Changes in intracranial pressure associated with extradural anaesthesia

Effect of epidural anesthesia on the optic nerve sheath diameter in patients with pre-eclampsia: a prospective observational study

INTRODUCTION

Optic nerve sheath diameter (ONSD) reflects intracranial pressure and is increased in pre-eclampsia. Administrating a significant volume of epidural solution into the epidural space can potentially increase ONSD. We investigated the impact of epidural local anesthetic injection on ONSD in patients with pre-eclampsia.

METHODS

Patients with pre-eclampsia (n=11) and normotensive pregnant women (n=11) received de novo epidural anesthesia for cesarean delivery. We administered 21 mL of an epidural solution containing 2% lidocaine and 50 μg fentanyl into the lumbar epidural space in incremental doses. ONSD was measured at baseline, 3, 10, and 20 min after completing the epidural injection, after delivery, and at the end of surgery. Primary outcome was the change in ONSD from baseline to 3 min after epidural injection in patients with pre-eclampsia and normotensive pregnant women. Serial changes in the ONSD were analyzed using a linear mixed model.

RESULTS

At baseline and 3 min after epidural drug injection, ONSD was significantly larger in patients with pre-eclampsia than in normotensive mothers (5.7 vs 4.1 mm, p=0.001 and 5.4 vs 4.1 mm, p<0.001, respectively). However, there were no significant changes in ONSD at 3 min after injection from baseline in either group (p>0.999). Linear mixed model demonstrated that ONSD did not change after epidural anesthesia in either group (p=0.279 and p=0.347, respectively).

CONCLUSIONS

Despite a higher baseline ONSD in pre-eclampsia, epidural anesthesia did not further increase ONSD. Our findings indicate that epidural anesthesia can be safely administered in patients with pre-eclampsia at risk of increased intracranial pressure, without other intracranial pathology.

TRIAL REGISTRATION NUMBER

NCT04095832.

Hemianopia: A complication of epidural injection in a patient with arachnoid cyst - case report

Epidural injections are routinely used for short-term management of radicular pain and chronic low back pain. Prescription of this intervention, in the presence of intracranial abnormalities, is a topic of debate. Intracranial arachnoid cysts are cerebrospinal fluid-filled spaces, which are usually asymptomatic despite being a formidable size. As far as the authors know, there have been no cases depicted in indexed literature regarding asymptomatic supratentorial arachnoid cysts becoming symptomatic post undertaking of spinal epidural injections. We depict this phenomenon in a 53-year-old woman, who ultimately required a craniotomy to address their symptoms. Asymptomatic supratentorial arachnoid cysts can become symptomatic post undertaking of spinal epidural injections. In cases of known cranial arachnoid cysts with mass effect, the small risk that the cranial arachnoid cyst may become symptomatic during or after epidural injections should be a consideration and the patients should be informed of the potential associated risks.

Intracranial Pressure Evaluation in Swine During Full-Endoscopic Lumbar Spine Surgery

BACKGROUND

Neurological complications during full-endoscopic spine surgery (FESS) might be attributed to intracranial pressure (ICP) increase due to continuous saline infusion (CSI). Understanding CSI and ICP correlation might modify irrigation pump usage. This study aimed to evaluate invasive ICP during interlaminar FESS; correlate ICP with irrigation pump parameters (IPPs); evaluate ICP during saline outflow occlusion, commonly used to control bleeding and improve the surgeon's view; and, after durotomy, simulate accidental dural tear.

METHODS

Five swine were monitored, submitted to total intravenous anesthesia, and positioned ventrally. A parenchymal catheter was installed through a skull burr for ICP monitoring. Lumbar interlaminar FESS was performed until exposure of neural structures. CSI was used within progressively higher IPPs (A [60 mm Hg, 350 mL/minute] to D [150 mm Hg, 700 mL/minute]), and ICP was documented. During each IPP, different situations were grouped: intact dura with open channels (A1-D1) or occlusion test (A2-D2); dural tear with open channels (Ax1-Dx1) or occlusion test (Ax2-Dx2). ICP <20 mm Hg was defined as safe.

RESULTS

Basal average ICP was 8.1 mm Hg. Adjustment in total intravenous anesthesia or suspension of tests was necessary due to critical ICP or animal discomfort. It was safe to operate with all IPPs with opened drainage channels (A1-D1) even with dural tear (Ax1-Dx1). Several occlusion tests (A2-D2, Ax2-Dx2) caused ICP increase (e.g., 86.1 mm Hg) influenced by anesthetic state and hemodynamics.

CONCLUSIONS

During FESS, CSI might critically raise ICP. Keeping drainage channels open, with ideal anesthetic state, ICP remains safe even with high IPPs, despite dural tear. Drainage occlusions can quickly raise ICP, being even more severe with higher IPPs. Total intravenous anesthesia may protect from ICP increase and may allow longer drainage occlusion or higher IPPs.

