Retrolaminar versus erector spinae plane block for enhanced recovery after cesarean section: a retrospective study

Abstract

Background

The global rise in cesarean section (CS) rates has made effective, opioid-sparing postoperative analgesia a clinical priority. The erector spinae plane block (ESPB) and retrolaminar block (RLB) are trunk blocks increasingly incorporated into multimodal analgesia protocols; however, comparative evidence between these two techniques following CS remains limited.

Methods

This retrospective, single-center study analyzed adult women undergoing elective CS under spinal anesthesia, without the use of general anesthesia. The primary outcome was total tramadol consumption within 24 h postoperatively. Secondary outcomes included time to first rescue analgesia, VAS scores at 1, 6, 12, and 24 h, 24-h ObsQoR-11 T score, time to discharge, and incidence of adverse events.

Results

Of 126 screened patients, 122 were analyzed (ESPB n = 64; RLB n = 58). ESPB significantly reduced 24-h tramadol consumption compared with RLB (130.94 mg vs. 141.9 mg; p = 0.001) and prolonged the time to first rescue analgesia (7.86 ± 1.50 vs. 6.78 ± 1.28 h; p = 0.001). VAS scores were significantly lower in the ESPB group at 6 h (p = 0.005) and 12 h (p < 0.001), with no differences at 1 or 24 h. ObsQoR-11 T scores and discharge times were comparable between groups. Adverse events were infrequent; hypotension occurred in 10.9% of ESPB patients and 5.2% of RLB patients (p = 0.246).

Conclusions

In elective CS, ESPB provided superior early postoperative analgesia and reduced opioid consumption compared to RLB. ESPB appears to be a rational choice when prolonged analgesia and opioid sparing are prioritized in the early postoperative period, whereas RLB may serve as a reliable alternative in settings emphasizing technical simplicity and hemodynamic stability.

Introduction

Globally, cesarean section (CS) delivery rates are increasing rapidly, with estimates suggesting that they will reach approximately 30% by 2030—equating to nearly 38 million CS procedures worldwide (Betran et al. 2021). Türkiye ranks among the countries with the highest CS rates, at 50.8%, making postoperative pain management a significant clinical concern (Anyaehie et al. 2022). Post-cesarean pain is typically most intense during the first 24–72 h after surgery and has both somatic and visceral components. Inadequate pain control may delay early mobilization, negatively impact breastfeeding initiation, and increase the risk of postpartum depression (Shen et al. 2020). Therefore, effective and safe postoperative analgesia not only enhances maternal comfort but also facilitates optimal maternal–infant bonding.

In recent years, truncal blocks have gained prominence as part of multimodal analgesia protocols. Retrolaminar block (RLB) and erector spinae plane block (ESPB) have emerged as effective approaches for postoperative pain control. ESPB has been shown to reduce pain scores, improve patient satisfaction, and decrease analgesic requirements (Ribeiro Junior et al. 2022). RLB, on the other hand, provides a distinct ultrasonographic landmark at the laminar level, offering a technically straightforward and safe alternative with potential to reduce postoperative opioid consumption (Liu et al. 2021). However, comparative studies evaluating ESPB and RLB in terms of postoperative pain control, total opioid use, time to first rescue analgesia, and patient satisfaction remain limited, and existing findings are heterogeneous.

The primary aim of this study was to compare the postoperative analgesic efficacy of RLB and ESPB in patients undergoing CS, specifically focusing on opioid consumption and time to first rescue analgesia. Secondary outcomes included postoperative recovery quality assessed using the Turkish version of the Obstetric Quality-of-Recovery Score (ObsQoR-11 T), a validated patient-reported outcome measure. This study aims to contribute evidence-based data toward optimizing postoperative analgesia strategies following cesarean delivery.

Methods

Study design and setting

This retrospective, single-center study was conducted at Elazığ Fethi Sekin City Hospital, a tertiary healthcare institution located in Elazığ, Türkiye. The study included adult women who underwent elective CS under spinal anesthesia between July 1 and September 20, 2025, and who received either an ESPB or a RLB for postoperative analgesia. Data—including pain scores, recovery quality assessments, and analgesic requirements—were retrospectively collected from electronic medical records using standardized data extraction procedures.

