A comparison of Espocan and Tuohy needles for the combined spinal-epidural technique for labor analgesia

When using the needle-through-needle combined spinal-epidural (CSE) technique for labor analgesia, failure to obtain cerebrospinal fluid (CSF), paresthesias, and intrathecal or intravascular migration of the catheter are of concern. Epidural needles with spinal needle apertures, such as the back-hole Espocan (ES) needles, are available and may reduce these risks. We describe the efficacy and adverse events associated with a modified epidural needle (ES) versus a conventional Tuohy needle for CSE. One-hundred parturients requesting labor analgesia (CSE) were randomized into 2 groups: 50-ES 18-gauge modified epidural needle with 27-gauge Pencan atraumatic spinal needle, 50-conventional 18-gauge Tuohy needle with 27-gauge Gertie Marx atraumatic spinal needle. Information on intrathecal or intravascular catheter placement, paresthesia on introduction of spinal needle, failure to obtain CSF through the spinal needle after placement of epidural needle, unintentional dural puncture, and epidural catheter function was obtained. No intrathecal catheter placement occurred in either group. Rates of intravascular catheter placement and unintentional dural puncture were similar between the groups. Significant differences were noted regarding spinal needle-induced paresthesia (14% ES versus 42% Tuohy needles, P = 0.009) and failure to obtain CSF on first attempt (8% ES versus 28% Tuohy needles, P < 0.02). Use of ES needles for CSE significantly reduces paresthesia associated with the insertion of the spinal needle and is associated with more frequent successful spinal needle placement on the first attempt. IMPLICATIONS: The use of modified epidural needles with a back hole for combined spinal-epidural technique significantly reduces paresthesia associated with the insertion of the spinal needle and is associated with more frequent successful spinal needle placement on the first attempt.     

Comparison of technical and block characteristics of different combined spinal and epidural anesthesia techniques

BACKGROUND AND OBJECTIVES: The combined spinal and epidural (CSE) technique can reduce or eliminate some of the disadvantages of spinal and epidural anesthesia, while still preserving their advantages. CSE anesthesia is now commonly performed with a single-segment needle-through-needle technique; however, this technique involves some controversies about needle handling and the risk of catheter migration. To avoid some of these potential problems, special CSE sets have been produced. In the present study, 2 of these sets were compared with the traditional double-segment technique. METHODS: Ninety patients undergoing orthopedic surgery of the lower extremity were randomly allocated into 3 groups of equal size: Group 1, CSE set with an interlocking device between the spinal and epidural needle; group 2, CSE set with a "backeye" at the epidural needle curve for the passage of the spinal needle; group 3, double-segment technique. All epidural needles were 18-gauge, and spinal needles were 27-gauge with a pencil-point tip. In groups 1 and 2, the puncture was performed at the L3-4 interspace, and in group 3 the epidural catheter was first inserted at the L2-3 interspace followed by spinal puncture one interspace lower. Hyperbaric 0.5% bupivacaine, 2 mL, was used for the spinal block, and 4 mL of 2% lidocaine with epinephrine through the epidural catheter was used as a test dose. The block performance characteristics were recorded, and the level of analgesia was studied in a blinded fashion. Postoperatively, a bolus of epidural morphine 2 to 4 mg was used for the control of postoperative pain. All patients were interviewed on the 1st and the 7th postoperative days. Afterwards, the needles and catheters were examined by microscopy. RESULTS: The frequency of the successful CSE block was higher in groups 3 (100%) and 2 (90%) than in group 1 (63%) (P <.05). The mean duration of successful block performance, as well as the median level of analgesia, were similar in all the groups. One case of epidural catheter migration intrathecally was observed (group 1). Postoperative nausea and vomiting occurred in 23% of patients, and the incidence of postdural puncture headache was 2.2%. The incidence of backache at the puncture site was similar in the groups. Microscopy showed 6 distorted spinal needle tips (all in group 1), but no material damage to the epidural catheters. CONCLUSIONS: The use of the CSE sets does not seem to save time compared with the double-segment technique. Technical problems, unsuccessful CSE block, and damaged spinal needle tip were noted relatively often with the interlocking CSE set. Anesthetic characteristics in the successful blocks were similar with the different techniques.     

