Hearing loss does not occur in young patients undergoing spinal anesthesia

BACKGROUND AND OBJECTIVES: Although uncommon, hearing loss after spinal anesthesia has been described. Vestibulocochlear dysfunction after spinal anesthesia in which 22-gauge and 25-gauge Quincke needles were used was investigated to determine if needle size affected hearing. METHODS: Patients with American Society of Anesthesiologists physical status I and II, aged 20 to 40 years, who were undergoing lower extremity surgery under spinal anesthesia were randomized into 2 groups. After intravenous hydration, 3 mL of 0.5% bupivacaine was administered for spinal anesthesia, which was performed with a 22-gauge Quincke needle in group I (n=30) patients and a 25-gauge Quincke needle in group II (n=30) patients. Before surgery and 2 days after surgery, pure-tone audiometry and tympanometry were performed. Preoperative and postoperative hearing data were obtained in the right and left ears for every frequency. Headache, nausea, and vomiting and cranial nerve III, IV, V, VI, VII, and VIII function were assessed on postoperative day 2. RESULTS: Demographic data were not different between the groups. No hypoacousis was noted at any frequency during the entire testing period in either group. Two patients from group I experienced postdural puncture headache on postoperative day 3, and neither had hearing loss. No patient had cranial nerve dysfunction. CONCLUSIONS: We were unable to induce hearing loss in young patients undergoing spinal anesthesia by injecting the anesthetic with a 22-gauge or a 25-gauge Quincke needle.     

Auditory function following spinal analgesia. Comparison of two spinal needles

BACKGROUND AND OBJECTIVE: Auditory impairment is among the lesser known complications of spinal analgesia. The aim of the present study was to determine the degree of vestibulocochlear dysfunction in patients undergoing spinal analgesia for lower abdominal surgery. METHODS: Eighty patients who had received spinal analgesia for lower abdominal surgery were studied. Males were undergoing inguinal herniorraphy and the females tubectomy. Audiograms were performed before operation and on the second and seventh postoperative days. Hearing levels were measured from 250 Hz-8 kHz. In Group 1 (n = 40) a 22-gauge, cutting type of spinal needle (Howard Jones) was used. In Group 2 (n = 40) a 25-gauge, non-cutting spinal needle (Whitacre) was used. RESULTS: Hearing loss >10 dB was noticed in three patients in Group 1 and none in Group 2. The mean hearing level was more reduced in Group 1 patients. CONCLUSIONS: Use of cutting type spinal needle is associated with a greater decrease in mean hearing levels compared to the non-cutting type.     

Headache after spinal anesthesia for cesarean section: a comparison of the 27-gauge Quincke and 24-gauge Sprotte needles.

A high incidence of postdural puncture headache (PDPH) occurs after spinal anesthesia for cesarean section. To examine this problem, a study was conducted with the recently developed 24-gauge Sprotte and 27-gauge Quincke needles in patients undergoing elective and emergency cesarean section (n = 298). The needle to be used was assigned in a random manner: group I, 27-gauge Quincke (n = 147); group II, 24-gauge Sprotte (n = 151). During the postoperative period, patients were visited daily and asked specifically about the presence and severity of headache. The overall incidence of PDPH was 2% (n = 6), five in the Quincke group (3.5%) and one in the Sprotte group (0.7%). There was no significant difference in the incidence of PDPH between the two groups. Five headaches were classified as mild, and only one was moderate to severe. All headaches resolved quickly with conservative management and without blood patch. The authors conclude that the choice between a 27-gauge Quincke and a 24-gauge Sprotte needle does not influence the incidence of PDPH after spinal anesthesia for cesarean section.     

Role of repeated epidural injections in preventing post-spinal hearing loss

Study ObjectiveTo determine if epidural volume extension and continued postoperative epidural injections prevent hearing loss associated with a 23-gauge (G) Quincke spinal needle.DesignProspective, double blinded trial.SettingOperating rooms.Patients30 adult patients scheduled for lower abdominal or perineal surgery during spinal anesthesia.InterventionsPatients were divided into two groups of 15 each. All patients received subarachnoid injection with a 23-G Quincke needle. While patients in Group S received a single-shot spinal, Group E patients underwent epidural catheter placement one intervertebral space above. The epidural catheter was bolused with 10 mL of normal saline followed by postoperative epidural boluses of local anesthetic for analgesia as needed.MeasurementsPatients’ auditory function was evaluated by pure tone audiometry (frequencies of 250-8,000 Hz) on the day before and two days after receiving the spinal anesthesia.Main ResultsUnilateral low-frequency hearing loss (500 Hz) was seen in Group S (P < 0.05). It was prevented by the repeated epidural injections as used in Group E.ConclusionFollowing spinal anesthesia, epidural volume extension with 10 mL of normal saline followed by epidural local anesthetic boluses titrated to adequate postoperative analgesia (6-8 mL each time) prevents post-spinal hearing loss.     

