Epidural Catheter Insertion Research Articles

Propofol Reduces Spinal Motor Neuron Excitability in Humans

Propofol Reduces Spinal Motor Neuron Excitability in Humans

Comparison of continuous thoracic epidural and paravertebral blocks for postoperative analgesia after minimally invasive direct coronary artery bypass surgery

Objective: To compare continuous thoracic epidural analgesia (TEA) and paravertebral block (PVB) for postoperative analgesia in patients undergoing minimally invasive direct coronary artery bypass (MIDCAB) surgery for quality of analgesia, complications, compliance to chest physiotherapy, hemodynamics, and respiratory effects. Design: Prospective, randomized study. Setting: Specialty research hospital. Participants: Forty-one consenting patients undergoing MIDCAB surgery. Interventions: Patients in the TEA group had an epidural catheter inserted at the T4-5 interspace, whereas patients in the PVB group had a catheter inserted in the paravertebral space on the left side at the T4-5 level. Measurements and Main Results: Parameters evaluated included visual analog scale pain scores at rest and while coughing, supplemental analgesic requirement, complications, hemodynamics, and respiratory parameters. Measurements were made at 2-hour intervals for 12 hours beginning at 10 minutes after endotracheal extubation. There was no statistically significant difference in visual analog scale scores and requirement of supplemental analgesia between the 2 groups. Cardiac index at 4 hours and 6 hours was significantly higher in the TEA group. Patients in the PVB group had significantly lower respiratory rates at 8, 10, and 12 hours. All other parameters were comparable. In 1 patient, the epidural space could not be catheterized. One patient in the TEA group had transient hypotension, and 1 patient complained of backache at the site of the epidural catheter insertion. Conclusion: PVB is as effective as TEA for postoperative analgesia after MIDCAB surgery. PVB is technically easier than TEA and may be safer than TEA because no complications were seen in the PVB group. Copyright © 2001 by W.B. Saunders Company

A case of awareness with sevoflurane and epidural anesthesia in ovarian tumorectomy

We experienced a case of awareness during ovarian tumorectomy in a patient who was anesthetized with sevoflurane and epidural anesthesia. A 74-year-old woman was scheduled for resection of an ovarian tumor. After epidural catheter insertion, anesthesia was induced with 60 mg of propofol and 6 mg of vecuronium, and anesthesia was maintained with epidural anesthesia (1% mepivacaine), 1 to 2% sevoflurane, and 66% nitrous oxide in oxygen. The operative course was uneventful and the total operation time was 2 hours and 50 minutes. Two days after the operation, we were surprised to learn that the patient complained of awareness during the surgery.

Influence of body mass index on adverse events during epidural puncture and catheter insertion in parturients

Influence of body mass index on adverse events during epidural puncture and catheter insertion in parturients

Is anticoagulation and central neural blockade a safe combination?

The indiscriminate insertion of epidural or subarachnoidal needles or catheters in patients who are anticoagulated or are about to be anticoagulated carries the inherent risk of the potential development of a compressing vertebral canal haematoma, which may severely jeopardize the patient's (quality of) life. Although the isolated use of aspirin or non-steroidal anti-inflammatory drugs in general is no longer considered a problem, its combination with any form of heparin therapy is. Intraoperative heparinization during cardiac or vascular surgery can be safely performed provided a minimum time interval between the regional anaesthetic block and the subsequent heparinization is respected and indwelling catheters are removed after the disappearance of any remaining heparin effect. Similarly, central neural blockade in combination with the thromboprophylactic use of standard unfractionated heparin or low-molecular-weight heparins is possible if: (1) only thromboprophylactic heparin doses are used; and (2) a specific minimum time interval between the previous or the next dose of the anticoagulant and the initiation of the block or the removal of the indwelling catheter is observed.

Does epinephrine improve the diagnostic accuracy of aspiration during labor epidural analgesia?

