Evaluating Caudal Block Enhancements in Pediatric Circumcision: Do Additional Analgesics Make a Difference?

Background

Circumcision involves exposing the tip of the penis by surgically cutting away the foreskin, called the prepuce, which covers the glans [1]. The most widely performed operation in the world is circumcision, which is also the oldest surgery in the world when you consider its progression over time [2]. Pain during surgical procedures in children causes many physiological, local, and/or systemic adverse effects [3]. These effects may lead to delays in recovery, increased consumption of narcotic analgesics and associated complications, prolongation of hospital stays, and chronic pain [4].

Opioids used for postoperative analgesia in children have adverse effects such as superficial respiration and decreased intestinal motility, nausea, vomiting, pruritus, and addictive behavior [5]. Because it has been used for so long in children, caudal block is regarded as the best multimodal analgesic for patients in this age range [6]. Caudal block is an effective method for postoperative analgesia in anorectal surgery, intraluminal surgery, and perineal surgery (eg, circumcision). Caudal block also reduces the use of analgesics without causing a motor block, which allows rapid mobilization of patients and reduces the incidence of postoperative adverse effects [7]. As it provides visceral analgesia, a caudal block is still the preferred method of analgesia in the pediatric age group [8–10].

The primary aim of this study was to compare the effects of caudal block alone vs with the addition of paracetamol or meperidine to caudal block on postoperative analgesia in patients undergoing circumcision surgery.

Material and Methods

ETHICS APPROVAL AND INFORMED CONSENT:

Ethics approval for the research was obtained from the Ordu University Clinical Research Ethics Committee (Decision No. 2022/223, Date: 04.11.2022) to ensure strict compliance with the principles delineated in the Declaration of Helsinki. Consent was obtained from the families of the children who would undergo circumcision surgery.

STUDY DESIGN AND SETTING:

This study was designed as a prospective, randomized, comparative investigation with blinded assessors. It was conducted at Ordu University Training and Research Hospital from December 1, 2022, to July 1, 2023.

CRITERIA FOR INCLUSION AND EXCLUSION:

Inclusion criteria were American Society of Anaesthesiologists (ASA) class I–II, patients aged 1–12 years, undergoing circumcision surgery, and patients with family consent. Exclusion criteria were patients without family consent, patients in whom regional anesthesia was contraindicated, patients with local infection at the injection site, degenerative neuropathy, coagulopathy, brain tumors, increased intracranial pressure, anatomical difficulties, mental retardation, and patients with a history of allergy to local anesthetics, chronic pain, and severe pulmonary, renal, and hepatic dysfunction.

THE DATA ACQUISITION PROTOCOL:

Circumcision surgery was performed in the operating room of the Department of Pediatric Surgery, Ordu University Training and Research Hospital. An experienced anesthetist performed a caudal block under ultrasound (US) guidance. The same anesthetist collected data in the operating room (intraoperative) and recovery room (0^th hour). The anesthetist knew which group the patient belonged to. However, the pediatric surgeon who collected data in the postoperative service (hours 1 and 4) and outpatient clinic (hour 24) did not know which group the patient belonged to.

RANDOMIZATION:

In this study, complete randomization was applied, and the sequentially numbered, opaque, sealed envelope (SNOSE) method was used as randomization technique. We employed the sealed envelope method to achieve randomization, guaranteeing unbiased allocation of participants to the study groups. To uphold the study’s integrity, a single-blind protocol was implemented. The anesthesiologist (EC) responsible for administering the blocks remained separate from the subsequent postoperative data collection. A different anesthesiologist (IC), unaware of the specific block performed, conducted the data collection, ensuring the blinded nature of the assessment.

ANESTHESIA MANAGEMENT:

Each patient who was accompanied to the operating room by their parents was asked if they had fasted for at least 6 h before surgery. Children who were premedicated with 0.07 mg/kg midazolam and 1 mcg/kg fentanyl were taken to the operating room. After standard monitoring, mask induction with sevoflurane was performed. The caudal block was performed under mask anesthesia. Mask anesthesia was maintained until the surgical incision. When the patient regained spontaneous breathing, mask anesthesia was discontinued and free oxygen was started. Intraoperative adverse effects such as tachycardia, bradycardia, desaturation, nausea, and vomiting were recorded. Patients were taken to the recovery room after surgery.