The study protocol was registered on ClinicalTrials.gov (NCT07181902). Ethical approval was obtained from the local ethics committee prior to data analysis (Decision No: 2025/16–03). The study was conducted in accordance with the principles outlined in the Declaration of Helsinki. A detailed flow diagram illustrating patient inclusion, group allocation (ESPB and RLB), and data analysis procedures is presented in Fig. 1. The study was designed and reported in compliance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines (Figs. 2 and 3).

Fig. 1.

Flow of patients included in the retrospective study of RLB versus ESPB for CS

Fig. 2.

Total Tramadol Consumption (mg) in the first 24 hours postoperatively. ESP = Erector spinae plane block; RLB = Retrolaminar block; *p < 0.05 indicates statistical significance

Fig. 3.

Comparison of postoperative VAS scores between groups. ESP = Erector spinae plane block; RLB = Retrolaminar block; VAS = Visual analog scale; ^# p < 0.05 indicates statistical significance

Participants

This retrospective cohort included adult women who underwent elective CS under spinal anesthesia at Elazığ Fethi Sekin City Hospital.

Inclusion criteria

Eligible participants met all of the following criteria:

• Women aged 18–45 years who underwent elective CS under spinal anesthesia.

• Received either a RLB or an ESPB for postoperative analgesia.

• Singleton pregnancy with a gestational age ≥ 37 weeks.

• American Society of Anesthesiologists (ASA) Physical Status II–III.

• Availability of a completed ObsQoR-11 T questionnaire in medical records.

Exclusion criteria

Patients were excluded if any of the following applied:

• Emergency CS or preterm delivery (< 37 weeks).

• Multiple pregnancy or severe maternal/obstetric complications (e.g., preeclampsia, placenta previa, placenta accreta spectrum).

• Body mass index (BMI) ≥ 40 kg/m².

• Significant systemic diseases (e.g., severe cardiac, respiratory, renal, or hepatic disorders).

• Fetal or placental anomalies.

• History of chronic pain syndromes, opioid dependence, or long-term analgesic use.

• Neurological, psychiatric, or cognitive disorders that could interfere with pain perception or completion of the ObsQoR-11 T questionnaire.

• Incomplete postoperative ObsQoR-11 T data or insufficient clinical documentation.

• Cases in which an adequate sensory block could not be achieved within the expected dermatomal distribution after block administration were defined as block failures and excluded from the final analysis.

Protocol and outcome measures

Anesthesia and postoperative analgesia

All patients underwent the standard spinal anesthesia protocol routinely practiced at our institution. According to this protocol, spinal anesthesia was administered using 10–12.5 mg of 0.5% hyperbaric bupivacaine (Heavy Marcaine®). Intrathecal opioids or adjuvant agents (morphine, fentanyl, clonidine, or dexamethasone) were not routinely used. Adequate sensory blockade up to the T4–T6 dermatome level was confirmed in all patients prior to the start of surgery. A retrospective review of anesthesia records verified full adherence to this protocol in all included cases. As part of the hospital’s standard recovery protocol, all patients received 1 g of intravenous paracetamol and 50 mg of intravenous dexketoprofen approximately 30 min before the end of surgery.

In our institution, truncal blocks are routinely recommended to all patients undergoing elective CS under spinal anesthesia, unless a contraindication exists (e.g., patient refusal, coagulopathy, infection at the injection site). ESPB and RLB were performed after completion of surgery during the postoperative period, following regression of the motor and sensory effects of spinal anesthesia. For postoperative analgesia, patients who received bilateral ultrasound-guided ESPB or RLB at the T9 level in the lateral position, using 20 mL of 0.25% bupivacaine on each side, were included in the study. All blocks were performed by anesthesiologists experienced in regional anesthesia under real-time ultrasound guidance. Block efficacy was indirectly evaluated based on postoperative analgesic effectiveness, including VAS pain scores and analgesic requirements. Blocks that failed to provide adequate analgesia during the specified postoperative time periods were excluded from the analysis.