Does spinal anesthesia cause hearing loss in the obstetric population?

Lumbar puncture is believed to cause hypoacousis by causing cerebrospinal fluid leakage in older individuals. We hypothesized that parturients undergoing subarachnoid block (SAB) may experience hearing loss. We evaluated the effects of SAB on hearing in parturients undergoing elective cesarean delivery. We also compared two types of spinal needles: a pencil-point needle (24-gauge Sprotte needle) and a cutting needle (25-gauge Quincke needle). Sixty patients were studied: 20 received lumbar epidural block for labor analgesia (controls), 20 received a SAB with a Sprotte needle, and 20 others received a SAB with a Quincke needle for cesarean delivery. A tone audiometer was used to test for that decibel level at which the patient heard 125-, 250-, 500-, 1000-, 2000-, 4000-, and 8000-Hz frequencies. The hearing test was performed before anesthesia, after delivery, and on the first and second postoperative days. The results were analyzed by using repeated-measures analysis of variance at P < 0.05. No patient from any of the three groups developed a hearing loss either at low or high frequencies. Spinal anesthesia does not lead to significant hearing loss when a pencil- or a cutting-point needle is used in the obstetric population. IMPLICATIONS: Sixty obstetric patients were enrolled in the study to examine the possible effects of spinal anesthesia on their hearing. By using an audiometer, the patient's hearing was evaluated before delivery, after delivery, and for the following 2 days. There was no significant change of hearing in any of the patients.     

Whitacre 22-gauge pencil-point needle for spinal anaesthesia. A controlled trial in 300 young orthopaedic patients.

In a prospective study of 300 young orthopaedic in-patients (less than 40 years) given spinal anaesthesia through a 22-gauge Whitacre (n = 150) or a 25-gauge Quincke spinal needle (n = 150), we found a 5.3% and a 9.3% incidence of post-spinal headache (PSH) respectively. Females (10.6%) had a higher overall incidence of post-spinal headache than males (5.6%) with more than twice as many females being affected in the 25 than in the 22-gauge group (14.5% vs 6.1%). The average duration of post-spinal headache was less in the 22-gauge group (36 h vs 42.4 h) as was the incidence of severe headache. It is concluded that the Whitacre 22-gauge needle is more suited for spinal analgesia in young female patients due to its ease of handling and its lower incidence of post-spinal headache.     

Influence on hearing of 22 G Whitacre and 22 G Quincke needles

Audiograms were performed pre-operatively and 2 days postoperatively in 48 patients given spinal anaesthesia for transurethral resection of the prostate. Hearing levels were examined at 1000 Hz and below. Either 22 G standard design (Quincke) needles (n = 25) or 22 G pencil-point design (Whitacre) needles (n = 23) were used. Hearing loss of 10 dB or more at two or more frequencies were observed in six of 25 patients in the Quincke group and in two of 23 patients in the Whitacre group. The mean hearing level was more reduced in the Quincke group. The shape of the tip of the spinal needle seems to be of some importance to the effects on hearing level that may occur after spinal anaesthesia.     

Postdural puncture headache: a randomized comparison of five spinal needles in obstetric patients

