Accidental dural puncture and post dural puncture headache in obstetric anaesthesia: presentation and management: a 23-year survey in a district general hospital

Efficacy of therapies for post dural puncture headache

PURPOSE OF REVIEW

Clinical management of postdural puncture headache (PDPH) remains an interdisciplinary challenge with significant impact on both morbidity and quality of life. This review aims to give an overview of the most recent literature on prophylactic and therapeutic measures and to discuss novel findings with regard to currently published consensus practice guideline recommendations.

RECENT FINDINGS

Although current evidence does not support a recommendation of any specific prophylactic measure, new data is available on the use of intrathecal catheters to prevent PDPH and/or to avoid invasive procedures. In case of disabling or refractory symptoms despite conservative treatments, the epidural blood patch (EBP) remains the therapeutic gold standard and its use should not be delayed in the absence of contraindications. However, recent clinical studies and meta-analyses provide additional findings on the therapeutic use of local anesthetics as potential noninvasive alternatives for early symptom control.

SUMMARY

There is continuing research focusing on both prophylactic and therapeutic measures offering promising data on potential alternatives to invasive procedures, although there is currently no treatment option that comes close to the effectiveness of an EBP. A better understanding of PDPH pathophysiology is not only necessary to identify new therapeutic targets, but also to recognize patients who benefit most from current treatments, as this might enhance their therapeutic efficacy.

Neuraxial Anesthesia during the COVID-19 Pandemic: Report from a Large Academic Medical Center

OBJECTIVE

 Three primary neuraxial techniques reduce labor pain: epidural, dural puncture epidural (DPE), and combined spinal-epidural (CSE). This study aims to determine whether neuraxial analgesia techniques changed after the onset of the coronavirus disease 2019 (COVID-19) pandemic. Given that a dural puncture confirms neuraxial placement, we hypothesized that DPE was more frequent in women with concerns for COVID-19.

STUDY DESIGN

 A single-center retrospective cohort study comparing neuraxial analgesia techniques for labor and delivery pain management before and after the onset of the COVID-19 pandemic and in patients with and without SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) at a maternity hospital in Dallas, Texas, with a large delivery service. Statistical analyses included the Chi-square test for categorical and Kruskal-Wallis test for nonparametric ordinal comparisons. The Cochran-Mantel-Haenszel test was used to assess the association between neuraxial technique and accidental dural puncture or postdural puncture headache.

RESULTS

 Of 10,971 patients who received neuraxial analgesia for labor, 5,528 were delivered in 2019 and 5,443 in 2020. Epidural analgesia was the most common neuraxial technique for labor pain in 2019 and 2020. There was no difference in the frequency of neuraxial analgesia techniques or the rates of accidental dural puncture or postdural puncture headaches comparing all deliveries in 2019 to 2020. Despite a significant increase in DPEs relative to epidurals in the SARS-CoV-2-positive group compared with the SARS-CoV-2-negative group in 2020, there was no significant difference in postdural puncture headaches or accidental dural punctures.

CONCLUSION

 The advantages of a DPE, specifically the ability to confirm epidural placement using a small gauge spinal needle, likely led to an increase in the placement of this neuraxial in SARS-CoV-2-positive patients. There was no effect on the frequency of postdural puncture headaches or accidental dural punctures within the same period.

KEY POINTS

· Epidural analgesia was the most common neuraxial technique for labor pain management.. · Dural puncture epidural placements increased in SARS-CoV-2-positive patients.. · Rates of postdural puncture headaches and accidental dural puncture after neuraxial placement did not change..

Post-caesarean Section Headache: A Case Report of Post-dural Puncture Headache and Cerebral Venous Thrombosis Following Epidural Anaesthesia

Post-dural puncture headache (PDPH) is a common complication of epidural and spinal anaesthesia in obstetric medicine. In rare cases, PDPH can be associated with complications such as cerebral venous thrombosis (CVT) as well. We discuss a recent case of a young female who developed PDPH and CVT concurrently after undergoing epidural anaesthesia for initially uncomplicated labour and delivered via an emergency caesarean section. She developed an orthostatic headache a few hours post administration of the epidural anaesthetic, which was initially treated as a suspected PDPH by giving simple analgesia and caffeine. Her symptoms did not improve and she underwent further neuroimaging, which revealed the development of a CVT. Despite the prompt administration of enoxaparin, the headache persisted and did not respond to increased doses of analgesia. After deliberation and inter-departmental discussion, an epidural blood patch was performed, leading to the prompt resolution of the headache. This report highlights a rare concurrence of PDPH and CVT, causing a diagnostic dilemma that resulted in treatment delays for the patient. Treating both conditions raises difficult practical questions, especially regarding the use of an epidural blood patch as opposed to anticoagulation. Given the risk of fatal complications such as venous cerebral infarction, seizures, and subdural hematoma, prompt treatment of both PDPH and CVT is strongly recommended. The multifactorial mechanism by which CVT develops with intracranial hypotension and PDPH also makes it essential for clinicians to keep an open mind when managing post-caesarean headaches, requiring inter-departmental cooperation to ensure optimal patient outcomes.

Prophylactic effect of chamomile on post-dural puncture headache in women undergoing elective cesarean section: A randomized, double blind, placebo-controlled clinical trial

BACKGROUND

Post-dural puncture headache (PDPH) is a common complication after spinal anesthesia, affecting patient recovery. This study evaluated the prophylactic effect of topical chamomile ointment on PDPH in women undergoing elective cesarean section.

METHODS

In a randomized, double-blind, placebo-controlled clinical trial 148 pregnant women were randomized into two parallel groups and received 3cc of the chamomile or the placebo ointment on the forehead of the participants 20 minutes before the start of spinal anesthesia, and then 2 and 4 hours after that. The primary outcomes were the incidence rate of headache, and its severity assessed by a numeric rating scale (NRS), while secondary outcomes included analgesic consumption, frequency of nausea/vomiting, and adverse events.

