Anesthetic management of a patient with a huge ovarian tumor

We managed a patient with a huge ovarian tumor (15 kg). The patient was a 50-year-old woman and could not take the supine position because of the tumor causing respiratory embarrassment. An epidural catheter was inserted 3 cm cephalad via the Th 11-12 interspace in the right lateral position. Three milliliters of 1% mepivacaine was injected epidurally for test dose and produced hypesthesia of Th 9-12 five min after the injection. Additional 3 ml of 1% mepivacaine was injected epidurally, which widened the hypesthesia to Th 5-L 2. Intra-arterial pressure was monitored continuously. Under epidural anesthesia without sedation, 11,000 ml of fluid was suctioned slowly from the cyst in 20 min, during which time remarkable hemodynamic derangement did not occur. The patient was turned into the supine position and the trachea was intubated. Laparotomy was performed under general anesthesia. During the surgery, respiratory and hemodynamic conditions were stable. On the following day, chest radiography demonstrated an abnormal shadow in the lower lobe of the right lung. It disappeared the next day without any treatment. Anesthetic management of patients with huge abdominal tumor is also discussed.     

The epidural structure changes during deep breathing

PURPOSE: Previous experience has suggested that the insertion of an epidural catheter becomes easier when the patient takes a deep breath. The purpose of this study is to investigate the effects of respiration on the epidural space. METHODS: We examined the epidural space using a flexible epiduroscope in 20 patients undergoing thoracic epidural anesthesia. A 17-gauge Tuohy needle was inserted using the paramedian technique and the loss-of-resistance method with 5 ml air. The epiduroscope was introduced into the epidural space via the Tuohy needle. Each patient was requested to take a deep breath when the epiduroscope was positioned at the needle tip and at approximately 10 cm cephalad from the needle tip within the epidural space. The changes in the epidural structure during deep breathing at each site were then measured. RESULTS: In 80% of the patients, fatty tissue occupied the needle tip. Through the patients' maximal inspiration, the fatty tissue moved and a visible cavity expanded at the needle tip. Cross section area of the visible cavity at the needle tip was greater at the maximal inspiratory level than at the resting expiratory level: 12.1 +/- 6.7% vs 2.8 +/- 2.1% (mean +/- SD, P < 0.0001). In all patients, the visible cavity within the epidural space, which had already been expanded by injected air, became more expanded after maximal inspiration. Cross section area of the visible cavity at the 10 cm cephalad position was greater at the maximal inspiratory level than at the resting expiratory level: 20.6 +/- 10.0% vs 7.0 +/- 5.3% (P < 0.0001). CONCLUSION: Epiduroscopy showed that deep breathing expanded the potential cavity of the epidural space. We suggest that the changes in the epidural structure during deep breathing may assist in the insertion of an epidural catheter.     

Saline — anesthetic interval and the spread of epidural anesthesia

PURPOSE: To examine the effect of modifying the interval between administration of saline used during the loss of resistance (LOR) method and local anesthetic on epidural anesthetic level and its quality. METHODS: Seventy-three patients who received thoracic epidural anesthesia were randomly allocated into three groups; the 2, 5 and 10 min groups, according to the interval between the administration of saline and 8 ml mepivacaine 1.5%. Fifteen minutes after the mepivacaine injection, the dermatome level of hypesthesia was determined by an individual blinded to the interval. RESULTS: When the saline-anesthetic interval was prolonged, the hypesthetic levels for coldness and pinprick were decreased. The number of spinal segments with hypesthesia for coldness were 15 [12-20]#, 12.5 [10.5-22.5]## and 10.5 [6.5-15.5]### in the 2, 5 and 10 min groups, respectively (median [range], # P < 0.05 vs the 5 min group, ## P < 0.05 vs the 10 min group, ### P < 0.05 vs the 2 min group). The number of spinal segments with hypesthesia for pinprick were 13.5 [11-18]#, 11 [7.5-20.5]## and 10 [5.5-13]### in the 2, 5 and 10 min groups, respectively. There were differences in all groups between the number of segments with hypesthesia for coldness and pinprick elicited. CONCLUSION: The interval between the administration of saline and local anesthetic alters the anesthetic level and quality of epidural analgesia.     