This prospective, blinded, randomized study compares the incidence of postdural puncture headache (PDPH) and the epidural blood patch (EBP) rate for five spinal needles when used in obstetric patients. One thousand two women undergoing elective cesarean delivery under spinal anesthesia were recruited. We used two cutting needles: 26-gauge Atraucan and 25-gauge Quincke, and three pencil-point needles: 24-gauge Gertie Marx (GM), 24-gauge Sprotte, and 25-gauge Whitacre. The needle for each weekday was chosen randomly. Cutting needles were inserted parallel to the dural fibers. The incidences of PDPH were, respectively, 5%, 8.7%, 4%, 2.8%, and 3.1% for Atraucan, Quincke, GM, Sprotte, and Whitacre needles (P = 0.04, chi(2) analysis), and the corresponding EBP rates in those with PDPH were 55%, 66%, 12.5%, 0%, and 0% (P = 0.000). The Quincke needle had a more frequent PDPH rate than the Sprotte or the Whitacre needle (P = 0.02) and a more frequent EBP rate than the GM, Sprotte, or the Whitacre needle (P = 0.01). The Atraucan needle had a more frequent EBP rate than the Sprotte or Whitacre needle (P = 0.05). Neither the PDPH rate nor the EBP rates differed among the pencil-point needles. The cost of EBP must be taken into consideration when choosing a spinal needle. We conclude that pencil-point spinal needles should be used for subarachnoid anesthesia in obstetric patients.     

Die Bedeutung von Nadeltyp und Immobilisation für den postspinalen Kopfschmerz

Post-dural puncture headache (PDPH) is a significant complication of spinal anaesthesia. Diameter and tip of the needle as well as the patient′s age have been proven to be important determinants. The question of whether post-operative recumbency can reduce the risk of PDPH has not been answered uniformly. And besides, some studies referring to this subject reveal methodical failures, for example, as to clear definition and exact documentation of post-operative immobilization. Furthermore, fine-gauge needles (26G or more) have not been investigated yet. The first aim of our study was therefore to examine the role of recumbency in the prevention of PDPH under controlled conditions using thin needles. Secondly, we wanted to confirm the reported prophylactic effect of needles with a modified, atraumatic tip (Whitacre and Atraucan) by comparing them to Quincke needles of identical diameter. Most of the former investigators compared Quincke with atraumatic needles of different size regardless of the known influence of the diameter on PDPH. Patients and methods: In a prospective study we included 481 consecutive patients undergoing a total of 500 orthopaedic operations under spinal anaesthesia. The latter was performed in a standardized manner (patient sitting, midline approach, needle with parallel bevel direction), using four different needles allocated randomly (26-gauge and 27-gauge needles with Quincke tip, 26-gauge Atraucan and 27-gauge Whitacre cannula). Half of the patients were instructed to stay in bed for 24 h (horizontal position without raising head), the others to get up as early as possible. An anaesthesiologist visited the patients on the fourth postoperative day or later and questioned them about headache and duration of recumbency. Additionally, the patients had to fill out a questionnaire 1 week after surgery. Any postural headache was considered as PDPH. Results: The four groups of different needles had homogeneous demographic characteristics (see Table 1). A total of 47 patients (9.4%) developed PDPH. The incidence was highest after puncture with a 26-gauge Quincke cannula (17.6%) with a significant difference compared to the other needles (see Table 2). PDPH incidence correlated well with increasing age and number of dural punctures, but showed no relation to sex, patient´s history of headache or experience of the anaesthesiologist. Only about half of the patients (60.5%) followed the instructions regarding mobilization or recumbency. The duration of strict bed rest did not influence the development of PDPH: The overall incidence was 9.4% in the recumbency group and 8.8% in the group of early ambulation. In all, 45 patients suffered from ordinary not posture-related headache. Conclusions: The significantly higher incidence of PDPH after spinal anaesthesia with 26-gauge Quincke needles compared to the 27-gauge Quincke and the 26-gauge Atraucan group confirmed the importance of both needle diameter and design of its tip. The Atraucan cannula has not been examined in a controlled study (in comparison with Quincke needle of the same diameter) before. In accordance with other investigators we found patient′s age and number of puncture attempts as additional predictors of PDPH. Consequent bed rest, however, was not able to reduce its incidence. Our studies reveal the poor compliance of patients with regard to mobilization/immobilization, a problem which possibly has not been considered enough in former studies examining the influence of bed rest on PDPH. Based on the literature and the present findings, we recommend using thin needles with atraumatic tips for spinal anaesthesia if possible. Recumbency presents an avoidable stress for patients as well as medical staff and should no longer be ordered.     

