Equilibrium analysis of high affinity interactions using BIACORE

Both asymmetrical sensory blockade and dural puncture are undesirable outcomes of epidural analgesia. Identifying the epidural space with the needle bevel oriented parallel to the longitudinal axis of the patient's back limits the risk of headache in the event of dural puncture. However, rotating the bevel to direct a catheter cephalad may risk dural puncture. We prospectively studied the effects of needle rotation on the success of labor epidural analgesia and on the incidence of dural puncture. One hundred sixty ASA physical status I or II laboring parturients were randomly assigned to one of four groups. The epidural space was identified with the bevel of an 18-gauge Hustead needle directed to the patient's left. It was then rotated as follows: Group 0 = no rotation, final bevel orientation left (n = 39); Group 90 = rotation 90 degrees clockwise, bevel cephalad (n = 43); Group 180 = rotation 180 degrees clockwise, bevel right (n = 36); Group 270 = rotation 270 degrees clockwise, bevel caudad (n = 42). A single-orifice catheter was inserted 3 cm, and analgesia was induced in a standardized fashion. Dural puncture was evenly distributed among the groups (4.4%). There were more dermatomal segments blocked, fewer one-sided blocks, and more patients comfortable at 30 min with the needle bevel directed cephalad. Using a catheter inserted through a needle oriented in the cephalad direction increases the success of epidural analgesia. Implications: This prospective study shows that an epidural catheter inserted through a needle oriented in the cephalad direction increases the success of labor analgesia in the parturient. Carefully rotating the needle cephalad does not increase the risk of dural puncture, intravascular catheters, or failed blocks.     

The effect of prior dural puncture on cerebrospinal fluid sufentanil concentrations in sheep after the administration of epidural sufentanil

Sufentanil is a highly lipid soluble opioid that provides potent analgesia when administered in the subarachnoid space. Unfortunately, the penetration of sufentanil into the cerebrospinal fluid (CSF) after epidural administration is poor, and limits its effectiveness for epidural analgesia. Dural puncture may enhance the movement of epidural sufentanil into the subarachnoid space and increase its effectiveness. To determine whether the administration of epidural sufentanil adjacent to a dural puncture results in significantly greater CSF concentrations, 18 adult ewes were studied. Animals in the control group had an epidural catheter placed at the superior border of the pelvis without dural puncture. Animals in the study group had an epidural catheter placed, followed by a dural puncture performed using an 18-gauge Touhy needle. The dural puncture was performed one interspace cephalad to the epidural catheter. One hour after dural puncture, each animal received a loading dose of 0.35 microg/kg of sufentanil (5 microg/mL) through the epidural catheter, followed by an infusion of epidural sufentanil 0.15 microg x kg(-1) x h(-1) for a period of 4 h. After 4 h, CSF was sampled from a site one interspace caudad to the epidural catheter as well as at the cisterna magna. The mean CSF concentration of sufentanil at the level of the pelvis for animals with a dural puncture was 12.1 +/- 3.0 ng/mL compared with 1.8 ng/mL in controls with intact dura. Sufentanil concentrations at the cisterna magna were below the level of detection (0.08 ng/mL) for all animals in both groups. We conclude that an 18-gauge dural puncture significantly increases movement of sufentanil from the epidural to the intrathecal space. This increase in sufentanil concentration at the level of the pelvis was not associated with detectable levels of sufentanil at the brainstem. Implications: This study addresses the effect of dural puncture on spinal fluid concentrations of sufentanil after epidural administration. A sheep model was used to measure drug concentrations in the spinal fluid at the levels of the pelvis and brainstem after epidural administration. Dural puncture significantly enhanced movement of sufentanil into the spinal fluid at the level of the pelvis, but brainstem concentrations were below the level of detection. Analgesic concentrations of spinal sufentanil in the clinical setting, as well as brainstem concentrations associated with respiratory depression, have yet to be defined.     