Kombinierte Spinal-Epidural-Anästhesie und Läsionen des Epiduralkatheters

BACKGROUND: The purpose of this study was to investigate whether there is a risk of epidural catheter damage during the advancement of the spinal needle through an epidural needle in clinical use.METHODS: A total of 100 catheters (50 from CSE kits with a pencil-point type spinal needle and 50 from CSE kits with a Quincke type spinal needle) which had been used for routine CSE blocks were microscopically examined for any defects within the first 150 mm of the catheter. Additionally 10 unused new catheters were investigated.RESULTS: Among 10 unused catheters 5 slight scratches were found, 92 out of 100 used catheters did not show any signs of use or scratches, 7 showed some signs of use and longitudinal scratches whereas another 1 showed a moderate scratch of less than 25% of the wall thickness. There was no difference in the prevalence of scratches between the CSE kits with pencil-point type spinal needles compared to those with Quincke-type spinal needles.CONCLUSION: The CSE technique with either pencil-point type or Quincke-type spinal needles for subarachnoidal punctures was safe and showed no relevant epidural catheter damage.     

Post dural puncture headache following combined spinal epidural or epidural anaesthesia in obstetric patients.

A retrospective review of obstetric anaesthesia charts was performed for all parturients receiving regional anaesthesia over a 22-month period. The incidence of headache, post dural puncture headache (PDPH) and various other complications of regional anaesthesia that had been prospectively assessed were noted, as was the anaesthetic technique used (epidural or combined spinal epidural (CSE)). PDPH was rare (0.44%) and occurred with similar frequency in those managed with either epidural or CSE anaesthesia or analgesia. The pencil-point spinal needle gauge (27 or 29) did not influence the incidence of PDPH. Following a CSE technique, the epidural catheter more reliably produced effective analgesia/anaesthesia as compared with a standard epidural technique (1.49% versus 3.18% incidence of replaced catheters respectively). We conclude, based on the results of this retrospective review, that CSE is acceptable with respect to the occurrence of PDPH and that it is possible it is advantageous in relation to the correct placement of the epidural catheter     

Eine atraumatische Kanüle für die kontinuierliche Peridural- und Plexusanästhesie

The needle type introduced by Edward Tuohy for continuous spinal anaesthesia in 1944 is still used as the standard instrument for epidural anaesthesia up to the present day. Puncture of the dura and severance of the epidural catheter are the typical, though rare, complications of this procedure, giving rise to most of the actions brought for damage suffered during obstetic anaesthesia. The cerebral spinal fluid loss caused by thick needles can have serious consequences, including subdural and intracranial haematoma, cranial nerve pareses, labyrinthine hearing impairments and pneumocephalus. Special Sprotte needle for catheter introduction. In spinal anaesthesia and lumbar puncture the Sprotte needle has proven a very suitable instrument for prevent the CSF loss syndrome and, to a large degree, post-spinal headaches. To adapt the atraumatic properties of this needle point for epidural anaesthesia, the needle has been equipped with a plastic ramp to direct catheter insertion, and the opening geometry has been slightly modified for epidural application (see Fig.?1). The lateral catheter channel projects into the base of the needle point, which is thus shortened, and the edges of the needle opening are rounded so that the catheters cannot be severed. This needle bears the type designated ?Special Sprotte needle“ (EP no. 271715, USP no. 4842585). Needle diameter and application fields. The 1.1-mm (19.5?G) needle with 23-G catheter was introduced for epidural anaesthesia and continuous plexus anaesthesia at the Würzburg University Hospital and has proven itself in routine clinical practice. A 20-G version is being tested with a 25-G catheter for continuous spinal anaesthesia at several centers in USA, because finer spinal catheters are not permitted there by the FDA. For continuous spinal anaesthesia this needle has been available without the modified opening geometry since 1989 in sizes 22 G and 24 G and is wide by used in Europe. CSE technique with special and standard Sprotte needles. Spinal analgesia or anaesthesia (combined spinal-epidural anaesthesia) can be performed with the special needle and 123-mm-long 27 G or 29 G standard Sprotte needles before placement of the peridural catheter.     

Spinal epidural anaesthesia

We present our experience with a new combined spinal epidural system through which regional anaesthesia was performed in 30 male patients undergoing suprapubic prostatectomy. The technique consists of two needles, a 17 G Tuohy needle with a hole in its distal curve (back eye) and a 29 G spinal needle which is passed through the back eye before being introduced into the subarachnoid space. We found the back eye combined spinal-epidural system effective and simple to use. The Tuohy needle with its back eye did not impede insertion of the epidural catheter and was a suitable introducer for the thin 29 G spinal needle.     

