PDPH is a common complication of neuraxial blockade in parturients: a meta-analysis of obstetrical studies

Management practices for postdural puncture headache in obstetrics: a prospective, international, cohort study

BACKGROUND

Accidental dural puncture is an uncommon complication of epidural analgesia and can cause postdural puncture headache (PDPH). We aimed to describe management practices and outcomes after PDPH treated by epidural blood patch (EBP) or no EBP.

METHODS

Following ethics committee approval, patients who developed PDPH after accidental dural puncture were recruited from participating countries and divided into two groups, those receiving EBP or no EBP. Data registered included patient and procedure characteristics, headache symptoms and intensity, management practices, and complications. Follow-up was at 3 months.

RESULTS

A total of 1001 patients from 24 countries were included, of which 647 (64.6%) received an EBP and 354 (35.4%) did not receive an EBP (no-EBP). Higher initial headache intensity was associated with greater use of EBP, odds ratio 1.29 (95% confidence interval 1.19-1.41) per pain intensity unit increase. Headache intensity declined sharply at 4 h after EBP and 127 (19.3%) patients received a second EBP. On average, no or mild headache (numeric rating score≤3) was observed 7 days after diagnosis. Intracranial bleeding was diagnosed in three patients (0.46%), and backache, headache, and analgesic use were more common at 3 months in the EBP group.

CONCLUSIONS

Management practices vary between countries, but EBP was more often used in patients with greater initial headache intensity. EBP reduced headache intensity quickly, but about 20% of patients needed a second EBP. After 7 days, most patients had no or mild headache. Backache, headache, and analgesic use were more common at 3 months in patients receiving an EBP.

Conventional landmark palpation vs. preprocedural ultrasound for neuraxial analgesia and anaesthesia in obstetrics - a systematic review and meta-analysis with trial sequential analyses

The aim of this systematic review and meta-analysis was to examine the efficacy, time taken and the safety of neuraxial blockade performed for obstetric patients with the assistance of preprocedural ultrasound, in comparison with the landmark palpation method. The bibliographic databases Central, CINAHL, EMBASE, Global Health, MEDLINE, Scopus and Web of Science were searched from inception to 13 February 2020 for randomised controlled trials that included pregnant women having neuraxial procedures with preprocedural ultrasound as the intervention and conventional landmark palpation as the comparator. For continuous and dichotomous outcomes, respectively, we calculated the mean difference using the inverse-variance method and the risk ratio with the Mantel-Haenszel method. In all, 22 trials with 2462 patients were included. Confirmed by trial sequential analysis, preprocedural ultrasound increased the first-pass success rate by a risk ratio (95%CI) of 1.46 (1.16-1.82), p = 0.001 in 13 trials with 1253 patients. No evidence of a difference was found in the total time taken between preprocedural ultrasound and landmark palpation, with a mean difference (95%CI) of 50.1 (-13.7 to 113.94) s, p = 0.12 in eight trials with 709 patients. The quality of evidence was graded as low and very low, respectively, for these co-primary outcomes. Sub-group analysis underlined the increased benefit of preprocedural ultrasound for those in whom the neuraxial procedure was predicted to be difficult. Complications, including postpartum back pain and headache, were decreased with preprocedural ultrasound. The adoption of preprocedural ultrasound for neuraxial procedures in obstetrics is recommended and, in the opinion of the authors, should be considered as a standard of care, in view of its potential to increase efficacy and reduce complications without significant prolongation of the total time required.

[Postdural puncture headache after neuraxial anesthesia: incidence and risk factors]

Hintergrund/Ziel der Arbeit

Der postpunktionelle Kopfschmerz (PKS) ist eine Komplikation nach rückenmarknahen Verfahren (RA) mit erheblichem Krankheitswert. Ziel der Untersuchung war es, die Inzidenz des PKS in 2 großen operativen Kollektiven zu untersuchen, mögliche Risikofaktoren zu identifizieren und den Einfluss auf die Krankenhausverweildauer zu untersuchen.

Material und Methoden

In einer retrospektiven Analyse des Zeitraums 2010–2012 wurden 341 unfallchirurgische (UCH) und 2113 geburtsmedizinische (GEB) Patient*innen nach Spinalanästhesie (SPA) analysiert. In der statistischen Auswertung (SPSS-23) kamen univariate Analysen mittels Mann-Whitney-U-, Chi²- und Student’s t‑Test sowie logistische Regressionsanalysen zur Anwendung.

Ergebnisse

Die Inzidenz des PKS betrug in der UCH-Gruppe 5,9 % und in der GEB-Gruppe 1,8 %. Patient*innen mit PKS in der UCH wiesen ein jüngeres Patientenalter (38 vs. 47 Jahre, p = 0,011), einen geringeren BMI (23,5 vs. 25,2, p = 0,037) sowie ein niedrigeres Köpergewicht (70,5 kg vs. 77 kg, p = 0,006) als Patient*innen ohne PKS auf. Dabei konnten das Alter mit einer „odds ratio“ (OR 97,5 % Konfidenzintervall [KI]) von 0,963 (97,5% KI 0,932–0,991, p = 0,015) und das Köpergewicht mit einer OR von 0,956 (97,5 % KI 0,920–0,989, p = 0,014) als unabhängige Risikofaktoren für die Entstehung eines PKS identifiziert werden. In der GEB wies die SPA eine höhere Inzidenz des PKS auf als die kombinierte Spinalepiduralanästhesie (CSE) (8,6 % vs. 1,2 %, p < 0,001). Dabei erwies sich das Verfahren mit einer OR von 0,049 (97,5 % KI 0,023–0,106, p < 0,001) als unabhängiger Risikofaktor für die Entstehung eines PKS. In beiden Gruppen war der PKS mit einem verlängerten Krankenhausaufenthalt assoziiert (UCH-Gruppe 4 vs. 2 Tage, p = 0,001; GEB-Gruppe 6 vs. 4 Tage, p < 0.0005).

Diskussion

Die Inzidenz des PKS nach SPA/CSE war in unserer Untersuchung in den beschriebenen Patientengruppen unterschiedlich, mit einem deutlich höheren Anteil in der UCH-Gruppe. Alter, Konstitution und Verfahren waren hinweisgebende Risikofaktoren eines PKS. In Anbetracht der funktionellen Einschränkungen (Mobilisation, Versorgung des Neugeborenen) und des verlängerten Krankenhausaufenthalts, sollten zukünftige Studien eine frühe Behandlung des PKS untersuchen.