Aspiration reliably detects almost all IV multiorifice epidural catheters. Although a supplemental epinephrine 15-microg test dose may detect the rare IV catheter that does not yield blood on aspiration, false-positive epinephrine responses may cause some women to unnecessarily undergo repeat epidural catheter insertion. We evaluated 532 consecutive eligible patients requesting neuraxial labor analgesia. Patients were excluded if they had a contraindication to epinephrine or if they received intrathecal sufentanil/bupivacaine. Multiorifice catheters were inserted 4-6 cm into the epidural space as part of an epidural (n = 305) or combined spinal-epidural (n = 270) technique. We used aspiration, a lidocaine/epinephrine test dose, and bolus injection or infusion of dilute bupivacaine/sufentanil solutions to systematically determine IV, intrathecal, or epidural catheter location. Aspiration alone detected 47 of 48 intravascular catheters. There were 10 positive epinephrine responses: 2 were true positives, 7 were falsely positive (subsequent local anesthetic injection/infusion produced bilateral sensory change and analgesia), and 1 catheter was removed without further testing. Aspiration detected almost all intravascular catheters. Although the epinephrine test dose did detect one catheter that proved to be in a blood vessel, 87.5% of positive responses occurred in women without intravascular catheters. Epidural catheters may enter a blood vessel. Many clinicians use epinephrine to detect these catheters. Because aspiration alone detects almost all IV multiorifice catheters in laboring women, a subsequent epinephrine test dose may be unnecessary.

The Effects of Needle Bevel Orientation During Epidural Catheter Insertion in Laboring Parturients

Lateral needle bevel orientation during identification of the epidural space has been recommended to reduce the risk of postdural puncture headache (PDPH).Rotation to cephalad or caudad orientation before catheter insertion is assumed necessary for analgesic success. We prospectively compared the effects of catheter insertion through lateral- and cephalad-oriented Tuohy needle bevels in laboring parturients. Anesthesiology residents were randomized to identify the epidural space with bevels oriented cephalad or lateral. Catheters were inserted without needle rotation. Outcomes compared included ease of insertion, analgesic effectiveness, and complications. We evaluated 534 catheter insertions in 500 parturients. Initial catheter insertion produced satisfactory analgesia in 80.2% of the lateral group versus 91.1% of the cephalad group (P < 0.001). Resistance preventing catheter insertion accounted for the difference. There were no differences in IV cannulation (5.8% vs 5.1%), dural puncture (3.8% vs 2.0%), PDPH (0.4% vs 0.7%), or asymmetric block (31% vs 27%). There was a slightly higher rate of paresthesias in the lateral group (31% vs 23%; P = 0.048). In 78% of parturients experiencing both paresthesias and asymmetric block, the side of the paresthesia and greater extent of block were the same. Analgesic effectiveness, as measured by using a visual analog scale, was not different between the groups. Implications: Two methods of epidural catheter insertion were compared in laboring parturients. Catheter insertion with the needle orifice oriented cephalad was associated with the greatest initial success and the fewest complications. (Anesth Analg 1999;88:352-6)