Neurologic complications after placement of cerebrospinal fluid drainage catheters and needles in anesthetized patients: implications for regional anesthesia. Mayo Perioperative Outcomes Group

Subarachnoid or epidural needle placement in an anesthetized patient is controversial because general anesthesia and muscle relaxation may mask neural trauma. However, placement of a needle or catheter in the subarachnoid space for the purpose of cerebral spinal fluid (CSF) drainage is frequently performed in anesthetized patients undergoing neurosurgery. The records from 530 consecutive transsphenoidal surgeries performed with lumbar CSF drainage were reviewed to determine the types of neurologic complications attributable to spinal drainage and their rates of occurrence. All patients were anesthetized during CSF drain placement. A 19-gauge malleable needle was placed in 473 (89%) patients. Subarachnoid catheters (20- or 16-gauge catheters placed via 18- or 14-gauge epidural needles, respectively) were placed in 17 (3%) patients. In 40 (8%) patients, the type of drain was unspecified. No new neurologic deficits attributable to spinal drain insertion were detected in the immediate postoperative period or within 1 yr of surgery. Thirteen patients developed postdural puncture headache (2.5%, exact 95% confidence interval 1.3%-4.2%); seven required epidural blood patch (1.3%, 0.5%-2.7%). The low incidence (0%, 0.0%-0.7%) of neurologic injury from spinal drain insertion in anesthetized patients from this study is similar to the incidence of neurologic complications historically reported for both CSF drain insertion and spinal anesthesia. Implications: The performance of regional anesthesia in an anesthetized patient is controversial due to the possibility of unrecognized nerve injury. We report no cases of nerve injury caused by the placement of cerebrospinal fluid drainage needles and catheters in 530 anesthetized patients undergoing neurosurgery.     

Dural taps revisited. A 20-year survey from Birmingham Maternity Hospital

The records from 34,819 obstetric epidurals performed at Birmingham Maternity Hospital over the period 1969-1988 were examined. During that time there were 460 dural taps (overall incidence 1.3%). Of the methods used to detect the epidural space, loss of resistance to injection of saline was associated with the lowest incidence of dural tap (0.6%). The incidence of typical postdural puncture headache when managed conservatively was 86%. Provision of an epidural drip after delivery reduced the incidence of headache to 70%. Elective forceps delivery conferred no additional benefit, and tended to delay the onset of headache. Blood patches were performed on 135 patients and provided complete relief of headache in 93 (68%). A further 23 patients (16%) obtained partial relief.     

Epidural blood patch in a seven-year-old child

We present an unusual case of postoperative headache in a child after an epidural block. A seven-year-old girl (ASA 1) was scheduled to undergo a urological procedure under general anaesthesia combined with an epidural technique for intra- and postoperative analgesia. Although there was no evidence of dural puncture when the block was performed, the patient developed a headache postoperatively. The headache, which was accompanied by neck pain, appeared in the sitting or standing position and was relieved by decubitus. According to the mother, her child had never complained of those symptoms in the past. After independent evaluation by an anaesthetist and a neurologist, a postdural puncture headache (PDPH) was considered the most likely diagnosis. As oral analgesics failed to provide relief, and epidural blood patch (EBP) using 10 ml autologous blood was performed under light sedation. This was followed by resolution of the symptoms. Epidural injections of opioids and local anaesthetics are becoming increasingly popular for pain management in children. This implies that there may be an increasing number of unintentional dural punctures that may result in more PDPHs in children. Epidural blood patches are effective in treating PDPHs in adults but their use has been reported very rarely in children. Resolution of the patient's symptoms following EBP supported the diagnosis while illustrating that EBP can be useful in the treatment of PDPH in children.     

Insertion characteristics and complications of a new spinal needle 26-gauge Atraucan

We evaluated the insertion characteristics and complications of a new spinal needle 26-gauge Atraucan (group A) compared with 27-gauge Whitacre (group W) in 100 patients undergoing orthopedic surgeries of the lower extremities. Spinal anesthesia was performed in the lateral decubitus position and 0.40-0.5% tetracaine 1.6-2.5 ml was injected through the L 3/4 or L 4/5 interspace. The tactile appreciation of dural presentation with the needle (dural click) was higher in group W (89.8%) than in group A (42.6%) which the back flow of cerebrospinal fluid was not recognized within three punctures was in 2 cases (4%) in group A and in 1 case (2%) in group W. In these 3 cases, spinal anesthesia was performed easily using 25-gauge Whitacre. In group A, the spinal needle could be inserted without using an introducer in 35 cases (70%). The incidence of the postoperative headache or back pain was low and postdural puncture headache (PDPH) did not occur in both groups. We conclude that 26-gauge Atraucan can be handled easily and useful for preventing PDPH.     

Method of evaluation "MMexico" in emergency medicine

An 11-year-old boy suffered an inadvertent dural puncture during placement of an epidural catheter for postoperative analgesia. He developed symptoms of mild headache only, but severe and protracted orthostatic nausea and dizziness, which eventually resolved completely following epidural blood patch. His symptoms were atypical and could have been misinterpreted in the context of dural puncture for diagnosis, or for administration of intrathecal chemotherapy. The reported incidence of headache following dural puncture in children is low. It may be that the manifestations are different from those of adults and that the true incidence of symptoms related to leakage of cerebrospinal fluid is higher in children than currently recognised.     