Thoracic epidural catheter insertion using the caudal approach assisted with an electrical nerve stimulator in young children

OBJECTIVES: We evaluated whether thoracic epidural catheter placement using the caudal approach and assisted with an electrical stimulator could be performed in young children. METHODS: Ten young children (1-4 years) who underwent abdominal surgeries were studied. Under general anesthesia without muscle relaxants, caudal catheter placement was performed using an 18-gauge Crawford-type needle and a 20-gauge radiopaque epidural catheter with a stainless-steel stylet. A metal adapter and a 3-way stopcock were attached to the catheter to connect to an electrical stimulator and to inject physiological saline. Electrical stimulation was performed intermittently while advancing the catheter until it reached the target length. The catheter position was confirmed on postoperative roentgenogram. RESULTS: The mean age of the subjects was 32.2 +/- 10.1 months (13-48 months), and the height was 85.3 +/- 6.1 cm (72-93 cm). In 9 of 10 patients, an epidural catheter could be placed at the first insertion. In 1 patient, the catheter could be placed successfully at the second insertion. The electrical current required for muscle contraction at the target length was 5.8 +/- 1.5 mA. CONCLUSION: Electrical stimulation reliably indicated the location of the catheter tip. This technique for thoracic epidural catheter insertion was easy to perform and could be used in young children.     

Spinal epidural hematoma following removal of incorrectly placed jugular central venous catheter

The authors report a rare case of iatrogenic spinal epidural hematoma associated with central venous catheter cannulation via the right internal jugular vein. This 59-year-old man was operated on for stomach cancer while under general anesthesia. A central venous line was inserted via the right internal jugular vein. The operation was completed uneventfully and postoperative fluid replacement was continued without interruption. On postoperative Day 2, marked swelling around the right side of his neck gradually worsened. Cervical CT demonstrated that the catheter tip of the central venous line had penetrated the jugular vein and entered the intervertebral foramen (C5-6), thereby reaching the spinal epidural space. The patient was immediately transported to the operating room and the catheter was carefully extracted under fluoroscopy. Several minutes after catheter removal, the patient complained of sudden severe back pain and over time developed mild paraparesis of both lower extremities. Urgent MR imaging of the spine revealed a large spinal epidural hematoma extending from C-1 to T-8 that was compressing the dorsal spinal cord. The patient underwent emergency surgical removal of the epidural hematoma as well as spinal cord decompression with a T1-4 laminectomy. After surgery, the patient showed full recovery of his lower-extremity motor function.     

A case of epidural hematoma associated with epidural catheterization which occurred on 12th days after the last medication of ticlopidine hydrochloride

A 72-year-old woman underwent choledocholithotomy under general anesthesia combined with epidural block. She was complicated with hypertension, diabetes mellitus and angina pectoris, and was given ticlopidine hydrochloride. The medication was stopped 12 days before the operation. Her coagulation tests and platelet counts were within normal ranges. An epidural catheter was inserted at Th 9-10 interspace, and continuous epidural anesthesia was started for postoperative pain. Just after the operation, numbness and motor paralysis in both legs occurred. We stopped continuous epidural anesthesia, and the symptom on right leg improved. However, after 2 days, magnetic resonance imaging revealed epidural hematoma extending from Th7 to L1, and the patient underwent laminectomy. After a month, her motor paralysis in the left leg started to improve gradually. It is possible that the term of discontinuation of ticlopidine was not enough. We should stop antiplatelet drugs early enough, and should be aware of early symptoms of spinal cord compression.     

Thoracic epidural anesthesia via the caudal approach in children.