RESULTS

Chamomile ointment exhibited significant preventive effects on PDPH incidence compared to placebo. The chamomile group demonstrated lower rates of PDPH at 6 hours (3.5% vs. 7.18%, p = 0.021) and 12 hours (7.6% vs. 20%, p = 0.028) after spinal anesthesia. Analgesic consumption, frequency of nausea/vomiting, and adverse events were comparable between the groups.

CONCLUSION

Topical chamomile ointment demonstrated significant preventive effects on PDPH incidence compared to placebo. Chamomile ointment could be a promising adjunctive approach to prevent PDPH, enhancing patient comfort and potentially reducing the need for analgesics. Further investigation is needed to explore its mechanisms and broader applications.

Differential efficacy with epidural blood and fibrin patches for the treatment of post-dural puncture headache

BACKGROUND

Accidental dural puncture (ADP) is the most frequent major complication when performing an epidural procedure in obstetrics. Consequently, loss of pressure in the cerebrospinal fluid (CSF) leads to the development of post-dural puncture headache (PDPH), which occurs in 16%-86% of cases. To date, the efficacy of epidural fibrin patches (EFP) has not been evaluated in a controlled clinical trial, nor in comparative studies with epidural blood patches (EBP).

METHODS

The objective of the present study was to compare the efficacy of EFP with respect to EBP for the treatment of refractory accidental PDPH. This prospective, randomized, open-label, parallel, comparative study included 70 puerperal women who received an EBP or EFP (35 in each group) after failure of the conventional analgesic treatment for accidental PDPH in a hospital.

RESULTS

A higher percentage of women with EFP than EBP achieved complete PDPH relief after 2 (97.1% vs. 54.3%) and 12 h (100.0% vs. 65.7%) of the patch injection. The percentage of patients who needed rescue analgesia was significantly lower with EFP after 2 (2.9% vs. 48.6%) and 12 h (0.0% vs. 37.1%). After 24 h, PDPH was resolved in all women who received EFP. The recurrence of PDPH was reported in one woman from the EBP group (2.9%), who subsequently required a second patch. The mean length of hospital stay was significantly lower with EFP (3.9 days) than EBP (5.9 days). Regarding satisfaction, the mean value (Likert scale) was significantly higher with EFP (4.7 vs. 3.0).

CONCLUSIONS

EFP provided better outcomes than EBP for the treatment of obstetric PDPH in terms of efficacy, safety, and patient satisfaction.

Handheld ultrasound-assisted versus palpation-guided combined spinal-epidural for labor analgesia: a randomized controlled trial

Preprocedural ultrasound assistance can enhance the efficacy of neuraxial anesthesia in obstetrics. We investigated whether the use of handheld ultrasound can shorten the procedural time of labor combined spinal-epidural (CSE) analgesia compared with conventional landmark-guided methods. Eighty-four women requesting labor analgesia were randomly assigned to either handheld ultrasound-assisted or palpation-guided CSE analgesia. Primary outcome was procedure time of the CSE analgesia. Secondary outcomes included identification time, performance time, number of needle manipulations required for epidural/spinal success, first-attempt success rate, periprocedural pain scores, the incidence of accidental dural puncture, and patient satisfaction. Total procedure time did not significantly differ between the ultrasound and palpation groups (median [IQR], 191.5 [167-224] vs. 204.5 [163-358] s; P = 0.442). However, the performance time was significantly shorter in the ultrasound group (134.5 [115-177] vs. 183 [129-296] s; P = 0.011), although identification time was longer in the ultrasound group (53 [41-72] vs. 30.5 [21-45] s; P < 0.001). The epidural success rate at first insertion attempt was higher in the ultrasound group (85.7% vs. 59.5%, P = 0.014). Preprocedural handheld ultrasound assistance resulted in equivalent total procedure times but reduced performance times and higher first-attempt success rates. Therefore, clinicians may consider this technique for labor CSE analgesia.Trial registration: NCT04759547.

Intranasal Lidocaine Administration via Mucosal Atomization Device: A Simple and Successful Treatment for Postdural Puncture Headache in Obstetric Patients

(1) Background: Postdural puncture headache (PDPH) remains a serious complication in obstetric patients. While the epidural blood patch represents the current gold standard in therapy, a growing number of alternative measures are thought to be beneficial for clinical management. The purpose of this study was to retrospectively analyze the efficacy of intranasal lidocaine administration to treat PDPH in obstetrics at our university hospital; (2) Methods: A retrospective analysis of the medical records of patients with PDPH has been performed focusing on the techniques of administration, dosing, treatment duration, impact on pain intensity as well as side effects of intranasal lidocaine; (3) Results: During the study period, 5610 obstetric patients received neuraxial anesthesia, of whom 43 (0.77%) developed PDPH. About one third of the patients with PDPH after spinal anesthesia (n = 8), epidural anesthesia (n = 5) or both (n = 2) were treated with intranasal lidocaine. Lidocaine was administered either via gauze compresses (GC, n = 4), a mucosal atomization device (MAD, n = 8) or with a second-line mucosal atomization device due to low gauze compress efficacy (n = 3). All patients treated with lidocaine refused the epidural blood patch. Nebulization of lidocaine resulted in a significant reduction in pain intensity after the first dose (p = 0.008). No relevant side effects developed except sporadic temporal pharyngeal numbness. The utilization of the mucosal atomization device averted the necessity for an epidural blood patch, whether employed as the primary or secondary approach; (4) Conclusions: Our data imply that the mucosal atomization device enhances the efficacy of intranasal lidocaine administration in obstetric patients suffering from PDPH.

