The Clinical Impact of Pectoral Nerve Block in an ‘Enhanced Recovery After Surgery’ Program in Breast Surgery

Abstract

Background: Pectoral nerve block (PECS) is increasingly performed in breast surgery. Aim: The study evaluated the clinical impact of these blocks in the postoperative course. Patients & methods: In this case–control study, patients undergoing breast surgery with ‘enhanced recovery after surgery’ pathways were divided into group 1 (57 patients) in whom PECS was performed before general anesthesia, and group 2 (57 patients) in whom only general anesthesia was effected. Results: Postoperative opioid consumption (p < 0.002), pain at 32 h after surgery (p < 0.005) and the length of stay (p < 0.003) were significantly lower in group 1. Conclusion: Reducing opioid consumption and pain after surgery, PECS could favor a faster recovery with a reduction in length of stay, ensuring a higher turnover of patients undergoing breast surgery.

Plain language summary

‘Enhanced recovery after surgery’ (ERAS) protocols have been recently applied in breast cancer patients in order to improve the postoperative course. However, the incidence of moderate to severe pain after breast surgery is frequent, and a multimodal approach is recommended. In this view, the interfascial plane blocks are advocated as a valid alternative to both paravertebral and epidural blockade. In this study, we evaluated the effects of these blocks on the postoperative course in patients undergoing breast surgery with ERAS protocols. We compared two patient groups: in the first, pectoral blocks were performed before general anesthesia, while in the second no block was carried out. We found that in the patient group receiving the blocks, postoperative opioid consumption (with essentially the same pain after surgery) and length of stay were significantly lower. Therefore, although more robust studies are needed to confirm our findings, these emerging locoregional techniques could favor a faster recovery in the context of ERAS in breast surgery. These results could have important clinical implications in terms of not only reducing healthcare costs but also ensuring a higher turnover of patients undergoing breast surgery.

Keywords::

• breast analgesia
• breast surgery
• ERAS
• length of stay
• opiod-sparing analgesia
• PECS block
• post-operative opioid consumption
• postoperative pain

Enhanced recovery after surgery (ERAS) programs are spreading in many surgical specialties and are aimed at improving the standard of perioperative care, with the aim of reducing the loss of functional capacity and consequently favoring a faster recovery process. ERAS protocols have shown significant benefit in major abdominal surgery and today are applied also to other specialties such as breast surgery [1,2]. The ERAS breast surgery implementation focuses on some fundamental items such as fluid management tending toward near-zero balance, prompt mobilization after surgery, an early postoperative feeding and multimodal perioperative pain treatment in order to favor an opioid-sparing strategy [3]. Breast surgery is associated with a significant incidence of moderate-to-severe postoperative pain, which can reach up to 60% based on the complexity of the surgery [4,5]. Actual guidelines on postoperative pain management in breast cancer surgery emphasize the importance of a multimodal opioid-sparing approach [5]. This involves the systematic use of acetaminophen, NSAIDs or selective COX2 inhibitors, steroids such as dexamethasone and locoregional techniques [6]. Recently, interfascial plane blocks as a practicable alternative to both paravertebral and epidural blockade in the management of postoperative pain after breast surgery have been advocated [6]. Indeed, pectoral nerve block type I (PECS I block) and type II (PECS II block) have been found to be effective in terms of postoperative analgesia and lower opioid consumption in patients undergoing breast surgery [7,8]. However, although current literature describes the benefit of these blocks, it still remains to be clarified whether the use of these techniques can improve the postoperative course.

The aim of this study is to evaluate the clinical impact of PECS blocks in patients undergoing ERAS breast surgery in terms of reduction of the length of stay (LOS), opioid consumption and postoperative pain compared with the sole use of systemic multimodal analgesia.