We investigated the feasibility of performing thoracic epidural anesthesia via the caudal approach in 20 children (age 62 +/- 38 months and weight 18.5 +/- 7.3 kg; mean +/- standard deviation). Based on external landmarks, a predetermined length of 24-G epidural catheter (Concord Portex 20/24 microcatheter system) with stylet was passed into the epidural space through a 20-G intravenous catheter inserted through the sacrococcygeal ligament, and a radiograph of the abdomen and chest was obtained. The radiographically determined catheter tip position was within two vertebrae of the target position in 17 of 20 subjects. In one subject, it was impossible to advance the catheter more than 10 cm. The other two malpositioned catheters were successfully reinserted. Intraoperative caudal anesthesia and postoperative pain relief were satisfactory in all 20 subjects. We have found it possible to use the caudal approach to thoracic epidural anesthesia in children as old as 10 yr. Ease of removal of the stylet, ease of injection, and negative aspiration and test doses predict successful placement and obviate the need for routine radiographic confirmation of catheter position.     

Combined spinal epidural anaesthesia: a new technique

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

A simple technique to reduce the incidence of accidental dural puncture

We would like to respond to recent comments (Reynolds. Anaesthesia 2001: 56 : 1129) on our epidural technique. In our practice we apply loss of resistance to air technique, which helps identify a nick in the dura with a small leak of CSF. On many occasions, only a few drops of CSF and not a constant leak helped identify dural puncture, which could have been missed with the use of saline. Upon inserting the epidural needle, we remove the stylet when the needle is engaged in the interspinous ligament or the ligamentum flavum. Very often, it is difficult for our residents to advance the epidural needle with one hand and apply constant pressure on the plunger with the other hand. Excessive pressure with one hand, by a resident, had caused dural puncture when the needle was pushed in too far. By reinserting the stylet with each advancement of the needle, we remove tissues that may enter and occlude the epidural needle. It is quite possible that constant plunger pressure with saline may also avert this problem.     

Thoracic epidural catheters via the caudal and lumbar approaches using styletted multiple port catheters in pediatric patients: a report of three cases

Advancing catheters from the lumbar and caudal epidural spaces to the thoracic level has been reported to be an alternative to the direct thoracic approach. However, as children grow, the threading of catheters in the epidural space becomes increasingly difficult. This report describes three cases of thoracic epidural placement using a multiport catheter threaded from the caudal and lumbar spaces using electrical stimulation guidance. In the first case, a multiport catheter was threaded 22 cm from the lumbar space to T8 following a failed attempt with a single-port catheter in a 9-year-old boy scheduled to undergo a right nephrectomy. In the second case, a multiport catheter was threaded 26 cm from the caudal space to T9 in a 3-year-old girl undergoing fundoplication. In the last case, a multiport catheter was inserted at the completion of a fundoplication in a 2-year-old girl after it had been confirmed that the single-port catheter inserted prior to surgery had not advanced to the desired thoracic level. The multiport catheter was threaded 17 cm without resistance from the caudal space to T9. In all cases, electrical stimulation was used to confirm the location of the catheter tip at the time of insertion. The position of the catheters was later confirmed by X-ray. The multiport catheter incorporates a stylet, which extends to a closed distal tip, within a catheter body that ejects fluid from three lateral holes in a direction perpendicular to the advancing catheter. These properties may facilitate the reliable advancement of catheters in the epidural space.     

201 combined spinal-epidurals for anaesthesia using a separate needle technique

BACKGROUND AND OBJECTIVE: Combined spinal-epidural (CSE) anaesthesia may be performed using separate needles or by passing the spinal needle through an epidural needle. The latter technique requires that subarachnoid block is performed before the epidural catheter is placed. This paper examines a series of 201 consecutive CSEs performed with a novel separate needle technique, designed to avoid potential and actual problems associated with the CSE technique. METHODS: The CSE technique involved placement of the spinal needle in the subarachnoid space, followed by replacement of the spinal needle stylet. The epidural catheter was then positioned separately before returning to the spinal needle and injecting the subarachnoid drug. RESULTS: The technique had a high technical success rate. Both needles were successfully placed in 200 (99.5%) cases. Spinal anaesthesia was successful in all cases. The epidural catheter was used in 179 cases and failure of the epidural occurred in 2 (1.1%) cases. Paraesthesia, inability to advance the epidural catheter or blood in the epidural catheter occurred in 31 (15.4%) and necessitated immediate replacement of the epidural catheter in 14 (7%) cases. Postoperatively, typical post-dural puncture headache was reported by one patient (0.5%) and mild backache by four (2%). There were no neurological complications. CONCLUSIONS: This method of CSE anaesthesia can be associated with high success and low complication rates.     