Epidural Analgesia Is Associated With Reduced Inpatient Opioid Consumption and Length of Stay After Wilms Tumor Resection

INTRODUCTION

Wilms' tumor (WT) is the most common renal malignancy in children and requires an extensive laparotomy for resection. Epidural analgesia (EA) is commonly used in postoperative pain management, but previous literature suggests it may prolong length of stay (LOS). We hypothesized that EA is associated with prolonged LOS but decreased postoperative opioid use in children undergoing WT resection.

MATERIALS AND METHODS

A retrospective chart review was performed for all WT patients who underwent nephrectomy between January 1, 1998, and December 31, 2018, at a tertiary children's hospital. Patients with incomplete records, bilateral WT, caval or cardiac tumor extension, or intubation postoperatively were excluded. Outcomes included postoperative opioid consumption measured in oral morphine equivalents per kilogram, receipt of opioid prescription at discharge, and postoperative LOS. Mann-Whitney and multivariable regression analyses were performed.

RESULTS

Overall, 46/77 children undergoing WT resection received EA. Children with EA used significantly less inpatient opioids than children without EA (median 1.0 vs. 3.3 oral morphine equivalents per kilogram; P < 0.001). Comparing patients with EA to patients without, there was no significant difference in opioid discharge prescriptions (57% vs. 39%; P = 0.13) or postoperative LOS (median 5 d vs. 6 d; P = 0.10). Controlling for age and disease stage, EA was associated with shorter LOS by multivariable regression (coefficient -0.73, 95% confidence interval: -1.4, -0.05; P = 0.04).

CONCLUSIONS

EA is associated with decreased opioid use in children without an associated increase in postoperative LOS following WT resection. EA should be considered as part of multimodal pain management for children undergoing WT resection.

Evidence-based clinical practice guidelines on postdural puncture headache: a consensus report from a multisociety international working group

INTRODUCTION

Postdural puncture headache (PDPH) can follow unintentional dural puncture during epidural techniques or intentional dural puncture during neuraxial procedures such as a lumbar puncture or spinal anesthesia. Evidence-based guidance on the prevention, diagnosis or management of this condition is, however, currently lacking. This multisociety guidance aims to fill this void and provide practitioners with comprehensive information and patient-centric recommendations to prevent, diagnose and manage patients with PDPH.

METHODS

Based on input from committee members and stakeholders, the committee cochairs developed 10 review questions deemed important for the prevention, diagnosis and management of PDPH. A literature search for each question was performed in MEDLINE (Ovid) on 2 March 2022. The results from each search were imported into separate Covidence projects for deduplication and screening, followed by data extraction. Additional relevant clinical trials, systematic reviews and research studies published through March 2022 were also considered for the development of guidelines and shared with contributors. Each group submitted a structured narrative review along with recommendations graded according to the US Preventative Services Task Force grading of evidence. The interim draft was shared electronically, with each collaborator requested to vote anonymously on each recommendation using two rounds of a modified Delphi approach.

RESULTS

Based on contemporary evidence and consensus, the multidisciplinary panel generated 50 recommendations to provide guidance regarding risk factors, prevention, diagnosis and management of PDPH, along with their strength and certainty of evidence. After two rounds of voting, we achieved a high level of consensus for all statements and recommendations. Several recommendations had moderate-to-low certainty of evidence.

CONCLUSIONS

These clinical practice guidelines for PDPH provide a framework to improve identification, evaluation and delivery of evidence-based care by physicians performing neuraxial procedures to improve the quality of care and align with patients' interests. Uncertainty remains regarding best practice for the majority of management approaches for PDPH due to the paucity of evidence. Additionally, opportunities for future research are identified.

Consensus Practice Guidelines on Postdural Puncture Headache From a Multisociety, International Working Group: A Summary Report

Importance

Postdural puncture headache (PDPH) can follow unintentional dural puncture during epidural techniques or intentional dural puncture during neuraxial procedures, such as a lumbar puncture or spinal anesthesia. Evidence-based guidance on the prevention, diagnosis, and management of this condition is, however, currently lacking.

Objective

To fill the practice guidelines void and provide comprehensive information and patient-centric recommendations for preventing, diagnosing, and managing PDPH.

Evidence Review

With input from committee members and stakeholders of 6 participating professional societies, 10 review questions that were deemed important for the prevention, diagnosis, and management of PDPH were developed. A literature search for each question was performed in MEDLINE on March 2, 2022. Additional relevant clinical trials, systematic reviews, and research studies published through March 2022 were also considered for practice guideline development and shared with collaborator groups. Each group submitted a structured narrative review along with recommendations that were rated according to the US Preventive Services Task Force grading of evidence. Collaborators were asked to vote anonymously on each recommendation using 2 rounds of a modified Delphi approach.

Findings

After 2 rounds of electronic voting by a 21-member multidisciplinary collaborator team, 47 recommendations were generated to provide guidance on the risk factors for and the prevention, diagnosis, and management of PDPH, along with ratings for the strength and certainty of evidence. A 90% to 100% consensus was obtained for almost all recommendations. Several recommendations were rated as having moderate to low certainty. Opportunities for future research were identified.

Conclusions and Relevance

Results of this consensus statement suggest that current approaches to the treatment and management of PDPH are not uniform due to the paucity of evidence. The practice guidelines, however, provide a framework for individual clinicians to assess PDPH risk, confirm the diagnosis, and adopt a systematic approach to its management.