DETERMINATION OF DOSE RESPONSE FOR INTRATHECAL ROPIVACINE IN LABORING PARTURIENTS

S268 INTRODUCTION: Using the combined spinal epidural (CSE) technique, intrathecal injections of low doses of local anesthetics and/or opioids are being increasingly used for labor analgesia. Ropivacaine, a newly introduced amide local anesthetic, has been shown to be minimally cardiotoxic and results in less motor block than the traditional bupivacaine, [1,2] when used epidurally. Intrathecal ropivacaine has been recently used for general surgery [3] and labor analgesia. [4] The purpose of this study was to determine the ideal intrathecal dose of ropivacaine which would provide adequate labor analgesia with minimal or no motor blockade, and without adversely affecting the mother, fetus, or progress of labor. METHODS: Following institutional approval and written informed consent, twenty healthy, term parturients aged 15-35 years who requested analgesia for labor, participated in the study. All parturients received pulmonary aspiration prophylaxis and 200 cc bolus of lactated Ringer's solution intravenously. The parturients were randomized into five groups in a double blinded manner: Group A - fentanyl 15 mcg (n = 4), Group B - ropivacaine (ropi) 0.5 mg + fentanyl 15 mcg (n = 3), Group C - ropi 1.0 mg + fentanyl 15mcg (n = 6), Group D - ropi 1.5 mg + fentanyl 15mcg (n = 4), Group E - ropi 2.0 mg + fentanyl 15mcg (n = 3). Using the needle through needle technique {Tuohy 17 gauge and Whitacre 27 gauge (11.9cm)}, all parturients received fentanyl 15 mcg intrathecally (with or without ropivacaine), followed by epidural catheter insertion. The epidural block was maintained with ropivacaine 0.1 % and fentanyl 2 mcg/ml infusion after patient's request for further analgesia. Visual analog pain scores (VAS) were assessed before and after the intrathecal dose, and epidural block. Sensory and motor blockade were assessed by pinprick and modified Bromage scale, respectively. Hemodynamic parameters, onset and duration of analgesia, duration of first and second stages of labor, and neonatal Apgar scores were recorded. Parturients were assessed twenty-four hours postpartum for satisfaction with analgesia, and for side effects. RESULTS: There were no demographic differences in the five study groups. All subjects had satisfactory analgesia at 5 minutes after the block. The mean duration of analgesia with intrathecal fentanyl was 80 +/- 10.8 minutes, while in combination with ropivacaine, it was 151.93 +/- 34.45 minutes (p = 0.001), which is statistically significant according to the independent sample T-test. One way ANOVA on the five treatment groups showed significant difference in duration of analgesia across groups (p = 0.001), while multiple comparison analysis determined a significant difference between groups A and C (p = 0.004). The mean duration of the first and second stages of labor were 458.10 +/- 169.77 minutes (p = 0.614) and 35.35 +/- 8.76 minutes (p = 0.328), respectively, with no significant difference across groups. Average time interval between intrathecal injection and delivery was 302.75 +/- 130.61 minutes. Neither the VAS pain scores at 1 and 5 min (p = 0.107, 0.835) nor the changes in VAS pain scores at 1 and 5 min (p = 0.349, 0.883) were significantly different across groups. Fisher's exact test showed no significant difference in motor blockade (detectable weakness of hip flexion) between fentanyl and fentanyl/ropivacaine groups (p = 0.587). Sensory blockade to pin prick was not discernible in 50% of subjects. No significant differences in hemodynamic parameters, umbilical cord gases, or neonatal Apgar scores were noted between the five groups. Two parturients {group C, n=1, group E, n=1} required cesarean section for failure at progression of labor. All patients were satisfied with labor analgesia. None of the parturients experienced postpartum headache, neurological problems, or urinary retention. CONCLUSION: In this ongoing study, our findings suggest that intrathecal ropivacaine (0.5 to 2.0 mg) with fentanyl 15 mcg provides instantaneous analgesia for laboring parturients, without compromising maternal or fetal safety. Our preliminary data, statistically and clinically, suggests that the combination of fentanyl and low dose ropivacaine prolongs the duration of labor analgesia. The addition of ropivacaine does not produce any motor block and may allow ambulation. We recommend the use of low dose ropivacaine and fentanyl 15 mcg intrathecally in the combined spinal epidural technique for labor analgesia.

Skin to cervical epidural space distances as read from magnetic resonance imaging films: consideration of the “hump pad”

Study Objective: To measure the distances from the skin to the epidural space (DSES) of the lower cervical and upper thoracic intervertebral spaces. Design: Retrospective review of films of the cervical spine as obtained by magnetic resonance imaging (MRI). Setting: Health care facility that provides diagnosis and treatment of patients with chronic pain. Measurements and Main Results: MRI sagittal films of 100 patients, who had diagnostic studies for chronic headaches and cervicobrachial radiculopathy, were reviewed. Measurements were made of DSES, the dural sac, and the spinal cord by centimeter ruler. Estimates were also made of the width of the epidural space by measuring the distance from the ligamentum flavum to the dural sac. The longest DSES were noted at C6–7 and C7–T1 levels, with a mean of 5.7 cm, but they decreased to a mean of 5.4 cm at the T1–2, and to 4.7 cm at the T2–3 intervertebral spaces. One of the major factors in this variability was the presence of an accumulation of fatty tissue along the lower cervical and upper thoracic area, which the authors named the “hump pad.” This accumulation appears to be thicker in obese patients, with a slight correlation coefficient with the patient’s weight. The distances from ligamentum flavum to dural sac, representing the depth of the epidural space, averaged 0.3 cm, 0.4 cm, 0.5 cm, and 0.4 cm, respectively. Conclusions: In the cervical spine, DSES varies from space to space. In obese individuals, the fat pad may increase DSES at the lower cervical intervertebral spaces. The longest mean distances from the ligamentum flavum to the dural sac and to the spinal cord were found at the T1–2 and T2–3 levels, precisely where DSES is shorter. All things being equal, the upper thoracic intervertebral spaces appeared to provide a greater margin of safety for insertion of epidural catheters to treat cervicobrachial radiculopathies.