Perioperative Care of the Patient with Eye Pathologies Undergoing Nonocular Surgery

The authors reviewed perioperative ocular complications and implications of ocular diseases during nonocular surgeries. Exposure keratopathy, the most common perioperative eye injury, is preventable. Ischemic optic neuropathy, the leading cause of perioperative blindness, has well-defined risk factors. The incidence of ischemic optic neuropathy after spine fusion, but not cardiac surgery, has been decreasing. Central retinal artery occlusion during spine fusion surgery can be prevented by protecting eyes from compression. Perioperative acute angle closure glaucoma is a vision-threatening emergency that can be successfully treated by rapid reduction of elevated intraocular pressure. Differential diagnoses of visual dysfunction in the perioperative period and treatments are detailed. Although glaucoma is increasingly prevalent and often questions arise concerning perioperative anesthetic management, evidence-based recommendations to guide safe anesthesia care in patients with glaucoma are currently lacking. Patients with low vision present challenges to the anesthesia provider that are becoming more common as the population ages.

Pressure-Volume Relationships in the Spinal Canal and Potential Neurological Complications After Epidural Fluid Injections

High-volume fluid injections into the spinal canal may lead to severe neurological complications. But when anatomical or pathological conditions in the spinal canal are unfavorable, even small volume epidural injections can cause dangerously high epidural, subarachnoid, and intracranial pressures or pressure gradients. Data obtained from the scientific literature and direct clinical observation are used to derive a first-order approximation of epidural, subarachnoid, and intracranial pressure responses to epidural fluid injections. Maximum allowable fluid volumes for single or multiple divided fluid injections over time are calculated. In the presence of spinal pathology, 10 ml of fluids may increase epidural pressure to &gt;100 mmHg. Injection speed &gt;4 ml per second may also generate dangerously high intraspinal and intracranial pressures. Intermitted bolus injections provide limited protection, but intraspinal pressures may rise very fast when a critical total injected volume is reached. Potential complications of increased intracranial pressures or large pressure waves include nerve palsies, tinnitus, blindness, stroke, and death. Spinal injections or endoscopy should be performed in an awake responsive patient or with direct cerebrospinal fluid pressure monitoring. A set of guidelines for epidural fluid management is given.

Regional Anesthesia for Lumbar Spine Surgery: Can It Be a Standard in the Future?

This paper is an overview of various features of regional anesthesia (RA) and aims to introduce spine surgeons unfamiliar with RA. RA is commonly used for procedures that involve the lower extremities, perineum, pelvic girdle, or lower abdomen. However, general anesthesia (GA) is preferred and most commonly used for lumbar spine surgery. Spinal anesthesia (SA) and epidural anesthesia (EA) are the most commonly used RA methods, and a combined method of SA and EA (CSE). Compared to GA, RA offers numerous benefits including reduced intraoperative blood loss, arterial and venous thrombosis, pulmonary embolism, perioperative cardiac ischemic incidents, renal failure, hypoxic episodes in the postanesthetic care unit, postoperative morbidity and mortality, and decreased incidence of cognitive dysfunction. In spine surgery, RA is associated with lower pain scores, postoperative nausea and vomiting, positioning injuries, shorter anesthesia time, and higher patient satisfaction. Currently, RA is mostly used in short lumbar spine surgeries. However, recent findings illustrate the possibility of applying RA in spinal tumors and spinal fusion. Various researches reveal that SA is an effective alternative to GA with lower minor complications incidence. Comprehensive insight on RA will promote spine surgery under RA, thereby broadening the horizon of spine surgery under RA.

Neuro-anesthesiology in pregnancy

Management of the pregnant patient requiring neurosurgery poses multiple challenges, juxtaposing pregnancy-specific considerations with that accompanying the safe provision of intracranial or spine surgery. There are no specific evidence-based recommendations, and case-by-case interdisciplinary discussions will guide informed decision-making about the timing of delivery vis-à-vis neurosurgery, the performance of cesarean delivery immediately before neurosurgery, consequences of neurosurgery on subsequent delivery, or even the optimal anesthetic modality for neurosurgery and/or cesarean delivery. In general, identifying whether increased intracranial pressure poses a risk for herniation is crucial before allowing neuraxial procedures. Modified rapid sequence induction with advanced airway approaches (videolaryngoscopic or fiberoptic) allows improved airway manipulation with reduced risks associated with endotracheal intubation of the obstetric airway. Currently, very few anesthetic drugs are avoided in the neurosurgical pregnant patient; however, ensuring access to critical care units for prolonged monitoring and assistance of the respiratory-compromised patient is necessary to ensure safe outcomes.