Materials & methods

Enhanced recovery after surgery protocol

All study patients adhered to the ERAS breast program, first launched at our institution in January 2019. Our ERAS protocol included several core tenets: preoperative counseling, perioperative pain adjuncts with multimodal analgesia to limit postoperative oral narcotics, limited perioperative fluid administration, the usage of two or three antiemetic drugs (5-HT3 receptor antagonists, corticosteroids, butyrophenones), based on overall risk as guided by the Apfel score [9] for multimodal postoperative nausea and vomiting (PONV) prophylaxis. The ERAS protocol provides early mobilization and clear liquids intake as soon as possible in the postoperative period. Furthermore, on day 0, patients are encouraged to walk from bed to chair and to eat a light meal. The discharge criteria were as follows: adequate oral nutrition, adequate pain control with analgesics administered orally, motor autonomy and personal hygiene care, no clinical and/or laboratory evidence of postoperative complications, agreement by the patient.

Study design

The authors certify that their research is in accordance with ethical standards of the Helsinki Declaration. In addition, informed consent has been obtained from the participants involved. The case–control study was conducted in our institution, a community general hospital in Florence, Italy. All female patients who underwent breast cancer surgery with the ERAS program between January 2019 and March 2022 were considered. The patients were divided into two groups: group 1, composed of patients who received PECS block before the induction of general anesthesia between January 2021 and January 2022; group 2 (control), in which patients did not receive locoregional analgesia techniques before general anesthesia between January 2019 and January 2021. We decided to enroll the matching control group using a 1:1 scheme. For each patient of group 1, one control patient matched for gender, American Society of Anesthesia Physical Status (ASA-PS) score, type of surgery and age (using a ± 5 years criterion) was selected. The following exclusion criteria were considered: incomplete clinical data (e.g., age, type of intervention, ASA-PS score, drugs administered, clinical parameters every 6 h postoperatively), or breast reconstructive and urgent surgery. Particularly, patients with a long history of opioid or NSAID use, neurological deficits or a history of mental illness were excluded from the study. During the enrollment of the control group, quadrantectomy with or without axillary dissection and simple mastectomy with or without axillary dissection were considered respectively comparable. During the study period, the PECS and parasternal block were performed in accordance with the original technique blocks, using a B Braun Stimuplex^® Ultra 360^®, 80 mm, 22G 30° needle and Mindray M6 with linear probe L14-6Ns echography (Mindray, Shenzhen, China) [10,11].

The choice of the type of block was made according to surgery. Specifically, PECS block II was used in outer (upper and lower) quadrantectomy with sentinel lymph node evaluation. In inner quadrant (upper and lower) quadrantectomy with sentinel lymph node evaluation and mastectomies with or without axillary dissection, PECS II and parasternal blocks were performed. In all patients, intraoperative acetaminophen 1 g and ketorolac 30 mg were administered. During the study period, the choice of anesthesia technique (total intravenous anesthesia [TIVA] or balanced) was decided by the anesthesiologist on the day of surgery. Entropy analysis on electroencephalography signal and surgical pleth index were applied before induction. Balanced anesthesia was induced by administration of propofol (2 mg/kg). Desflurane and remifentanil were also used for induction before the laryngeal mask positioning. Remifentanil was administered via target-controlled infusion in all patients enrolled. Anesthesia was maintained with desflurane 5–6% in 50% oxygen and 2–2.5 ng/ml of effect-site remifentanil concentration. In TIVA, instead of desfluorane, a propofol infusion with target concentrations of 2.5–4.0 μg/ml was used.

Pain was assessed at 8, 16, 24, 32, 40 and 48 h postoperatively using a numeric rating scale, in which 0 indicates no pain and 10 corresponds to the worst pain imaginable [12]. In all patients, acetaminophen (1 g three times a day) and ibuprofen (400 mg twice a day) after surgery were scheduled. Opioid drugs were administered at patient request or when pain score >3.

