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PubMed2004

[Femoral nerve block as pain relief in hip fracture. A good alternative in perioperative treatment proved by a prospective study].

Almost 25% of all patients with hip fracture experience temporary confusion pre- and directly postoperatively due to trauma, advanced age, transport between units, and the use of analgesics, 35-50% of the patients suffer temporary or chronic decubitus. Analgesics often lead to nausea. A femoral nerve block can interrupt sensory impulses from the hip joint and provide complete pain relief without affecting the CNS, thus making preoperative care easier and postoperative rehabilitation can be started earlier. 80 consecutive patients with hip fracture were randomized to femoral nerve block or pharmacological treatment only. Paracetamol and tramadol were the standard analgesics used. All patients were followed up with regard to pain, duration of the block, number of analgesics doses, temporary confusion and time for postoperative mobilization. Pain was estimated by the patients using the visual analogue scale (VAS). A nerve block was performed to block the femoral nerve, the lateral femoral cutaneous nerve and the obturator nerve with 30 ml of ropivacaine 7.5 mg/ml. Mental status was evaluated with Pfeiffer-test. All patients experienced relatively intense pain on admission with an average VAS of 6. After nerve block the VAS was 2. Pain relief was the same in the control group. Pain relief was sustained for 15 hours. The time for mobilization after surgery was significantly lower, 23 hours compared to 36 for the control group. There was a lower number of patients temporarily confused in the block group compared to the control group, however no significant differences were seen. Femoral nerve block provides adequate pain relief, equivalent to pharmacological treatment in most patients. The time for postoperative mobilization was shorter and less temporary confusion was seen. There were no complications in this group, making nerve block a good alternative to traditional pharmacological preoperative treatment for patients with hip fractures.

Aged↗

PubMed2004

Lower extremity nerve blocks.

PURPOSE OF REVIEW: The purpose of this review is to present the most important recent studies into the clinical use of peripheral nerve blocks for anesthesia and postoperative analgesia of the lower limb surgery. RECENT FINDINGS: There is increasing interest in lower extremity peripheral nerve blocks because of their potential advantages and concerns over interactions of centroneuraxis blocks and anticoagulants. Several authors have studied different approaches to the blockade of peripheral nerves with their advantages or disadvantages. Continuous peripheral nerve blocks have showed prolonged analgesia and great patient satisfaction with low side effects. Recent imaging techniques (e.g. ultrasound, magnetic resonance, tomography scans) have been developed to improve the performance of lower peripheral nerve blocks. Finally, complications of these techniques have been examined. SUMMARY: Introduction of new methods and techniques are increasing and improving the use of lower peripheral nerve blocks. These techniques are gaining interest after the important increase of the lower molecular weigh heparins.

Journal Article↗

PubMed2003

Peripheral nerve block for ambulatory surgery and postoperative analgesia.

PURPOSE OF REVIEW: With this article we intend to increase the awareness of the efficiency and efficacy of peripheral nerve block as a treatment option for outpatient surgical anesthesia and postoperative home-based analgesia. RECENT FINDINGS: Current investigations have demonstrated that peripheral nerve block is associated with a superior outcome (reduced pain, nausea and vomiting) and more efficient patient turnover than general anesthesia. Continuous peripheral nerve block and patient controlled peripheral nerve block lead to further improvement in postoperative analgesia and patient satisfaction. SUMMARY: The recent advances and techniques described indicate that peripheral nerve block is both a valid and frequently a preferred option for ambulatory surgery.

Journal Article↗

PubMed2005

Anterior sciatic nerve block--new landmarks and clinical experience.

