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Clinical Studies 

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Longer Needle More Effective at Obtaining CSF For Combined Spinal Epidural Analgesia


Dr. Catherine L. Hamilton


In a recent study, the Sprotte needle was associated with a significantly higher failure rate (17%) for obtaining cerebrospinal fluid (CSF) during combined spinal epidural analgesia for labor and delivery; this finding comes from a comparison with the longer Gertie Marx needle, which had a 100% success rate in obtaining CSF. The Sprotte needle is 9 mm in length beyond the top of the Tuohy needle with the hubs engaged; the Gertie Marx needle extends 17 mm beyond the tip of the Tuohy needle.


“The shorter needle is clearly inadequate for many patients,” noted Dr. Catherine L. Hamilton, Fellow in Obstetrical Anesthesia, Department of Anesthesia, Stanford University School of Medicine, California.


When CSF could not be obtained with the Sprotte needle, patients were switched to the Gertie Marx needle in order to use the combined spinal epidural technique, Dr. Hamilton explained. In those patients, 83% developed a post-dural puncture headache.


“Even though we failed to obtain CSF with the Sprotte needle, we may have punctured the dura,” she observed.


“Based on this study, we would recommend that if the needle does not obtain CSF for a combined spinal epidural needle technique, don’t try with another needle because there may be an occult dural puncture and that patient may be at increased risk for a spinal headache,” Dr. Hamilton cautioned.


The present study was prompted by a high failure rate with an intrathecal sufentanil technique in a previous study undertaken by the same group. In the previous study, CSF was not obtained in 7% of cases; and in another 7% or 8%, CSF was obtained and sufentanil was injected, but the patients did not gain any pain relief.


“This high failure prompted us to suspect that the Sprotte needle was too short or that it deviated from the midline. We hypothesized that it was the length of the needle,” explained Dr. Hamilton.


A randomized, double-blind, pros-pective trial comparing the Sprotte needle with the Gertie Marx needle was undertaken in 73 laboring women. The study evaluated success at obtaining CSF, adequacy of analgesia achieved using the combined spinal epidural technique and the occurrence of postdural headaches.


The procedure was performed with either of the two needles using a midline approach at L2-3 or L3-4 with the patient sitting. If no CSF was obtained, the alternate needle was tried. After obtaining CSF, sufentanil 10 µg, diluted in saline, was injected. An epidural catheter was threaded but not used until the patient requested more pain relief.


“Results confirmed our hypothesis that the shorter needle was associated with a higher failure rate,” said Dr. Hamilton. Failure to obtain CSF occurred in six patients in the Sprotte needle group versus none in the Gertie Marx group. In all the failures, the Gertie Marx needle was subsequently successful in obtaining CSF. Seven patients requested additional analgesia within 30 minutes (three in the Sprotte group, and four in the Gertie Marx group). “These seven analgesic failures were not all explained on the basis of rapid labor,” she noted. Although 12 patients developed postdural puncture headaches, there were too few patients to draw conclusions regarding the relative incidence of headache with the two needles, she said. Six patients received epidural blood patches.


“We are now using a Gertie Marx needle for laboring patients who request combined spinal epidural analgesia,” concluded Dr. Hamilton.


Sheila Cohen, MB, ChB, was senior author of this paper; others associated with the study were Drs. E.T. Riley and E.F. Ratner.


A Comparison of Complications Which Occur Following Combined Spinal-Epidural or Continuous Infusion Lumbar Epidural Analgesia for Labor


Ramasamy M, Birnbach DJ, Stein DJ, Bourlier RA, Danzer BI,




Epidural and combined spinal epidural (CSE) techniques are both being used to provide maternal analgesia during labor. Since combined spinal-epidural analgesia for labor is a relatively new technique, there are few studies which have evaluated its complications. We retrospectively reviewed all cases of CSE and epidural analgesia for labor at our institution during a six- month period, to compare the safety and efficacy of these two currently used techniques.




A retrospective review of all charts of patients who received labor analgesia during the six month period from July 1994-January 1995 was completed. Each chart was evaluated for the following complications at any time between initiation of the block and discharge from the labor and delivery suite: failed block, fetal distress within 15 minutes of initiation of the block, inadequate block when attempt was made to bring up level for cesarean section, total spinal, inability to phonate, inability to swallow, headache, intrathecal placement of catheter, intravascular placement of catheter, or use of less local anesthetic than expected to achieve a block when dosing for cesarean section. Data were analyzed by chi-square testing.




A total of 752 patients requested epidural analgesia during the study period. Of these patients, 296 (39%) received epidural analgesia and 456 (61%) received CSE. Labor epidurals were initially dosed with 0.25% bupivacaine, followed by an infusion of 0.125% bupivacaine plus fentanyl. CSE was performed with a standard epidural needle and 26g Gertie Marx needle® (IMD, Utah), with subarachnoid administration of 10 mcg of sufentanil.
Of the parameters examined, there was a statistically significant difference between groups only in regards to wet taps and higher than anticipated blocks. Statistically fewer patients in the CSE group experienced accidental dural punctures and more patients in the CSE group had a T4 block after administration of less than 12 ml of local anesthetic.




Our data suggests that CSE is as safe as epidural anesthesia for pain relief in laboring patients. There were no major complications and minor complications, other than pruritis, were not statistically different between epidural and CSE groups. CSE may be protective against accidental dural punctures by allowing an extra method of verification of needle location. Since less local anesthetic may be required to provide a T4 block in CSE patients, caution is necessary when supplementing the epidural catheter for an operative delivery if CSE has been performed.


















