Study reference

(first author, publication year)

Was the allocation sequence adequately generated?

Definitely yes

Probably yes

Probably no

Definitely no

Was the allocation adequately concealed?

Definitely yes

Probably yes

Probably no

Definitely no

Blinding: Was knowledge of the allocated

interventions adequately prevented?

Were patients blinded?

Were healthcare providers blinded?

Were data collectors blinded?

Were outcome assessors blinded?

Were data analysts blinded?

Definitely yes

Probably yes

Probably no

Definitely no

Was loss to follow-up (missing outcome data) infrequent?

Definitely yes

Probably yes

Probably no

Definitely no

Are reports of the study free of selective outcome reporting?

Definitely yes

Probably yes

Probably no

Definitely no

Was the study apparently free of other problems that could put it at a risk of bias?

Definitely yes

Probably yes

Probably no

Definitely no

Overall risk of bias

If applicable/necessary, per outcome measure

LOW

Some concerns

HIGH

Comparison 1: SAP versus PV

Arora, 2022

Probably yes;

Reason: Randomization with computer generated random numbers, but method not further specified.

Probably yes;

Reason: Opaque, sealed envelopes were used. However, it is not described how/ by whom they were opened.

Probably no;

Reason: Patients and health care providers (anesthesiologist) not blinded. Outcome assessors and data collectors blinded. Blinding of analysts not reported.

Probably no;

Reason: loss to follow-up was not described, but it was reported that one patient in the SAPB group had no sensory deficit and was considered as block failure.

Definitely yes

Reason: All relevant outcomes were reported.

Probably no;

Reason: it is not clear how patients were recruited and how many of eligible patients were excluded based on the exclusion criteria.

Some concerns

Allocation, blinding and unclear recruitment and selection of patients.

Gabriel, 2021

Probably yes;

Reason: Randomization using a computer-generated list, but method not further specified..

Probably yes;

Reason: Opaque, sealed envelopes were used. However, it is not described how/ by whom they were opened.

Probably no;

Reason: Patients, health care providers (anesthesia team) and outcome assessors (nurses) blinded. Blinding of data collectors and analysts not reported.

Definitely no;

Reason: is was reported that there was no loss to follow-up, and that no patients were excluded from the analysis.

Definitely yes;

Reason: All relevant outcomes were reported.

Definitely yes;

Reason: No other problems noted.

Some concerns

Jain, 2020

Probably no;

Reason: only reported that there was random allocation but not the method.

Probably yes;

Reason: Opaque, sealed envelopes were used. It is not described how/by whom they were opened.

Definitely no;

Reason: non-blinded RCT.

Definitely no;

Reason: is was reported that there was no loss to follow-up, and that no patients were excluded from analysis.

Definitely no;

Reason: data on postoperative pain were only limited presented in the text.

Definitely yes;

Reason: No other problems noted

HIGH

Unclear allocation, non-blinded RCT, data on postoperative pain limited presented.

Amin, 2018

Probably yes;

Reason: Randomization with computer generated random numbers, but method not further specified.

Probably yes;

Reason: sealed envelopes were used, but it is not described how/ by whom they were opened.

Probably no;

Reason: single-blinded. Patients were blinded and health care providers were not blinded (different procedures for the groups were described). Blinding of data collectors, outcome assessors and analysts not reported.

Probably no;

Reason: loss to follow-up was not described, but results on outcome measures are available for the included samples (n=60; I=30, C=30)

Definitely yes;

Reason: All relevant outcomes were reported

Probably no;

Reason: it is not clear how patients were recruited and how many of eligible patients were excluded based on the exclusion criteria.

Some concerns

Single-blinded (patients) RCT, unclear patient recruitment.

Gupta, 2017

Probably yes;

Reason: Randomization with computer generated random numbers, but method not further specified.

Probably yes;

Reason: sealed envelopes were used, but it is not described how/by whom they were opened.

Probably yes;

Reason: double-blinded, patients and health care providers were blinded. Blinding of data collectors, outcome assessors and analysts not reported.

Definitely no;

Reason: is was reported that there was no loss to follow-up, and that no patients were excluded from analysis.

Probably no;

Reason: Results on post-operative pain (mean visual analogue scales) only presented in a figure, without SD/ CI in numbers.

Definitely yes;

Reason: No other problems noted

Some concerns

Outcome postoperative pain

Comparison 3:  ESP versus SAP

Jiang, 2020

Definitely yes;

Reason: Randomization with computer generated random numbers, created by an independent researcher.

Probably no;

Reason: not described

Probably yes;

Reason: health care providers and data collectors blinded (blinding of patients, outcome assessors and analysts not reported)

Definitely yes;

Reason: There was no loss to follow-up in intervention and control group.

Probably no;

Reason: Results provided in figures, no absolute values available for postoperative pain

Definitely yes;

Reason: No other problems noted

Some concerns

Method of allocation unclear, limited reporting of outcome postoperative pain

Shrivastava,  2021

Probably yes;

Reason: Randomization with computer generated random numbers, but method not further specified.

Probably no;

Reason: not described

Probably no;

Reason: not described

Probably yes;

Reason: no loss to follow-up in intervention and control group, but N not described in tables

Probably no;

Reason: Results postoperative pain provided without standard deviations

Definitely yes;

Reason: No other problems noted

HIGH

Method of allocation unclear, blinding unclear, limited reporting of outcome postoperative pain

Comparison 4:  PECS II versus PV

Jain, 2020

Probably no;

Reason: only reported that there was random allocation but not the method.

Probably yes;

Reason: Opaque, sealed envelopes were used. It is not described how/ by whom they were opened.

“Allocation concealment was done by sequentially numbered, opaque, sealed envelopes.”

Definitely no;

Reason: non-blinded RCT

Definitely no;

Reason: is was reported that there was no loss to follow-up, and that no patients were excluded from analysis.

Definitely no;

Reason: data on postoperative pain were only limited presented in the text.

Definitely yes;

Reason: No other problems noted

HIGH

Unclear allocation, non-blinded RC, data on postoperative pain limited presented

Comparison 5:  PECS II versus SAP

Bakeer, 2020

Probably yes;

Reason: Central randomization with computer generated random numbers, but method not further specified.

Probably yes;

Reason: Opaque, sealed envelopes were used. It is not described how/ by whom they were opened.

Probably yes;

Reason: Patients, health care providers and data collectors blinded (blinding of Patients, outcome assessors and analysts not reported).

Probably yes;

Reason: Loss to follow-up was infrequent in intervention and control group.

Definitely yes;

Reason: All relevant outcomes were reported.

Definitely yes;

Reason: No other problems noted.

Some concerns

Jain, 2020

Probably no;

Reason: only reported that there was random allocation but not the method

Probably yes;

Reason: Opaque, sealed envelopes were used. It is not described how they were opened.

“Allocation concealment was done by sequentially numbered, opaque, sealed envelopes.”

Definitely no;

Reason: non-blinded RCT

Definitely no;

Reason: is was reported that there was no loss to follow-up, and that no patients were excluded from analysis

Definitely no;

Reason: data on postoperative pain were only limited presented in the text

Definitely yes;

Reason: No other problems noted

HIGH

Unclear allocation, non-blinded RCT

Data on postoperative pain limited presented

Fujii, 2019

Definitely yes;

Reason: Randomization with computer generated random numbers, but method not further specified.

Probably no;

Reason: not described

Probably yes;

Reason: Patients, health care providers and data collectors blinded (blinding of Patients, outcome assessors and analysts not reported).

Definately yes;

Reason: Loss to follow-up was infrequent in intervention and control group.