The Fiberscopic Findings of the Epidural Space in Pregnant Women

Background: The spread of epidural analgesia is facilitated by pregnancy. Changes in the epidural structure during pregnancy may affect the spread of analgesia in pregnant women. To investigate the changes in the epidural space produced by pregnancy, the authors performed epiduroscopy in pregnant women.

Methods: Using a flexible fiberscope, the authors evaluated the epidural space in 73 women undergoing lumbar epidural anesthesia. Patients were classified into three groups: a nonpregnant group (n = 21), a first trimester pregnant group (8-13 weeks, n = 23), and a third-trimester pregnant group (27-39 weeks, n = 29). A 17-gauge Tuohy needle was inserted using the paramedian technique and the loss-of-resistance method with 5 ml air. The epiduroscope was introduced into the lumbar epidural space via the Tuohy needle and was advanced approximately 10 cm in a cephalad direction from the needle tip within the epidural space. The differences in the epidural space among the three groups then was evaluated.

Results: The epiduroscopy showed that the epidural pneumatic space, after injection of a given amount of air, was narrower and the density of the vascular network greater in the third-trimester group than in the other two groups. The amount of engorged blood vessels was greater in the third and first trimester groups than in the nonpregnant group. The amount of bleeding at the needle tip and the amount of fatty and fibrous connective tissue did not differ among the three groups.     

Extent and duration of isobaric 0.5% bupivacaine spinal anesthesia by using new open-end pencil point spinal needle

Extent and duration of isobaric 0.5% bupivacaine spinal anesthesia by using two spinal needles; a new 25 gauge open-end pencil point spinal needle (needle tip is open as a hole after pulling out the stylet, Doctor Japan Co., Japan) and a 25 gauge Quincke needle (TOP Co., Japan) were studied clinically in 24 patients for elective lower extremity surgery. Patients were randomly assigned into two groups of 12 patients each according to the spinal needle used. Lumbar puncture was performed between L3-4 with the patient in lateral decubitus position. After isobaric 0.5% bupivacaine 4.0 ml was injected in 20 seconds, the patient was placed in supine position, and the onset of anesthesia was assessed by loss of cold sensation (alcohol sponge), sensory block (pinprick) and motor block (modified Bromage's scale) in every 5 minutes until 30 minutes. Recovery of motor block and adverse effects were assessed by a blinded observer. Sensory block at 30 minutes by Quincke needle was Th 8.4 +/- 1.0 and by new open-end pencil point needle it was Th 8.5 +/- 3.2 dermatomes. Two groups did not differ significantly in sensory block and also in motor block. No adverse effect was observed in both groups. These results indicate that this new open-end pencil point spinal needle is very useful for preventing adverse effects of spinal anesthesia.     

Can continuous low current electrical stimulation distinguish insulated needle position in the epidural and intrathecal spaces in pediatric patients?