After the procedure, patients were monitored in the post-anesthesia care unit until clinical stability was achieved and were transferred to the postpartum ward once a Modified Aldrete Score of ≥ 9 was reached. Postoperative assessments included pain intensity measured using the Visual Analog Scale (VAS) at 1, 6, 12, and 24 h, and recovery quality assessed using the ObsQoR-11 T at 24 h.

Patients were retrospectively categorized according to the type of block received:

• Group ESPB: Patients who underwent cesarean section under spinal anesthesia and received bilateral ESPB at the T9 level under ultrasound guidance for postoperative analgesia.

• Group RLB: Patients who underwent cesarean section under spinal anesthesia and received bilateral RLB at the T9 level under ultrasound guidance for postoperative analgesia.

Surgical technique

Only cases performed with a standardized surgical technique were included in the study. All elective cesarean sections were performed using the same skin incision and a lower segment transverse uterine incision. To eliminate potential variations that could influence postoperative pain and recovery scores, the incision type, surgical approach, and closure technique were kept consistent across all patients. Surgical details were retrospectively reviewed from patient records to confirm protocol adherence.

Primary outcomes

• Total Analgesic Consumption: The total amount of tramadol (mg) administered within the first 24 hours postoperatively.

Secondary outcomes

• Analgesic Requirements: The time to the first rescue analgesia was recorded. The rescue analgesia threshold was defined as a VAS score ≥ 4, at which point intravenous tramadol (0.75 mg/kg) was administered according to the institutional protocol.

• Quality of Recovery: Postoperative recovery quality was evaluated at 24 h using ObsQoR-11 T, which assesses multidimensional aspects of recovery including patient comfort, physical and emotional well-being, and functional status.

• Postoperative Pain Intensity: Pain intensity was assessed using the VAS at 1, 6, 12, and 24 h postoperatively.

• Adverse Events: Incidences of postoperative nausea and vomiting (PONV; defined as requiring antiemetic therapy), hypotension (systolic blood pressure < 90 mmHg or ≥ 20% reduction from baseline), bradycardia, injection-site complications, or other block-related adverse events were recorded from clinical documentation.

• Demographic and Clinical Characteristics: Age, BMI, ASA-physical status, comorbidities, medications, and obstetric history (parity, gestational age).

• Surgical and Anesthetic Data: Duration of cesarean section and duration of anesthesia.

Sample size and statistical analysis

The sample size was calculated based on the anticipated difference in the primary outcome—total tramadol consumption within 24 h postoperatively. Based on preliminary data (Δ ≈ 11 mg), a minimum of 53 patients per group was required to achieve a power of 0.80 with an α level of 0.05. The final analysis included 64 patients in the ESPB group and 58 patients in the RLB group, providing over 80% statistical power to detect differences in postoperative tramadol consumption between the two techniques. No correction for multiple comparisons was applied.

Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 22.0 (IBM Corp., Armonk, NY, USA). Continuous variables were presented as mean ± standard deviation (SD), while categorical variables were expressed as numbers and percentages. The normality of continuous data was assessed using the Kolmogorov–Smirnov test. Between-group comparisons were made using the Mann–Whitney U test for continuous variables and the Pearson chi-square test for categorical variables. A p-value of < 0.05 was considered statistically significant.

Results

Patients who underwent elective cesarean section under spinal anesthesia and received bilateral ESPB or RLB for postoperative analgesia were identified. A total of 126 cases were screened; one patient who required reoperation due to postoperative hemorrhage and three patients who received alternative analgesics for post-spinal headache were excluded. The final analysis included 122 patients (RLB group = 58; ESPB group = 64). A detailed flowchart of patient inclusion is presented in Fig. 1. There were no statistically significant differences between the groups in terms of demographic characteristics or surgical/anesthetic parameters (p > 0.05) (Table 1).

Table 1.