Prophylactic Intrathecal Morphine and Prevention of Post-Dural Puncture Headache: A Randomized Double-blind Trial

BACKGROUND

Prophylactic epidural morphine administration after unintentional dural puncture with a large-bore needle has been shown to decrease the incidence of post-dural puncture headache. The authors hypothesized that prophylactic administration of intrathecal morphine would decrease the incidence of post-dural puncture headache and/or need for epidural blood patch after unintentional dural puncture.

METHODS

Parturients with an intrathecal catheter in situ after unintentional dural puncture with a 17-g Tuohy needle during intended epidural catheter placement for labor analgesia were enrolled in this randomized, double-blind trial. After delivery, subjects were randomized to receive intrathecal morphine 150 µg or normal saline. The primary outcome was the incidence of post-dural puncture headache. Secondary outcomes included onset, duration, and severity of post-dural puncture headache, the presence of cranial nerve symptoms and the type of treatment the patient received.

RESULTS

Sixty-one women were included in the study. The incidence of post-dural puncture headache was 21 of 27 (78%) in the intrathecal morphine group and 27 of 34 (79%) in the intrathecal saline group (difference, -1%; 95% CI, -25% to 24%). There were no differences between groups in the onset, duration, or severity of headache, or presence of cranial nerve symptoms. Epidural blood patch was administered to 10 of 27 (37%) of subjects in the intrathecal morphine and 11 of 21 (52%) of the intrathecal saline group (difference 15%; 95% CI, -18% to 48%).

CONCLUSIONS

The present findings suggest that a single prophylactic intrathecal morphine dose of 150 µg administered shortly after delivery does not decrease the incidence or severity of post-dural puncture headache after unintentional dural puncture. This study does not support the clinical usefulness of prophylactic intrathecal morphine after an unintentional dural puncture.

Pneumocephalus and Chemical Meningitis after Inadvertent Dural Puncture during Lumbar Epidural Injection

Inadvertent dural puncture (IDP) is one of the complications of lumbar epidural steroid injections (ESIs). We report a case in which pneumocephalus and chemical meningitis developed at the same time after an IDP during a lumbar interlaminar ESI. A 60-year-old woman presented to the emergency room with thunderclap headache and febrile sensation 3 hours after receiving a lumbar interlaminar ESI. Brain computed tomography (CT) scan showed multiple small foci of air within the subarachnoid space and ventricle. After the admission, the patient was afebrile and reported mild improvement of headache with analgesics. However, 2 days after the admission, headache worsened and fever recurred. Follow-up brain CT scan revealed resolution of the pneumocephalus. A diagnostic lumbar puncture for cerebrospinal fluid (CSF) examination revealed the findings suggestive of aseptic (chemical) meningitis rather than bacterial meningitis. With symptomatic treatment, headache improved and there was no fever after 48 hours. No bacteria, Mycobacterium, or fungi grew in the CSF for 7 days. This case shows an IDP during a lumbar ESI can cause pneumocephalus and chemical meningitis at the same time and efforts should be made to reduce the risk of IDP during lumbar ESIs.

Does the Technique for Assessing Loss of Resistance Alter the Magnitude of Epidural Needle Tip Overshoot?

INTRODUCTION

Postdural puncture headache due to accidental dural puncture is a consequence of excessive needle tip overshoot distance after entering the epidural space via a loss of resistance (LOR) technique. We are not aware of any quantitative comparison of the magnitude of needle tip overshoot (distance traveled by the needle tip beyond the point where LOR can be discerned) for the various LOR assessment techniques that are taught. Such a comparison may provide insight into contributing factors of accidental dural puncture and associated postdural puncture headache.

METHODS

A custom-built simulator was used to evaluate the following 3 LOR assessment techniques: incremental needle advancement, intermittent LOR assessment (II); continuous needle advancement, high-frequency intermittent LOR assessment (CI); and continuous needle advancement, continuous LOR assessment (CC).

RESULTS

There were significant mean differences in maximum overshoot past a virtual LOR plane due to technique (F(2,124) = 79.31, P < 0.001) (Fig. 2). Specifically, maximum overshoot was greater with technique II [mean = 3.8 mm, 95% confidence interval (CI) = 3.4-4.3] versus either CC (mean = 1.9 mm, 95% CI = 1.5-1.8, P < 0.001) or CI (mean = 1.4 mm, 95% CI = 0.9-2.3, P < 0.001). Differences in maximum overshoot between CC and CI were not statistically different (P = 0.996). Maximum overshoot was greater at 4 cm (mean = 3.0 mm, 95% CI = 2.6-3.4) compared with 5 cm (mean = 2.3 mm, 95% CI = 2.0-2.5, P = 0.044), 6 cm (mean = 2.0 mm, 95% CI = 1.9-2.2, P = 0.054), 7 cm (mean = 1.9 mm, 95% CI = 1.7-2.1, P = 0.002), and 8 cm (mean = 1.8 mm, 95% CI = 1.6-2.1, P = 0.001). In addition, maximum overshoot at 5 cm was greater than that at 7 cm (P = 0.020) and 8 cm (P = 0.037). The other LOR depths were not statistically significantly different from each other. Depth did not have a significant interaction with technique (P = 0.517). Technique preference had neither a significant relationship to maximum overshoot (P = 0.588) nor a significant interaction with LOR assessment technique (P = 0.689).

DISCUSSION

Technique II LOR assessment produced the greatest needle overshoot past the simulated LOR plane after obtaining LOR. This was consistent across all LOR depths. In this bench study, the II technique resulted in the deepest needle tip maximum overshoot. We are in the process of designing a clinical study to collect similar data in patients.

Use of a Triple Prophylactic Strategy to Prevent Post-dural Puncture Headache: An Observational Study

Objective

Post-dural puncture headache (PDPH) after an accidental dural puncture is a very common complication of epidural analgesia/anesthesia. We observed the ability of a triple prophylactic method (epidural saline, morphine, and intravenous (IV) cosyntropin) to prevent PDPH and the need for a blood patch. 

Methods

We retrospectively evaluated the effect of the combination of epidural saline, IV cosyntropin, and epidural morphine in parturients who had an accidental dural puncture with regard to the PDPH rate and the need for an epidural blood patch. We report a case series of patients with accidental dural puncture who underwent triple prophylaxis and other methods.

