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INTRODUCCION: La cefalea post-punción de la duramadre (CPPD) es una complicación de la anestesia espinal, cuya incidencia se ve incrementada por otros factores como el tamaño de la aguja empleada, la disposición del bisel, el estado de embarazo y el número de punciones en la duramadre. MATERIALES Y METODOS: Se realizó una revisión sistemática, con los pacientes adultos sometidos a una anestesia espinal que han sido incluidos en experimentos clínicos en donde se compara la administración de bupivacaína hiperbárica con agujas traumáticas vs agujas atraumáticas de calibres 25, 27, o 29 Gauge entre enero 1 de 1993 a marzo 17 del 2013. RESULTADOS: Se seleccionaron doce estudios, la comparación más frecuente fue la de las agujas Quincke 27G con la agujas Whitacre 27G con un RR de 2,75 IC 95% (0,31 – 24,52), resultados similares en beneficio de las agujas Whitacre 27 hallo Shaikh JM. 2008 con un RR de 1,90 IC 95% (0,48 – 7,56), Santanen U.2004 encontró un RR de 7,30 IC 95% (0,90 – 58,90) y por ultimo Srivastava V. 2010 demostró diferencias en pacientes obstétricas entre las dos agujas con un RR 2,04 IC 95% (0,19 – 21,79). CONCLUSION: Las agujas atraumáticas vs traumáticas en el mismo calibre reducen la cefalea pos punción dural 2,69 veces cuando se usa el calibre 27. Al comparar igual diseño de punta en distintos calibres en agujas traumáticas, hay beneficio de los calibres de menor diámetro, siendo la aguja Quincke 27 la menos nociva y la aguja Quincke 25 una aguja con efectos deletéreos que no debería utilizarse en la práctica clínica. Magíster en Epidemiología Maestría INTRODUCTION: Post- dural puncture headache (PDPH) is an spinal anesthesia complication, its incidence is increased by other factors such as the size and kind of needle used, bezel arrangement, be pregnancy and the number of dural punctions. MATERIALS AND METHODS: A systematic review was conducted with adult patients undergoing spinal anesthesia that have been included in clinical trials where it is compared with hyperbaric bupivacaine traumatic vs. atraumatic needles gauge 25, 27, or 29 Gauge between January 1, 1993 to March 17, 2013 . RESULTS: Twelve trials were selected, the most frequent comparison of 27G Quincke needles with 27G Whitacre needles with a RR of 2.75 (95% CI 0.31- 24.52), similar results for the benefit of Whitacre needles 27 Shaikh hallo JM. 2008 with a RR of 1.90 (95% CI 0.48 - 7.56), Santanen U.2004 found an RR of 7.30 (95% CI 0.90 - 58.90) and finally Srivastava V. 2010 showed differences in obstetric patients between the two needles with a RR 2.04 (95% CI 0.19 - 21.79). CONCLUSION: Traumatic vs atraumatic needles in the same gauge reduce post dural puncture headache 2.69 times when using the 27 gauge. Comparing same tip design in different gauge with traumatic needles, smaller diameter sizes are better, Quincke needle 27 being the least harmful and the needle with more adverse effects is the Quincke 25 that should not be used in clinical practice.

A technique for real-time dynamic monitoring of force experienced by a spinal needle during lumbar puncture using a fiber Bragg grating (FBG) sensor is presented. The proposed FBG force device (FBGFD) evaluates the compressive force on the spinal needle during lumbar puncture, particularly avoiding the bending effect on the needle. The working principle of the FBGFD is based on transduction of force experienced by the spinal needle into strain variations monitored by the FBG sensor. FBGFD facilitates external mounting of a spinal needle for its smooth insertion during lumbar puncture without any intervention. The developed FBGFD assists study and analysis of the force required for the spinal needle to penetrate various tissue layers from skin to the epidural space; this force is indicative of the varied resistance offered by different tissue layers for the spinal needle traversal. Calibration of FBGFD is performed on a micro-universal testing machine for 0 to 20 N range with an obtained resolution of 0.021 N. The experimental trials using spinal needles mounted on FBGFD are carried out on a human cadaver specimen with punctures made in the lumbar region from different directions. Distinct forces are recorded when the needle encounters skin, muscle tissue, and a bone in its traversing path. Real-time spinal needle force monitoring using FBGFD may reduce potentially serious complications during the lumbar puncture, such as overpuncturing of tissue regions, by impeding the spinal needle insertion at epidural space. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

Reports have indicated that there are less postoperative complaints after the use of pencil pointed spinal needles. We compared a 24G Sprotte needle with a 27G Quincke needle in a randomised study of 200 healthy patients (49% females), aged 15-46 years. Four patients (2%) reported postdural puncture headache, three with the 24G Sprotte needle and one with the 27G Quincke needle. Thirteen patients (7%) suffered with nonspecific headache, with no significant difference between the two groups. Of the 57 (29%) who reported backpain, a significantly higher proportion had received spinal anaesthesia with the Sprotte needle (OR = 2.06). There was a significantly higher incidence of insufficient blocks after dural puncture with the Sprotte needle. Ease of needle insertion and number of puncture attempts was the same for both needle types.

