Effect of Spinal Anaesthesia in Children of 4 -10 Years

Background : Though paediatric spinal anaesthesia has been used since early 20th century in developed countries even in neonates, still it is not common in our country. Spinal anaesthesia can be given in neonates and children for infraumbilical surgeries with an expert and experienced anaesthesiologist. Objective : The objective of this study was to establish spinal anaesthesia as a safe and effective regional anaesthetic procedure in children of 4–10 years. Materials and Methods : The study was done in the Department of Anaesthesiology & Intensive Care Unit of Enam Medical College & Hospital during the period of June 2012 to May 2014. A total of 102 patients aged from 4 to 10 years with American Society of Anaesthesiologists (ASA)-I and II were selected. After proper preoperative anaesthetic evaluation spinal anaesthesia was administered. All patients were premedicated with atropine, preloaded with crystalloid solution and sedated with ketamine 1 mg/kg or midazolam 0.03 mg/kg. 0.5% hyperberic bupivacaine was injected at L4/5 or L5/S1 level with spinocaine needle. After establishment of desired block, surgery was performed. All vital parameters, number of attempts for lumbar puncture, sensory and motor block were monitored and recorded. Results : Almost all patients achieved desired block (T8–T10) within 5 to 10 minutes. The success rate in our study was 96.1% and remaining 3.9% were considered as failure. No remarkable changes were observed in vital parameters after spinal anaesthesia. Lumbar puncture was successful in first attempt in 60 (58.82%) cases and in second attempt in 42 (41.18%) cases. Hypotension occurred in 2%, shivering in 3% and 3% developed restlessness. Conclusion : Spinal anaesthesia produces a reliable, profound and uniformly distributed block with rapid onset, good muscle relaxation, complete control of cardiovascular and stress responses compared with epidural or GA. There is also rapid recovery and minimal complications without special drugs or expensive equipments. However, greater acceptance and experience are still desired for this technique to become more popular. J Enam Med Col 2017; 7(1): 10-14

[9][10] However, paediatric spinal a n aesthesia never achieved its popularity because of continuous discoveries of newer and better volatile agents and muscle relaxants for general anaesthesia.In the last decade, many centres begun to advocate spinal anaesthesia in children due to increasing knowledge on pharmacology, safety information and of specialised equipments for regional a n aesthetic techniques and monitoring in children.In future, paediatric spinal anaesthesia will not only be used in cases where general a n aesthesia is r isky or contraindicated but also be the preferred choice in most lower abdominal and lower extremity surgeries in children. 11Technological advances and better training of intensive care unit staffs have increased the survival r a te.Spinal a n aesthesia has been proposed as the single anaesthetic technique with the a im of decreasing immediate postoperative apnoea.Though spinal a n aesthesia is gaining popularity in children, the misconceptions regarding its overall safety, feasibility and reliability can only be better known with more use and research. 11Very few studies are available highlighting the experience of spinal anaesthesia in children regarding its safety, success rate and complications.So we designed this study to prospectively analyse the success rate, complications and haemodynamic stability related to spinal anaesthesia in paediatric patients of 4-10 years over a period of two years.

Materials and Methods
This study was conducted in the Department of Anaesthesiology and ICU, Enam Medical College & Hospital, Savar, Dhaka for 2 years duration (1 st June, 2012 to 30 th May, 2014).Total 102 subjects were included in the study.Informed written consent was obtained from parents of each patient for participation in the study and the various a spects of regional technique along with the risks involved were explained in details.There is also an obvious need to assess the risk involved in the procedure on an individual case basis versus the benefits expected depending on the nature and duration of surgery, general condition of the patient and the a vailability of institutional care intra-a n d postoperatively.All paediatric patients of 4-10 years of age who were given spinal anaesthesia were included in the study.All patients under study were subjected to detailed pre-anaesthetic evaluation.The standard preoperative fasting guidelines were followed before elective spinal anaesthesia.There a r e important a n atomic differences between children and adults, which are related to the child's development stage that should be considered at spinal blockade.The important factor is CSF volume which in the adult is 140 mL with 75 mL in the spinal space.In children, total volume varies from 40 to 60 mL with half of it in the spinal space. 12So, although a reduced total volume in children, the relative volume is higher (2 mL/kg in adults and 4 mL/kg in children).Children's spinal cord is highly vascularised a llowing a fast local a n aesthetic clearance. 13ter establishment of intravenous a ccess, a ll were preloaded with crystalloid solution (baby saline) 10 mL/kg within a period of 30-40 minutes.Heart r a te, blood pressure, and oxygen saturation were measured and noted as baseline values.Injection atropine 0.01 mg/kg was given as premedication.All children except those who were cooperative and calm were sedated on the operating table before subarachnoid block u sing ketamine 1 mg/kg, fentanyl 1-2 mcg/kg, or midazolam 0.03 mg/kg IV to provide an immobile patient for lumbar puncture.All patients received spinal anaesthesia via midline approach under aseptic precautions with patients in lateral position.Lumbar puncture was performed in L4-L5 intervertebral space using standard 25G or 27G quincke spinal needles (9 cm).After getting free flow of CSF, hyperbaric bupivacaine heavy (0.5%) was injected in the subarachnoid space (in a dose of 0.5 mg/kg for children <5 kg, 0.4 mg/kg for children 5-15 kg, 0.3 mg/kg for children >15 kg 14 ).Sensory level was assessed by lack of response to firm skin pinch to the dermatomal level and also using modified Bromage score 15 .Desired peak sensory level was aimed to be T10 for assessing the success rate of spinal anaesthesia.Sensory block characteristics, motor block characteristics and complications related to anaesthesia such as vomiting, shivering, postdural puncture headache a n d a n y manifestation suggestive of neurological injury were also 11 recorded.The patients were monitored u n til full recovery.