Postdural Puncture Headache and Epidural Blood Patch

Department of Anesthesiology (Borum).Department of Radiology; Texas A&amp;M University Health Science Center (Naul).Department of Anesthesiology; Scott &amp; White Clinic and Memorial Hospital; Scott, Sherwood and Brindley; Texas A&amp;M University Health Science Center; College of Medicine; Temple, Texas (McLeskey).(Accepted for publication June 19, 1997.)In Reply:-We agree with Dr. Shah that our case report illustrates the difficulty in the diagnosis of postpartum headache, although his suggestion that a cerebrospinal fluid (CSF) leak be demonstrated before performing epidural blood patch for postdural puncture headache (PDPH) does not conform with current practice. [1–3] The history of dural puncture followed by a postural headache establishes the diagnosis in a manner sufficient to proceed with epidural blood patch.Shah advocates the insertion of an epidural catheter for establishing the presence of low CSF pressure [4] and CSF leak and for injection of the epidural blood patch. Although effective in supporting the diagnosis of PDPH, epidural catheter insertion could have several drawbacks, if used in all cases of PDPH. Because the epidural blood patch should be injected as close to the site of dural puncture as possible [1,5,6] and because the spread of the blood is typically cephalad, [7] the insertion of a catheter might reduce the accuracy of the injection. Also, vascular injury by the catheter could cause bleeding in the epidural space, thus unnecessarily increasing the volume of the blood patch.Shah has suggested that epidural catheter insertion for CSF aspiration might be helpful when a patient has a postural headache after multiple attempts at epidural needle placement and when the stilette was not removed from the needle, resulting in the possibility of an unrecognized dural puncture. [8] In our case report, the atypical headache appeared after the second epidural blood patch. An epidural catheter inserted at this time might have entered the previously placed blood patch, thus rendering pressure measurements and aspiration testing useless.Stanley E. Borum, M.D.Department of AnesthesiologyL. Gill Naul, M.D.Department of Radiology; Texas A&amp;M University Health Science CenterCharles McLeskey, M.D.Department of Anesthesiology; Scott &amp; White Clinic and Memorial Hospital; Scott, Sherwood and Brindley; Texas A&amp;M University Health Science Center; College of Medicine; Temple, Texas

Comparison of Continuous Spinal with Combined Spinal-Epidural Anesthesia Using Plain Bupivacaine 0.5% in Trauma Patients

We investigated the efficacy and complications of microcatheter spinal anesthesia (CSA) in comparison to a combined spinal-epidural technique (CSE) using plain bupivacaine 0.5%. Sixty trauma patients randomly received either CSA using a 22-gauge Sprotte needle and a 28-gauge microcatheter or CSE after insertion of a 22-gauge epidural catheter through an 18-gauge Tuohy needle followed by dural puncture with a 25-gauge pencil-point needle inserted through the backeye of the Tuohy needle. An initial subarachnoid bolus of 2 mL of plain bupivacaine 0.5% was injected. If analgesia did not reach T12 within 20 min, supplemental bupivacaine was injected either intrathecally or epidurally up to a maximum of 5 mL in the CSA group or 16 mL in the CSE group. Mean arterial blood pressure, heart rate, and analgesic levels were recorded. On postoperative Day 4, patients were interviewed for postanesthetic complaints. Technical problems were more frequent in the CSE group than in the CSA group (47% vs 13%). Performance of anesthesia was faster (8 +/- 3 vs 15 +/- 8 min) and the total dose of bupivacaine lower (3.2 +/- 1.0 vs 9.7 +/- 5 mL) in patients who received CSA. The incidence of hypotension did not differ significantly. However, more patients in the CSE group were treated for bradycardia (4 vs 0). The number of patients suffering from postdural puncture headache was comparable in both groups, but there were more patients with lower back pain in the CSE group (8 vs 2). In conclusion, our data suggest that microcatheter CSA is not associated with an increased rate of complication in patients with lower limb fractures. (Anesth Analg 1997;85:69-74)

