TITLE:

ROLE OF PARASTERNAL INTERCOSTAL PLANE BLOCK USING ROPIVACAINE IN ATTENUATING HEMODYNAMIC FLUCTUATIONS AT THE TIME OF STERNOTOMY IN PATIENTS UNDERGOING ELECTIVE CARDIAC SURGERY

INTRODUCTION

Elective cardiac surgery is a complex and high-risk procedure that often requires sternotomy (surgical incision of the sternum), which involves dividing the breastbone to gain access to the heart [1]. Sternotomy may be associated with significant hemodynamic fluctuations, including changes in heart rate, blood pressure, and systemic vascular resistance [2]. These fluctuations can result in increased perioperative stress, myocardial oxygen demand, and adverse outcomes in patients undergoing cardiac surgery [3]. Managing these hemodynamic fluctuations is crucial in ensuring successful outcomes in cardiac surgery. Therefore, effective perioperative pain management techniques are essential to minimize hemodynamic fluctuations and improve patient outcomes.

One potential approach to mitigate hemodynamic fluctuations during sternotomy is the use of regional anesthesia techniques, such as the parasternal intercostal plane block with ropivacaine. Ropivacaine is a local anesthetic and cardio-stable [4]. Parasternal intercostal plane block (PIPB) is a regional anesthesia technique that involves the administration of a local anesthetic, such as Ropivacaine, into the parasternal intercostal plane, which is located between the ribs and the sternum [5]. PIPB has been shown to provide effective analgesia and reduce opioid consumption in patients undergoing cardiac surgery [6].

The primary objective of this study is to investigate the role of PIPB with Ropivacaine in attenuating hemodynamic fluctuations at the time of sternotomy in patients undergoing elective cardiac surgery. The study aims to evaluate the effect of PIPB on hemodynamic parameters, such as heart rate, blood pressure, and systemic vascular resistance, during sternotomy, and compare it with standard pain management techniques.

The findings of this study may provide valuable insights into the potential benefits of the parasternal intercostal plane block (PIPB) with ropivacaine in cardiac surgery, including its potential to improve patient outcomes and enhance perioperative care. The results of this study may also contribute to the existing body of knowledge on regional anesthesia techniques for elective cardiac surgery and help inform clinical practice in managing hemodynamic fluctuations during sternotomy.

AIM AND OBJECTIVES

AIM

The aim of the study is to investigate the role of the parasternal intercostal plane block using ropivacaine on hemodynamic fluctuations during sternotomy in patients undergoing elective cardiac surgery.

OBJECTIVES:

Primary Objectives:

1.      To investigate the role of parasternal intercostal plane block using Ropivacaine in attenuating hemodynamic fluctuations during sternotomy in patients undergoing elective cardiac surgery.

Secondary Objectives:

1.      Percentage reduction in total opioid used in surgery.

2.      Fast tracking

METHODOLOGY

Study setting: The study will be conducted at the Department of Anesthesiology, King George’s Medical University, Lucknow, Uttar Pradesh.

Study Design: This study will be a prospective, randomized case-controlled trial. The study will follow a parallel-group design with two arms: an intervention group receiving parasternal intercostal plane block with ropivacaine and a control group receiving standard care without the block.

Study duration: 12 months

Ethical Clearance: The study will be conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. Ethical approval will be obtained from the institutional ethics committee, KGMU, before conducting the study. Informed consent will be obtained from all participants before enrollment, and they will be assured of confidentiality and the right to withdraw from the study at any time without any consequences.

INCLUSION AND EXCLUSION CRITERIA:

Inclusion Criteria:

1.      Patients ≥18 years and ≤60 years posted for elective cardiac surgery.

Exclusion Criteria:

Patients with

-          Patient giving history of past cardiac surgery using sternotomy or needing end of life care support.

-          Coronary Artery Disease (CABG will be excluded).

-          Uncontrolled Diabetes Mellitus type – 2 (HbA1C ≥9).

-          Chronic Kidney Disease.

-          Documented Liver dysfunction (CHILD’s Class B, C)

Sample Size Calculation:

Sample Size at 90% Power:
Sample size is calculated on the basis of variation in the NRS score in the study the groups using the formula.