Accidental dural puncture during epidural blood patch: a narrative review

Whilst performing an epidural blood patch (EBP) to treat post dural-puncture headache following accidental or intentional dural puncture, the risk of a subsequent accidental dural puncture (ADP) is commonly quoted as 1%. However, a recent review reported only three documented cases. It seems likely that this complication is more common than is acknowledged, yet there is a paucity of literature and an absence of any guidance as to how to proceed in practice. This review addresses three unanswered questions regarding ADP during EBP: what is the incidence; what are the immediate clinical consequences; and what is the optimal clinical management? The incidence may reasonably be estimated to be 0.5-1%. Even on large units, this complication will not be experienced by every consultant anaesthetist during their career. It is likely to occur 20-30 times per year in the United Kingdom, and in greater numbers in those countries with higher epidural rates. Immediately re-attempting an EBP at a different level may be a reasonable management approach which has high efficacy, and is without clear evidence of significant harm. However, the limited evidence means that the risks are poorly characterised, and more data may lead to alternative conclusions. There is uncertainty amongst obstetric anaesthetists about how to manage ADP during EBP. More data and pragmatic guidance, which evolves with further evidence, will ensure optimal care for patients suffering this compound iatrogenic complication.

The Importance of Initial Epidurography Prior to Any Drug Administration in Three-Day Adhesiolysis Procedure

Percutaneous epidural adhesiolysis (PEA) is a minimal invasive procedure to relieve sciatalgia caused by post lumbar surgery syndrome (PLSS). Fluoroscopic-guided contrast-epidurography is essential to ensure a safe procedure. We present a case of a 28-year-old male patient who underwent a PEA which was complicated by a dural puncture. We highlight the dangers of such complications and discuss associated risk factors.

Intrathecal haematoma after an epidural blood patch

SummaryThis case demonstrates a rare but potentially serious complication of an epidural blood patch (EBP). Intrathecal haematoma is a rare complication after an EBP and anaesthetists should be able to promptly identify and manage these patients to prevent long-term damage. This case also highlights the importance of informed consent according to the principles of the Montgomery judgement/principle of consent.

Role of MRI and CT in the Evaluation of Headache in Pregnancy and the Postpartum Period

Approximately 35% of acute headaches in pregnant women are secondary to an underlying condition. Headaches are also common in the postpartum period where they occur in 30% to 40% of patients. The majority of secondary headaches are due to hypertensive disorders: preeclampsia-eclampsia, posterior reversible encephalopathy syndrome, and acute arterial hypertension. Other causes include reversible cerebral vasoconstriction syndrome and pituitary apoplexy, as well as life-threatening conditions such as cerebral venous thrombosis. In this article, we review general recommendations for imaging the pregnant patients and discuss the imaging findings of common causes of headaches in pregnancy and the postpartum period.

Headaches in Pregnancy and Postpartum: ACOG Clinical Practice Guideline No. 3

PURPOSE

To provide updated evidence-based recommendations for the evaluation and treatment of primary and secondary headaches in pregnancy and postpartum.

TARGET POPULATION

Pregnant and postpartum patients with a history of or experiencing primary or new secondary headaches.

METHODS

This guideline was developed using an a priori protocol in conjunction with a writing team consisting of two specialists in obstetrics and gynecology appointed by the ACOG Committee on Clinical Practice Guidelines-Obstetrics and one external subject matter expert. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by two authors from the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements.

RECOMMENDATIONS

This Clinical Practice Guideline includes recommendations on interventions to prevent primary headache in individuals who are pregnant or attempting to become pregnant, postpartum, or breastfeeding; evaluation for symptomatic patients presenting with primary and secondary headaches during pregnancy; and treatment options for primary and secondary headaches during pregnancy and lactation. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence.

Recognized and unrecognized dural punctures in 12,981 labor epidurals: an audit of management

PURPOSE

Unintentional dural puncture (DP) and post-dural puncture headache (PDPH) continue to cause discomfort and disability in a small proportion of post-partum women. We report an audit of the management of recognized and unrecognized DP over 10 years.

METHODS

Clinical data were prospectively collected for women who experienced a recognized DP or developed symptoms following a neuraxial procedure. Details were documented regarding patient characteristics, the neuraxial procedure, symptoms reported, and epidural blood patches. We reported rates of recognized DP, unrecognized DP, PDPH, and blood patches performed. Data were presented as number (percent) and proportions of interest compared using Chi square analysis.

RESULTS

Between January 2009 and December 2018, 12,981 women utilized labor epidural analgesia. A recognized DP occurred in 131 (1.0%) and an unrecognized DP in 60 (0.5%), with unrecognized DPs comprising 31% of the total. Of 131 recognized punctures, 86 (66%) developed a PDPH. A total of 146 (1.1%) women experienced a PDPH. Of those, a blood patch was performed in 93 (64%). Intrathecal catheters were inserted for > 24 h in 43 (33%) women with a recognized DP. Of those, 33 (77%) developed a PDPH, compared to 53 (60%) of those without an intrathecal catheter in situ for > 24 h (P = 0.06).

CONCLUSIONS

Rates of DP were consistent with those reported by others. Unrecognized DP comprised a third of all DP, and systematic post-neuraxial follow-up is essential to identify these women. Epidural blood patch was performed in most women experiencing symptoms of PDPH.

Intracranial Subdural Hematoma Versus Postdural Puncture Headache Following Epidural Anesthesia: A Case Report

Headache is a relatively common complaint following dural puncture whether it is diagnostic (lumbar puncture) or unintentional (e.g., after epidural anesthesia). Although postdural puncture headache (PDPH) turns out to be the culprit in many cases, other serious etiologies should be ruled out such as postepidural intracranial subdural hematoma (PEISH). PEISH is usually overlooked because it is relatively rare and due to other frequent causes of headache (e.g., tension headache, migraine, and PDPH) being the main consideration. PEISH can be easily misdiagnosed as PDPH because of similar clinical manifestations. Herein, we report a case of this rare complication and demonstrate the major differences between PDPH and PEISH. This 27-year-old woman with intrauterine fetal death of dizygotic twins complained of severe headache immediately following receiving epidural anesthesia for labor induction. The patient was initially diagnosed with PDPH, and a blood patch was placed which provided complete resolution of the headache only for two days. Computed tomography of the brain revealed a small subdural hematoma over the left frontal convexity. Conservative management with close monitoring was recommended in this case due to the small size of the hematoma and absence of intracranial mass effect. An early follow-up CT scan showed complete and spontaneous resolution of the hematoma. In patients with recurrence or change in the pattern of the headache, persistence of headache despite treatment, and presence of neurological dysfunction following epidural anesthesia, suspicion of intracranial etiology must be raised. Therefore, knowledge of this condition and differentiating it from PDPH is necessary to avoid misdiagnosis and futile attempts of treatment.

