Dose Comparison of Hyperbaric Bupivacaine for Spinal Anaesthesia in Children Undergoing Infra-Umbilical Surgeries

INTRODUCTION: Spinal anaesthesia is induced by injecting small amounts of local anaesthetic into the cerebro-spinal fluid (CSF). The injection is usually made in the lumbar spine below the level at which the spinal cord ends. Spinal anaesthesia is easy to perform and has the potential to provide excellent operating conditions for surgery below the umbilicus. Advantages include rapid onset, profound sensory and motor block, and lack of systemic effects, avoidance of tracheal intubation and a decreased need for opioid administration. Other theoretical benefits include the attenuation of the neuroendocrine response to surgical stress, facilitation of rapid tracheal extubation (for combined techniques), improved ventilatory mechanics, and decreased post-anaesthesia care unit and hospital stay. Spinal anaesthesia is an excellent option in paediatric population as it provides a rapid onset of profound and predictable uniformly distributed analgesia with good neuromuscular blockade. Spinal anaesthesia has traditionally been used in ex-premature neonates and infants<60 weeks post-conceptional age who are at an increased risk of post-operative apnoea due to bronchopulmonary dysplasia and prematurity. Spinal anaesthesia has also been used in older children to provide intra- and post-operative analgesia, especially for procedures done as day-case surgery. Paediatric spinal anaesthesia has proven to be a safe alternative to routinely administered general anaesthesia as it avoids the polypharmacy associated with the latter technique and also reduces the incidence of post-operative respiratory complications associated with administration of general anaesthesia. AIM OF THE STUDY: To compare two different doses- 0.3mg/kg and 0.5mg/kg- of 0.5% hyperbaric Bupivacaine given intrathecally in children aged 5-12 years undergoing surgeries of the lower extremities and infra-umbilical procedures; in terms of duration of analgesia and incidence of intra- and post-operative complications. CRITERIA FOR PATIENT SELECTION: Children of either sex aged between 5 and 12 years belonging to ASA Physical Status I/II. Exclusion Criteria include: • Parental refusal • Children with congenital malformations altering the surface Anatomy, • Known coagulopathy, • Infection at the site of injection, • Generalised sepsis, • Children with known epileptic disorders or uncontrolled seizures, • Children known to have raised intracranial tension, • Children with a ventriculo-peritoneal shunt. Relative contraindication would be a child with an uncontrolled respiratory tract infection or an anticipated difficult airway. The intended procedure was explained to the parents, all queries clarified and their due consent obtained. MATERIALS: Materials required for the study include: • Spinal tray- comprising of o 5cm 25g Quincke-Babcock, o 9cm 25g Quincke-Babcock needles for older children, o Sterile 2 ml syringe, o Sterile gauze, o Sponge-holding forceps, o Sterile drape, o Disinfectant solution. • Hyperbaric Bupivacaine 0.5% ampoules, • Midazolam for oral pre-medication, • Topical local anaesthetic cream Prilox, • Drugs for general anaesthesia in case of inadequate block, • Intravenous cannulae and I.V.fluids, • Emergency drugs, • Monitors- Pulse oximeter, Electrocardiogram, Non-invasive Blood Pressure. STUDY METHODS: The study was conducted as a Randomised controlled study with blinding of the patients. From the results obtained in the Pilot study, a target population of 30 subjects in each of the two groups- control and test was decided. After proper screening for the above-mentioned criteria, the parents were informed about the purpose of the study and the procedure and intended study methods the day before surgery. Parents were required to give their written consent on the morning of surgery. Selected children were randomly assigned to two groups- labelled as B1 and B2. Randomisation was achieved by allotting lot numbers; odd numbers were assigned to group B1 and even numbers to group B2. All children were fasted pre-operatively - 6hours for solids and 2hours for clear fluids. Oral pre-medication of Midazolam at a dose of 0.5mg/kg37 mixed with 5-10ml non-particulate apple juice was administered to all children one hour before the procedure. At the time of pre-medication, topical local anaesthetic cream (Prilox- Eutectic mixture of Local Anaesthetics: Lignocaine and Prilocaine) was applied to the site of intended lumbar puncture and potential sites of venepuncture and an occlusive dressing applied. STATISTICAL ANALYSIS: A sample size of 30 per group was decided during the pilot study. Randomisation of subjects to the two groups was done by allotting random numbers to each. Children with odd numbers were allotted to Group B1 and those with even numbers were allotted to Group B2. Data was expressed as mean + SD. Quantitative analysis was compared with student’s t-test: Equal-Variance T-Test Section for comparison of discrete variables and the Aspin-Welch Unequal-Variance Test for continuous variables. When using the student’s t-test to compare the mean among the two groups, p-value of less than 0.05 was taken as significant. The patients in each group were comparable in distribution in terms of age, weight and sex distribution. SUMMARY: In our Randomised controlled, single-blind trial involving 30 subjects in two groups; we compared the safety and efficacy of using ahigher dose of hyperbaric bupivacaine in children aged between 5-12 years. Our observations include the following: • Spinal anaesthesia is a safe technique for providing surgical anaesthesia in children. • Spinal anaesthesia can be used as a stand-alone technique with minimal premedication in paediatric surgery, especially for day-case procedures. • Pre-loading was not required to prevent any fall in blood Pressure. • Haemodynamic stability is the rule in children younger than 12 years. • In children weighing over 15 kg, 0.5mg/kg can be used safely to provide a more predictable level of blockade and a longer duration of surgical anaesthesia and post-operative analgesia. CONCLUSION: Spinal anaesthesia was demonstrated to be a safe anaesthetic technique for paediatric surgery. The rapid onset and predictable motor blockade, with minimal requirement of supplemental anaesthesia prove to be advantageous in day-case surgeries in children. A higher dose of Hyperbaric 0.5% Bupivacaine at 0.5mg/kg body weight is found to be safe in children belonging to the 5-12 year age group and can be dependably used as the sole anaesthetic technique. There is no increased risk of complications. At the same time, the higher dose provides a more predictable height of sensory blockade and a longer duration of both surgical anaesthesia and post-operative analgesia in comparison to the conventional dose of 0.3mg/kg