BACKGROUND: Anterior sciatic nerve blocks can be complicated by several problems. Pain can be caused by bony contacts and, in obese patients, identification of the landmarks is frequently difficult. METHODS: In a first step, 100 normal anterior-posterior pelvic X-rays were analyzed. The landmarks of the classical anterior approach were drawn on these X-rays and assessed for their sufficiency. Then, in a prospective case study, 200 consecutive patients undergoing total knee replacement were investigated. These patients received femoral and sciatic nerve catheters for postoperative pain management. Using modified anatomical landmarks, sciatic nerve catheters were inserted 5 cm distal from the insertion site of the femoral nerve block perpendicularly in the midline of the lower extremity. This midline connected the insertion site of the femoral nerve catheter to the midpoint between the medial and lateral epicondyle. Correct catheter positioning was verified by magnetic resonance imaging (MRI) in six patients. RESULTS: Evaluation of pelvic X-rays showed that puncture following the classical landmarks pointed in 51% at the lesser trochanter, in 5% medial to the lesser trochanter and in 42% directly at the femur. In the latter patients, location of the sciatic nerve would have been difficult or even impossible. Using our modified anterior approach, the sciatic nerve could be blocked in 196 patients (98%). In nine patients (4.5%) blockade of the posterior femoral cutaneous nerve failed. Vascular puncture happened in 10 (5%) and bony contact in 35 patients (17.5%). Median puncturing depth was 9.5 (7.5-14) cm. Correct sciatic nerve catheter positioning was verified in all patients who underwent MRI. CONCLUSION: Our landmarks for locating the sciatic nerve help to avoid bony contacts and thereby reduce pain during puncture. Our method reliably enabled catheter placement.

Aged↗

PubMed1995

Infraorbital nerve block in neonates for cleft lip repair: anatomical study and clinical application.

Infraorbital nerve block in neonates is not well described although it has been suggested that bilateral infraorbital nerve block is the local analgesic technique of choice for early repair of cleft lip. The purpose of this study was to determine the location of the infraorbital nerve in neonatal cadavers and to identify clinically useful landmarks. Thirty infraorbital nerves were identified in 15 neonatal cadavers with a mean weight of 2.85 (SD 0.32) kg (range 2.45-3.5 kg) via an upper buccal sulcus incision. The mean distance from the infraorbital nerve to the base of the alae nasi was 7.7 (SD 1.3) mm on the left and 7.5 (0.8) mm on the right. A line drawn from the angle of the mouth to the midpoint of the palpebral fissure measured 30.6 (1.9) mm (left) and 30.7 (1.8) mm (right). The nerve was situated approximately halfway along this line at a point 15.5 (1.5) mm (left) and 15.2 (1.4) mm (right) from the angle of the mouth. These measurements were used to perform bilateral infraorbital nerve blocks in four neonates undergoing cleft lip surgery under general anaesthesia, thereby providing analgesia with minimal risk of respiratory depression.

Bupivacaine↗

PubMed2001

Anesthetic efficacy of a combination of hyaluronidase and lidocaine with epinephrine in inferior alveolar nerve blocks.

The purpose of this prospective, randomized, double-blind study was to determine the anesthetic efficacy of a buffered lidocaine with epinephrine solution compared to a combination buffered lidocaine with epinephrine plus hyaluronidase solution in inferior alveolar nerve blocks. Thirty subjects randomly received an inferior alveolar nerve block using 1 of the 2 solutions at 2 separate appointments using a repeated-measures design. Mandibular anterior and posterior teeth were blindly pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive readings of 80 were obtained. A postoperative survey was used to measure pain and trismus. The results demonstrated 100% of the subjects had profound lip numbness with both solutions for inferior alveolar nerve blocks. The anesthetic success rates for individual teeth ranged from 20 to 80%. There were no significant differences (P > .05) between the 2 solutions. However, the combination lidocaine/hyaluronidase solution resulted in a significant increase in postoperative pain and trismus. It was concluded that adding hyaluronidase to a buffered lidocaine solution with epinephrine did not statistically increase the incidence of pulpal anesthesia in inferior alveolar nerve blocks and, because of its potential tissue damaging effect, it should not be added to local anesthetic solutions for inferior alveolar nerve blocks.

