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 Table of Contents  
Year : 2019  |  Volume : 33  |  Issue : 2  |  Page : 94-99

Retrospective analysis of regional anesthesia techniques employed for postoperative pain management in pediatric patients undergoing pyeloplasty

1 Department of Anaesthesia and Critical Care, Command Hospital (Southern Command), Pune, Maharashtra, India
2 Department of Community Medicine, Armed Forces Medical College, Pune, Maharashtra, India
3 Department of Paediatric Surgery, Command Hospital (Southern Command), Pune, Maharashtra, India

Date of Submission27-Mar-2019
Date of Decision14-Apr-2019
Date of Acceptance31-May-2019
Date of Web Publication7-Aug-2019

Correspondence Address:
Dr. Deepak Dwivedi
Department of Anaesthesia and Critical Care, Command Hospital (Southern Command), Pune - 411 040, Maharashtra
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijpn.ijpn_27_19

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Context: Pediatric pain management is always a challenge for the anesthesiologist as surgery and pain inflicted at a young age has a bearing on the response to pain in the future. Aims: The aim of the study was to compare the different regional anesthesia techniques adopted for the postoperative pain relief in children aged between 6 months and 6 years who underwent open pyeloplasty. Settings and Design: It was a retrospective study. Materials and Methods: Children were divided into three groups: caudal group (n = 18), epidural group (n = 23), and transversus abdominis plane (TAP) group (n = 32) based on the regional anesthesia technique used. The primary outcome measured was total duration of postoperative analgesia. The secondary outcomes measured were median Face, Legs, Activity, Cry, Consolability (FLACC) score, intraoperative and postoperative heart rate, and mean arterial pressure along with incidence of any complication. Statistical Analysis Used: One-way ANOVA and Kruskal–Wallis test were applied for comparison between the three groups. Results: Postoperative analgesia duration in minutes was highest in the epidural group (1117.3 ± 112.2), followed by TAP group (1070.0 ± 109.3) and caudal group (261.5 ± 18.2). Median FLACC pain scores achieved at 12 and 24 h were least in the epidural group, followed by the TAP and caudal groups. Conclusions: Epidural analgesia is best suited in terms of the duration as well as the quality of postoperative analgesia is concerned, but surgeon-assisted TAP block looks promising and a feasible option with comparable postoperative analgesia quality and duration.

Keywords: Caudal anesthesia, epidural analgesia, pain management, pediatrics

How to cite this article:
Dwivedi D, Sawhney S, Sud S, Dudeja P, Raman S, Dey S. Retrospective analysis of regional anesthesia techniques employed for postoperative pain management in pediatric patients undergoing pyeloplasty. Indian J Pain 2019;33:94-9

How to cite this URL:
Dwivedi D, Sawhney S, Sud S, Dudeja P, Raman S, Dey S. Retrospective analysis of regional anesthesia techniques employed for postoperative pain management in pediatric patients undergoing pyeloplasty. Indian J Pain [serial online] 2019 [cited 2021 Sep 19];33:94-9. Available from: https://www.indianjpain.org/text.asp?2019/33/2/94/264074

  Introduction Top

Pediatric pain management has always been a challenge for an anesthesiologist.[1] However, with increased use of regional anesthesia as a sole technique or in conjunction with the general anesthesia (GA), the postoperative pain scores achieved are better which in turn lead to a lesser anxiety among children and improve the outcome.[2],[3] Postoperative pain has an adverse pathophysiologic phenomenon which affects the immune and stress response to surgery as well as results in the complex maladaptive behavior pattern in children.[4],[5] Sensitization to pain occurs both at the peripheral level (spinal level) and at the central level which governs the future response to the noxious stimulus.[6] The aim is to prevent the sensitization of the neurons, and this can be done with incorporation of the various regional techniques, locoregional anesthesia, and drugs acting on different receptors of pain. This study was undertaken retrospectively to compare the modalities of pain relief adopted in children who underwent pyeloplasty under GA.

  Materials and Methods Top

A retrospective study was planned after the concurrence being obtained from the Institutional Ethical Committee to compare the postoperative analgesia duration in children who were administered different types of regional anesthesia techniques along with GA for pyeloplasty. Written informed consent was obtained from all the parents before the surgery. Waiver for the consent of the study was given by the ethical committee as the study being a retrospective study involving only the analysis of the data from the central anesthesia registry. The data of children who underwent pyeloplasty from January 2016 to December 2018 were included in the data analysis.