Metabolic profile in right lobe living donor hepatectomy: Comparison of lactated Ringer′s solution and normal saline versus acetate based balanced salt solution - a pilot study

Background and Aims: Lactate levels predict outcomes after hepatectomy. We compared metabolic effects of lactated versus lactate free solutions in living donor hepatectomy. Methods: Consecutive right lobe donors (n = 53) were alternatively allotted to lactated Ringer′s solution and normal saline (Group L-control) or acetated crystalloid (Sterofundin B Braun ® Group S -study group) in an observational prospective randomised study. The primary outcome measure was lactate level, and secondary outcomes were base excess, bicarbonate, glucose and chloride intra- and post-operatively. Mann-Whitney and Chi-square tests were used for analysis. Results: The intraoperative, post-operative lactate levels and the time for normalisation were comparable. Group L had significantly lower intraoperative bicarbonate levels (mmol/L) at 6 and 8 h (20.0 ± 2.14 vs. 21.3 ± 1.6, P = 0.0471; 18.68 ± 2.04 vs. 20.39 ± 17, P = 0.002), base excess at 4 and 6 h (mmol/L) (−3.64 ± 2.73 vs. −3.0 ± 1.52, P = 0.031; −6.64 ± 2.76 vs. −4.35 ± 1.7 P = 0.006). The intraoperative chloride levels (mmol/L) were higher in group L at 4 and 8 h (108 ± 5.9 vs. 105.99 ± 2.76, P = 0.0471; 109.51 ± 3.86 vs. 106.93 ± 3.09, P = 0.002). Intraoperative glucose (mg/dL) at 6 h was higher in group L, 160.55 ± 31.52 vs. 145.5 ± 24.29, P = 0.043. The highest post-operative chloride (mmol/L) was higher in Group L (112.3 ± 3.86 vs. 109.81 ± 3.72, P = 0.034). Post-operative base excess and bicarbonate showed an improved profile in Group S (−7.37 ± 2.99 vs. −5.06 ± 1.71 P = 0.001 and 17.79 ± 2.23 vs. 19.68 ± 1.51 P = 0.005). Conclusion: Acetated fluids were associated with higher levels of bicarbonate, lesser base deficit, glucose and chloride but no difference in lactate levels in comparison with Ringer′s lactate and normal saline in living donor hepatectomy