP) disinfection withthe same solution. Three microbiological cultures were obtained:one culture prior to skin disinfection, a second immediatelyafter disinfection and a third from the tip of the epiduralcatheter upon removal. Results. One patient in the SW group had a positive skin cultureimmediately after the disinfection with a very low number ofcolony forming units. The other skin culture specimens wereall sterile in both groups. The colonization rate of catheterswas not statistically different between the groups at removal. Conclusion. In this study, spray disinfection was equally efficaciouscompared with the conventional skin disinfectant technique.Our results support the routine use of this simple and cheapalternative method of skin disinfection before epidural anaesthesia.     

Measuring the quality of continuous epidural block for abdominal surgery

Background. In view of the wide variation in pain experiencebetween patients, a clinical standard—the time from theend of surgery to the first experience of pain—was appliedto 1359 consecutive patients in order to investigate whetherthe initial quality of epidural block has an effect on the overallquality of postoperative pain relief. Methods. Clinical data were recorded in 58 118 out of 72 412h in 1359 patients, and transferred to a database. Data collectedincluded pain scores on a four-point verbal rating scale; nauseaand vomiting; motor block; sedation scores; systolic blood pressure<100 and <90 mm Hg; ventilatory frequency <10 and <8bpm; and hourly epidural infusion rate. Results. As the time to first experience of pain increased fromnil to >24 hours, the time from the first to last experienceof pain shortened from 34 (19–50) h to 3 (1–12)h (p<0.001) and the proportion of patients receiving an epiduralbolus decreased from 53 to 8% (p<0.001). Increases in theinitial pain free time increased the proportion of patientswith systolic BP<100 mmHg from 59 to 77%, (p<0.001) andincreased the proportion of patients with respiratory rate <10bpm from 13 to 26%, (p<0.001). Conclusion. Extending pain relief for more than 12 h beyondthe end of abdominal surgery significantly improves the overallquality of postoperative pain relief, but is associated withan increase in side-effects. ¹Present address: John Radcliffe Hospital, Oxford, UK. ²Present address: Royal Hospital for Sick Children, Edinburgh,UK     

Cerebrospinal fluid-cutaneous fistula and pseudomonas meningitis complicating thoracic epidural analgesia

We report a case of delayed cerebrospinal fluid-cutaneous fistulathat developed in a patient following removal of a thoracicepidural catheter used for perioperative analgesia. It was furthercomplicated by the development of bacterial meningitis. Predisposingfactors and management of this rare iatrogenic complicationare discussed and the literature reviewed for similar reports. Br J Anaesth 2004; 92: 429–31     

Effect of epidural bupivacaine vs combined epidural bupivacaine and morphine on gastrointestinal function and pain after major gynaecological surgery

In a double-blind study, we investigated the effects of postoperativeepidural local anaesthetic, with or without addition of epiduralmorphine, on postoperative pain and gastrointestinal functionin patients scheduled for radical hysterectomy and pelvic lymphadenectomy.Forty patients were randomized into two study groups: 48-h postoperativeepidural 0.2% bupivacaine 8 ml h^–1 (bupi group)or 48-h postoperative epidural 0.2% bupivacaine/morphine 50µg at 4 ml h^–1 (bupi/morph group). Patients wereobserved for at least 96 h after surgery. No differencesin pain at rest, during cough or mobilization were observed.Patients in the bupi group requested a significant greater amountof supplementary analgesics, but times to first flatus and defaecationwere reduced compared with patients in the bupi/morph group.Itching was a significant problem in patients in the bupi/morphgroup. No differences in postoperative nausea and vomiting,mobilization or time to discharge from hospital were observedbetween groups. The addition of morphine to postoperative epiduralbupivacaine has only limited effect on pain relief and increasestime to normalization of gastrointestinal function. Br J Anaesth 2001; 87: 727–32     

Epidural analgesia compared with peripheral nerve blockade after major knee surgery: a systematic review and meta-analysis of randomized trials

The relative analgesic efficacy and side-effect profile of peripheral nerve blockade (PNB) techniques compared with lumbar epidural analgesia for major knee surgery is unclear. We undertook a systematic review and meta-analysis of all randomized trials comparing epidural analgesia with PNB for major knee surgery. Eight studies were identified that had enrolled a total of 510 patients of whom 464 (91%) had undergone total knee joint replacement. All were small trials and none was blinded (Jadad score 1-3). PNB technique was variable: in addition to a femoral catheter (n=5), femoral single shot (n=2), or lumbar plexus catheter (n=1) techniques, sciatic blockade was performed in three trials. There was no significant difference in pain scores between epidural and PNB at 0-12 or 12-24 h, WMD 0.22 (95% CI: -0.36, 0.81), 0.05 (-1.01, 0.91), respectively, and no clinically significant difference at 24-48 h, WMD -0.35 (-0.64, -0.02). There was also no difference in morphine consumption (mg) at 0-24 h, WMD -6.25 (-18.35, 5.86). Hypotension occurred more frequently among patients who received epidurals [OR 0.19 (0.08, 0.45)], but there was no difference in the incidence of nausea and vomiting. Two studies reported a higher incidence of urinary retention in the epidural group. Patient satisfaction was higher with PNB in two of three studies which measured this, although rehabilitation indices were similar. PNB with a femoral nerve block provides postoperative analgesia which is comparable with that obtained with an epidural technique but with an improved side-effect profile and is less likely to cause a severe neuraxial complication.     

Randomized study of intravenous fluid preload before epidural analgesia during labour

We performed a randomized controlled trial of the effect ofintravenous fluid preload on maternal hypotension and fetalheart rate (FHR) changes in labour after the first epiduralinjection. Group 1 (49 women) received 1 litre of crystalloidpreload. Group 2 (46 women) received no preload. No statisticallysignificant difference was shown between the two groups foreither of the outcomes. Hypotension was found in three womenin group 1 and five in group 2 (P=0.4). Deterioration in FHRpattern was found in four women in group 1 and 11 in group 2(P=0.08). This study has not shown a significant increase inthe incidence of hypotension when intravenous preload is omittedbefore epidural analgesia using a low concentration of bupivacaineduring labour. Because of the clinical importance of the differencein the rate of FHR deterioration between the two groups, wecontinue to administer preload for high-risk cases. Br J Anaesth 2000; 85: 311–3 Footnotes ^* Correspondingauthor