European Journal of Cardiovascular Medicine

In anesthesiology practice, brachial plexus block is a proven technique for upper extremity surgery [1]. Common upper extremity surgeries in children include supracondylar fractures, forearm fractures, implant removal, and cross-digit flap surgery. Brachial plexus sensory block for intraoperative analgesia provides hemodynamic stability during surgery, smooth emergence from general anesthesia, and reduced need for additional analgesics or suppositories postoperatively [2]. The most commonly used agents for this purpose are local anesthetics. However, it is often desirable to extend the duration of action of local anesthetics, which would prolong the anesthesia and analgesia during surgery. Commonly used local anesthetic adjuvants include clonidine, opioids such as fentanyl and morphine, sodium bicarbonate, vasoconstrictors, and dexamethasone. Dexamethasone helps by attenuating the release of inflammatory mediators, reducing ectopic neuronal discharge, and inhibiting the discharge of pain sensory C-fibers via potassium channels [3]. The addition of steroids to local anesthetics effectively and significantly prolongs the analgesic effect and has a faster onset of action in adults [4,5].

Ultrasound guidance allows real-time visualization of anatomical structures and confirmation of the spread of the injected anesthetic solution. Since most local anesthetic procedures are performed under general anesthesia, this is an attractive option for pediatric patients [6]. The safety and efficacy of local anesthetic procedures in children is supported by an extensive literature. It has been demonstrated that combined local and general anesthesia can shorten hospital stay and improve outcomes in pediatric patients [7]. Although there is some controversy regarding the performance of local anesthesia in sedated children, there is consensus among pediatric anesthesiologists on the importance and feasibility of safely using local anesthetic techniques under general anesthesia [8]. Against this background, the following study was conducted to evaluate the efficacy of dexamethasone as an adjuvant to bupivacaine in brachial plexus block under ultrasound guidance and general anesthesia.A

This was a prospective, double-blind, randomized controlled trial conducted at a tertiary care teaching hospital in central India over a 12-month period from October 2023 to September 2024. The study was conducted in 60 pediatric patients scheduled for forearm and hand surgery with the approval of the institution's human ethics committee and written informed consent from the parents. The study was conducted in patients aged 4-12 years with American Society of Anesthesiologists (ASA) physical status classifications 1 and 2 scheduled for forearm and hand surgery under general anesthesia.

The primary outcome was measured as duration of analgesia, which was defined as the time from block to when the child reported moderate pain. Secondary outcomes included postoperative pulse rate, blood pressure, nausea, and vomiting.

Exclusion criteria were parents' refusal to allow their child to participate in the study, patients with coagulopathy, infection at the site of occlusion, peripheral neuropathy, neuropathy, and known allergies to local anesthetics.

The preanesthetic examination included a detailed examination of the airway, respiratory system, and cardiovascular system. Basic clinical laboratory data were reviewed, and all patients were abstained from oral fluids for 8 hours before surgery.

Patients were randomly divided into two groups of 15 patients each: group B (0.125% bupivacaine 0.5 ml/kg) and group BD (0.125% bupivacaine 0.5 ml/kg + dexamethasone 0.1 mg/kg). Randomization was performed using the envelope method.

Two anesthesiologists participated in the study.

Aesthesiologist 1: performed the randomization, assigned patients to the study groups, and filled the drugs for the brachial nerve block.

Aesthesiologist 2: performed the block and monitored the Wong-Baker Scale (FACES) in the postoperative ward, as the drug injected in the patient was unknown [9].

The patient was transferred to the operating room and connected to monitors including noninvasive blood pressure measurement (NIBP), pulse oximetry, electrocardiogram (ECG), and chest stethoscope. An intravenous (IV) cannula was secured, and 500 ml of Ringer's lactate was injected. All patients received standard general anesthesia. The patient was preoxygenated and given 1 µg/kg fentanyl intravenously. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and after adequate mask ventilation, vecuronium 0.08 mg/kg was administered. The airway was secured with a cuffed endotracheal tube. Relaxation was maintained with vecuronium 0.02 mg/kg every 20 minutes. Anesthesia was maintained with nitrous oxide 66%, oxygen 33%, and isoflurane 0.4%. Heart rate, blood pressure, electrocardiogram, and oxygen saturation were monitored and recorded at 5-minute intervals during the procedur

Brachial plexus block was performed via a supraclavicular approach under ultrasound guidance. Before starting the surgery, general anesthesia was administered and a blockade was performed. The children were lying supine with their heads away from the sides of the obstruction. The target area was prepared with betadine solution, and a hockey stick-type ultrasound linear probe (5–10 MHz) with a 22G 50 mm needle was used, which was covered with a sterile wrap and gel. The probe was placed on the coronal slope of the supraclavicular fossa, and puncture was performed in the lateral to medial aspect. The dose of bupivacaine [10] used was 0.5 ml/kg in both groups, and the dose of dexamethasone [11] in the BD group was 0.1 mg/kg.