Pressure monitoring devices may undetect epidural space: a report on the use of Compuflo® system for epidural injection

Lumbar epidural infiltration (EI) is a feasible procedure performed in pain therapy. Even though epidural analgesia is widely applied, it remains a blind technique, based on the operator's hand sensations, and it is associated with significant failure rate and several potential complications. Compuflo® (Compuflo, Milestone Scientific, Livingston, NJ) is a computerized injection pump which precisely detects the real time pressure at the tip of a Tuohy needle when placed in human tissues, thanks to a continuous fluid path. In our institution, we usually perform EI for chronic back pain guided by the Compuflo device, especially for expected difficult procedures. However, we report 6 false negative cases on a total number of 60 procedures in which the Compuflo system didn't meet the criteria of epidural space entry, even though the epidural space was actually reached. A mild pressure decrease (less than 50%) which lasted for more than 5 s was reported on the monitor, and the acoustic signal changed in a little bit lower sound, without a clear indication on stopping or not the needle advancement. This unspecific drop in monitored pressure gives false negatives using the Compuflo® system and may lead to excessive advancing of the needle. In conclusion, we consider the epidural pressure monitoring device Compuflo as a tool which may be able to ease the correct positioning of an epidural needle. The percentage of 10% false negative identifications of the epidural space in our case series however suggests more investigations on adequate or specific settings for this epidural system. In the meantime, in chronic pain patients, this anesthetic technique should only be used by experienced hands.

Did she have an epidural? The long-term consequences of postdural puncture headache and the role of unintended dural puncture

OBJECTIVE

This narrative literature review examines the long-term impact of postdural puncture headache (PDPH) in postpartum women following an unintended dural puncture (UDP) with a large bore needle commonly used for epidural catheter placement. It seeks to bridge the knowledge gap for the neurologist as to the mounting body of obstetric anesthesia literature on the development of chronic headache after PDPH with this unique needle.

BACKGROUND

Headache is the most common complication of dural puncture, and the risk is greatest in the parturient population. Preexisting risk factors for this population include youth and sex, and after UDP with a large bore needle, almost 70%-80% report a headache. Additionally, there appears to be a significant cohort who experience long-term, persistent headache after UDP.

METHODS

We performed a narrative review of literature using PubMed, searching terms that included long-term follow-up after UDP with a large bore needle in the postpartum population.

RESULTS

In women who had UDP with a large bore needle used for epidural catheter placement at delivery, the rate of chronic debilitating headache is around 30% in the months following delivery and may persist for up to a year or longer.

CONCLUSION

Based on the existing literature, we have mounting evidence that UDP with the large bore needle used to place an epidural catheter should be understood as a high-risk inciting event for the development of long-term headaches not simply a high risk of acute PDPH. Additionally, consideration should be given to stratifying the etiology of PDPH, based on needle type, and recognizing the entity of chronic PDPH, thus allowing for improvements in research and diagnosis.

Magnetic resonance imaging of cerebrospinal fluid spread in the epidural space and postdural puncture headache in obstetrics: A proof-of-concept study

BACKGROUND

Currently, performing an epidural blood patch (EBP) for postdural puncture headache (PDPH) remains a subjective clinical decision. An evidence-based protocol may be of value in identifying women at high risk of developing a severe PDPH.

OBJECTIVE

To investigate a potential correlation between the extent of CSF spread in the epidural space, as noted on Magnetic Resonance Imaging (MRI), and the likelihood of development of severe PDPH in obstetric patients.

DESIGN

A prospective double-blind quasi-observational study.

SETTING

Eight tertiary obstetric units, from NHS hospitals.

PATIENTS

Parturients with accidental dural puncture (ADP) underwent T1 and T2-weighted MRI scans of the brain and lumbar spine within 48 h after delivery. All women were followed up, daily, for 1 week.

MAIN OUTCOME MEASURES

For each woman, a PDPH severity score was calculated using a four-point Verbal Reporting Scale (none = 0, mild = 1, moderate = 2, severe = 3), with additional points awarded for visual, auditory and emetic symptoms. MRIs were reported by a neuroradiologist, blind to the patient details, using a predefined MRI score.

RESULTS

Twenty-two parturients were recruited; 86% (n=19) developed PDPH and 10 of these (53%) required an EBP. The median (range) time for the onset of PDPH was 24 (4 to 126) hours. The median (range) cumulative PDPH severity score was 10 (0 to 21), whereas, the median (range) MRI score was 2.5 (0 to 12). Spearman (rs) analysis identified a significant positive correlation (rs = 0.46; P = 0.024) between cumulative PDPH severity and MRI scores. Of all the radiological features identified in an MRI (lumbar dural shift, caudal brain displacement, epidural or intrathecal blood), the presence of intrathecal blood was most strongly correlated with PDPH severity (P = 0.043).

CONCLUSION

Following an ADP, the extent of CSF spread in the epidural space correlates with the severity of subsequent PDPH.

CLINICAL TRIAL NUMBER AND REGISTRY URL

ISRCTN14959004, https://www.isrctn.com/.