Results

Thirty-one patients were included in the study. Fourteen cases received triple prophylaxis (45%). Three patients in this group developed PDPH (21%), with two of them requiring a blood patch (14%). Nine patients underwent preventive measures other than triple prophylaxis with a PDPH rate of 55% and one needing a blood patch (11%). Conservative management was used in eight patients with PDPH and blood patch rates of 100% and 62%, respectively.

Conclusion

The triple prophylactic regimen of epidural saline, IV cosyntropin, and epidural morphine used after accidental dural puncture exhibits great potential to reduce the incidence of PDPH and the need for blood patch in obstetric patients.

Prospective randomized comparison of cerebrospinal fluid aspiration and conventional popping methods using 27-gauge spinal needles in patients undergoing spinal anaesthesia

Background

Performing spinal anaesthesia using the conventional popping method with a 27-gauge (27G) spinal needle is technically difficult. In this study, we compared the aspiration and conventional popping method for spinal anaesthesia using 27G Quincke-type needles.

Methods

This prospective, randomized study enrolled 90 patients, aged 19 to 65 years, with American Society of Anesthesiologists physical status I-III, who were undergoing spinal anaesthesia. Patients were randomly assigned to one of two groups using a computer-generated random number table: patients receiving spinal anaesthesia using the aspiration method, in which the needle is advanced with continuous aspiration, or the conventional popping method. The primary outcome measure was the success rate of the first attempt to perform dural puncture. Number of attempts and passages, withdrawal cases, successful attempt time, total procedure time, and actual depth of dural puncture were recorded.

Results

Eighty-eight patients were included in the study. In the aspiration group, the success rate of first attempt for dural puncture was 93.3%, compared with 72.1% in the popping group (P = 0.019). Success involving needle withdrawal was recorded in 4 (8.9%) patients in the aspiration group and 13 (30.2%) in the popping group (P = 0.024). In the popping group, the number of attempts was significantly higher (P = 0.044), and total procedure time was significantly longer (P = 0.023). Actual depths of dural puncture were deeper in the popping group than in the aspiration group (P = 0.019).

Conclusions

The aspiration method using a 27G Quincke-type needle offers clinical benefits for dural puncture compared with the conventional popping method for spinal anaesthesia.

Trial registration

Clinical research information service number: KCT0002815, registered 21/Apr/2018. Retrospectively registered.

CVT in the Peripartum Period: A Diagnostic Dilemma

Women in the peripartum period can develop headache with a variety of etiologies that require a multidisciplinary approach if unresponsive to treatment (Stella et al. 2007). Neuroimaging needs to be undertaken even occasionally in the absence of focal neurologic signs to rule out life-threatening causes of headache. We present the case of a 23-year-old woman who presented postpartum with severe frontal headache without other neurologic symptoms. Treatment was initiated for tension type, then subsequently postdural puncture headache (PDPH), and finally preeclampsia. When CT venogram was obtained ten days later, the diagnosis of cerebral venous thrombosis (CVT) was made. She was started on anticoagulation and achieved complete recovery.

Evaluation of the effectiveness and tolerance of tetracosactide in the treatment of post-dural puncture headaches (ESYBRECHE): a study protocol for a randomised controlled trial

Background

Post-dural puncture headache (PDPH) is one of the most common complications of neuraxial anaesthesia. It limits patients’ general activity and increases the length of hospital stays and the use of care. It is particularly disabling during the postpartum period, when mothers have to take care of their child. Epidural blood patch is the standard treatment for PDPH. However, it is an invasive procedure that may result in rare but serious complications. Recent evidence has suggested that adrenocorticotropic hormone (ACTH) is effective in the management of PDPH. The aim of this study is to assess the efficacy and safety of tetracosactide (Synacthen®), a synthetic analogue of ACTH, for PDPH treatment in patients who receive neuraxial anaesthesia during labour.

Methods

This randomised, double-blind, placebo-controlled, parallel-arm trial, is performed in two French university hospitals. Eligible patients are those suffering from postpartum PDPH, who are randomised to receive either 1 mg of tetracosactide intravenously over 20 min or to 0.9% saline (placebo). The primary endpoint is the rate of epidural blood patch within a 15-day follow-up period. Headache duration, pain intensity, reduction of general activity, increase in length of hospital stay, adverse events, analgesic use (type and duration) and number of blood patches per patient in each group are recorded.

Discussion

We expect a decrease in the use of epidural blood patch in those receiving tetracosactide, thus indicating a decrease in PDPH symptoms in these patients. This will define the therapeutic success of tetracosactide and the possibility to use this treatment as a non-invasive alternative to blood patch for PDPH treatment.

Trial registration

Primary Registry

ClinicalTrials.gov Protocol Registration and Results System

Date of Registration 24 June 2016

Unique Protocol ID 69HCL15_0429

Secondary IDs

EudraCT Number 2015–003357-17

ClinicalTrials.gov ID NCT02813655

ANSM 160214A-31

Protocol version

V4 28/09/2018

Post Dural Puncture Headache, Managed with Epidural Blood Patch, Is Associated with Subsequent Chronic Low Back Pain in Patients: a Pilot Study

PURPOSE OF REVIEW

Post dural puncture headache (PDPH) is a relatively common complication which may occur in the setting of inadvertent dural puncture (DP) during labor epidural analgesia and during intentional DP during spinal anesthetic placement or diagnostic lumbar puncture. Few publications have established the long-term safety of an epidural blood patch (EBP) for the treatment of a PDPH.

RECENT FINDINGS

The aim of this pilot study was to examine the association of chronic low back pain (LBP) in patients who experienced a PDPH following labor analgesia and were treated with an EBP. A total of 146 patients were contacted and completed a survey questionnaire via telephone. The EBP group was found to be more likely to have chronic LBP (percentage difference 20% [95% CI 6-33%], RR 2.6 [95% CI 1.3-5.2]) and also LBP < 6 (percentage difference 24% [95% CI 9- 37%], RR 2.3 [95% CI 1.3-4.1]). There were no significant differences in the severity and descriptive qualities of pain between the EBP and non-EBP groups. Our findings suggest that PDPH treated with an EBP is associated with an increased prevalence of subsequent low back pain in parturients. The findings of this pilot study should spur further prospective research into identifying potential associations between DP, EBP, and chronic low back pain.

Effect of Low-Dose Intravenous Ketamine on Prevention of Headache After Spinal Anesthesia in Patients Undergoing Elective Cesarean Section: A Double-Blind Clinical Trial Study

Background

Spinal anesthesia is the most commonly used method for elective cesarean section, which is a popular technique due to its simplicity, reliability, and speed to achieve adequate anesthesia. Headache following dura perforation is the most important delayed complication following spinal and epidural anesthesia.