Focal Neurologic Deficit After Epidural Catheter Removal Leads to Meningioma Diagnosis

We present an unusual case of a 60-year-old female who developed subtle, new-onset left upper and lower extremity weakness on day five of perioperative thoracic epidural placement. The onset of a focal neurological deficit after epidural placement usually raises suspicion for the presence of an epidural hematoma, abscess, or traumatic cord lesion. However, in this patient, brain imaging revealed a large, previously undiagnosed intracranial mass. Classically, the risk of mass-related intracranial pressure shifts leading to neurological changes is associated with spinal techniques, including diagnostic lumbar puncture, combined spinal-epidural catheter analgesia, and unintended dural puncture during epidural placement. However, based on this case and our summary of case reports in the literature, we determined that symptom onset associated with an intracranial mass may also arise after apparently uncomplicated epidural placement. Symptom onset in our case series ranged from six hours to ten days and was highly variable depending on tumor location, with reported signs and symptoms including headache, vision changes, focal deficits, or alterations of consciousness. Further studies are required to establish definitive causation between the epidural technique and changes in cerebrospinal fluid pressures leading to symptom onset. Though rare, this is a time-sensitive diagnosis that must be considered for any patient with unexplained neurological findings after neuraxial anesthesia.

The Effects of the Amount of Fluid Used in Epiduroscopic Laser Neural Discectomy Procedures on Intraocular Pressure and an Evaluation of the Ocular Findings

INTRODUCTION

During epiduroscopic laser neural discectomy (ELNP) procedures, the amount of fluid used in the epidural area may cause increased intracranial pressure. This study aimed to investigate the effect of increased epidural pressure on intraocular pressure and other ocular findings due to the amount of fluid delivered to the epidural area and the rate of delivery of the fluid.

MATERIAL AND METHODS

After obtaining approval from the Ethics Committee of Sakarya University Faculty of Medicine, patients who underwent ELNP in the Department of Anesthesiology and Reanimation Department, Algology Clinic, between January 2017 and May 2017 were included in this retrospective study. To evaluate the ocular findings after the operation, measurements obtained using an optical coherence tomography device were retrieved from the patient files and evaluated.

RESULTS

Data from the medical files of 52 patients from the hospital system were evaluated. There was no significant difference between preoperative and postoperative retinal nerve fiber layer (RNFL) thickness, mean central macular thickness, optic disk area, and vertical cup-to-disk ratio (P > 0.05).

CONCLUSIONS

Epiduroscopy procedures include intermittent or continuous infusion of saline into the epidural area. Currently, the volume of fluid that should be given to the epidural area in epiduroscopy procedures is very controversial. As a result of this study, we concluded that the amount of fluid used during ELNP, at 107.25 mL and 8.33 mL/min, had no effect on the intraocular pressure, optic disk diameter, macular thickness, or peripapillary RNFL thickness; thus, it was safe for ELNP.

Assessing changes in cervical epidural pressure during biportal endoscopic lumbar discectomy

OBJECTIVE

Biportal endoscopic spinal surgery has been performed for several years, and its effectiveness is well known; however, no studies on its safety, specifically intracranial pressure, have been conducted to date. The authors sought to evaluate the effect of biportal endoscopic lumbar discectomy on intracranial pressure by monitoring cervical epidural pressure (CEP) changes throughout the procedure.

METHODS

Twenty patients undergoing single-level biportal endoscopic lumbar discectomy were enrolled in this study. CEPs were monitored throughout the procedure, consisting of phase 1, establishing the surgical portal and working space; phase 2, performing decompression and discectomy; and phase 3, turning off the fluid irrigation system. After discectomy was completed, the authors evaluated changes in CEP as the irrigation pressure increased serially by adding phase 4, increasing irrigation pressure with outflow open; and phase 5, increasing irrigation pressure with outflow closed.

RESULTS

The mean baseline CEP was measured as 16.65 mm Hg. In phase 1, the mean CEP was 17.3 mm Hg, which was not significantly different from the baseline CEP. In phase 2, the mean CEP abruptly increased up to 35.1 mm Hg when the epidural space was first connected with the working space, followed by stabilization of the CEP at 31.65 mm Hg. In phase 4, the CEP increased as the inflow pressure increased, showing a linear correlation, but not in phase 5. No patients experienced neurological complications.

CONCLUSIONS

It is important to ensure that irrigation fluid is not stagnant and is maintained continuously. More attention must be paid to keeping pressures low when opening the epidural space.

Effect of phentolamine mesylate on regression of lidocaine-epinephrine epidural anaesthesia in sheep

OBJECTIVE

To determine the impact of epidural phentolamine on the duration of anaesthesia following epidural injection of lidocaine-epinephrine.

STUDY DESIGN

Blinded randomized experimental study.

ANIMALS

A group of 12 adult ewes weighing 25.7 ± 2.3 kg and aged 8-9 months.

METHODS

All sheep were administered epidural lidocaine (approximately 4 mg kg^-1) and epinephrine (5 μg mL^-1). Of these, six sheep were randomized into three epidural treatments, separated by 1 week, administered 30 minutes after lidocaine-epinephrine: SAL: normal saline, PHE1: phentolamine (1 mg) and PHE2: phentolamine (2 mg). The other six sheep were administered only epidural lidocaine-epinephrine: treatment LIDEP. Each injection was corrected to 5 mL using 0.9% saline. Noxious stimuli were pinpricks with a hypodermic needle and skin pinch with haemostatic forceps to determine the onset and duration of sensory and motor block. Heart rate, noninvasive mean arterial pressure (MAP), respiratory rate and rectal temperature were recorded.