Adjuvants, Anesthesia↗

PubMed2006

[Analgesia after hip fracture repair in elderly patients: the effect of a continuous femoral nerve block: a prospective and randomised study].

INTRODUCTION: The usefulness of peripheral femoral nerve block for pain management after hip fracture has been established. This prospective and randomised study compared the analgesia effect of a continuous femoral nerve block (CF) versus two conventional analgesia procedures after hip fracture. PATIENTS AND METHODS: Patients. (n=62) scheduled for surgery under spinal anaesthesia were prospectively included. After surgery, analgesia (48 hours) was randomised: group FC (femoral catheter, anterior paravascular approach, initial bolus followed by continuous infusion of ropivacaine 0.2%), group P (iv 2 g propacetamol/6 hours), group M (sc morphine, 0.05 mg/kg per 4 hour). Intravenous morphine titration was performed, followed by subcutaneous (sc) morphine every 4 hours according to the VAS score. The primary end-point was the morphine requirements. Secondary end-points were VAS score, side effects, and mortality. RESULTS: Demographic data and surgical procedures were similar between groups. After morphine titration, the VAS pain score did not differ between groups. All patients in-group M received additional morphine. Morphine mean consumption was increased in CF group: 26 mg (5-42) versus P: 8 mg (3-12) (p=0.0001) or M: 19 mg (8-33) (p<0.006) while constipation was decreased in P group vs CF. Percentage of patients requiring no morphine was similar between P (n=6; 28%) and CF (n=6; 28%) and greater than M (n=0; 0%). Hospital discharge, cardiovascular or pulmonary complications and mortality after 6 months showed no statistical difference. CONCLUSION: Continuous femoral nerve block provided limited pain relief after hip fracture did not reduced side effects and induced an expensive cost.

Aged↗

PubMed2003

[Axillary brachial plexus block. Anatomical investigations to improve radial nerve block].

The axillary brachial plexus block is a very safe, but sometimes unreliable technique for anaesthesia of the upper extremities. Alternative methods like the infraclavicular block offer a higher success rate, but also the possibility of severe complications. We suggest a modified axillary technique with an injection site medial to the artery, evaluated by clinical experience and anatomical investigations, which could solve the problem of high failure rate, especially in the area of the radial nerve while still maintaining patient safety.

Brachial Plexus↗

PubMedDate not supplied

Continuous peripheral nerve blocks with stimulating catheters.

BACKGROUND AND OBJECTIVES: This study evaluated the efficacy of stimulating catheters used for continuous peripheral nerve blocks as a means of immediate verification and confirmation of correct catheter position. METHODS: This observational study presents our experience with 130 stimulating catheters used in 40 intersternocleidomastoid, 24 axillary, 47 femoral, and 19 lateral midfemoral sciatic nerve blocks. Placement characteristics (amperage, depth of introducer needle or catheter insertion, elicited motor responses), subsequent postoperative analgesia, and catheter position evaluated with the radiopaque dye analysis were all studied. RESULTS: Except in femoral blocks, characteristics of motor responses elicited (1 Hz, 0,1 ms) by the introducer assembly and catheter differed. The amperage required to elicit motor responses typically was higher with the catheter than with the introducer needle (1.6 [0.2 to 4 mA] v 0.5 [0.4 to 1 mA] P <.0001). The ability to elicit a motor response with the stimulating catheter correlated with successful clinical anesthesia in 124 cases. Opacified radiography showed no aberrant position in these cases. Three catheters for upper limb block failed to stimulate, provided poor anesthesia, and had radiologic evidence of aberrant position. Even though they failed to stimulate, 3 catheters for sciatic block functioned well, and the opacified radiography showed correct position. CONCLUSION: The ability to electrostimulate nerves using an in situ catheter increases success rate in catheter placement for continuous peripheral nerve blocks. Further controlled investigations are necessary to compare this technique with more conventional methods in terms of cost and utility for various peripheral nerve blocks.

