Comparison of general anaesthesia v/s caudal epidural in paediatric infra umbilical surgeries

Background: Our aim was to compare caudal epidural versus general anaesthesia in paediatric patients for safety, efficacy, post-operative analgesia, cost effectiveness and surgeon’s comfort. Material and Methods: 60 paediatric patients 2 -6 years of ASA grade I and II posted for infra-umbilical surgery were randomly divided in to two groups. Group C (n=30) received caudal block anaesthesia using 0.25% Ropivacaine 1ml kg -1 . Group G (n=30) received general anesthesia with Thiopentone sodium, Succinylscoline as induction agent and O2, N2O, Isoflurane and incremental doses of Atracurium as maintenance. They were extubated in a usual manner after surgery. In both groups pain was assessed by observer pain score. Observation and Results: Cost was less in group C. There was no significant change in hemodynamics in both groups. Duration of rescue analgesia was significant less in group G. Rate of post-operative complication was higher in group G. caudal anaesthesia was much accepted by surgeon. Conclusion: Caudal epidural is quite inexpensive with excellent anaesthesia and satisfactory post-operative analgesia with lesser complication rate.


1.Introduction
Caudal epidural is one of the most common regional techniques used for post-operative pain management in paediatric patients [1]. It is commonly used for procedures like urogenital, rectal, inguinal and lower extremity surgeries [2].
There are advantages to use regional anaesthesia that are evident and continue to increase the popularity of its practice. The use of regional anaesthesia in combination general anaesthesia results in reduced concentration of potent inhaled agents and reduced or absent use of opioids resulting in quick recovery time and less nausea and vomiting.
In addition, regional anaesthesia suppresses the neuroendocrine responses to surgery compared with general anaesthesia alone. Regional anaesthesia has been a therapeutic tool in treatment of post-dural puncture.
In 1954, Rouston F G in Canada and Stringer R M first described in Anaesthesia and analgesia, lumbar epidural anaesthesia for inguinal hernia repair in infants and children.
The common advantages of caudal anaesthesia are adequate anaesthesia without polypharmacy, endotracheal intubation and respiratory support, minimal biochemical and physiological differences, absence of post operative nausea and vomiting, rapid return of feeding, minimal postoperative apnoeic spells, low cost, reduction in post operative hospital admissions in an outpatients population.
Drugs, which used commonly in caudal analgesia, are bupivacaine & lignocaine. Opioids may also be used as adjunct, although they are not recommended for day case surgery because of the risk of delayed respiratory depression [3].
Ropivacaine a new long acting amide local anesthetic agent, with fewer toxic cardiac and central nervous system effects provides greater separation of sensory and motor effects. The sensory block provided by ropivacaine is similar to that produced by an equivalent dose of bupivacaine in extradural and peripheral nerve block. The motor block produced by ropivacaine is slower in onset, less intense and shorter in duration than that after an equivalent dose of bupivacaine [4].
General anaesthesia in paediatric age group may be associated with difficulty in intubation due to anatomy of larynx, delayed recovery from muscle relaxant, more incidences of post-operative nausea and vomiting which may interfere with pain perception in paediatric patient due to excessive crying.

2.Materials and Methods
This study was conducted in Dhiraj hospital in Department of Anaesthesiology after clearance from the ethical committee. All the parents of patients' participating in the study were explained clearly about the purpose and nature of the study in the language they could understand. They were included in the study only after obtaining a written informed consent. We studied 60 patients of American Society of Anesthesiologist (ASA) grade-I & grade-II, who were admitted for infra-umbilical surgery under caudal epidural anaesthesia and general anaesthesia. They were allocated randomly into two equal groups. Group C (n=30) (caudal group) received inj. Ropivacaine 0.25 % with inj. Ketamine 1-2 mg kg -1 to perform the procedure, 1ml kg -1 and group G (n=30) (general anaesthesia group) received general anaesthesia with inj. Thiopentone 5mg kg -1 & Inj. Succinylcholine 1.5 mg kg -1 as induction agent and O 2 , N 2 O, Isoflurane and incremental doses of inj. Atracurium as maintenance. They were extubated in a usual manner after surgery. The study was prospective and interventional in nature.

Inclusion Criteria
All the patients were examined preoperatively for detailed clinical and physical examination, necessary laboratory investigation were carried out. All the patients were kept nil per orally, at least for 4-6 hours prior to surgery. In the operation room after taking i.v. line, i.v. infusion with Isolyte-P was started according to body weight. All patients received premedication in the form of inj. Glycopyrrolate 0.004 mg/kg i.v.; inj. Ondansetrone 0.1 mg/kg i.v.; inj. Midazolam 0.03mg/kg and oxygenated with facemask.