Objectives

To evaluate the impact of low-dose intravenous ketamine in patients undergoing cesarean section under spinal anesthesia on the prevention of dura perforation headache (PDPH).

Methods

This clinical trial study was performed on 64 pregnant women undergoing cesarean section at Vali-e-Asr Hospital. The patients were divided into two groups. In the case group, 0.15 mg/kg body weight ketamine was injected intravenously and in the control group, normal saline was used as the placebo. The incidence of headache and its severity at one, 4, 12, and 24 hours postoperatively, nausea and its severity were also measured and compared. Independent t-test, Mann-Whitney U and chi-square tests were used. A P value < 0.05 was considered statistically significant.

Results

The data revealed that low dose intravenous ketamine significantly decreased patients’ headaches (P = 0.001), the sensation of pruritus (P = 0.009), and the need for analgesic (P = 0.001). Furthermore, the sensation of postoperative nausea was less in the case group. The patients in the case and control groups had no significant difference in terms of hypertension or bradycardia (P = 0.717 and 0.939, respectively).

Conclusions

The injection of ketamine as a premedication in the cesarean section can reduce the severity of postoperative headache in mothers. Therefore, it is recommended to use ketamine as an anti-headache drug in pregnant women.

Accidental dural puncture and post-dural puncture headache: a retrospective review in an Irish maternity hospital

BACKGROUND

Accidental dural puncture (ADP) during epidural catheter insertion and the possible consequent post-dural puncture headache (PDPH) remain challenging complications in obstetric anaesthesia. ADP/PDPH can represent a considerable degree of morbidity for the parturient and require immediate diagnosis and appropriate management to ensure recovery and avoid complications.

AIM

This retrospective audit was carried out to identify the accidental dural puncture and post-dural puncture headache rates at the Coombe Women and Infant University Hospital in Dublin.

METHODS

Cases of ADP and PDPH were identified retrospectively from a register used to record these cases. Demographic and obstetric data was retrieved using the patients' medical records. Analysis was carried using MS Excel.

RESULTS

In 1 year (June 1, 2018 to June 1, 2019), there were 25 cases of ADP during epidural catheter insertion and this is 0.78% of epidurals done in this period. Seventeen of these (68%) subsequently developed PDPH. In total, there are 32 cases of PDPH: 27 after epidural analgesia using an 18G Touhy needle and 5 after a spinal anaesthetic using a 25G Whitacre needle. All PDPH cases received first-line conservative treatment and 9 (28.1%) required an epidural blood patch (EBP). No-one required a second EBP.

DISCUSSION

The incidence of ADP at our hospital (0.78%) is within the range quoted in the literature (0.1-1.5%) and below the UK standard of 1%. The incidence of PDPH after recognized ADP (68%) is also consistent with other published reports.

Is There An Effect On The Development Of Postdural Puncture Headache Of Dural Punction Made With The Spinal Needle In Three Different Orientations During Spinal Anaesthesia Applied To Pregnant Patients?

BACKGROUND AND OBJECTIVES

Postdural punction headache (PDPH) is a well-known and common complication of spinal anesthesia. The relationship between spinal needle size, configuration and perforation characteristics of the spinal needle and non-essential leak continues to be controversial.

METHODS

This prospective-randomized study included 300 patients aged 18-45 years who underwent cesarean section under spinal anesthesia. Spinal anesthesia was performed using a 26G Quincke spinal needle in the L3-4, or L4-5 range in the sitting position. Spinal anesthesia was performed with spinal needle sharp tip opening in the Group 1 patients, right or left laterally in Group 2 and caudal in Group 3, transducing the dural fibers transversely to the subarachnoid area, and directing the free opening of the needle to the spine. The patients were visited in the clinic where they were hospitalized at the 24th and 48th hours postoperatively, and phoned on the 3rd and 5th days after discharge, being questioned for PDPH.

RESULTS

It was observed that 64% of patients with PDPH developed within the first 24 hrs, 24% between 24 and 48 hrs and 48-72 hrs in 12%. The incidence of PDPH was 14% in Group 1, 8% in Group 2 and 3% in Group 3. This difference between the groups was statistically significant (p: 0.019). The incidence of PDPH was lower in Group 3 than in Group 1 and Group 2.

CONCLUSION

We suggest that when spinal anesthesia is applied in the obstetric patient group if needle opening faces caudal this method will reduce the frequency of PDPH.

Inadvertent neuraxial block placement at or above the L1-L2 interspace in the super-obese parturient: a retrospective study

BACKGROUND

Increasing body mass index (BMI) increases the difficulty of neuraxial procedures. We hypothesized that it may put patients at risk for inappropriately high dural puncture. The accuracy of anesthesiologists' estimates of the interspinous level in super-obese parturients has not been studied. We evaluated the frequency of inadvertently high epidural and/or intrathecal catheter placement (at or above the L1/L2 interspace) in parturients of BMI ≥50 kg/m².

METHODS

Inclusion criteria for this retrospective study were women with a BMI ≥50 kg/m² who delivered by cesarean with an epidural or intrathecal catheter. The primary outcome was the percentage of catheters placed at or above L1/L2, determined by reviewing the retained foreign object radiograph. Secondary outcomes were agreement between the estimated and actual catheter location and subgroup analysis of catheters placed under ultrasound guidance.

RESULTS

After excluding 15 cases for which the catheter location could not be determined and 10 cases for which the estimated level of insertion was not recorded, 125 cases were included. Inadvertent high placement occurred in 26/125 (21%, 95% confidence interval (CI) 15% to 29%) patients. There was poor agreement between the estimated and actual catheter location (27% accurate, unweighted κ-statistic 0.02). Eleven of 39 catheters placed with ultrasound (28%, 95% CI 17% to 44%) were at or above L1/L2 compared with 15/86 catheters placed without ultrasound (17%, 95% CI 11% to 27%, P=0.17). There were no neurological complications.

CONCLUSIONS

A high rate of inadvertently high epidural or intrathecal catheter placement occurs in super-obese parturients. Ultrasound did not prevent this.

Combined spinal-epidural versus spinal anaesthesia for caesarean section

BACKGROUND

Single-shot spinal anaesthesia (SSS) and combined spinal-epidural (CSE) anaesthesia are both commonly used for caesarean section anaesthesia. Spinals offer technical simplicity and rapid onset of nerve blockade which can be associated with hypotension. CSE anaesthesia allows for more gradual onset and also prolongation of the anaesthesia through use of a catheter.