Definitely yes

Reason: All relevant outcomes were reported;

Definitely yes;

Reason: No other problems noted

Some concerns

Method of allocation unclear

Comparison 2: ESP versus PV

Xiong, 2021

Yes

Yes

Yes

Yes

N/A

Yes, all included studies had high risk of bias

Yes

Yes, not detected

Unclear

Not specified for included studies

Comparison 3: PECS II versus ESP

Elshanbary, 2021

Yes

Yes

Yes

No, information on measurement method of outcomes is lacking

N/A

Yes, included studies had moderate to low risk of bias

Yes

Yes

Unclear

Not specified for included studies

Comparison 4: PECS II versus PV

Elshanbary, 2021

Yes

Yes

Yes

No, information on measurement method of outcomes is lacking

N/A

Yes, included studies had moderate to low risk of bias

Yes

Yes

Unclear

Not specified for included studies

Study reference

Study characteristics

Patient characteristics ²

Intervention (I)

Comparison / control (C) ³

Follow-up

Outcome measures and effect size ⁴

Comments

Comparison 1: SAP versus PV

Arora (2022)

Study design:

RCT

Setting and country:
Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh, India

Funding and conflicts of interest:

Funding: not reported

Conflict: reported that the authors declare no conflicts of interest.

Inclusion criteria:

(1)ASA (American Society of Anesthesiologists) physical status I---II female patients (2)age group of 18-65 years, (3) scheduled to undergo total mastectomy (4) with axillary clearance (5) under general anesthesia

Exclusion criteria:

The patients who had (1) local infection at the block site, (2) coagulopathy, (3) morbid obesity (BMI > 40 kg.m-2), (4) allergy to local anesthetics, (5) decreased pulmonary reserve, (6) uncontrolled hypertension or ischemic heart disease, (7) renal dysfunction, and (8) pre-existing neurological deficits and psychiatric illness were excluded.

N total at baseline:

I: 20

C: 20

Important prognostic factors²:

age (years) mean ± SD

I: 50.8 ± 9.5

C: 48.2 ± 9.8

ASA I:II (n)

I: 15:5

C: 16:4

Groups comparable at baseline?

The groups were comparable regarding the patients’ age, weight, height, and ASA physical status. Although more patients in the SAPB group had sensory spread at the level of T1, T2, and T6 as compared to the TPVB group, it was not statistically significant.

SAP

3-5 ml lignocaine 2%; 0.4 mL.kg-1 ropivacaine 0.5%

PV

3-5 ml lignocaine 2%; 0.4 mL.kg-1 ropivacaine 0.5%

Length of follow-up:

24 hours after surgery in the postanesthesia care room

Loss-to-follow-up:

No loss to follow up

Incomplete outcome data:

1 patient in the SAP group had no sensory deficit and considered as block failure.

Postoperative pain*

NRS

“Post-operative pain scores were significantly lower in the SAPB group as compared to the TPVB group (p < 0.05) during the first 2 hours and then at 6, 8, and 24 hours after surgery”

p-values:

½ h < 0.001

1 h = 0.007

6 h = 0.040

12 h = 0.080

24 h = 0.032

Adverse events

No block- related adverse effects were reported in any group of patients.

Study aim: to compare the efficacy of SAPB with the thoracic paravertebral block (TPVB) for postoperative analgesia after breast cancer surgery.

*results presented in figure without mean-values

**Patients with NRS more than 3 or those demanding analgesics received diclofenac sodium 75 mg intravenously. If NRS was remained high 30 minutes after administration of diclofenac, then injection tramadol 1 mg.kg-1 was given.

Author conclusion: The SAPB group patients also showed lower postoperative pain scores and demanded less rescue analgesia in comparison to the TPVB group. The postoperative tramadol consumption was low in both groups.

In conclusion, we found SAPB superior to TPVB in terms of prolonged duration of postoperative analgesia and reduced rescue analgesic requirement after radical mastectomy in breast cancer patients. Therefore, SAPB may be a viable alternative to the TPVB, which is technically more challenging and have a higher potential for adverse effects. Further studies are required to compare the efficacy and safety of SAPB with other chest wall blocks. As SAPB usually provides 4-6 hours of postoperative analgesia in these patients, the role of additives can also be assessed.

Gabriel (2021)

Study design:

RCT (randomized, subject-masked, parallel-arm, active-controlled study)

Setting and country: University of California San Diego, La Jolla, California, USA

Funding and conflicts of interest: Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

Conflict: The University of California has received funding and product for other research projects from Epimed International (Farmers Branch, Texas, USA); Infutronics (Natick, Massachusetts, USA); and SPR Therapeutics (Cleveland, Ohio, USA) for the following authors: RG, MWS, JFS, ETS, BK, JJF, AMW and BMI. RG is a consultant for Avanos (Alpharetta, Georgia, USA).

Inclusion criteria: (1) Adults (≥ 18 years) (2) unilateral or bilateral breast surgery (3) moderate postoperative pain anticipated (4) a planned single-injection regional analgesic

(including lumpectomy with axillary node biopsy/resection, breast reconstruction, breast reduction, mastopexy, and implant expander removal/placem)

Exclusion criteria:

(1) simple lumpectomy (with no other procedure), (2) planned regional analgesic with perineural catheter placement, (3) morbid obesity as defined as a body mass index >40 kg/m2 , (4) renal insufficiency (preoperative creatinine >1.5 mg/ dL), (5) current chronic opioid use (daily equivalent of >30 mg of morphine within the 2 weeks prior to surgery and duration of use >4 weeks), (5) history of opioid abuse, (6) any comorbidity that results in moderate or severe functional limitation, (7) inability to communicate with the investigators or hospital staff, (8) pregnancy, (9) incarceration and allergy to study medications (ropivacaine) (10) Patients undergoing mastectomy were excluded since they are offered a continuous PVB at the institution as standard care.

N total at baseline:

I: 49

C: 51

Important prognostic factors²:

age (years) median (IQR)

I: 55.0 (44.0–64.0)

C: 53.0 (41.5–61.5)

Female sex n (%)

I: 49 (100%)

C: 48 (94.1%)

Bilateral procedure n (%)

I: 17 (34.7%)

C: 19 (38.0%)

Groups comparable at baseline? Yes, no imbalances in baseline characteristics

SAP

Local anesthetic (0.5% ropivacaine) with 1:400 000 of epinephrine was deposited deep to the serratus anterior muscle (20 mL for unilateral surgery, 16 mL on each side for bilateral surgery)

PV

Local anesthetic (0.5% ropivacaine) with 1:400 000 of epinephrine was injected at the appropriate level(s) after negative aspiration (20 mL for unilateral surgery, 16 mL on each side for bilateral surgery)

Length of follow-up:

1 day postoperatively (follow-up call)

Loss-to-follow-up:

No loss to follow-up in either group (POD1)

Incomplete outcome data:

No incomplete outcome data/ exclusion from analyses in either group

Postoperative pain

11-point NRS (0–10, 0=no pain, 10=worst pain imaginable)

Postoperative pain PACU

Median (IQR)

I: 4.0 (0–5.5)

C: 0 (0–3.0)
95% CI −3.00 to −0.00; p=0.001*

Postoperative pain morning POD1 (average) (+/-24h)

Median (IQR)

I: 3.0 (2.0–4.0)

C: 2.0 (0.5–3.0)
p<0.01

Opioid consumption***

intravenous morphine equivalents (MEQ) in mg = MME.

Opioid consumption morning POD1 (+/-24h)

Median (IQR)

I: 2.0 (2.0–4.0)

C: 2.0 (0–4.0)

p= 0.24

in mean ± SD:

I: 2 ± 0.33

C: 2 ± 1

Adverse events

There were no protocol deviations or adverse events related to the block procedures.

Study aim: to perform a randomized, subject-masked, parallel-arm, active-controlled study comparing PVB to serratus block for non-mastectomy breast surgery patients.

! Patients undergoing mastectomy were excluded since they are offered a continuous PVB at our institution as standard care.

* authors: The lower limit of the 95% CI was less than −1.25, which is lower than the prespecified framework for non-inferiority, and therefore, non-inferiority was not demonstrated. Note that the upper limit is less than 0–5 decimal places (−2.66×10−5), demonstrating inferiority.

