Local Anesthetics
Sahab Uddin, Rashid Mamunur in Advances in Neuropharmacology, 2020
Myotoxicity, first described more than 55 years ago by Brun (Brun, 1959), after peri- and retrobulbar block during ophthalmologic procedures relates to a great occurrence of muscle dysfunction. Even though all clinically used LAs may cause skeletal muscle injury, even leading to muscle necrosis, tetracaine, and procaine are less disposed to myotoxicity. By contrast, bupivacaine seems to be the LA with higher toxicity. Nevertheless, the myonecrosis of skeletal muscle is an unusual side effect that in most cases is reversible (Dippenaar, 2007). The severity of the damage is dose-dependent. Furthermore, it worsens when the LA is administered by continuous infusion or when serial injections are done. After injection, there is hypercontraction of the myofibrils that over the next 1–2 days is followed by lytic degeneration of the sarcoplasmic reticulum (SR), myocyte edema, and necrosis. In most cases, the muscle fibers regenerate within 3–4 weeks. Nonetheless, the concomitant administration of epinephrine and corticosteroids potentiates the severity of myotoxicity, even leading to permanent muscle damage.
Procedural and Perioperative Pain Management for Children
Mark V. Boswell, B. Eliot Cole in Weiner's Pain Management, 2005
Successful block of virtually any peripheral nerve or plexus may be accomplished with appropriate equipment and sufficient practitioner interest (Dalens, 2000; Ross et al., 2000; Sethna & Berde, 1994). Supraorbital and occipital nerve blocks provide analgesia over the anterior and posterior scalp, respectively, and may be used for laceration repair or to provide analgesia following craniotomy. Infraorbital nerve block and various palatal blocks provide analgesia of the upper lip and palate for procedures including cleft lip and cleft palate repair, and may be particularly useful in medically disadvantaged settings when avoidance of opioid is desired. Retrobulbar block anesthetizes orbital contents and induces profound analgesia of the globe and surrounding structures; ophthalmologists generally perform such blocks. Intercostal nerve blocks provide excellent analgesia and enhance pulmonary function following thoracotomy (Matsota, Livanios, & Marinopoulou, 2001), and lessen pain of thoracostomy tubes and rib fractures. Periumbilical compartment block is useful for umbilical hernia repair, while ilioinguinal and iliohypogastric nerve blocks are useful for a variety of unilateral inguinal and groin procedures. Numerous techniques for penile nerve block in distal penile surgery including circumcision and hypospadias repair have been described. Although preemptive peripheral nerve blocks offer theoretical advantages of preemptive analgesia and lessened overall pain experience, this has not been reliably demonstrated in clinical practice, particularly in children (Ates, Unal, Cuhruk, & Erkan, 1998; Suresh et al., 2004).
Common Vitreoretinal Procedures
Pradeep Venkatesh in Handbook of Vitreoretinal Surgery, 2023
In early postsurgery IOL dislocation, it is highly probable for the cataract wound to have been left sutureless or with a solitary suture. When this is encountered, it is safe to first secure the wound by passing additional sutures under topical anaesthesia and only then administer peribulbar or retrobulbar block. Application of super-pinkie or digital massage is absolutely contraindicated. In patients in whom no corneal wound is visible, one must look for the presence of a scleral wound under the conjunctiva. This is a likelihood when the demographics and circumstances indicate the possible surgery as being manual small incision cataract surgery rather than phacoemulsification.
Efficacy of Intravitreal Dexamethasone Implant in Patients of Uveitis Undergoing Cataract Surgery
Published in Ocular Immunology and Inflammation, 2019
Gaurav Gupta, Jagat Ram, Vishali Gupta, Ramandeep Singh, Reema Bansal, Parul Chawla Gupta, Amod Gupta
Patients were admitted one day prior to surgery (if needed) or surgery was done on day care basis or on outpatient basis. Same experienced surgeon (JR) performed all the surgeries, strictly adhering to principles of closed chamber technique in both the groups. Written informed consent was taken from every patient before the surgery. All surgeries were performed under local anesthesia using peribulbar or retrobulbar block. After adequate anesthesia, intravitreal 700 µg dexamethasone implant was given 3.5 mm away from the limbus inferotemporally in DEXA implant group patients only. Two side port incisions were created at 9 and 2 o’clock position using 15° disposable knife and main port was made using 2.2 mm disposable keratome. The anterior chamber was formed using high viscosity viscoelastic (1.4% sodium hyaluronate). Small pupils were managed using Iris hooks or Malyugin’s ring. A 5–5.5 mm continuous circular capsulorrhexis was made using Uttrata’s forceps. In cases of white cataract, trypan blue dye (0.06%) was used to stain anterior capsule. Cortical cleavage hydrodissection was performed with nuclear rotation. Lens nuclear emulsification was done by phacoemulsification. The cortical matter was removed by bimanual irrigation-aspiration (I/A). Foldable hydrophobic acrylic IOL was implanted in the capsular bag in all cases. A subconjuctival injection of gentamycin (20 mg) and dexamethasone (4 mg) was given at the end of surgery.
Diplopia after Cataract Extraction
Published in Seminars in Ophthalmology, 2018
Marc A. Bouffard, Dean M. Cestari
It may be difficult to tell whether there is an advantage in the choice of retrobulbar or peribulbar block as a means to mitigate the chance of postoperative diplopia. Capo, Roth, and Johnson found no difference in the frequency of postoperative diplopia between patients anesthetized with retrobulbar versus peribulbar blocks among 19 patients.14 Conversely, seven of the nine patients in Esswein and von Noorden’s smaller series of patients with postoperative diplopia received peribulbar blocks.15 Given the longer needle length and trajectory required to administer a retrobulbar block, one might assume a resultant increase in the probability of injuring either the cranial nerves or the extraocular muscles. It might also be assumed that the shorter needle and extraconal target of a peribulbar block might confer less risk of direct trauma or anesthetic-related myotoxicity. However, peribulbar blocks typically require a larger volume of anesthetic than is used in retrobulbar blocks to achieve adequate analgesia, thus anesthetic myotoxicity may be just as potent. It is important to note that injury to cranial nerves or extraocular muscles is possible, even under circumstances of correct technical performance.
Fentanyl as an adjuvant to the local anesthetic in the peribulbar block for vitrectomy operations
Published in Egyptian Journal of Anaesthesia, 2023
Abeer A Hassanin, Hossam Elden M Moharam, Shimaa H Hassan, Sahar A Hashish
Retrobulbar block (RBB) is superior to PBB in terms of delivering adequate anesthesia, akinesia, and postoperative analgesia, but it has a greater risk of serious complications, including retrobulbar hemorrhage and globe perforation. PBB has the disadvantage of a slow start of orbital akinesia and the recurring need for block replenishing, but it causes less discomfort, has less toxicity, and lowers the likelihood of optic nerve sheath penetration (Alhassan et al., 2007) [2].
Related Knowledge Centers
- Abducens Nerve
- Eye
- Hypokinesia
- Local Anesthesia
- Nerve Block
- Oculomotor Nerve
- Optic Nerve
- Trochlear Nerve
- Cranial Nerves
- Extraocular Muscles