Spinal anaesthesia in children under sedation

Spinal anaesthesia in children evolved more than hundred years ago and gaining considerable popularity worldwide. In our setups in Bangladesh, this technique has not gained popularity yet but over the past few years this technique has been practiced in some centers. The objective of the present study was to observe the efficacy and safety of spinal anaesthesia under sedation in children scheduled for infra-umbilical surgical procedures. In this study, 67 children of age ranging from 2 to 10 years of either sex, with American Society of Anaesthesioloists physical status I and II, undergoing infra-umbilical surgeries were included. Spinal anaesthesia was administered with Quincke 27 gauge needles between L4–L5 or L5-S1 interspace in the lateral position under sedation with ketamine and midazolam. Heart rate, mean arterial blood pressure and oxygen saturation (SpO2) were monitored throughout perioperative period. Complications of sedation and spinal anaesthesia were recorded and managed accordingly. Among 67 children, male and female were 62 (92.5%) and 5(7.5%), respectively. The mean (SD) age, body weight, American Society of Anaesthesiologists physical status I and II was 5.2 (2.1) years, 15.5 (4.8) kg, 60 (89.6%) and 7 (10.5%), respectively. Successful spinal anaesthesia was done in all cases. The incidences of side effects of sedation were transient apnoea 1 (1.5%), desaturation (SpO2<93%) 3 (4.5%), stridor 1 (1.5%), laryngospasm 1 (1.5%) and agitation 4 (6.0%). Side effects were transient, self limiting and managed conservatively. Complications of spinal anaesthesia were hypotension 2 (3.0%), bradycardia 1 (1.5%), shivering 1 (1.5%), nausea and vomiting 1 (1.5%) and backache 1 (1.5%). The complications were minor and managed accordingly. There were no serious adverse events reported in any child. The mean (SD) operation time and recovery time from anaesthesia was 49.2 (8.4) minutes and 91.2 (9.2) minutes, respectively. Spinal anaesthesia under sedation with ketamine and midazolam is safe and effective technique for paediatric infraumbilical surgery.


Introduction
The first report on pediatric spinal anesthesia was reported by Bier in 1899, when the technique was performed with cocaine in an 11 year old boy for ischial abscess drainage. 1In 1900, Bainbridge reported a case of an infant of three months for the repair of a strangulated hernia using spinal anesthesia. 2 In 1909, a detailed procedure of pediatric spinal anesthesia was published by Tyrell-Gray reporting experience from 300 pediatric surgical procedures. 3By middle of the century, considerable improvement in techniques of general anaesthesia (introduc-can Society of Anaesthesiologists (ASA) physical status I and II, patients scheduled for elective surgery below umbilicus, parents gave consent for spinal anesthesia, and expected duration of surgery around 60 to 90 minutes.
Exclusion criteria were: parental refusal, coagulation abnormalities, local infection at the spinal puncture site, neurological abnormalities such as spina bifida, increased intracranial pressure, uncorrected hypovolemia, and allergy or hypersensitivity to local anesthetic drugs.
All children were fasted 6 hours for solid food, 4 hours for liquid food and 2 hours for clear fluids before operation.An intravenous line was established with 20 or 22 gauge cannula in the operation theatre.A loading dose of injection ketamine 1 mg/kg body weight was given intravenously over 60 seconds.Injection midazolam 0.1 mg/kg body weight was given intravenously to prevent agitation and nightmares.The maintenance of spontaneous respiration was verified and oxygen was supplemented via facemask.Baseline vital parameter; pulse oximetry (SpO 2 ), heart rate, ECG, mean arterial blood pressure (MAP) were recorded.Patients were positioned in lateral position without flexing neck, taking care of airway.The lumbo-sacral region was scrubbed with antiseptic solution of povidone iodine solution and then draped with sterile towels.Lumber puncture was performed with 27 gauge Quincke spinal needle at L4-L5 or L5-S1 interspace.After free reflux of cerebrospinal fluid (CSF) 0.5% bupivacaine (hyperbaric) 0.3 mg/kg body weight was injected slowly over 30 seconds into the subarachnoid space.The spinal needle was then slowly withdrawn.Punctured area was covered with sterile gauze and then patient was put in the supine position.The efficacy of the sensory block was assessed with response to pin prick and motor block in the flaccid paralysis of lower extremities (unable to move hip, knees and foot).
After establishment of the block the required surgery was allowed to perform.The patient's tion of muscle relaxants and safe intravenous induction agents) was achieved; however, lack of expertise for spinal anaesthesia (fear of adverse effects, lack of parent and patient cooperation) possibly prevented widespread use of spinal anaesthesia in children.In the last decade, it started being advocated by many centers due to increasing knowledge on pharmacology, safety information and availability of specialized equipment for regional anaesthetic techniques and monitoring in children.
Children usually cannot tolerate the administration of spinal anaesthesia unless they are deeply sedated or on general anesthesia.Most children require additional sedation (ketamine, midazolam, thiopentone, propofol, halothane, sevoflurane, nitrous oxide, etc) for performing spinal anaesthesia and surgical procedure. 4,5][8][9][10][11][12] Ketamine produces a unique state of cortical dissociation that allows painful procedures to be done more consistently and effectively than with other procedural sedation and analgesia drugs.This state of dissociative sedation is characterized by profound analgesia, sedation, amnesia, and immobilization, and can be rapidly and reliably produced with intravenous or intramuscular administration. 13,14 therefore designed a case series study to analyze the feasibility of spinal anaesthesia for infraumbilical surgery in children under procedural sedation with ketamine and midazolam.