** authors: In this case, the upper limit of the 95% CI was on the positive side of 0–6 decimal places (2.49×10−6). Since the 95% CI lower limit of −4.5 was less than our prespecified margin of −2.0, we failed to conclude that the serratus block is non-inferior to the PVB.

*** Opioid consumption was analyzed as intravenous morphine equivalents (MEQ). Intraoperative and postoperative intravenous fentanyl, intravenous hydromorphone, and oral oxycodone were converted to intravenous MEQ

Author discussion/conclusion: serratus blocks provided inferior analgesia compared with PVBs; and, regarding opioid requirements, we were unable to demonstrate at least non-inferiority of serratus blocks. Furthermore, there were several differences in our secondary outcomes favoring PVB, including need of antiemetics in the PACU, opioid consumption in the PACU, and worst/least NRS pain scores in the PACU and up to POD 1. Of note, all blocks were performed by fellowship-trained attendings or current fellows overseen by the attendings who all have a great deal of experience with both blocks. Thus, providers with less experience—especially with PVBs—may still elect to perform the less efficacious fascial plane block due to risk/benefit ratio concerns; while practitioners skilled at PVB have reason not to change their current practice for breast surgery.

This randomized active controlled study suggests that PVB provides improvements in short-term postoperative analgesia compared with serratus blocks following non-mastectomy breast surgery.

Jain (2020)

Study design:

RCT; prospective, randomized interventional nonblinded study

Setting and country: India Institute of Medical Sciences, New Delhi, India

Funding and conflicts of interest

Funding: Nil.

Conflict: reported that there are no conflicts of interest

Inclusion criteria: (1) ASA grades I and II (2) female patients  (3) aged 18–65 years (4) undergoing elective unilateral mastectomies with or without axillary dissection

Exclusion criteria: (1) Patients with infection at the site of proposed block, (2) chest wall deformity, (3) coagulopathy, or (4) receiving any anticoagulants, (5) body mass index ≥35 kg/m2 , (6) mental retardation were excluded from the study

N total at baseline:

I: 15

C: 15

Important prognostic factors²:

age (years) mean ± SD

I: 60.87±11.9

C: 44.47±11.62

ASA (I/II) n (%)

I: 11 (73.33)/4 (26.67)

C: 12 (80)/3 (20)

Groups comparable at baseline?

Yes, p-values demographic variables non-significant

USG SAP

0.375% ropivacaine

USG single injection PV

0.375% ropivacaine

Length of follow-up:

Not specifically reported, but it is stated that patient was kept in PACU for 24 h postoperative period and the outcomes measurements were performed up to 24h

Loss-to-follow-up:

Reported there was no loss to follow up

Incomplete outcome data:

I: SAP group: all received allocated intervention

C: TVPB group:  all received allocated intervention

Postoperative pain (VAS 0‑10) at rest and ipsilateral abduction of arm* with 0 corresponding to no pain and 10 being the worst imaginable pain.

“Pain scores were not significantly different among the group in the postoperative 24 h period. Only three patients gave a response at immediate postoperative and therefore VAS scores were not assessed at this point of time. At 6 h, VAS scores were reaching significant difference among PECS and SAP block.”

Opioid consumption: Postoperative fentanyl requirement in 24h in µg

(mean ± SD)[95%CI]

I: 415 ± 182.44 [95% CI 323–507]

C: 428.33 ± 243.1  [95% CI 308.33–548.33]

(IV morphine 10 mg = IV fentanyl 100 μg = IV sufentanil 10 μg)

In MME:

I: 41.5 ± 18.244 [95% CI 32.3–50.7]

C: 42.833 ± 24.31  [95% CI 30.833–54.833]

Adverse events

No complication like inadverdent vascular puncture, pneumothorax, hypotension was seen in any group.

Study aim: to compare the postoperative 24‑h fentanyl consumption in each of the three blocks. Secondary objectives were to compare spread of local anesthetic, sensory blockade produced, onset of the sensory blockade, intraoperative opioids requirement, pain scores for 24 h postoperative period, time to first postoperative analgesia requirement and incidence of postoperative nausea and vomiting (PONV).

* Pain scores (VAS 1‑10) were measured at rest and ipsilateral abduction of arm at 1, 2, 3, 6, 12, and 24‑hour postoperative.

à very limited results

Author conclusion: TPVB and SAP group provide equivalent analgesia in patients undergoing mastectomies. PECS II block is inferior to TPVB and SAP block in providing analgesia for breast surgeries. Single‑shot TPVB and SAP block also result in greater spread of the drug along with sensory block compared to PECS II block. SAP block is easier to perform than TPVB with lesser chances of complications and results in faster onset. Thus, we recommend SAP block for patients undergoing mastectomies for effective analgesia

Amin (2018)

Study design:

RCT (Prospective, single-blinded randomized study)

Setting and country:

Benha University Hospital, Egypt

Funding and conflicts of interest:

Funding: Nil.

Conflict: no conflicts or interest

Inclusion criteria: (1) Female patients (2) age of 30 and 60 years, (3) with cancer breast, (4) American Society of Anesthesia (ASA) I and II, (5) undergoing unilateral mastectomy operation

Exclusion criteria: (1) Refusal to participate, (2) morbid obesity (BMI >40 kg/m2 ),  (3) renal insufficiency (creatinine >1.5 mg/dl), (4)  current chronic analgesic therapy (daily use >4 weeks), (5) diabetes mellitus with polyneuritis, (6) generalized or local infection, (7) chronic pain in the anterolateral region of the chest or axilla, (8) inability to communicate with the medical staff and (9) ASA physical status III and IV

N total at baseline:

I: 30 

C: 30

Important prognostic factors²:

age (years) mean ± SD

I: 45±7

C: 42±8

ASA median (range)

I: 1 (1-2)

C: 1 (1-2)

Groups comparable at baseline?

Yes, no significant statistical difference as regards to age, weight, height, and ASA status, between both groups with a P value greater than 0.05.

US-guided SAP

0.4 ml/kg of bupivacaine 0.25% with 5 μg/ml epinephrine

US-guided PV

15–20 ml of 0.25% bupivacaine with 5 μg/ml epinephrine

Length of follow-up:

Not reported, but hospital stay length up to 3 days

Loss-to-follow-up:

Not reported

Incomplete outcome data:

Not reported

Postoperative pain at rest

VAS (0-10cm)

Median (range)

Postoperative pain at PACU

I: 1 (0-4)

C: 0 (0-4)

P=0.301

Postoperative pain 12h

I: 2 (0-4)

C: 3 (0-5)

p<0.001**

Postoperative pain 24h

I: 3 (0-5)

C: 3 (0-5)

P=0.087

Postoperative pain at movement

VAS (0-10cm)

Median (range)

Postoperative pain at PACU

I: 1 (0–4)

C: 0 (0-4)

P= 0.384

Postoperative pain 12h

I: 2 (0-4)

C: 3 (1–6)

P=0.044*

Postoperative pain 24h

I: 3 (0–6)

C: 4 (0–6)

P=0.416

Opioid consumption: Pain rescue analgesia consumption in the first 24h*

Morphine (5mg IV)

mean ± SD

I: 5±2

C: 9±2

p=0.01

Adverse events

It was reported there were no complications

related to the blocks.

Study aim: to evaluate the analgesic efficacy and safety of

SAPB in comparison with TPVB for postmastectomy

pain.

Author conclusion: The US- guided SAPB and TPVB provide good

analgesia postmastectomy, but SAPB has a superior

analgesic profile, with a longer duration of analgesia,

with delayed requirement for the first rescue analgesia

& 24 hours reduced analgesic consumption.

* Postoperative analgesia regimen was standard in all

groups. When the VAS score was greater than 4, the

patients were given morphine (5 mg IV).

