Role of Thoracic Epidural Anesthesia in Providing Adequate Intraoperative and Postoperative Opioid-free Analgesia for Breast Cancer Surgeries

Abstract

Background:

Breast cancer is the most common malignancy in women. Postoperative pain and opioid analgesics are suspected to influence cancer recurrence. In this study, we try to assess the feasibility of providing complete opioid-free surgical anesthesia and postoperative analgesia for breast cancer surgeries.

Methodology:

This prospective observational study was performed on 30 patients posted for breast cancer surgery under thoracic epidural anesthesia. The epidural catheter was placed in the upper thoracic space. A titrated bolus of 10–12 mL of 2% lignocaine with adrenaline followed by an infusion of 0.2% ropivacaine at 5–10 mL/hour was used. Time taken from epidural bolus to skin incision, the total dose of local anesthetic and propofol required, postoperative pain score, the patient and surgeon satisfaction score, and adverse events were noted.

Results:

Opioid-free epidural anesthesia was successful in all patients. The average time required to start the surgery after placement of the epidural catheter was 17.8 ± 2.5 min. The average total dose of local anesthetic and propofol supplemented was 6.9 ± 4.5 mL and 18.9 ± 11.8 mg, respectively. Postoperative pain scores were <4 at all time points. The average surgeon and patient satisfaction scores were 9.1 ± 0.2 and 9.1 ± 0.2, respectively. Thirteen percent of patients required treatment for hypotension. There were no episodes of bradycardia or airway compromise.

Conclusions:

Based on our data, it appears to be safe to perform opioid-free breast cancer surgeries under thoracic epidural anesthesia with complimentary sedation and local infiltration. Epidural infusion of local anesthetic provides excellent intra- and postoperative analgesia, which helps avoid the use of opioids.

INTRODUCTION

Breast cancer surgeries are one of the frequently performed surgeries in females.[1] Various regional anesthesia techniques like intercostal nerve block, erector spinae block, and paravertebral and pectoral nerve blocks are used to provide postoperative analgesia after breast cancer surgeries.[1,2] Retrospective studies have shown that cancer outcomes could be altered by the choice of anesthetic used.[3,4] Postoperative pain and opioid analgesics are suspected to influence cancer recurrence.[5] In this study, we try to assess the feasibility of providing complete opioid-free anesthesia and postoperative analgesia for breast cancer surgeries with thoracic epidural anesthesia. The primary objective was to assess the anesthetic efficacy by determining the total number of cases that required conversion to general anesthesia. The secondary outcome measures were the time to achieve complete surgical anesthesia with an epidural catheter, hemodynamic instability, propofol used, postoperative pain score, and patients’ and surgeons’ satisfaction score.

METHODOLOGY

This prospective feasibility study was performed after obtaining ethical clearance from the hospital ethics committee, CTRI clearance (CTRI/2021/04/032930) and written informed consent from patients. The study was conducted in accordance with the principles of the 2013 Declaration of Helsinki from April 2021 to June 2023. Thirty American Society of Anesthesiologists Physical Status II patients between the age group of 18 and 65 years posted for modified radical mastectomy with axillary clearance in a tertiary care hospital were recruited. Patients not consenting for epidural anesthesia, on anticoagulant drugs, psychiatric illness, allergy to local anesthetic, and local infection at the site of epidural placement were excluded from the study.

All patients underwent preanesthetic evaluation, were kept fasting for 6 h, and were premedicated with tablet pantoprazole 40 mg and tablet alprazolam 0.25 mg 2 h before surgery. In the operating room, baseline monitors (5-lead electrocardiogram, noninvasive blood pressure, and saturation probe) were attached. Intravenous access was secured in the nonoperating sidearm, and 500 mL of ringer lactate was transfused. All epidurals were placed by a single consultant anesthetist, and a consultant oncosurgeon with >10 years of surgical experience performed the performed the surgeries. Under strict aseptic precautions, an epidural catheter was placed in the upper thoracic space (T5–T6/T6–T7) using an 18G Tuohy needle. The epidural catheter was threaded 4 cm into the epidural space in the cephalad direction. A test dose of 3 mL of 2% lidocaine and 1:200,000 adrenaline was given. After confirming the absence of intravascular and intrathecal placement, epidural anesthesia was achieved using a titrated bolus of 8–10 mL of 2% lignocaine with 1:200,000 adrenaline and 1 mL of soda bicarbonate to achieve adequate block. After 30 min, an infusion of 0.2% ropivacaine at 5–10 mL/hour was started. Sensory blockade achieved was assessed with ice cubes 15 min after epidural bolus injection. If adequate block was not achieved within 30 min, it was considered as block failure and general anesthesia was given. Time taken from epidural bolus to skin incision was noted.