It.ÇÖs not always postdural puncture headache: a case report and note to the astute anesthesiologist

Dural puncture is either diagnosed by unexpectedly profound response to medication test dose or development of a postpartum postural headache. Epidural blood patch is the gold standard for treatment of PDPH when conservative management fails. However, postpartum headaches can be resistant to multiple epidural blood patches. In such cases, preexisting intracranial processes should be considered and ruled out. We report here the unique case of a pregnant patient who developed a resistant headache in the postpartum period related to an incidental intracranial aneurysm. Subsequent treatment with endovascular embolization adequately relieved her symptoms. Early surgical consultation and a multidisciplinary team approach involving neurology and neuroimaging is required for successful management of patients such as the one described here.

[Post-dural puncture headache]

Post-dural puncture headache belongs to the group of secondary headache disorders and is a typical complication of intended or unintended dural puncture. The main symptom is orthostatic headache, which can be accompanied by neurological symptoms such as diplopia depending on the extent of the cerebrospinal fluid leak. The course of this headache is predominantly benign, showing spontaneous improvement over a couple of days, although severe cases are described in the literature. The following article provides an overview of the current knowledge about the headache's pathophysiology, diagnostic work-up and therapy.

Post-dural puncture headache-a single-centre analysis in paediatric patients with and without SMA

AIM

To gather epidemiologic data on post-dural puncture headache (PDPH) after diagnostic or therapeutic lumbar puncture (LP) in children and adolescents with SMA as well as in a cohort of paediatric patients without SMA.

METHODS

We performed a retrospective, single-centre analysis via chart review and questionnaire. Patients were identified using the German procedure classification. Respective charts and SMArtCARE documentation forms (SMA patients) were reviewed concerning documentation of headaches fulfilling criteria of the IHS-classification for PDPH of 2004. Non-SMA patients received additional questionnaires.

RESULTS

We identified a total of 218 LPs in 95 patients. Of those 141 were performed in 22 patients with known SMA (mean age SMA patients 9.2 years; non-SMA patients 11.4 years). Following chart review, IHS criteria for PDPH were fulfilled in 6.9% of all procedures (3.5% in SMA patients; 13.0% in non-SMA patients; p = 0.008). Data from questionnaires of non-SMA patients confirmed this result (position dependent headache within 72 h after intervention in 13.0% of procedures).

CONCLUSION

The prevalence of PDPH after therapeutic LPs in our cohort of SMA patients was significantly lower than after LPs in the general paediatric cohort. Data of this retrospective analysis show a similar overall prevalence of PDPH in paediatric patients as reported in bigger adult cohorts.

Spinal subdural hematoma and subdural anesthesia following combined spinal-epidural anesthesia: a case report

Background

Subdural anesthesia and spinal subdural hematoma are rare complications of combined spinal-epidural anesthesia. We present a patient who developed both after multiple attempts to achieve combined spinal–epidural anesthesia.

Case presentation

A 21-year-old parturient, gravida 1, para 1, with twin pregnancy at gestational age 34^+ 5 weeks underwent cesarean delivery. Routine combined spinal–epidural anesthesia was planned; however, no cerebrospinal fluid outflow was achieved after several attempts. Bupivacaine (2.5 mL) administered via a spinal needle only achieved asymmetric blockade of the lower extremities, reaching T12. Then, epidural administration of low-dose 2-chlorprocaine caused unexpected blockade above T2 as well as tinnitus, dyspnea, and inability to speak. The patient was intubated, and the twins were delivered. Ten minutes after the operation, the patient was awake with normal tidal volume. The endotracheal tube was removed, and she was transferred to the intensive care unit for further observation. Postoperative magnetic resonance imaging suggested a spinal subdural hematoma extending from T12 to the cauda equina. Sensory and motor function completely recovered 5 h after surgery. She denied headache, low back pain, or other neurologic deficit. The patient was discharged 6 days after surgery. One month later, repeat MRI was normal.

Conclusions

All anesthesiologists should be aware of the possibility of SSDH and subdural block when performing neuraxial anesthesia, especially in patients in whom puncture is difficult. Less traumatic methods of achieving anesthesia, such as epidural anesthesia, single-shot spinal anesthesia, or general anesthesia should be considered in these patients. Furthermore, vital signs and neurologic function should be closely monitored during and after surgery.

[Post-dural puncture headache]

Post-dural puncture headache belongs to the group of secondary headache disorders and is a typical complication of intended or unintended dural puncture. The main symptom is orthostatic headache, which can be accompanied by neurological symptoms such as diplopia depending on the extent of the cerebrospinal fluid leak. The course of this headache is predominantly benign, showing spontaneous improvement over a couple of days, although severe cases are described in the literature. The following article provides an overview of the current knowledge about the headache's pathophysiology, diagnostic work-up and therapy.

The association between labour epidural case volume and the rate of accidental dural puncture

Accidental dural puncture is a recognised complication of labour epidural placement and can cause a debilitating headache. We examined the association between labour epidural case volume and accidental dural puncture rate in specialist anaesthetists and anaesthesia trainees. We performed a retrospective cohort study of labour epidural and combined spinal-epidural nerve blocks performed between 1 July 2013 and 31 December 2017 at Waitemata District Health Board, Auckland, New Zealand. The mean (SD) annual number of obstetric epidural and combined spinal-epidural procedures for high-case volume specialists was 44.2 (15.0), and for low-case volume specialists was 10.0 (6.8), after accounting for caesarean section combined spinal-epidural procedures. Analysis of 7976 labour epidural and combined spinal-epidural procedure records revealed a total of 92 accidental dural punctures (1.2%). The accidental dural puncture rate (95%CI) in high-case volume specialists was 0.6% (0.4-0.9%) and in low-case volume specialists 2.4% (1.4-3.9%), indicating probable skill decay. The odds of accidental dural puncture were 3.77 times higher for low- compared with high-case volume specialists (95%CI 1.72-8.28, p = 0.001). Amongst trainees, novices had a significantly higher accidental dural puncture complication rate (3.1%) compared with registrars (1.2%), OR (95%CI) 0.39 (0.18-0.84), p = 0.016, or fellows (1.1%), 0.35 (0.16-0.76), p = 0.008. Accidental dural puncture complication rates decreased once trainees progressed past the 'novice' training stage.