At the end of the surgery, neostigmine 0.05 mg/kg and atropine 0.02 mg/kg were administered intravenously to release muscle relaxation, and the tracheal tube was removed. Upon arrival in the recovery room, blood pressure, heart rate, and oxygen saturation were monitored. Monitoring of vital parameters such as pulse rate and blood pressure continued for three hours after surgery, after which the pediatric patients were discharged from the PACU. Postoperative pain monitoring was performed at different intervals according to the Wong-Baker scale. The time to first emergency analgesia was recorded and, if required, 15 mg/kg intravenous paracetamol was administered. Hemodynamic variables and the incidence of postoperative nausea and vomiting were compared between the two groups.

Statistical Analysis

The data obtained from the study were analyzed using Statistical Package for Social Sciences (SSPS) version 10 computer software. Data are expressed as frequencies, percentages, means, and standard deviations (SD). Student t test was used to compare means between two groups. Nonparametric Mann-Whitney U test was used to compare different groups. For all statistical analyses, a two-tailed p value of less than 0.05 was considered significant.

[Table 1] shows the gender distribution between the groups was unequal, with Group BD having fewer females which was found to be statistically significant p<0.05. There was no statistical significance between the groups with respect to the age and weight.

Table 1: Demographic details of the study participants.

Data presented as mean±SD.

The pulse rate and blood pressure in both groups pre-operatively and post-operatively showed no significant changes as shown in [Tables 2 and 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 2: Pulse rates of the study participants.

Data presented as mean±SD.

Table 3: Blood pressure measurements in both the groups.

a)

Data presented as mean±SD.

b)

Data presented as mean±SD.

[Table 4] shows the duration of surgery was comparable between the groups with Group B lasting for 40.66±11.05 minutes and Group BD, 36.33±10.15 minutes

Table 4: Duration of surgery.

Data presented as mean±SD.

[Table 5] shows the duration of analgesia in group B was 12.93±10.373 hours and in group BD was 26.13±12.421 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 5: Time to rescue analgesia.

Data presented as mean±SD.

[Table 6] shows no significant difference in the incidence of Post-Operative Nausea and Vomiting (PONV) in both groups.

Table 6: Incidence of PONV

χ2 = 0.239 p=0.623.

Regional blocks are becoming more and more popular in pediatric surgery. Regional or nerve blocks with general anesthesia are known to reduce the need for general anesthesia, reduce the stress response, reduce pain when the patient awakens, and avoid side effects that may occur with intravenous administration of opioid narcotics. They are also said to be superior in postoperative pain relief [12]. In pediatrics, supraclavicular brachial plexus blocks with long-acting local anesthetics have been used and have been shown to provide better postoperative analgesia than intravenous bolus or continuous infusion or rectal administration [13].

The results of this study can be compared with the study by Choi S et al. In adults, data from nine studies (801 patients) who received local anesthetics (LA) alone or in combination with local anesthetics and perineural dexamethasone (4-10 mg) were included [14]. Their conclusion was that dexamethasone extends the duration of analgesic action of long-acting LA from 730 to 1306 minutes (mean difference 576 minutes). The results of this study were also consistent with a study by Desmet M et al., in which perineural dexamethasone was used for interscalene blockade during adult shoulder surgery. The results showed a sensory blockade of 1405 minutes [15].

Vieira PA et al. also found that dexamethasone prolonged the median sensory blockade (1457 vs. 833 min, p < 0.0001) and motor blockade (1374 vs. 827 min, p < 0.0001) compared to the control group and concluded that the addition of dexamethasone to local anesthetics prolongs the duration of analgesia [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 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]. The study also measured the frequency of postoperative nausea and vomiting and postoperative hemodynamics. Three patients (20%) in group B and two patients (13.3%) in group BD complained of PONV, although no statistical significance was shown (p=0.624). This may be attributed to the effects of general anesthesia in these patients. Mean systolic and diastolic blood pressures measured 20, 60, 120, and 180 minutes after surgery did not show statistical significance. There are very limited data on this in pediatric patients undergoing regional blockade under general anesthesia.

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.

Limitation

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.

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