Adult↗

PubMed2006

[Perioperative analgesia with continuous peripheral nerve blocks in children].

Recently, regional anaesthesia in children has generated increasing interest. But single injection techniques have a limited duration of postoperative analgesia. Then, continuous peripheral nerve blocks have taken an important position in the anaesthetic arsenal, allowing an effective, safe and prolonged postoperative pain management. As adults, indications for continuous peripheral nerve blocks depend on the analysis of individual benefits/risks ratio. Main indications are intense postoperative pain surgical procedures, with or without postoperative rehabilitation, and complex regional pain syndrome. Contraindications to these procedures are rather similar to those in adults, plus parental and/or children refusal. Continuous peripheral nerve blocks are usually performed under general anaesthesia or sedation in children, and require appropriate equipment in order to decrease the risk of nerve injury. New techniques, such as transcutaneous nerve stimulation or ultrasound guidance, appeared to facilitate nerve and plexus approach identification in paediatric patients. Nevertheless, continuous peripheral nerve block may theoretically mask a compartment syndrome after trauma surgical procedures. Finally, ropivacaine appears to be the most appropriate drug for continuous peripheral nerve blocks in children, requiring low flow rates and concentrations of local anaesthetic. These techniques may facilitate early ambulation by an improved pain management or even postoperative analgesia at home with disposable pumps. One might infer from the current review that excellent pain relief coupled with a reduction of side effects would contribute to improve the quality of life and to decrease the frequency of disabling behavioural modifications in children, sometimes psychologically injured by hospital stay and postoperative pain.

Amides↗

PubMed1999

Ropivacaine or 2% mepivacaine for lower limb peripheral nerve blocks. Study Group on Orthopedic Anesthesia of the Italian Society of Anesthesia, Analgesia, and Intensive Care.

BACKGROUND: Intra- and postoperative clinical properties of sciatic-femoral nerve block performed with either ropivacaine at different concentrations or mepivacaine have been evaluated in a multicenter, randomized, blinded study. METHODS: Adult patients scheduled for foot and ankle surgery were randomized to receive combined sciatic-femoral nerve block with 225 mg of either 0.5% (n = 83), 0.75% (n = 87), or 1% (n = 86) ropivacaine, or with 500 mg of 2% mepivacaine (n = 84). A thigh tourniquet was used in all patients. Onset time, adequacy of surgical anesthesia, time to offset of nerve block, and time until first postoperative requirement for pain medication were evaluated by a blinded observer. RESULTS: The adequacy of nerve block was similar in the four treatment groups (the ratios between adequate:inadequate: failed blocks were 74:9:0 with 0.5% ropivacaine, 74:13:0 with 0.75% ropivacaine, 78:8:0 with 1% ropivacaine, and 72:12:0 with 2% mepivacaine). The onset of the block was slower with 0.5% ropivacaine than with other anesthetic solutions (P < 0.001). Regardless of the concentration, ropivacaine produced a longer motor blockade (10.5+/-3.8 h, 10.3+/-4.3 h, and 10.2+/-5.1 h with 0.5%, 0.75%, and 1% ropivacaine, respectively) than with mepivacaine (4.3+/-2.6 h; P < 0.001). The duration of postoperative analgesia was shorter after mepivacaine (5.1+/-2.7 h) than after ropivacaine (12.2+/-4.1 h, 14.3+/-5 h, and 14.5+/-3.4 h, with 0.5%, 0.75%, or 1% ropivacaine, respectively; P < 0.001). Pain relief after 0.5% ropivacaine was 14% shorter than 0.75% or 1% ropivacaine (P < 0.05). During the first 24 h after surgery, 30-37% of patients receiving ropivacaine required no analgesics compared with 10% of those receiving mepivacaine (P < 0.001). CONCLUSIONS: This study suggests that 0.75% ropivacaine is the most suitable choice of local anesthetic for combined sciatic-femoral nerve block, providing an onset similar to mepivacaine and prolonged postoperative analgesia.

