Local Anesthetic

This study is being performed to investigate whether the administration of local anaesthetic into the muscles in the abdomen or onto squirting the local anaesthetic onto the liver following keyhole gallbladder surgery is more beneficial in reducing pain post-operatively. Keyhole gallbladder surgery is typically performed under general anaesthesia (or while the patient is 'fully asleep'), however doctors use other pain relief types to reduce pain after the operation. One of these options is local anaesthetic, which involves the injection of an medication into or onto the part of the body which has been operated on. The reason for doing this is to reduce the pain felt by the patient in the part if the body where the operation occurred. The best way of using these medications remain unclear. The local anaesthetic being used in the study is fully approved for use in Ireland and the drug itself is not being tested. In other words, the drug is not an experimental drug. Local anaesthetic drugs are given in different ways in patients who have just had the keyhole surgery on their gall bladder (this is the surgery that you are about to have). Therefore, the aim of this study is to compare two ways of giving patients these local anaesthetic medications following key-hole gallbladder surgery. These include (1) injecting the medication into the skin at the surgical wounds and squirting it onto the liver (where the gallbladder has been removed from), or (2) injecting the medication into the skin at the surgical wounds and into the muscles in the abdomen (known formally as a transversus abdominus plane block).

This will be a prospective randomized study, aiming at comparing an intrathecal fixed dose of chloroprocaine 1% versus an intrathecal fixed dose of ropivacaine 0.75% in elective cesarean sections

Pediatric anesthesia presents distinctive challenges, particularly concerning appropriate dosage administration of local anesthetics for spinal anesthesia (SA). Spinal anesthesia in infants has been linked to a lower incidence of hypotension, hypoxia, bradycardia, and postoperative apnea in comparison to general anesthesia (GA); ensuring a high level of cardiovascular and respiratory stability. Additionally, SA has been linked to lower operating room time, post-anesthesia care unit, hospital length of stay, corticosteroid administration, narcotic requirements, postoperative emesis, and cardiopulmonary complications in comparison to GA. A reduction in systemic blood pressure frequently accompanies neuraxial blocks in adults, necessitating intervention. Nevertheless, spinal, caudal, or epidural blocks administered to children under six years old are not associated with any substantial alterations in blood pressure. In children aged 6 to 10, there is a linear decrease in blood pressure that will reach a plateau at approximately a 30% decrease in those beyond the age of 10. Conversely, younger children require no additional precautions. Bupivacaine, has a narrow therapeutic index in children, and its dosing requires careful consideration to strike a balance between effective anesthesia and the risk of toxicity. The traditional method of dosing bupivacaine in pediatric spinal anesthesia is based on the child's body weight. This weight-based dosing considers the assumption that children's drug clearance correlates with their body mass. However, this approach might not account for the maturational changes in drug handling by pediatric patients or the variability in spinal column length and cerebrospinal fluid volumes, not always proportional to weight but may evolve with age. Emerging evidence suggests that age-based dosing may be more effective. It hypothesizes that developmental pharmacokinetics, including changes in body composition, organ function, and drug-receptor differences, can influence bupivacaine metabolism and action more significantly than body mass alone. By accounting for the age-related anatomical and physiological changes, age-based dosing could result in more precise and effective anesthesia with a decreased risk of adverse outcomes. To the authors knowledge, there is no study comparing age-based and weight-based bupivacaine dosing for pediatric spinal anesthesia in children undergoing elective infra-umbilical surgery.

Choice of local anesthetics is the major determinant of the characteristics of a peripheral nerve block. Short acting local anesthetics while provides faster onset suffer from shorter duration. On the other hand, long acting local anesthetics while provides long duration suffered from long onset time. The ideal local anesthetics should provide faster nerve block onset while providing reasonable duration to provide sustained postoperative analgesia. Mixing short and long acting local anesthetics for nerve blocks may appear to be the solution however previous published studies have demonstrated similar onset time to long acting local anesthetics and with reduced duration. Recently, the London Health Sciences Centre established an ambulatory surgical centre. Fast onset peripheral nerve block is desirable. Previous studies have not looked at popliteal sciatic block and anecdotally we feel addition of short acting local anesthetics appear to speed up onset. We are therefore interested in conducting a randomize trial to determine whether mixing short and long acting local anesthetics can speed up onset of surgical quality block.