The effect of placement and management of intrathecal catheters following accidental dural puncture on the incidence of postdural puncture headache and severity: a retrospective real-world study

Accidental dural puncture during an attempt to establish labour epidural analgesia can result in postdural puncture headache and long-term debilitating conditions. Epidural blood patch, the gold standard treatment for this headache, is invasive and not always successful. Inserting an intrathecal catheter after accidental dural puncture may prevent postdural puncture headache. We evaluated the effect of intrathecal catheter insertion on the incidence of postdural puncture headache and the need for epidural blood patch and whether duration of intrathecal catheterisation or injection of intrathecal saline affected outcome. Our retrospective study was conducted at two tertiary, university-affiliated medical centres between 2017 and 2022 and included 92,651 epidurals and 550 cases of accidental dural puncture (0.59%); 219 parturients (39.8%) received an intrathecal catheter and 331 (60.2%) a resited epidural. Use of an intrathecal catheter versus resiting the epidural did not decrease the odds of postdural puncture headache, adjusted odds ratio (aOR) (95%CI) 0.91 (0.81–1.01), but was associated with a lower need for epidural blood patch (aOR (95%CI) 0.82 (0.73–0.91), p < 0.001). We found no benefit in leaving in the intrathecal catheter for 24 h postpartum (postdural puncture headache, aOR (95%CI) 1.01 (1.00–1.02), p = 0.015; epidural blood patch, aOR (95%CI) 1.00 (0.99–1.01), p = 0.40). We found an added benefit of injecting intrathecal saline as it decreased the incidence of postdural puncture headache (aOR (95%CI) 0.85 (0.73–0.99), p = 0.04) and the need for epidural blood patch (aOR (95%CI) 0.75 (0.64–0.87), p < 0.001). Our study confirms the benefits of intrathecal catheterisation and provides guidance on how to best manage an intrathecal catheter.     

A prospective controlled study of continuous spinal analgesia versus repeat epidural analgesia after accidental dural puncture in labour

BackgroundAfter accidental dural puncture in labour it is suggested that inserting an intrathecal catheter and converting to spinal analgesia reduces postdural puncture headache and epidural blood patch rates. This treatment has never been tested in a controlled manner.MethodsThirty-four hospitals were randomised to one of two protocols for managing accidental dural puncture during attempted labour epidural analgesia: repeating the epidural procedure or converting to spinal analgesia by inserting the epidural catheter intrathecally. Hospitals changed protocols at six-month intervals for two years.ResultsOne hundred and fifteen women were recruited but 18 were excluded from initial analysis because of practical complications which had the potential to affect the incidence of headache and blood patch rates. Of the remaining 97 women, 47 were assigned to the repeat epidural group and 50 to the spinal analgesia group. Conversion to spinal analgesia did not reduce the incidence of postdural puncture headache (spinal 72% vs. epidural 62%, P = 0.2) or blood patch (spinal 50% vs. epidural 55%, P = 0.6). Binary logistic analysis revealed the relative risk of headache increased with 16-gauge vs. 18-gauge epidural needles (RR = 2.21, 95% CI 1.4–2.6, P = 0.005); anaesthetist inexperience (RR = 1.02 per year difference in experience, 95% CI 1.001–1.05, P = 0.043), and spontaneous vaginal compared to caesarean delivery (RR = 1.58, 95% CI 1.14–1.79, P = 0.02). These same factors also increased the risk of a blood patch: 16-gauge vs. 18-gauge needles (RR = 2.92, 95% CI 1.37–3.87, P = 0.01), anaesthetist inexperience (RR = 1.06 per year difference in experience, 95% CI 1.02–1.09, P = 0.006), spontaneous vaginal versus caesarean delivery (RR = 2.22, 95% CI 1.47–2.63, P = 0.002). When all patients were included for analysis of complications, there was a significantly greater requirement for two or more additional attempts to establish neuraxial analgesia associated with repeating the epidural (41% vs. 12%, P = 0.0004) and a 9% risk of second dural puncture.ConclusionsConverting to spinal analgesia after accidental dural puncture did not reduce the incidence of headache or blood patch, but was associated with easier establishment of neuraxial analgesia for labour. The most significant factor increasing headache and blood patch rates was the use of a 16-gauge compared to an 18-gauge epidural needle.     

