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At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Anatomic considerations for sciatic nerve block in the popliteal fossa through the lateral approach.

BACKGROUND AND OBJECTIVES: The disadvantage of the classic posterior approach to block of the sciatic nerve at the knee level (popliteal nerve block [PNB]) is the need to position a patient in the prone position for performance of the block. In this study on cadavers, a lateral approach to the popliteal nerve in the supine position was investigated, and some anatomic considerations of relevance to popliteal nerve block were addressed. METHODS: In 19 cadaver right legs, the lateral approach to PNB was simulated with a needle, introduced in the groove between the biceps femoris and vastus lateralis muscles 7 cm above the knee, at either 30 degrees or 60 degrees relative to the horizontal plane, and 1 mL of dye solution was injected through the needle. After dissection of the popliteal fossa, the position of the solidified bolus of dye in relation to the popliteal nerve was determined. Additionally, the dye was injected into the popliteal nerve sheath, and the spread of the dye and continuity of the sheaths were determined. RESULTS: In 10 legs, the lateral approach was attempted at a 30 degrees angle and in 9 legs at a 60 degrees angle. The solidified injectates at 30 degrees were closely distributed anterolaterally to the nerve, while injectates at 60 degrees tended to be further from the nerve and scattered along its posterolateral aspect (P = .02). The dye injected into the nerve sheaths traveled 5 to 10 cm within the sheath, surrounding both main divisions of the popliteal nerve, the tibial and the common peroneal nerve. CONCLUSION: A lateral approach to the popliteal nerve with insertion of the needle at a 30 degrees angle relative to the horizontal plane results in predictable approximation of the needle tip to the popliteal nerve. The results also suggest the existence of a continuous neural sheath encompassing the popliteal nerve and its main branches. This may have clinical implications similar to those in perivascular neuronal block.

Dissection↗
PubMedDate not supplied

Abdominal pain and alcohol celiac plexus nerve block.

Alcohol celiac plexus nerve blocks were done in 100 patients, of whome 97 had intractable abdominal pain from cancer. In most cases, an initial diagnositc block with bupivacaine was followed by the therapeutic block performed by injecting 50 ml of 50 percent ethyl alcohol. Good to excellent pain relief occurred in 94 percent of patients. Fourteen blocks were repeated for recurrent pain. Life duration ranged from 2 days to 14 months after the block. Complications and side effects were infrequently seen but did include a 10 percent incidence of postural hypotension and 1 case of partial leg paralysis. This block is remarkably safe as well as effective and should be employed more frequently.

Abdomen↗
PubMedDate not supplied

Plasma concentrations after high doses of mepivacaine with epinephrine in the combined psoas compartment/sciatic nerve block.

A combination of psoas compartment block and sciatic nerve block was performed with a total dose of 731.5 mg mepivacaine (55 ml, 1.33%) with epinephrine (1:600,000) in patients scheduled for orthopedic surgery on one leg. In 20 patients, arterial blood samples were collected at timed intervals over a 6-hour period to determine the mepivacaine plasma concentration. In all patients, good sensory and motor blocks were obtained and no analgesics were required during surgery. Despite the high dose of mepivacaine, the plasma concentrations stayed below 6.0 micrograms/ml, with one exception, although no clinical signs of local anesthetic toxicity were observed. Plasma pharmacokinetic variables of mepivacaine were as follows: Cmax: 4.22 mg.l-1 (SD, 1.28); Tmax: 0.99 hours (SD, 0.76); T1/2: 3.25 hours (SD, 1.12); CL 0.55 1.hour-1.kg-1.

Adult↗
PubMed1977

Spinal nerve block. A diagnostic test in sciatica.

The cause of sciatica has been studied by blocking spinal nerves of the lumbosacral plexus in intervertebral foramina. The nerve, which is singled out with the aid of an image intensifier, is injected with 1 ml of 1 per cent Xylocain. If the Xylocain injection eliminates the sciatic pain, the surgeon may be confident that a true nerve-root compression is involved, and he can then explore as far as he finds necessary. The correlation between the site of compression and the level indicated by the test was confirmed by operation in 19 patients.

Adult↗
PubMed1998

AANA Journal Course: update for nurse anesthetists--femoral nerve block and 3-in-1 block in anesthesia.

Femoral nerve blocks and 3-in-1 blocks are simple and useful alternatives to other regional or general anesthetic techniques for selected surgeries. These blocks also may provide postoperative analgesia that may be a useful alternative to epidural or parenteral analgesia. Understanding the techniques of blockade, its appropriate applications, and the relevant anatomy may provide the anesthetist with a valuable alternative.