Post dural puncture headache in obstetric patients: experience from a West African teaching hospital

BACKGROUND: This prospective, non-randomised study examined the frequency and severity of post dural puncture headache in 96 Ghanaian women who consented to spinal anaesthesia for caesarean section at the Korle Bu Teaching Hospital, Accra, Ghana. METHOD: Spinal anaesthesia was performed using 22-gauge (n = 22), 25-gauge (n = 46) or 26-gauge (n = 38) Quincke needles. Patients were followed up to determine the incidence and severity of post spinal headache. RESULT: The overall incidence of post dural puncture headache was 8.3%, but was significantly higher (33%) in patients in whom 22-gauge Quincke needles were used than in the other two groups (4% and 5% respectively: P = 0.003). Most patients rated their headache as mild to moderate on a 10-cm visual analogue scale. CONCLUSIONS: In view of the high incidence of headache and the need for treatment associated with the use of the 22-gauge Quincke needle, we recommend that this should not be used in the obstetric population. We are also aware that the incidence of post dural puncture headache could be further reduced by the use of small calibre pencil-point needles but these are currently very expensive and many obstetric units in developing countries may not be able to afford them.     

Patient-controlled epidural analgesia with fentanyl-bupivacaine: influence of prior dural puncture

BACKGROUND AND OBJECTIVES: Combined spinal epidural anesthesia (CSEA) involves the epidural administration of local anesthetic and opioid solutions adjacent to the prior dural puncture, potentially increasing their diffusion into the subarachnoid space. This study was designed to evaluate the influence of dural puncture on the adequacy and extent of analgesia, and drugs requirements of patient-controlled epidural analgesia (PCEA) in the postoperative period. METHODS: In this prospective double-blind study, 40 patients undergoing major abdominal surgery under general anesthesia followed with PCEA were randomly assigned to either group I (preoperative insertion of an epidural catheter) or group II (preoperative dural puncture with a 25-g Quincke needle + insertion of an epidural catheter). Postoperatively, a PCEA pump delivered an infusion of 0.1% bupivacaine + fentanyl (3 microg/mL) at 5 mL/h. Participants were allowed to self-administer 5-mL boluses of the same solution with a 15-minute lock-out interval. Hourly epidural solution requirements were recorded for 40 hours. Sensory and motor block, and pain scores were also analyzed. RESULTS: There was no difference between groups with regard to epidural solution requirements, pain scores, spread of sensory blockade, or intensity of motor block. CONCLUSION: Dural puncture with a 25-gauge Quincke needle, performed as part of CSEA, does not influence the drug requirements when a combination of 0.1% bupivacaine and fentanyl (3 microg/mL) is used for PCEA after major abdominal surgery.     

Grading of severity of postdural puncture headache after 27-gauge Quincke and Whitacre needles

Background: Small-gauge needles are reported to have a low incidence of complications. Pencil-point needles are associated with a lower frequency of postdural puncture headache (PDPH), but a higher failure rate than Quincke needles.
Methods: The incidence of PDPH was investigated in 200 patients under the age of 45, undergoing day-care surgery, after spinal anaesthesia with either 27-gauge Quincke or Whitacre needle. The severity of headache was graded as I (mild), II (moderate) or III (severe) using a grading system based on the visual analogue scale (VAS) associated with a functional rating (FG).
Results: The frequency of PDPH following the Whitacre needle was 0% and 5.6% after the Quincke needle ( P = 0.05). Two PDPHs were assessed as grade III, and three as grade II. All PDPHs occurred when the Quincke needle bevel was withdrawn perpendicular to the dural fibres following parallel insertion. No PDPH occurred when the bevel was inserted and removed parallel to the dural fibres ( P < 0.05). There was no statistical difference ( P >0.8) in the incidence of PDPH and postdural puncture-related headaches (PDPR-H) in patients with recurrent headaches or migraine compared to patients with no previous history of headaches.
Conclusions: We conclude that the 27-gauge Whitacre needle is the 'needle of choice' in patients with normal body stature. The incidence of PDPH following Quincke needles may not only be affected by the direction of the bevel during insertion but also during removal. Statistically, there was no gender variation in PDPH in this study (P=0.5). A previous history of recurrent headache or migraine does not predispose to PDPH.     

