This was a prospective double blind randomized controlled trial conducted in Father Muller Medical College and Hospital over a period of 8 months from October 2014 to June 2015. The study was carried out on 30 paediatric inpatients scheduled for forearm and hand surgery after obtaining Institutional Human Ethics Committee approval and written informed parental consent. The study was performed on American Society of Anaesthesiologists (ASA) physical status 1 and 2 patients with an age range of 4-12 years scheduled for forearm and hand surgery, under general anaesthesia.

The primary outcome was measured as duration of analgesia which was defined as time from when block was given, to the time where child complained of moderate pain. Secondary outcomes measured were Post-operative pulse rate, blood pressure, nausea and vomiting.

Exclusion criteria involved were parental refusal to include their child into the study, patient with coagulopathy, infection at the site of block, peripheral neuropathy, neurological disorders and any known allergy to local anaesthetics.

During pre-anaesthetic checkup detailed assessment of airway, respiratory and cardiovascular system was carried out. Basic laboratory data was reviewed and all patients were kept nil per oral for 8 hours prior to the surgery. Patients were randomly divided into 2 groups of 15 each, Group B (0.125% bupivacaine 0.5ml/kg) and Group BD (0.125% bupivacaine 0.5ml/kg + 0.1mg/kg of dexamethasone). Randomization was done by the sealed envelope technique.

Two anaesthesiologists were involved in the study.

Anaesthesiologist 1: Randomized, allocated the patients to the study groups and loaded the drugs for the brachial block.

Anaesthesiologist 2: Blinded to the drug injected to the patients, performed the block and monitored the Wong Baker (FACES) scale in the Post-operative ward [9].

The patients were shifted to the operation theatre and the following monitors were connected–Noninvasive Blood Pressure (NIBP), pulse oximetry, electrocardiography (ECG), precordial stethoscope. Intravenous (IV) cannula was secured and 500 mL of Ringer Lactate was started. All patients received standard general anaesthesia. The patients were preoxygenated and fentanyl 1mcg/kg I.V. was given. Anaesthesia was induced with thiopentone sodium 5mg/kg intravenously followed by 0.08mg/kg of vecuronium after confirming adequate mask ventilation. Airway was secured with cuffed endotracheal tube. Relaxation was maintained with vecuronium in doses of 0.02mg/kg every 20 minutes. Anaesthesia was maintained with nitrous oxide 66% and oxygen 33% and isoflurane 0.4%. Intraoperative monitoring of heart rate, blood pressure, electrocardiogram, and oxygen saturation was undertaken and recorded at 5 minute intervals.

The Brachial plexus block was administered by the supraclavicular approach under ultrasound guidance. The block was performed after administering general anaesthesia, prior to the start of operative procedure. The children were in supine position with their heads facing away from the side of the block. The region was prepped with betadine solution and the hockey stick linear probe of the ultrasound (5-10MHz) with sterilized plastic wrap and gels, and 22G 50mm needle was used. The probe was placed in the coronal - oblique plane in the supraclavicular fossa and the puncture was in plane from lateral to medial. The dose of bupivacaine [10] used was 0.5ml/kg in both groups and that of dexamethasone [11] used in Group BD was 0.1mg/kg.

At the end of the surgery, the neuromuscular blockade was reversed using neostigmine 0.05mg/kg and atropine 0.02mg/kg intravenously and the trachea was extubated. On arrival in the Post-operative ward baseline blood pressure, heart rate and oxygen saturation was monitored. Monitoring of vital parameters such as pulse rate and blood pressure was continued for 3 hours Post-operatively after which the paediatric patient was shifted out of the Post Anaesthesia Care Unit (PACU). Post-operative pain monitoring was done at varied intervals by Wong Baker scale. The time to first rescue analgesic was noted and injection paracetamol 15mg/kg intravenous was given at the time of demand. The haemodynamic variables and incidence of Post-operative nausea and vomiting was compared between the two groups.

Data obtained from the study was analysed using the computer software Statistical Package for Social Sciences (SSPS) version 10. Data are expressed in Frequency, Percentage, Mean and Standard Deviation (SD). Student’s t-test was used to compare the mean value between two groups. To compare different groups with each other, non-parametric Mann Whitney’s U-test was employed. For all statistical evaluations, a two tailed probability p-value of < 0.05 was considered significant.

n=15

n=2(Z_α+ Z_β)² σ ²/d² where Z_α = 1.96 with 95% confidence interval

Z_β = 0.84 at 80% power

σ = √σ₁² + σ₂²/ 2 (σ₁= SD in group 1, σ₂= SD in group 2

d = X₁– X₂ (mean in group 1 = X₁, group 2 = X₂)

[Table/Fig-1] shows the gender distribution between the groups was unequal, with Group BD having fewer females which was found to be statistically significant p=0.014. There was no statistical significance between the groups with respect to the age and weight.