Contraindications↗
PubMed2003

Lingual nerve damage due to inferior alveolar nerve blocks: a possible explanation.

BACKGROUND: An explanation for the predominance of injuries to lingual nerves over those to inferior alveolar nerves as a result of inferior alveolar nerve blocks may be due to the nerves' fascicular pattern. A unifascicular nerve may be injured more easily than a multifascicular nerve. METHODS: The authors unilaterally dissected lingual and inferior alveolar nerves from 12 cadavers. They cut the specimens 2 millimeters above the lingula for both the lingual nerve and inferior alveolar nerve and opposite the site of the middle of the third molar for the lingual nerve, and they counted the number of fascicles at each site. RESULTS: For the lingual nerve at the lingula, the mean number of fascicles was three (range, one to eight). Four of the 12 nerves (33 percent) were unifascicular at this point. Opposite the third molar, the lingual nerve had a mean of 20 fascicles (range, six to 39). In every case, there were more fascicles in the third molar region than above the lingula in the same nerve. At the lingula, the inferior alveolar nerve had a mean of 7.2 fascicles (range, three to 14). CONCLUSION: This study may explain the observation that when an inferior alveolar nerve block causes permanent nerve impairment, the lingual nerve is affected about 70 percent of the time and the inferior alveolar nerve is affected only 30 percent of the time. In 33 percent of cases, the lingual nerve had only one fascicle at the lingula; a unifascicular nerve may be injured more easily than a multifascicular one. CLINICAL IMPLICATIONS: There is no known way to avoid the remote possibility of nerve damage resulting from an inferior alveolar nerve block. The lingual nerve may be predominantly affected because of its fascicular pattern.

Anesthesia, Dental↗
PubMed1985

Sciatic nerve block in the popliteal fossa with atraumatic needles and nerve stimulation.

Seventy-three popliteal sciatic nerve blocks were performed with the help of a nerve stimulator and teflon-sheathed needles in order to assess the usefulness and the reliability of the method in orthopaedic surgery. After a careful description of the technique, the results and complications are presented: successful blocks = 89%; supplementary local anesthesia = 5.5%; general anesthesia = 5.5%. The indications, the results and the technique of the popliteal sciatic nerve block are discussed. The benefits brought by the use of atraumatic needles and nerve stimulators in regional anesthesia are outlined.

Adult↗
PubMedDate not supplied

Femoral nerve block with 0.25% or 0.5% bupivacaine improves postoperative analgesia following outpatient arthroscopic anterior cruciate ligament repair.

BACKGROUND AND OBJECTIVES: Femoral nerve block is effective in reducing postoperative pain after inpatient knee surgery. We studied its efficacy compared with standard analgesia following outpatient anterior cruciate ligament repair, including the duration of analgesia and the effect of different concentrations of bupivacaine. METHODS: After Institutional Review Board approval and informed consent, we prospectively randomized patients to receive, in a blinded fashion, either a sham block, a femoral nerve block with 25 mL 0.25% bupivacaine, or with 25 mL 0.5% bupivacaine after anterior cruciate ligament repair under epidural anesthesia. Verbal analog pain scores were evaluated by a blinded observer at 20 and 40 minutes after injection. Patients with pain >4 (out of 10) were assessed for the presence of a block and offered a supplemental block if no anesthesia was present at either evaluation. By prospective agreement, any study group with 6 failures was excluded from further recruitment. After discharge, patients recorded pain scores and analgesic consumption in a diary, and estimated the time at which they perceived that analgesia and sensory block from the femoral nerve block resolved, based on an increase in pain, sensation, and strength in the leg. RESULTS: In the sham block group, 6 of 12 patients reported inadequate analgesia in the postanesthesia care unit (4 at 20 minutes, 2 at 40 minutes; greater than other groups, P <.003) and were excluded from further study. Patients with sham blocks had higher pain scores 20 minutes after the block, and requested intravenous analgesia more often. Bupivacaine 0.25% and 0.5% provided 23.2 +/- 7 and 25.7 +/- 11 hours of analgesia, respectively. CONCLUSIONS: Femoral nerve block with 0.25% bupivacaine contributes significantly to multimodal postoperative analgesia in the immediate postoperative period following outpatient anterior cruciate ligament repair. Both doses of bupivacaine studied provided analgesia for the first night after surgery.

Adult↗
PubMed1998

Inhibition of physiologic stress responses by regional nerve block during orthognathic surgery under hypotensive anesthesia.