The influence of timing on the effectiveness of epidural blood patches in parturients

BackgroundPostdural puncture headache is common in parturients following lumbar puncture. If headache is severe and persistent, an epidural blood patch is recommended. In this paper we reviewed the efficacy of epidural blood patches over a 13-year period at two hospitals in Finland with a particular emphasis on its timing.MethodsThe hospitals’ databases were searched to identify parturients who underwent an epidural blood patch from March 1998 to June 2011. Parturients’ records were reviewed to establish the characteristics and associated symptoms of headache and the effectiveness of the epidural blood patch.ResultsA total of 129 parturients received 151 epidural blood patches. These followed spinal (n = 49), epidural (n = 47) or combined spinal–epidural blocks (n = 33). The success rate of the first procedure was 89%, with permanent relief in 76%. The first procedure provided permanent relief of postdural puncture headache for 86% of 78 patients having the procedure after 48 h, compared to 65% of 37 patients when it was performed between 24 and 48 h, and 50% of 14 patients with the procedure within the first 24 h after dural puncture (P = 0.003). A second procedure was performed for 22 parturients due to incomplete relief (n = 5) or recurrent symptoms (n = 17); all had complete resolution of symptoms.ConclusionsEpidural blood patch performed later than 48 h following lumbar puncture or accidental dural puncture is effective in parturients with postdural puncture symptoms. The recurrence rate of symptoms after an initially successful epidural blood patch is high, and therefore patients should be provided with counselling and contact information.     

Nine-year audit of post-dural puncture headache in a tertiary obstetric hospital in Singapore

BackgroundThe KK Women’s and Children’s Hospital is a tertiary obstetric unit with approximately 11 000 deliveries per year. Epidural analgesia is used in about 40% of laboring women. We reviewed the incidence and management of post-dural puncture headache over a nine-year period.MethodsA retrospective audit of labor epidural analgesia database records from 1 June 2005 to 31 May 2014 was conducted, identifying an “event” as an accidental dural puncture, an inadvertent intrathecal catheter insertion and/or development of a post-dural puncture headache.ResultsA total of 43 434 epidural records were reviewed. Sixty-three events were identified (an incidence of 0.15%). Women had median age of 30 years and median body mass index of 27.6 kg/m²; 69.8% (44/63) delivered vaginally. Procedures performed by less experienced anesthesiologists and those performed outside office hours were associated with a higher incidence of accidental dural puncture. An intrathecal catheter was inserted in 52 of 58 women (89.7%). Headache developed in 24 of 38 (63.1%) women in whom there was a witnessed accidental dural puncture. Most women who developed post-dural puncture headache presented during the primary admission (36/39; 92.3%). Paracetamol and non-steroidal anti-inflammatory drugs were the most commonly prescribed medications. Six women (9.5%) received an epidural blood patch which led to resolution of headache.ConclusionA retrospective audit over a nine-year period at a tertiary teaching hospital found the overall incidence of post-dural puncture headache and associated events to be 0.15%, with a decreasing trend coinciding with improvement in the teaching and supervision of trainees in labor epidural procedures.     

The effect of second-stage pushing and body mass index on postdural puncture headache

