European Journal of Cardiovascular Medicine

Coronary artery bypass graft (CABG) surgery is a critical intervention for advanced coronary artery disease, offering substantial improvements in survival rates and quality of life. By restoring blood flow to the heart, CABG alleviates severe symptoms such as chest pain and reduces the likelihood of life-threatening cardiac events ^[1]. However, the procedure is often associated with significant postoperative pain, which, if poorly managed, can impede recovery. This pain can cause breathing difficulties, elevate physiological stress, delay wound healing, and lengthen hospital stays. Managing this pain effectively is essential to optimize recovery, improve patient outcomes, and enhance overall well-being.

Historically, systemic analgesics, particularly opioids, have been the cornerstone of postoperative pain management for CABG. While effective in relieving pain, opioids are associated with numerous side effects, including sedation, nausea, constipation, and a potential risk of dependency. These drawbacks have led to growing interest in alternative approaches, particularly regional anesthesia techniques, which aim to provide localized pain relief while minimizing reliance on opioids. Among the most promising options are the Erector Spinae Plane (ESP) block and the Serratus Anterior Plane (SAP) block ^[2]. Both techniques involve injecting local anesthetics into specific fascial planes to achieve targeted and prolonged analgesia, making them important components of a multimodal approach to pain management.

The ESP block, introduced in 2016, is performed by injecting a local anesthetic deep to the erector spinae muscle. This technique targets both the dorsal and ventral branches of spinal nerves, providing broad dermatomal coverage. Its simplicity, safety profile, and versatility have made it a popular choice for managing postoperative pain in various types of surgeries, including thoracic and abdominal procedures. For CABG patients, the ESP block is particularly advantageous as it can address both visceral and somatic pain associated with the surgery ^[3]. Furthermore, its ability to provide bilateral pain relief through a unilateral approach is a key benefit. Compared to traditional methods such as epidural or paravertebral blocks, the ESP block carries a lower risk of complications and is well-suited to the unique pain patterns seen in CABG patients, such as pain from sternotomy or chest drains ^[4].

In contrast, the SAP block is performed by injecting local anesthetics into the fascial plane near the serratus anterior muscle, targeting the thoracic intercostal nerves and the long thoracic nerve. Initially developed for breast and thoracic surgeries, the SAP block has shown considerable promise in managing postoperative pain for cardiac surgeries. It is particularly effective for addressing lateral chest wall pain, a common issue in CABG patients who undergo sternotomies or thoracotomies ^[5]. The SAP block’s superficial location and ease of administration under ultrasound guidance further enhance its utility, making it an accessible option for clinicians. Its targeted analgesic effect is especially beneficial for patients experiencing localized discomfort, enabling them to engage in essential postoperative activities such as deep breathing exercises, which are critical for preventing respiratory complications 5r^[6].

The choice between the ESP and SAP blocks for postoperative pain management in CABG depends on several factors, including the primary pain source, the surgical approach, and individual patient characteristics. The ESP block’s ability to provide broad dermatomal coverage and deeper analgesic effects makes it a suitable choice for patients with more extensive or complex pain patterns ^[7]. This technique effectively addresses pain originating from sternotomy, chest drains, and other surgical interventions, offering comprehensive relief. Conversely, the SAP block is particularly useful for managing localized lateral chest wall pain, thanks to its targeted approach. Its straightforward administration and minimal invasiveness also make it a favorable option in certain clinical scenarios ^[8].

Both techniques benefit significantly from the use of ultrasound guidance, which enhances precision and reduces the risk of complications. However, variations in patient anatomy, surgical conditions, and technical challenges can influence the relative effectiveness of these methods ^[9]. While both ESP and SAP blocks have been shown to reduce opioid consumption and improve pain scores in the immediate postoperative period, direct comparative studies remain limited. Further research is needed to fully understand their respective strengths and limitations, particularly regarding the duration of pain relief, potential complications, and specific technical challenges ^[10].

Existing evidence underscores the significant benefits of both ESP and SAP blocks in CABG surgery. They provide effective pain relief, reduce reliance on opioids, and enhance postoperative recovery by supporting critical functions such as early mobilization and improved respiratory function ^[11]. However, there is still much to learn about the long-term outcomes and optimal applications of these techniques. Future studies should aim to evaluate the comparative effectiveness of ESP and SAP blocks in various clinical contexts, considering factors such as patient satisfaction, functional recovery, and overall cost-effectiveness. Additionally, investigating their integration into multimodal pain management protocols could provide valuable insights into improving patient care ^[12].