OBJECTIVES

To compare the effectiveness and adverse effects of CSE anaesthesia to single-shot spinal anaesthesia for caesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies (search date: 8 August 2019).

SELECTION CRITERIA

We considered all published randomised controlled trials (RCTs) involving a comparison of CSE anaesthesia with single-shot spinal anaesthesia for caesarean section. We further subgrouped spinal anaesthesia as either high-dose (10 or more mg bupivacaine), or low-dose (less than 10 mg bupivacaine).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risks of bias, extracted data and checked them for accuracy. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified 18 trials including 1272 women, but almost all comparisons for individual outcomes involved relatively small numbers of women. Two trials did not report on this review's outcomes and therefore contribute no data towards this review. Trials were conducted in national or university hospitals in Australia (1), Croatia (1), India (1), Italy (1), Singapore (3), South Korea (4), Spain (1), Sweden (1), Turkey (2), UK (1), USA (2). The trials were at a moderate risk of bias overall.CSE versus high-dose spinal anaesthesiaThere may be little or no difference between the CSE and high-dose spinal groups for the number of women requiring a repeat regional block or general anaesthetic as a result of failure to establish adequate initial blockade (risk ratio (RR) 0.32, 95% confidence interval (CI) 0.05 to 1.97; 7 studies, 341 women; low-quality evidence). We are uncertain whether having CSE or spinal makes any difference in the number of women requiring supplemental intra-operative analgesia at any time after CSE or spinal anaesthetic insertion (average RR 1.25, 95% CI 0.19 to 8.43; 7 studies, 390 women; very low-quality evidence), or the number of women requiring intra-operative conversion to general anaesthesia (RR 1.00, 95% CI 0.07 to 14.95; 7 studies, 388 women; very low-quality evidence). We are also uncertain about the results for the number of women who were satisfied with anaesthesia, regardless of whether they received CSE or high-dose spinal (RR 0.93 95% CI 0.73 to 1.19; 2 studies, 72 women; very low-quality evidence). More women in the CSE group (13/21) experienced intra-operative nausea or vomiting requiring treatment than in the high-dose spinal group (6/21). There were 11 cases of post-dural puncture headache (5/56 with CSE versus 6/57 with SSS; 3 trials, 113 women) with no clear difference between groups. There was also no clear difference in intra-operative hypotension requiring treatment (46/86 with CSE versus 41/76 with SSS; 4 trials, 162 women). There were no babies with Apgar score less than seven at five minutes (4 trials, 182 babies).CSE versus low-dose spinal anaesthesiaThere may be little or no difference between the CSE and low-dose spinal groups for the number of women requiring a repeat regional block or general anaesthetic as a result of failure to establish adequate initial blockade (RR 4.81, 95% CI 0.24 to 97.90; 3 studies, 224 women; low-quality evidence). Similarly, there is probably little difference in the number of women requiring supplemental intra-operative analgesia at any time after CSE or low-dose spinal anaesthetic insertion (RR 1.75, 95% CI 0.78 to 3.92; 4 studies, 298 women; moderate-quality evidence). We are uncertain about the effect of CSE or low-dose spinal on the need for intra-operative conversion to general anaesthesia, because this was not required by any of the 222 women in the three trials (low-quality evidence). None of the studies examined whether women were satisfied with their anaesthesia.The mean time to effective anaesthesia was faster in women who received low-dose spinal compared to CSE, although it is unlikely that the magnitude of this difference is clinically meaningful (standardised mean difference (SMD) 0.85 minutes, 95% CI 0.52 to 1.18 minutes; 2 studies, 160 women).CSE appeared to reduce the incidence of intra-operative hypotension requiring treatment compared with low-dose spinal (average RR 0.59, 95% CI 0.38 to 0.93; 4 studies, 336 women). Similar numbers of women between the CSE and low-dose spinal groups experienced intra-operative nausea or vomiting requiring treatment (3/50 with CSE versus 6/50 with SSS; 1 study, 100 women), and there were no cases of post-dural puncture headache (1 study, 138 women). No infants in either group had an Apgar score of less than seven at five minutes (1 study; 60 babies).

AUTHORS' CONCLUSIONS

In this review, the number of studies and participants for most of our analyses were small and some of the included trials had design limitations. There was some suggestion that, compared to spinal anaesthesia, CSE could be associated with a reduction in the number of women with intra-operative hypotension, but an increase in intra-operative nausea and vomiting requiring treatment. One small study found that low-dose spinal resulted in a faster time to effective anaesthesia compared to CSE. However, these results are based on limited data and the difference is unlikely to be clinically meaningful. Consequently, there is currently insufficient evidence in support of one technique over the other and more evidence is needed in order to further evaluate the relative effectiveness and safety of CSE and spinal anaesthesia for caesarean section.More high-quality, sufficiently-powered studies in this area are needed. Such studies could consider using the outcomes listed in this review and should also consider reporting economic aspects of the different methods under investigation.

Predictors of difficult epidural placement in pregnant women: A trainees' perspective

BACKGROUND AND AIMS

Epidural analgesia is believed to be the most difficult technique to learn for a trainee. The reason for this is not only inexperience of the provider and the complexity of the technique but also patient factors like obesity, spinal deformity and others which makes the epidural placement difficult. The aim of this study was to evaluate some of the common risk factors for difficult epidural placement as perceived by the anesthesia providers during training, with varying level of experience.

MATERIAL AND METHODS

This prospective observational study includes patients who received epidural placement for labor analgesia. Data recorded on these patients included age, height, weight, body mass index (BMI), ease of palpation of the spinous process, level of epidural placement, number of attempts, time taken for epidural placement and experience of the provider. The association between the variables were assessed using logistic regression for first attempt success and Cox proportional hazard ratio for time to epidural placement.

RESULTS

A total of 373 patients received epidural placement for labor analgesia. The mean BMI at the time of placement was 34. The first attempt success rate for the placement of epidural was 67% (n = 273). Women with well palpable spinous process were 3.3 times more likely to have a successful first attempt placement irrespective of the provider experience or BMI [3.39 (1.77-6.51), P < 0.001]. The time to placement was shorter in patients with good anatomical landmarks [1.58 (1.20-2.07), P < 0.001) and when performed by a trainee who had performed a minimum of 20 epidural procedures [1.57 (1.26-1.94), P < 0.001).

CONCLUSION

Inability to palpate the spinous process contributes to multiple attempts at epidural placement when performed by a trainee.