Inclusion criteria included children aged between 6 months and 6 years who had undergone pyeloplasty under GA and were offered regional anesthesia in the form of either continuous epidural analgesia at the level of T12/L1 vertebrae, continuous transversus abdominis plane (TAP) block, or caudal block. All American Society of Anesthesiologists physical status Class I and II children were also included. Children aged >7 years undergoing pyeloplasty, without any supplementary regional analgesia technique and with a history of allergy to any of the local anesthetic drugs, local site infection, and spinal dysraphism with spinal and meningeal anomalies were excluded from the analysis.

All patients were administered GA by the standard technique which included premedication with injection glycopyrrolate 4 μg/kg, injection fentanyl 2 μg/kg, and injection midazolam 0.05 mg/kg intravenously (IV), followed by induction with injection propofol 2 mg/kg IV. Airway was secured with the appropriate size cuffed/uncuffed endotracheal tube after the administration of injection atracurium 0.5 mg/kg IV. Maintenance was done with the oxygen, air, and sevoflurane targeting the minimum alveolar concentration of 1.2. Standard monitoring was being used in all the cases which included capnogram, noninvasive blood pressure, electrocardiogram, and pulse oximetry. After the GA, all children were administered either continuous epidural or caudal block. Surgeon-assisted continuous TAP block was given just before the closure of the muscle layers to augment the postoperative analgesia. Intraoperatively, all the children received paracetamol (15 mg/kg) IV. Anesthesia was reversed with the injection neostigmine 50 μg/kg and glycopyrrolate 10 μg/kg IV. In immediate postoperative period, the pain score (Face, Legs, Activity, Cry, Consolability [FLACC] score) was noted and being followed up in the postoperative ward every 2-h interval until 6 h and then every 6-h interval until 24 h, and the score was entered in the anesthesia records of each patient separately as per the institutional protocol of record keeping.

FLACC Behavioral Pain Assessment Scale developed by Merkel et al. is a very popular and frequently used scale for assessing postoperative pain in infants and children.[7] Every assessment involves observing the patients for 1–5 min by uncovering them and noticing their body posture, position of legs, activity level, expression of face, body tenseness, and tone. Each category is scored on the 0–2 scale, with total score of 0–10. Score of 0 means relaxed and comfortable patient, score of 1–3 is mild discomfort, score of 4–6 is moderate pain, and score of 7–10 is severe discomfort or pain or both.[7]

Patients were divided into three groups depending on the technique of regional anesthesia used: Group A (single-shot caudal block), Group B (continuous epidural block), and Group C (continuous unilateral TAP block). The primary outcome measure included duration of postoperative analgesia which was defined as the time of requirement of the first dose of rescue analgesia (injection paracetamol 15 mg/kg IV slow infusion) when the pain score (FLACC) exceeded more than three. The secondary outcomes recorded were median FLACC score at immediate postoperative period and at 2 h, 6 h, and 12 h, and 24 h postoperatively. Mean arterial pressure (MAP) and heart rate (HR) both were measured as the secondary outcomes, and the values at the time of incision and in the immediate postoperative period were compared with the baseline values. Postoperative complications if any were also recorded.

Caudal block

A patient was positioned in the lateral position after intubation, cleaning, and draping were done. After draping the back with the sterile towel, caudal epidural space was identified by anatomical landmarks (sacral hiatus). Using 25-mm needle caudal epidural space was entered, and after negative aspiration for cerebrospinal fluid (CSF) and blood, 1.2 ml/kg of volume of local anesthetic 0.2% ropivacaine (not exceeding the maximum dose as per body weight) was administered [Figure 1]a.
Figure 1:(a) A 25-mm needle in the caudal space. (b) The 19G epidural needle in the T12–L1 space

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Epidural analgesia technique

A child was positioned in the lateral position after intubation, cleaning, and draping with the sterile towel were done. Intervertebral space T12/L1 was identified by the anatomical landmarks, and a 19G epidural needle was introduced under strict aseptic precautions; the epidural space was confirmed by the loss of resistance to saline. A 20G epidural catheter was threaded through the Tuohy's needle, and after the negative aspiration for CSF and blood, the catheter was fixed and the sterile dressing was applied [Figure 1]b. A bolus of 0.5 ml/kg of 0.2% ropivacaine was given immediately before the surgical incision, and the continuous infusion of 0.2 ml/kg/h of 0.1% ropivacaine was started before the closure of the surgical wound.