RESULTS

The onset times were not different among treatments. Duration of sensory block was significantly shorter in SAL (57.5 ± 6.2 minutes), PHE1 (60.7 ± 9.0 minutes) and PHE2 (62.0 ± 6.7 minutes) than in LIDEP (81.7 ± 13.4 minutes) (p < 0.05). Duration of motor blockade was significantly shorter in PHE1 (59.4 ± 5.4 minutes) and PHE2 (54.3 ± 4.0 minutes) than in SAL (84.8 ± 7.0 minutes) and LIDEP (91.5 ± 18.2 minutes) (p < 0.01). MAP in PHE2 was decreased at 10 minutes after administration of phentolamine (p < 0.05).

CONCLUSION AND CLINICAL RELEVANCE

Epidural administration of 5 mL normal saline after epidural injection of lidocaine-epinephrine reduced the duration of sensory but not motor block in sheep. Epidural administration of phentolamine diluted to the final volume of 5 mL diminished both the duration of sensory and motor block in sheep administered epidural lidocaine-epinephrine.

Epidural Anesthesia for Cesarean Delivery in a Parturient With Lumboperitoneal Shunt: A Case Report

A lumboperitoneal shunt facilitates dynamic flow of cerebrospinal fluid into the peritoneum. Consequently, neuraxial technique placement in the parturient with a lumboperitoneal shunt can result in unexpected levels of blockade. We present the case of a parturient with a lumboperitoneal shunt who experienced symptoms consistent with high blockade after epidural administration of 450 mg chloroprocaine. This report emphasizes potential mechanisms for high neuraxial blockade and strategies to decrease risks in this unique patient population.

Anesthetic considerations for extracranial injuries in patients with associated brain trauma

Patients with severe traumatic brain injury often presents with extracranial injuries, which may contribute to fatal outcome. Anesthetic management of such polytrauma patients is extremely challenging that includes prioritizing the organ system to be dealt first, reducing on-going injury, and preventing secondary injuries. Neuroprotective and neurorescue measures should be instituted simultaneously during extracranial surgeries. Selection of anesthetic drugs that minimally interferes with cerebral dynamics, maintenance of hemodynamics and cerebral perfusion pressure, optimal utilization of multimodal monitoring techniques, and aggressive rehabilitation approach are the key factors for improving overall patient outcome.

Spinal anesthesia performed for cesarean delivery after external ventricular drain placement in a parturient with symptomatology from an intracranial mass

We describe a case in which spinal anesthesia was undertaken in a pregnant patient with a space-occupying tumor and significant symptomatology. The collaborative efforts of all medical disciplines involved and the willingness of the neurosurgeon to discuss and help determine the safety of neuraxial anesthesia, culminated in placing an external ventricular drain to help monitor and manage intracranial pressure, so that we could proceed with spinal anesthesia and more easily monitor neurologic status.

Spinal neuraxial anaesthesia for caesarean section in a parturient with type I Arnold Chiari malformation and syringomyelia

Introduction

Type 1 Arnold Chiari malformation is associated with prolapse of the cerebellar tonsils into or below the level of the foramen magnum and is usually diagnosed in adults. There are no current guidelines for the management of patients with a residual type I Arnold Chiari malformation, planned for a caesarean section under spinal neuraxial anaesthesia. The paucity in the literature on this topic presents as a management dilemma.

Case report

We report a case of a term parturient with type 1 Arnold Chiari malformation, following surgical decompression 4 years earlier, with a residual syringomyelia that underwent an elective caesarean section under spinal neuraxial anaesthesia.

Conclusion

This case highlights that multidisciplinary management and early anaesthetic consult are of paramount importance in the outcome of the patient, and that spinal neuraxial anaesthesia can be considered as a safe anaesthetic option.

Management of parturients in active labor with Arnold Chiari malformation, tonsillar herniation, and syringomyelia

BACKGROUND

Arnold-Chiari malformation Type 1 (ACM-1) in parturients is a topic of ongoing discussion between obstetricians and anesthesiologists. The primary unanswered question remains; How should the anesthesia provider proceed with labor analgesia and anesthesia for cesarean section when confronted with an advanced, asymptomatic, or minimally symptomatic case of ACM-1 during labor?

CASE DESCRIPTION

A 24-year-old, ASA II, G1P0 full-term parturient presented to Labor and Delivery for vaginal delivery. A diagnosis of ACM-1 was made 12 years ago when a brain magnetic resonance imaging (MRI) was performed for right-sided numbness following a rear-end motor vehicle collision. The patient had been asymptomatic since then and had been seen by an outside neurologist frequently for the past 10 years. During the anesthesia evaluation, it was noted that she had an exaggerated patellar reflex, and a questionable left-sided Babinski; subsequently, an MRI study was requested. Review of a brain MRI demonstrated an advanced form of ACM with a 1.7 cm transtonsillar herniation and a large syrinx extending from C1 down to C5. Following a discussion with the patient, family, and primary OB team, a plan for elective cesarean section was made per neurosurgical recommendations. This was conducted uneventfully under general anesthesia. The patient had no complaints in the post-anesthesia care unit.