Atraucan: a new needle for spinal anesthesia

BACKGROUND AND OBJECTIVES: Atraucan 26-gauge spinal needles have a tip designed to make a small linear cut (as opposed to a V-shaped cut) in the dura mater. The cut is shorter than the outside diameter of the needle and is dilated as the needle passes through the dura. The needle is used with a 20-gauge introducer. In vitro, it causes less leakage of cerebrospinal fluid than Quincke 26-gauge or Sprotte 24-gauge needles. This study was designed to test the ease of use and any damage caused to the needle tip during lumbar dural puncture. METHODS: This was a multicenter trial (six centers in five countries) involving 362 patients undergoing spinal anesthesia. A detailed questionnaire was filled in for every patient by the anesthesiologist. All the needles were returned to the factory and examined microscopically for damage. RESULTS: Lumbar dural puncture was successful in all but one patient. Spinal anesthesia was satisfactory for the planned surgery in 97%. Microscopy of the needle tips showed only a minor degree (0.01-0.19 mm) of bending in 14%, and none of the tips had a "hook." Postdural puncture headache (PDPH) occurred in nine patients (2.5%), all but one of whom (a 15-year-old male) were females under 55 years of age. CONCLUSIONS: The Atraucan needle is easy to use and has a high success rate in identifying the subarachnoid space. Lumbar dural puncture causes minimal damage to the tip. The incidence of PDPH is low, but a larger comparative study needs to be performed.     

A case with sarcomatoid hepatocellular carcinoma

BACKGROUND AND OBJECTIVES: The goal of the present investigation was to compare the double-segment and the needle-through-needle techniques for combined spinal and epidural anesthesia (CSE) in a prospective, randomized, blinded study. METHODS: With Ethical Committee approval and patient's consent, 120 patients were randomized to receive CSE by the needle-through-needle (SST; n=60) or the double-segment technique (DST; n=60). A blind observer measured the time required from skin disinfection to readiness for surgery (loss of pinprick sensation up to T10), failure of dural puncture, need for epidural top-up before surgery, patient acceptance, and occurrence of complications. RESULTS: No neurologic complications were observed in either group. Time to readiness for surgery was 22.7+/-8.2 minutes in the SST group and 29.8+/-8.31 minutes in the DST one (P < .001). Dural puncture was unsuccessful in three patients in the SST group (5%) and in one patient in the DST group (1.6%) (ns); inadequate spread of spinal anesthesia was observed in five patients in the SST group (8.3%) and in eight patients in the DST group (13.3%) (ns). No difference in the incidence of hypotension, postdural puncture headache, and back pain was observed between the two groups. Acceptance of anesthetic procedure was better in the SST (85%) than in the DST group (66.6%) (P < .05). CONCLUSIONS: The needle-through-needle technique for CSE requires less time, has no greater failure rate, and results in greater patient satisfaction than the double-segment technique. The use of a spinal needle with an adjustable locking mechanism and protruding up to 15 mm beyond the Tuohy needle improved successful spinal block in the needle-through-needle technique compared with previous reports.     

The epidural blood patch--current practices and concerns

Post dural puncture headache is a common sequelae of spinal and, sometimes, epidural anesthesia. Since 1960, the practice of placing autologous blood into the epidural space to treat spinal headache has been used with great success. The blood patch can provide immediate symptom relief from spinal headache and repair of the CSF leak, which is the basic mechanism of post dural puncture headache. Discrepancies exist in the literature and in today's common practice regarding technique and timing for this treatment. This is a procedure not without complications and requires caution. Contained herein are recommendations for safe and effective use of the epidural blood patch. Following these procedures, anesthetists will likely see an 85% to 98% immediate cure rate for post dural puncture headache with the fewest possible complications.     

Postmyelography headache: a review

The author reviews the topic of postdural puncture headache (PDPH) so radiologists can better understand, prevent, and treat this common complication of myelography. PDPH, a postural headache relieved by lying supine, occurs after 36.0%-58.2% of myelographic procedures performed with 22-gauge Quincke needles. It begins within 3 days and lasts 3-5 days. Thin, young women are more likely to develop PDPH. Smaller gauge needles, blunt-tip needles, a paramedian approach, and parallel orientation of a bevel needle are associated with lower PDPH rates. Intravenous hydration, no removal of cerebrospinal fluid, experience of the myelographer, and inpatient status have been inconsistently associated with lower PDPH rates. Treatment is supportive with bed rest. Oral or intravenous methylxanthine agents may be given for more severe PDPH. An epidural blood patch, although rarely needed, is very effective.     

