European Journal of Cardiovascular Medicine

Pain management in pediatric surgical patients remains a critical component of anesthetic practice. Lower abdominal surgeries such as herniotomy, orchidopexy, and circumcision cause moderate to severe postoperative pain, which if inadequately managed, can lead to physiological and psychological stress, delayed recovery, and chronic pain syndromes [1]. The administration of systemic opioids like fentanyl and morphine has traditionally formed the backbone of intraoperative analgesia in pediatric patients. However, their associated risks, particularly respiratory depression, postoperative nausea and vomiting, ileus, and sedation, have led anesthesiologists to explore alternative or adjunctive strategies [2].

Regional anesthesia techniques offer the advantage of site-specific analgesia with minimal systemic side effects. Among these, caudal epidural anesthesia has gained prominence as the most frequently employed neuraxial block in children, particularly for surgeries below the umbilicus [3]. The technique is relatively easy to perform due to the superficial location of the sacral hiatus and the predictable spread of the local anesthetic in the caudal epidural space. In children, due to incomplete ossification of the sacrum and more compliant tissues, the distribution of the drug is generally consistent and effective [4].

Caudal anesthesia has been shown to significantly reduce perioperative opioid requirements, lower the incidence of postoperative complications, and improve hemodynamic stability during surgical procedures. Ropivacaine, a long-acting amide local anesthetic, has become a preferred agent due to its favorable safety profile, lesser motor blockade, and reduced cardiotoxicity compared to bupivacaine [5]. Its sensory-selective action makes it particularly useful in pediatric practice, where preserving motor function postoperatively is beneficial [6].

Studies evaluating caudal analgesia in pediatric populations report reduced intraoperative nociceptive responses, as evidenced by more stable heart rate and blood pressure, compared to those managed solely with systemic opioids [7]. This hemodynamic stability is attributed to blockade of afferent nociceptive input, which diminishes the stress response to surgical stimulation [8]. The combination of reduced opioid requirements and better autonomic control suggests an important role for caudal blocks in enhancing anesthetic quality and safety in children [9].

Despite the apparent advantages, not all studies uniformly support the widespread application of caudal anesthesia, citing risks like inadvertent intravascular or intrathecal injection, motor block, and localized infections [10]. Nevertheless, with ultrasound guidance and careful dosing, the incidence of complications is low and largely preventable [11]. Moreover, the addition of caudal blocks to general anesthesia appears to have a synergistic benefit, lowering the intraoperative requirement for supplemental fentanyl or morphine and improving recovery profiles \12].

This prospective study aims to compare the effect of caudal anesthesia with 0.5 ml/kg ropivacaine versus general anesthesia alone in pediatric patients undergoing elective lower abdominal surgeries. Specifically, the study investigates intraoperative opioid (fentanyl) consumption and perioperative hemodynamic changes. The hypothesis is that caudal anesthesia significantly reduces opioid usage and stabilizes hemodynamics during surgery, thus enhancing anesthetic safety and recovery in the pediatric population.

Study Design and Setting

This prospective, comparative study was conducted in the Department of Anesthesiology and Pediatric Surgery at a tertiary care teaching hospital over a period of 18 months. The study was approved by the Institutional Ethics Committee, and written informed consent was obtained from the parents or legal guardians of all participants.

Study Population

Sixty pediatric patients, aged between 1 and 10 years, scheduled to undergo elective lower abdominal surgeries such as herniotomy, orchidopexy, and circumcision under general anesthesia were enrolled in the study. Patients were classified as American Society of Anesthesiologists (ASA) physical status I or II.

Inclusion Criteria

* Age between 1 and 10 years

* Elective lower abdominal surgery under general anesthesia

* ASA grade I or II

* Informed consent from parents/guardians

Exclusion Criteria

* Coagulopathy or bleeding diathesis

* Infection at the sacral site

* Known allergy to local anesthetics

* Pre-existing neurological or spinal disorders

* Emergency surgeries

* Children on chronic opioid therapy

Randomization and Group Allocation

Patients were randomly allocated into two equal groups (30 each) using a computer-generated random number table:

* Group 1 (Caudal Group): Received caudal anesthesia with 0.5 ml/kg of 0.2% ropivacaine in addition to general anesthesia

* Group 2 (Control Group): Received general anesthesia alone without any regional block

Anesthesia Protocol

All children were kept nil per oral as per ASA guidelines. On arrival in the operating room, standard monitors (pulse oximetry, electrocardiography, non-invasive blood pressure) were attached. An intravenous line was secured, and premedication with midazolam 0.05 mg/kg IV was given.