The pulse rate and blood pressure in both groups pre-operatively and post-operatively showed no significant changes as shown in [Table/Fig-2,3] as both groups received adequate analgesia following surgery. They were followed up for haemodynamics only until 180 minutes after which they were shifted out of PACU.

[Table/Fig-4] shows the duration of surgery was comparable between the groups with Group B lasting for 41.66±12.05 minutes and Group BD, 37.33±11.15 minutes.

[Table/Fig-5] shows the duration of analgesia in group B was 13.93±11.373 hours and in group BD was 27.13±13.421 hours and was highly significant. (p=0.008). This duration was considered as time to when the patient complained of moderate pain (Wong Baker score of 4 or more). [Table/Fig-6] shows no significant difference in the incidence of Post-Operative Nausea and Vomiting (PONV) in both groups.

Regional blocks are becoming more popular in paediatric surgery. It is known that regional or nerve blocks with general anaesthesia allows for decreased requirement of general anaesthesia drugs, decreased stress response, patients having less pain on awakening and avoidance of the potential side effects that may occur with intravenous use of opioid narcotics. It is also said to provide excellent post-operative pain relief [12]. Supraclavicular brachial plexus blocks with long acting local anaesthetics have been used in paediatrics and are known to provide superior analgesia in the post-operative period, as compared to intravenous bolus or continuous infusions and per rectal routes of administration of analgesic drugs [13].

This study results are comparable to the study done by Choi S et al., in adults where data from nine trials (801 patients) were included with patients receiving either Local Anaesthetic (LA) alone or local anaesthetic with perineural dexamethasone (4-10mg) [14]. Their conclusion was that dexamethasone prolonged the analgesic duration for long acting LA from 730min to 1306min (mean difference 576min). The present study done in paediatric age group showed that addition of dexamethasone showed a statistically significant increase in the duration of post-operative analgesia 27±13.42 hours in group BD as compared to group B where duration of analgesia was 13.93±11.373 hours. This study results were also in agreement to the study conducted by Desmet M et al., where perineural dexamethasone was used in interscalene block for shoulder surgery in adults with their results showing sensory block of 1405 minutes [15]. Vieira PA et al., in his study also found that dexamethasone prolonged median sensory (1457 vs. 833 min, p<0.0001) and motor (1374 vs. 827min, p<0.0001) blockade compared with the control thereby concluding that dexamethasone prolongs the duration of analgesia when added to a local anaesthetic [13]. The present study did not examine the effects of dexamethasone on analgesic quality because of the subjective nature of the outcome and the age group involved in the study. Nonetheless, studies have shown that local anaesthesia with perineural dexamethasone resulted in patients reporting qualitatively ‘better’ analgesia or lower pain scores than without the use of steroid [13,14,16]. None of the patients in the study groups showed signs of neuronal damage. To date, there are no reports of dexamethasone-induced neuronal damage. To the contrary, in vitro murine studies have actually demonstrated that dexamethasone attenuates the neurotoxicity of bupivacaine at a cellular level [17]. This study also measured incidence of post-operative nausea and vomiting and haemodynamics post-operatively. It showed no statistical significance (p=0.624) although 3 patients in group B (20%) and 2 patients in group BD (13.3%) did complain of PONV. This can be attributed to the effects of general anaesthesia in these patients. The mean systolic and diastolic blood pressure measured at 20 minutes, 60 minutes, 120 minutes and 180 minutes post-operatively showed no statistical significance. There is very limited data on the same in paediatric patients undergoing regional blocks under general anaesthesia. A comparative study done by Kumar S. et al., on ropivacaine and ropivacaine with dexamethasone in supraclavicular brachial plexus block for post-operative analgesia reported no toxicity profile and it was well tolerated with no incidence of post-operative nausea, vomiting, paresthesias or arrhythmias [18].

A study done by Gehdoo RP et al., on post-operative pain management in paediatric patients suggests that it is now widely accepted that the paediatric population require adequate pain relief in the post-operative period for a smoother and rapid outcome [12]. Hence simple nerve block techniques can be used safely to relieve post-operative pain. Newer modalities of pain management should be considered wherever possible.

The present study did not examine the effects of dexamethasone on analgesic quality because of the subjective nature of the outcome and the age group involved in the study. The sample size of the study population was fairly small. Since, it was paediatric age group, follow-up of haemodynamic parameters following discharge from PACU was difficult.

The addition of dexamethasone to bupivacaine significantly prolongs the duration of analgesia in children undergoing upper limb surgeries under supraclavicular brachial plexus block and general anaesthesia with no significant effects on haemodynamics or post-operative nausea and vomiting.