Preliminary findings and outcomes associated with the use of a continuous spinal protocol for labor pain relief following accidental dural puncture

BACKGROUND

Various interventions have shown promise in reducing complications following accidental dural puncture. However, these have yet to be studied as a single, comprehensive protocol. The aim of this study is to compare outcomes associated with the use of a continuous spinal protocol for labor pain relief versus resiting the epidural catheter following accidental dural puncture.

METHODS

We reviewed the charts of patients managed via our continuous spinal protocol and compared this group with patients for whom the epidural was resited following accidental dural puncture during the 5-year period prior to implementing our protocol. We assessed incidence of postdural puncture headache, epidural blood patch, frequency of catheter replacement, use of pressors, verbal pain scores at 0, 1, 2, 3, 4 hours following catheter placement, infection rates (meningitis/epidural abscess) and mode of delivery.

RESULTS

There were 129 women in the continuous spinal protocol group and 52 in the resited epidural group. The incidence of postdural puncture headache was lower in the continuous spinal group versus the resited epidural group (21.7% vs 67.3%, p<0.001), and the incidence of epidural blood patch was lower in the continuous spinal group versus the resited epidural group (12.4% vs 50.0%, p<0.001). Verbal pain scores were consistently lower in the continuous spinal group compared with the resited epidural group at all time intervals studied.

CONCLUSION

Patients managed via this continuous spinal protocol had significantly lower incidence of postdural puncture headache and epidural blood patch with more effective labor analgesia following accidental dural puncture.

Epidural test dose in obstetric patients: should we still use it?

PURPOSE OF REVIEW

As the application of a test dose after epidural catheter insertion in obstetrics has recurrently been associated with serious adverse events affecting both maternal and foetal outcomes, the question whether to test or not remains a controversial issue.

RECENT FINDINGS

Present guidelines do not provide clear recommendations in this regard and several recent surveys indicate a heterogeneity in clinical routine.

SUMMARY

Physiological alterations during pregnancy and labour restrict the use and also the validity of traditional test agents. Epinephrine is not appropriate to detect a vascular insertion in labour and the application of a local anaesthetic test dose may lead to dose-dependent fatal consequences should the catheter be intrathecal, due to an increased sensitivity in parturients. Given the current practice of opioid-amended-low-concentration epidurals, the waiving of a test dose results at worst in a failed epidural, a stark contrast to the potentially severe to fatal complications of a 'traditional' test dose. Hence, an originally preventive measure providing potentially more harm than the consequences of the situation aimed to prevent, should not be recommended. A simple fractionated administration of the initial analgesic dose seems reasonable though.

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

BACKGROUND

Our 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).

METHODS

A 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.

RESULTS

Our 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.

CONCLUSIONS

Conventional 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.

Need for additional anesthesia after single injection spinal analgesia for labor: a retrospective cohort study

BACKGROUND

There is little information about the use and efficacy of single injection spinal blocks for labor analgesia; specifically, how frequently subsequent analgesia or anesthesia is needed. This study determined how frequently an additional anesthetic intervention was needed in women who received single injection spinal analgesia.

METHODS

This retrospective study examined electronic medical records to find all single injection spinal analgesic blocks for labor analgesia over a 14-year (2003-2016) period. Patient and block characteristics and patient outcomes were recorded. The primary outcome was need for an additional anesthetic intervention following single injection spinal for labor analgesia.

RESULTS

Four-hundred-and-twenty-eight patients received single injection spinal blocks for labor and 60 (14.0%) needed an additional anesthetic either for labor analgesia (n=49) or an unexpected procedure (n=11). Two of these (0.5%) required general anesthesia. Parity of zero (nulliparous), a low cervical dilation at the time of the spinal injection, and induction of labor status, were associated with an increased risk of needing an additional anesthetic intervention.

CONCLUSIONS

This retrospective review provides evidence that single injection spinal anesthesia may be used for multiparous women with spontaneous labor and more advanced cervical dilation.

Successful treatment of a recurrent post-dural puncture headache with an epidural blood patch 18 months after the initial dural puncture

Inadvertent dural puncture is a recognised complication of epidural insertion. Parturients are at increased risk of developing a post-dural puncture headache, which can be debilitating for a mother caring for a newborn infant. Epidural blood patch is an effective treatment in patients presenting acutely with post-dural puncture headaches but its efficacy in those with delayed presentation or with late recurrent post-dural puncture headache is less clear. We present the case of a woman with a recurrent post-dural puncture headache who was successfully treated with an epidural blood patch 18 months after the initial dural puncture. Patients who develop post-dural puncture headaches may remain symptomatic for some time and an epidural blood patch may be beneficial, following appropriate investigation.

THE COMPLICATIONS OF SPINAL ANESTHESIA IN OBSTETRIC AND GYNECOLOGICAL SURGICAL PROCEDURES

Background: The proper use of spinal anesthesia in surgical procedures will minimize patient’s referral. The objectives of the study were to determine the immediate and late complications of spinal anesthesia in obstetric and gynecological surgical procedures in our population. Material and Methods: This cross-sectional study was conducted in the Department of Gynecology and Obstetrics, Moulvi Ameer Shah Memorial Hospital, Peshawar, Pakistan from January 2014 to December 2014. Sample size was 790, selected through consecutive sampling technique. All routine and emergency obstetrical and gynecological cases were included. The exclusion criteria were those having hypotension, shock, coagulopathy, prolonged surgeries, patient’s refusal and local spinal disease. The demographic variables were; number of attempts, failure of anesthesia, vomiting, hypotension, respiratory problems, pain, Puncture site pain, and post dural puncture headache. All variables being categorical were analyzed by frequency and percentages using SPSS Version 16.0. Results: Out of 790 obstetrics and gynecology patients undergoing spinal anesthesia, there were 752 (95.2%) patients anaesthetized on first attempt whereas 38 (4.8%) required >1 attempts. Spinal anesthesia failed in 17 (2.1%) cases, partially failed in 15(1.9%). Post-operative mild hypotension was observed in 25 (3.1%) patients and severe hypotension in 4 (0.5%) cases. Respiratory problems were noted among 12 (1.9%). Patient’s Post-operative pain was observed in 28 (3.5%) patients. Nausea and vomiting were noted in 68 patients (8.6%).Late complications include post-operative mild to moderate pain in 65 (8.2%), severe in 15 (1.9%). Puncture site pain was observed in 8 (1.0%) of patients. Severe post dural puncture headache was noted in 3 (.38%). Conclusion: Spinal anesthesia in obstetric and gynecological surgical patients is easy to administer, safer and effective.