The reuse of 29-gauge spinal needles following combined spinal-epidural anesthesia]

The technique of combined spinal epidural anaesthesia (CSE) combines the versatility of spinal with the variability of epidural anaesthesia. Spinal application of the local anaesthetic achieves a fast response, reliable sensorial and motor block at a low dose with little toxicity. The epidural catheter allows for the duration of surgical anaesthesia to be extended and provides analgesia for the postoperative period. As the incidence of post dural puncture headache (PDPH) is inversely related to the size of the spinal needle, PDPH rarely or never occurs when 29 gauge needles are used. In 1775 parturients receiving spinal anaesthesia for caesarean section, Dittmann et al. [4] reported an incidence of PDPH of 1.37% with 29 gauge needles. The 29 gauge needle produced by Becton-Dickinson is the one now most frequently used for this technique. It is recommended that these needles be reused after resterilization. The objective of this study was to examine how clean 29 gauge spinal needles really are after resterilization. MATERIALS AND METHODS. Fifteen needles (29 gauge; Becton-Dickinson) were routinely used for combined spinal epidural anaesthesia. After identification of the epidural space at the L3-4 spinal segment with the 18 gauge Tuohy needle, the 29 gauge needle was advanced through the Tuohy needle. Immediately after use the needles were cleaned, rinsed with 20 ml distilled water, dried with pressurized air and subsequently resterilized in gas. Preparation of the used needles was in accordance with the manufacturer's recommendations ("wash, rinse, dry, sterilize before initial and each subsequent use") and with generally accepted principles [6]. Two needles were additionally cleaned in an ultrasonic bath for 15 min. The needles were examined using a scanning electron microscope. After this analyses, eight needles were sterilized again and then taken for hygienic examination. They were incubated with trypticase soy broth and checked for bacterial growth. RESULTS. Scanning electron microscopy (ScEM) showed organic impurities on all needles. These impurities were equally distributed among all needles. Even the two cleaned in the ultrasonic bath were not free of organic particles. However, no material defects or damage could be seen. Hygienic evaluation proved sterility as no bacterial growth could be detected. CONCLUSION. Owing to the possibility of medico-legal consequences, which sometimes occur a long time after anaesthesia has been given, we think it is unwise to reuse such needles. We hope that disposable and cheap 29 gauge needles will soon become available.     

Paraesthesia during the needle-through-needle and the double segment technique for combined spinal epidural anaesthesia

Paraesthesia during regional anaesthesia is an unpleasant sensation for patients and, more importantly, in some cases it is related to neurological injury. Relatively few studies have been conducted on the frequency of paraesthesia during combined spinal epidural anaesthesia. We compared two combined spinal epidural anaesthesia techniques: the needle-through-needle technique and the double segment technique in this respect. We randomly allocated 116 parturients undergoing elective Caesarean section to receive anaesthesia using one of these techniques. Both techniques were performed using a 27G pencil point needle, an 18G Tuohy needle, and a 20G multiport epidural catheter from the same manufacturer. The overall frequency of paraesthesia was higher in the needle-through-needle technique group (56.9% vs. 31.6%, p = 0.011). The frequency of paraesthesia at spinal needle insertion was 20.7% in the needle-through-needle technique group and 8.8% in the double segment technique group; whereas the frequency of paraesthesia at epidural catheter insertion was 46.6% in the needle-through-needle technique group and 24.6% in the double segment technique group.     

Combined spinal epidural anaesthesia: a new technique

A new technique is described for delivering combined spinal epidural anaesthesia. The disadvantages of the needle-through-needle technique and the two-needle techniques are discussed. The new technique is a modification of the two-needle technique. The spinal needle is introduced and once cerebrospinal fluid is seen at the hub of the needle, the stylet is replaced. The epidural space is then identified and the epidural catheter placed. The spinal needle obturator is then removed and intrathecal injection performed. This technique avoids problems associated with placing an epidural catheter after an intrathecal injection and the potential problem of placing a spinal needle when an epidural catheter has already been placed. This technique requires further evaluation.     