Demographic and Clinical Characteristics of Patients in the RLB and ESPB Groups

	Group RLB (n = 58)	Group ESPB (n = 64)	p-value
Age (years)	27.09 ± 3.44	27.02 ± 3.36	0.953
BMI (kg/m2)	32.40 ± 3.72	31.73 ± 3.92	0.291
ASA Physical Status, n (%)			0.966
– II	50 (86.3%)	55 (86%)
– III	8 (13.7%)	9 (14.0%)
Parity	0.76 ± 0.63	0.78 ± 0.60	0.807
Gestational Age (weeks)	38.33 ± 1.19	38.19 ± 0.95	0.463
Comorbidities, n (%)	12 (20.7%)	10 (15.6%)	0.467
Current Medications, n (%)	15 (25.9%)	17 (26.6%)	0.930
Duration of Cesarean Section (min)	72.72 ± 7.61	72.50 ± 7.86	0.653
Duration of Anesthesia (min)	86.14 ± 7.38	85.02 ± 7.27	0.332

Data are expressed as mean ± standard deviation (SD) for normally distributed continuous variables and as n (%) for categorical variables. Comparisons between groups were performed using the Pearson Chi-square test for categorical data and the Mann–Whitney U test for continuous variables. ESPB Erector Spinae Plane Block, RLB Retrolaminar Block, BMI Body Mass Index, ASA American Society of Anesthesiologists

The time to first rescue analgesia was significantly longer in the ESPB group compared to the RLB group (7.86 ± 1.50 vs. 6.78 ± 1.28 h, p < 0.001), indicating a more prolonged analgesic effect with ESPB. In contrast, there was no significant difference between the groups regarding the time to hospital discharge (35.88 ± 5.72 vs. 34.17 ± 5.73 h, p = 0.073). Similarly, ObsQoR-11 T scores were comparable between the groups, showing no statistically significant difference in postoperative recovery quality (85.00 ± 4.76 vs. 84.31 ± 4.11, p = 0.504).

The incidences of postoperative nausea and vomiting (PONV), pruritus, and hypotension were low in both groups, with no statistically significant differences observed (respectively p = 0.885, p = 0.920, and p = 0.246). Although postoperative hypotension occurred slightly more frequently in the ESPB group (7 patients, 10.9%) than in the RLB group (3 patients, 5.2%), this difference was not statistically significant.

Postoperative tramadol consumption was compared between the groups at 1, 6, 12, and 24 h. No tramadol use was observed in either group during the first hour. At 6 h, tramadol consumption was significantly higher in the RLB group compared to the ESPB group (28.79 mg vs. 15.47 mg, p = 0.014). Similarly, at 12 h, the RLB group required more tramadol (75.6 mg vs. 66.09 mg, p = 0.021). By 24 h, total tramadol consumption remained significantly greater in the RLB group than in the ESPB group (141.9 mg vs. 130.94 mg, p = 0.001).

Postoperative pain scores were evaluated at 1, 6, 12, and 24 h in both groups. No significant difference was observed between the RLB and ESPB groups at 1 h (0.69 ± 0.654 vs. 0.75 ± 0.690, p = 0.656). At 6 h, pain scores in the RLB group were significantly higher than those in the ESPB group (3.90 ± 1.238 vs. 3.27 ± 1.238, p = 0.005). Similarly, at 12 h, pain scores in the RLB group remained significantly higher than in the ESPB group (6.17 ± 0.920 vs. 5.17 ± 0.725, p < 0.001). At 24 h, no significant difference was found between the groups (6.41 ± 1.200 vs. 6.11 ± 0.928, p = 0.137).

Discussion

This study is among the limited comparative investigations directly evaluating the analgesic efficacy, opioid consumption, and recovery quality of the RLB and ESPB in CS. Our findings demonstrate that both block techniques provided comparable recovery quality within the first 24 postoperative hours; however, ESPB showed superior analgesic efficacy compared with RLB. In particular, lower tramadol consumption and a longer time to first rescue analgesia suggest that ESPB offers a clinically meaningful advantage in postoperative pain control.

Post-cesarean recovery extends beyond pain control and encompasses multidimensional aspects such as early mobilization, initiation of breastfeeding, maternal–infant bonding, and discharge timing (Kutty et al. 2020). Therefore, contemporary obstetric analgesia approaches emphasize not only pain reduction but also the optimization of functional and emotional recovery through ERAC protocols (Bollag et al. 2021). Fascial plane blocks such as ESPB and RLB are increasingly incorporated into these multimodal protocols as safe, opioid-sparing analgesic options (Lestari et al. 2025).