OBJECTIVE: The purpose of this study was to investigate the inhibitory effects of nerve block on stress responses during orthognathic surgery involving general anesthesia with induced hypotension. STUDY DESIGN: Fourteen patients (ASA-1) undergoing Le Fort 1 osteotomy and sagittal splitting mandibular osteotomy were divided into 2 groups: a block group (with maxillary and mandibular nerve blocks; n = 7) and a non-block group (without nerve blocks; n = 7). Anesthesia was maintained with N2O-O2 and isoflurane (block group, 0.8%; non-block group, 1.2%). Adenosine triphosphate was administered for induced hypotension. Observed variables included hemodynamic parameters and fluctuations and adenosine triphosphate dose. Plasma norepinephrine concentrations and blood gases were observed in the block group. RESULTS: More stable hemodynamics, with a lower adenosine triphosphate dose as well as negligible changes in norepinephrine concentrations and blood gases, were obtained in the block group. CONCLUSIONS: The stress responses were inhibited by nerve blocks combined with low-concentration inhalation anesthesia during adenosine triphosphate-induced hypotension. The adenosine triphosphate requirement was reduced under stable hemodynamics achieved with nerve blocks.

Adenosine Triphosphate↗
PubMed2002

Failure of inferior alveolar nerve block: exploring the alternatives.

BACKGROUND: Achieving proper anesthesia is imperative to performing most dental procedures. The conventional inferior alveolar nerve block is the most commonly used nerve block technique. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. OVERALL: The authors explore the reasons why the conventional inferior alveolar nerve block fails and describe several alternate techniques. They also present the protocol used in their office to achieve mandibular anesthesia. CONCLUSIONS: Several alternatives to the inferior alveolar nerve block are available. Clinicians should investigate them, rather than repeat the inferior alveolar nerve block after it has failed. Practice Implications. Mastering anesthetic techniques maximizes success in the dental office. It enables clinicians to provide better and more comfortable treatment to patients.

Alveolar Process↗
PubMed1999

Electrically elicited blink reflex in horses with trigeminal and facial nerve blocks.

OBJECTIVE: To reassess reference values for the components of the electrically induced blink reflex, document reference values for facial motor nerve conduction velocity, and demonstrate usefulness of the blink reflex as a diagnostic tool in peripheral facial and trigeminal nerve dysfunction in horses. ANIMALS: 10 healthy adult horses (8 males, 2 females) without neurologic abnormalities. PROCEDURE: Blink reflex tests were performed by electrical stimulation of the supraorbital nerve and facial (auriculopalpebral) nerve. Reflex and direct muscle-evoked potentials of the orbicularis oculi muscles were recorded from concentric needle electrodes inserted bilaterally in these muscles. Supraorbital and auriculopalpebral nerve blocks were performed by lidocaine hydrochloride injections. RESULTS: Supraorbital nerve stimulation elicited 2 or 3 ipsilateral and 1 contralateral reflex muscle potential in the orbicularis oculi muscles. Auriculopalpebral nerve stimulation elicited a direct and a reflex potential in the ipsilateral orbicularis oculi muscle. After left supraorbital nerve block, no responses could be elicited ipsilaterally or contralaterally upon stimulation of the blocked nerve, but bilateral responses were obtained upon stimulation of the right supraorbital nerve. After right auriculopalpebral nerve block, no responses were recorded from the right orbicularis oculi muscle upon stimulation of left or right supraorbital nerves. CONCLUSIONS AND CLINICAL RELEVANCE: Reference values for the components of the blink reflex and facial motor nerve conduction velocity will allow application of these tests to assist in the diagnosis of equine neurologic disorders involving the trigeminal and facial nerves, the brainstem, and the cranial end of the cervical segment of the spinal cord. This study reveals the usefulness of the blink reflex test in the diagnosis of peripheral trigeminal and facial nerve dysfunction in horses.

Animals↗
PubMed2007

A randomized controlled trial comparing a fascia iliaca compartment nerve block to a traditional systemic analgesic for femur fractures in a pediatric emergency department.