Gupta (2017)

Type of study:

RCT (double‑blind, randomised, comparative study)

Setting and country:

Vardhman Mahavir Medical

College and Safdarjung

Hospital, New Delh,,

India.

Funding and conflicts of interest:

Funding: Nil.

Conflict: no conflict of interest

Inclusion criteria:

(1)patients undergoing

MRM with axillary dissection, (2) age

18–65 years, weight 40–85 kg and American Society of

Anesthesiologists Physical Status I or II.

Exclusion criteria:

contraindications to nerve block, for

example, coagulopathy and local infection at the site

of block, local anaesthetic allergy and significant

neurological, cardiac, renal, hepatic or respiratory

disease and patients planned for breast conservative

surgery/simple mastectomy with axillary clearance

N total at baseline:

I: 25

C: 25

Important prognostic factors²:

age ± SD:

I: 48.9±4.0

C: 50±10.4

ASA (I/II):

I: 23/2

C: 23/2

Groups comparable at baseline? Yes, it is reported that the

demographic data of the two groups were

comparable and that the intra‑.and post‑operative

haemodynamic parameters were also comparable

ultrasound‑guided SAP

20 ml of 0.5% bupivacaine

ultrasound‑guided PV

20 ml of 0.5% bupivacaine

Length of follow-up:

Not reported, but outcome measures reported up to 72h after surgery

Loss-to-follow-up:

I: 0

C: 0

Incomplete outcome data:

I: 0

C: 0

Postoperative pain

VAS (0–100 mm)

Mean

Postoperative pain 6h

I: 3.2

C: 3.36

p=0.46

Postoperative pain 24h

I: 2.48

C: 3.04

p=0.09

Opioid consumption: Postoperative patient-controlled analgesia morphine consumption within 24h 

mean ± SD

I: 9.7±2.1

C: 6.5±1.5

P<0.001

Adverse events

None of the patients in either group had any other complication.

Study aim: to compare the analgesic efficacy of

ultrasound‑guided PVB and SPB in patients undergoing

MRM with axillary dissection.

The primary objective of this study was to determine

the difference in the duration of analgesia of the two

blocks. The secondary objectives were to compare

the morphine consumption in 24, 48 and 72 h after

surgery, visual analogue scale (VAS) pain scores and

morphine‑related side effects (nausea/vomiting).

Author conclusion: The ultrasound‑guided SPB and PVB provide good analgesia post‑MRM, but PVB has a superior analgesic profile, with a longer duration of analgesia

the authors report on a VAS scale of 0-100mm, yet report centimeters.

Comparison 3: ESP versus SAP

Jiang (2021)

Study design: RCT; prospective

Setting and country: Affiliated Hospital of Jiaxing University, Jiaxing, China

Funding and conflicts of interest

Funding: This study was supported by The Key Discipline Established with Zhejiang Province and Jiaxing City Jointly (2019-ss-ttyx) and Key Discipline of Anesthesiology of Jiaxing City (2019-zc-06).

Conflict: The author reports no conflicts of interest in this work.

Inclusion criteria: (1) the patients needed to be aged between 18 and 80 years, (2) the American Society of Anesthesiologists (ASA) grade required was 1-2, (3) and patients needed to be prepared to undergo MRM in our hospital.

Exclusion criteria: (1) patients with shock or coma, (2) abnormal blood coagulation, (3) infection in the planned block area, (4) severe nerve injury on the side of the limb, (5) patients with a history of chronic pain and taking an analgesic, (6) patients with psychiatric diseases, (7) patents on radiotherapy and/or chemotherapy, (8) patients allergic to LAs (eg lidocaine and ropivacaine) and general anaesthetics, (9) patients and/or their families that refused surgical anaesthesia, (10) previous history of breast surgery or other chest surgery and (11) a body mass index (BMI) >34 kg/m2.

N total at baseline:

I: 30

C: 30

age (years) mean ± SD

I: 52.10 ± 11.50

C: 54.73 ± 13.60

ASA class I/II

I: 12/18

C: 13/17

Duration of surgery (min)

I: 100.96 ± 29.30

C: 109.36 ± 21.91

Groups comparable at baseline? Yes, no significant differences in basic characteristics

SAP

0.5% ropivacaine (20 mL)

ESP

20 mL of 0.5% ropivacaine

Length of follow-up:

24h

Loss-to-follow-up/ Incomplete outcome data:

Lost to follow up = 0

Analysed = 30 per group

Postoperative pain*

11-point Numerical Rating Scale (NRS), which ranges from “0” (meaning “no pain”) to “10” (meaning “worst pain imaginable”)

Results presented in figures, no absolute values available.

“the postoperative NRS score in the ESP block group at 0.5 (P < .001), 1 (P < .001), 3 (P = .037), 6 (P = .002), 12 (P = .003), 18 (P < .001) and 24 (P = .026) h after surgery when patients were active was significantly lower than that in the SAB group”

Opioid consumption: Postoperative tramadol consumption in 24 h*

Mean ± SD

I: 314.33 ± 18.88 mg

C: 273.67 ± 36.90 mg

Adverse events

block-related complications such as pneumothorax, bleeding, allergy and LA toxicity

Nothing reported.

Study aim: to analyse the postoperative analgesic effects of US-guided RIB, ESP and SAB after MRM

*Within 24 hours after the operation, the patients received an intravenous injection of tramadol 1-2 mg/kg in the surgical ward for pain relief until the NRS pain score was ≤3 in accordance with hospital policy. [..] If the postoperative NRS was greater than 3 points, tramadol 1-2 mg/kg was administered intravenously, and then the pain was evaluated after 30 minutes

Author conclusion: S-RIB and the ESP block can effectively reduce the dosage of tramadol within 24 hours after MRM, and they can effectively relieve pain within 24 hours after MRM when compared with SAB.

Shrivastava (2021)

Study design: RCT; prospective

Setting and country: ABV Government Medical College, Vidisha, Madhya Pradesh, India

Funding and conflicts of interest

Funding: -

Conflict: -

Inclusion criteria: Patients with American Society of Anesthesiologists physical status Classes I and II

Exclusion criteria:

Any patient with known allergy to the drugs used in the study, coagulation abnormalities, infection at the local site

N total at baseline:

I: 25
C: 25

age (years) mean ± SD

I: 44.40 ±10.45
C: 45.41 ±11.22

Duration of surgery (min)

I: 55±12
C: 45 ± 10

Groups comparable at baseline? Yes, no significant differences in basic characteristics

SAP

25 mL of 0.25% bupivacaine

ESP

25 mL of 0.25% bupivacaine

Length of follow-up:

24h

Loss-to-follow-up/ Incomplete outcome data:

No loss to follow up/ incomplete outcome data

Postoperative pain *

visual analog scale (VAS) using a ruler graded from 0 to 100 mm, where 0 = no pain and 100 = the worst imaginable pain

0h

I: 20
C: 20

6h

I: 20
C: 20

12h

I: 10
C: 20

24h

I: 10
C: 10

Opioid consumption: postoperative tramadol consumption in 24 h

I: 9.6±2.25
C: 15.4 ±6.15

Study aim: to compare the erector spinae plane (ESP) block and the serratus anterior plane (SAP) block, stating which is better for postoperative pain control

Author conclusion: The Serratus anterior plane block reduced postoperative tramadol and other analgesic requirements and reduced pain scores more effectively than Erector spinae plane block in the first 24 h in breast surgeries. However these blocks and the effectiveness in case of intraoperative pain relief can be tried in optimal concentrations of local anesthetics so as to reduce the complications by General anaesthesia, hereby optimising one of the limitations of this study

* When VAS score was ≥30, intravenous diclofenac 75 mg was given. If VAS was still ≥30, tramadol 50 mg was given till VAS

Comparison 4: PECS II versus PV

Jain (2020)

Study design:

RCT; prospective, randomized interventional nonblinded study

Setting and country: India Institute of Medical Sciences, New Delhi, India

Funding and conflicts of interest

Funding: Nil.