Objective To assess fetlock joint contamination with tissue debris and hair after arthrocentesis. Study Design Experimental. Animals Fetlock joint tissues (n = 10 horses). Methods Soft tissue flaps including the joint capsule were dissected from the dorsal fetlock joints of 7 anesthetized horses leaving an intact proximal base. Needles inserted through the tissue flaps were flushed into tissue cell culture plates and examined for debris. Studies were repeated on excised fetlock tissue preparations after being stored for 5 days. Variables included gauge and type of needle, insertion of spinal needles with and without a stylet, angle of insertion, length of hair, and ante- and postmortem needle insertion. Tissue fragments collected from 3 horses were cultured for bacteria. Results Compared to 20 g disposable needles inserted perpendicularly through unclipped skin, the odds ratios (ORs) for hair contamination were significantly greater for 20 g spinal needles without a stylet, and significantly less for 22 g spinal needles inserted with a stylet and for angled insertion of disposable needles. Tissue contamination OR was significantly less for 20 g spinal needles inserted without a stylet, angled insertion, and clipped hair. Bacteria were isolated from 2.6% of tissue fragments. Conclusions Angled needle insertion reduces joint contamination with tissue and hair. Spinal needles should be inserted with a stylet in place and 22 g spinal needles are preferable to 20 g spinal needles. Joints may be contaminated with bacteria after routine surgical preparation of skin.

BackgrounAttempts have been made to reduce the incidence of postdural puncture headache (PDPH) after spinal anesthesia by changing the size and design of the needle. We wished to determine whether these strategies are effective in reducing PDPH and whether they affect the incidence of back pain and

Spinal needles with a pencil-point tip and those of a finer gauge are known to be associated with a lower incidence of postdural puncture headache. This study set out to determine if fine pencil-point needles were acceptably easy to use in routine clinical practice. Two hundred and twelve women undergoing elective Caesarean section were randomly allocated to receive a subarachnoid block using either a 25 G or 27 G Whitacre needle. Factors determining ease of needle use, adequacy of block, incidence of postdural puncture headache, backache and neurological sequelae were assessed. Successful intrathecal injection was achieved in all patients in the 25 G group. Using the 27 G needle, the anaesthetist failed to reach the subarachnoid space in eight patients of which seven subsequently had a successful intrathecal injection with a larger needle. These failures were attributed to excessive needle flexibility which was the only significant difference in ease of use between the 25 G and 27 G needles. In the 25 G group, there was one severe postdural puncture headache which required an epidural blood patch and three mild headaches which resolved spontaneously. There were no postdural puncture headaches in the 27 G group. We conclude that the final choice of needle is a compromise between the ease of use and lower failure rate of the 25 G needle and the, as yet unproven, possibility of a lower incidence of postdural puncture headache with the 27 G needle.

WOS: 000179516900016 PubMed: 12604283 Postdural puncture headache is one of the most serious complications of spinal anesthesia. In this study, spinal needles of various types and shapes were used to investigate the amount of fluid leakage in dural puncture under various pressures. Dura samples received from 10 cadavers were fixed in an in vitro model. The dural punctures were inflicted with 22 G, 25 G, and 27 G Quincke; 25 G Withacre; 25 G, 27 G Pencan, and 26 G Atraucan spinal needles. The fluid, which leaked during the process, was collected under the pressures of 0, 25, 50, 100, and 150cm H2O in a one-hour period for each level. The holes in the dura were studied under the light microscope. While 22 G and 25 G Quincke needles were used, the fluid leakage directly correlated with the amount of liquid, the diameter of the needle, and the pressure used. The puncture of 25 G Withacre and 25 G Pencan presented a leakage which did not significantly vary with the liquid pressure and was of lesser amount. In 26 G Atraucan, 27 G. Pencan, and 27 G Quincke inflicted punctures, little liquidwas collected and it did not vary with differing pressures. Thus, no significant correlation was established between the needle diameter and the puncture. It was concluded that the sharp-ended needles could not endure changes in the pressure. However, those needles with a very thin diameter and a pencil tip were considered as safe tools for anesthetic practice. (C) 2002 Elsevier Science Ltd. All rights reserved.

Parallel-walled spinal needles ≤ 22 G are routinely used for lumbar puncture, despite a reported ≥ 32% incidence of post-dural puncture headache. A tapered spinal needle (22 G shaft, 27 G tip) is in use in our institution. We hypothesized that despite the smaller dural puncture hole, this needle has similar cerebrospinal fluid (CSF) pressure equilibration times and CSF sampling times to a standard 22 G needle and assessed a range of spinal needles using an experimental pulsatile CSF reservoir.The pulsatile CSF reservoir had an oscillating pressure varying between 25 and 15 cm H(2)O at a cycle frequency of 80 s(-1). We tested seven parallel-walled spinal needles (18-27 G) and the tapered 22/27 G needle. CSF pressure was measured every 2 s by manometry. The time to collect 1 ml CSF samples was measured. Saline 0.9% and mannitol 20% were tested separately. One-way ANOVA with Bonferroni post-hoc test was used to compare 22G, 27G and 22/27G needles.The mean [standard deviation (sd)] CSF pressure equilibration time (saline) was 40.7 (6.4), 108.7 (6.1), and 51.3 (4.6) s for the 22, 27, and 22/27 G needles (P0.0001 for comparisons between 27 G and other needles). The mean (sd) CSF sampling time (saline) was 40.3 (3.1), 225.3 (10.0), and 63.0 (5.2) s for the 22, 27, and 22/27 G needles (P0.0001 for comparisons between 27 G and other needles, and P= 0.019 between 22 and 22/27 G needles). Saline was different from mannitol for both measurements and all needles (P0.0001).A 22/27 G tapered spinal needle has similar flow properties to the 22 G needle, despite a 27 G tip.