The increasing use of regional anesthesia techniques like the Erector Spinae Plane (ESP) and Serratus Anterior Plane (SAP) blocks highlights a shift toward personalized pain management in cardiac surgery. Customizing pain relief strategies to address individual factors, such as pain location, intensity, anatomy, and comorbidities, enables better outcomes and a smoother surgical recovery. As key components of multimodal pain management, these blocks provide targeted and effective analgesia while reducing reliance on systemic opioids and their associated risks ^[13].

The ESP and SAP blocks are particularly valuable in managing postoperative pain in CABG patients due to their minimally invasive nature, safety, and efficacy. Each technique offers distinct strengths, enhancing pain control and supporting faster recovery. With ongoing research into their unique advantages and applications, these methods hold great promise for transforming postoperative care, improving patient experiences, and significantly enhancing quality of life after cardiac surgery ^[14].

This study aims to compare the reduction in opioid use and evaluate the quality of recovery and morbidity between Erector Spinae Plane (ESP) block and Serratus Anterior Plane (SAP) block in patients undergoing CABG. The primary objective is to assess intraoperative and postoperative opioid requirements in patients receiving ESP versus SAP blocks. Secondary objectives include evaluating postoperative complications using the Comprehensive Complication Index calculator and assessing the quality of recovery based on the QoR-15 Scale in patients managed with ESP and SAP blocks.

This prospective, randomized observational study will compare the effects of ESP and SAP blocks in CABG patients over 4 to 8 months. Ethical approval has been obtained to conduct this study. Each group (45 patients, total 90) will receive 20ml of 0.25% Levobupivacaine bilaterally. Intraoperative and postoperative opioid requirements will be recorded based on hemodynamic parameters. Quality of recovery will be assessed at 24 hours postoperatively using the QoR-15 scale. Inclusion criteria include elective cardiac surgeries under general anesthesia, age 18–80, and ASA grades 1–3. Exclusion criteria include refusal of consent, infection at the block site, contraindications to regional anesthesia, opiate abuse, chronic pain, or cognitive dysfunction.

Table 1: Demographic comparison between the ESP and SAP groups

Figure 1: comparison between the ESP and SAP groups

The demographic and surgical data reveal that the ESP group has a slightly higher average age (56.3 years) than the SAP group (52.1 years), while both groups have a male majority, with more females in the SAP group (32.26% vs. 22.41%). BMI is similar (27.09 vs. 26.98 kg/m²), and surgery durations are comparable (4.16 vs. 4.35 hours).

Table 2: Comparison of the adverse events between patients receiving Erector Spinae Plane (ESP) and Serratus Anterior Plane (SAP) blocks

Adverse events were comparable between ESP and SAP blocks, with arrhythmias slightly higher in the ESP group (10.35% vs. 8.07%) and delayed extubation more common in the SAP group (11.29% vs. 3.45%). Infections occurred more frequently in the ESP group (12.07% vs. 6.45%), while both groups showed a similar proportion of patients with no adverse events (74.14% vs. 74.19%).

Table 3: Comparison of the fentanyl consumption between Esp and SAP group

Figure 2: Comparison of the fentanyl consumption between Esp and SAP group

Fentanyl consumption was lower in the ESP group (mean 295.8 mcg, SD 24.74) compared to the SAP group (mean 384.2 mcg, SD 17.36), suggesting better analgesic efficacy with the ESP block. The tighter standard deviation in the SAP group indicates more consistent fentanyl usage within this cohort, despite higher overall requirements.

Table 4: Comparison of the QoR-24 (Quality of Recovery) scores between the Erector Spinae Plane (ESP) and Serratus Anterior Plane (SAP) groups

The table compares the Quality of Recovery (QoR-24) scores between two pain management techniques: the Erector Spinae Plane (ESP) and the Serratus Anterior Plane (SAP). The ESP group has a higher total score (297) compared to the SAP group (256), indicating better overall recovery. The average QoR-24 score is also higher in the ESP group (4.79) than in the SAP group (4.41), suggesting a more favorable patient experience. However, the standard deviation (SD) is higher in the SAP group (2.95) than in the ESP group (2.46), indicating more variability in recovery scores among SAP patients. These findings suggest that ESP may provide more consistent and superior recovery outcomes compared to SAP.

Table 5: Length of Hospital stay comparison between ESP and SAP

Hospital stays were similar between ESP and SAP blocks, with the ESP group averaging slightly fewer days (6.52 vs. 6.89) and similar standard deviations (1.56 vs. 1.55). Minimum stays were 4 days for both, while maximum stays were 9 days (ESP) and 10 days (SAP), suggesting comparable recovery times but a marginal advantage for the ESP group.