Conflict: reported that there are no conflicts of interest

Inclusion criteria: (1) ASA grades I and II (2) female patients  (3) aged 18–65 years (4) undergoing elective unilateral mastectomies with or without axillary dissection

Exclusion criteria: (1) Patients with infection at the site of proposed block, (2) chest wall deformity, (3) coagulopathy, or (4) receiving any anticoagulants, (5) body mass index ≥35 kg/m2 , (6) mental retardation were excluded from the study

N total at baseline:

I: 16

C: 15

Important prognostic factors2:

age (years) mean ± SD

I: 45.47±8.98

C: 44.47±11.62

ASA (I/II) n (%)

I: 12 (80)/3 (20)

C: 12 (80)/3 (20)

Groups comparable at baseline?

Yes, p-values demographic variables non-significant

USG modified PECS (PECS II) block

0.375% ropivacaine

USG single injection PV

0.375% ropivacaine

Length of follow-up:

Not specifically reported, but it is stated that patient was kept in PACU for 24 h postoperative period and the outcomes measurements were performed up to 24h

Loss-to-follow-up:

Reported there was no loss to follow up

Incomplete outcome data:

I: 1 did not receive allocated intervention (anatomy distorted due to previous surgery)

C: all received allocated intervention

Postoperative pain (VAS 0‑10) at rest and ipsilateral abduction of arm* with 0 corresponding to no pain and 10 being the worst imaginable pain.

“Pain scores were not significantly different among the group in the postoperative 24 h period. Only three patients gave a response at immediate postoperative and therefore VAS scores were not assessed at this point of time. At 6 h, VAS scores were reaching significant difference among PECS and SAP block.”

Opioid consumption: Postoperative fentanyl requirement in 24h in µg

(mean ± SD)[95%CI]

I: 644.67 ± 260.15 [95% CI 514.67–774.67]

C: 428.33 ± 243.1  [95% CI 308.33–548.33]

(IV morphine 10 mg = IV fentanyl 100 μg = IV sufentanil 10 μg)

In MME:

I: 64.467 ± 26.015

C: 42.833 ± 24.31 

Adverse events

No complication like inadverdent vascular puncture, pneumothorax, hypotension was seen in any group.

Study aim: to compare the postoperative 24‑h fentanyl consumption in each of the three blocks. Secondary objectives were to compare spread of local anesthetic, sensory blockade produced, onset of the sensory blockade, intraoperative opioids requirement, pain scores for 24 h postoperative period, time to first postoperative analgesia requirement and incidence of postoperative nausea and vomiting (PONV).

* Pain scores (VAS 1‑10) were measured at rest and ipsilateral abduction of arm at 1, 2, 3, 6, 12, and 24‑hour postoperative.

à very limited results

Author conclusion: TPVB and SAP group provide equivalent analgesia in patients undergoing mastectomies. PECS II block is inferior to TPVB and SAP block in providing analgesia for breast surgeries. Single‑shot TPVB and SAP block also result in greater spread of the drug along with sensory block compared to PECS II block. SAP block is easier to perform than TPVB with lesser chances of complications and results in faster onset. Thus, we recommend SAP block for patients undergoing mastectomies for effective analgesia

Comparison 5: PECS II versus SAP

Bakeer (2020)

Study design: RCT; prospective

Setting and country: National Cancer Institute, Egypt

Funding and conflicts of interest

Funding: not reported

Conflict: the authors report no conflicts of interest

Inclusion criteria:

aged 18–60 years, with an American Society of Anesthesiologists (ASA) class II scheduled for unilateral modified radical mastectomy (MRM).

Exclusion criteria:

Patients with a history of bleeding diathesis, relevant drug allergy, opioid dependence, local sepsis, psychiatric illnesses

N total at baseline:

I1: 60

I2: 60
C:  60

age (years) mean ± SD

I1: 50.8±8.9

12: 50.9±6.8

Duration of surgery (min)

I1: 155±53

12: 158±34

Groups comparable at baseline?

There was no significant difference in the patients’ demographic data and duration of surgery between all groups

I1: PECSII block with 30 mL of bupivacaine 0.25%

I2: SAP using the same volume of bupivacaine 0.25%

Length of follow-up:

24h

Loss-to-follow-up/ Incomplete outcome data:

two patients in the control group refused to continue the study, three patients in the PECS group, and two patients in the serratus group were excluded due to failed block

sample for analyses:

I1: 57

I2: 58
C:  58

Postoperative pain

visual analogue scale (VAS) where 0 =no pain and 10 = the worst imaginable pain

median (range)

At rest

immediate postop

I1: 0 (0–3)

I2: 0 (0–2)

at 12h

I1: 0 (0–3)

I2: 0 (0–2)

at 24h

I1: 0 (0–2)

I2: 0 (0–2)

At shoulder movement

immediate postop

I1: 0 (0–3)

I2: 1 (0–3)

at 12h

I1: 1 (0–3)

I2: 1 (0–3)

at 24h

I1: 1 (0–3)

I2: 1 (0–3)

Opioid consumption: postoperative morphine consumption in 24 h*

I1: single dose of 2 mg

I2: single dose of 2 mg

No. (%) of patients requiring postoperative morphine

I1: 11 (19.3%)

I2: 14 (24.1%)

Adverse events

No cases of pneumothorax, local anesthetic toxicity, or opioid side effects as respiratory depression, pruritus, or urinary retention were recorded

Study aim: We assumed that PECSII could safely provide a better analgesic profile with an opioid-sparing effect than SAPB. We performed this study to evaluate this assumption.

Primary and secondary outcome measures: The total amount of morphine consumed in the first 24 postoperative hours was the primary outcome measure.

Secondary outcomes were the intraoperative fentanyl requirements, time to first rescue analgesia and VAS scores at rest and during shoulder movement immediately postoperative (defined as 15 min post-extubation) and at 1 hour, 4 hours, 8 hours, 12 hours and 24 hours postoperatively. Ramsey sedation score (RSS) was assessed at the same time points. Heart rate and MAP were recorded intraoperatively (1-minute pre-incision, 1-minute postincision) and postoperatively at 1, 4, 8, 12, 24 hours. Postoperative nausea and vomiting (PONV) were rated on a four-point verbal scale (none =no nausea, mild = nausea but no vomiting, moderate = vomiting one attack, severe = vomiting > one attack). PONV was treated by 10mg metoclopramide slowly IV. All other complications such as pneumothorax, local anesthetic systemic toxicity, respiratory depression defined as a respiratory rate

* Fewer patients in the PECS and SAPB groups needed morphine injections during the first 24 hours compared to the control group (p < 0.001). Those who requested morphine in the PECS and SAPB groups consumed a single dose of 2 mg, while the median consumed dose in the control group was 7 mg (range: 2–12) (p < 0.001)

Jain (2020)

Study design:

RCT; prospective, randomized interventional nonblinded study

Setting and country: India Institute of Medical Sciences, New Delhi, India

Funding and conflicts of interest

Funding: Nil.

Conflict: reported that there are no conflicts of interest

Inclusion criteria: (1) ASA grades I and II (2) female patients  (3) aged 18–65 years (4) undergoing elective unilateral mastectomies with or without axillary dissection

Exclusion criteria:

Patients with infection at the site of proposed block, chest wall deformity, coagulopathy, or receiving any anticoagulants, body mass index ≥35 kg/m2 , mental retardation were excluded from the study

N total at baseline:

I: 16

C: 15

Important prognostic factors²:

age (years) mean ± SD

I: 45.47±8.98

C: 60.87±11.9

ASA (I/II) n

I: 12/3

C: 11/4

Surgical duration in min

I: 109±27.14

C: 100.67±28.53

Groups comparable at baseline?