Materials and method
This prospective case series analysis was done in Prime Medical College and Hospital, Rangpur within the period of 12 months from January 2015 to December 2015.Study was approved by the Research Ethics Committee of the Institution.The study was conducted on total 67 patients.
Inclusion criteria were: age-2 years to 10 years, gender-both male and female, Ameri-provided there were no surgical restrictions.Patients were followed postoperatively in the ward to evaluate late complication of spinal anaesthesia like postdural puncture headache (PDPH), transient neurological symptoms, meningitis, meningism, backache and urinaryretention.Results were reported using descriptive statistics (Microsoft Excel; Microsoft Corporation) and expressed as mean (SD) or percentage (%) where appropriate.

Results
Patient's characteristics are presented in Table 1.Among 67 children, male and female were 62 (92.5%) and 5(7.5%), respectively.The mean (SD) age, body weight, ASA physical status I and II was 5.2 (2.1) years, 15.5 (4.8) kg, 60 (89.6%) and 7 (10.5%),respectively.Different types of surgical procedures are presented in Table 2. Types of surgery were inguinal hernia repair 28 (41.8%),circumcision 17 (25.4%),appendicectomy 8 (11.9%), rectal polypectomy 6 (9.0%), hypospadius repair 5 (7.4%) and orchidopexy 3 (4.5%).Haemodynamic parameters of the children were shown in Table 3. Haemodynamic parameters of the patients were almost stable in all cases.The incidences of side effects of sedation were shown in Table 4.The incidences of side effects of sedation were: transient apnoea 1 (1.5%), desaturation (SpO 2 <93%) 3 (4.5%),stridor 1 (1.5%), laryngospasm 1 (1.5%) and agitation 4 (6.0%).Side effects were transient, self limiting and managed conservatively.Complications of spinal anaesthesia were shown in Table 5.The complications of spinal anaesthesia were hypotension 2 (3.0%), bradycardia 1 (1.5%), shivering 1 (1.5%), nausea and vomiting 1 (1.5%) and backache 1 (1.5%).The complications were minor and managed accordingly.There were no serious adverse events reported in any child.The duration of operation time and recovery time is shown in After completion of surgery, patients were transferred to recovery room and their vital signs were monitored, till the block regressed.Recovery status was assessed by Aldrete Recovery Score (ARS). 16atients were considered ready to be discharged from recovery room when they had stable vital signs, oriented, had no intractable nausea or vomiting, had minimum pain, and ARS is persistently at least 8 or more than 8. Recovery time was calculated as the time from the last dose of medication given until discharge criteria were met.The children were then transferred to ward, where fluid maintenance continued until oral food allowed, children were allowed to feed as soon as possible,