Study objectiveTo explore how pushing during labor and body mass index affect the development of postdural puncture headache in parturients who experienced dural puncture with Tuohy needles.DesignRetrospective cohort.SettingObstetric ward and operating rooms at a university-affiliated hospital.PatientsOne hundred ninety parturients who had witnessed dural puncture with 17 or 18 gauge Tuohy needles from 1999-2014.InterventionsPatients were categorized by pushing status and body mass index (kg/m²): nonobese <30, obese 30-39.99, morbidly obese 40-49.99, and super obese ≥50.MeasurementsHeadache, number of days of headache, maximum headache score, and epidural blood patch placement.Main resultsCompared with women who did not push, women who pushed during labor had increased risk of postdural puncture headache (odds ratio [OR], 2.1 [1.1-4.0]; P = .02), more days of headache (P = .02), and increased epidural blood patch placement (P = .02). Super obese patients were less likely to develop headache compared with nonobese (OR, 0.33 [0.13-0.85]; P = .02), obese (OR, 0.37 [0.14-0.98]; P = .045], and morbidly obese patients (OR, 0.20 [0.05-0.68]; P < .01). In a multivariate logistic regression model, lack of pushing (OR, 0.57 [0.29-1.10]; P = .096) and super obesity (OR, 0.41 [0.16-1.02]; P = .056] were no longer significantly associated with reduced risk of postdural puncture headache.ConclusionsParturients who did not push before delivery and parturients with body mass index ≥50 kg/m² were less likely to develop postdural puncture headache in a univariate analysis. Similar trends were demonstrated in a multivariate model, but were no longer statistically significant.     

The relationship between body mass index and post-dural puncture headache in obstetric patients

BackgroundDifficult epidural insertion and accidental dural puncture are more likely in the obese pregnant population. Low-level evidence suggests that the risk of post-dural puncture headache declines as body mass index increases.MethodsWe retrospectively reviewed prospective data on 18 315 obstetric epidural and combined spinal–epidural insertions, identifying 125 (0.7%) accidental dural punctures or post-dural puncture headaches between 2007 and 2012. The audit record and patient medical record were examined to determine patient body mass index, headache characteristics and use of a therapeutic epidural blood patch. Women were classified into two groups: non-obese (body mass index <30 kg/m², Group <30) or obese (body mass index ⩾30 kg/m², Group ⩾30). Statistical analysis was by chi-square or Fisher exact tests, with P < 0.05 considered significant.ResultsCompared to Group <30 (n = 65), women in Group ⩾30 (n = 60) did not significantly differ in the incidence of post-dural puncture headache (82% vs 80%, P = 0.83); its intensity (severe 36% vs. 23%, P = 0.34); or the need for epidural blood patch (57% vs. 54%, P = 0.81). Groups also did not differ significantly when confining analysis to those who had a witnessed accidental dural puncture (n = 93) or to women with a body mass index >40 kg/m² (n = 10) vs. Group <30.ConclusionThis retrospective study found no evidence that women of higher body mass index are less likely to develop a post-dural puncture headache or that the characteristics of the headache and use of epidural blood patch were different.     

Accidental dural puncture,postdural puncture headache,intrathecal catheters,and epidural blood patch: revisiting the old nemesis

One of the controversial management options for accidental dural puncture in pregnant patients is the conversion of labor epidural analgesia to continuous spinal analgesia by threading the epidural catheter intrathecally. No clear consensus exists on how to best prevent severe headache from occurring after accidental dural puncture. To investigate whether the intrathecal placement of an epidural catheter following accidental dural puncture impacts the incidence of postdural puncture headache (PDPH) and the subsequent need for an epidural blood patch in parturients. A retrospective chart review of accidental dural puncture was performed at Hutzel Women’s Hospital in Detroit, MI, USA for the years 2002–2010. Documented cases of accidental dural punctures (N = 238) were distributed into two groups based on their management: an intrathecal catheter (ITC) group in which the epidural catheter was inserted intrathecally and a non-intrathecal catheter (non-ITC) group that received the epidural catheter inserted at different levels of lumbar interspaces. The incidence of PDPH as well as the necessity for epidural blood patch was analyzed using two-tailed Fisher’s exact test. In the non-ITC group, 99 (54 %) parturients developed PDPH in comparison to 20 (37 %) in the ITC [odds ratio (OR), 1.98; 95 % confidence interval (CI), 1.06–3.69; P = 0.03]. Fifty-seven (31 %) of 182 patients in the non-ITC group required an epidural blood patch (EBP) (data for 2 patients of 184 were missing). In contrast, 7 (13 %) of parturients in the ITC group required an EBP. The incidence of EBP was calculated in parturients who actually developed headache to be 57 of 99 (57 %) in the non-ITC group versus 7 of 20 (35 %) in the ITC group (OR, 2.52; 95 % CI, 0.92–6.68; P = 0.07). The insertion of an intrathecal catheter following accidental dural puncture decreases the incidence of PDPH but not the need for epidural blood patch in parturients.     