Reply

Assistant Professor of Anesthesiology (D'Angelo); Instructor of Anesthesiology (Gerancher), Section of Anesthesiology, Section of Obstetric Anesthesia, Department of Anesthesia, Wake Forest University Medical Center, Bowman Gray School of Medicine, Winston-Salem, North Carolina 27157.In Reply:-We appreciate Moore's interest in our uniport epidural catheter insertion study [1]; however, it appears quite clear that he has misinterpreted the focus, findings, and conclusions of this study. In his criticism, Moore refers to recommendations on epidural catheter insertion by Brown, [2]Shnider et al., [3]and Bromage. [4]Ironically, recommendations such as these were the specific impetus for our evaluation of epidural catheter insertion. These recommendations are based solely on “clinical experience” rather than systematic, scientific examination. Our study was the first prospective randomized study to systematically evaluate uniport epidural catheter insertion in laboring patients.Moore asks, “Can investigations based on clinical performance … determine precisely the optimal distance to insert lumbar catheters in mobile patients?” Our anesthetic practice involves direct clinical patient care; therefore, actual patients are the most appropriate model in which to ask, examine, and attempt to answer clinical questions. Volunteer or animal studies would provide little clinically relevant information for this patient population. In addition, Moore suggests that roentgenographic studies were necessary after delivery to “conclusively prove the optimal distance to insert lumbar epidural catheters….” We believe that postdelivery roentgenograms would provide no clinically pertinent information. Documenting the particular distance within the epidural space an epidural catheter's distal tip rests after delivery would provide irrelevant information. What is relevant is that the patient experienced adequate analgesia throughout labor and delivery.Moore seeks irrefutable proof of the “optimal distance” an epidural catheter should be inserted into a mobile patient. Our findings indicate that no single insertion length is ideal for all patients; and, we conclude that epidural catheter insertion should vary, depending on the expected duration of labor. Uniport epidural catheters should be inserted either 2 cm when rapid labor is anticipated or 6 cm when longer labors or cesarean section are anticipated. In addition, even optimal insertion distances will only reduce the risk of complications, not eliminate them.Moore further states, “Neither Beilin et al. [5]or D'Angelo have presented anything new.” We emphatically disagree. These studies were the first prospective randomized examinations of multiport and uniport epidural catheter insertion in laboring patients, respectively. Findings and conclusions from both studies are remarkably similar, yet differ considerably from the aforementioned recommendations [2–4]based on “clinical experience.” We have changed our practice and our teaching to reflect what we have learned from our patients. Clinicians may now choose an epidural catheter insertion length that minimizes associated complications in laboring patients.Robert D'Angelo, M.D.Assistant Professor of AnesthesiologyJ.C. Gerancher, M.D.Instructor of AnesthesiologySection of Obstetric Anesthesia; Department of Anesthesia; Wake Forest University Medical Center; Bowman Gray School of MedicineWinston-Salem, North Carolina 27157(Accepted for publication December 12, 1996.)

Oral anticoagulant prophylaxis and epidural catheter removal.

The use of regional anesthesia in patients receiving anticoagulants is controversial. The purpose of this review is to document the incidence of neurologic complications with insertion and removal of an epidural catheter in patients receiving oral anticoagulants and antiplatelet medication. A retrospective review was made of the charts of 459 patients who underwent hip pinning or hip or knee replacement under regional anesthesia and received postoperative epidural analgesia and warfarin thromboembolism prophylaxis. The number of patients receiving preoperative antiplatelet therapy and warfarin, as well as baseline coagulation parameters, was documented. For patients who had postoperative epidural analgesia, the prothrombin time on the day of epidural catheter removal was obtained. Neurologic complications during the hospital stay were noted. Spinal anesthesia was administered to 47 patients and epidural anesthesia and postoperative analgesia to 412. Before surgery, antiplatelet therapy was given to 270 and warfarin to 180 patients, with some patients receiving both. The mean +/- SD preoperative prothrombin and partial thromboplastin times were 10.8 +/- 1.2 seconds (normal, 9.6-11.1 seconds) and 27.5 +/- 3.5 seconds (normal, 24.6-33.2 seconds), respectively. Blood on needle or catheter insertion was noted in 21 patients, all of whom were taking antiplatelet medication and/or warfarin. Epidural catheters remained postoperatively for a mean of 43.6 +/- 12.5 hours (range 5-118 hours). The mean prothrombin time on the day of epidural catheter removal was 14.1 +/- 3.2 seconds. Four postoperative peripheral neuropathies were detected. There was no clinical evidence of spinal hematoma in any patient. Epidural catheter placement and removal in patients taking oral anticoagulants appears to be safe. Careful monitoring of the patient for evidence of spinal hematoma after epidural catheter removal is recommended.