Repeat epidural blood patch at the level of unintentional dural puncture and its neurologic complications: a case report

BACKGROUND

Autologous epidural blood patch (AEBP) is effective for post-dural-puncture headache (PDPH). In some cases, repeat procedures are required for complete cure. In rare instances, severe adverse effects can occur. We present a case of neurologically complicated AEBPs, one of which was performed at the interspace of unintentional dural puncture (UDP).

CASE PRESENTATION

A 40-year-old primigravida sustained UDP at the L2-3 interspace during combined spinal-epidural anesthesia for a scheduled cesarean section. She developed PDPH and underwent a single AEBP at L3-4. The PDPH recurred and she required another AEBP at L2-3, after which she reported radicular pains. A diagnosis of subdural hematoma and adhesive arachnoiditis was made. Her symptoms partially resolved in the following months.

CONCLUSION

It may be prudent to reconsider the use of repeated AEBP and to avoid the interspace of UDP. A thorough evaluation is warranted to exclude treatable lesions when adverse effects occur.

Obstetric anaesthesia: what a neurologist needs to know

Neurologists are often consulted to see women postpartum who are having difficulties involving the lower extremities; weakness, numbness and pain. Many of these women have received labour analgesia. Often, there is limited understanding by the neurologist of how these procedures are performed, why a neuraxial technique is chosen and their potential complications. This case-based review will explain the differences in the neuraxial procedures: epidural, spinal and combined spinal epidural; their advantages and disadvantages, why one technique might be chosen over another, contraindications as well as procedural risks.

Minimally invasive spinal anesthesia for cesarean section in maternal anticoagulation therapy: a randomized controlled trial

BACKGROUND

Anticoagulant therapy during pregnancy is widely used due to the increasing awareness of maternal hypercoagulability. Few studies have reported the use of minimally invasive spinal anesthesia in these parturients. The objective of this study was to evaluate the safety and feasibility of minimally invasive spinal anesthesia in parturients with anticoagulation therapy undergoing cesarean section.

METHODS

This was a randomized, controlled study conducted in 239 parturients using anticoagulants and undergoing selective cesarean section. 37 parturients withdrew, and finally parturients received spinal anesthesia using 27gauge pen type fine spinal needles (experimental group, n = 110) and 22gauge traditional spinal needles (control group, n = 92). The primary efficacy outcomes included low back pain (LBP) and postdural puncture headache (PDPH) after delivery. Secondary efficacy outcomes included visual analogue scale during subarachnoid puncture (VASdural), difference between visual analogue scale (VAS) during peripheral venipuncture and VASdural (∆VAS), VAS of back puncture point 24, 48 and 72 h after operation (VASdural-24 h, VASdural-48 h and VASdural-72 h, respectively), maternal satisfaction and hospitalization stay.

RESULTS

No parturient had PDPH and was suspected with spinal or intracranial haematoma in two groups. There was no significant difference in VASlbp-24 h, VASlbp-48 h and VASlbp-72 h (P = 0.056; P = 0.813; P = 0.189, respectively) between two groups. In experimental group, VASdural (P = 0.017), ∆VAS (P = 0.001) and VASdural-24 h (P < 0.0001) were lower, whereas maternal satisfaction was higher (P = 0.046). There was no significant difference in VASdural-48 h, VASdural-72 h, urination function, strength recovery and hospitalization stay (P = 0.069; P = 0.667; P = 0.105; P = 0.133; P = 0.754, respectively) between the two groups.

CONCLUSIONS

Minimally invasive spinal anesthesia provided lower VASdural, VASdrual-24 h and a higher maternal satisfaction. Hence, it is considered as a safe, reliable and reasonable option for cesarean section parturients during maternal anticoagulation therapy with normal platelet count and coagulation time.

TRIAL REGISTRATION

This study was registered at www.ClinicalTrials.gov at November 11th, 2016 ( NCT02987192 ).

The Impact of Spinal Needle Selection on Postdural Puncture Headache: A Meta-Analysis and Metaregression of Randomized Studies

BACKGROUND AND OBJECTIVES

Potentially broadened indications for spinal anesthesia require increased understanding of the risk factors and prevention measures associated with postdural puncture headache (PDPH). This review is designed to examine the association between spinal needle characteristics and incidence of PDPH.

METHODS

Meta-analysis and metaregression was performed on randomized controlled trials to determine the effect of needle design and gauge on the incidence of PDPH after controlling for patient confounders such as age, sex, and year of publication.

RESULTS

Fifty-seven randomized controlled trials (n = 16416) were included in our analysis, of which 32 compared pencil-point design with cutting-needle design and 25 compared individual gauges of similar design. Pencil-point design was associated with a statistically significant reduction in incidence of PDPH (risk ratio, 0.41; 95% confidence interval, 0.31-0.54; P < 0.001; I = 29%) compared with cutting needles among studies that assessed both design types. Subgroup analysis among obstetric and nonobstetric procedures yielded similar results. After adjustment for significant covariates, metaregression analysis among all 57 included trials revealed a significant correlation between needle gauge and rate of PDPH among cutting needles (slope = -2.65, P < 0.001), but not pencil-point needles (slope = -0.01, P = 0.819).

CONCLUSIONS

Pencil-point needles are associated with significantly lower incidence of PDPH compared with the cutting-needle design. Whereas a significant relationship was noted between needle gauge and PDPH for cutting-needle design, a similar association was not shown for pencil-point needles. Providers may consider selection of larger-caliber pencil-point needle to maximize technical proficiency without expensing increased rates of PDPH.

Insertion of an intrathecal catheter following a recognised accidental dural puncture reduces the need for an epidural blood patch in parturients: an Australian retrospective study

BACKGROUND

There is no clear consensus about how best to prevent post-dural puncture headache (PDPH) following an accidental dural puncture in parturients. Our primary objective was to investigate whether the insertion of an intrathecal catheter following accidental dural puncture reduces the incidence of PDPH and therapeutic epidural blood patch.

METHODS

Anaesthetic records from January 2009 to December 2015 were reviewed retrospectively and parturients who had an accidental dural puncture and/or PDPH were identified. Data from those with a recognised dural puncture in whom an intrathecal catheter was inserted at the time of accidental dural puncture (ITC group) were compared to those without an intrathecal catheter (non-ITC group), as were outcomes of patients with an intrathecal catheter for ≥24 hours compared to <24 hours.