Impact of obesity on post-dural puncture headache

IntroductionPrevious studies have suggested an inverse relationship between obesity and development of post-dural puncture headache following spinal anesthesia. However, few have investigated the relationship between obesity and headaches after accidental dural puncture with an epidural needle. This study explored whether obesity has any association with headaches following an accidental dural puncture.MethodsRecords of patients who received epidural analgesia for labor and vaginal delivery between January 2011 and June 2015 were reviewed. Body mass index, American Society of Anesthesiologists Physical Status and age were analyzed. Chi-squared analysis was performed to determine the relationship between the incidence and severity of post-dural puncture headaches and body mass index.ResultsA total of 17 497 epidurals were placed for vaginal deliveries. Of these, 164 patients met our criteria for accidental dural puncture, of whom 51.2% developed post-dural puncture headaches. Of patients who developed a post-dural puncture headache 35.7% required an epidural blood patch. Data analysis showed no significant relationship between body mass index and incidence of post-dural puncture headaches regardless of body mass index classification (P>0.05). There was no association between body mass index and the intensity of post-dural puncture headache (P=0.29).ConclusionPatients with a high body mass index do not appear to be protected from experiencing a post-dural puncture headache after an accidental dural puncture during placement of labor epidural analgesia. Additionally, the intensity of post-dural puncture headache does not vary with body mass index.     

A retrospective review of an epidural blood patch database: the incidence of epidural blood patch associated with obstetric neuraxial anesthetic techniques and the effect of blood volume on efficacy

BackgroundThe optimal volume of blood required to treat post-dural puncture headache remains in question. In our institution a target volume of 30 mL is used for an epidural blood patch unless the patient experiences pain during injection.MethodsThe institutional database was retrospectively reviewed for epidural blood patch and delivery statistics over a 15-year period to determine if the volume of blood administered during the procedure directly correlated with the number of epidural blood patches administered. The primary endpoint was defined as the need for a repeat epidural blood patch.ResultsThere were 466 epidural blood patches performed on 394 patients, associated with 84 804 obstetric neuraxial procedures. Thirty-two percent (95% CI 28.3 to 34.9%) of patients who had an inadvertent dural puncture with an epidural needle received an epidural blood patch versus 0.19% (0.16% to 0.22%) of patients who received neuraxial anesthesia with no documented dural puncture with an epidural needle. All patients experienced relief of post-dural puncture headache, although 17% required two and 1.5% required three epidural blood patches. The mean ± SD volume of blood administered was 20.5 ± 5.4 mL and only 35 patients (8.9%) received 30 mL.ConclusionIncreasing blood volumes up to 30 mL did not reduce the need for repeat epidural blood patch. Although the optimal volume of blood to administer during epidural blood patch placement remains unknown, our institution will continue to administer up to 30 mL or until the patient experiences pain during epidural injection.     

Sequential higher epidural catheter re-insertion after accidental dural puncture ameliorates the frequency and severity of post-dural puncture headache