Prospective Examination of Epidural Catheter Insertion

Prospective Examination of Epidural Catheter Insertion

Enoxaparin and Epidural Analgesia

Department of Anesthesia, University of California, San Francisco, 521 Parnassus Avenue, San Francisco, California 94143–0648.To the Editor:--Enoxaparin sodium (Lovenox), a low molecular weight heparin (LMWH) manufactured by Rhone-Poulenc Rorer Pharmaceuticals, has a new warning included in its recently changed package insert. This change can have significant implications for anesthesiologists. It states “Lovenox injection, like other anticoagulants, should be used with extreme caution in conditions with increased risk of hemorrhage, such as [1]… in patients with indwelling intrathecal or epidural catheters, …” Because of this warning, some orthopedic surgeons at our institution have decided against the use of an epidural catheter for postoperative pain management in patients receiving Lovenox for deep venous thrombosis (DVT) prophylaxis after total hip and knee replacement surgery.Lovenox was released for use in Europe in 1987 and in the United States in 1993. Bergqvist et al. [1]reported that of more than one million patients receiving LMWH, there was one case of a spinal hematoma. In other controlled studies of at least 10,000 patients who received epidural/spinal anesthesia or analgesia during LMWH prophylaxis, this combination of treatments did not produce any catheter-related complication. [1,2]A similar safety record was observed in three other studies of 1,792 patients. [2–4]In contrast, during post-market clinical use in the United States since 1993, Rhone-Poulenc Rorer Pharmaceuticals reports that there have been seven cases of epidural hematoma formation after epidural anesthesia/analgesia in association with Lovenox use. All but two cases were associated with an epidural catheter that was inserted or removed, either before the patient was started on Lovenox. Because of this new development, the drug manufacturer recently changed the package insert to reflect the perceived increased risk of epidural hematoma formation in patients with an epidural catheter during Lovenox prophylaxis.Epidural hematoma formation in patients receiving anticoagulation therapy is a known but rare complication irrespective of central neuraxial blockade. Is the risk of spontaneous or catheter-related spinal hematoma greater with Lovenox than with other effective forms of anticoagulant DVT prophylaxis? Is it safe to leave an indwelling epidural catheter for postoperative analgesia or to remove it during Lovenox therapy? Although we are now aware of the seven cases of epidural hematoma reported by Rhone-Poulenc Rorer in the past 2 yr, we cannot estimate the incidence of epidural hematoma formation in patients receiving Lovenox and have an epidural catheter, because the number of patients receiving intraoperative and/or postoperative epidural anesthesia and/or analgesia is unknown. The perceived “high” incidence of epidural hematoma formation in patients receiving Lovenox may be explained by the increased use of epidural analgesia after total joint replacement surgery. Therefore, it may appear that specifically having a catheter in place increases the risk of epidural hematoma formation.We must identify whether the risk of epidural hematoma formation is related to the timing of epidural catheter insertion or catheter removal, or related to the duration of catheter indwelling; whether there is a relation between the administered dose of Lovenox and epidural hematoma formation. Information regarding the circumstances under which epidural hematoma occurred in the reported cases is lacking or incomplete. A cause-effect relation cannot be established at this time. A prospective determination of the incidence of epidural hematoma formation in patients with epidural catheters removed at the end of surgery and in patients whose catheter is left in place for postoperative analgesia is needed. There is no evidence in the literature that removal of an epidural catheter portends greater risk of epidural hematoma formation than does epidural catheter insertion.Finally, further studies are needed to delineate the role and effectiveness of epidural anesthesia and analgesia in improving outcome. Postoperative epidural analgesia is an excellent method for providing postoperative pain control, particularly in patients undergoing total hip and knee joint replacement. It would be unfortunate to abandon this form of postoperative pain management without further eludication of the risk:benefit profile for Lovenox and epidural anesthesia and analgesia.Sandra R. Weitz, MD; Vincent Chan, MD; Department of Anesthesia, University of California, San Francisco, 521 Parnassus Avenue, San Francisco, California 94143–0648.(Accepted for publication April 29, 1996.)