Summary Although the idea of combining the advantages of epidural and spinal anaesthesia is not new, widespread application has only been possible since the recent introduction of high quality long spinal needles of extremely small diameter. However, for the original double interspace technique described by Brownridge (1979) no special material is needed and the epidural catheter can be introduced before the spinal anaesthetic is injected. For the modern single segment method, special double lumen epidural needles are available that also allow the insertion of the epidural catheter before the actual injection of the spinal anaesthetic. The opposite happens during the needle through the Tuohy needle technique. A small long spinal needle is introduced through an ordinary epidural needle, and the spinal injection precedes the insertion of the epidural catheter. There still is some controversy on the optimum length, diameter and shape of the bevel of the spinal needle. Adaptations have been made to the epidural needle for its use in CSE anaesthesia. The literature documents the use of CSE anaesthesia in an impressive variety of surgical interventions, but caesarean section seems to have become a favourite indication. A meticulous technique, using carefully selected materials, achieves a degree of flexibility and effectiveness unobtainable with either method alone.

We present a case of intravascular injection in a 41-year-old female during cervical selective nerve root injection using a 22-gauge 3.5-inch Whitacre-type pencil-point subarachnoid needle with a curve placed at the distal tip positioned using continual live fluoroscopic guidance. After negative aspiration for blood and cerebrospinal fluid and no elicited paresthesias during the procedure, 1 mL of contrast was injected. Initial imaging at C6 captured the outline of the nerve root along with a significant amount of transient vascular runoff. This case report demonstrates that Whitacre-type spinal needles do not prevent vascular injection, and that aspiration of the needle is not a reliable sign of intravascular injection.

The curare revolution in anesthesia, initiated at the suggestion of Lewis H. Wright,! had several parallels with its pre­ decessor, the local anesthesia revolution begun by Carl Koller with cocaine. Both were produced with an alkaloid, both ap­ plied pharmacologic information that had long been available, and in both a vast therapeutic advantage involved terrifying new dangers. The centenary of Koller's con­ tribution offers an opportunity to sketch its dramatic, not to say melodramatic, con­ text, accented with notes from the lullaby of the coca leaves and the early stabs with spinal needles. Koller's epochal finding, in Vienna in 1884, was that the ocular instillation of cocaine completely abolished sensibility of the cornea and conjunctiva. This was an­ nounced and demonstrated at the Congress of Ophthalmology in Heidelberg, Germany, by Dr. Josef Brettauer. Brettauer did so on Koller's behalf because Koller himself, at the age of 27, was an impecunious intern and could not afford the cost of the rail journey from Vienna. It was ill fortune enough that Koller had to pass up his mo­ ment of his triumph, but there was worse to come. Vienna in 1884 was gloomy, especially at night. There was no electric light. There was none anywhere in Europe. The first public power station had been built in New York in 1882, but a transatlantic follow-up was still 1 year away. Vienna was the capi­ tal of a turbulent multinational empire and a Mecca of medical education. Modern medicine was young, and drug action was poorly understood but surgery was already entering a new era in which Lister's sys­ tem of antisepsis had made it safe to open the abdomen. Although asepsis and surgi­ cal gloves still lay in the future, Billroth had performed the world's first gastrectomy in Vienna in 188l . The Austrian Novara expedition1 had brought back to German-speaking Europe a big batch of the leaves of ErythroxylulIl coca, the sacred plant of the Incas; an active principle had been isolated from the leaf, but its properties

The study, the first part of which was published in 2008, looked at, prospectively, how effective and safe new, non-traditional connectors were for use in spinal connector equipment such as spinal needles and infusion lines. The researchers analysed existing evidence on adverse incidents in this area, held workshops to discuss the problem, tested new devices with a simulator, and evaluated them in clinical practice trials at four different hospitals in England.

Four fine-needle aspiration biopsy needles with different tip configurations were used in 133 patients with abdominal lesions. The 20-gauge needles were used in random sequence by several physicians. The specimen from each of the 522 needle passes was evaluated by two cytopathologists for adequacy to render a diagnosis and for the presence of cell block material. The Franseen needle produced a 16% and 9% better yield for diagnostic material than did the cut biopsy and spinal needles (P less than .05), respectively. The Westcott needle was better than the cut biopsy needle by 13%, and the spinal needle produced an 11% better yield than did the cut biopsy needle. Differences did not exist in liver biopsies but were present in pancreatic biopsies. The spinal needle was the least successful in yielding cell block material. Use of the cut biopsy needle resulted in the largest proportion of inadequate specimens, except its yield in cell blocks in the liver was 25% higher than that of the Westcott needle. The authors conclude that not all unusual designs for 20-gauge needle tips render results superior to those of the simple spinal needle.

In the past, local field block anesthesia for retromammary breast augmentation has usually been performed with spinal needles. In this article, I present an alternative, a cannula-like needle that delivers large amounts of very dilute local anesthetic in an extremely quick fashion for retromammary breast augmentation. Besides being a time-saver, this needle also offers the patient better anesthesia and improved safety. Another advantage is that the retromammary pocket is partially hydrodissected by the large amount of dilute anesthesia delivered, thereby further decreasing intraoperative time. A description of the instrument, its usage, and its pros and cons are given.

