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At least 19 recordsLinked to original sources

Post-operative analgesia following femoral-neck surgery--a comparison between 3 in 1 femoral nerve block and lateral cutaneous nerve block.

A prospective controlled randomized trial on patients receiving surgery for fractured neck of femur was carried out, in which post-operative analgesic requirements in three separate groups were compared. Patients in Group 1 acted as controls, whilst those in Groups 2 and 3 received lateral cutaneous nerve blocks and 3 in 1 femoral nerve blocks, respectively. Patients in Group 3 needed significantly less analgesia than the other two groups, and the time to first administration of analgesia was significantly longer. No complications of either of the nerve blocks was noted.

Aged

Inadvertent abducens nerve block during therapeutic trigeminal nerve block. A case report.

A case is presented where reversible abducens nerve block accompanied second and third division trigeminal block with bupivacaine on two occasions. Intraorbital injection through the inferior orbital fissure most likely took place. Careful poistioning of the needle and limitation of the drug volume is mandatory for therapeutic trigeminal nerve blocks with neurolytic solutions.

Aged

Sciatic nerve block for children. Sciatic nerve block by the anterior approach for postoperative pain relief.

This study aimed to establish whether it was practical to perform sciatic nerve block by the anterior approach in a group of children of different ages and weights. A total of 82 blocks were performed of which 78 (95.2%) were judged to have been successful. The technique of the block differed slightly from that used in adult practice, in that great reliance was placed on the loss of resistance felt as the needle point passed through the thigh muscles into the sciatic neurovascular compartment. There were no immediate or late complications associated with this block in any of the patients. It is concluded that the block is easy to perform and can produce reliable postoperative analgesia for most common operations on the foot and ankle in paediatric practice.

Acetaminophen

Popliteal sciatic nerve block aided by a nerve stimulator: a reliable technique for foot and ankle surgery.

The reliability of popliteal sciatic nerve blocks was prospectively assessed in 625 blocks performed in 507 patients. The sciatic nerve was approached at the apex of the popliteal fossa, in the midline, with an insulated needle connected to a peripheral nerve stimulator partially designed by one of the authors. When needed, an inguinal paravascular femoral nerve block was also performed. The drugs used were 1% mepivacaine or 0.5% bupivacaine with or without 1:200,000 epinephrine. The sciatic and femoral nerves were blocked with 30 ml and 10 ml of local anesthetic, respectively. The block was sufficient to provide surgical anesthesia in 92%; supplemental analgesia was necessary in 5% and general anesthesia was required in 3% of the cases. Discomfort associated with the block procedure was found to be minimal by 89% of the patients, moderate by 9% and severe by 2%. Overall satisfaction with perioperative analgesia was evaluated by 466 patients: 444 (95%) were completely satisfied, 20 (4%) expressed moderate reservations and two (1%) expressed major reservations. The authors conclude that the technique is a safe and reliable alternative to more common forms of anesthesia for surgery below the knee. They attribute the great success rate to a high popliteal approach, the use of insulated needles, a discriminating mode of nerve stimulation and the systematic search for optimal response to needle stimulation.

Adolescent

Molecular mechanisms of nerve block by local anesthetics.

Local anesthetics block nerve conduction by preventing the increase in membrane permeability to sodium ions that normally leads to a nerve impulse. Among anesthetics containing tertiary amine groups, the cationic, protonated form appears to be more active than the neutral form. However, the neutral forms, as well as uncharged molecules like benzocaine and the aliphatic alcohols, also depress sodium permeability. Studies of single myelinated nerves and squid axons show no direct interaction between calcium ions and local anesthetics, thus disproving theories based on competition between these two agents. Likewise, hypotheses attributing local anesthesia to changes in electrical potentials at the membrane-water interface are disproven by the demonstrated potencies of electrically uncharged anesthetics. Hypotheses that propose that local anesthetics act by expanding the nerve membrane and causing a change in protein conformation that blocks sodium permeability are vague in conception and difficult to test experimentally. Evidence from voltage-clamp studies of single nerve fibers indicates that anesthetic molecules interact with the sodium channels directly, from the inner side of the nerve membrane. Anesthetics bind within sodium channels which have opened during membrane depolarization, preventing the normal sodium ion flux. Anesthetic molecules can dissociate from open channels, but not from channels that remain closed when the nerve is kept at rest. The "gating" properties that regulate the opening and closing of sodium channels are reversibly modified during anesthesia. Specifically, the inactivation function responds more slowly and requires more negative membrane potential changes to reach the same values as in unanesthetized nerves. A second, slow inactivation is observed following external application of tertiary amine anesthetics. The selective binding of anesthetics to open sodium channels provides a simple explanation for Wedenski inhibition, in which the block increases with the frequency of nerve impulses. When impulses occur at higher frequencies more sodium channels are open over a period of time comparable to the time necessary for the anesthetic binding reaction, thus more channels are blocked. In addition the changes of the inactivation function result in a longer refractory period and, thus, a decrease of impulse height at higher frequencies. Charged anesthetic molecules may bind in the pore of the sodium channel. Their binding can be modulated by the electrical field in the membrane. The channel has a higher affinity for larger anesthetic molecules, but this may result from their greater hydrophobicity as well as from their size. The binding site favors molecules that contain more polar linkages between the amine group and the aromatic residue. Binding of amine anesthetics is weakly stereospecific and, surprisingly, shows no absolute requirement for the terminal alkyl ammonium moiety present in most local anesthetics...