If the patient complained of pain or discomfort during surgery, supplemental local infiltration of 2% lignocaine with 1:200,000 adrenaline was given by the surgeon and intravenous propofol in boluses of 10 mg was used. The total dose of local anesthetic and propofol required was noted. The patients’ heart rate, mean blood pressure, and SpO₂ were noted every 5 min throughout the surgery. Bradycardia was defined as a heart rate >50 beats/min and was managed with intravenous atropine 0.6 mg. Hypotension was defined as 20% fall in mean arterial pressure from baseline and was managed with 250 mL fluid bolus and ephedrine as 3 mg intravenous boluses. Postoperative pain was assessed by the postoperative nurse at 1, 4, and 12 h using a 10-point numeric pain scale (0 – no pain, 10 – worst possible pain). Patients with a pain score of >3 were given intravenous paracetamol 1 g. Patients complaining of nausea and vomiting was treated with intravenous ondansetron 8 mg. At the end of the surgery, the patient’s and surgeon’s satisfaction scores were assessed as a 10-point satisfaction score, where 0 was unsatisfied and 10 most satisfied. Any adverse events associated were also noted.

Statistical analysis was done using IBM SPSS 20 (SPSS Inc., Chicago, USA). For all the continuous variables, the results were given in mean ± standard deviation and categorical variables as percentage.

RESULTS

We recruited 30 patients in this study [Figure 1]. The demographic data of patients included were comparable [Table 1]. Opioid-free epidural anesthesia was successful in all patients and no patient required conversion to general anesthetic. The average time required to start the surgery after placement of epidural catheter was 17.86 ± 2.574 min. The average total dose of local anesthetic required to be supplemented was 6.90 ± 4.515 mL. The average intravenous propofol supplementation required was 18.97 ± 11.880 mg [Table 2]. Postoperative Visual Analog Scale scores at 1, 4, and 12 h in the postoperative period were 1.31 ± 0.660, 1.45 ± 1.021, and 1.31 ± 1.004, respectively. The average surgeon and patient satisfaction score was 9.14 ± 0.163 and 9.03 ± 0.182, respectively [Table 3]. Four (13%) patients required treatment for hypotension. Three (10%) patients complained of nausea and vomiting. Ten (33.3%) patients complained of shivering [Table 4]. There were no episodes of bradycardia in any of the patients. There was no other major complication associated with epidural catheter placement. There were no episodes of airway compromise or dural puncture.

Figure 1.

CORSORT flowchart

Table 1.

Demographic data

Variables	Mean±SD
Age (years)	55.17±13.628
Height (cm)	153±6.274
Weight (kg)	61.07±12.195

SD=Standard deviation

Table 2.

Surgical and anesthesia parameters

Variable	Mean±SD
Mean duration of surgery (min)	143.28±14.897
Mean time from epidural bolus to skin incision (min)	17.86±2.574
Local infiltration (mL)	6.90±4.515
Total IV propofol (mg)	18.97±11.880

SD=Standard deviation, IV=Intravenous

Table 3.

Postoperative pain and satisfaction score

	Mean±SD
Postoperative time (min)
1 h	1.31±0.660
4 h	1.45±1.021
12 h	1.31±1.004
Satisfaction score
Surgeon	9.14±0.163
Patient	9.03±0.182

SD=Standard deviation

Table 4.