Summary Background: In adults, pencil point spinal needles are known to be less traumatic and hence to be superior compared with cutting point needles in respect of postpuncture complications. In children, only a few trials have evaluated the difference in the incidence of postdural puncture headache (PDPH) using spinal needles with different tip designs. The aim of this study was to evaluate the success rate and the incidence of PDPH and backache following spinal anesthesia (SA) with the two types of needles currently in use for children. Methods: This is a retrospective study of prospectively collected data. The success rate and postpuncture complications of 26G cutting point (Atraucan®) spinal needle were compared with 27G pencil point (Pencan®) spinal needle in 414 children aged 2–17 years undergoing surgery with SA. Results: Both needles had similar first-attempt success rates: 87% in the cutting point group and 91% in the pencil point group (P = 0.16). Pencil point needles caused less PDPH compared to cutting point needles; 0.4% vs 4.5%, respectively (P = 0.005). Both needles caused similar backache (P = 0.08). No severe neurologic symptom was reported for both needles. Conclusion: The data suggest that 27G pencil point spinal needles lead to less PDPH compared to 26G cutting point spinal needles in children.

BACKGROUND AND OBJECTIVE Recurrent, bilateral or unilateral, persistent or transient, mild or profound hearing loss has been reported after spinal anaesthesia. We studied the effects of the needle type (Quincke, ballpen, pencil-point spinal needles) on hearing loss after spinal anaesthesia with the use of pure-tone audiometry. METHODS Forty-five ASA physical status I patients scheduled for elective inguinal herniorraphy with spinal anaesthesia were enrolled in the study. The patients were randomly divided into three groups. Group Q (n = 15) patients received spinal anaesthesia through a 25-gauge (G) Quincke spinal needle, group B (n = 15) patients received the same through a 25-G ballpen spinal needle and those in group P (n = 15) received the same through a 25-G pencil-point spinal needle. Patients were interviewed about postoperative complaints such as postdural puncture headache, vertigo, nausea-vomiting, transient neurological symptoms and major neurological deficits. Pure-tone audiometry was performed by an audiologist at specific time intervals. RESULTS The number of patients who had greater than 10 dB hearing loss in group Q was significantly more than that found in group B and group P at 250, 500, 4000 and 6000 Hz on postoperative day 1. When group B and group P were compared for change in hearing, no statistically significant difference was detected at any frequency tested. CONCLUSION Because the use of ballpen and pencil-point needles reduces hearing loss after spinal anaesthesia, these needles are preferred.

Regional anaesthesia for Caesarean section is increasing in popularity — a trend encouraged by obstetric anaesthetists because of its greater safety and the emotional benefits tomother and baby. Such anaesthesia is easier to provide for elective cases, but even in the case of many emergency or semi-emergency Caesarean sections there may be time to extend an epidural already in use, or to use spinal anaesthesia. The reason for the difficulty in providing effective epidural anaesthesia in some cases has been clarified with the identification of variable bands and septa in the epidural space. Spinal block gives more reliable anaesthesia but carries a higher risk of hypotension so that monitoring to detect, and measures to prevent it must be particularly rigorous. Two new developments which are likely to play a part in improving regional anaesthesia for Caesarean section and post-operative pain relief are continuous spinal and combined spinal-epidural techniques. In the case of the former, particular interest is being focused on very fine microcatheters, but the incidence of post-spinal headache with larger catheters is also being reassessed. The combined technique gives the speed of onset and reliability of the spinal block with the flexibility of analgesia provided by the epidural catheter, as well as the advantage of the Tuohy needle acting as guide for the very fine spinal needles.

The compatibility between spinal needles and their introducers varies between manufacturers and can significantly influence the usable length of the spinal needle available resulting in failure to locate CSF in larger patients. The usable length of 90-mm pencil point spinal needles from four manufacturers ranged from 68 to 79 mm when the needle was used in combination with its introducer. A new purpose-built introducer needle is described which, when used with a 25 g or finer spinal needle, maximises the usable length of the needle. Using this new introducer the usable needle length of a 90-mm Whitacre needle was increased by a further 7 to 86 mm resulting in only a 4 mm loss of total needle length. The new introducer was well received by users.

Ultrasound fine needle aspiration cytology (US-FNAC) represents the most effective test available to distinguish between benign and malignant thyroid nodules, with an accuracy approaching 95%. The major limit of this procedure it is the rate of inadequate specimens which is reported to be from 10% to 31%. Also because cost considerations have always been important and have recently become even more relevant for clinical guidelines in many countries, it is desirable to limit the number of inadequate samples. Recently, we have shown that the use of stylet needles greatly reduces inadequate cytological specimens in thyroid nodules with an intranodular vascular pattern. With the aim to improve our previous results, we have extended our procedure to all thyroid solid nodules. Between February 2004 and March 2006, 312 consecutive patients with thyroid nodule without intranodular vascular pattern at color-Doppler evaluation were enrolled in this prospective study. US-FNAC was performed by two different 25 gauge needles (Neolus [Ns] and Yale Spinal [YS]), and the two procedures were performed in alternate sequence on consecutive patients. Adequate specimens were observed in 145 (92.9%) and 153 (98%) nodules respectively investigated by Ns and in YS (p0.005). The total cost to obtain a cytological diagnosis by Ns was of euro 12210.2 (156+12 repeated US-FNAC), whereas it was of euro 12449.7 by YS (156+3 repeated US-FNAC). Our data suggest that spinal needles are associated with a low proportion of inadequate FNAC, without increase of total direct cost, considering also the number of FNAC repetitions needed; therefore, their routine use could be taken into account.