a) Caudal anaesthesia technique
Group C (n=30) received Inj. Ketamine 1-1.5 mg/kg i.v. to make the patient immobile while performing caudal block with inj. Ropivacaine 0.25 % 1ml kg -1 . Patients were placed in left lateral decubitus position and the back was painted and draped. Confirmation of the bony landmarks was done. Sacral hiatus then was located. After identifying the midline, a finger was run down the tips of thoracic and lumbar spine towards the sacrum where the sacral hiatus was palpated as a depression between the two sacral cornua. Alternatively, a finger was run upwards towards the sacrum after identifying the tip of the coccyx, which then palpates the hiatus.
Once the sacral hiatus was identified, the hiatus was punctured with a short beveled 1.5 inch 23 gauge needle. The needle was inserted at an angle of 45° to the skin, until the characteristic "give" was felt, which was indicate that the sacro-coccygeal ligament was pierced. On entering the space, the needle was lowered to an angle of 20° and advanced 2-3 mm to make sure that the entire bevel was inside the space. Once the needle position was confirmed, inj. Ropivacaine 0.25% 1ml kg -1 was injected and patients were kept in supine position for 10 minutes. After 10 minutes patients were handed over to the surgeon. Throughout the surgery patients were given O 2 through venturi mask.

b) General anaesthesia technique
Patients were pre-oxygenated with 100 % oxygen for 3 minutes. Group G (n=30) received general anaesthesia with inj. Thiopentone 5mg kg -1 , Inj. Succinylcholine 1.5 mg kg -1 as induction, then were intubated with appropriate size of endotracheal tube. Patients were maintained on O 2 , N 2 O, Isoflurane, inj. Atracurium 0.5 mg kg -1 as loading dose and incremental doses of 0.1 mg kg -1 . After completion of surgery & satisfactory respiratory efforts, patient were reversed from muscle relaxants by inj. Glycopyrrolate 0.008 mg kg -1 and inj. Neostigmine 0.05 mg kg -1 i.v. slowly.
IJBR (2015) 6 (01) www.ssjournals.com Patients were monitored for Spo 2 , pulse (H.R.), Non Invasive Blood Pressure (NIBP) was recorded at 5-minute intervals for 30 minutes then at every 10 min till the end of the surgery. Patients were assessed every 30 minutes after surgery for postoperative analgesia by Observer Pain Score (OPS) [16][17] till the rescue analgesia.
Rescue medication (rectal suppository of Diclofenac 1.5 mg kg -1 ) was given when the OPS score ≥4.

Statistical analysis
Data analysis was performed using the Student's t-test. Results are presented as means SDs, numbers or percentages, and p value of < 0.05 considered statistically significant.

3.Results
Total of 60 patients were recruited for the study. There were no significant differences between the two groups in demographic data and duration of surgery ( Table 1).  Time of pre-operative preparation is considered as the time since the start of premedication till the patient was handed over to surgeon. In group C, the patients were handed over to surgeon after 10 minutes.

Figure 1: Change in heart rate and mean arterial pressure in both the groups
There was no significant change in hemodynamics in both groups. SpO 2 remained stable throughout the surgery in both the groups.     There was no incidence of any complication in group C. in group G three patients had delayed recovery and three patients had nausea and vomiting, which was significant.

4.Discussion
Epidural analgesia is now firmly established in paediatric anaesthetic practice and its popularity continues to grow. Benefits of caudal epidural include, avoidance of per operative parenteral opioids so as to limit the incidences of respiratory depression and reduction of stress hormone responses. General anaesthesia has many adverse incidences of sore throat, oral trauma, respiratory depression, delayed recovery and needfulness of multiple top-up doses of analgesics [19].
Avoidance of complications associated with endotracheal intubation as for example oral and laryngeal injury, post-operative sore throat and complication of general anaesthesia like post operative nausea and vomiting (PONV), respiratory depression, aspiration pneumonitis and awareness during anaesthesia.
Ropvacaine is a newer amide with superior post-operative analgesia and motor block by caudal administration.
Among different doses of ropivacaine, 0.25% 1 ml kg -1 showed superior postoperative analgesia [8] and significantly lower incidence of motor block [5]. In our study, Isoflurane was used as inhalation agent in Group G, Isoflurane decreases systemic vascular resistance and so reduces blood pressure and causes tachycardia. So there was a transient rise in heart rate (Miller's Anaesthesia). While the same was observed after giving inj. Ketamine before caudal block in group C.
In the present study, there was no significant difference in the two groups with regard to age and weight.
Surgeons' satisfaction was higher in group C which was comparable with the study of Himanshu et al [11]. As in group C there was better analgesia and no incidence of nausea or vomiting as compare to group G three patients had nausea and vomiting. Delayed recovery from neuromuscular blockade was sometimes considered as the prime issue especially in IJBR (2015) 6 (01) www.ssjournals.com paediatric age group where prolonged ventilation may lead to respiratory complications. In our study, group G had three patients with delayed recovery. Group C patients provided acceptable operating condition to the surgeon. In group C we had given inj. Ketamine prior to caudal block to make the patient immobile to perform the block. We had asked the surgeon to start after 10 minutes. In one patient there was delayed onset of action so we had to repeat the dose of Ketamine before starting the surgery. Time taken for pre-operative preparation was less in group G than group C.
Patients in group G, were given rescue analgesia soon after extubation. While in group C rescue analgesia was given after 4 hours of caudal block, which was significant.
In our study, post-operatively out of 30 patients all (100%) patients reached pain score 4 in less than 15 minutes in group G. In group C out of 30 patients 19 (63.3%) patients reached pain score 4 in 4 hours while 11 (36.6%) patients reached in 4.5 hours which was comparable with the study of Shah et al [11].
Cost of anaesthesia was less in group C than in group G.

5.Conclusion
Caudal anaesthesia gives better intraoperative and post-operative analgesia with fewer complications. It is also cheap and devoid of polypharmacy.