CONCLUSION

Unfamiliarity of health care providers with regards to ACM-1 parturients can be countered by increasing awareness of this condition throughout medical specialties involved in their care. The Ghaly Obstetric Guide to Arnold-Chiari malformation Type 1, along with proper training of anesthesia care providers regarding the specificities of ACM-1 parturients aids in better management and understanding of this complex condition.

Use of an Intrathecal Catheter for Analgesia, Anesthesia, and Therapy in an Obstetric Patient with Pseudotumor Cerebri Syndrome

Pseudotumor cerebri syndrome (PTCS) is a rare disorder chiefly observed in obese women of childbearing age. We describe a case of a parturient with PTCS managed successfully with an intrathecal catheter, after inadvertent dural puncture, for labor analgesia, surgical anesthesia, and treatment of headache because of intracranial hypertension during the peripartum period. Prolonged placement of the intrathecal catheter (i.e., >24 hours) may have contributed to the absence of postdural puncture headache symptoms and an uneventful postpartum period. Intrathecal catheter placement may therefore be a viable option in patients with PTCS should inadvertent dural puncture occur.

Safety and efficacy of combined epidural/general anesthesia during major abdominal surgery in patients with increased intracranial pressure: a cohort study

Background

The increased intracranial pressure can significantly complicate the perioperative period in major abdominal surgery, increasing the risk of complications, the length of recovery from the surgery, worsening the outcome. Epidural anesthesia has become a routine component of abdominal surgery, but its use in patients with increased intracranial pressure remains controversial. The goal of the study was to evaluate the safety and efficacy of epidural anesthesia, according to monitoring of intracranial pressure in patients with increased intracranial pressure.

Methods

The study includes 65 surgical patients who were routinely undergone the major abdominal surgery under combined epidural/general anesthesia. Depending on the initial ICP all patients were divided into 2 groups: 1 (N group) - patients with the normal intracranial pressure (≤12 mm Hg, n = 35) and 2 (E group) – patients with the elevated intracranial pressure (ICP > 12 mm Hg, n = 30). During the surgery we evaluated ICP, blood pressure, cerebral perfusion pressure (CPP). The parameters of recovery from anesthesia and the effectiveness of postoperative analgesia were also assessed.

Results

In N group ICP remained stable. In E group ICP decreased during anesthesia, the overall decline was 40 % at the end of the operation (from 15 to 9 mm Hg (P <0.05)). The correction of MAP with vasopressors to maintain normal CPP was required mainly in patients with increased ICP (70 % vs. 45 %, p <0.05). CPP declined by 19 % in N group. In E group the CPP reduction was 23 %, and then it remained stable at 60 mm Hg. No significant differences in time of the recovery of consciousness, effectiveness of postoperative analgesia and complications between patients with initially normal levels of ICP and patients with ICH were noted.

Conclusions

The combination of general and epidural anesthesia is safe and effective in patients with increased intracranial pressure undergoing elective abdominal surgery under the condition of maintaining the arterial pressure. Its use is not associated with the increase in intracranial pressure during the anesthesia, but it needs an intraoperative monitoring of ICP in order to prevent CPP reduction.

Anesthetic management of labor and delivery in patients with elevated intracranial pressure

The anesthetic management of labor and delivery in patients with elevated intracranial pressure is complex. This review discusses the etiologies of diffuse and focal pathologies which lead to elevated intracranial pressure in pregnancy. The role of neuraxial and general anesthesia in the management of labor and delivery is also examined. Finally, a comprehensive review of strategies to minimize increases in intracranial pressure during general anesthesia for cesarean delivery is presented.

Epidural anesthesia for caesarean section in a pregnant patient with pituitary macroadenoma

Anaesthesia for patient with pituitary adenoma posted for non-neurosurgical surgeries is a challenge to the anaesthesiologist with the risk of sudden change in intracranial dynamics during administration of spinal anaesthesia or during stress response of general anaesthesia. There is a chance of increase in tumour size during antenatal period. A careful assessment of pituitary function and a screening of visual field and fundus examination are essential to rule out any mass effect. We are presenting the anaesthetic management of patient with pituitary macroadenoma posted for elective caesarean section done under epidural anaesthesia due to its rarity.

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

BACKGROUND

During an epidural blood patch, we inject blood until the patient describes mild back pressure, often leading to injection of more than 20 mL of blood. We undertook this study to measure the epidural pressures generated during an epidural blood patch and to identify the impact of volume on epidural elastance in obstetric patients.

METHODS

This study was performed in postpartum patients who presented for an epidural blood patch with symptoms consistent with a postdural puncture headache. After identification of the epidural space using loss of resistance to air or saline, we measured static epidural pressure after each 5-mL injection of blood. Models were then fitted to the data and the epidural elastance and compliance calculated.

RESULTS

Eighteen blood patches were performed on 17 patients. The mean final volume injected was 18.9±7.8 mL [range 6-38 mL]. The mean final pressure generated was 13.1±13.4 mmHg [range 2-56 mmHg]. A curvilinear relationship existed between volume injected and pressure, which was described by two models: (1) pressure=0.0254×(mL injected)(2)+0.0297 mL, or (2) pressure=0.0679×mL(1.742). The value for r2 was approximately 0.57 for both models. We found no correlation between the final pressure generated and the success of the epidural blood patch.