Epidural Catheter Insertion and Satisfactory Analgesia

Assistant Professor of Anesthesiology, Section of Obstetric Anesthesia, Department of Anesthesia, Wake Forest University Medical Center, Bowman Gray School of Medicine, Winston-Salem, North Carolina 27157, Electronic mail: rdangelo@bgsm.edu.In Reply:--The management of epidural catheters for laboring patients can be quite labor intensive: Michael et al [1]reported a 33% incidence of inadequate analgesia after insertion of uniport epidural catheters. Our study was designed to determine which insertion length minimizes insertion-related complications and the effectiveness of epidural catheter manipulation when associated with intravenous cannulation or unilateral sensory analgesia after insertion. In practical terms, can the time spent inserting and manipulating uniport epidural catheters be minimized?We concluded that uniport epidural catheters could be inserted either 2 or 6 cm within the epidural space based on the anticipated duration of labor. [2]Beilin argues that he cannot predict obstetric outcome and therefore would have concluded that all epidural catheters should be inserted 6 cm within the epidural space. I would argue that, although one cannot precisely predict the duration of labor for a given patient, the multiparous patient presenting in active-phase labor with a history of previous uncomplicated vaginal deliveries, on average, would deliver more quickly than the prima gravida or the multiparous patient presenting in latent-phase labor. In our study, we found that inserting uniport epidural catheters 2 cm minimizes insertion-related complications [2]; however, as Beilin notes, epidural catheters inserted 2 cm within the epidural space are more likely to subsequently dislodge. Although true, catheter dislodgment occurred in only 16 of 200 epidural catheters inserted 2 cm within the epidural space and dislodged an average 6.5 h after insertion, significantly longer than the reported mean 3.2-h duration of active-phase labor in the multiparous patient. [3]Therefore, based on these findings and despite Beilin's argument, I recommend inserting uniport epidural catheters 2 cm in the multiparous patient presenting in active-phase labor. In all other patients, I would insert epidural catheters 6 cm within the epidural space. In addition, as Beilin suggests, I would consider a combined technique in these patients but would insert the uniport epidural catheter 2 cm within the epidural space after the subarachnoid injection.Beilin questions our conclusion that epidural catheter manipulation may be more time-efficient than epidural catheter replacement because 65 min was required to achieve patient comfort in one patient in whom the epidural catheter was inserted 8 cm within the epidural space. Beilin also suggests that we should have either administered additional local anesthetic before catheter manipulation or automatically replaced epidural catheters associated with inadequate analgesia. However, as previously stated, one purpose of our study was to determine the effectiveness of catheter manipulation. Because catheter manipulation was effective in 91% of epidural catheters inserted &gt; 2 cm associated with unilateral analgesia and 50% of catheters inserted intravenously functioned well after catheter manipulation, I believe our recommendations regarding catheter manipulation are justified. I agree that 65 min to achieve patient comfort is an excessive amount of time. However, 783 other patients became comfortable in &lt; 65 min. In addition, clinical practice is not dictated by strict research protocol, and our clinical practice uses earlier, more aggressive catheter manipulation. Finally, regarding administration of additional local anesthetic before catheter manipulation, we know of no series that has randomly investigated the efficacy of administering additional local anesthetic in the presence of unilateral analgesia. However, we have observed that this practice, if ineffective, will delay achieving patient comfort that Beilin and we oppose. I believe the findings of our study can be applied in clinical practice. Currently, I insert epidural catheters 6 cm within the epidural space. If analgesia is inadequate 10–15 min after local anesthetic administration, I withdraw the catheter 3–4 cm and administer local additional anesthetic. If the patient is not comfortable within 10 min after additional drug administration, the epidural catheter is removed and replaced. As a result, the patient is either comfortable or the epidural catheter is replaced within 20 min of initial placement. This practice, I would argue, is expedient for the anesthesiologist and the patient.Robert D'Angelo, M.D., Assistant Professor of Anesthesiology, Section of Obstetric Anesthesia, Department of Anesthesia, Wake Forest University Medical Center, Bowman Gray School of Medicine, Winston-Salem, North Carolina 27157, Electronic mail: rdangelo@bgsm.edu.