Yes, p-values demographic variables non-significant

USG modified PECS (PECS II) block

30ml 0.375% ropivacaine

USG SAP

30ml 0.375% ropivacaine

Length of follow-up:

Not specifically reported, but it is stated that patient was kept in PACU for 24 h postoperative period and the outcomes measurements were performed up to 24h

Loss-to-follow-up:

Reported there was no loss to follow up

Incomplete outcome data:

I: PECS group: did not receive allocated intervention (anatomy distorted due to previous surgery)

C: SAP group: all received allocated intervention

Postoperative pain (VAS 0‑10) at rest and ipsilateral abduction of arm* with 0 corresponding to no pain and 10 being the worst imaginable pain.

“Pain scores were not significantly different among the group in the postoperative 24 h period. Only three patients gave a response at immediate postoperative and therefore VAS scores were not assessed at this point of time. At 6 h, VAS scores were reaching significant difference among PECS and SAP block.”

Opioid consumption: Postoperative fentanyl requirement in 24h in µg

(mean ± SD)[95%CI]

I: PECS: 644.67 ± 260.15 [95% CI 514.67–774.67]

C: SAP: 415 ± 182.44 [95% CI 323–507]

Adverse events

No complication like inadverdent vascular puncture, pneumothorax, hypotension was seen in any group.

Study aim: to compare the postoperative 24‑h fentanyl consumption in each of the three blocks. Secondary objectives were to compare spread of local anesthetic, sensory blockade produced, onset of the sensory blockade, intraoperative opioids requirement, pain scores for 24 h postoperative period, time to first postoperative analgesia requirement and incidence of postoperative nausea and vomiting (PONV).

* Pain scores (VAS 1‑10) were measured at rest and ipsilateral abduction of arm at 1, 2, 3, 6, 12, and 24‑hour postoperative.

à very limited results

Conclusion: TPVB and SAP group provide equivalent analgesia in patients undergoing mastectomies. PECS II block is inferior to TPVB and SAP block in providing analgesia for breast surgeries. Single‑shot TPVB and SAP block also result in greater spread of the drug along with sensory block compared to PECS II block. SAP block is easier to perform than TPVB with lesser chances of complications and results in faster onset. Thus, we recommend SAP block for patients undergoing mastectomies for effective analgesia

Fuiji 2019

Study design:

RCT

Setting and country: Nagoya University Hospital, Nagoya, Japan

Funding and conflicts of interest

No external funding or competing interests declared

Inclusion criteria:

women scheduled for breast cancer resection by mastectomy at the Nagoya University Hospital, Nagoya, Japan, between August 2015 and August 2018. Participants were ≥ 20 years old and ASA physical status 1 or 2.

Exclusion criteria: We did not study women: < 20 years old or ASA physical status > 2; with estimated glomerular filtration rate < 30 ml.min1 .1.73 m2 or Child–Pugh liver score ≥ B; allergic to ropivacaine; who had mastectomy that was radical, partial or followed by immediate reconstruction or within six months of previous mastectomy.

N total at baseline:

I: 40

C: 40

Important prognostic factors²:

age (years) mean ± SD

I: 58.4 ± 12.7

C: 57.9 ±  13.4

ASA (I/II) n (%)

I: 26/14

C: 30/10

Operation time (min)

I: 111 ± 36

C: 122 ± 49

Groups comparable at baseline?

Yes, no sig. p-values on baseline characteristics

PECS II block

10 ml ropivacaine 0.5% and 20 ml ropivacaine 0.5%

SAP

30 ml ropivacaine 0.5%

Length of follow-up:

6 postoperative months

Loss-to-follow-up:

no loss to follow up

Incomplete outcome data:

Not reported, but clear that there was none

Postoperative pain 24h

a 0–100 mm visual analogue scale (VAS)

median (IQR [range])

I: 18 (11–27 [0–61]) mm

C: 23 (11–35 [0–70]) mm

Opioid consumption: Morphine consumption in first 24 h

median (IQR [range])

I: 4 (2–7 [0–37]) mg

C: 6 (3–9 [1–25]) mg

Chronic pain after 6 months

11-point numerical rating scale (NRS), defined as: 1–3, mild pain; 4–6, moderate pain; and 7–10, severe pain

moderate or severe chronic pain n (%)

I: 4/40 (10%)

C: 13/40 (33%)

adjusted OR (95%CI) 0.23 (0.07–0.80), p = 0.02

Study aim: to test the effects of the PECS 2 block compared with the serratus plane block for pain after mastectomy.

Primary and secondary outcomes

We defined the primary outcome as the rate of pain worse than mild at six postoperative months.

Secondary outcomes at six postoperative months were the rate of participants without pain and the health-related quality of life. Acute secondary outcomes were morphine consumption within 24 postoperative hours and the pain score.

Authors conclusion: In conclusion, the PECS 2 block reduced chronic pain six months after mastectomy compared with serratus plane block

Study reference

Study characteristics

Patient characteristics

Intervention (I)

Comparison / control (C)

Follow-up

Outcome measures and effect size

Comments

Comparison 2: ESP versus PV

Xiong, 2021

[individual study characteristics deduced from Xiong, 2021]

PS., study characteristics and results are extracted from the SR (unless stated otherwise)

SR and meta-analysis of

Literature search up to April 2021

10 RCTs, 4 included in current analysis

A: Gurkan, 2020

B: Moustafa, 2020

C: Swisher, 2020

D: Ghamry, 2019

Study design:

RCT

Setting and Country:

Single-center, China

Source of funding and conflicts of interest:

Funding: This study was supported by the Science and Technology Research Project of Jinhua (http:// kjj.jinhua.gov.cn/art/2021/4/2/art_1229317787_ 3832377.html), grant number (2021-4-004). Xiong Chang was responsible for this. The sponsors decided to publish this study

Conflict: The authors have declared that no competing interests exist.

Inclusion criteria SR: (1) RCTs; (2) Adult patients (over 18 years old) who underwent thoracic or breast surgery; (3) Interventional use of PVB for postoperative analgesia (PVB group); (4) Use of ESPB for postoperative analgesia (ESPB group) in the control group.

Primary outcomes  RS: Pain scores at rest and movement at 0–1, 4–6, 8–12, and 24 hours after surgery

Secondary outcomes SR: Opioid (morphine equivalent) consumption at 24 hours after surgery; Incidence of additional analgesia in 24 hours post-operation; Time required for completing block procedure; Incidence of postoperative nausea and vomiting (PONV); publication bias

Exclusion criteria SR: (1) Incomplete studies; (2) Unreported relevant outcomes.

10 studies included (4 in current analysis)

Important patient characteristics at baseline:

N, mean age (I/C)

A: 25/25, 49.08/49.4

B: 45/45, -

C: 50/50, 55.4/55.4

D: 35/35, 37.7/41

Duration of surgery (min.)

A: 89.4/82.2

B: -

C: 77.9/75.7

D: 170/ 173.2

Country

A: Turkey

B: Egypt

C: USA

D: Egypt

Groups comparable at baseline? Yes

ESP

A: 20 ml 0.25% bupivacaine

B: 20 ml 0.25% bupivacaine

C: 25 ml 0.5% ropivacaine unilateral

D: 20 ml of 0.25% bupivacaine

PV

A: 20 ml 0.25% bupivacaine

B: 20 ml 0.25% bupivacaine

C: 25 ml 0.5% ropivacaine unilateral

D: 20 ml of 0.25% bupivacaine

End-point of follow-up:

Not reported, but results up to 24h post-surgery

For how many participants were no complete outcome data available?