Comparison of cutting and pencil-point spinal needle in spinal anesthesia regarding postdural puncture headache A meta-analysis


Hong Xu, MD, Yang Liu, MD, WenYe song, MD, ShunLi Kan, MD, FeiFei Liu, MD, Di Zhang, MD




Current evidences suggest that the pencil-point spinal needle was significantly superior compared with cutting spinal needle regarding the frequency of PDPH, PDPH severity, and the use of EBP. In view of this, we recommend the use of pencil-point spinal needle in spinal anesthesia and lumbar puncture.

Apart from the spinal needle size, spinal needle shape might be the most important modifiable risk factors of PDPH. And we consider pencil-point spinal needle another effective way to reduce the incidence of PDPH in spinal anesthesia and lumbar puncture.




Atraumatic lumbar puncture needles after all these years, are we still missing the point?


Katherine Arendt, Bart M Demaerschalk, Dean Marko Wingerchuk, William Camann




Modern cutting needles, also called Quincke needles, have an obliquely sliced tip that cuts through the dura. The pencil-point or atraumatic needle was thought to penetrate and then separate the dural fibers, resulting in a less traumatic hole and subsequent less loss of CSF and a lower incidence of PDPH.

The rate of PDPH for diagnostic lumbar puncture in an ambulatory population with a 20- or 22-gauge cutting needle is estimated to be 36%. In comparison, the rate of PDPH with a 22-gauge atraumatic needle is estimated to be less than 2%. The superiority of the atraumatic needle has also been demonstrated in a randomized trial for myelography, with fewer postmyelogram headaches observed with an atraumatic needle compared with a cutting tip design.




The evidence that atraumatic spinal needles cause fewer PDPHs is so convincing that both the American Society of Anesthesiologists (ASA) and the American Academy of Neurology have published statements encouraging the replacement of cutting needles by atraumatic spinal needles.

Expressed differently, this evidence reveals that for every 6 neurology patients that undergo a diagnostic dural puncture with an atraumatic needle instead of a standard needle, 1 patient will get a headache.

Further, studies looking specifically at neurology patients undergoing lumbar puncture have shown a decrease from 36% to ~3%.

The use of non cutting or pencil-point spinal needles should become the standard for performing diagnostic lumbar puncture.



Use of atraumatic spinal needles among neurologists in the United States.


Birnbach DJ, Kuroda MM, Sternman D, Thys DM.




Atraumatic spinal needles for lumbar puncture have been shown to dramatically decrease the risk of postdural puncture headache. Although the use of these needles is standard practice among anesthesiologists, they have not been adopted by other medical specialties. This may lead to unnecessary morbidity among patients undergoing lumbar puncture.




Postdural Puncture Headache (PDPH)

Michael C. Plewa; Scott C. Dulebohn




Postdural puncture headache (PDPH) is a potential expected complication of a lumbar puncture Incidence has been estimated quite variable in the literature, but may be approximately 10% to 40% of LP procedures, but can be as low as 2% when small gauge (less than or equal to 24 gauge) non-cutting needles are used.




There is room for improvement in the prevention and treatment of headache after lumbar puncture.


Stendell L, Fomsgaard JS, Olsen KS



The incidence of post dural puncture headache (PDPH) after lumbar puncture (LP) can be reduced from 36% to 0-9% by the use of an atraumatic needle size 24 gauge (G)/0.56 mm rather than a traumatic needle size 22 G/0.7 mm.

Longer Needle
A Comparison
Comparison Of Cutting
Atraumatic Lumbar
Use of Atraumatic
There is Room
Evalution of 25g Quincke

Evaluation of 25-gauge Quincke and 24-gauge Gertie Marx needles for spinal anaesthesia for caesarean section


Charles ImarengiayeN. Edomwony



Sixty women were studied. The 24-gauge Gertie Marx needle resulted in more successful location of the spinal space on the second attempt (P<0.05). Non-postdural puncture headache was seen in 43% of the study population. PDPH was seen in 10% of the Quincke group and none in the Gertie Marx group. There was no difference in the incidence of backache in both groups.



The ease of insertion and low incidence of PDPH with the Gertie Marx needle may encourage trainee anaesthetists to use this needle for caesarean section.

Combined Spinal-Epidural Anesthesia

J. Sudharma Ranasinghe, Elyad Davidson, and David J. Birnbach



The CSE technique is well-established method for various types of surgery, particularly in obstetrics. In our institution, the CSE technique is the most commonly performed regional technique for labor analgesia (97%) as well as cesarean delivery (54%). CSE offers many advantages; it provides a method to administer neuraxial anesthesia and analgesia in numerous clinical situations.

The CSE technique offers the advantages of both spinal and epidural techniques and therefore has a high success rate in providing regional anesthesia. CSE provides rapid onset and the ability to titrate to a desired sensory level, control the duration of the block, and deliver postoperative analgesia. Another advantage of CSE is the facilitation of the spinal needle entrance into the subarachnoid space. The Tuohy needle serves as a guide for the spinal needle almost to the subarachnoid space. This allows for use of the smaller-gauge atraumatic spinal needles, with which the PDPH is absent or rare.

CSE Anesthesia
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