Since the discovery of spinal anesthesia in 1885 by J Leonard Corning, spinal needles have been modified to simplify their use and minimize complications. Needle design variables, such as diameter, tip design and orifice location, have been altered to enable rapid flow of cerebral spinal fluid (CSF) and injected medications, yet simultaneously limit dural trauma and loss of CSF. CSF loss can result in a severe postdural puncture headache (PDPH). Blunt pencil-point tip needles have been observed to cause a lower incidence of PDPH than similar sized sharp, cutting tip needles. Smaller diameter needles are also associated with a lower incidence of PDPH. A recent alteration in spinal needles is not to the needle per se, but rather the microcatheters placed through them; currently used in Europe, such catheters are again being evaluated in the USA. Further advancements in spinal needles will most likely involve some of the design elements previously altered, as well as new features not yet recognized as important at this time.

Adequate patient positioning with a traction device to provide sufficient distraction of the hip to access the femoral-acetabular joint is the first and most important step in hip arthroscopy. Cannulated instruments provide reproducible access to the hip joint from every portal by following guidewires into the joint. These guidewires are positioned through long spinal needles via fluoroscopic navigation and, subsequently, direct arthroscopic vision. By using these techniques adequately, the risk of iatrogenic damage to the hip joint is reduced. The traditional option for introduction of instruments to the hip joint has been the use of closed working cannulas of increasing diameters to accommodate instruments of different sizes. Curved instruments usually require large-diameter standard cannulas or flexible plastic cannulas. Large cannulas increase the risk of damage to the articular cartilage and may not accommodate every curved instrument. Flexible cannulas may leave debris inside the joint if damaged. Slotted cannulas allow curved instruments to be introduced into the hip joint by sliding them through their open side. With the instrument inside the joint, the slotted cannula can be slid out for better instrument mobility. It can also be reinserted around the previous instrument for instrument or portal exchange.

Management of an open wound is a problem frequently encountered in the treatment of fractures. Skin grafting, rotational flaps, free flaps, and healing by secondary intention add a considerable amount of morbidity and cost to the patient. Therefore, it is ideal to obtain primary closure when possible. This communication describes a technique that uses spinal needles, using towel clips and the natural stretching ability of the skin to enable primary closure of wounds. The technique described uses dermatotraction to stretch the skin is a cost-effective way to achieve primary closure of large wounds with supplies that are readily available in every operating room.

Why do doctors not do what is known to work? There would seem to be only a few possible reasons: they may be unaware of the evidence; they may disagree with the evidence; or they may accept the evidence but choose to disregard it. On p. 158 Dr Sado and Dr Deakin1 report on doctors' use of local anaesthesia for venous cannulation and find that little has changed in a decade:2 very few ward doctors routinely use local anaesthesia for cannulation, despite an abundance of evidence that it makes the procedure much more bearable (the same is true of arterial puncture, but here I focus on venous cannulation because it is so much more common). The unanimous conclusion of those who have investigated the matter is that patients and volunteers find the pain of local anaesthetic infiltration less than that of cannulation,3–12 even with cannulae as small as 20 gauge, and cannulation is not made more difficult by the procedure.6,9 Could it be that doctors accept the efficacy of local anaesthetic but do not use it because the pain of cannulation is not thought bad enough to warrant the extra hassle? My own impression from observing and talking to other doctors, supported by the findings of Sado and Deakin and others,1,11 is that this accounts for part of their reluctance—the pain of cannulation is considered regrettable but a fact of life (no pain, no gain). But another factor, as many have found, is simple ignorance: they are unaware of the evidence and nobody has ever taught them to use local anaesthesia for these procedures.2,13,14 The observation that anaesthetists are more likely to use local anaesthetic than doctors in other specialties1,2,13,14 may reflect their central preoccupation, in clinical work, with the prevention and control of pain. They also know how much more difficult it can be to anaesthetize an anxious patient stressed by the siting of a cannula than a calm one. Another possibility is that anaesthetists are simply more familiar with local anaesthetics and therefore more comfortable using them. Or perhaps anaesthetists are less likely than others to regard the pain of cannulation as 'normal' because so many of their patients—those having elective surgery for example—are not uncomfortable to start with and are less tolerant of new pain. A parallel can be drawn with the use of spinal needles: for years it has been known that the incidence and severity of postdural puncture headache can be lessened by use of small conically tipped needles, but physicians and surgeons have been been much slower to apply this knowledge than their anaesthetic colleagues.15 Does it matter? To answer this question you merely have to ask anyone who has ever had an intravenous cannula inserted—or better still, ask a colleague to insert one in your own arm (without local, of course). Not everyone suffers severe pain, but many people do. The grateful relief of patients who, after experiencing their first pain-free cannulation, have admitted that the pain of previous cannulations has led them to fear this procedure above most others, will be familiar to anyone who routinely uses local anaesthetic. And the squirming, distressed patient who suffers cannulation with clenched teeth and tears in the eyes will be familiar to anyone who routinely does not. So yes, the pain of cannulation does matter, and since we have the ability to prevent it at low cost and with negligible risk, how can we justify not doing so? Although other manoeuvres can reduce the pain of cannulation, such as 'darting' the cannula through the skin or getting the patient to cough,16 and although other analgesics or drug delivery systems have also been shown to be effective,17,18 local anaesthetic injection is the only readily available method that allows slow, careful and painless cannulation, improving the chance of success and maintaining the patient's confidence. Box 1 Method for painless injection of local anaesthetic before venous cannulation Allow alcohol cleanser to dry completely Draw 1 mL lidocaine 1% into a 2 mL syringe and attach a 25 gauge (orange) needle Position the needle above the injection site so that its bevel is parallel to the skin Firmly press the bevel flat against the skin with the thumb of the non-dominant hand, while applying firm constant pressure to the plunger of the syringe with the dominant hand. A small amount of local anaesthetic may leak out but ignore this Very slowly, advance the needle (still with the bevel parallel to the skin and still with pressure applied to the plunger) until a small white bleb begins to appear in the skin. At this point, stop advancing but continue to inject slowly until the bleb grows to about 4–5 mm Further lidocaine can be slowly injected under the skin if the vein is deep; otherwise the intradermal bleb will be adequate for cannulation of a superficial vein The cannula may now be advanced painlessly through the skin. Finally, for anyone still sceptical, there is a little-known way of injecting the local anaesthetic that is virtually pain-free, as the many trainees on whom I have demonstrated it over the years can personally testify. It does not rely on mixing additives with the local anaesthetic19 or having to use special needles.12 This technique (Box 1) has transformed the way I have cannulated over the past decade, and I only wish that I could remember who first described it to me, so that I could thank him or her on behalf of my patients.