Surgeon-assisted transversus abdominis plane block

After the completion of surgical procedure, a plane was created between the internal oblique and the transversus abdominis muscle by the blunt dissection. A 19G epidural needle was entered in the plane between the two muscles; a 20G epidural catheter was introduced through the needle in the plane under direct vision by the surgeon, and the catheter was tied and secured to the skin by sutures [Figure 2]. After closure of the skin, 0.3 ml/kg of 0.2% ropivacaine was given as bolus before extubation, and a sterile dressing was applied, followed by continuous infusion of the TAP block at the rate of 0.2 ml/kg/h of 0.1% ropivacaine.
Figure 2: The epidural catheter placed in the transversus abdominis plane

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Statistical analysis

Data were compiled in Excel sheet and analyzed in IBM SPSS for windows, version 23.0 (SPSS Inc, Chicago, Illinois, USA). Mean and standard deviation (SD) were calculated for HR and MAP. Median was estimated for FLACC score. For comparison of different groups, one-way ANOVA and Kruskal–Wallis test were applied.

  Results Top

A total of 100 patients were screened. The total number of cases meeting the inclusion criteria in caudal, epidural, and TAP group was 18, 23, and 32, respectively. There was no difference between the three groups with respect to weight, age, and duration of surgery. However, the duration of postoperative analgesia was significantly higher in the epidural group as compared to the caudal and TAP groups (P < 0.05) [Table 1].
Table 1: Comparison of weight, age, duration of surgery, and postoperative analgesia in three groups

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The comparison of HR and MAP was done between the groups at baseline, the time of incision, and immediate postoperative period [Figure 3] and [Figure 4]. Mean (SD) values of HR in the caudal group (110.8 [11.1]), epidural group (107.5 [12.5]), and TAP group (131.3 [12.4]) at the time of incision showed a statistically significant difference (P = 0.00). Mean (SD) values of MAP when compared between the three groups, i.e. caudal (61.2 [4.3]), epidural (63.9 [5.5]), and TAP (80.2 [7.8]), also showed significant results (P = 0.00). Median of FLACC scores when compared between the three groups at baseline and at 2 h, 6 h, 12 h, and 24 h revealed higher median scores in the caudal group when compared with the remaining two groups from 6 h onward postoperatively [Table 2]. None of the group had any incidence of complications.
Figure 3: Error bar diagram with confidence interval of means for heart rate in three groups (caudal, epidural, and transversus abdominis plane) at baseline, time of incision, and postoperatively

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Figure 4: Error bar diagram with confidence interval of means for mean arterial pressure in three groups (caudal, epidural, and transversus abdominis plane) at baseline, time of incision, and postoperatively

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Table 2: Comparison of median Face, Legs, Activity, Cry, Consolability scores between the three groups

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  Discussion Top

Effective perioperative pain management is essential, as pain leads to activation of sympathetic and adrenocortical system resulting in increase in the perioperative morbidity, delayed recovery, prolonged stay, and increased children and parents' anxiety.[8] Acute postoperative pain is an independent risk factor for developing persistent postsurgical pain in children.[9],[10] Inadequately treated pain causes emotional, psychological, and physical trauma to children as well as to their caregivers.[11] Pyeloplasty surgery involves dorsal lumbar incision or flank incision involving T10–L2 dermatome with considerable amount of pain in the postoperative period.[12] Multimodal approach for the perioperative pain management in the pyeloplasty patients constitutes administration of paracetamol, opioids, epidural analgesia, caudal analgesia, and regional blocks such as TAP blocks.[13],[14]

Caudal analgesia is a well-established technique for providing analgesia in both supraumbilical and infraumbilical surgeries and can be further supplemented with adjuvants such as morphine, fentanyl, and clonidine.[15],[16] Caudal analgesia supplemented with low dose of morphine in children for renal surgery had shown a prolonged duration of analgesia with minimal side effects and favorable pain scores when compared with the sole caudal analgesia technique using local anesthetic.[14] In our study, the caudal analgesia was used without the additives, and therefore, the mean (SD) duration of analgesia was much shorter [Table 1]. The continuous caudal block can be used for prolonging analgesia, but due to the risk of bacterial colonization of the catheter and its propensity for misplacement, this technique is not preferred in our institute.[17],[18] The intraoperative hemodynamics in the caudal group were better maintained when compared with the TAP group but less than the epidural group [Figure 3] and [Figure 4].