Adult↗

PubMedDate not supplied

Femoral nerve block in knee joint surgery.

Assessment is made of the effectiveness of femoral nerve block, administered either before or after surgery, in supplementing postoperative analgesia for knee joint (anterior cruciate) reconstruction surgery. Femoral nerve block, performed before surgery, with Bupivacaine 0.5%, reduced intramuscular opiate administration by 80% in the recovery room and 40% in the first 24 postoperative hours. An effective and rapidly performed technique for femoral nerve block is described.

Adult↗

PubMed2005

Complications of fluoroscopically guided extraforaminal cervical nerve blocks. An analysis of 1036 injections.

BACKGROUND: A number of serious complications associated with fluoroscopically guided extraforaminal cervical nerve blocks have been reported in the literature. The purpose of the present study was to determine the rate of complications associated with these blocks and to determine whether needle positioning during the procedure affected the prevalence of complications at one institution. METHODS: Between October 1999 and June 2003, we performed 1036 fluoroscopically guided extraforaminal cervical nerve blocks in 844 patients. Plain radiographs documenting the procedure were made as part of the standard quality-assurance protocol. An independent observer who was uninvolved with the procedures reviewed a prospectively kept database on all patients. We subsequently reviewed the patient records to identify complications. RESULTS: There were no catastrophic complications such as vessel damage, paralysis, or death. Overall, fourteen patients (1.66%) had a minor complication in association with the procedure. With the numbers available, the rate of complications associated with pdeep injection (798 blocks) was not significantly different from that associated with shallow injection (238 blocks) (1.89% compared with 0.84%). However, the rate of complications associated with anterior placement of the needle tip (thirty-three blocks) was higher than that associated with ideal placement of the needle tip (904 blocks) (6.06% compared with 1.55%) (p = 0.04). CONCLUSIONS: No catastrophic complications occurred in this series of 1036 nerve blocks. We found that the medial-lateral needle depth as seen on frontal-view radiographs was not associated with complications, although the anterior positioning of the needle as seen on lateral-view radiographs was associated with minor complications. Our results suggest that, with our technique, cervical nerve blocks are relatively safe procedures.

Anti-Inflammatory Agents↗

PubMedDate not supplied

Computed tomography-guided pudendal nerve block. A new diagnostic approach to long-term anoperineal pain: a report of two cases.

OBJECTIVE: To show the value of computed tomography (CT) in selectively blocking the pudendal nerve in patients with long-term anogenital pain of uncertain etiology. We report a technique to selectively block the pudendal nerve using CT guidance in 2 patients with long-term anogenital pain. CASE REPORT: In 1 patient, a competitive cyclist, the diagnosis of pudendal neuralgia was substantiated by blocking the nerve under CT. The procedure relieved the pain for approximately 24 hours. In the other patient, pudendal nerve block produced perineal analgesia but no pain relief. Superior hypogastric plexus block relieved the pain significantly for about 4 weeks on 2 separate occasions, suggesting sympathetically maintained pain. CONCLUSION: The use of CT to guide the procedure allowed precision in performing the procedure and in making a differential diagnosis.

Adult↗

PubMed2003

Suprascapular nerve block or a piroxicam patch for shoulder tip pain after day case laparoscopic surgery.