Coronary artery bypass graft (CABG) surgery is vital for advanced coronary artery disease, improving survival and quality of life. Effective postoperative pain management is crucial to recovery, as poor control can delay healing and increase stress. Regional anesthesia techniques like Erector Spinae Plane (ESP) and Serratus Anterior Plane (SAP) blocks are promising alternatives to opioids, offering targeted pain relief with fewer side effects. This study compares opioid reduction, complications, and recovery quality between ESP and SAP blocks using the QoR-15 scale and complication indices ^[15].

Our findings correlate with the analgesic efficacy of ESPB and SAPB in thoracic surgeries, focusing on pain management while analyzing demographics. Similar to our observations, Muhammad QU et al. (2024) reported comparable age, gender distribution, BMI, and surgery durations in patients receiving bilateral thoracic ESPB during CABG, highlighting a male majority and similar BMI between groups. Demir ZA et al. (2024) also supported these trends, noting demographic parallels with our study, including a slightly higher average age in the ESP group and a male predominance in both. These studies validate our findings of demographic similarities, such as BMI and surgery duration consistency, while emphasizing the relevance of ESP and SAP blocks in enhancing analgesic outcomes in CABG patients ^[16,17].

Our findings on adverse events with ESP and SAP blocks align with the studies by Nooli NP et al. (2024) and Misra S et al. (2021), emphasizing the need for comprehensive evaluations of safety profiles in cardiac surgeries. Nooli NP et al. (2024) highlighted the efficacy of fascial plane blocks like ESPB in cardiac surgeries, noting comparable adverse events but limited data on arrhythmias, delayed extubation, and infections. Similarly, Misra S et al. (2021) reviewed ESPB and other techniques, focusing on analgesic efficacy and recovery while identifying gaps in reporting specific adverse outcomes. Our findings address these gaps, reporting slightly higher arrhythmias and infections in the ESP group, and more delayed extubation in the ESP group, supporting further investigation ^[18,19].

Our findings of lower fentanyl consumption in the ESP group (mean 295.8 mcg, SD 24.74) compared to the SAP group (mean 384.2 mcg, SD 17.36) align with studies by Ekinci M et al. (2020) and Abd ELaziz MM et al. (2024). Both studies demonstrated that ESPB provides superior analgesic efficacy in video-assisted thoracic surgery (VATS), with significantly lower intraoperative and postoperative opioid consumption, prolonged analgesic effects, and better pain control (lower static and dynamic VAS scores). These results support the enhanced analgesic efficacy of ESPB, consistent with our observations of reduced fentanyl requirements in the ESP group ^[20,21].

Our findings, showing higher QoR-24 scores in the ESP and SAP group (297 vs. 256) and more consistent recovery (SD 2.46 vs. 2.95), suggest superior postoperative recovery with the ESP block, differing from studies by Finnerty DT et al. (2020) and Abid S et al. (2021). These studies, focused on thoracic surgery, reported higher QoR-15 scores with ESP blocks, indicating better recovery quality. This contrast highlights the potential variability in recovery outcomes based on surgical context, as our study on coronary artery bypass graft surgery suggests the SAP block may offer advantages. Context-specific evaluations remain crucial for assessing recovery quality [22,23].

Our findings, showing similar hospital stays between ESP and SAP blocks with a slight advantage for the ESP group (6.52 vs. 6.89 days), align with studies by Wu W et al. (2023) and Muhammad QU et al. (2024). Wu W et al. analyzed randomized controlled trials in thoracic surgeries, reporting no significant difference in hospital stay durations between ESPB and SAPB groups, consistent with our results. Similarly, Muhammad QU et al. observed comparable hospital stays in patients undergoing uniportal thoracoscopic lobectomy, despite focusing primarily on pain and opioid use. These studies confirm similar recovery times with minor advantages for ESPB ^[24,25].

In this study, Erector Spinae Plane (ESP) and Serratus Anterior Plane (SAP) blocks were compared for postoperative pain management in CABG patients. The ESP block demonstrated superior analgesic efficacy with reduced fentanyl consumption, while the SAP block provided better quality of recovery. Both techniques showed comparable adverse event profiles and hospital stay durations, with minor variations favoring ESP for safety and SAP for recovery consistency. These findings highlight the complementary roles of ESP and SAP blocks in CABG, emphasizing the importance of individualized approaches to optimize pain relief and recovery. Further research is warranted to refine their applications.

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