Where s₁ = 3.0, The half IQR of NRS score in control group

s₂ = 2.25,  The half IQR of NRS score in experimental group

(Ref. Pascarella G, Costa F, Nonnis G, Strumia A, Sarubbi D, Schiavoni L, Di Pumpo A, Mortini L, Grande S, Attanasio A, Gadotti G, De Cassai A, Mattei A, Nenna A, Chello M, Cataldo R, Agrò FE, Carassiti M. Ultrasound Guided Parasternal Block for Attenuating Hemodynamic Fluctuations in Cardiac Surgery: A Prospective Study. J Clin Med. 2023 Mar 6;12(5):2060.)

d = min(s₁, s₂), the difference considered to be clinically significant

k = 1.25 the design effect for considering confounding effect of several factors

type I error α = 5% corresponding to 95% confidence level

type II error β = 10% for detecting results with 90% power of study

So the required sample size

n = 45 each group

Statistical Analysis:

SPSS latest available version and MS Excel will be used for statistical analysis of the data. Continuous variables conforming to a normal distribution will be expressed as mean ± standard deviation. Counting data will be expressed as number and percentages. The unpaired t test or non-parametric equivalent will be used for inter-group analysis. The χ2 test will used to compare the proportion data between the groups. Other appropriate statistical tests will be used. In all of the statistical analyses, P < 0.05 will be considered to be statistically significant.

Randomization: Eligible participants will be randomized into either the intervention or control group using alternate patients in a 1:1 ratio.

Intervention: The intervention group will receive a parasternal intercostal plane block with 0.5% ropivacaine under ultrasound guidance before sternotomy. The block will be performed by an experienced anesthesiologist following a standardized technique. The control group will receive standard care without the block.

Data Collection: Baseline demographic data, including age, gender, body mass index, comorbidities and physical status will be recorded at the time of enrollment of the participant. Hemodynamic parameters, including heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and central venous pressure, will be recorded at baseline (pre-induction), intraoperatively (at sternotomy, after bypass initiation, at sternum closure), and postoperatively (at 1 hour, 6 hours, and 24 hours after surgery).

OUTCOME MEASURES:

Primary outcome:

The primary outcome measure will be the magnitude of hemodynamic fluctuations, defined as the percentage change in mean arterial pressure from baseline to intraoperative measurements.

Secondary outcome:

Secondary outcome measures will include changes in heart rate, systolic blood pressure, diastolic blood pressure, central venous pressure, duration of mechanical ventilation, length of intensive care unit (ICU) stay, postoperative pain scores, and adverse events.

REVIEW OF LITERATURE:

A randomized study by Scott NB, et.al., 2001., investigated the benefits of thoracic epidural anesthesia and analgesia in patients undergoing coronary artery bypass grafting (CABG). The authors found that thoracic epidural anesthesia and analgesia resulted in attenuated hemodynamic responses during sternotomy, indicating that regional anesthesia techniques can have a beneficial effect on hemodynamic stability during cardiac surgery [7].

Liu SS, et.al., 2004; conducted meta-analysis that provides evidence that perioperative central neuraxial analgesia can reduce hemodynamic fluctuations during cardiac surgery, which may support the potential benefits of regional analgesic techniques, such as parasternal intercostal plane block, in attenuating hemodynamic fluctuations during sternotomy[8].

Haas T, et.al., 2005;  compared thoracic epidural anesthesia combined with general anesthesia versus general anesthesia alone in patients undergoing cardiac surgery. The authors found that the combination of thoracic epidural anesthesia and general anesthesia resulted in reduced hemodynamic fluctuations, including attenuated blood pressure and heart rate changes, during surgery, indicating that regional anesthesia techniques can help stabilize hemodynamics during cardiac surgery [9].

Marret E,. et.al., 2007; did a meta-analysis to compare epidural analgesia with parenteral opioid analgesia in patients undergoing colorectal surgery. The results showed that epidural analgesia was associated with better pain control and reduced stress response, including attenuated hemodynamic fluctuations, compared to parenteral opioid analgesia. This suggests that regional anesthesia techniques, such as epidural analgesia, may have a beneficial effect on hemodynamic stability during surgery [10].

This review by article; Blanco, R., & McDonnell, J. G. (2011); discusses various pain management strategies after sternotomy, including the use of parasternal intercostal plane blocks with local anesthetics. It highlights the potential benefits of parasternal intercostal plane blocks in reducing postoperative pain and opioid consumption, which could indirectly impact hemodynamic stability during sternotomy [11].

Royse, C. F., et.al., 2011; discussed the importance of postoperative recovery after cardiac surgery, including the management of pain and hemodynamic stability. It emphasizes the need for effective pain management strategies to achieve optimal postoperative recovery. Parasternal intercostal plane blocks with ropivacaine could be a potential strategy to achieve this goal [12].

Hamilton, D. L., & Manickam, B. (2013); reviewed the role of intercostal nerve blocks in pain relief after thoracotomy, including sternotomy. It discusses the potential benefits of parasternal intercostal plane blocks with local anesthetics in reducing postoperative pain and the potential impact on hemodynamic stability during sternotomy [13].