Discussion
There are important anatomic differences between children and adults, which are related to the child's development stage which should be considered at performing spinal anesthesia in children.Neonates spinal cord extends at the level of the third lumbar vertebra and, at the end of the first year of life reaches the location seen in adults, at the first lumbar vertebra. 17,180][21] In this study spinal block was performed either L4-L5 or L5-S1 interspace.
Cardiovascular changes related to the spinal anaesthesia are less common in children than in adults.In children under 5 years of age, minimal changes in heart rate and blood pressure have been reported. 22,23In older patients (>8 years old), the sympathetic block can induce bradycardia or hypotension.In this study patients were haemodynamically stable in almost cases.Hemodynamic suppression following spinal anaesthesia is absent in children due to a smaller peripheral blood pool, immature sympathetic autonomic system, and compensatory reduction in vagal efferent activity. 24ence, preloading before spinal anaesthesia is not a routine in children. 25rforming spinal puncture in a struggling, agitated child may injure delicate neurovascular structures and should be avoided.Most children require additional sedation (ketamine, midazolam, thiopentone, propofol, halothane, sevoflurane or nitrous oxide). 26,27n this study, sedation regimen with ketamine and midazolam provided optimal conditions for spinal anaesthesia represented success rate 100%.General anaesthesia regarded to be safe, but the risk of post operative apnoea and hypoxaemia is not negligible in infants who are born preterm and operated upon before post conceptual age of 46 weeks. 28,29he rate of apnoea in this study was very low, short apnoea after induction of sedation required short time bag-valve-mask ventilation until spontaneous respiration regained.The specific dangers of airway compromise are suggested to be less with ketamine. 30,31ncidences of desaturation (SpO 2 <93%) found in 4.5% children, managed with managed with supplemental oxygen, 3% children, who suffered from laryngospasm and stridor, could be treated conservatively.The fewer incidences of airway problems and desaturation supported the safety of ketamine administration regarding airway and hypoxia. 9,12,32Though midazolam was given, few incidences of agitation were observed in this study and those were transient and minor inconvenience.
We assessed efficacy of the sensory block with response to pin prick and motor block by flaccid paralysis in the lower extremities.In awaken children the extent of the sensory block can be checked by pin prick or skin pinch and that of the motor block by Bromage scale. 33This may, however, be difficult to check in a deeply sedated child, inability to move the blocked extremity after emergence is a good evidence of successful block.
The complications related to spinal anaesthesia are usually either due to the needle used to perform the procedure (backache, headache, nerve or vascular injury, infection, etc) or the drugs injected (high or total spinal, drug toxicity).Complications in children are lower than in adults. 34However, problems associated with regional anaesthesia in children may be underestimated. 35arly complications of spinal anaesthesia like hypotension 3%, bradycardia 1.5%, desaturation 1.5%, shivering 1.5% and nausea and vomiting in 1.5% were observed in this study.Those were mild and treated accordingly with minimum interventions.In this study, we found late complications of spinal anaesthesia like backache 1.5%, no incidences of PDPH and transient neurological symptoms.PDPH is rare in paediatric patients and some authors have even challenged its existence. 36Backache is a common complaint, found in 5-10% patients but its causal relationship has not been established. 37Transient neurological symptoms reported 3-4% and described as new onset of pain and peraesthesia originating in gluteal region and radiating to lower limbs. 37n most cases, symptoms are mild.A one year study of 24409 regional blocks in children by the French-Language Society of Pediatric Anesthesiologists, the largest known study on complications, revealed a complication rate of 1.5 per 1000 in the 60% of children receiving central neuraxial blocks. 38Association des Anesthésistes Réanimateurs Pédiatriques d'Expression Française's prospective study in preterm to adolescent patients reported only one complication (intravenous injection) after 506 spinal anaesthesia. 34e mean (SD) recovery time from anaesthesia was 91.2 (9.2) minutes.Spinal anaesthesia under sedation with ketamine is safe and effective technique for paediatric infraumbilical surgery but it delays recovery when used with short acting benzodiazepines like midazolam.
A limitation of this study was that we could not measure end tidal carbon dioxide (EtCO 2 ).For measurement of EtCO 2 , special sensor containing facemask is required.

Conclusion
Spinal anaesthesia under ketamine sedation is safe technique in children in the hands of an experienced anesthetist with proper patient selection, drugs, and dosages.Spinal anaesthesia might be an effective choice in children undergoing elective surgeries below umbilicus, rather than just as an alternative to general anaesthesia.