BACKGROUND: Muscle twitches elicited with electrical stimulation (6-17 mA) during epidural insertion indicate correct epidural needle placement while muscle twitches at a lower current (<1 mA) may indicate intrathecal needle placement. This study examined whether applying continuous electrical stimulation at 6 mA could indicate needle entry into the epidural space without inadvertently penetrating the intrathecal space. METHODS: After institutional review board (IRB) approval, 10 pediatric patients scheduled for lumbar puncture were studied. Following sedation with propofol, an insulated 24-gauge Pajunck unipolar needle was inserted through an 18-gauge introducer needle placed at the L4-5 interspace. The needle was first connected to a nerve stimulator (6 mA) and advanced. At the first sign of muscle twitching, needle advancement was stopped and the threshold current for motor activity was determined. The current was then turned off, the stylet was removed and the needle checked for cerebrospinal fluid (CSF). If CSF was not present, the needle was advanced into the intrathecal space (as confirmed by the presence of CSF). Ten pediatric patients (ASA II or III) aged 7.8 +/- 4.3 years (2.8-16.0 years) were studied. RESULTS: All patients had two distinguishable threshold currents as the needle advanced. The mean threshold current to elicit muscle twitch in the presumed epidural space was 3.84 +/- 0.99 mA. CSF was not present in any of the patients at this location. The mean threshold current in the intrathecal space was 0.77 +/- 0.32 mA. The average estimated distance from the first threshold location to the intrathecal space was 3 mm. All muscle twitches were at the L3-5 myotomes. Nine muscle twitches were unilateral and one was bilateral. CONCLUSIONS: Monitoring with an insulated needle with electrical stimulation at 6 mA may prevent unintentional placement of epidural needles into the intrathecal space.     

The electrical properties of epidural catheters: what are the requirements for nerve stimulation guidance?

We designed the present study to investigate the electrical resistance of commercially available epidural catheters and to search for products and procedures suitable for nerve stimulation-guided insertion. Four types of epidural catheters were evaluated: 2 nonwire-reinforced catheters (19-gauge and 20-gauge nylon) and 2 wire-reinforced catheters (19-gauge without stylet and 20-gauge with stylet). The resistance of a catheter was calculated from the voltage level proportional to the fixed resistance in series circuit. In case of physiologic saline, the resistance of nonreinforced catheters was more than 700 kOmega, whereas the wire-reinforced catheter was 14.4 +/- 0.20 kOmega without stylet and 10.1 +/- 0.42 kOmega with stylet. When the stylet was passed through a 20-gauge nylon catheter, the resistance decreased to 49.2 +/- 1.96 kOmega. When catheters were primed with 10% hypertonic saline, the resistance of both nonreinforced catheters decreased by one third compared with physiologic saline. The electrical resistance of the saline-filled epidural catheters significantly differed among products tested. We conclude that epidural catheterization that is guided by electrical stimulation should be performed only with catheters equipped with spiral stainless steel wire reinforcement or with a stainless steel stylet.     

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

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

A case of femoral neuropathy after radical ovariectomy

We experienced a 55-year-old female patient who was diagnosed as femoral neuropathy after radical ovariectomy. An epidural catheter was introduced at T11-12 interspace without any problems and general anesthesia was induced and maintained. The operation ended uneventfully. On the first postoperative day, she noticed hypesthesia of the inner surface of her left thigh and could not raise the left leg. The symptom remained after the removal of epidural catheter on the second postoperative day, and the influence of insertion of the epidural catheter on the symptom was suspected. We performed neurological examinations and found weakness of the left quadriceps femoris muscle, weakness of the left patellar reflex, and weakness of touch sensation and cold sensation and hypalgesia on the anterior surface of the left thigh and the inner surface of the left lower leg. Those findings led us to diagnose with femoral neuropathy probably due to abdominal retractors or the operation itself, and insertion of epidural anesthesia could not be the cause of neuropathy. Her symptom was ameliorated with a conservative therapy after four months. We should perform fine neurological examinations when neurological complications occur, especially when we use epidural catheters, and also should have the knowledge about those complications.     