Combined epidural/spinal anaesthesia for Caesarean section

An evaluation of a 30 gauge spinal needle in a combined epidural/spinal anaesthetic technique for Caesarean section revealed a 25% failure rate of the spinal element. In this unit, no more than 4% of spinal anaesthetics might be expected to fail. One of the reasons for the higher failure rate was that, when using the Tuohy needle as an introducer, the dura was not identified. This prompted us to compare the 'through-the-Tuohy' or needle within needle approach for combined epidural/spinal anaesthesia, with a technique that involved siting the epidural and spinal sequentially in separate spaces. One hundred women requiring elective Caesarean section under spinal anaesthesia were randomised into single or double space groups. The technique failed in 16% of through-the-needle cases, and in 4% of sequential sitings. Combined spinal/epidural anaesthesia for Caesarean section is more successful if each procedure is performed using separate spaces.     

Sensorimotor anesthesia and hypotension after subarachnoid block: combined spinal-epidural versus single-shot spinal technique

The extent of the intrathecal compartment depends on the balance between cerebrospinal fluid and subatmospheric epidural pressure. Epidural insertion disrupts this relationship, and the full impact of loss-of-resistance on the qualities of subarachnoid block is unknown. In this study we sought to determine if subarachnoid block, induced by combined spinal-epidural (CSE) using loss-of-resistance to air could render higher sensory anesthesia than single-shot spinal (SSS) when an identical mass of intrathecal anesthetic was injected. Sixty patients, scheduled for minor gynecological procedures, were randomly allocated into three groups all receiving 10 mg of 0.5% hyperbaric bupivacaine. In the SSS group, intrathecal administration was through a 27-gauge Whitacre spinal needle inserted at the L3-4 level. For the CSE group, the epidural space was identified with an 18-gauge Tuohy needle using loss-of-resistance to 4 mL of air. After intrathecal administration, a 20-gauge catheter was left in the epidural space. No further drug or saline was administered through the catheter. The procedure was repeated in group CSE ((no-catheter)) except without insertion of a catheter. Sensorimotor anesthesia was assessed at regular 2.5-min intervals until T10 was reached. In all aspects, there was no difference between CSE and CSE ((no-catheter)). Peak sensory level in SSS was lower than CSE and CSE ((no-catheter)) (median T5 [max T3-min T6] versus (T3 [T1-4] and (T3 [T2-5]) (P < 0.01). During the first 10 min postblock, dermatomal thoracic block was the lowest in SSS (P < 0.05). Time for regression of sensory level to T10 was also shortest in SSS. Hypotension, ephedrine use and period of motor recovery were more pronounced in CSE and CSE ((no-catheter)). We conclude that subarachnoid block induced by CSE produces greater sensorimotor anesthesia and prolonged recovery compared with SSS. There is also a more frequent incidence of hypotension and vasoconstrictor use despite using identical doses and baricity of local anesthetic. IMPLICATIONS: This study confirms that induction of subarachnoid block by a combined-spinal epidural technique produces a greater sensorimotor anesthesia and results in prolonged recovery when compared with a single-shot spinal technique. There is a more frequent incidence of hypotension and vasoconstrictor administration despite identical doses of intrathecally administered local anesthetic.     

Combined spinal-epidural anesthesia for cesarean section; needle-through-needle approach

Purpose The Portex “Spinal/Epidural Set” is designed for combined spinal-epidural (CSE) anesthesia by the needle-through-needle approach. We evaluated the technical and clinical usefulness of CSE with this needle set, and also isobaric tetracaine, for cesarean section. Methods Thirty patients for cesarean section were included. In the left decubitus position, a 16-gauge epidural needle was introduced by the loss-of-resistance method into the lumbar intervertebral space. A 26-gauge spinal needle was threaded through the epidural needle into the subarachnoid space. Tetracaine dissolved in saline was injected. A 17-gauge catheter was advanced into the epidural space. The analgesic level was checked by the pin-prick method. Results The insertion in the first attempt was successful in 21 cases (70%) of the patients, and difficulty in insertion was not experienced. Inadvertent dural puncture occurred in one case, but no accidental subarachnoid catheterization was observed. Spinal anesthesia with tetracaine (11.1±0.5 mg) reached the level of Th₆ on average, with a relatively wide range. Five cases (13%) were supplemented by epidural anesthesia. No postspinal headache was noted. Conclusion CSE technique by the needle-through-needle approach is easy to handle, and provides a speedy, reliable, and flexible analgesia as well as postoperative pain relief for patients undergoing cesarean section.     