Comparison of 27-gauge (0.41-mm) Whitacre and Quincke spinal needles with respect to post-dural puncture headache and non-dural puncture headache

BACKGROUND: The incidence of headache after spinal anaesthesia has varied greatly between studies. We compared the incidence of postoperative headache in general and postdural puncture headache (PDPH) when using 27-gauge (G) (outer diameter 0.41 mm) Quincke and Whitacre spinal needles in ambulatory surgery performed under spinal anaesthesia. Methods: In a prospective, randomized study, 676 ASA physical status I-II day-case outpatients were given a spinal anaesthetic through either a 27-G (0.41 mm) Quincke or a 27-G (0.41 mm) Whitacre spinal needle. The incidence of any type of postoperative headache was assessed and the type of headache defined using a standardized questionnaire including PDPH criteria. The severity of the headache was defined using a 100-mm visual analogue scale. Results: For the final analysis, 529 patients were available (259 patients in the Quincke group and 270 patients in the Whitacre group). The overall incidence of postoperative headache was 20.0%, but the incidence of true PDPH was very low (1.51%). The incidence of PDPH in the Quincke group was 2.70%, while in the Whitacre group it was only 0.37% (P < 0.05). The overall incidence of non-dural puncture headache was 18.5% and did not differ between the study groups. Conclusions: True PDPH seldom occurs when a 27-G (0.41 mm) spinal needle is used, although postoperatively a non-specific headache is common. Using the 27-G (0.41 mm) Whitacre spinal needle further reduced the incidence of PDPH. Thus, we recommend routine use of the 27-G (0.41 mm) Whitacre spinal needle when performing spinal anaesthesia.     

A directional needle improves effectiveness and reduces complications of microcatheter continuous spinal anaesthesia

The present prospective randomized study compares the impact of two different spinal needle designs — non-directional versus directional — on the effectiveness of continuous spinal anaesthesia provided via a microcatheter in orthopaedic patients. Using the midline approach, a 28-gauge spinal catheter was inserted either through a 22-gauge Quincke needle (nondirectional, Group 1, n = 21) or a 22-gauge Sprotte needle (directional, Group 2, n = 21) under standardized conditions. The incidence of technical difficulties and postoperative complaints, onset time of analgesia at the level of T₁₀ and dose requirement of plain bupivacaine 0.5% were recorded. Postoperatively, the subarachnoid position of the catheters was radiographically evaluated. There was a higher incidence of technical problems during catheter insertion in Group 1 compared with Group 2 (71% vs 19%, P < 0.05). Onset time of analgesia was shorter (P < 0.05) and anaesthetic dose requirement was lower in patients in Group 2 than in Group 1. While 40% of the catheters were found in a caudal position in Group 1, all catheters were in a cranial position or at the level of the puncture site in Group 2 (P < 0.05). There was no difference in the incidence of postoperative complaints between the groups. The faster onset of analgesia and lower dose requirement of local anaesthetics associated with a lower incidence of technical problems suggest that there is greater effectiveness and safety when microcatheters are inserted using directional needles rather than non-directional needles.     

Hearing loss after spinal anesthesia is related to needle size

Audiograms were performed preoperatively and 2 days postoperatively in 28 patients given spinal anesthesia for transurethral resection of the prostate. In 14 patients 22-gauge and in 14 patients 26-gauge spinal needles were used. Hearing loss of 10 dB or more at any frequency was observed in 13 of 14 patients in the 22-gauge group and in 4 of 14 patients in the 26-gauge group. There was a statistically significant reduction in hearing level in the low-frequency range in patients in whom the 22-gauge needle was used. Hearing loss was unilateral at five frequencies and bilateral at one frequency. No cases of postspinal headache occurred. Audiometry may be a more sensitive indication of cerebrospinal fluid leak than postspinal headache.     

SPINAL ANAESTHESIA FOR CAESAREAN SECTION: COMPARISON OF 22-GAUGE AND 25-GAUGE WHITACRE NEEDLES WITH 26-GAUGE QUINCKE NEEDLES

We have studied 150 women undergoing elective Caesarean sectionunder spinal anaesthesia. They were allocated randomly to havea 22-gauge Whitacre, a 25-gauge Whitacre or a 26-gauge Quinckeneedle inserted into the lumbar sub-arachnoid space. The groupswere compared for ease of insertion, number of attempted needleinsertions before identification of cerebrospinal fluid, qualityof subsequent analgesia and incidence of postoperative complications.There were differences between groups, but they did not reachstatistical significance. Postdural puncture headache (PDPH)was experienced by one mother in the 22-gauge Whitacre group,none in the 25-gauge Whitacre group and five in the 26-gaugeQuincke group. Five of the six PDPH occurred after a singlesuccessful needle insertion. Seven of the 15 mothers in whommore than two needle insertions were made experienced backache,compared with 12 of the 129 receiving two or less (P < 0.001).We conclude that the use of 22- and 25-gauge Whitacre needlesin elective Caesarean section patients is associated with alow incidence of PDPH and that postoperative backache is morelikely when more than two attempts are made to insert a spinalneedle.     