Discussion
This study was undertaken to evaluate the efficacy and safety of spinal anaesthesia in the paediatric population.General anaesthesia may be associated with several lifethreatening complications, especially with comorbidities like difficulty in intubation, failed intubation, hypoxia, delayed r everse, incomplete reverse, other reversal hazards such as hypothermia, post-operative apnoea, post-operative hypoxia, sore throat, tongue fall back, shivering, cyanosis a n d perioperative cardiac arrest. 16In the healthy children, most of the procedures like herniotomy, circumcision, minor urological a n d orthopaedic procedures a r e performed as day-case surgeries.Spinal anaesthesia is a very good alternative for such cases where the child can be returned to the family and a lot of stress to the parents is avoided. 11This method of anaesthesia may avoid the increased incidence of postoperative respiratory complications a ssociated with general anaesthesia.Spinal anaesthesia has been found to be more cost-effective as compared to general anaesthesia.The drugs and equipments required are less and cheaper and length of hospital stay is usually shorter.
The major advantage of spinal anaesthesia in children is the cardiovascular stability. 17Differently from adults, children have little or no heart rate and blood pressure changes.Factors involved in this extraordinary haemodynamic stability are still not totally defined.One theory is that the r elative immaturity of the Herniotomy Appendicectomy sympathetic nervous system would make children's vasomotor tone less dependent on this system and that capacitance veins in lower extremities are small and send little blood flow for this region. 18Respiratory failure or apnoea may occur when sensory and motor block levels are above the first thoracic dermatome (T 1 ), and may need for ventilatory assistance until blockade regression.It is speculated that the drug uptake is faster in the subarachnoid space owing to proportionally greater blood flow to the spinal cord as compared with adults. 19With faster drug distribution and elimination, childrens' motor level regression is approximately 5 times faster than in adults.This causes a decreased duration of block.For this reason, spinal anaesthesia alone is generally restricted to one hour duration surgeries only.
In 1984, Blaise et al 20 conducted a study on paediatric spinal anaesthesia in 34 patients aged from 7 weeks to 13 years with ASA-I physical status.In their study, four patients required GA due to failure of lumbar puncture by two attempts.There was no episode of hypotension.In our study four patients needed GA due to failure to achieve desired block after 10 minutes and two patients developed hypotension.
In 1998, Kokki et al 21  Overall patient safety, feasibility and reliability are the key features of this technique which will only become better with greater use, experience and research. 11mong the various drugs approved by Food and Drug Administration for paediatric use, 0.5% bupivacaine heavy is common and popular.
Spinal anaesthesia produces a reliable, profound and uniformly distributed sensory block with rapid onset and good muscle relaxation.It results in more complete control of cardiovascular and stress responses than epidural or opioid anaesthesia.The failure rate of spinal anaesthesia was low in our study.Owing to high success rate (96.1%) and very low complication rates, our study breaks the misconception regarding the feasibility and safety of paediatric spinal anaesthesia.
From our study we can recommend that spinal anaesthesia is ideal, safe and cost-effective for day-case surgeries and there is no additional requirement of any special drugs or equipments for the procedure.Because of these benefits, spinal anaesthesia can be preferred for children undergoing surgery in the lower part of the body.However, further studies with larger sample size are recommended.

Table I :
Distribution of study subjects according to types of surgeries (n=102) mean pulse rate showed no significant change from baseline afterwards.Only 2 (2%) patients had a single episode of hypotension after 10 minutes of SAB, which was successfully managed.Fig 1 shows the vital parameters at different time periods.Fig 1. Vital parameters at different time periods After 10 minutes of SAB 98 (96.1%) patients achieved desired peak sensory level of T10 and Bromage score of 3. Surgery was completed in all these cases without anaesthetic supplementation.The success rate of SAB was 96.1%,only 4 (3.9%)cases required GA.
patients and second attempt was required in 29 (43.9%)patients.In our study, LP was successful in first attempt in 60 (58.82%) patients and 42 (41.18%)required second a ttempt.Mean arterial blood pressure was normal in 100 (98.03%) patients a n d heart r a te increased in 11.3% patients.