STUDY OBJECTIVE: We determine whether a fascia iliaca compartment nerve block can provide superior pain management compared with intravenous morphine sulfate for the initial pain management of femur fracture patients presenting to a pediatric emergency department. The primary outcome measured is pain scores; a difference of 15% in scores assessed at 30 minutes from the study's baseline pain management is considered clinically meaningful. Secondary outcomes include the duration of analgesia, the need for additional medications, adverse events, nerve block complications, and satisfaction scores. METHODS: This was a prospective, randomized, unblinded, controlled trial conducted on children aged 15 months to 18 years with acute femur fractures, presenting to a free-standing, tertiary care children's hospital. Patients were randomized to receive intravenous morphine sulfate or a fascia iliaca compartment nerve block using ropivacaine (Naropin). Pain scores (Children's Hospital of Eastern Ontario Pain Scale [CHEOPS]; Face, Legs, Activity, Cry and Consolability Pain Scale; Faces Pain Scale) were recorded at initial analgesic administration (baseline), at 5, 10, 15, 30, and 60 minutes, and then hourly up to 6 hours from baseline by trained nursing observers and research assistants. RESULTS: Fifty-five patients, 26 in the fascia iliaca compartment nerve block group and 29 in the morphine sulfate group, ranged in age from 16 months to 15 years (median 5.7 years). Baseline mean CHEOPS scores were similar: 9.4 fascia iliaca compartment nerve block and 9.5 morphine sulfate. Mean CHEOPS scores at 30 minutes after initial treatment were 5.87 for fascia iliaca compartment nerve block and 7.54 for morphine sulfate, with a difference of 1.67, which corresponds to an 18% (95% confidence interval [CI] 8% to 27%) difference in pain reduction between the 2 groups, according to the average baseline score of 9.45. Similar lower pain scores were observed in the fascia iliaca compartment nerve block group as early as 10 minutes from baseline and throughout the 6-hour duration of the study. In comparing the entire 6-hour CHEOPS pain scores, patients who received a fascia iliaca compartment nerve block showed lower scores by approximately 15% (95% CI 6% to 24%) compared to patients who received morphine sulfate. Median duration of analgesia was longer in the fascia iliaca compartment nerve block group compared with that in the morphine sulfate group (313 minutes [95% CI 154 to 360 minutes] versus 60 minutes [95% CI 10 to 255 minutes]). Fewer additional medications were given to patients who received the fascia iliaca compartment nerve block. No complications from the nerve block occurred. Satisfaction scores were higher with the fascia iliaca compartment nerve block among the medical staff. CONCLUSION: Fascia iliaca compartment nerve block provided clinically superior pain management compared with intravenous morphine sulfate at 30 minutes from baseline and throughout the initial 6 hours of medical treatment of children 16 months to 15 years who had isolated acute femur fractures. The results of this study, however, may be inflated by the nonblinding of the pain observers. Despite this potential bias, the fascia iliaca compartment nerve block should be considered as a valuable procedure in managing the pain commonly observed in these injured children.

Adolescent↗
PubMed2006

Use of a nerve stimulator does not improve the efficacy of ultrasound-guided supraclavicular nerve blocks.

OBJECTIVE: To evaluate the efficacy of nerve stimulation as an adjunct to ultrasound-guided supraclavicular nerve blocks. DESIGN: Prospective database review. SETTING: Tertiary-care medical center. MEASUREMENTS: The records of 94 consecutive adult patients requiring surgery below the elbow and consenting to receive regional anesthesia were studied. The focus of this study was on supraclavicular nerve block using ultrasound guidance for nerve identification and needle localization. A nerve stimulator with a motor response lower than 0.5 mA was used for confirmation of findings. An ultrasound image was considered adequate if two trunks of the brachial plexus were visualized and if the needle was completely seen on the long axis. A successful block was defined as one that sufficed as the sole anesthetic without conversion to general anesthesia. Motor and sensory examination findings on the upper extremity were also evaluated. RESULTS: 74 patients had an adequate ultrasound image. Of the 64 patients with a positive motor response, 88% had a successful block, as compared with 90% of the 10 patients without a motor response (relative risk, 1.09; 95% confidence interval, 0.79-1.51; P = 0.52). Neither multivariate correction for baseline characteristics nor inclusion of the 20 patients with inadequate ultrasound images changed the results. CONCLUSION: For adequately imaged ultrasound-guided supraclavicular nerve blocks, a positive motor response to nerve stimulation does not increase the success rate of the block. In addition, the high false-negative rate suggests that these blocks are usually effective, even in the absence of a motor response. Nerve stimulation as an adjunct to ultrasound guidance may have a limited role.

Anesthesia, Conduction↗
PubMed2006

The effect of age on sciatic nerve block duration.