The following adverse events were considered: PONV; postoperative bleeding (hematoma) with or without need for blood transfusions; new-onset arrhythmias requiring treatment; severe acute respiratory failure; non-severe acute respiratory failure (requiring drug treatment but no ventilatory support); postoperative desaturation (SpO₂ 90% requiring oxygen therapy only); occurrence of pneumothorax.

The possible influence of these blocks on the LOS was considered the primary outcome; postoperative pain, opioid consumption and the incidence of adverse events were also evaluated as secondary outcomes.

Data collection & statistical analysis

A prospective database was structured and updated by the anesthesiology team using the electronic medical record of the hospital program. This program includes information on the clinical course (clinical parameters, specialist consultations, nursing activities), daily specialist visits and data relating to the outcome measures. Furthermore, in the hospital program, scheduled and administered drugs (e.g., opioids) were also identified from the local database updated by a surgeon, a nurse and an anesthesiologist of the working team.

Preoperative demographic characteristics including age, gender, ASA-PS score and type of surgery were collected from the anesthesiology team.

Data are expressed as mean ± standard deviation for parametric variables and number (percentage) for categorical variables. Comparison between the two groups was performed using Student’s t-test for parametric variables and Pearson’s χ-square test or Fisher’s exact test when appropriate for categorical variables; p < 0.05 was considered for statistical significance. All analyses were performed using SPSS v. 15.0 (SPSS, Inc., IL, USA).

Results

Among a total of 141 patients considered, 27 patients were excluded (15 for not meeting criteria, 10 for PECS block refusal and 2 others). Therefore, 114 patients were included in the study, 57 for each study group. No differences in the demographic and clinical data of the excluded patients were identified. The data relating to the descriptive characteristics, the type of anesthesia and surgery are shown in Table 1. No differences were observed in the type of surgery and tumor location in the quadrant surgery (p = 0.98). For each group, three patients (5.2%) were classified as ASA-PS 1, 42 (73.7%) as ASA-PS 2, 11 (19.3%) as ASA-PS 3 and one (1.8%) as ASA-PS 4. Data relating to postoperative pain, opioid consumption, LOS and adverse events are reported in Table 2.

Table 1. Descriptive characteristics of the two study groups.

	Group 1 (n = 57)	Group 2 (n = 57)	p-value
Age (years), mean (SD)	65.3 ± 14.7	63.1 ± 13.7	0.41
BMI (kg/m^2), mean (SD)	22.8 ± 2.8	23.9 ± 3.1
Surgical time (min), mean (SD)	65.80 ± 20.93	67.53 ± 19.61	0.27
Type of anesthesia			0.32
– Balanced, n (%)	26 (45.6)	23 (40.4)
– TIVA, n (%)	31 (54.4)	34 (59.6)
Type of surgery			0.97
Mastectomies with axillary dissection, n (%)	21 (36.8)	20 (35.0)
Mastectomies, n (%)	6 (10.5)	7 (12.3)
Quadrantectomies with axillary dissection, n (%)	22 (38.6)	23 (40.3)
Quadrantectomies + LS, n (%)	8 (14.1)	7 (12.2)
Tumor location in quadrantectomies			0.98
UOQ/LOQ, n (%)	11 (36.6) / 8 (26.7)	12 (40.) / 8 (26.7)
UIQ/LIQ, n (%)	5 (16.7) / 6 (20)	4 (13.3) / 6 (20)

LIQ: Lower inner quadrant; LOQ: Lower outer quadrant; LS: Sentinel lymph node; SD: Standard deviation; TIVA: Total intravenous anesthesia; UIQ: Upper inner quadrant; UOQ: Upper outer quadrant.

Table 2. Postoperative data.