CONCLUSIONS

We found a curvilinear relationship between the volume of blood injected during an epidural blood patch and the pressure generated in the epidural space. However, there was a large variation in both the volume of blood and the epidural pressure generated. The clinical importance of this finding is not known. A larger study would be required to demonstrate whether pressure is a predictor of success.

[Idiopathic intracranial hypertension: a caesarean with epidural anaesthesia after bringing the cerebrospinal fluid pressure back to normal]

Idiopathic intracranial hypertension is diagnosed by exclusion. Because of its uncertain physiopathology and infrequent occurrence, its anaesthetic management is not well defined. The patient in this case is a pregnant woman with this disease with no lumbar-peritoneal shunt who was referred for non-urgent caesarean section, consisting of CSF drainage and pressure normalisation before the administration of epidural anaesthesia. We believe this technique can de effective to achieve adequate blockage and increased patient comfort, as well as improving postoperative recovery.

Neuraxial Anesthesia in Parturients with Intracranial Pathology

Parturients with intracranial lesions are often assumed to have increased intracranial pressure, even in the absence of clinical and radiographic signs. The risk of herniation after an inadvertent dural puncture is frequently cited as a contraindication to neuraxial anesthesia. This article reviews the relevant literature on the use of neuraxial anesthesia in parturients with known intracranial pathology, and proposes a framework and recommendations for assessing risk of neurologic deterioration, with epidural analgesia or anesthesia, or planned or inadvertent dural puncture. The authors illustrate these concepts with numerous case examples and provide guidance for the practicing anesthesiologist in determining the safety of neuraxial anesthesia.

Occurrence of trochlear nerve palsy after epiduroscopic laser discectomy and neural decompression

Epiduroscopic laser discectomy and neural decompression (ELND) is known as an effective treatment for intractable lumbar pain and radiating pain which develop after lumbar surgery, as well as for herniation of the intervertebral disk and spinal stenosis. However, various complications occur due to the invasiveness of this procedure and epidural adhesion, and rarely, cranial nerve damage can occur due to increased intracranial pressure. Here, the authors report case in which double vision occurred after epiduroscopic laser discectomy and neural decompression in a patient with failed back surgery syndrome (FBSS).

Magnetic resonance imaging is essential prior to spinal subarachnoid blockade for parturients with a history of brain tumor resection undergoing cesarean section

BACKGROUND

Primary brain tumors are usually treated by surgical removal with the goal of complete resection within the constraints of preservation of neurological function. However, gross total resection may not mean complete tumor removal, and ongoing compression from a mass effect can lead to serious sequelae. Spinal subarachnoid blockade is contraindicated in patients with brain tumors or space occupying lesions.

CASE DESCRIPTION

A 32-year-old full term parturient presented to Labor and Delivery for semi-urgent repeat cesarean section. Three months ago, she underwent resection of a benign brain tumor and recovered with no new neurological deficits. The neurosurgeon was consulted by the anesthesia team and stated that the tumor was completely extirpated. Since there was no postoperative magnetic resonance imaging (MRI) and the patient still had some neurological deficits, the anesthesia team decided to proceed with a general anesthetic using a rapid sequence induction and intubation. Mild hyperventilation to maintain an end-tidal CO(2) of 30 mmHg was selected and conservative fluid management was maintained. Postcesarean MRI revealed residual tumor compressing the brain stem and a loculated cyst. If a spinal subarachnoid blockade technique had been selected, the risk of uncal herniation, based on the postoperative MRI findings, may have been realized.

CONCLUSIONS

The present case demonstrates the necessity of a comprehensive and thorough review prior to selecting the anesthetic approach to mange the patients with a history of brain tumor resection. Postoperative MR imaging should be performed to evaluate the extent of tumor resection and possible existence of residual tumor.

Psoas compartment block for operative reduction of hip fracture in a patient with increased intracranial pressure due to inoperable brain tumor

General and neuraxial anesthesia in patients with increased intracranial pressure (ICP) who present for non-neurosurgical surgery may cause life-threatening changes in ICP, with possible fatal outcome. Peripheral nerve blocks may be a safe alternative technique for limb surgery. The successful use of psoas compartment block for operative reduction of a hip fracture in a patient with increased ICP due to an inoperable brain tumor is presented.

Epidural anesthesia for Cesarean delivery in a patient with post-traumatic cervical syringomyelia

PURPOSE

To illustrate the successful management of a patient with post-traumatic syringomyelia (PTS) and chronic pain syndrome who presented for elective Cesarean delivery under epidural anesthesia.