All patients received fentanyl 2 mcg/kg intravenously at induction. Anesthesia was induced with propofol (2–3 mg/kg) and maintained with a mixture of oxygen, air, and sevoflurane. Atracurium was used for muscle relaxation, and a suitable-sized endotracheal tube was inserted.

In Group 1, after induction and before surgical incision, the patient was placed in the lateral decubitus position with hips and knees flexed. Under aseptic precautions, caudal block was administered using a 22G short bevel needle via the sacral hiatus. After confirming the absence of blood or cerebrospinal fluid on aspiration, 0.2% ropivacaine was administered at a dose of 0.5 ml/kg.

Both groups were monitored continuously for intraoperative heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), and oxygen saturation. Hemodynamic readings were recorded at 5-minute intervals throughout the procedure.

Intraoperative Fentanyl Supplementation

Additional fentanyl (0.5–1 mcg/kg) was administered intraoperatively in either group if a ≥20% rise from baseline in heart rate or blood pressure was noted, indicating pain or inadequate depth of anesthesia.

Outcome Measures

The primary outcome measure was total intraoperative fentanyl consumption in micrograms per kilogram. The secondary outcomes included intraoperative hemodynamic changes (heart rate and mean arterial pressure) and any complications associated with the caudal block.

Postoperative Monitoring

After surgery, patients were extubated and shifted to the post-anesthesia care unit (PACU), where they were monitored for two hours for respiratory rate, oxygen saturation, sedation, and pain using the FLACC (Face, Legs, Activity, Cry, Consolability) score. However, only intraoperative data were included in the final analysis for this study.

Statistical Analysis

All data were entered into Microsoft Excel and analyzed using SPSS version 25.0. Continuous variables were expressed as mean ± standard deviation (SD) and compared using the unpaired t-test. Categorical variables were expressed as numbers and percentages and analyzed using the chi-square test. A p-value of <0.05 was considered statistically significant.

A total of 60 pediatric patients were enrolled in the study and randomized equally into two groups of 30 each. The demographic profiles between the two groups were statistically comparable, as shown in [Table 1].

The mean age In Group 1 was 4.5 ± 2.1 years, and in Group 2 it was 4.7 ± 2.3 years (p=0.65). The mean weight in both groups was also similar, and gender distribution did not differ significantly.

Table 1: Demographic profile of the study population

Intraoperative fentanyl requirements were significantly lower in the caudal group. The average dose required in Group 1 was 0.8 ± 0.3 mcg/kg compared to 2.2 ± 0.4 mcg/kg in Group 2. This difference was statistically significant with a p-value of <0.001 [Table 2].

Table 2: Intraoperative fentanyl consumption (mcg/kg)

Heart rate measurements taken at different surgical time points indicated significantly better hemodynamic stability in the caudal group. While baseline heart rates were comparable, Group 2 showed significant increases after incision and during surgery [Table 3].

Table 3: Heart rate (beats per minute) during surgery

Mean arterial pressure also followed a similar trend. Group 1 maintained relatively stable MAP values, while Group 2 experienced noticeable elevations following incision and during the operative course [Table 4].

Table 4: Mean arterial pressure (mmHg) during surgery

Bar graph: Intraoperative Fentanyl Consumption (mcg/kg)

Bar graph: Hemodynamic Comparison – Heart Rate and MAP at Different Time Points

Effective perioperative pain management is vital in pediatric anesthesia not only for patient comfort but also to minimize the physiological stress response to surgery. The current study demonstrated that caudal anesthesia with ropivacaine 0.5 ml/kg significantly reduced intraoperative fentanyl consumption and provided greater hemodynamic stability in pediatric patients undergoing lower abdominal surgeries.