Timepoint	NRS values (%)	Group 1 (n = 57)	Group 2 (n = 57)	p-value
At 8 h	0	75.00	70.18	0.7
	1	17.88	17.54
	2	5.35	7.02
	3	0	3.51
	4	1.77	1.75
At 16 h	0	50.94	62.50	0.49
	1	28.30	16.07
	2	18.87	17.85
	3	1.89	1.79
	4	0	1.79
At 24 h	0	67.35	66.17	0.63
	1	22.45	27.20
	2	8.16	4.53
	3	2.04	2.10
	4	0	0
At 32 h	0	47.82	78.26	0.038
	1	34.78	15.22
	2	15.22	4.35
	3	2.18	2.17
	4	0	0
At 40 h	0	69.23	68.18	0.99
	1	23.08	22.72
	2	7.69	9.10
	3	0	0
	4	0	0
At 48 h	0	54.29	61.11	0.17
	1	40.00	16.67
	2	5.71	11.10
	3	0	5.56
	4	0	5.56
Opioids consumption (mg)		5 ± 0.1^†	17 ± 0.2^†	0.002
LOS (days)		1.2 ± 1^†	1.6 ± 1.1^†	0.03
LOS (h)		31.7 ± 22.5^†	41.8 ± 25.6^†	0.03
Adverse events (n)		3 ± 0.05^†	2 ± 0.03^†	0.65

† Data are expressed as median and standard deviation; NRS values are expressed as percentages calculated in patients with available data according to LOS.

LOS: Length of stay; NRS: Numeric rating scale.

Group 1 had a significant reduction in LOS (p = 0.003) when compared with the control group. In addition, the same group experienced a reduction in opioid consumption in comparison with the control group (p < 0.002). Among group 1, five patients used opioids: three patients 10 mg oxycodone, one patient morphine 2 mg and another tramadol 100 mg. Opioid use occurred in 17 patients of group 2: specifically, in five patients oxycodone 10 mg, in ten patients codeine (for an average overall dosage of 60 mg), in one patient tramadol 100 mg and in another tapentadol (for a total dosage of 100 mg) were administered.

In group 1, one patient developed a pneumothorax, which resolved after 5 days, and was discharged after 8 days. In the control group, in two patients a postoperative pneumonia was diagnosed. No bleeding events occurred.

Discussion

The study showed that the use of interfascial plane blocks (PECS block) is associated with a reduction in LOS, pain reduction and lower postoperative opioid consumption when compared with systemic multimodal analgesia alone in an ERAS breast surgery program.

To our knowledge, the shorter LOS in patients undergoing ERAS breast surgery where PECS blocks were performed represents a new finding compared with the current literature [13]. Recently, in a retrospective cohort study, Diana et al. [14] showed similar results, although the relative reduction of mean opioid consumption in the PECS group (3 mg) was lower than in our study (12 mg). Nonsignificant pain score after surgery and PONV were also registered in both studies. Furthermore, in the same study a lower LOS was found in the PECS group (2.5 vs 3 days), leading the authors to hypothesize that the technique may allow day surgery in a selected group of patients undergoing mastectomy. Similarly, although our results showed an overall lower LOS in the sample, the reduction of LOS (1.2 vs 1.6 days) in the PECS group could effectively enhance discharge of all patients within 24 h after surgery. Although both study groups observed low pain score after surgery, this locoregional technique – which is also characterized by a low incidence of adverse events – may favor a safe day-surgery program, ensuring a low level of pain even after 24 h and safer pain management after hospital discharge. A shorter LOS could have several clinical implications in terms of not only reducing healthcare costs but also ensuring a higher turnover of patients undergoing breast surgery, which is mandatory for all time-consuming neoplastic diseases. Although postoperative pain in the PECS group was significantly low at 32 h after surgery, the study showed a substantially low level of pain in both study groups. However, the clinical impact of these data can be underestimated if the number of patients to whom opioids were administered in both groups is not taken into account. Indeed, the execution of the PECS block almost completely avoided the use of opioid drugs in the postoperative period: only 5/57 (8.7%) patients needed opioids as a rescue dose after surgery. However, evidence about reduction of the pain score after PECS block is conflicting. Although only a retrospective control study considered the application of this locoregional technique in the context of ERAS breast surgery, some studies showed a lower postoperative pain than in the control group [15,16]; conversely, our data are similar to the results other studies where this issue was not significant [14,17,18].