Bignami E, et.al., 2016 conducted a randomized controlled trial that evaluated the efficacy of parasternal intercostal plane block with ropivacaine for postoperative analgesia in cardiac surgery. The study found that parasternal intercostal plane block with ropivacaine resulted in reduced opioid consumption, decreased pain scores, and improved patient satisfaction, suggesting that this technique may be effective in providing analgesia in cardiac surgery patients [14].

Kundra, P., et.al., 2019; has also did a randomized controlled trial compared parasternal block with pectoral nerve block for postoperative pain relief after modified radical mastectomy. It demonstrated the efficacy of parasternal block in reducing pain scores and opioid consumption. These findings suggest the potential benefits of parasternal intercostal plane blocks with ropivacaine in attenuating hemodynamic fluctuations during sternotomy in cardiac surgery patients [15].

Liu J, et.al., 2020; has conducted a meta-analysis of randomized controlled trials evaluated the efficacy of parasternal intercostal nerve block for postoperative pain management after cardiac surgery. The analysis showed that parasternal intercostal nerve block was associated with reduced pain scores, decreased opioid consumption, and improved patient satisfaction, indicating that this technique may be effective in managing postoperative pain in cardiac surgery patients [16].

Patil SP & Patel RD, 2021; has published a systematic review and meta-analysis that provides an overview of the role of parasternal intercostal plane block in attenuating hemodynamic fluctuations during sternotomy in cardiac surgery. The study concludes that parasternal intercostal plane block with ropivacaine is effective in reducing the hemodynamic fluctuations associated with sternotomy [17].

Urits I, et al., 2021; discuss the pharmacology and clinical applications of ropivacaine for acute pain management. It provides an in-depth understanding of the properties and clinical use of ropivacaine, including its efficacy and safety in various surgical settings, which can support the use of ropivacaine for a parasternal intercostal plane block in cardiac surgery. [18]

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8.      Liu SS, Block BM, Wu CL. Effects of perioperative central neuraxial analgesia on outcome after coronary artery bypass surgery: a meta-analysis. Anesthesiology. 2004;101(1):153-161. doi:10.1097/00000542-200407000-00025

9.      Haas T, Friesdorf W, Jacobi KE, Goertz AW. Thoracic epidural anesthesia combined with general anesthesia versus general anesthesia alone for cardiac surgery: effects on early and late outcomes. Anesth Analg.2005;101(5):1183-1191.doi:10.1213/01.ANE.0000184082.74972.CB

10.  Marret E, Remy C, Bonnet F, et al. Meta-analysis of epidural analgesia versus parenteral opioid analgesia after colorectal surgery. Br J Surg. 2007;94(6):665-673. doi:10.1002/bjs.5756

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12.  Royse, C. F., Newman, S., Chung, F., Stygall, J., McKay, R. E., Boldt, J.,... & Cheng, D. (2011). Development and feasibility of a scale to assess postoperative recovery: the post-operative quality recovery scale. Anesthesiology, 114(4), 892-906. doi: 10.1097/ALN.0b013e318210c99c

13.  Hamilton, D. L., & Manickam, B. (2013). Intercostal nerve blocks for pain relief after thoracotomy. Current Opinion in Anaesthesiology, 26(1), 40-44. doi: 10.1097/ACO.0b013e32835a1b1e

14.  Bignami E, Di Dedda U, De Luca M, et al. Parasternal Intercostal Plane Block With Ropivacaine for Postoperative Analgesia in Cardiac Surgery: A Prospective, Randomized, Double-Blind, Placebo-Controlled Trial. J Cardiothorac Vasc Anesth. 2016;30(1):48-54. doi:10.1053/j.jvca.2015.09.015

15.  Kundra, P., Luthra, A., Kannan, U., & Arora, A. (2019). Comparison of parasternal block and pectoral nerve block for postoperative pain relief after modified radical mastectomy: A randomized controlled trial. Indian Journal of Pain, 33(3), 150-154. doi: 10.4103/ijpn.ijpn_56_19

16.  Liu J, Yuan M, Chen Q, Zhang L. Efficacy of parasternal intercostal nerve block for postoperative pain management after cardiac surgery: a meta-analysis of randomized controlled trials. J Cardiothorac Surg. 2020;15(1):64. doi:10.1186/s13019-020-01112-7

17.  Patil SP, Patel RD, Parasternal intercostal plane block for cardiac surgery: A systematic review and meta-analysis. J Cardiothorac Vasc Anesth. 2021;35(6):1777-1790. doi:10.1053/j.jvca.2020.10.068

18. Urits I, Burshtein A, Sharma M, et al. Recent Advances in the Use of Ropivacaine for Acute Pain Management. Pain Ther. 2021;10(1):117-138. doi:10.1007/s40122-020-00217-9