[Intranasal lidocaine atomization as novel and noninvasive treatment option for postdural puncture headache : Two case reports from obstetric anesthesiology]

Hintergrund

Der Postpunktionskopfschmerz („postdural puncture headache“ [PDPH]) stellt eine ernsthafte anästhesiologische Komplikation geburtshilflich behandelter Patientinnen dar. Führen konservativ-medikamentöse Therapieversuche nicht zu einer Symptomlinderung, empfehlen aktuelle Leitlinien die frühzeitige Durchführung eines epiduralen Blut-Patch. Als potenzielle Alternative wird die transnasale Blockade des Ganglion sphenopalatinum mittels Lokalanästhetika diskutiert.

Methode

In dieser Falldarstellung wird erstmals von einer Modifikation dieser Technik unter Anwendung eines Medikamentenzerstäubers („mucosal atomization device“ [MAD]) zur Therapie eines PDPH bei zwei geburtshilflichen Patientinnen berichtet. Über dieses Verfahren existieren bislang keine Erfahrungen aus der geburtshilflichen Anästhesiologie.

Ergebnisse

Die erste Patientin (25-jährige Zweitgravida, BMI 54,7 kg/m²) zeigte am ersten Tag nach Sectio caesarea in Spinalanästhesie einen ausgeprägten PDPH mit starker Übelkeit und Erbrechen. Bei der zweiten Patientin (32-jährige Drittgravida, BMI 27,3 kg/m²) kam es 4 Tage nach Spontanpartus unter Periduralanästhesie zu einer PDPH-bedingten Wiederaufnahme. Während konservative Maßnahmen sowie Therapieversuche mit Nichtopioidanalgetika und Koffein keinen hinreichenden Behandlungserfolg erzielten, führte die intranasale Lidocainapplikation mittels MAD zu einer unmittelbaren und persistierenden Linderung der Beschwerden. Von beiden Patientinnen wurde die Lidocaingabe sehr gut vertragen; sie konnten am Folgetag aus dem Krankenhaus entlassen werden.

Schlussfolgerung

Die vorgestellte nichtinvasive und einfach durchzuführende Maßnahme stellt eine wertvolle Ergänzung bisheriger Therapieoptionen und eine potenzielle Alternative zum epiduralen Blutpatch bei geburtshilflichen Patientinnen mit PDPH dar.

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.

[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.

Lower Glucose Level Associated With Increased Risk for Post-Dural Puncture Headache

OBJECTIVE AND BACKGROUND

Post-dural puncture headache is the most common significant adverse event following lumbar puncture. In this study, we investigated the possible systemic factors associated with risk for post-dural puncture headache (PDPH).

METHODS

We performed a retrospective cohort study in 969 patients who underwent diagnostic lumbar puncture following a standardized protocol. We compared the clinical and laboratory profiles of the post-dural puncture headache group and non-headache group. We also identified independent factors associated with the incidence of post-dural puncture headache.

RESULTS

A total of 48 patients (5%) reported headache; 12 of these patients (25%) received a therapeutic epidural blood patch and the remaining 36 patients improved with conservative treatment. After adjusting for other variables that could be related to PDPH, we found that the development of post lumbar puncture headache was independently associated with age (OR: 0.97, 95% CI: 0.95-0.99, P = .001) and serum glucose levels (OR: 0.98, 95% CI: 0.97-0.99, P = .008).When the patients were classified by age, serum glucose levels were persistently lower in patients with PDPH vs those patients without PDPH in all age groups, with more clearly significant differences observed in the elderly (age <30 years, 103.4 mg/dL vs 106.3 mg/dL, P = .716; >60 years, 111.8 mg/dL vs 137.3 mg/dL, P = .023).

CONCLUSIONS

Low glucose levels were inversely associated with risk for post-dural puncture headache. Patients with low serum glucose should be carefully monitored for headache after lumbar puncture.

Development and Evaluation of an Augmented Reality Ultrasound Guidance System for Spinal Anesthesia: Preliminary Results

Applications of ultrasound guidance for epidural injections are hindered by poor needle and epidural space visualization. This work presents an augmented reality (AR) ultrasound guidance system that addresses challenges in both needle visualization during navigation and epidural space identification for needle positioning. In this system, (i) B-mode ultrasound and the needle are visualized in a 3-D AR environment for improved navigation, and (ii) A-mode ultrasound, obtained from a custom-made single-element transducer housed at the needle tip, is used to identify the epidural space for improved needle positioning. Performance of the system was evaluated against ultrasound-only guidance in a phantom study with novice operators and an expert anesthesiologist. The procedure success rate was higher with the AR system (100%) than ultrasound-only guidance (57%). The AR system has the potential to improve procedure outcomes in terms of success rate, time, needle path-length and usability.

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.

Comparison between the Effects of Sumatriptan Versus Naratriptan in the Treatment of Postdural Puncture Headache in Obstetric Patients: A Randomized Controlled Trial

Background

Postdural puncture headache (PDPH) in the obstetric anesthesia practice is one of the most annoying, common, and important problems.

Aim

This comparative study was designed to assess the efficacy of naratriptan in relieving PDPH in parturients who gave birth by cesarean section under intrathecal anesthesia and to compare its efficacy with sumatriptan.