This study investigated whether the tips of spinal needles are damaged during the process of spinal anaesthesia by impact on bone, by repeated attempts at performing the block or by the use of an introducer. Used spinal needles from five different hospitals were carefully resheathed after use and a questionnaire completed. The needles were examined under a light microscope with the observer unaware of the questionnaire data. Two hundred and twenty-two needles were examined, of which 36 were damaged. Five unused control needles of each type were also examined and all were found to be undamaged. There was no significant difference between the damaged and undamaged used needles with respect to impacts on bone or the number of attempts. Pajunk 24G Sprotte needles were significantly less likely to sustain damage when the integral introducer was used as compared to an alternative introducer.

UNLABELLED In this study, we examined the characteristics of a newly designed spinal needle (Ballpen [B]) with a pencil-like tip formed by a stylet that is withdrawn after penetration of the dura. The main goal was to examine whether the use of the B needle could reduce performance time by improved puncture conditions in comparison with the Sprotte (S) needle. Seven-hundred patients at 4 hospitals received single-dose spinal anesthesia with a 25-gauge B or S needle and 0.5% bupivacaine. The performance time of spinal anesthesia was defined as the time between insertion of the introducer needle and the first identification of cerebrospinal fluid in the hub of the spinal needle. Failed spinals were assessed when patients required general anesthesia. On postoperative Day 2-4, all patients were visited and interviewed. Groups did not differ with respect to demographics, puncture site, and dose of bupivacaine. Performance time was 98 +/- 145 s in Group B and 103 +/- 159 s in Group S (P = 0.68). The failure rate in Groups B and S was 3.8% and 3.9%, respectively, and the incidence of postdural puncture headache was 1.8% and 0.9% (P = 0.50), respectively. We conclude that there was no difference in technical variables or outcome between the B and S needles. IMPLICATIONS This multicenter study examined characteristics of the newly designed Ballpen needle with the Sprotte needle in 700 patients undergoing lower abdominal or extremity surgery in single-dose spinal anesthesia. Technical variables and side effects were comparable between both noncutting spinal needles.

The important features which determine the ease of use of spinal needles include rapid detection of cerebrospinal fluid, minimal delay before injection and low resistance to injection of local anaesthetic. We investigated these three parameters among the following 11 spinal needles: Becton-Dickinson 22 G, 25 G and 27 G Whitacre, 25 G and 27 G Quincke; B. Braun Spinocan 22 G, 25 G and 26 G Quincke; Vygon 25 G Whitacre, Portex 26 G Pencil Point and the 24 G Sprotte. Three needles of each type were tested using an artificial cerebrospinal fluid model maintained at body temperature and at two hydrostatic pressures of 12 and 50 cm of water. The Becton Dickinson 27 G Whitacre has an immediate detection time at both pressure heights, a reasonably short 'ready to inject' time and relatively low resistance to injection, which, together with a reported low rate of postdural puncture headache, would indicate that it is the most appropriate for spinal anaesthesia. The 25 G Whitacre types would be the next most suitable to use.

Spinal anaesthesia developed in the late 1800s with the work of Wynter, Quincke and Corning. However, it was the German surgeon, Karl August Bier in 1898, who probably gave the first spinal anaesthetic. Bier also gained first-hand experience of the disabling headache related to dural puncture. He correctly surmised that the headache was related to excessive loss of cerebrospinal fluid (CSF). In the last 50 yr, the development of fine-gauge spinal needles and needle tip modification, has enabled a significant reduction in the incidence of post-dural puncture headache. Though it is clear that reducing the size of the dural perforation reduces the loss of CSF, there are many areas regarding the pathogenesis, treatment and prevention of post-dural puncture headache that remain contentious. How does the microscopic pattern of collagen alignment in the spinal dura affect the dimensions of the dural perforation? How do needle design, size and orientation influence leakage of CSF through the dural perforation? Can pharmacological methods reduce the symptoms of post-dural puncture headache? By which mechanism does the epidural blood patch cure headache? Is there a role for the prophylactic epidural blood patch? Do epidural saline, dextran, opioids and tissue glues reduce the rate of CSF loss? This review considers these contentious aspects of post-dural puncture headache.