The analgesic efficacy of ESPB, its ability to reduce opioid requirements, and its contribution to patient satisfaction have been demonstrated in multiple studies (Dostbil et al. 2023; Yilmaz and Erol 2023; Joshi et al. 2024). ESPB has also been reported to provide superior pain control compared with other regional techniques such as the transversus abdominis plane (TAP) and quadratus lumborum blocks (QLB) (Mansour et al. 2025; Zanfini et al. 2023; Priya et al. 2023). However, some studies have reported comparable analgesic effects and recovery scores between ESPB and QLB (Mostafa et al. 2023). These discrepancies may arise from anatomical variations, differences in local anesthetic spread, volume and concentration, or heterogeneity among recovery assessment tools. A recent meta-analysis comparing various fascial plane blocks concluded that while ESPB may offer advantages in opioid reduction, its analgesic efficacy can vary depending on surgical type and technique (Jing et al. 2025). Consistent with these findings, our study suggests that while both techniques yield similar, ESPB demonstrates a trend toward superior analgesic performance, highlighting the importance of individualized block selection.

The ObsQoR-11 T Score, a validated tool that assesses not only pain relief but also mobilization, emotional well-being, breastfeeding success, and maternal–infant interaction (Ozkan et al. 2022). This scale represents one of the few validated instruments capable of capturing the multidimensional biopsychosocial aspects of obstetric recovery. Our findings revealed no significant difference in ObsQoR-11 T total scores at 24 h between ESPB and RLB (p = 0.504). The high scores in both groups indicate that the blocks support not only pain control but also functional and emotional recovery. This aligns with the modern concept of the “pain-to-recovery continuum” in obstetric analgesia. While prior studies often used generic recovery scales such as QoR-15 or QoR-40 and found that ESPB reduced opioid use and improved satisfaction (Mansour et al. 2025; Zanfini et al. 2023; Priya et al. 2023), these tools may not fully reflect the specific physical and emotional dynamics of post-cesarean recovery. Therefore, the use of ObsQoR-11 T, validated in Turkish, represents an important methodological advancement that allows for more sensitive assessment of obstetric recovery (Aydemir et al. 2022).

Although RLB and ESPB are performed at anatomically adjacent levels, the precise mechanisms of local anesthetic spread into deeper tissues and the paravertebral space remain unclear (Ueshima and Otake 2017). RLB, a more recently described technique, offers practical advantages due to its clear ultrasonic landmarks at the laminar level, shorter learning curve, and low complication profile (Onishi et al. 2019). Cadaveric and MRI studies suggest that RLB provides a more localized spread around the dorsal rami compared with ESPB, resulting in a more targeted but narrower block pattern (Adhikary et al. 2018). Conversely, ESPB may achieve a broader somatic and visceral analgesia by affecting both dorsal and ventral rami through anterior spread into the paravertebral and epidural spaces (Adhikary et al. 2018; Zhu et al. 2023). In our study, significantly lower VAS scores at 6 and 12 h, along with reduced total tramadol consumption in the ESPB group, indicate a stronger early postoperative analgesic effect.

Previous studies examining ESPB and RLB have shown heterogeneous results, potentially due to differences in anesthetic spread, ligamentous barriers, and anatomical compartmental capacity. In lumbar spine surgery, ESPB has been associated with lower postoperative pain and opioid consumption without improving Quality of Recovery-40 scores (Kyenshilik et al. 2025), whereas in breast surgery, both blocks demonstrated similar efficacy (Sotome et al. 2021). Likewise, we observed no significant intergroup differences in opioid-related adverse effects (nausea, vomiting, hypotension) or in ObsQoR-11 T scores and discharge times. The incidence of dural puncture headache in our study was slightly higher than commonly reported in the literature, which may be attributable to additional needle passes during spinal anesthesia, patient-related factors, or other procedural variables. Patients who developed dural puncture headache were excluded from the analysis (Table 2).

Table 2.