Settings and Design

One hundred and eighty-nine adult parturients who complained of PDPH in the first 3 days postpartum period were enrolled in this study. They were divided into three equal parallel groups of 63 each.

Materials and Methods

Group-1 controlled (C-group) received multivitamin tablets, Group-2 sumatriptan (S-group) received sumatriptan tablets and Group-3 naratriptan (N-group) received naratriptan tablets. The efficacy of naratriptan in relieving PDPH was studied and compared with that of sumatriptan. Incidences of complications of both drugs were also noted.

Statistical Analysis

The collected data were organized, tabulated, and statistically analyzed using SPSS software statistical computer package version 18 (SPSS Inc., USA).

Results

After the first 6 h, there were statistically significant differences between Groups S and N from one side and control group from the other side (P < 0.0001 and 0.001), respectively, and the difference between Group S and Group N was statistically significant (P = 0.004). After 12 h, there were statistically significant differences between Groups S and N from one side and the control group from the other side (P < 0.0001) and the difference between Group S and Group N was statistically significant (P = 0.002). After 72 h, there were statistically significant differences between Groups S and N from one side and control group from the other side (P < 0.001 and 0.009), respectively. The difference was nonsignificant between S and N group (P = 0.717).

Conclusion

The study revealed that anti-migraine drug naratriptan in combination with supportive treatment was effective in relieving PDPH in parturients.

Treatment of obstetric post-dural puncture headache. Part 2: epidural blood patch

The 2009-12 MBRRACE-UK report highlighted the deaths of two women in whom dural puncture had occurred during insertion of a labour epidural catheter. Despite suffering long-term headaches, neither woman was adequately followed-up after discharge from hospital. Death resulted from a cerebral vein thrombosis in one case and a subdural haematoma in the other. Due to significant variation in the treatment of obstetric post-dural puncture headache, an Obstetric Anaesthetists' Association working group was set up to produce evidence-based guidelines to guide clinicians. These guidelines have been condensed into two review articles. In this second review, the role of an epidural blood patch is discussed using a question and answer format.

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.

Neuraxial Regional Anaesthesia in Patients with Active Infection and Sepsis: A Clinical Narrative Review

Infection is considered to be a relative contraindication for regional anaesthesia. However, there is a paucity of articles addressing the topic of regional anaesthesia in patients with an active infectious process. Recent publications show a low incidence of infection (0.007% to 0.6%) of the central nervous system after neuraxial punctures in patients at risk of, or with ongoing bacteraemia, and a low incidence of infection after performing regional anaesthesia techniques in immunosuppressed patients, or patients with an actual infection. Therefore, some authors conclude that it seems that there is little justification to set strict contraindications regarding this indication and that the risk-benefit ratio should prevail. In addition, a low incidence of meningitis or abscesses after the lumbar puncture has been observed in patients with unsuspected and ongoing bacteraemia, or who were at risk of bacteraemia, when antibiotic therapy has been previously started. For viral infections, regional techniques seem to be safe, being applied in patients with HIV infection. The only established absolute contraindication for any type of regional anaesthesia technique is the infection at the puncture site. Debate persists if a neuraxial anaesthesia technique is to be performed in the course of sepsis with the origin away from the puncture site. In case of thoracic epidural anaesthesia and analgesia, experimental and clinical studies highlight their potential benefits in the systemic inflammatory response syndromes and founded sepsis, both in surgical and non-surgical patients. Finally, the anti-inflammatory and anti-infective effects of local anaesthetics and the basis of excessive inflammatory response are described, as the latter might be involved, in part, in the clinical outcomes.

Low-cost three-dimensional printed phantom for neuraxial anesthesia training: Development and comparison to a commercial model

METHODS

Anonymized CT DICOM data was segmented to create a 3D model of the lumbar spine. The 3D model was modified, placed inside a digitally designed housing unit and fabricated on a desktop 3D printer using polylactic acid (PLA) filament. The model was filled with an echogenic solution of gelatin with psyllium fiber. Twenty-two staff anesthesiologists performed a spinal and epidural on the 3D printed simulator and a commercially available Simulab phantom. Participants evaluated the tactile and ultrasound imaging fidelity of both phantoms via Likert-scale questionnaire.

RESULTS

The 3D printed neuraxial phantom cost $13 to print and required 25 hours of non-supervised printing and 2 hours of assembly time. The 3D printed phantom was found to be less realistic to surface palpation than the Simulab phantom due to fragility of the silicone but had significantly better fidelity for loss of resistance, dural puncture and ultrasound imaging than the Simulab phantom.

CONCLUSION

Low-cost neuraxial phantoms with fidelity comparable to commercial models can be produced using CT data and low-cost infrastructure consisting of FLOS software and desktop 3D printers.

Stable Physical Human-Robot Interaction Using Fractional Order Admittance Control

In the near future, humans and robots are expected to perform collaborative tasks involving physical interaction in various environments, such as homes, hospitals, and factories. Robots are good at precision, strength, and repetition, while humans are better at cognitive tasks. The concept, known as physical human-robot interaction (pHRI), takes advantage of these abilities and is highly beneficial by bringing speed, flexibility, and ergonomics to the execution of complex tasks. Current research in pHRI focuses on designing controllers and developing new methods which offer a better tradeoff between robust stability and high interaction performance. In this paper, we propose a new controller, fractional order admittance controller, for pHRI systems. The stability and transparency analyses of the new control system are performed computationally with human-in-the-loop. Impedance matching is proposed to map fractional order control parameters to integer order ones, and then the stability robustness of the system is studied analytically. Furthermore, the interaction performance is investigated experimentally through two human subject studies involving continuous contact with linear and nonlinear viscoelastic environments. The results indicate that the fractional order admittance controller can be made more robust and transparent than the integer order admittance controller and the use of fractional order term can reduce the human effort during tasks involving contact interactions with environment.