ObjectivesThis cohort study aimed to evaluate the outcome of a hypothesis to use higher level for epidural catheter insertion and activation when an epidural tap was encountered at a lower level during epidural analgesia for labor pain.MethodsEpidural analgesia for labor pain was conducted using a mixture of 0.125% bupivacaine and fentanyl 5 μg/ml (10–15 ml) in 5-ml increments and maintained using continuous epidural infusion of 0.125% bupivacaine and fentanyl 2 μg/ml at rate of (5–15 ml/h), subsequently adjusted according to the patients needs. All cases had accidental dural puncture (ADP) were managed immediately with re-insertion of the needle at a higher level and completion of the procedure and maintained using continuous epidural infusion of 0.0625% bupivacaine and fentanyl 2 μg/ml at rate of (6–12 ml/h) for 24 h after delivery. Postpartum follow-up was conducted for 30 days to comment on the occurrence and severity of post-dural puncture headache (PDPH). All patients developed PDPH were followed daily until resolution of their headache.ResultsAbout 4800 parturient were enrolled in the study, ADP occurred in 24 patients with a frequency of 0.5%. All cases were immediately managed by re-insertion of the needle at a higher level and the procedure was successfully completed without new dural puncture, with 100% re-insertion success rate, and patients were maintained on continuous epidural infusion for 24 h. Throughout 30-day follow-up; only six of 24 patients developed PDPH with a success rate of re-insertion procedure as a prophylactic modality for PDPH after ADP of 75%. PDPH was relieved with bed rest, liberal fluids and paracetamol for 4 days in four patients, while the 5th patient continued to complain but the patient refused to undergo epidural blood patch (EBP) and headache started to subside and patient stopped to complain by the 10th day, and the last patient agreed to undergo EBP; and headache was relived immediately after 2 h.ConclusionIt could be concluded that re-insertion of epidural catheter at higher level of accidental dural puncture with epidural continuous infusion for 24 h could be considered as an efficient prophylactic modality to safe guard against PDPH with success rate of 75% and minimizes its severity if occurred.     

Continuous epidural pumping of saline contributes to prevent and treat postdural puncture headache

Study ObjectivePostdural puncture headache (PDPH) is the most common symptom of accidental dural puncture, a frequent complication of intraspinal anesthesia. We developed a postoperative intervention technique to prevent and treat PDPH in accidental dural puncture patients, including epidural pumping of saline. This retrospective study aimed to retrospectively evaluate this new technique for PDPH prevention and treatment.DesignRetrospective study.SettingBeijing Obstetrics and Gynecology Hospital affiliated to the Capital Medical University, between January 2006 and December 2012.PatientsEighty-seven cases undergoing intraspinal anesthesia were assessed.InterventionsOf these patients, 68 cases had successful repuncture and were assigned to group A (epidural filling group, n = 68), receiving continuous epidural pumping of 0.9% NS (150 mL) at a rate of 6 mL/h; the remaining cases were assigned to group B (conservative therapy group, n = 19).MeasurementsAge, height, and body weight were collected, and postoperative headache was assessed using a visual analog scale.Main ResultsOf 68 patients in group A, 49 (72.1%) developed PDPH, whereas all in group B developed PDPH (P = .009). In addition, all patients showed PDPH within 3 days after surgery regardless of treatment group. However, a statistically significant difference was obtained for PDPH duration between groups A and B (P < .001). Multivariate logistic regression analysis showed that frequency of epidural puncture and continuous epidural pumping of saline were significant risk factors for PDPH.ConclusionsOur data indicated that application of 6 mL/h saline effectively contributes to PDPH management, and its clinical application should be broadened.     

Minimising the risk of accidental dural puncture with epidural analgesia for labour: a retrospective review of risk factors

BackgroundAccidental dural puncture has a quoted incidence of between 0.19% and 3.6% of obstetric epidurals and is associated with significant morbidity. We set out to determine possible factors associated with an increased risk of accidental dural puncture.MethodsWe performed a retrospective review of 18 385 epidurals, performed over a 15-year period. Factors analysed were: time of day of insertion, loss-of-resistance technique, maternal position, cervical dilatation, grade of anaesthetist and depth to the epidural space.ResultsUsing univariate analyses we found no association between the risk of accidental dural puncture and the following variables: time of day of insertion (P = 0.71), loss-of-resistance technique (P = 0.22), maternal position for insertion (P = 0.83), degree of cervical dilatation (P = 0.41) and grade of anaesthetist performing the epidural (P = 0.34). Conversely, we found that the risk of accidental dural puncture increased with increasing depth to the epidural space. This was confirmed using a logistic regression analysis, from which it was estimated that, for every 1-cm increase in depth, the risk of accidental dural puncture increased by approximately 19% (P = 0.019; 95% CI for OR: 1.029–1.38).ConclusionWe conclude that the risk of accidental dural puncture increases with increasing depth to the epidural space. We suggest further study is required to correlate this risk with increasing body mass index.     

