Role of Pre-incisional Bupivacaine Infiltration in Post-tonsillectomy Analgesia

Abstract

Tonsillectomy is one of the common surgeries performed by Otorhinolaryngologists and is associated with several morbidities with pain being the commonest, which can cause considerable delay in oral intake and discharge from the hospital. As a commonly performed day care procedure nowadays, pain control is much better than what it used to be previously observed. Therefore newer drugs are being constantly studied inorder to give better analgesia and post operative comfort to the patient with minimal side effects. The main obstacle being finding the best medical method to control pain with minimum side effects, but at the same time making sure that the patient is adequately hydrated and they resume regular eating as soon as possible. Our aim is to study the role of pre-incisional 0.5% bupivacaine versus normal saline infiltration in post-tonsillectomy analgesia. Over a period of 1 year, 30 patients with each group of 15 were compared for the efficacy of 0.5% bupivacaine and 0.9% normal saline in post-operative tonsillectomy pain management. After thorough clinical examination and investigations, all patients underwent tonsillectomy by dissection and snare method. After intubation, 0.5% bupivacaine or normal saline was infiltrated in the tonsillar fossa and pain scores was obtained using Visual Analogue Scale (V.A.S) at 6, 12 and 24 h post operatively. Using Mann–Whitney non-parametric statistical test, inter-group analysis was done which showed highly significant p-value (<0.0001) indicating that the pre-incisional bupivacaine infiltration is highly effective in reducing the post-tonsillectomy pain. Hence, we recommend the routine use of pre-incisional peritonsillar infiltration of 0.5% bupivacaine in all tonsillectomy/adenotonsillectomy cases, irrespective of the age of the patient to reduce the post tonsillectomy pain and other discomfort associated with it.

Introduction

Tonsillectomy is a surgery being performed over 2000 years, Celsus was the first to report removal of the tonsils. Describing his surgical technique, Celsus indicated that "the tonsils are loosened by scrapping around them and then torn out”. Later however, Mackenzie improved on the Tonsillotome and popularized its use for surgery of the tonsils in the late nineteenth century. Since then this surgery has evolved to newer dimensions [1].

It is one of the common surgeries performed by otorhinolaryngologists around the globe. Tonsillectomy is associated with several morbidities with pain being the commonest, which can cause considerable delay in oral intake and discharge from the hospital. Post-operative pain management is a major challenge, obstacles include finding the best post-operative medical method to control pain with minimum side effects at the same time making sure patient is adequately hydrated and they resume regular eating as soon as possible.

Although children receive analgesics for pain control, operative pain remains a significant problem that is often undertreated in the paediatric population for several reasons. Children often refuse analgesics because the medication is not palatable or causes adverse effects such as nausea, vomiting, or somnolence. In addition, parents may not always recognize that a child is suffering because the child does not complain, but rather withdraws or becomes depressed.

Prevention of pain perception may be a key factor in the management of postoperative pain. Several studies have shown that the analgesic effects of local anaesthetics applied prior to injury far outlast the effects of local anaesthetics instilled following injury [2–5].

In the light of the problems associated with post-operative pain, various strategies for the management of post tonsillectomy pain have been proposed. Local anaesthetics in the form of pre-incisional or post-incisional peritonsillar infiltration and also topical post-incisional spray or packing are some of the most effective methods for post-tonsillectomy pain management, although some studies refute their use. This has also led to advent of use of other methods of tonsillectomy which include micro-debrider, coblation tonsillectomy, radio-frequency ablation, harmonic scalpel and laser tonsillectomy.

The present study assesses the effect of bupivacaine in blocking nociceptive input and reducing pain during the immediate post-operative period.

Objective

To study the role of pre-incisional bupivacaine infiltration in post-tonsillectomy analgesia, in-patients undergoing tonsillectomy at KLES’ Dr Prabhakar Kore Charitable Hospital, Belagavi, Karnataka, India.

Material and Methods

Study Design

Observational study.

Study Period

January 2019 to December 2019.