(intervention/control)

Not reported

Postoperative pain

(MDs were reported)

Mean ± SD

At rest 0-1h

A: I: 2 ± 2.22
C: 0.66 ± 1.48

C: I: 3 ± 1.48
C: 2.83 ± 2.96

D: I: 1.33 ± 0.74
C: 1.33 ± 0.74

N=100 (MD =-0.39, 95%

CI [-1.12, 0.35].

heterogeneity (P=0.06, I2=65%). [but comparison different way around]

At rest 4-6h

A: I: 1 ±1.48
C: 0.88 ± 1.11

D: I: 1.62 ± 0.5
C: 1.5 ± 0.5

N=60 (MD =-0.12, 95%

CI [-0.34, 0.10].

heterogeneity (P=1.00, I2=0%). [but comparison different way around]

At rest 8-12h

A: I: 0.66 ± 1.48
C: 1 ± 1.48

D: I: 3 ± 1.48
C: 3.25 ± 2.03

N=60 (MD =0.30, 95%

CI [-0.29, 0.88].

heterogeneity (P=0.88, I2=0%). [but comparison different way around]

At rest 24h

A: I: 0.33 ± 0.74
C: 0.66 ± 1.48

C: I: 3 ± 1.48
C: 2.83 ± 2.96

D: I: 3.5 ± 2.2
C: 3 ± 1.48

N=60 (MD =-0.03, 95%

CI [-0.53, 0.47].

heterogeneity (P=0.31, I2=16%). [but comparison different way around]

Postoperative opioid consumption at 24h

Mean ± SD

A: I: 5.6 ± 3.43
C: 5.64 ± 4.15

B: I: 6.17 ± 2.08
C: 6.22 ± 2.09

C: I: 5 ± 7.63
C: 8.3 ± 11.4

D: I: 26.7 ± 2.1
C: 27.3 ± 2.9

N=155 (MD =0.31, 95%

CI [-0.34, 0.97].

heterogeneity (P=0.39, I2=1%). [but comparison different way around]

SR aim: to assess the postoperative analgesic effects of PVB and ESPB for thoracic and breast surgery

SR conclusion: The postoperative analgesic effects of PVB versus ESPB are distinguished by the surgical site. For thoracic surgery, the postoperative analgesic effect of PVB is better than that of ESPB; for breast surgery, the postoperative analgesic effects of PVB and ESPB are similar. At the same time, there is no significant statistical difference between the two postoperative analgesic techniques in PONV, but the block procedure time required for ESPB is significantly shorter than that for PVB. Therefore, when choosing postoperative analgesia techniques, the results of this meta-analysis recommend PVB for thoracic surgery and ESPB for breast surgery.

Quality assessment:

The quality of included RCTs was assessed by two independent researchers (Chang Xiong and Chengpeng Han) using the Cochrane Collaboration Risk of Bias tool and the Jadad Score.

Six studies [18,20–24] displayed a high risk of bias arising from detection, attrition and reporting. The remaining four articles [19,25–27] had unclear risks of bias. The outcomes of risk assessment are presented in Fig 2. All trials were identified as high quality, according to the Jadad Score. The Jadad Score is shown in Table 1.

A, B, C, D = high risk of bias

No GRADE

Publication bias

No substantial asymmetry was detected throughout visual examination of the funnel plot (S1 Fig). Also, the Egger’s test showed that the P-value for each outcome was greater than 0.1, indicating no publication bias existed in this meta-analysis (S1 Table).

Comparison 4: PECS II versus PV

Elshanbary,

2021

[individual study characteristics deduced from Elshanbary,

2021]

PS., study characteristics and results are extracted from the SR (unless stated otherwise)

SR and meta-analysis of

Literature search up to July 2020

A: Abo-Sabaa 2019

B: Siddeshwara 2019

C: Tripathy 2019

D: Annamalai 2017

E: Syal &Chandel 2017

F: Kulhari 2016

G: Wahba & Kamal 2014

Study design:

RCT [parallel]

Setting and Country:

Multi-center, Egypt and Palestine

Source of funding and conflicts of interest:

Funding: not reported

Conflict: the authors declare no conflict of interest

Inclusion criteria SR: (1) female adult patients undergoing breast cancer surgeries (2) studies that compared Pecs I or Pecs II to other methods of analgesia.

Exclusion criteria SR: (1) observational, retrospective, and animal studies, theses, reviews, abstracts, nonrandomized clinical trials, and studies including patients undergoing breast augmentation surgery

47 studies included (7 in current analysis)

Important patient characteristics at baseline:

N, mean age (I/C)

A: 24/25, 48.37/47.8
B: 20/20, 45.96/46.54
C: 29/29, 52.4/51.8
D: 30/30, 46.3/46.9
E: 20/20, 46.03/44.50
F: 20/20, 52/48.4
G: 30/30, 49.9/49.9

ASA Status I:II (I/C)

A: 14:16/15:15
B: 13:7/15:5
C: 16:10/16:11
D: -
E: 13:7/14:6
F: 9:11/ 14:6
G: 18:12/20:10

Type of surgery

A: MRM, lumpectomy, simple mastectomy, ALND
B: MRM
C: MRM with ALND
D: MRM
E: MRM
F: MRM
G: MRM

PECS II

*A: 20 ml of 0.25% bupivacaine+ 10 ml of 0.25% bupivacaine

*B: 15 ml mixture of levobupivacaine 0.25% and dexamethasone + 10 ml mixture of levobupivacaine 0.25% and dexamethasone

*C: 30 ml of 0.1% lignocaine + 0.25% bupivacaine + 1 μg/kg dexmedetomidine

*D: -

*E: 10 ml 0.5% bupivacaine (50 mg) with 0.5 ml of adrenaline 1:10000 (50 μg)+ 10 ml of bupivacaine 0.5% (50 mg) with 0.5 ml of adrenaline 1:10000 (50 μg)

*F: ropivacaine 0.5%, 25 ml

*G: 10 ml of levobupivacaine 0.25% + 20 ml levobubivacaine 0.25%

PV

*A: 20 ml of 0.25% bupivacaine

*B: 25 ml levobupivacaine 0.25% and dexamethasone

C: 30 ml of 0.1% lignocaine + 0.25% bupivacaine + 1 μg/kg dexmedetomidine

*D: -

*E: 20 ml of 0.5% bupivacaine to which 1 ml of 1:10000 dilution adrenaline [100 μg]

*F: ropivacaine 0.5%, 25 ml

*G: 15–20 ml of levobupivacaine 0.25%

End-point of follow-up:

For how many participants were no complete outcome data available?

(intervention/control)

Not reported

Postoperative pain

Not reported how measured.

Mean ± SD

At 0h

A: I: 0.4 ± 0.5

C: 1.43 ± 0.82

B: I: 3.67 ± 0.79

C: 5 ± 2.59

C: -

D: -

E: I: 2.67 ± 0.79

C: 3.67 ± 0.79

F: I: 1.16 ± 0.37

C: 2 ± 0

G: -

N=91 (SMD =-1.15, 95%

CI [-1.63, -0.67], P= 0.17).