The incidence and management of inability to advance Arrow FlexTip Plus® epidural catheters in obstetric patients

BackgroundDifficulty advancing epidural catheters is troublesome to obstetric anesthesiologists. Flexible epidural catheters have been shown to reduce paresthesiae and intravascular catheter placement in parturients, but the cause of inability to advance these catheters past the epidural needle tip remains undefined. Specifically, its incidence and effective management strategies have not been described.MethodsAll labor epidural catheters were recorded for a 22-week period. Difficulty advancing the epidural catheter was defined as an inability to advance the catheter beyond the needle tip after obtaining loss of resistance. Anesthesiologists completed a survey when difficulty advancing a catheter occurred.ResultsA total of 2148 epidural catheter placements were performed. There were 97 cases of an inability to advance the epidural catheter (4.5%, 95% CI 3.7 to 5.5%). This occurred in 4.2% of combined spinal-epidural and 4.6% of epidural placements (OR 0.92, 95% CI 0.53 to 1.62). On a 0 to 10 scale, the median [IQR] provider confidence in loss of resistance was 9 [8, 10]. A total of 230 corrective maneuvers were performed, using nine distinct approaches. The incidence of accidental dural puncture was 3.1% if an inability to advance occurred (n = 97) compared to 1.2% for other placements (n = 2051, P = 0.12).DiscussionInability to advance Arrow FlexTip Plus® epidural catheters was relatively common (4.5%) and occurred despite confidence in obtaining loss of resistance. Injecting saline may be corrective and appears to have little disadvantage. However, removing the needle and performing a new placement was the most successful corrective maneuver.     

The management of accidental dural puncture during labour epidural analgesia: a survey of UK practice

The management of accidental dural puncture and postdural puncture headache in obstetric practice continues to be of great interest. This survey aims to explore the current management of this complication in the United Kingdom and compares the findings to a similar survey undertaken in 1993. A postal questionnaire was sent to all maternity units (n = 248). The return rate was 71%. Of these, 144 units (85%) now have written guidelines for the management of accidental dural puncture compared to 58% in 1993. In 47 units (28%), the epidural catheter is now routinely placed intrathecally following accidental dural puncture; in 69 units (41%) the catheter is re-sited and in the remaining 53 units (31%) either option is allowed. This is in contrast to the previous survey, which found that catheters were re-sited in 99% of units. Only 31 units (18%) now limit the second stage of labour and 19 (11%) avoid pushing and deliver by ventouse or forceps, whilst 116 units (69%) allow labour to take place without any intervention. Only 44 units (26%) now treat postdural puncture headache with an epidural blood patch as soon as it is diagnosed, whereas in 120 units (71%) the blood patch is performed only after failure of conservative measures. Due to the large increase in the use of the intrathecal catheter following this complication, a follow-up questionnaire was posted 5 months later to those units (n = 99) that reported this practice in the initial survey, with a 94% response rate. The two most commonly cited reasons for intrathecal catheterisation were to avoid further dural puncture (76%) and to allow immediate analgesia for labour (75%).     