CLINICAL FINDINGS

A 30-yr-old gravida 3 para 1 woman, with a known diagnosis of cervical PTS secondary to a whiplash injury sustained three years earlier, presented to the labour and delivery unit at 31 weeks' gestation. She had severe pain in the cervical and lumbar spine, motor and sensory deficits in the upper extremities, tender mass in her left trapezius muscle, and history of dizziness and syncopal episodes. She was taking oxycodone 120 mg·day(-1) Magnetic resonance imaging of her spine revealed a syrinx of 2 mm in diameter extending from C4 to T1 levels with disc protrusions in the C4-C6 region. There was no evidence of Arnold-Chiari malformation or elevated intracranial pressure. On airway examination, her Mallampati score appeared normal, but there was a limitation in the range of her neck movements in all directions. An elective Cesarean delivery was planned at 39 weeks' gestation. An epidural catheter was placed using ultrasound guidance, and the procedure was performed without complications.

CONCLUSIONS

The successful management of this case suggests that epidural can be considered in women with cervical PTS presenting for a Cesarean delivery.

[Regional anesthesia and neurological diseases]

Modern anesthesia is handling an increasing number of patients with neurological diseases who require narcosis. Regional anesthesia techniques offer qualities which might be advantageous for this group particularly for childbirth. The number of pregnant women with neurological diseases has increased significantly in the recent years due to improved diagnostics and therapy. A more careful approach to regional anesthesia in patients with neurological diseases is necessary as the drugs themselves possess neurotoxic effects and the procedure might worsen the underlying neurological diseases. Additionally, performing regional anesthesia might be more complicated and the resulting blockade might be different from the expected neuronal block. Published data concerning regional anesthesia in this patient group are limited and mainly restricted to case reports. In this review general considerations regarding regional anesthesia, techniques, drugs and methods in these patient groups will be discussed. In the second part the practical approach to regional anesthesia for some of the most important neurological diseases is highlighted.

Intracranial arachnoid cysts and obstetric anesthesia: two case reports

Two cases of patients in whom neuraxial anesthesia was planned for labor and delivery and who had a pre-existing intracranial arachnoid cyst are reported. Anesthesia was used in one patient and was uneventful. The pathophysiology of these cysts and factors which can precipitate the occurrence of symptoms, are reviewed and cases previously described in the literature are examined. Management should be individualized and based on evaluation of preexisting neurological symptoms. In most cases and although CT scan and MRI images may show an intracranial cyst with impressive development, patients remain asymptomatic and neuraxial regional anesthesia can be used safely, provided the patient has agreed and the neurologist in charge has been informed.

Anaesthesia for the obstetric patient with (non-obstetric) systemic disease

The number of women with serious (non-obstetric) systemic diseases achieving pregnancy and requiring obstetric anaesthetic management is increasing. The conditions that are most likely to cause maternal morbidity and mortality are cardiac disease, respiratory disease, neuromuscular disease, haematological disease, connective and metabolic diseases and psychiatric conditions including substance abuse. This article discusses the anaesthetic management of the pregnant mother with such serious systemic diseases.

Comparative study of neck pain in relation to increase of cervical epidural pressure during percutaneous endoscopic lumbar discectomy

STUDY DESIGN

A prospective study.

OBJECTIVE

By monitoring cervical epidural pressure (EP) changes throughout the procedure, we intend to discover the effect of percutaneous endoscopic lumbar discectomy (PELD) on cervical epidural pressure and whether there is a correlation between posterior neck pain and increased cervical EP, which is known to have a linear correlation with intracranial pressure (ICP).

SUMMARY OF BACKGROUND DATA

Patients sometimes complain of posterior neck pain during PELD. Due to the massive irrigation fluid used during the procedure, the possibility of increased ICP as the cause is quite strong.

METHODS

Twenty-eight patients undergoing PELD with ASA physical status 1 or 2 were enrolled in this study. In all patients, a cervical epidural catheter was placed at the C6-C7 level before the procedure and was connected to a pressure transducer. Cervical EPs were monitored continuously throughout the procedure. Initial stabilized EP (EP), EP at the time of neck pain, maximal EP during the procedure, and EP at the end of the procedure were checked. Neck pain onset time from the beginning of irrigation and total irrigation time were also checked.

RESULTS

Of 28 patients, 8 patients complained of neck pain. Neck pain onset time from the beginning of irrigation was 35.6 +/- 11.3 (mean +/- SD) minutes. The EP at the time of neck pain (52.9 +/- 9.2 mm Hg) was significantly higher than the maximal EP in patients without neck pain (34.8 +/- 14.7 mm Hg). In all patients who complained of neck pain, the cervical EP at the time of neck pain showed pressures above 37 mm Hg. The maximal EP in those with neck pain (73.6 +/- 25.8 mm Hg) was also significantly higher than the EP in those without neck pain (34.8 +/- 14.7 mm Hg). In a correlation study, patients with higher maximal EPs had higher probabilities of having neck pain. In 6 of 8 patients, an abrupt increase in EP was observed after the onset of neck pain, while in the other 2 patients, the procedure ended just after neck pain appeared.

CONCLUSION

Neck pain occurring during PELD is associated with a highly increased cervical EP generated by continuous infusion.

Anaesthetic considerations for patients with a pre-existing neurological deficit: are neuraxial techniques safe?