Heterogeneity (P<0.00001, I2=43%)

At 6h

A: I: 2.2 ± 1.06

C: 2.8 ± 1

B: I: 3 ± 2.59

C: 4 ± 1.59

C: -

D: -

E: I: 4 ± 1.58

C: 4 ± 1.58

F: I: 2.16 ± 0.37

C: 2.5 ± 1.2

G: I: 4.67 ± 0.73.90.8

C: 5 ± 1.56

N=121 (SMD =-0.34, 95%

CI [-0.60, -0.09].

heterogeneity (P=0.69, I2=0%)

At 12h

A: I: 1.87 ± 1.53

C: 2.97 ± 0.67

B: I: 4 ± 1.59

C: 5 ± 1.59

C: -

D: -

E: I: 4.33 ± 0.79

C: 3.33 ± 0.79

F: I: 1.33 ± 0.79

C: 2.17 ± 1.99

G: I: 3.67 ± 0.78

C: 4 ± 1.56

N=120 (SMD =-0.24, 95%

CI [-0.92, 0.44].

heterogeneity (P<0.0001, I2=85%)

At 24h

A: I: 2.33 ± 0.76

C: 2.3 ± 0.47

B: I: 4 ± 1.59

C: 5 ± 1.59

C: -

D: -

E: I: 4 ± 1.59

C: 3 ± 1.59

F: I: 1 ± 0.01

C: 1 ± 0.01

G: I: 5.33 ± 0.78

C: 3 ± 1.56

N=120 (SMD =0.38, 95%

CI [-0.42, 1.18].

heterogeneity (P<0.0001, I2=89%)

Postoperative opioid consumption

Not reported how measured or which opioid

Mean ± SD

A: I: 7.5 ± 2.53

C: 10 ± 0

B: I: 11.25  ± 4.75

C: 15 ± 4.86

C: I: 1.21 ± 1.2

C: 1.07 ± 1.1

D: -

E: I: 0.5 ± 0.5

C: 0.2 ± 0.4

F: I: 3.9 ± 0.79

C: 5.3 ± 0.98

G: I: 22 ± 3.7

C: 27 ± 6.67

N= 287 (SMD =-0.48, 95%

CI [-1.20, 0.24], P= 0.19) (Fig. 4). Pooled results were

heterogeneous (P<0.00001, I2=86%) and the heterogeneity could not be solved by leave 1 out.

*extracted from individual studies

Aim: to compare Pecs block methods with control and other techniques, including PVB, ESPB, and LA methods, and to measure the effect of the addition of dexmedetomidine to Pecs II block.

*Methods:

A: Pain: VAS 0-10cm

Opioid: total morphine rescue

B: Pain: NRS

Opioid: morphine

C: Pain: VAS 0-10cm

Opioid: -

D:

E: Pain: VAS 0-10cm

Opioid: fentanyl

F: Pain: VAS 0-10

Opioid: patient-controlled morphine

G: Pain: NRS 0-10

Opioid: morphine

Brief description of conclusion individual studies (table 2)

A: Simple mastectomy,

with a lack of contraindications and side effects
B: Adding levobupivacaine and dexamethasone to Pecs II block increased the duration of analgesia without any side effects
C: Both Pecs and PVB prolonged analgesia without opioids, but Pecs block produce anesthesia in a shorter time
D:  Pecs II block is an alternative technique to PVB for postsurgical pain. It gives more analgesia and fewer

complications
E: PVB reduced postoperative pain and elongated the duration of analgesia the first 24 h, compared with Pecs II block
F: Pecs II block showed higher postoperative analgesia without

producing any side effects, compared with PVB
G: Pecs block decreased postsurgical morphine usage in the first 24 h and pain scores in the first 12 h, compared with PVB

Author conclusion: In conclusion, the Pecs block increases the analgesia quality in BC surgeries; reduces intraoperative and postoperative opioid consumption compared with control and ESPB. Furthermore, Pecs II block reduces the number of patients required analgesia and increases the duration of analgesia compared with control. Compared with PVB, Pecs II is better regarding pain relief. The combination of Pecs II with dexmedetomidine showed lower postoperative opioid consumption with increased duration of analgesia and better pain relief. We recommend Pecs II block to be a first-line option for analgesia in BC surgery.

Quality assessment:

The quality of the included RCTs was moderate to high. We analyzed all outcomes related to BC surgeries. We used the random-effect model for analysis and did a sensitivity analysis, and assessed the publication bias.

GRADE not included

Comparison 6: PECS II versus ESP

Elshanbary,

2021

[individual study characteristics deduced from Elshanbary,

2021]

PS., study characteristics and results are extracted from the SR (unless stated otherwise)

SR and meta-analysis of

Literature search up to July 2020

A: Altıparmak, 2018

B: Gad, 2019

C: Sinha, 2019

Study design:

RCT [parallel]

Setting and Country:

Multi-center, Egypt and Palestine

Source of funding and conflicts of interest:

Funding: not reported

Conflict: the authors declare no conflict of interest

Inclusion criteria SR: (1) female adult patients undergoing breast cancer surgeries (2) studies that compared Pecs I or Pecs II to other methods of analgesia.

Exclusion criteria SR: (1) observational, retrospective, and anim23al studies, theses, reviews, abstracts, nonrandomized clinical trials, and studies including patients undergoing breast augmentation surgery

47 studies included (3 in current analysis)

Important patient characteristics at baseline:

N, mean age (I/C)

A: 18/20; 53.56/57.55

B: 23/24; 53.80/53.63

C: 30/30; 49.6/48.61

ASA Status I:II (I/C)

A: 8:10/7:13

B: -

C: 20:10/22:8

Type of surgery

A: MRM+ALND
B: MRM

C: MRM

*Country

A: Turkey
B: Egypt

C:  India

Groups comparable at baseline?

PECS II

*A: 10 ml of 0.25% bupivacaine + 20 ml of bupivacaine 0.25%

*B: 10ML+20ML - 0.25% levobupivacaine plus 0.5 μ/kg dexmedetomidine

*C: 2 ml of 2% lignocaine; 15 ml of 0.2% ropivacaine; 10 ml of 0.2% ropivacaine

ESP

*A: 2-3ml of isotonic saline solution + 20 ml of bupivacaine

*B: 20ML - 0.25% levobupivacaine plus 0.5 μ/kg dexmedetomidine

*C: 2 ml of 2% lignocaine; 20 ml of 0.2% ropivacaine was injected

*End-point of follow-up:

A: 24h

B: 24h

C: 24h

*For how many participants were no complete outcome data available?

A: I: 2/ C: 0

B: I: 2/ C: 1 (lost to follow-up)

C: none

Postoperative pain

Not reported how measured.

Mean ± SD

At 6h

A: I: -

C: -

B: I: 20 ± 5

C: 22.5 ± 7.5

C: I: 2.73 ± 0.78

C: 3.3 ± 0.82

At 12h

A: I: 2 ± 1

C: 2.75 ± 0.75

B: I: 20 ± 10

C: 27.5 ± n7.5

C: 3.1 ± 0.7

C: 3.3 ± 0.69

At 24h

A: I: 1.25 ± 0.75

C:  1.25 ± 0.75

B: I: 12.5 ± 7.5

C: 12.5 ± 7.5

C: I: 2.23 ± 0.632

C: 2.6 ± 0.48

Postoperative opioid consumption

Not reported how measured or which opioid

Mean ± SD

A: I: 132.78 ± 22.44

C: 196 ± 27.03

B: I: 10.73 ± 3.12

C: 16.7 ± 7.2

C: I: 4.4 ± 0.94

C: 6.59 ± 1.35

*extracted from individual studies

Aim: to compare Pecs block methods with control and other techniques, including PVB, ESPB, and LA methods, and to measure the effect of the addition of dexmedetomidine to Pecs II block.

*Method:

A: Pain: NRS 0-10

Opioid: tramadol
B: Pain: VAS 0-100mm

Opioid: morphine
C: Pain: NRS 0-10

Opioid: morphine (mg)

Brief description of conclusion individual studies (table 2)

A: Pecs II block decreased postsurgical opioid usage and pain scores compared with ESPB
B: Pecs II block yields better quality of analgesia than ESPB
C: Pecs II block reduced pain scores with opioid usage in comparison with ESPB

Author conclusion: In conclusion, the Pecs block increases the analgesia quality in BC surgeries; reduces intraoperative and postoperative opioid consumption compared with control and ESPB. Furthermore, Pecs II block reduces the number of patients required analgesia and increases the duration of analgesia compared with control. Compared with PVB, Pecs II is better regarding pain relief. The combination of Pecs II with dexmedetomidine showed lower postoperative opioid consumption with increased duration of analgesia and better pain relief. We recommend Pecs II block to be a first-line option for analgesia in BC surgery.

Quality assessment/ publication bias:

The quality of the included RCTs was moderate to high. We analyzed all outcomes related to BC surgeries. We used the random-effect model for analysis and did a sensitivity analysis, and assessed the publication bias.

GRADE not included