BACKGROUND AND OBJECTIVE: The reported incidence of shoulder tip pain following laparoscopic surgery varies from 35 to 63%. This study evaluated the analgesic efficacy of either performing a prophylactic suprascapular nerve block with bupivacaine or applying a piroxicam patch to the skin over both shoulders for the relief of shoulder tip pain after laparoscopy. METHODS: Sixty healthy informed female patients were randomly assigned to one of three groups: (a) a control group (n = 20), no treatment; (b) a suprascapular nerve block group (n = 20) in which a bilateral suprascapular nerve block was performed before induction of anaesthesia with 5 mL 0.5% bupivacaine with epinephrine; and (c) a piroxicam patch group (n = 20) in which a 48 mg piroxicam patch on the skin of each shoulder was applied before induction of anaesthesia. All patients received a total intravenous anaesthesia technique with propofol, fentanyl and vecuronium. Shoulder tip and wound pain were recorded on a visual analogue pain scale at five time intervals for 24 h after surgery. RESULTS: A total of 80% of patients in the control group, 75% in the suprascapular nerve block group and 45% in the piroxicam patch group complained of shoulder tip pain during the recording period (P < 0.05). The scores for shoulder tip pain in the piroxicam patch group were significantly lower compared with the control group at 3, 6 and 12 h, and compared with the suprascapular nerve block group at 6 and 12 h. The need for analgesics was also significantly lower in the piroxicam patch group compared with the other two groups. CONCLUSIONS: Prophylactic piroxicam patches are effective and safe for the relief of shoulder tip pain after laparoscopy. Bilateral suprascapular nerve block is not effective in this setting.

Administration, Cutaneous↗

PubMed2000

Unilateral spinal anesthesia or combined sciatic-femoral nerve block for day-case knee arthroscopy. A prospective, randomized comparison.

BACKGROUND: To evaluate the time required to achieve surgical block and fulfill standardized discharge criteria in outpatients receiving knee arthroscopy with either unilateral spinal anesthesia or combined sciatic-femoral nerve block. METHODS: After a standard midazolam/ketoprofen premedication and baseline measurement of cardiovascular parameters, 50 ASA physical status I-II patients scheduled for elective outpatient knee arthroscopy were randomized to receive unilateral spinal anesthesia with 8 mg of 0.5% hyperbaric bupivacaine injected without barbotage through a 25-gauge Whitacre spinal needle (group USA, n = 25), or combined sciatic-femoral nerve block with 25 ml of 2% mepivacaine (15 ml for femoral nerve block and 10 ml for sciatic nerve block) (group SFNB, n = 25). Times from local anesthetic injection to achievement of surgical block defined as the presence of adequate motor (complete motor blockade of the operated limb in the USA group and inability to move the ankle and the knee of the operated limb in the SFNB group) and sensory (loss of pinprick sensation at T12 on the operated side in the USA group, or in the femoral and sciatic nerves distribution in the SFNB group) blocks was recorded. Times to block resolution, urination, unassisted ambulation, and readiness to home discharge were also recorded by a blind observer, as well as occurrence of untoward events during surgery. RESULTS: Surgical block was achieved in 15 +/- 6 min in group USA and 16 +/- 6 min in group SFNB (p = NS). No differences in hemodynamic undesired effects and success rate were observed. Even though USA patients showed a faster time to ambulation (166 +/- 44 min versus 217 +/- 49 min, p = 0.002) and later urination (240 +/- 90 min versus 145 +/- 36 min, p = 0.0001) than SFNB group, no differences in home discharging were reported (246 +/- 98 min versus 211 +/- 77 min, respectively). Bladder catheterization was required in 2 patients of USA group only; however, no patient was admitted to the hospital because of urinary retention. CONCLUSIONS: In outpatient knee arthroscopy, a combined sciatic-femoral nerve block with 2% mepivacaine provides similarly successful anesthesia with onset times and home discharge similar to those provided by unilateral spinal anesthesia.

Adolescent↗

PubMed2001

Tapping with peripheral nerve block. a role for tactile feedback in the timing of movements.

This study examines the impact of peripheral nerve block, that is, the elimination of tactile feedback on synchronization performance. In a tapping experiment in which subjects were instructed to tap in synchrony with an auditory pacing signal, three different tasks were studied under conditions with and without peripheral nerve block: standard tapping with tactile contact, isometric tapping, and contact-free tapping. In addition, the maximum tapping rate was registered both with and without peripheral nerve block. It was found that the anticipatory error, usually observed in synchronization tasks, was affected by the peripheral nerve block in the standard tapping and the isometric tapping task. In both tasks, local anesthesia led to an increase in asynchrony between the pacing signal and the tap. Performance remained unimpaired in those tasks in which tactile information was assumed to play a minor role (maximum tapping rate and contact-free tapping). The results clearly demonstrate the importance of tactile feedback for the timing of movements. The predictions of a model assuming a strong correlation between the amount of sensory feedback and the size of the negative asynchrony in synchronization tasks were examined and discussed.