Study Objective: To determine whether the window design of pencil-point spinal needles leads to deformation under lateral or axial loading conditions. Design: Independent-measure, multigroup study of the force required to deform needles. Setting: Independent testing laboratory. Measurements and Main Results: The force necessary to bend 22- and 24-gauge Sprotte, 22- and 25-gauge Whitacre, and 22- and 25-gauge Quincke needles was measured using an Instron gauge (Instron Corp., Canton, MA) after microscopic verification of needle uniformity. Effects of lateral and axial forces were evaluated in separate experiments. The force needed to bend the Sprotte needles was less than that needed for the Whitacre and Quincke needles of similar size when lateral or axial pressure was applied. Microscopic inspection of the needles showed a marked variability in the window area placement in a single lot of Sprotte needles. Examination of the needle tips demonstrated that the Sprotte needles were most likely to bend at the needle window, while the Quincke and Whitacre needles deformed at the point of clamping. Conclusions: The Sprotte needles have an inherent design weakness to lateral and axial pressure, which may result in a greater number of needle tip deformations upon needle insertion. The nature of this deformation may result in difficulty in needle withdrawal and possibly fracture of the needle tip.

The effect of different size (25-, 27- and 29-gauge) Quincke-type spinal needles on the incidence of insertion difficulties and failure rates was investigated in a randomised, prospective study with 300 patients. The needle size was randomised but the insertion procedure was standardised. The time to achieve dural puncture was significantly longer with the 29-gauge spinal needle compared with the larger bore needles and was due to the greater flexibility of the thin needle. However, the difference was less than 1 min and cannot be considered clinically significant. There were no significant differences between groups in the number of insertion attempts or failures and the same sensory level of analgesia was reached with all the needle sizes studied. Postoperatively, no postdural puncture headaches occurred in the 29-gauge spinal needle group, whilst in the 25- and 27-gauge needle groups, the postdural puncture headache rates were 7.4% and 2.1% respectively. The incidence of backache was similar in all study groups. We conclude that dural puncture with a 29-gauge spinal needle is clinically as easy as with larger bore needles and its use is indicated in patients who have a high risk of postdural puncture headache.

Background Prior experience with the combined spinal-epidural technique (CSE) for labor analgesia demonstrated a high (up to 14%) failure rate because of failure to obtain cerebrospinal fluid (CSF) or lack of response to appropriate doses of intrathecal sufentanil. The current study was designed to test whether a longer needle with a shorter side port (Gertie Marx needle; 127 mm long) would eliminate failures to obtain CSF compared with the needle we had used previously (Sprotte needle; 120 mm long). Methods Seventy-three parturients were randomly assigned to have a CSE performed with one of these two needles. After identifying the epidural space with an 18-gauge Touhy needle at the L2-L3 or L3-L4 interspace, the spinal needle was introduced through the Touhy needle until penetration of the dura was felt or until the needle was maximally inserted. If no CSF was obtained, the alternate needle was tried. After obtaining CSF, 10 microg sufentanil diluted in 1.8 ml saline was injected. Verbal pain scores (0-10) were obtained every 5 min for 30 min. Results Failure to obtain CSF occurred six times in the Sprotte group compared with none in the Gertie Marx group (P < 0.05). In all six failures in the Sprotte group, the Gertie Marx needle subsequently proved successful in obtaining CSF. There were no differences in pain scores between the groups. Conclusions The extra length of the 127-mm Gertie Marx needle resulted in a higher success rate for obtaining CSF when used in the CSE technique. Side port design was not a factor influencing success in this clinical setting.

The most commonly used technique in routine spinal anaesthesia practice is the midline approach, compared to the lateral or paramedian approach. With the better understanding of the technique and introduction of fine gauge spinal needles, this practice needs a rethinking. Lateral approach was used in 60 patients undergoing different surgical procedures below the umbilicus, using 24 or 25 gauge, Quincke spinal needle without an introducer. The result was gratifying. In 77% of the cases the subarachnoid space could be entered in the first attempt. There was no failure. No patient complained of postdural puncture headache or post operative backache. Only one patient reported paraesthesia during needle placement without any residual effect. Various other advantages of the technique are discussed. Thus with due practice, lateral approach is found to be superior in modern day spinal anaesthesia.

IMPLICATIONS Features suggestive of subdural block appeared after an apparently normal subarachnoid block. The long bevel of the reusable Quincke-type spinal needle may have contributed to the development of this complication. We propose that spinal needles should have a smaller bevel to minimize the possibility of such a complication.

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.

Eberhard Albert Lux, Astrid Althaus Fakultät für Gesundheit der Universität, Witten-Herdecke, Germany Abstract: In this retrospective study, the question was raised and answered whether the rate of postdural puncture headache (PDPH) after continuous spinal anesthesia with a 28G microcatheter varies using a Quincke or a Sprotte needle. The medical records of all patients with allogenic joint replacement of the knee or hip or arthroscopic surgery of the knee joint undergoing continuous spinal anesthesia with a 22G Quincke (n=1,212) or 22G Sprotte needle (n=377) and a 28G microcatheter during the past 6 years were reviewed. We obtained the approval of the ethical committee. The rates of PDPH were statistically not different between both groups: 1.5% of patients developed PDPH after dura puncture with a Quincke needle and 2.1% with a Sprotte needle in women and men. Keywords: continuous spinal anesthesia, postdural puncture headache (PDPH), Sprotte needle, Quincke needle

A simple technique of powered subcutaneous instillation of split-thickness skin graft donor sites in burn patients and other plastic surgical patients has been developed. The necessary equipment required, including a standard pneumatic tourniquet, arterial pressure bags and spinal needles, is available in any plastic surgery operating theatre. In over 300 cases in which it has been employed, no complications have been encountered.