The findings align with previous studies showing that caudal blocks can markedly reduce systemic opioid requirements during surgical procedures. In our study, fentanyl requirements in the caudal group were approximately 65% lower than in the non-caudal group, a statistically and clinically significant difference. This is consistent with the work by Hong et al., who observed reduced fentanyl usage in children undergoing hypospadias repair when caudal blocks were used [13].

Ropivacaine, used in our study due to its reduced cardiotoxicity and sensory-motor separation properties, has shown excellent safety and efficacy in pediatric neuraxial blocks. In a randomized comparison, Ivani et al. reported that ropivacaine produced reliable analgesia with fewer motor blockade events compared to bupivacaine in children undergoing infraumbilical surgeries [14].

The attenuation of intraoperative hemodynamic fluctuations in the caudal group in our study is another important finding. Increased heart rate and mean arterial pressure are often indicative of insufficient analgesia or surgical stress, leading to the need for additional opioids or deepening of anesthesia. Our study supports the evidence presented by Ahmed et al., where caudal blocks were associated with significantly more stable intraoperative cardiovascular parameters [15].

Further, the physiological basis for this effect is rooted in the blockade of afferent nociceptive input via the caudal epidural space, thereby limiting the sympathoadrenal stress response. Wolf et al. emphasized the role of regional anesthesia in blunting perioperative stress markers like cortisol and catecholamines, which may also contribute to better perioperative homeostasis [16].

Concerns regarding the safety of caudal blocks have historically included risks of dural puncture, local anesthetic toxicity, and infection. However, with appropriate technique, aseptic precautions, and correct dosing, these complications remain rare. Our study reported no such adverse events, which is in agreement with the findings of Giaufré et al., who documented a low incidence of complications in a multi-center survey on pediatric regional anesthesia [17].

Moreover, our results underscore the growing emphasis on opioid-sparing strategies in pediatric anesthesia. Opioids, while effective, are associated with delayed recovery, nausea, vomiting, and respiratory depression—particularly concerning in children with limited respiratory reserves. Thus, regional blocks like caudal anesthesia, when properly administered, serve a dual purpose of reducing opioid burden and enhancing intraoperative stability [18].

A potential limitation of our study is the non-inclusion of postoperative analgesia duration and pain scores. Several studies have shown that caudal anesthesia not only reduces intraoperative fentanyl requirement but also provides effective postoperative analgesia for up to 4–6 hours [19]. However, our study was specifically designed to focus on intraoperative opioid consumption and hemodynamic trends.

Finally, while the study was randomized and prospective in nature, the sample size was moderate. Future multi-center studies with larger populations and inclusion of postoperative variables could further strengthen the understanding of caudal block utility in pediatric anesthesia.

This prospective study provides strong evidence supporting the use of caudal anesthesia with ropivacaine as a beneficial adjunct to general anesthesia in pediatric patients undergoing lower abdominal surgeries. The administration of a single-dose caudal block with 0.5 ml/kg of 0.2% ropivacaine significantly reduced intraoperative opioid (fentanyl) requirements and provided superior hemodynamic stability compared to general anesthesia alone.

Children in the caudal group exhibited lower heart rates and mean arterial pressures throughout surgery, suggesting improved intraoperative analgesia and reduced surgical stress response. Importantly, the use of caudal anesthesia was not associated with any complications in our study population, further confirming its safety when performed under proper aseptic technique and dosing guidelines.

Reducing intraoperative opioid use is a key objective in pediatric anesthetic practice due to the potential adverse effects of systemic opioids. The opioid-sparing effect of caudal blocks enhances the quality of anesthesia while contributing to faster recovery and fewer side effects.

In conclusion, the addition of caudal epidural anesthesia using ropivacaine is a safe and effective technique to minimize intraoperative opioid consumption and maintain hemodynamic stability in pediatric patients undergoing infraumbilical surgeries. Its routine use should be encouraged, especially in centers equipped with trained personnel and appropriate monitoring facilities. Future studies including postoperative analgesia duration and pain scores would provide a more comprehensive understanding of its benefits in the perioperative setting.

Conflict of interest: Nil

Funding: Nil

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