Combined spinal epidural anaesthesia: the single space double-barrel technique

We present our own single-space method for performing combined spinal epidural anaesthesia. A spinal introducer and a Tuohy needle are sited in the same interspace. After insertion of the epidural catheter the introducer is used as a guide for a 25 gauge spinal needle. The advantages of this technique over other methods are explored. A series of 90 patients who received combined spinal epidural anaesthesia for elective Caesarean section is presented. The incidence of side effects (hypotension, nausea and vomiting, itching, post dural puncture headache) was comparable with those of other series. However, a high incidence (26.6%) of paraesthesiae during insertion of the spinal needle was noted. We suggest that this finding may be related to the use of pencil-point needles.     

Detection of epithelial cell transfer in spinal areas by light microscopy and determining any tissue coring via cell culture during combined spinal-epidural interventions

BACKGROUND AND OBJECTIVES: Epithelial tissue coring by spinal needles during subarachnoid injections may cause intraspinal epidermal tumors. Previous studies have investigated tissue transfer with different needle types during subarachnoid or epidural injection. This study deals with the transfer of epithelial tissue during combined spinal-epidural (CSE) anesthesia. METHODS: We studied 68 American Society of Anesthesiologists I to III adult patients. CSE anesthesia was induced under aseptic conditions at the L2-3 or L3-4 interspace with patients in the lateral decubitus position. Cerebral spinal fluid, spinal needle stylet, fluid used to flush the interior of the spinal needle, fluid used to wash the exterior of the spinal needle, fluid used to flush the interior of the epidural needle, and fluid used to wash the exterior tip of the epidural needle were examined under light microscopy (n = 30 patients) or incubated in a cell-culture medium (n = 38 patients). Samples were incubated in cell-culture medium alone (n = 13) or in a cell-culture medium for 3 weeks and then in a medium with epidermal growth factor (n = 25). As a positive control, skin tissue samples were taken by punch biopsy from 10 randomly chosen patients who underwent CSE interventions. These samples were incubated in an enriched medium serum. RESULTS: Light microscopy revealed that there was cell transfer in all phases in various rates: samples 1, 2, 3, 4, 5, and 6 contained epithelial cells and debris in ratios of 6.9%, 20.7%, 6.9%, 20.7%, 26.7%, and 33.3%, respectively. Epithelial cell colonization was detected in the cell-culture samples taken from the control group but not in the samples taken from the CSE group. CONCLUSIONS: We could not reproduce the cells or cell debris obtained during the CSE interventions in vivo, which can be explained by a possible structural deformation of cells or the inadequacy of the amount of cells that were transferred.     

A survey of anaesthetic techniques used for caesarean section in the UK in 1997

A prospective survey of anaesthesia for caesarean section was performed for the year 1 January to 31 December, 1997. Two hundred and fifty maternity hospitals were sent questionnaires from which 129 responses were obtained. The data provided information on anaesthesia for 60 455 caesarean sections. Overall 78% of sections were performed with regional anaesthesia: 47% single shot spinal; 22% epidural; 9% combined spinal epidural (CSE); 22% general anaesthesia. For elective caesarean sections (39% of all sections) regional anaesthesia was used for 87% of cases: 68% single shot spinal; 3% epidural; 15% CSE; 13% general anaesthesia. For emergency procedures regional anaesthesia was used for 72% of cases: 34% single shot spinal; 34% epidural; 4% CSE; 28% general anaesthesia. There was a wide range of regional anaesthesia use among the units, varying from an overall rate of 95% at one extreme to 41% at the other. Similarly, there was a wide range of conversion of regional anaesthesia to general anaesthesia, varying from 0% to 88%. Overall, 10.6% of the general anaesthetics were the result of regional to general anaesthesia conversion.     