RESULTS

Of 94 recognised accidental dural punctures, 66 were in the ITC group (37 for ≥24 h) and 28 in the non-ITC group. In the ITC group, 22 (33.3%) required an epidural blood patch in comparison to 19 (67.9%) in the non-ITC group (P <0.01, 95% CI 12.5 to 52.0). In the ITC group, 62 (93.9%) developed PDPH in comparison to 28 (100%) in the non-ITC group (P=0.186, 95% CI -6.55 to 14.57). Intrathecal catheter insertion for ≥24 h obviated the need for an epidural blood patch in 28 (75.7%) parturients, compared to 13 (59.1%) if <24 h (P=0.184, 95% CI -7.08 to 39.72).

CONCLUSION

Inserting an intrathecal catheter after a recognised accidental dural puncture significantly reduced the need for an epidural blood patch.

Current Practice in Obstetric Anesthesia and Analgesia in Public Hospitals of Greece: A 2016 National Survey

Aims:

This descriptive survey was to evaluate the use of regional anesthesia in obstetrics in Greek public hospitals.

Methods:

The survey was conducted between March and August 2016. A structured questionnaire was sent to 50 anesthesia departments in Greek public hospitals with obstetric units.

Results:

The response rate was 94%. Data corresponding to 9475 cesarean and 8155 vaginal deliveries were collected. Regional anesthesia was used in 69.2% of all cesareans, with single shot spinal being the most popular (44.3% of all cesareans). Combined spinal-epidural anesthesia was used in 18.1% of all cesareans (35.1% in hospitals of Athens versus 7.9% outside Athens, p<0.001). Post-cesarean analgesia was applied with simple analgesics and systematic opioids (78.6%). Long-acting spinal opioids were rarely used (4.4% of spinal and spinal/epidurals). Labor epidural analgesia was applied in 19.1% of all vaginal deliveries (30.3% in Athens versus 13.1% outside Athens, p<0.001). Paracetamol and pethidine represented the standard labor analgesics in 48.9% and 55.3% of all hospitals. Intravenous remifentanil was used in 10.6% of hospitals (50% in Athens versus 2.5% outside Athens, p=0.002). In 48.9% of hospitals, mainly outside Athens, the anesthesiologists did not get involved in labor analgesia.

Conclusion:

Regional anesthesia is the most common practice for cesareans in Greek public hospitals; however, the percentage of general anesthesia remains high. In addition, the use of labor epidural analgesia is limited in hospitals outside Athens.

Effectiveness and safety of moderate-intensity aerobic water exercise during pregnancy for reducing use of epidural analgesia during labor: protocol for a randomized clinical trial

BACKGROUND

Epidural analgesia during labor can provide effective pain relief, but can also lead to adverse effects. The practice of moderate exercise during pregnancy is associated with an increased level of endorphins in the blood, and this could also provide pain relief during labor. Aerobic water exercises, rather than other forms of exercise, do not negatively impact articulations, reduce edema, blood pressure, and back pain, and increase diuresis. We propose a randomized controlled trial (RCT) to evaluate the effectiveness and safety of a moderate water exercise program during pregnancy on the need for epidural analgesia during labor.

METHODS

A multi-center, parallel, randomized, evaluator blinded, controlled trial in a primary care setting. We will randomised 320 pregnant women (14 to 20 weeks gestation) who have low risk of complications to a moderate water exercise program or usual care.

DISCUSSION

The findings of this research will contribute toward understanding of the effects of a physical exercise program on pain and the need for analgesia during labor.

TRIAL REGISTRATION

ISRCTN Registry identifier: 14097513 register on 04 September 2017. Retrospectively registered.

Labor Epidural Intolerance Due to a Congenitally Narrowed Spinal Canal

Reports exist of severe upper back pain of unknown etiology after administration of large volumes into the epidural space. We present a case of an otherwise healthy parturient who developed severe upper back and neck pain after receiving only a small volume of epidural medication. Magnetic resonance imaging revealed a congenitally narrowed spinal canal because of short pedicle syndrome. Epidural injectate occupies and compresses a percentage of the spinal canal and its neuronal contents. This may result in pain and epidural intolerance when continued injectate reaches a critical point, a threshold that is lower with shortened pedicles or congenital spinal stenosis. We believe a similar mechanism may explain the pain that patients sometimes experience after administration of large epidural volumes.

Pain Management in Obstetrics

Critical care clinicians may be called on to care for a laboring woman. Comprehension of the anatomic changes associated with pregnancy, and labor and birth, is essential. A working knowledge of the current options for pain management in labor, both pharmacologic and nonpharmacologic, is necessary to facilitate patient-centered care. Pharmacologic options include intravenous or intramuscular agents, inhalational agents, and neuraxial anesthesia. Each modality has contraindications, risks, and benefits that must be considered when choosing the most appropriate method.

Raman Spectroscopy Differentiates Each Tissue from the Skin to the Spinal Cord: A Novel Method for Epidural Needle Placement?

BACKGROUND

Neuraxial anesthesia and epidural steroid injection techniques require precise anatomical targeting to ensure successful and safe analgesia. Previous studies suggest that only some of the tissues encountered during these procedures can be identified by spectroscopic methods, and no previous study has investigated the use of Raman, diffuse reflectance, and fluorescence spectroscopies. The authors hypothesized that real-time needle-tip spectroscopy may aid epidural needle placement and tested the ability of spectroscopy to distinguish each of the tissues in the path of neuraxial needles.

METHODS

For comparison of detection methods, the spectra of individual, dissected ex vivo paravertebral and neuraxial porcine tissues were collected using Raman spectroscopy (RS), diffuse reflectance spectroscopy, and fluorescence spectroscopy. Real-time spectral guidance was tested using a 2-mm inner-diameter fiber-optic probe-in-needle device. Raman spectra were collected during the needle's passage through intact paravertebral and neuraxial porcine tissue and analyzed afterward. The RS tissue signatures were verified as mapping to individual tissue layers using histochemical staining and widefield microscopy.

RESULTS

RS revealed a unique spectrum for all ex vivo paravertebral and neuraxial tissue layers; diffuse reflectance spectroscopy and fluorescence spectroscopy were not distinct for all tissues. Moreover, when accounting for the expected order of tissues, real-time Raman spectra recorded during needle insertion also permitted identification of each paravertebral and neuraxial porcine tissue.

CONCLUSIONS

This study demonstrates that RS can distinguish the tissues encountered during epidural needle insertion. This technology may prove useful during needle placement by providing evidence of its anatomical localization.