The physiologic changes that occur with advancing age and their effect on the duration of peripheral nerve blocks have yet to be defined. We prospectively studied the duration of sciatic nerve block using mepivacaine in younger and older patients. Eighty ASA physical status I-III patients, aged 18-35 (n = 40) or 55-80 (n = 40) yr, having outpatient knee arthroscopy with a femoral block and a standardized sciatic nerve block were enrolled; 37 in each group completed the study. All patients received a Labat sciatic nerve block using 20 mL of 1.0% mepivacaine with 0.1 mEq/mL sodium bicarbonate and 1:400,000 (2.5 microg/mL) epinephrine and a femoral nerve block. The duration of sensory block (sensation of pinprick, temperature, and vibration), motor block (plantar and dorsi flexion), and complete sensory and motor block in the sciatic nerve distribution of the operative extremity were measured. The time for complete return of both sensory and motor function was longer in the older group, 329 +/- 47 min compared with 306 +/- 46 min (mean +/- sd) in the younger group (P = 0.04). The difference was small under the conditions of this study and would not be perceived clinically. Age also increased the time to return of vibratory sensation (younger = 292 +/- 58 min, older = 257 +/- 50 min; P = 0.007). The other measurements did not differ between groups. We conclude that age may affect peripheral nerve blocks and that more investigation is needed to determine the pharmacologic, physiologic, and chronologic factors behind these findings.

Adolescent↗
PubMedDate not supplied

An observational study of combined continuous lumbar plexus and single-shot sciatic nerve blocks for post-knee surgery analgesia.

BACKGROUND AND OBJECTIVES: In a study of postoperative analgesia after major knee surgery, an assessment was made of the efficacy of continuous lumbar plexus block combined with a single-shot block of the sciatic nerve. METHODS: Continuous perivascular femoral and parasacral sciatic nerve blocks were performed in 59 patients of both sexes, who had undergone either total knee replacement or cruciate ligament reconstruction. An independent assessment of postoperative pain control and side effects was made. RESULTS: The combination technique produced pain control of good quality, combined with a low incidence of excessive sedation and emesis. Nausea and vomiting were infrequent, and no excess sedation, untoward side effects, or complications were noted. CONCLUSIONS: Sciatic nerve block is essential for successful analgesia during the immediate postoperative period but is not mandatory for longer-term pain control, which can be achieved by continuous lumbar plexus block.

Adolescent↗
PubMed1991

Postoperative analgesia after triple nerve block for fractured neck of femur.

Fifty patients with fractured neck of femur that required surgical correction with either a compression screw or pin and plate device were randomly allocated to receive one of two anaesthetic techniques, general anaesthesia combined with either opioid supplementation or triple nerve block (three in one block) with subcostal nerve block. The nerve blocks significantly reduced the quantity of opioid administered after operation; 48% of these patients required no additional analgesia in the first 24 hours. Plasma prilocaine levels in these patients were well below the toxic threshold, and peak absorption occurred 20 minutes after the injection. No untoward sequelae were associated with the nerve blocks.

Aged↗
PubMed2004

Mepivacaine local anaesthetic duration in equine palmar digital nerve blocks.

REASONS FOR PERFORMING STUDY: Perineural analgesics are used for lameness diagnosis but the duration of effect, knowledge of which would provide valuable information when performing subsequent blocks, is unknown. OBJECTIVE: To evaluate the duration of a palmar digital nerve block using force plate measurements. METHODS: Ten horses diagnosed with unilateral navicular syndrome were trotted at range of 3 +/- 0.15 m/sec over a force plate to record ground reaction forces for 5 trials of each forelimb. Data were recorded before nerve block, and then at 15 mins, 1, 2 and 24 h post nerve block. RESULTS: Before nerve block, peak vertical force (mean +/- s.e.) was significantly higher in the contralateral forelimb (CL = 5345 +/- 188 N) than in the lame forelimb (L = 4256 +/- 204 N; P<0.05). At 15 mins post nerve block there was no significant difference between the 2 forelimbs (CL = 5140 +/- 184 N; L = 5126 +/- 129 N), and this remained the case for 1 h. By 2 h, the mean score for the lame leg had decreased (L = 4642 +/- 182 N) but was still greater than preblock. By 24 h, vertical forces had returned to preblock values. CONCLUSIONS: The palmar digital nerve block was fully effective between 15 mins and 1 h. The analgesic effect began to subside between 1 and 2 h but sufficient analgesia persisted to affect gait characteristics beyond 2 h. POTENTIAL RELEVANCE: When using a palmar digital nerve block, it is important to perform lameness evaluations between 15 mins and 1 h to be sure of effective nerve blockade.

Anesthetics, Local↗