CAUDAL BLOCK PERFORMING:

A patient was placed in a lateral decubitus position and skin antisepsis was performed. A linear US probe (GE Logiq-e Nextgen model, General Electric Medical Systems, Phoenix, AZ, United States) (7–12 mHz) was used. The probe was first placed transversely (out of plane-short axis) over the sacral cornu in the midline. Sacral cornu, sacrococcygeal ligament, and sacral bone were examined, and anatomical structures were checked. Caudal block was not applied to patients with anomalies in caudal structures. The probe was then rotated 90 degrees and placed longitudinally (in plane-long axis), and the anatomical structures were re-examined. While the probe was in the long axis, the sacrococcygeal membrane was punctured with a 22 G-50 mm US visible nerve block needle (Echoplex, Vygon, Ecouen, France), and the sacral canal was located. Meanwhile, the visibility of the needle was monitored by US. After confirming the absence of cerebrospinal fluid or blood by negative aspiration, 0.5 ml/kg, 0.125% bupivacaine was administered. During the injection of the local anesthetic solution, expansion of the caudal epidural space or turbulent flow was observed by Doppler imaging.

PERIOPERATIVE ANALGESIA PLAN:

Group C cases received only caudal block without any other analgesic intervention. Group CP cases received 10 mg/kg intravenous paracetamol after caudal block, while group CM cases received 1 mg/kg intravenous meperidine after caudal block. In the postoperative period, if pain scores were 4 or higher, 10 mg/kg oral paracetamol syrup was administered as rescue analgesia.

OUTCOME MEASUREMENTS:

The primary outcome of the study was total analgesic consumption; the secondary outcomes were pain scores and time to first analgesic administration. Pain intensity was assessed by the FLACC (face, legs, activity, crying, and consolability) and Wong-Baker scores. They were used together in this study to ensure concurrent validity. The score calculated from 5 different categories determines the severity of pain for FLACC. The Wong-Baker pain score uses a visual scale and uses the patient’s facial expressions to assess pain. Pain scores, time of first analgesic administration (hours), total amount of analgesic administered (mg, 24 h), and adverse effects (nausea/vomiting, pruritus, and motor blockade) were monitored postoperatively in all patients. Postoperative pain monitoring was performed by the pediatric surgeon. Pain scores were assessed at 0, 1, 4, and 24 h. Thus, information on analgesic use and pain scores was gathered at 4 different times.

STATISTICAL ANALYSIS:

The data were analyzed using IBM SPSS v23. Agreement with the normal distribution was assessed using the Shapiro-Wilk test. The chi-square test was used to compare categorical variables by group. A one-way analysis of variance (ANOVA) or Kruskal-Wallis test was used to compare the parameters, and the Duncan test or Dunn’s test was used in post hoc evaluations. The results of the analysis were presented as the mean±SD for quantitative data. Categorical data (variance and median minimum-maximum) were presented as frequency (percentage). The significance level was set as P<0.050.

POWER ANALYSIS:

The sample size determination for this study relied on opioid consumption data obtained from a previous study [11]. Calculations were performed using the G*Power V. 3.1.9.6 software. A total of 90 cases, distributed evenly with 30 cases in each group, were determined to be necessary for this study, considering a 95% confidence level (1−α), a 90% test power (1−β), and an effect size of d=1.02. Considering the potential for dropouts and data loss, the study aimed to enroll 41 patients in each group as part of the planned sample size.

Results

Of the 132 patients planned to be included in the study, 9 were not taken into surgery due to an upper-respiratory tract infection. A total of 123 patients were randomly divided into 3 groups: 41 were in Group C, 41 in Group CP, and 41 in Group CM. However, a total of 3 patients, 1 from each group, were excluded from the study for different reasons. Therefore, 40 patients were analyzed for each group. Figure 1 displays as the CONSORT diagram and delineates the enrollment process for this study.

Significant results were obtained when the group weight and age variables were analyzed. The results are presented in Table 1 (P values, P=0.011, and P=0.003, respectively).

There were no significant differences observed between the groups in the ASA class (P=0.050). When the presence of adverse effects was investigated, no statistically significant relationship was found between the groups in terms of intraoperative adverse effects and postoperative adverse effects (P=0.104 and P=0.050, respectively). The results are presented in Table 2.

Among the time periods measured according to the groups, only the 24th h Wong-Baker pain scores were significantly different (P<0.001). There was no significant difference in FLACC and Wong-Baker pain scores in other periods. The results are shown in Table 3, Figures 2 and 3.

There was no difference between the postoperative hours in which analgesics were administered and the total amount of analgesics (rescue analgesic 10 mg/kg oral paracetamol) by groups (P=0.408 and P=0.238, respectively). The results are shown in Table 4 and Figure 4.

Discussion

LIMITATIONS:

Our study has some limitations. First, the cases could not be categorized in terms of age group. Perhaps it may be more useful to categorize ages (eg, 0–3 years, 3–6 years, 6–9 years) in similar studies to be conducted in the future. The second limiting factor is that we evaluated pain scores only in the first 24 h postoperatively.

Conclusions

The addition of intravenous paracetamol or intravenous meperidine to a single caudal block was not superior to a caudal block alone in terms of analgesic requirement or total analgesic consumption and did not contribute to the quality of analgesia. Caudal block may be preferred for postoperative analgesia in circumcision surgery.