Complication

Variable	n (%)
Bradycardia	0
Hypotension	4 (13)
Nausea/vomiting	3 (10)
Respiratory depression	0

DISCUSSION

This study shows that opioid-free anesthesia and postoperative analgesia for breast cancer surgeries are feasible with thoracic epidural anesthesia. Although controversial, there is increasing evidence that opioid-free regional anesthetic techniques could decrease the degree of metastasis in breast cancer surgeries.[4,5] In this study, we could avoid the use of opioids completely in both intraoperative and postoperative period in all our patients.

Breast cancer surgeries are commonly performed under general anesthesia. Improper management of pain in breast cancer surgeries can lead to the development of postmastectomy pain syndrome.[6,7] Usually, opioids are used to manage pain. Animal studies have shown that opioids have immunosuppressive effects.[8,9,10] Recent studies have shown an association between increased doses of opioids and cancer recurrence.[11] Enhanced recovery after surgery protocols advocate opioid-free anesthesia to enable early ambulation and return of bowel motility.[12] Opioid-free anesthesia of breast surgeries have been reported by supplementing general anesthesia with ultrasound guided erector spinae block or by use of sole paravertebral blocks.[13]

Regional anesthesia reduces surgery-induced neuroendocrine stress response, thereby reducing opioid requirement and incidence of cancer recurrence.[14,15] Neuraxial blocks along with general anesthesia have been used for providing postoperative analgesia. In a study by Santonastaso et al., paravertebral block was used to provide opioid-free anesthesia for breast cancer surgeries.[16] For performing successful blocks, skilled anesthetist and ultrasound facilities are required.[2]

There are reports of thoracic paravertebral blocks being used as a sole anesthetic to perform breast surgeries. However, they are associated with complications like accidental pneumothorax and vascular puncture. Cervical epidural techniques were successfully used for performing breast surgeries.[17] However, placing cervical epidurals are difficult and expertise to perform cervical epidural may be restricted to few teaching or tertiary care centers. There are few case reports of successful use of thoracic epidural for mastectomy in high risk patients.[18,19,20]

In this study, we have used thoracic epidural anesthesia which most of the anesthetists are regularly performing for upper gastrointestinal surgeries. Thoracic epidural anesthesia could be blindly performed and could be used as a sole anesthetic for breast cancer surgery. The epidural space in the thoracic region is wider compared to cervical region providing better safety. We could successfully place epidural in all our patients and none of the patients required conversion to general anesthesia.

Yang et al. in their study found that lignocaine and ropivacaine could inhibit the growth, invasion, and migration of cancer cells by activating the mitogen-activated protein kinase, caspases Bcl-2, and the intrinsic mitochondrial apoptosis pathway.[21] Intravenous use of lignocaine and was found to exert a protective effect on cell-mediated immunity and inhibit tumor recurrence.[22] Propofol is also believed to have antitumor property.[5] Hence, we used propofol for sedation and lignocaine and ropivacaine as local anesthetic.

We did not observe any major complications, and nausea and hypotension were encountered in some patients. Hypotension was easily managed with fluid boluses and ephedrine. There was no incidence of bradycardia, respiratory depression, accidental dural puncture, postdural puncture headache, or any neurological complications. Axillary sparing was encountered due to innervations by lower cervical roots. However, this could be managed with local infiltration of the area and sedation with intravenous propofol. Even though we encountered hypotension, we could easily manage it with 250 mL of fluid bolus and ephedrine boluses. None of the patients required ionotropic support. Shivering was seen frequently and was managed with forced air warmer. We did not encounter pruritus as we had not used opioids. Postoperative analgesia was maintained with epidural and none had pain score above three.

Our study has many limitations. The number of patients studied was too small to reliably assess safety. A larger sample size could have given a better perspective of thoracic epidural in patients undergoing breast surgery. A single consultant anesthesiologist had performed all the thoracic epidurals and the study is from a single institution. Future trials to compare thoracic epidural with other regional blocks for performing opioid-free surgeries for breast cancer should be undertaken.

CONCLUSIONS

Based on our data, it appears to be safe to perform opioid-free breast cancer surgeries under thoracic epidural anesthesia with complimentary sedation and local infiltration. Epidural infusion of local anesthetic provides excellent intra- and postoperative analgesia which helps avoid the use of opioids.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.