Epidural analgesia is a well-proven technique for providing intraoperative and postoperative analgesia in the pediatric population, but with the advent of the other modalities of the pain relief, it has been overtaken by other options such as caudal analgesia with additives, peripheral blocks, and patient-controlled analgesia.[19] Our results also show that in majority number of patients, TAP block was chosen as the component of multimodal analgesia [Table 1]. In wake of the advances in the pain management, the indications for the pediatric epidural have become very defined comprising mainly in spine surgeries and major open abdominal as well as thoracic surgeries.[20] Meta-analyses have enough evidence in favor of improved pain scores with pediatric epidural analgesia.[21],[22] Results of our study show good postoperative analgesia duration with lower median FLACC scores till 24 h measured at regular intervals [Table 1] and [Table 2]. Substantial advantage with the continuous pediatric thoracic epidural occurs during the intraoperative period where it has a positive impact on the intraoperative hemodynamics due to its proven role in reducing the stress response and providing the continuous analgesia[23] [Figure 3] and [Figure 4]. Improved patient outcome in terms of decreased hospital stay and postoperative morbidity such as respiratory complications, nausea, and vomiting has already been established.[23] Various audits done to ascertain the risks and complications with pediatric epidural analgesia had varied results with the incidence varying between 1:2000 and 1:10,000.[24] The incidence of complications is higher in the neonatal period extending up to the first 6 months of age due to its potential to injure the growing cartilage.[25] Our study included children beyond 6 months of age, and only in one case, inadequate postoperative analgesia resulted with higher FLACC score requiring the supplementation with injection fentanyl IV (0.5 μg/kg) in the immediate postoperative period and was excluded from the study.

Ultrasound-guided TAP block has established its role in ameliorating the pain in the perioperative period in adults with a good safety margin and high success rates. It has become an integral part of the multimodal analgesia model finding its application in wide arrays of surgeries including open as well as laparoscopic abdominal surgeries. TAP block in the pediatric population has been employed for appendectomy, herniorrhaphy, colostomy closure, and laparotomy.[26],[27] Ultrasound-guided TAP block has high success rates with minimal complications in the pediatric age group.[28]

Surgeon-assisted TAP blocks have also been described in the literature which includes laparoscopic-assisted TAP block, a transperitoneal approach, and an open technique as described by Araco et al., where before the closure of the abdominal muscle layers, a plane is created between the internal oblique and the transversus abdominis by the blunt dissection, and the local anesthetic solution is administered under direct visualization.[27],[29] In our study, surgical TAP block was administered as described by the Araco et al., but instead of only deposition of local anaesthetic solution by them in the transversus abdominis plane, we placed the catheter under vision for continuous TAP block. Few pediatric studies exist which describe the continuous TAP block, and there exists variation in the dose of the infusion.[27] Bakshi et al. have used surgically assisted pediatric continuous TAP block in an urgent pediatric laparotomy with the prolonged postoperative pain relief.[30] The single-shot dose varies between 0.2 and 0.5 ml/kg in most of the studies.[13],[28],[31] Taylor et al. have used loading dose of 0.3 ml/kg of 0.25% bupivacaine through TAP catheter, followed by the infusion of 0.1% bupivacaine at the rate of 4 ml/h for the bladder surgery in the patients with spinal dysraphism with good perioperative analgesia.[31] We have used 0.3 ml/kg of 0.2% ropivacaine as a loading dose, followed by the continuous infusion of 0.2 ml/kg/h of 0.1% ropivacaine with very good postoperative analgesia with the median FLACC scores comparable to the epidural group at all time intervals [Table 1] and [Table 2]. EI Fawy et al. compared ultrasound-guided TAP block with caudal block as a modality for the postoperative pain relief in children who underwent pyeloplasty and concluded that unilateral TAP block provides good analgesia when compared with the caudal block without additives within 24 h.[13]

Evolving trend nowadays shows shift from neuraxial blockade to regional blocks with widespread use of the real-time ultrasonography. Surgical TAP block can prove to be a feasible and safe alternative for efficient postoperative pain relief without attendant risk of the neuraxial techniques. Further, this technique has a similar advantage as epidural for providing prolonged analgesia. This modality could be used both as a continuous and nurse/patient-controlled analgesia.

Strength of this study lies in providing an insight into the regional anesthesia techniques employed for the postoperative pain relief in children undergoing pyeloplasty. This will help in selecting an appropriate modality of regional block in such subsets of pediatric surgery.

The study being a retrospective study is a major limitation as it requires a larger study population to draw concrete inferences with selection bias of the patient which cannot be completely ruled out.

  Conclusion Top

Continuous epidural analgesia provides stable hemodynamics with prolonged postoperative analgesia when compared with the caudal block and surgeon-assisted continuous TAP block. However, surgeon-assisted continuous TAP block can be a feasible option if combined with the preincision USG-guided TAP Block as it only lacks in attenuating the stress response intraoperatively. Single-shot caudal block administered before incision is limited by its duration of analgesia.

In view of the varying practices in providing postoperative analgesia in pediatric patients, the European Society of Paediatric Anaesthesiologist has come out with a novel approach of formulating standard pain management ladder targeting most common pediatric surgical conditions.[1] This step will enable us to facilitate standardized practices among the pediatric anesthesiologist, thereby widening the horizons for future research in pediatric pain management.

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Conflicts of interest

There are no conflicts of interest.

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[PUBMED]  [Full text]  
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  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1], [Table 2]


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