Postoperative complaints after spinal and thiopentone-isoflurane anaesthesia in patients undergoing orthopaedic surgery Spinal versus general anaesthesia

Background. The present prospective study investigates the impact of a standardized technique of spinal and general anaesthesia on the incidence and consequences of postanaesthetic complaints dependent on age and sex of patients.
Methods. 433 orthopaedic patients underwent lower limb surgery in spinal (group 1) or general (group 2) anaesthesia. Spinal anaesthesia was performed with 0.5% hyperbaric bupivacaine using a 26-gauge Quincke needle. General anaesthesia was induced with i.v. injection of thiopentone, fentanyl and atracurium and maintained with 65% nitrous oxide and 1-1.5 Vol% isoflurane in oxygen. On postoperative day 4, patients were interviewed for onset and duration of postoperative complaints.
Results. The overall incidence of nausea/vomiting ( P =0.025) and sore throat ( P =0.001) was higher in group 2. In addition, nausea/vomiting was higher in patients between 20 and 60 years in group 2 compared with group 1. While the incidence of urinary dysfunction was higher in men after spinal ( P =0.04), nausea/vomiting was more frequent in women after general anaesthesia ( P =0.008). Analgetic requirements ( P =0.013), time of postoperative surveillance ( P =0.042) and frequency of treatment of postoperative complaints ( P =0.0001) was higher in group 2.
Conclusion. Spinal anaesthesia was associated with a lower incidence of postoperative complaints and treatments and a shorter surveillance compared to general anaesthesia. Specific complications related to spinal anaesthesia did not depend on age or sex and may allow for recommendation of this technique even in younger and female patients undergoing orthopaedic surgery.     

An in vitro study of dural lesions produced by 25-gauge Quincke and Whitacre needles evaluated by scanning electron microscopy

BACKGROUND AND OBJECTIVES: A study using scanning electron microscopy showed that although the laminas forming the dura mater are concentric and parallel to the surface of the medulla, the fiber layers' orientations are different in each sub-lamina, dispelling the conventional knowledge that all the fibers of the dura are arranged in a parallel direction. Thus, this study evaluated the dural lesions produced by Whitacre and Quincke spinal needles in the external and internal surface of the dura mater of the lower spine area in an attempt to gain more insight into the pathophysiology of postdural puncture headaches (PDPH). METHODS: The T11-L4 dural membranes from 5 fresh (immediately after extraction of organs for transplantation), male patients declared brain dead, ages 23, 46, 48, 55, and 60 years, were excised by anterior laminectomy. Morphologic orientation of the membrane and normal pH were maintained with an apparatus designed for this purpose. One hundred punctures (20 on each sample) at 90-degree angles were done with a new needle each time, 50 with 25-gauge Whitacre and 50 with 25-gauge Quincke needles. Half of the punctures with the Quincke needles were done with the bevel in parallel direction to the axis of the spinal cord, and the rest with the bevel perpendicular to it. Fixation in solutions of 2.5% glutaraldehyde phosphate buffer, followed by dehydration with acetone, was done 15 minutes after the punctures. After acetone was removed at ideal conditions of temperature and pressure, the specimens were then metallized with carbon followed by gold and inspected under a scanning electron microscope. RESULTS: Twenty-five of the Whitacre and 23 of the Quincke punctures were found for evaluation. There were no differences in the cross-sectional area of the punctures produced by the Whitacre or Quincke needles on the dura. The area of the dural lesions produced by 25-gauge Quincke needles, 15 minutes after they have been withdrawn, was 0.023 mm2 (confidence interval [CI] 95%, 0.015 to 0.027) in the external aspect (epidural surface) and 0.034 mm2 (CI 95%, 0.018 to 0.051) in the internal aspect (arachnoid surface) of the dural sac. The area of the lesions produced by the 25-gauge Whitacre needles was 0.026 mm2 (CI 95%, 0.019 to 0.032) and 0.030 mm2 (CI 95%, 0.025 to 0.036) in the external and internal surfaces of the dural sac, respectively. There were no significant differences in the cross-sectional areas of the punctures produced by the 25-gauge Whitacre or 25-gauge Quincke needles. Moreover, with Quincke needles the dural lesions closed in an 88.3% (CI 95%, 86.3 to 92.4) and 82.7% (CI 95%, 74.1 to 90.9) of their original sizes in the epidural and arachnoid surfaces, respectively. With Whitacre needles, the closure occurred in an 86.8% (CI 95%, 83.8 to 90.3) and 84.8% (CI 95% 81.7 to 87.3) in the dural and arachnoid surfaces, respectively. However, there were differences in the morphology of the lesions. The Whitacre needles produced coarse lesions with significant destruction in the dura's fibers while the Quincke needles produced a 'U'-shaped lesion (flap) that mimics the opened lid of a tin can, regardless of the tip's direction. Conclusions: The needles produced lesions in the dura with different morphology and characteristics. Lesions with the Quincke needles resulted in a clean-cut opening in the dural membrane while the Whitacre needle produced a more traumatic opening with tearing and severe disruption of the collagen fibers. Thus, we hypothesized that the lower incidence of PDPH seen with the Whitacre needles may be explained, in part, by the inflammatory reaction produced by the tearing of the collagen fibers after dural penetration. This inflammatory reaction may result in a significant edema which may act as a plug limiting the leakage of cerebrospinal fluid.     