硬膜外注气对脊椎-硬膜外联合阻滞时腰穿的影响

目的 探讨硬膜外注气对脊椎-硬膜外联合阻滞时腰穿的影响.方法 拟在脊椎-硬膜外联合阻滞下行剖宫产术的足月单胎妊娠患者210例,ASA分级Ⅰ或Ⅱ级,年龄20～42岁,身高152～170 cm,体重57～82 kg,采用随机数字表法,将患者随机分为3组(n=70):悬滴法组(Ⅰ组)、少量注气组(Ⅱ组)和大量注气组(Ⅲ组).Ⅰ组以悬滴法验证硬膜外腔,Ⅱ组和Ⅲ组以注气试验验证硬膜外腔.Ⅱ组注气量以能感觉到阻力消失为准,Ⅲ组注气量为4 ml.置入腰穿针后见脑脊液回流则为腰穿成功.腰穿失败则改行硬膜外麻醉.记录腰穿成功情况、腰穿失败但硬膜外穿刺成功情况及不良反应发生情况.结果 Ⅰ组、Ⅱ组和Ⅲ组腰穿成功率分别为91%、93%和79%,Ⅰ组和Ⅱ组高于Ⅲ组(P<0.05),Ⅰ组和Ⅱ组间差异无统计学意义(P>0.05).所有腰穿失败患者均取得了双侧躯体节段性痛觉消失的硬膜外麻醉效果;所有腰穿成功患者也均取得了预期的麻醉效果.均未见严重不良反应发生.结论 硬膜外注气与脊椎-硬膜外联合阻滞时腰穿成功有关,大量注气可降低腰穿成功机率.

Abstract：

Objective To investigate the effect of injection of air into the epidural space on the subarachnoid puncture during the combined spinal-epidural anesthesia (CSEA) .Methods Two hundred and ten ASA Ⅰ or Ⅱ parturients who were at full term with a singleton fetus, aged 20-42 yr, weighing 57-82 kg (height 152-170cm) , undergoing cesarean section under CSEA, were randomly divided into 3 groups ( n = 70 each) : hanging drop technique group (group Ⅰ ) and injection of small volume of air group (group Ⅱ ) and injection of large volume of air group ( group Ⅲ ) . The epidural space was indentified using hanging drop technique in group Ⅰ and using loss of resistance to air technique in Ⅱ and Ⅲ groups. Injection of air was stopped as soon as the clear loss of resistance identified the epidural space in group Ⅱ , whereas all 4 ml of air was injected in group Ⅲ . After the epidural space was confirmed at L3,4 interspace, a 25-gauge spinal needle protruding 14 mm beyond the 18-gauge epidural needle was introduced through the epidural needle. Subarachnoid placement was confirmed by backflow of cerebrospinal fluid (CSF) . If no backflow of CSF was observed, the spinal needle was withdrawn and an epidural catheter was inserted through the epidural needle to perform epidural anesthesia. Successful subarachnoid puncture, failures to observe backflow of CSF and adverse reactions were recorded. Results The three groups were comparable with respect to age, height, body weight and gestation weeks. The success rate of subarachnoid puncture was 91% ,93% and 79% in Ⅰ ,Ⅱ and Ⅲ groups respectively, and it was significantly higher in Ⅰ and Ⅱ groups than in group Ⅲ ( P < 0.05) . There was no significant difference in the success rate of subarachnoid puncture between Ⅰand Ⅱ groups ( P > 0.05) . Bilateral segmental analgesia presented in all cases who received only epidural anesthesia after no backflow of CSF was observed, and the expected analgesia also presented in all cases in whom back flow of CSF was observed. No adverse reactions occurred. Conclusion Injection of air into the epidural space is related to the success of subarachnoid puncture during CSEA and injection of a large volume of air lowers the success rate.     