Dear editors, In his recent paper published in this journal, Matas addresses one important and well-studied aspect of postdural puncture headache prevention, i.e., the use of atraumatic spinal needles. On the other hand, when focusing on standard post-lumbar puncture recommendations, particularly 24 hours bed rest and controlled fluid ingestion, the author refers to four papers in which not only these recommendations are not enforced but, indeed, are explicitly disregarded – as in the case of bed rest – or, at least, considered as unproved, as in the case of fluid ingestion. Although a remark is made about the lack of “experimental support” to the above recommendations, the author does not mention the existence of positive evidence showing the lack of effect of post-lumbar puncture bed rest on the incidence of post-puncture headache, gathered during the last years and analyzed in recent systematic and non systematic reviews. Considering that the inefficacy of these measures had by now been consistently demonstrated by consecutive prospective trials, as already acknowledged by the headache community, we think that scientific evidence must prevail and the standard bed rest and fluid intake advices following lumbar puncture should be abandoned, instead of reinforced.

Purpose: To describe obstetric anesthesia in Canada as practiced in 1997: to identify practices at variance with the literature and the opinions of experts: and to identify questions for future research. Methods: In 1997, a detailed postal questionnaire asking about the practice of obstetric anesthesia was mailed to all 1,539 specialist anesthesiologist members of the Canadian Anaesthetists’ Society residing in Canada. Nonresponders were mailed a second questionnaire three months later. Results: There were 865 completed questionnaires returned for analysis (56.2%). Of these, 522 anesthesiologists practiced obstetric anesthesia (60.3%). The data were subdivided into those from anesthesiologists with a full or part-time university based practice (40.1%) and those from a community based practice (59.9%). University based and community-based anesthesiologists have very similar patterns of practice. Specific areas where anesthesia practice was different from current recommendations included: (1) information provided when obtaining consent for labour epidural analgesia, (2) use of opioids and local anesthetics for initiation of epidural analgesia, (3) use of coagulation testing in preeclampsia, (4) the common use of cutting spinal needles, (5) use of neuraxial morphine and nonsteroidal anti-inflammatory agents after Cesarean deliveries, (6) optimal treatment of neuraxial opioid side effects, (7) when to insert an endotracheal tube for general anesthesia after delivery, and (8) withdrawing epidural catheters through epidural needles. Conclusions: This survey presents reference data on the practice of obstetric anesthesia in Canada in 1997. Anesthesiologists with university affiliation have very similar practices to those without university affiliations.

Epidural anesthesia was a commonly used technique for elective Cesarean section. Recently, because of the availability of non-cutting spinal needles, many institutions have changed from epidural to spinal anesthesia. The purpose of this study was to compare maternal satisfaction between epidural and spinal anesthesia for elective Cesarean section with a new satisfaction tool.We studied healthy parturients in a randomized, double-blinded pilot study in which patients were assigned to receive either epidural (n = 13) or spinal (n = 14) anesthesia for elective Cesarean section. Two and 24 hr postoperatively, patients completed a validated 22-point maternal satisfaction questionnaire and a 10-cm visual analog score (VAS) for satisfaction. Maternal satisfaction scores were compared between groups.There was no difference in demographics, complications or technical failures between groups. Mean satisfaction scores on the questionnaire (0-154) at two and 24 hr were 130.23 +/- 11.36 and 129.54 +/- 16.70 for the epidural group and 116.92 +/- 18.47 and 115.92 +/- 15.71 for the spinal group (P = 0.04 and P = 0.03 respectively). No difference in VAS scores was noted. The presence of minor side effects including pruritus contributed to the lower satisfaction in the spinal group at 24 hr.This pilot study demonstrated higher maternal satisfaction with epidural than with spinal anesthesia for elective Cesarean section. This may be related to the increased side effects caused by neuraxial morphine. The satisfaction questionnaire was able to elucidate differences not detected with a global VAS for satisfaction. Further study with a larger patient population is required to confirm these data.

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.

A new needle, 120 mm long and 26 gauge in diameter, has been introduced for subarachnoid anaesthesia. The resistance to flow through the needle was measured using a pressure monitor infusion pump and compared with the resistance to flow through a 90-mm 26-gauge needle; there was a threefold increase in resistance in the 120-mm needle compared to the 90-mm needle, which could not be explained by the difference in length alone and must reflect a decrease in the internal diameter of the long needle. This results in difficulty in identifying the subarachnoid space by backflow of cerebrospinal fluid.

A reduction in hole size for certain side-port spinal needles has been advocated in recent reports. While the influence of orifice-area reduction on the aspiration capability of the needle has been studied, the influence on the anaesthetic delivery properties is relatively unknown. As a first step in understanding the effects of hole-size reduction on anaesthetic distribution within the subarachnoid space, we studied flows emanating from isolated needles using computer simulations. Following validation of the numerical model using experimental particle visualisation, trajectories of anaesthetic particles injected through 25 G Whitacre needles of various orifice areas were computed and used to determine the orientation and rate of spread of the anaesthetic jet exiting the needle. Two factors impacting the concentration distribution were observed: the rate of spread of the anaesthetic jet increases markedly with decreasing orifice area and the jet alignment shifts toward perpendicular to the needle axis.