Combined spinal and epidural anesthesia for orthopaedic surgery in the elderly]

The pros and cons as to which anesthesia is more beneficial, either spinal or epidural, prompted us to perform combined spinal and epidural block in the elderly undergoing lower limb surgery. The selected epidural space was entered with a 17-gauge Tuohy needle and a longer 26-gauge spinal needle was passed through it and into the subarachnoid space. Following the injection of required dose of 2% preservative-free lidocaine (isobaric), spinal needle was withdrawn and an epidural catheter was inserted. We could use this combined technique on 17 patients older than 80 yr (mean age; 84.5 +/- 3.9 years) with satisfactory results and without any serious cardiovascular change, as with 17 middle-aged patients (57.5 +/- 5.2 years). This combination of techniques provides a rapid onset and reliability of spinal block with high quality analgesia by supplementation through the epidural catheter during and after surgery. In the orthopaedic procedures on the lower limbs, combined spinal and epidural block is more useful even for the elderly over the age of 80 yr than spinal or epidural anesthesia alone.     

Einfluß der Punktionsnadel auf die subarachnoidale Katheterposition bei kontinuierlicher Spinalanästhesie

The subarachnoid position of the microcatheter has an impact on the outcome of continuous spinal anaesthesia (CSA). The present prospective, randomised study investigated the influence of two different spinal needles on the radiographically documented subarachnoid positions of microcatheters in CSA. In addition, the influence of the subarachnoid position of the microcatheter on onset time of analgesia, dose requirement of local anaesthetics, and level of analgesia was examined. Methods. Forty orthopaedic patients received CSA using a 28-gauge spinal catheter inserted either through a non-directional 22-gauge Quincke needle (group?1) or a directional 22-gauge Sprotte needle (group?2). After initial injection of 2?ml to a maximum of 5?ml of supplemental doses of 0.5% plain bupivacaine, onset time of analgesia at the level of T?10, dose requirement of bupivacaine, and the achieved analgesic level were registered. After surgery, a dye-enhanced AP X-ray film of the lumbar spine was performed for radiological control of the subarachnoid catheter position. Results. There was a higher number of cranial catheter positions in group?2 (60%) compared with group?1 (40%, P=0.037). In contrast to group?1, with 35% caudally directed catheters, no catheter was seen in a caudal position in group?2. Onset time of analgesia (P=0.0002) and anaesthetic dose requirement (P=0.037) were lower in patients with cranially directed catheters compared to patients with the catheters situated at the level of the puncture site or in a caudal position. Maximal analgesic levels were higher in cranially directed catheters compared with other localisations (P=0.022). Conclusions. Sprotte needles provide a higher number of cranially directed microcatheters, which are associated with faster onset of analgesia, lower dose requirement of local anaesthetics, and higher analgesic levels in CSA. The results suggest more effectiveness and probably more safety in microcatheter CSA using Sprotte needles for catheter insertion.