Source of Data

All patients between age group of 6 to 16 years with chronic tonsillitis or chronic adenotonsillitis attending the outpatient department of ENT, KLES Dr.Prabhakar Kore hospital during the study period and willing to undergo surgery for the same were included in the study.

Sample Size

30 cases (15 in each group)

Inclusion Criteria

All patients undergoing Tonsillectomy in the age group between 6 to 16 years.

Exclusion Criteria

Patients allergic to Bupivacaine and those patients who were not willing to be part of the study.

Methodology

Patients details and a thorough clinical history was obtained for the duration of symptoms. All patients were clinically examined including general physical examination and a thorough examination of the ear, nose and throat.

All the patients (30) were divided into 2 groups randomly:

• Group 1: In this group the patients (15) received 2.5 ml 0.5% bupivacaine hydrochloride in each tonsillar fossa. A total of 5 ml was injected.

• Group 2: In this group the patients (15) received 2.5 ml of 0.9% normal saline in each tonsillar fossa. A total of 5 ml wa0s injected.

• Pre-operatively, patients were explained about the correct use of Visual Analog Scale (V.A.S.) since the study involved direct questioning [6].

• Post-operative pain assessment was done using V.A.S at 6, 12 and 24 h post operatively:

• After intubation, peritonsillar infiltration was be given at 3 points: upper pole, lower pole and tonsillar fossa, a total of 2.5 ml was injected in each fossa.

• Tonsillectomy was perfomed using dissection and snare method.

• Post-operative pain was measured using V.A.S in both the groups at 6 hr, 12 hr and 24hrs periods [6].

Data analysis was done measuring mean of all observations, Wilcoxon test and Mann–whitney test wherever applicable.

Results

Out of a total 30 cases, 17 (56.7%) were male and 13 (43.3%) were female. The patients were between 7 to 16 years of age. The mean age was found to be 10.13 years in Group-1 and 13.13 years in Group-2. Table 1 shows the gender wise distribution of patients into two groups. Group-1 had 9 (60%) male patients and 6 (40%) female patients whereas Group -2 had 8(53.33%) male patients and 7 (46.67%) female patients.

Table 1.

Distribution of male and female patients in two groups

Gender	Group-1 (0.5%bupivacaine)		Group-2 (normal saline)
	Number	Percentage	Number	Percentage
Female	6	40.00	7	46.67
Male	9	60.00	8	53.33
Total	15	100.00	15	100.00

Using Mann–whitney non-parametric statistical test, inter group analysis was done showing highly significant p-value indicating that the pre-incisional bupivacaine infiltration(Group1) is highly effective in reducing the post-tonsillectomy pain as seen in the Fig. 1 and Table 2.

Fig. 1.

Graph showing Inter group comparison using visual analogue scale at different time intervals (Group 1 – 0.5% bupivacaine, Group 2 = normal saline)

Table 2.

Inter group comparison using visual analogue scale at different time intervals (Mann–Whitney Test)

Time	Median		p value	Inference
	Group 1 (0.5%bupivacaine)	Group 2 (normal saline)
6 h	5	9	<0.0001	HS (Highly Significant)
12 h	4	8	<0.0001	HS (Highly Significant)
24 h	3	7	<0.0001	HS (Highly Significant)

Discussion

The notion of pre-emptive analgesia was introduced by Woolf in 1983, to reduce the intensity and duration of postoperative pain. Following this, there was an overwhelming amount of experimental data which provided numerous ways of anti-nociceptive techniques which when applied before surgery was effective in reducing the post operative pain. Eventually, these promising experimental findings were taken into clinical testing to prove this hypothesis. At present, clinicians do believe the efficacy of pre-emptive analgesia, even though some early reviews did prove to be contradictory. In this study, we compared the effect of bupivacaine in reducing post-operative pain [7].

This was a comparative study done in a total of 30 patients, who were admitted for Adenotonsillectomy or Tonsillectomy, after acquiring institutional consent from the Institutional Ethics Committee.

All patients underwent Cold knife (steel) Dissection and snare method of tonsillectomy, and patients were observed in post-operative ward during which pain score was analysed using V.A.S. Post-operative pain at 6hours, 12hours, 24hours respectively in both the groups.