Action Potentials

Axillary nerve blocks.

Axillary nerve block is a safe and reliable method of providing anesthesia for the upper extremity. It is particularly useful because it can be applied in cases of traumatic injury where general anesthesia might present particular hazards. The use of a large volume of anesthetic solution is important, particularly when it is essential to block the musculocutaneous or axillary nerve.

Adult

[New aspects of field blocks and peripheral nerve blocks (author's transl)].

There have been no new developments concerning field blocks. The need for limiting the dosage of local anesthetic agents is stressed. Two methods for perivascular block are described and the use of CO2 containing local anesthetic solutions is discussed as well as the employment of peripheral nerve stimulators.

Bupivacaine

Duration of action of nerve blocks produced by mixtures of local anesthetics and low molecular weight dextran: studies in rat infraorbital nerve blocks.

The duration of rat infraorbital nerve block by 1% lidocaine or 0.25% bupivacaine, and its modification by low molecular weight dextran, was investigated in a randomized, observer-blind study. The addition of low molecular weight dextran did not prolong the duration of the blocks. No evidence of slow releasing or local anesthetic binding properties attributed to low molecular weight dextran was found.

Anesthetics, Local

[Efficacy and safety of thoracic paravertebral block combined with thoracic nerve block for acute herpes zoster neuralgia involving upper thoracic dermatomes in middle-aged and elderly patients].

To investigate the clinical efficacy and safety of ultrasound-guided thoracic paravertebral block (TPVB) combined with pectoral nerve block (Pecs) in the treatment of acute herpetic neuralgia (AHN) involving the upper thoracic segments in middle-aged and elderly patients, a prospective study was conducted. A total of 70 middle-aged and elderly patients with upper thoracic AHN who visited the Department of Pain Medicine at Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, from June to December 2023, were enrolled and randomly divided into a control group and an experimental group using a random number table, with 35 patients in each group. The control group received TPVB once weekly for a total of 3 sessions, while the experimental group received TPVB combined with Pecs block using the same regimen. Outcome measures included the Visual Analogue Scale (VAS) for pain, Pittsburgh Sleep Quality Index (PSQI), 7-item Generalized Anxiety Disorder Scale (GAD-7), 9-item Patient Health Questionnaire (PHQ-9), treatment satisfaction score, incidence of postherpetic neuralgia (PHN), rescue analgesia, and adverse events. Assessments were conducted at 1, 4, 8, and 12 weeks post-treatment, and between-group differences were compared. Ultimately, 33 patients in the experimental group and 31 in the control group completed the follow-up and were included in the final analysis. The results showed that both groups demonstrated significant improvements in VAS scores, PSQI, GAD-7, PHQ-9, and satisfaction scores compared with baseline (all P<0.05). Compared with the control group, the experimental group exhibited significantly lower VAS scores and higher satisfaction scores at 1, 4, and 8 weeks post-treatment (P<0.05), as well as significantly lower PSQI, GAD-7, and PHQ-9 scores at 4 and 8 weeks (P<0.05). There were no statistically significant differences between the two groups in the incidence of PHN, rescue analgesia, or adverse events (all P>0.05). This study demonstrates that compared with TPVB alone, the combination of TPVB and Pecs block provides better pain relief, improves sleep quality, and alleviates anxiety and depression in middle-aged and elderly patients with upper thoracic AHN, with a favorable safety profile.

Humans