Epidural analgesia during labor

Epidural analgesia is a commonly employed technique of providing pain relief during labor. The number of parturients given intrapartum epidural analgesia is reported to be over 50 percent at many institutions in the United States. The procedure has few contraindications, the primary ones being patient refusal, maternal hemorrhage and coagulopathy. Induction of epidural analgesia in early labor remains controversial. However, many physicians induce analgesia as soon as the diagnosis of active labor has been established and the patient has requested pain relief. The most common complications occurring with epidural analgesia are maternal hypotension and postdural puncture headache. Retrospective studies have demonstrated an association between epidural analgesia and increases in duration of labor, instrumental vaginal delivery and cesarean section for labor. However, several recent prospective studies have concluded that epidural analgesia does not adversely affect the progress of labor or increase the rate of cesarean section. These remain controversial issues among practicing physicians.     

Aetiology of oral cancer: alcohol

This prospective cohort study determined the incidence and risk factors for development of postdural puncture headache (PDPH) in children after lumbar puncture (LP). Eighty-six children were enrolled. LPs were performed with use of 22-gauge spinal needles with the bevel oriented parallel to the long axis of the spine. Follow-up telephone interviews and patients' diary of symptoms were collected. Headache brought on by sitting up and relieved by lying down was defined as PDPH. Of the 80 who completed the study, six (8%) developed PDPH. Two (3%) were less than 6 years old and four (5%) were 6 to 12 years of age. Children with a history of headache following a previous LP were nine times as likely to experience PDPH. PDPH occurs not infrequently in children. A prior history of headache is a predisposing factor.     

General convulsive crisis related to pneumocephalus after inadvertant dural puncture in an obstetric patient]

We report a case of iatrogenic pneumocephalus in an obstetric patient after accidental dural puncture during repeated attempts to locate the epidural space by the technique of loss-of-resistance to air. Analgesia was provided throughout labor. Two days after puncture, typical spinal headache developed and was treated with bed rest, oral analgesics and hydration. The patient was released four days after delivery but returned to the hospital emergency service after suffering general convulsions and loss of consciousness which resolved spontaneously. A computerized tomography (CT) scan revealed pneumocephalus, to which the convulsions were attributed. No further convulsions occurred in spite of the fact that anticonvulsives were not prescribed. A CT scan one month later was normal.     

The impact of occupation on self-reported cardiovascular morbidity in western Germany: gender differences

Two hundred one consecutive patients with cancer pain who received intrathecal pain treatment between 1985 and 1993 were included in this retrospective study undertaken to test the hypothesis that epidural metastasis is a common cause of "refractory" cancer pain and that its presence may affect the efficacy and the complication rates of intraspinal pain treatment. Fifty-seven (approximately 28%) patients were investigated by metrizamide myelography, computerized tomography (CT), magnetic resonance imaging (MRI), laminectomy, or neurohistopathology. Epidural metastases were found in 40 (70%) and spinal stenosis in 33 (approximately 58%); 7 patients with total and 26 with partial occlusion of the spinal canal. Presence of epidural metastasis affected catheter insertion complications, daily dosages, and complications of the intrathecal pain treatment only when it was associated with spinal canal stenosis (partial or total). During the period of the intrathecal treatment, the patients with confirmed epidural metastasis and total spinal canal stenosis needed significantly (P < 0.05) higher daily doses of opioid (means = 77 +/- 103 versus 22 +/- 29 mg) and intrathecal bupivacaine (means = 65 +/- 44 versus 33 +/- 20 mg) and had significantly (P < 0.05) higher rates (14% versus 0%) of radicular pain at injection and poor distribution of analgesia than those without epidural metastasis and spinal canal stenosis. In contrast, the rate of occurrence of post-dural puncture headache was significantly (P < 0.05) lower in patients with partial (4%) and total (14%) spinal stenosis than in those without (29%). Unexpected paraplegia occurred in four patients and was due to accidental injury during attempted dural puncture (N = 1) and collapse (due to cerebrospinal fluid leakage leading to "medullary coning" of an unknown epidural metastasis (N = 3).     