The combined spinal-epidural technique

Epidural and spinal blocks are well-accepted regional techniques, but they have several disadvantages. The CSE technique can reduce or eliminate the risks of these disadvantages. CSE block combines the rapidity, density, and reliability of the subarachnoid block with the flexibility of continuous epidural block to extend duration of analgesia. The CSE technique is used routinely at many institutions, particularly for major orthopedic surgery and in obstetrics. It has been used in tens of thousands of patients without any reports of major problems. Although at first sight the CSE technique appears to be more complicated than epidural or spinal block alone, intrathecal drug administration and siting of the epidural catheter are both enhanced by the combined, single-space, needle-through-needle method. Concerns about the epidural catheter entering the theca via the small puncture hole are now considered to be unfounded, but as with all epidural catheter techniques, vigilant monitoring of the patient during and after any injection is paramount. CSE is an effective way to reduce the total drug dosage required for anesthesia or analgesia. The intrathecal injection achieves rapid onset with minimal doses of local anesthetics and opioids, and the block can be prolonged with low-dose epidural maintenance administration. In addition, the sequential CSE method can be used to extend the dermatomal block with minimal additional drugs or even saline. Reduction in total drug dosage has made truly selective blockade possible. Many studies have confirmed that low-dose CSE with local anesthetic and opioid, or low-dose epidural block alone, will provide effective analgesia with minimal motor and proprioceptive block. Such neurologic selective blockade has made it possible for most patients to walk and bear down normally in labor or postoperatively. There remains concern about the risk of infection being increased when the CSE technique is used in place of epidural block alone. Despite a recent flurry of reports of meningitis with CSE procedures, there is no evidence the CSE block is more hazardous than epidural or subarachnoid block alone. Arguably, the single-space, needle-through-needle CSE technique will continue to improve with new needle designs and other advances to improve further the success rate and reduce complications, such as neurotrauma, PDPH, and infection. Over the past decade it has become clear that the CSE technique is a significant advance in regional blockade.     

Dural puncture with a 27-gauge Whitacre needle as part of a combined spinal-epidural technique does not improve labor epidural catheter function

BACKGROUND: This prospective, double-blind, randomized study was designed to examine whether the combined spinal-epidural technique without subarachnoid drug administration improved epidural catheter function when compared with the traditional epidural technique. METHODS: After institutional review board approval and informed consent, 251 healthy laboring parturients were randomly assigned to either group DP (combined spinal-epidural technique with 27-gauge Whitacre needle dural puncture but without subarachnoid drug administration) or group NoDP (traditional epidural technique). Patient-controlled epidural analgesia was initiated with 0.11% bupivacaine and 2 microg/ml fentanyl. Top-up doses in 5-ml increments of 0.25% bupivacaine were administered if needed. Previous power analysis revealed that a sample size of 108 patients/group was needed to show a clinically useful reduction of the catheter manipulation rate from 32% to 15%. RESULTS: In groups DP and NoDP, 107 and 123 evaluable patients, respectively, completed the study. Demographics and outcome variables measured, including epidural catheter manipulation and replacement rate, sacral sparing, unilateral block, number of top-up doses, average hourly epidural drug usage, highest sensory blockade level, and labor analgesia quality, were not different between groups. A subgroup of 18 patients without cerebral spinal fluid return during dural puncture had a higher catheter replacement rate than those of groups DP and NoDP, but it did not reach statistical significance. CONCLUSIONS: Dural puncture with a 27-gauge Whitacre needle without subarachnoid drug administration during combined spinal-epidural labor analgesia did not improve epidural labor analgesia quality or reduce catheter manipulation or replacement rate when compared with a traditional epidural technique.     

Use of 29–gauge spinal needles and a fixation device with combined spinal epidural technique

One hundred patients between 15–46 years, undergoing elective surgery, were given spinal anaesthesia using 29–gauge spinal needles introduced through a Tuohy needle with a fixation device. Successful spinal anaesthesia was achieved in 98%. A success rate of 100% was achieved when a combined spinal epidural technique was used. Ninety–eight percent of the patients would prefer the same anaesthesia procedure for similar kind of surgery in the future.     

Development and current status of combined spinal epidural anaesthesia

Combined spinal and epidural anaesthesia/analgesia is a method whereby drugs are applied intrathecally as a single dose and epidurally either continuously or intermittently via an epidural catheter. More than 50 years ago, first attempts were made to introduce this method into clinical practice but they found little general acceptance. Only during the last decades has tremendous progress been made in developing new, highly-sophisticated equipment: matching spinal and epidural needles and catheters, epidural needles with a separate conduit for the spinal needle or with an additional hole for the exit of the spinal needle as well as fixation devices for the spinal needle. A specific feature of the method is the only recently recognised epidural volume extension, which allows the use of low-dose drug combinations with sufficient analgetic properties but less cardiovascular compromise and fewer side-effects. This review describes the main and most important developmental steps and offers practical examples for its use in day-case surgery of the lower limb, in the "walking epidural" in obstetrics and in caesarean section. The method has become a valuable new tool in the armamentarium of the anaesthetist and part of daily routine in many clinics.