Pre-existing neurological and muscular disease may be a specific concern for anaesthetists as they need to consider the effect of anaesthesia upon the disease, vice versa, and the interaction of anaesthesia with the medication taken by the patient. Despite a lack of controlled studies, many anaesthetists, being afraid of a claim, will prefer general rather than regional anaesthesia in these patients. Nevertheless regional anaesthesia certainly merits its place because it offers undeniable advantages. A good pre-operative examination is very important while patients should also be informed about peri-operative implications of anaesthesia, surgery and stress. Paraesthesias, epinephrine and high concentrations of local anaesthetics should be avoided in the majority of the diseases. Some diseases may benefit from epidural anaesthesia while for others a spinal technique may be the technique of preference. Special attention should be paid to patients with spinal stenosis despite recent reassuring reports with respect to safety of regional anaesthetic techniques. Anaesthetists should not automatically take all responsibility in case of progressive or new deficit after the procedure.

Post-delivery postural headache: not always a classical post-dural puncture headache

We report a parturient complaining of headache after spinal and epidural labour analgesia with neurological deterioration following an epidural blood patch. Further investigation revealed a medulloblastoma within the fourth ventricle. The patient underwent an operation 4 days after the diagnosis, but died 2 years later. The consequences of the use of neuraxial analgesia and epidural blood patch in the treatment of post-dural puncture headache in this kind of pathology are discussed.

Intracranial arachnoid cyst: anaesthetic management in pregnancy

Arachnoid cysts may be intracranial or extracranial in the neuraxis and may present with headache and neurological signs or acutely with rupture and its complications. We report a case of spinal anaesthesia for elective caesarean section in a woman with an intracranial arachnoid cyst of the posterior fossa. We are unaware of any other such case reports published in the English language.

An unusual intracranial tumour presenting in pregnancy

We describe a patient who presented in late pregnancy with deteriorating neurological status due to an intracranial capillary haemangioma causing mass effect and raised intracranial pressure. She became confused and uncooperative leading to practical difficulties in performing adequate radiological imaging. Decision regarding timing of delivery and craniotomy was not straightforward and required discussion between the neurosurgeon, obstetrician and anaesthetist based on assessment of fetal maturity and the need to perform a craniotomy to excise what was initially thought to be a meningioma. Caesarean section was performed under general anaesthesia. The tumour was resected three weeks later. Management of obstetric patients with brain tumours is complex, requiring knowledge of the physiological effects of pregnancy on tumour size and labour on intracranial pressure. Both of these may influence the choice of labour analgesia or anaesthesia for caesarean section. Anaesthetists must be aware of the difficulties of radiological imaging during pregnancy, particularly in confused patients. The conflicting requirements of general anaesthesia for craniotomy and caesarean section should be considered.

Visual Impairment Following Epidural Fluid Injections and Epiduroscopy: A Review

INTRODUCTION

Visual impairment apparently is a rare but significant complication following epidural fluid injection and epiduroscopy. We report a review of cases reported in the literature with the aim of gaining an understanding of how the complication occurs as well as how to avoid it.

MATERIALS AND METHODS

A literature review was performed using PubMed to find 1) case reports and 2) factors that contribute to the development of visual loss in the cases.

RESULTS

Twelve cases of visual impairment following epiduroscopy or epidural fluid injection have been reported in the literature. The average age of the patients was approximately 50 years, 83.3% of the patients were female, 16.7% were male. Bolus injection of fluid with or without epiduroscopy was considered to be the precipitating event. The volume of solution injected epidurally varied from 20 mL to 120 mL (average = 59.4 mL). The common finding was retinal hemorrhage, with 58.3% occurring bilaterally. Recovery occurred in 79.2% of the cases.

CONCLUSION

Retinal hemorrhage following epidural fluid injections/epiduroscopy apparently is due to an increase in cerebrospinal fluid pressure proportional to the rate and the amount of fluid injected. A sudden increase in epidural pressure is transmitted into the subarachnoid space to the optic nerve sheath, compressing the optic nerve and its vasculature. The vasculature compression ruptures retinal blood vessels.

Arnold-Chiari malformation and pregnancy

Chiari (or Arnold-Chiari) malformations are a continuum of abnormalities of the hindbrain with the possibility of disordered cerebrospinal fluid flow and craniospinal pressure gradients. We describe the management of a 30-year-old primigravida who presented following a grand mal seizure during the first trimester. A Chiari type I malformation was diagnosed radiologically. She was delivered at term by elective caesarean section using a general anaesthetic technique. The difficulties in anaesthetising the patient with Chiari malformation are considered, and a literature review is presented to illustrate the risk-benefit analysis undertaken.

Epidural analgesia associated with a fatal outcome in a patient with an unrecognized brain tumour

A fatality associated with epidural analgesia in a patient with an unsuspected brain tumour has not been reported in the literature. We describe a case of postoperative lumbar epidural analgesia in a 54-year-old female patient who had an undiagnosed brain tumour and a fatal outcome postoperatively. The factors that potentially contributed to this mishap and the possible alternative management of this patient are discussed.