Bhadoria et al., conducted a double blind randomized study involving 38 patients with ASA grade I (American Society of Anaesthesiologists) status, from age group 6–16 years and divided them into groups of 19 each, with mean age 10.6 ± 0.5 years in both groups. Bupivacaine and normal saline was compared in this study. On comparison it showed that patients receiving bupivacaine showed better pain relief at 2nd and 6th hour postoperatively. The patients were comfortable and this was assessed in terms of no significant tachycardia or hypertension [8]. Wong et al. analysed 43 children in three groups between the age group of 2–10 years with ASA grade I and II with no bupivacaine allergy. 1st group received 0.5 mg/kg normal saline spray, 2nd group received 2 mg/kg bupivacaine with 1:200,000 epinephrine by infiltration and the 3rd group received 2 mg/kg bupivacaine with 1:200,000 epinephrine sprayed on the tonsil. The study concluded that infiltration of bupivacaine provided better pain relief and a lower pain score of 4.8 when compared to 7.8 and 7.4 for normal saline spray and bupivacaine spray respectively [9].

Ehab Said conducted a study on preincisional infiltration with bupivacaine, tramadol, ketamine alone and in combination in 180 patients. All patients received infiltration with 2 ml of the drug, 1 ml in each tonsillar fossa and superior pain management was found in bupivacaine and tramadol when used in combination [10].

Gupta et al., did a study on 60 patients aged between 15 to 40yrs, and 3 groups were studied. 1st group received preoperative Diclofenac sodium, 2nd group received preincisional infiltration of bupivacaine and 3rd group received post tonsillectomy Transcutaneous Electric Nerve stimulation (TENS). Patient scores were recorded using VAS, and it was studied that rescue analgesia was less used in TENS followed by Bupivacaine and lastly using Diclofenac [11]. Bhatia and Patel, conducted a randomized double binded study on pediatric patients wherein one group received bupivacaine and the other group received normal saline. Bupivacaine infiltration had better pain management, with analgesia lasting for 6 to 8 h post operatively [12]. Kannntakis, conducted a study on 30 patients over a period of 2 years, divided them into 2 groups, and compared bupivacaine with normal saline. It was concluded that initial pain management was better with bupivacaine infiltration and oral analgesics were less consumed post operatively but after the 3rd day, it was observed that the patients started consuming same or higher amount of analgesics compared with the normal group. Thus, it was inferred that in a 10 day study, bupivacaine does not prove to be better analgesic [13].

Our study confirms the similar results with most of the previously conducted studies in addition to assessing the VAS scores upto 24 h post operatively. In the immediate post-operative period, when the pain is more, the effect of infiltration with bupivacaine proved to be of benefit to the patients. As most of the patients were dischatged from the hospital on the 2nd post operative day when they started feeding better, all our patients did not complain of pain during their follow up visits. This suggests that in an uncomplicated case of tonsillectomy, it is important to provide adequate analgesia during the first 24 h as after that, the patients tend to overcome the symptom due to better feeding and resumption of movement of muscles in the oropharynx which probably helps to ward off the inflammatory mediators.

Conclusion

Nociceptive blockage during the initial post-operative period following tonsillectomy was effective with 0.5% bupivacaine, reducing morbidity caused by pain. It is also effective in starting early oral feeds and discharge from hospital. Since we did not encounter any adverse effects associated with 0.5% bupivacaine, it is hereby recommended to routinely use pre-incisional peritonsillar infiltration of 0.5% bupivacaine in all tonsillectomy / adenotonsillectomy cases, irrespective of the age of the patient to reduce the post tonsillectomy pain and discomfort associated with it.

Availability of Data and Material

Not applicable.

Code Availability

Not applicable.

Compliance with Ethical Standards

Conflicts of interest

The authors declare that they have no conflict of interest.

Ethics Approval

Approval was obtained from the ethics committee of KLE Academy of Higher Education and Research. The procedures used in this study adhere to the tenets of the Declaration of Helsinki.

Consent to Participate

Written informed consent was obtained from the relatives/ legal guardians of the study participant.