Postoperative Recovery, Analgesic Efficacy and Adverse Events in the RLB and ESPB Groups

	Group RLB (n = 58)	Group ESPB (n = 64)	p-value
Time to Discharge (hours)	34.17 ± 5.73	35.88 ± 5.72	0.073
Time to First Analgesic Request (hours)	6.78 ± 1.28	7.86 ± 1.50	0.001*
ObsQoR-11 T Score	84.31 ± 4.11	85.00 ± 4.76	0.504
PONV, n (%)	4 (6.9%)	4 (6.3%)	0.885
Pruritus, n (%)	2 (3.4%)	2 (3.1%)	0.920
Hypotension, n (%)	3 (5.2%)	7 (10.9%)	0.246

Data are expressed as mean ± standard deviation (SD) for normally distributed continuous variables and as n (%) for categorical variables. Comparisons between groups were performed using the Pearson Chi-square test for categorical data and the Mann–Whitney U test for continuous variables. ESP Erector Spinae Plane block, RLB Retrolaminar Block, ObsQoR-11 T Obstetric Quality-of-Recovery Score, PONV Postoperative Nausea and Vomiting. *p < 0.05 indicates statistical significance

In our cohort, patients in the RLB group required earlier rescue analgesia and consumed more opioids within the first 24 h, corresponding with higher VAS scores at 6 and 12 h. These findings suggest that their extent of anesthetic spread differs. ESPB likely provides broader somatic and visceral coverage due to ventral diffusion toward the paravertebral and epidural spaces, whereas RLB predominantly affects the dorsal branches, resulting in shorter and less intense analgesia. Therefore, ESPB appears to be a rational choice when extended analgesia and opioid-sparing effects are prioritized in the early postoperative period, whereas RLB offers a technically simpler and hemodynamically stable alternative in settings where procedural efficiency and safety are paramount. These findings support the individualized selection of block techniques within ERAS protocols based on patient characteristics and institutional resources.

Strengths

This study was conducted in a Turkish obstetric population using the culturally validated ObsQoR-11 T scale. Standardized surgical and anesthetic protocols minimized methodological bias, allowing a reliable comparison between ESPB and RLB techniques. As one of the first studies to directly compare these blocks in terms of postoperative recovery quality following cesarean section, it provides valuable preliminary data. Furthermore, the study establishes a methodological foundation for future randomized controlled trials evaluating the feasibility, safety, and clinical trends of both techniques.

Limitations

This study has several limitations. It was conducted at a single center with a limited sample size, which may restrict the generalizability of the findings. The retrospective design, lack of randomization, and reliance on anesthesiologist preference for block selection may have introduced potential selection bias and other methodological constraints. No correction for multiple comparisons was applied and should be considered a limitation of the study. In addition, long-term analgesic outcomes, functional recovery, and breastfeeding success clinically relevant endpoints were not assessed in this study.

Future directions

Future multicenter randomized controlled trials with larger cohorts are warranted to better elucidate efficacy differences between ESPB and RLB. Evaluations of long-term recovery, breastfeeding success, and psychosocial outcomes could yield more comprehensive evidence. Comparative investigations of combination techniques or varying local anesthetic volumes and concentrations may also represent promising research avenues.

Conclusion

This study provides a comparative evaluation of ESPB and RLB in cesarean section. The findings suggest that ESPB may serve as an effective component of multimodal obstetric recovery protocols (ERAS), offering enhanced analgesic efficacy and reduced opioid requirements. Meanwhile, RLB remains a reliable alternative, with technical simplicity and hemodynamic stability that align well with ERAS principles.

Authors’ contributions

SB: Conceptualization, Methodology, Software, Data curation, Writing – Original draft preparation, Validation, Writing – Reviewing and Editing. CŞ: Conceptualization, Visualization, Investigation, Supervision, Software. All authors approved the final version of the manuscript to be published.

Funding

No external funding was received for this study.

Data availability

The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

The study was approved by the local ethics committee (Decision No: 2025/16–03) and conducted in accordance with the Declaration of Helsinki. Owing to the retrospective design and use of anonymized data, the requirement for individual informed consent was waived. The protocol is registered at ClinicalTrials.gov (NCT07181902).

Consent for publication

Not applicable. No individual person’s data (images or identifiable information) are included.

Competing interests

The authors declare no competing interests.