Observational study of continuous spinal anesthesia with the catheter-over-needle technique for cesarean delivery

BackgroundFew studies have assessed the efficacy and safety of continuous spinal anesthesia in obstetrics, although placement of a catheter in the intrathecal space theoretically offers advantages in these patients.MethodsNinety-two women scheduled for elective cesarean delivery using continuous spinal anesthesia with the catheter-over-needle technique (22- or 24-gauge Spinocath^®) were included in the study. The doses of local anesthetic used, hemodynamic variables, use of ephedrine and other drugs, and incidence of complications such as technical failure and postdural puncture headache (PDPH) were recorded.ResultsThe mean (±SD) dose of hyperbaric bupivacaine used was 8.2 ± 1.8 mg. The incidence of hypotension was 30% and the mean total dose of ephedrine was 4 ± 7 mg. The continuous spinal anesthetic technique failed in 18 women (20%). The overall incidence of post-dural-puncture headache was 29%; 18% of patients with post-dural-puncture headache required a blood patch.ConclusionsCompared to previous reports, the incidence of block failure and PDPH in this study was unacceptably high and therefore the risks of the technique appear to outweigh the advantages of continuous spinal anesthesia in obstetric practice.     

Observational study of changes in epidural pressure and elastance during epidural blood patch in obstetric patients

BackgroundDuring an epidural blood patch, we inject blood until the patient describes mild back pressure, often leading to injection of more than 20 mL of blood. We undertook this study to measure the epidural pressures generated during an epidural blood patch and to identify the impact of volume on epidural elastance in obstetric patients.MethodsThis study was performed in postpartum patients who presented for an epidural blood patch with symptoms consistent with a postdural puncture headache. After identification of the epidural space using loss of resistance to air or saline, we measured static epidural pressure after each 5-mL injection of blood. Models were then fitted to the data and the epidural elastance and compliance calculated.ResultsEighteen blood patches were performed on 17 patients. The mean final volume injected was 18.9 ± 7.8 mL [range 6–38 mL]. The mean final pressure generated was 13.1 ± 13.4 mmHg [range 2–56 mmHg]. A curvilinear relationship existed between volume injected and pressure, which was described by two models: (1) pressure = 0.0254 × (mL injected)² + 0.0297  mL, or (2) pressure = 0.0679 × mL^1.742. The value for r² was approximately 0.57 for both models. We found no correlation between the final pressure generated and the success of the epidural blood patch.ConclusionsWe found a curvilinear relationship between the volume of blood injected during an epidural blood patch and the pressure generated in the epidural space. However, there was a large variation in both the volume of blood and the epidural pressure generated. The clinical importance of this finding is not known. A larger study would be required to demonstrate whether pressure is a predictor of success.     

Pregnant women’s views on informed consent for research in labour

BackgroundStudies of the optimal treatment of accidental dural puncture occurring during epidural insertion in labour are difficult for practical reasons and because of the ethical issues around seeking consent. In a recent study of accidental dural puncture, participants were assigned to one of two treatment groups and only informed about the study and consent sought, after treatment. We sought the views of parturients on the timing of consent for such a study.MethodsAfter ethical approval and written consent, 100 nulliparous women in the third trimester of pregnancy completed a structured, facilitated questionnaire, rating the acceptability of the consent process occurring: (i) in antenatal clinic; (ii) after the epidural was requested in labour; (iii) after the accidental dural puncture had occurred but before treatment; (iv) after the allocated treatment; or (v) without consent (waived consent). Results were analysed with the Friedman and Wilcoxon signed-rank tests.ResultsAntenatal consent was considered the most acceptable option, whilst consent on request for epidural analgesia and after accidental dural puncture were least acceptable. Consent after treatment and waived consent were rated in-between these extremes. There was a statistically significant difference between these three groups (P < 0.0001). There was a wide range of opinions on each option presented.ConclusionsAntenatal consent was the preferred option but if this is not possible and the need for the research is strong, consent for the use of women’s data after intervention, or waived consent, is acceptable to many women. It is important to seek the views of the participants themselves before planning research with difficult ethical aspects.     