Postoperative analgesia using epidural infusions of fentanyl with bupivacaine. A prospective analysis of 1,014 patients.

Epidural fentanyl/bupivacaine infusions often are limited to high dependency units or intensive care units. One thousand fourteen patients receiving epidural fentanyl/bupivacaine infusions for analgesia after major surgery who were managed in the general surgical ward were prospectively surveyed. Patients leaving the recovery room with an epidural catheter in situ were assessed three times a day by acute pain service personnel for quality of pain relief, using a rating scale that accounted for pain on movement. The presence of side effects and complications was assessed. Data were collected from February 1990 to May 1993. The average duration of infusion was 3 days. A patient's pain relief was rated as good to excellent on 82.6% of visits. Side effects possibly attributable to fentanyl included sedation (7.4%), pruritus (10.2%), nausea and vomiting (3.1%), and respiratory depression (1.2%). Respiratory depression commonly was associated with sedation and was detected easily on the postsurgical ward, with only four patients requiring naloxone (0.4%). Side effects possibly related to bupivacaine included unpleasant sensory block (2.6%), significant lower limb motor block (3.0%), and hypotension (6.6%). There were two cases of epidural hematoma. Inflammation at the epidural catheter insertion site occurred in 3.8% (38), of which 42% (16) had some cutaneous purulence detected. There were no epidural space infections. Mechanical problems, including dislodgment of the catheter, accounted for 18.7% of infusion discontinuations within the first 72 h. Postoperative epidural fentanyl/bupivacaine infusions are effective and can be managed readily in general postsurgical wards with minimal complications provided that appropriate patient observations are performed.

Does Epidural Catheter Insertion Length Make a Difference?

Does Epidural Catheter Insertion Length Make a Difference?

Complications of Labor Analgesia

Both epidural and combined spinal epidural (CSE) analgesia can provide maternal pain relief during labor. Currently, there are few data comparing the risks and complications of these two techniques. We recorded the incidence and severity of anesthetic-related complications in 1022 laboring parturients. Ninety-eight women opted for either no or parenteral analgesia, 388 chose epidural, and 536 requested CSE analgesia. Women choosing CSE analgesia most often received an intrathecal injection of sufentanil 10 micrograms at the time of epidural catheter insertion. The epidural catheters were then dosed as needed as the intrathecal analgesia waned. Women who received CSE analgesia were more likely to itch (41.4% vs 1.3%) or complain of nausea (2.4% vs 1.0%) or vomiting (3.2% vs 1.0%) than those receiving solely epidural analgesia. Patients who requested only epidural analgesia were more likely to suffer an unintended dural puncture (4.2% vs 1.7%). Fewer than 10% developed hypotension with either technique. The risk of headache was the same with both anesthetics (4%-10%) and did not differ from the incidence of headache in women not receiving neuraxial analgesia (10%-14%). Six patients required epidural blood patch for moderate to severe postural headache. Four of these women suffered a dural puncture with the 18-gauge Hustead epidural needle. The other two women had reportedly uncomplicated epidural and CSE analgesia. These data suggest either neuraxial analgesic technique can safely relieve the pain of labor. CSE analgesia is a safe alternative to epidural analgesia for labor and delivery.

Haemodynamic effects of position chosen for insertion of epidural catheter : A comparison of the lateral and sitting position

s of selected papers presented to the Obstetric Anaesthetists Association meeting in Manchester, 27 September 1991 HAEMODYNAMIC EFFECTS OF POSITION CHOSEN FOR INSERTION OF EPIDURAL CATHETER A comparison of the lateral and sitting position I. S. Chadwick, J. Eddleston, B. J. Pollard, C. K. Candelier University Department Anaesthetics, Manchester Royal Infirmary and St Mary’s Hospital, Manchester,