As regards the opioid-sparing effect, Grape et al. demonstrated how the use of PECS block is able to determine a reduction in pain, both at rest and with effort, and a decrease in opioid consumption and incidence of PONV in the first 24 h postoperatively [19]. Moreover, the effectiveness of these locoregional techniques is equivalent in unilateral and bilateral radical mastectomy, as in other types of breast surgery [20]. In our study, the important reduction of the opioids administration after surgery may have favored both the early oral fluid and food intake and an adequate motor autonomy, making possible an earlier discharge. In this regard, the opioid-sparing effect related to these techniques may have had a crucial role in promoting adherence to the postoperative core tenets [20,21].

Unlike recent literature, in this study a reduction in the incidence of PONV was not observed. However, the incidence was very low in both study groups (group 1: 3%; group 2: 5%; p = not significant). It is conceivable that the perioperative administration of two or three prophylactic antiemetics to all patients could have substantially reduced the incidence of this adverse event. This prophylactic approach may have ensured a low incidence of PONV in the two study groups – also considering the anesthetic technique performed (TIVA or balanced anesthesia) – although halogenated anesthetics represent a known risk factor for PONV [22].

The low incidence of adverse events in the two study groups confirms the safety of PECS blocks, which have a relatively short learning curve. Indeed, only in one patient of group 1 did the execution of the interfascial plane blocks cause the appearance of pneumothorax. It should be highlighted that this was related to an implementation period of these blocks [23]. Furthermore, the resulting increase in the days of hospitalization had no significant effect on the overall duration in the group 1.

This study has several limitations: the retrospective analysis and the method of patient enrollment, typical of a case–control study, should be considered. Furthermore, the single-center nature of the study does not allow us to draw a definitive conclusion about the existence of a relationship between PECS blocks and lower LOS. Moreover, no data are available about the intraoperative opioid consumption in the study groups. Lastly, it should be considered that current literature shows that ERAS programs are mostly effective for breast reconstruction and mastectomy with or without axillary dissection [24,25]. In this study, the application of the perioperative core tenets was extended also to quadrantectomies.

Conclusion

Although a consolidation of the results through prospective and randomized studies is required, this study highlights that the reduction in LOS with the use of PECS blocks in ERAS breast surgery may favor a day-surgery program. These facts could have clinical implications by favoring a higher turnover of patients in the breast unit, which is crucial in this time-consuming neoplastic disease. Furthermore, these techniques are associated with a low incidence of adverse events, ensuring adequate pain control and lower opioid consumption in the postoperative period.

Summary points

• The use of regional anesthesia is essential in enhanced recovery after breast surgery programs.

• Pectoral nerve block (PECS) is advocated as a valid choice in order to assure a multimodal approach to perioperative pain treatment.

• PECS blocks are a locoregional technique with an opioid-sparing effect and low incidence of adverse events.

• PECS blocks may favor a reduction in length of stay.

• Although evidence is conflicting, PECS blocks could be effective in postoperative pain control.

• The use of regional anesthesia, with PECS, may ensure a higher turnover of patients undergoing breast surgery.

• PECS blocks could change clinical practice and favor a day-surgery approach to breast surgery.

Author contributions

D Conti, J Valoriani and V Pavoni participated in the design of the study. M Pazzi, L Gianesello, V Mengoni, V Criscenti, E Gemmi, C Stera, F Zoppi and L Galli participated in the data acquisition. P Ballo performed the statistical analysis and interpretation of data. D Conti wrote the first draft version of the manuscript. V Pavoni critically revised the manuscript for important intellectual content. All authors read and approved the final version of the manuscript.

Competing interests disclosure

The authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, stock ownership or options and expert testimony.

Writing disclosure

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Financial disclosure

The authors have no financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.