A comparison of epidural and cerebrospinal fluid glucose in parturients at term: an observational study

BackgroundDetecting inadvertent dural puncture during labour epidural insertion can be difficult when using a loss of resistance to saline technique. Testing fluid for glucose that leaks from a Tuohy needle may confirm the presence of cerebrospinal fluid and infer inadvertent dural puncture. This study compared the glucose content of intrathecal fluid obtained during spinal anaesthesia for elective caesarean delivery with that of fluid from a Tuohy needle or epidural catheter when establishing epidural analgesia for labour.MethodsWomen aged ?18 years undergoing elective caesarean delivery and labouring parturients who requested epidural analgesia were recruited prospectively in a tertiary referral centre over a three-month period. Fluid was collected into a sterile container either during spinal anaesthesia or from a labour epidural needle. Glucose content was evaluated using a bedside blood glucometer and laboratory colorimetric analyzer.ResultsOf the 118 women approached, 115 participated. All 40 women having spinal anaesthesia and 2/75 (2.7%) women having epidural analgesia, in whom inadvertent dural puncture was subsequently confirmed, had fluid samples testing positive for glucose. Median [range] laboratory glucose readings were 2.9 [1.3–5.1] mmol/L for cerebrospinal fluid and <0.3 mmol/L in fluid that leaked from a Tuohy needle (P = 0.0001).ConclusionWhen using a loss of resistance to saline technique for epidural catheter placement, bedside glucometer testing of fluid leaking from the epidural needle may be of value in the early detection of inadvertent dural puncture.     

Intrathecal catheterisation after observed accidental dural puncture in labouring women: update of a meta-analysis and a trial-sequential analysis

BackgroundOur meta-analysis from 2013 showed that inserting a catheter intrathecally after an observed accidental dural puncture can reduce the need for epidural blood patch in labouring women requesting epidural analgesia. We updated our conventional meta-analysis and added a trial-sequential analysis (TSA).MethodsA systematic literature search was conducted to identify studies that compared inserting the catheter intrathecally with an epidural catheter re-site or with no intervention. The extracted data were pooled and the risk ratio (RR) and 95% confidence interval (95%CI) for the incidence of post-dural puncture headache (PDPH) was calculated, using the random effects model. A contour-enhanced funnel plot was constructed. A TSA was performed and the cumulative Z score, monitoring and futility boundaries were constructed.ResultsOur search identified 13 studies, reporting on 1653 patients, with a low risk of bias. The RR for the incidence of PDPH was 0.82 (95%CI 0.71 to 0.95) and the RR for the need for epidural blood patch was 0.62 (95%CI 0.49 to 0.79); heterogeneity of both analyses was high. The TSA showed that the monitoring or futility boundaries were not crossed, indicating insufficient data to exclude a type I error of statistical analysis. Contour-enhanced funnel plots were symmetric, suggesting no publication bias.ConclusionsConventional meta-analyses showed for the first time that intrathecal catheterisation can reduce the incidence of PDPH. However, TSA did not corroborate this finding. Despite increasing use in clinical practice there is no firm evidence on which to base a definite conclusion.     

Complications of 761 short-term intrathecal macrocatheters in obstetric patients: a retrospective review of cases over a 12-year period

BackgroundA continuous spinal catheter is a reliable alternative to standard neuraxial techniques in obstetric anesthesia. Despite the potential advantages of intrathecal catheters, they remain underutilized due to fear of infection, nerve damage or post-dural puncture headache. In our tertiary care center, intrathecal catheters are either placed intentionally in high-risk obstetric patients or following inadvertent dural puncture using a 19-gauge macrocatheter passed through a 17-gauge epidural needle.MethodsA retrospective review of 761 intrathecal catheters placed from 2001 to 2012 was conducted. An institutional obstetric anesthesia database was used to identify patients with intrathecal catheters. Medical records were reviewed for procedural details and complications.ResultsThere were no serious complications, including meningitis, epidural or spinal abscess, hematoma, arachnoiditis, or cauda equina syndrome, associated with intrathecal catheters. The failure rates were 2.8% (3/108) for intentional placements and 6.1% (40/653) for placements following accidental dural puncture. The incidence of post-dural puncture headache was 41% (312/761) and the epidural blood patch rate was 31% (97/312).ConclusionsThis review demonstrates that intrathecal catheters are dependable and an option for labor analgesia and surgical anesthesia for cesarean delivery. Serious long-lasting complications are rare.