Thoracic epidural analgesia via the lumbar approach using nerve stimulation in a pediatric patient with Down syndrome

This case illustrates the threading of an epidural catheter with electrical stimulation guidance from the lumbar epidural space to the thoracic space in a pediatric patient. A 17-year-old boy with Down syndrome, weighing 48 kg, was scheduled to undergo a laparotomy for duodenal obstruction and gastrostomy tube insertion. Combined general and continuous epidural anesthesia was selected for his anesthetic. Following the induction of general anesthesia and tracheal intubation, a 17G Tuohy needle (Arrow International, Inc., Reading, PA) was inserted into the lumbar space (L3-4) using loss of resistance with air. A 20G styletted epidural catheter was then inserted and threaded cranially. As the catheter was advanced, a low electrical current (1-10mA) was applied to the catheter. Motor response was observed from the lower limb muscles to the upper abdominal muscles as the catheter advanced cranially. After 22 cm of the epidural catheter had been inserted, intercostal muscle movement (T9 - 10) was observed at 3.0 mA. Radiographical imaging later confirmed the catheter tip at T10. The patient awoke without distress and was discharged to the ward with subsequent good pain control from a continuous epidural infusion of bupivacaine 0.1% with 1 microg ml(-1) fentanyl at 4-6 ml(-1).     

Multiple neurinoma of the spinal cord: case report

The patient, a 72-year-old female, was admitted with an 11-year history of progressive dysesthesia in the left leg. Neurological findings on admission revealed weakness in the bilateral legs, hyperreflexia of left leg, hypalgesia and hypesthesia under the Th 8 level, and urinary incontinence. Plain lumber X-ray showed enlargement of the intervertebral foramen of L 1/2. Myelography disclosed block age at the level of Th 9 and filling defect at the level of Th 10/11 and L1/2. CT myelography revealed a cord swelling and partially exophytic tumor from Th 8 to Th 9, another tumor located posterior-laterally at the level of Th 11, and another tumor located extra and intradural at the level of L1/2. Laminectomy was performed from Th 8 to L 3. A tumor of the Th 9 was located intramedullary, another tumor of the Th 11 was located intradural extramedullary, and another tumor of the L1/2 was located in the epidural space (so-called dumb-bell type tumor). These tumors were removed completely except the extra-canal part of L1/2 tumor. Histopathological examination revealed typical Antoni type A schwannoma in all tumors. This case was considered multiple neurinomas of the spine in which tumors were located in three separate anatomical sites, intramedullary, intradural extramedullary, and epidural sites. This patient did not show café-au-lait spot, and neurofibroma in her body. The authors considered the patient might be a case of central neurofibromatosis. The authors stressed that multiple neurinomas of the spine is not rare, so careful study of the whole spine is necessary including its intramedullar space.     

The fiberscopic findings of the epidural space in pregnant women

BACKGROUND: The spread of epidural analgesia is facilitated by pregnancy. Changes in the epidural structure during pregnancy may affect the spread of analgesia in pregnant women. To investigate the changes in the epidural space produced by pregnancy, the authors performed epiduroscopy in pregnant women. METHODS: Using a flexible fiberscope, the authors evaluated the epidural space in 73 women undergoing lumbar epidural anesthesia. Patients were classified into three groups: a nonpregnant group (n = 21), a first trimester pregnant group (8-13 weeks, n = 23), and a third-trimester pregnant group (27-39 weeks, n = 29). A 17-gauge Tuohy needle was inserted using the paramedian technique and the loss-of-resistance method with 5 ml air. The epiduroscope was introduced into the lumbar epidural space via the Tuohy needle and was advanced approximately 10 cm in a cephalad direction from the needle tip within the epidural space. The differences in the epidural space among the three groups then was evaluated. RESULTS: The epiduroscopy showed that the epidural pneumatic space, after injection of a given amount of air, was narrower and the density of the vascular network greater in the third-trimester group than in the other two groups. The amount of engorged blood vessels was greater in the third and first trimester groups than in the nonpregnant group. The amount of bleeding at the needle tip and the amount of fatty and fibrous connective tissue did not differ among the three groups. CONCLUSIONS: Epidural blood vessels become engorged in the first trimester; the density of the vascular networks increase in the third trimester. These changes in the epidural space during pregnancy may affect the spread of epidural analgesia in pregnant women.