Pituitary apoplexy after spinal anaesthesia

We report the case of a previously healthy 51-yr-old male who underwent an uneventful total hip replacement under spinal anaesthesia. His immediate postoperative course was complicated by the development of a severe frontal headache. Initial conservative treatment included oral analgesics and an epidural blood patch. The headache persisted and was followed by progressive vision loss and a right partial third nerve palsy. The patient was almost blind at the time of transfer to our neurosurgical unit. Relevant investigations revealed marked hyponatraemia (serum sodium concentration 122 mmol litre-1) and second-degree heart block (Mobitz I). A CT scan showed a pituitary tumour and confirmed the clinical diagnosis of pituitary apoplexy. Urgent craniotomy was scheduled and a large necrotic pituitary adenoma was excised. The postoperative course was uneventful with return of near normal vision at the time of discharge. Clinicians should consider this diagnosis when focal neurological deficits occur with post-dural puncture headache.     

Significant reduction in post-lumbar puncture headache using an atraumatic needle. A double-blind, controlled clinical trial

A characteristic headache occurs in about 36-55% of patients after lumbar puncture, and many of these patients need bed rest for one or more days to get relief. In a double-blind randomized trial we compared a new 22-gauge atraumatic puncture needle with the most widely used 20-gauge "conventional" needle. In 49 patients randomized to the atraumatic needle, post-lumbar puncture headache occurred in 6%, whereas in the 50 patients randomized to the conventional needle this occurred in 32% (p = 0.001). On the basis of these results we recommend use of the atraumatic needle in order to diminish the frequency of post-lumbar puncture headache.     

Epiduritis after long-term pain therapy with an epidural catheter--review of the literature with a current case report

Patients suffering from vascular disease are often a challenge for the acute pain service. Ischaemia, impaired wound healing, stump and phantom limb pain often require a complex analgesic regimen. Invasive measures such as spinal or epidural catheters can be very helpful but carry the risk of infection, as shown by this case report. A 53-year-old woman with a ten-year history of diabetes developed arterial vascular disease. Her right lower leg had been amputated two years previously. She was now admitted with necroses of the left forefoot. A bypass operation was performed under general anaesthesia. Because of intractable ischaemic pain, she was provided with an epidural catheter by the acute pain service. The bypass occluded, however, and a few days later her left lower leg also had to be amputated, this operation being performed under epidural anaesthesia with bupivacaine. The catheter was subsequently used for postoperative pain control and as a means to prevent phantom limb pain. When signs of superficial catheter infection were noticed days later, the catheter was immediately removed. Intractable pain then developed in the left leg which could not be sufficiently controlled with opioids and NSAIDs, and so a second epidural catheter was inserted one segment rostrally. Several days later the infected vascular prosthesis had to be removed followed by amputation of the thigh, this operation also being performed in epidural anaesthesia. Eleven days after insertion of the first epidural catheter, the patient complained of low back pain and headache. Examination by a neurologist revealed no signs of intraspinal infection. The second epidural catheter dislocated at this point in time and it was decided to introduce a third one, this being the only means to treat the otherwise intractable stump pain. Ten days later meningism, Kernig's sign and leucocytosis developed. NMR tomography detected intraspinal fluid in the epidural space at the dorsal border of the spinal canal. A hemilaminectomy was performed. The spinal epidural space showed signs of inflammation of the adipose tissue, but no pus. A little necrotic material and residues of an old haematoma were removed and the epidural space was lavaged. Specimens taken from the epidural material revealed colonisation with staphylococcus epidermidis, which was sensitive to the broad spectrum antibiotics formerly given to the patient to treat the infection in the left stump. By the next day, all signs of epiduritis had disappeared and the patient recovered completely.     

Oral anticoagulant prophylaxis and epidural catheter removal

BACKGROUND AND OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.     

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BACKGROUND AND OBJECTIVES: A 38-year-old woman presented with severe intractable pain in the sacral and perirectal areas secondary to metastatic stage I.B. squamous cell carcinoma of the cervix. METHODS: An indwelling epidural catheter was placed to control the patient's symptoms after failure of conservative therapies. Finally, an infusion containing isobaric 0.2% ropivacaine with 0.002% preservative-free morphine and 0.0002% epinephrine was started to treat her pain and preserve motor function to preserve quality of life. RESULTS: The patient obtained good pain relief with this regimen and was discharged home. She was able to walk with assistance and maintain good quality of life until her death approximately 7 weeks after the placement of the indwelling epidural catheter. CONCLUSION: The use of ropivacaine in combination with other analgesics, via an intrathecal catheter for patient-controlled analgesia, was an effective treatment for this patient. In the future, ropivacaine administered epidurally or intrathecally alone, or in combination with other analgesics, may become the local anesthetic of choice due to its preservation of motor function. Certainly, further scientific studies are indicated in the cancer patient population.