Adult↗

PubMed2001

[Relevance of nerve blocks in treating and diagnosing low back pain--is the quality decisive?].

Diagnostic nerve blocks: The popularity of neural blockade as a diagnostic tool in painful conditions, especially in the spine, is due to features like the unspecific character of spinal pain, the irrelevance of radiological findings and the purely subjective character of pain. It is said that apart from specific causes of pain and clear radicular involvement with obvious neurological deficits and corresponding findings of a prolapsed disc in MRI or CT pictures, a diagnosis of the anatomical cause of the pain can only be established if invasive tests are used [5]. These include zygapophyseal joint blocks, sacroiliacal joint blocks, disc stimulation and nerve root blocks. Under controlled conditions, it has been shown that among patients with chronic nonradicular low back pain, some 10-15% have zygapophyseal joint pain [58], some 15-20% have sacroiliacal joint pain [36, 59] and 40% have pain from internal disc disruption [60]. The diagnostic use of neural blockade rests on three premises. First, pathology causing pain is located in an exact peripheral location, and impulses from this site travel via a unique and consistent neural root. Second, injection of local aneasthetic totally abolishes sensory function of intended nerves and does not affect other nerves. Third, relief of pain after local anaesthetic block is attributable solely to block of the target afferent neural pathway. The validity of these assumptions is limited by complexities of anatomy, physiology, and psychology of pain perception and the effect of local anaesthetics on impulse conduction [28]. Facet joints: The prevalence of zygapophyseal joint pain among patients with low back pain seems to be between 15% and 40% [62], but apparently only 7% of patients have pure facet pain [8, 29]. Facet blockade is achieved either by injection of local anaesthetic into the joint space or around the medial branches of the posterior medial rami of the spinal nerves that innervate the joint. There are several problems with intraarticular facet injections, mainly failure to enter the joint capsule and rupture of the capsule during the injection [11]. There is no physiological means to test the adaequacy of medial nerve block, because the lower branches have no cutaneous innervation. Medial ramus blocks (for one joint two nerves have to be infiltrated) are as effective as intraarticular joint blocks [37]. Reproducibility of the test is not high, the specifity is only 65% [61]. For diagnosis of facet pain fluoroscopic control is always necessary as in the other diagnostic blocks. Sacroiliacal joint: Definitely the sacroiliacal joint can be the source of low back pain. Stimulation of the joint by injection in subjects without pain produces pain in the buttock, in the posterior thigh and the knee. There are many clinical tests which confirm the diagnosis, but the interrater reliability is moderate [53]. Intraarticular injection can be achieved in the lower part of the joint with fluoroscopic guidance only, but an accurate intraarticular injection, which is confirmed by contrast medium, even at this place is often difficult. It is not clear whether intraarticular spread is necessary to achieve efficacy. Discography: Two primary syndromes concerning the ventral compartment have been described: anular fissures of the disc and instability of the motion segment. In the syndrome of anular tear, leakage of nucleus pulposus material into the anulus fibrosus is considered to be the source of pain. The studies of Vaharanta [71] and Moneta [41] show a clear and significant correlation between disc pain and grade 3 fissures of the anulus fibrosus. intervertebral discs are difficult to anaesthetize. Intradiskal injections of local anaesthetics may succeed in relieving the patient's pain, but such injections are liable to yield false negative results if the injected agent fails to adequately infiltrate the nerve endings in the outer anulus fibrosus that mediate the patient's pain. In the majority of cases MRI provide adaequate information, but discography may be superior in early stages of anular tear and in clarifying the relation between imaging data and pain [71]. Selective spinal nerve injection: In patients with complicated radiculopathy, the contribution of root inflammation to pain may not be certain, or the level of pathology may be unclear. Diagnostic root blocks are indicated in the following situations: atypical topography of radicular pain, disc prolapses or central spinal stenosis at more than one level and monoradicular pain, lateral spinal stenosis, postnucleotomysyndrome. Injection of individual spinal nerves by paravertebral approach has to be used to elucidate the mechanism and source of pain in this unclear situations. The premise is that needle contact will identify the nerve that produces the patient's characteristic pain and that local anaesthetic delivered to the pathogenic nerve will be uniquely analgesic. Often, this method is used for surgical planning, such as determining the site of foraminotomy. All diagnostic nerve root blocks have to be done under fluoroscopic guidance. Pain relief with blockade of a spinal nerve cannot distinguish between pathology of the proximal nerve in the intervertebral foramen or pain transmitted from distal sites by that nerve. Besides, the tissue injury in the nerve's distribution and neuropathic pain (for instance as a result of root injury) likewise would be relieved by a proximal block of the nerve. Satisfactory needle placement could not be achieved in 10% of patient's at L4, 15% at L5 and 30% at S1 [28]. The positive predictive value of indicated radiculopathy confirmed by surgery ranged between 87-100% [14, 22]. The negative predictive value is poorly studied, because few patients in the negative test group had surgery. Negative predictive values were 27% and 38% of the small number of patients operated on despite a negative test. Only one prospective study was published, which showed a positive predictive value of 95% and an untested negative predictive value [66]. Some studies repeatedly demonstrated that pain relief by nerve root block does not predict success by neuroablative procedures, neither by dorsal rhyzotomy nor by dorsal gangliectomy [46]. Therapeutic nerve blocks - facet joints: Intraarticular injection of steroids offer no greater benefit than injections of normal saline [8, 15] and long lasting success is lacking. In this case, a denervation of the medial branches can be considered. To date three randomized controlled studies of radiofrequency facet denervation have been published. One study [20] reported only modest outcomes and its results remained inconclusive, another study [72] with a double blind controlled design showed some effects in a small selected group of patients (adjusted odds ratio 4.8) 3, 6 and 12 months after treatment, concerning not only reduction of pain but alleviating functional disability also. The third study (34a) showed no effect 3 months after treatment. Discogenic pain: Intradiscal radiofrequency lesions, intradiscal injections of steroids and phenol have been advocated, but there are no well controlled studies. Just recently, intradiscal lesion and denervation of the anulus has been described with promising results, but a randomized controlled study is lacking up to now [31, 55]. Epidural Steroids: Steroids relieve pain by reducing inflammation and by blocking transmission of nociceptive C-fiber input. Koes et al. [33] reviewed the randomized trials of epidural steroids: To date, 15 trials have been performed to evaluate the efficacy, 11 of which showed method scores of 50 points (from 100) ore more. The trials showed inconsistent results of epidural injections. Of the 15 trials, 8 reported positive results and 7 others reported negative results. Consequently the efficacy of epidural steroid injections has not yet been established. The benefits of epidural steroid injections seem to be of short duration only. Future efficacy studies, which are clearly needed, should take into account the apparent methological shortcomings. Furthermore, it is unclear which patients benefit from these injections. In our hands the injection technique can be much improved by fluoroscopic guidance of the needle, with a prone position of the patient, and lateral injection at the relevant level and with a small volume (1-2 ml) and low dose of corticosteroid (20 mg triamcinolone in the case of a monoradicular pain, for example). In the case of epidural adhesions in postoperative radicular pain [50], the study of Heafner showed that the additional effect of hyaloronidase and hypertonic saline to steroids was minimal. In our hands there was no effect in chronic radicular pain 3 months after the injection.

Humans↗