Serratus and Parasternal Infrapectoral Block for Breast Reduction Surgery.

Serratus and Parasternal Infrapectoral Block for Breast Reduction Surgery. A Randomized Controlled Double Blinded Study to Measure Impact on Time to Hospital Discharge in an Outpatient Setting.

Effective pain control is important following breast surgery as it improves quality of recovery, decreases the risk of chronic pain development and reduction of overall health care cost . Current strategies of pain management for breast surgery include use of opioid medication or addition of regional anesthesia along with general anesthesia. Serratus block and parasternal infrapectoral blocks are newly developed fascial plane blocks that are technically easy to perform, effective and safe based on our daily clinical practice and published evidence. We are comparing the addition of serratus and parasternal infrapectoral nerve block with general anesthesia to a combination of placebo and general anesthesia for breast reduction surgery. We propose that this would result in an improved efficiency resulting in early hospital discharge and improve quality of patient care, following breast reduction surgery .

Title: Serratus and Parasternal Infrapectoral block for breast reduction surgery. A randomized controlled double blinded study to measure impact on time to hospital discharge in an outpatient setting. Introduction 1. Postoperative pain. The prevalence of severe acute postoperative pain after breast surgery is almost 60%. Inadequate pain control in the postoperative period can lead to acute physiological and psychological responses that negatively affect patient outcome and increase health care costs along with increased incidence of chronic pain. Effective peri-operative pain management, reduces the frequency of developing chronic pain in these patient cohort, improves the quality of their recovery, provides early hospital discharge thus reduction in over all health care cost. Several analgesic regimes are in use, which vary from regional analgesia techniques to opioid based analgesia. To offer an efficacious perioperative patient care, a multimodal analgesic technique in combination with regional anesthesia will be of benefit in providing excellent pain control and improve quality of recovery. Innervation of the breast and axilla and regional anesthesia. The skin and underlying subcutaneous tissue of the chest wall and the breast is innervated by cutaneous branches of the intercostal nerves. Anterior cutaneous branch of lateral cutaneous nerve ( sensory supply the lateral half of breast) and lateral branch of medial cutaneous nerve ( sensory supply of medial half of breast)originating from T2-T6 intercostal nerves are mainly responsible sensory supply of the breast tissue. The lateral branch innervates the medial half of the breast. Innervation of the axilla and the medial aspect of the proximal arm is provided by the intercostobrachial nerve which represents the lateral cutaneous branch of the intercostal nerve arising from the second thoracic spinal nerve (9-12). These intercostal nerves can be blocked within the plane between the rib, external intercostal muscle and the serratus muscle in the anterolateral chest wall. In the antero-medial chest wall( parasternal area) these intercostal nerves can be blocked between the rib, external intercostal muscle and pectoralis major muscle. Current analgesic strategies for breast surgery and their limitations. Regional analgesic techniques confer numerous advantages over standard parenteral opioid therapy such as superior pain relief, reduced opioid consumption with a reduction in opioid-related side effects, shorter time to meet post anesthesia care unit (PACU) discharge criteria and a reduced incidence of chronic pain syndromes . Paravertebral analgesia is highly effective for breast surgery analgesia . Paravertebral nerve blocks are achieved by injecting a local anesthetic into the paravertebral space. This is an anatomical compartment close to the vertebral bodies and in continuity with neighbouring vertebral levels containing the spinal nerves. However, there are some disadvantages related to paravertebral blockade which strongly limit its popularity among anesthesiologists: first, the sensory distribution of a single-shot paravertebral blockade is highly variable and unpredictable . Therefore, multiple injections are required to achieve a more reliable analgesic spread which may reduce patient acceptance. Next, in a significant number of cases, local anesthetics injected into the paravertebral space reach the epidural space which may result in an epidural blockade with potential hemodynamic consequences such as hypotension. Third, even in experienced hands, there is a failure rate of paravertebral blocks of up to 13% . Fourth, paravertebral blockade is associated with potentially disastrous risks such total spinal anesthesia, pleural puncture or pneumothorax . Finally, an increasing number of breast surgeries is performed on a day case surgery basis where accepting the mentioned risks is particularly not desirable. Therefore, regional analgesic techniques that are at least equally effective, reliable and entail significantly less serious risks compared to paravertebral blockade have to be established for breast surgery. Interfascial block techniques have become popular by the use of ultrasound in regional anesthesia. These techniques rely on the spread of the local anesthetic that has been injected into a neuro-fascial plane adjacent to a muscle or between two readily-discernable muscle layers. The local anesthetic will distribute within this plane and thereby eventually reach the nerves that are known to travel along or cross this plane. There are several potential advantages of interfascial blocks: most importantly, they are technically easy to perform. Rather than directly targeting the nerves which may require a considerable level of experience depending on the localization of the nerves to be blocked and the surrounding structures, interfascial plane blocks simply require deposition of the local anesthetic in a fascial plane that is often easy to identify. At the same time, the avoidance of directing the block needle in close proximity to the nerves increases the safety of these techniques. In addition, an interfascial plane block usually involves a single injection whereas many other nerve blocks require several redirections of the block needle or even multiple punctures, as it is the case with paravertebral blocks. Finally, interfascial blocks are performed at more superficial sites of the body and not close to neuraxial structures or vital organs such as the lung. With this rationale in mind and based on a good knowledge of the anatomy and innervation of the thoracic wall, several fascial plane blocks have recently been described. Serratus Anterior Plane block for breast surgery Serratus Plane Block is a newer fascial plane described by Blanco in 2013. Local anesthetic is injected below the serratus anterior muscle (interfascial plane between the serratus anterior and the external intercostal muscles and ribs) to target the cutaneous branches of the intercostal nerves as described above. Our recently completed anatomical study clearly documented that a single injection at the midaxillary line is not adequate to provide analgesia for the whole breast at it covers only the antero-lateral part without much spread to the antero-medial aspect of the chest wall.Therefore we decided to add another injection at parasternal level below the pectoralis major muscle to achieve a complete sensory of the breast tissue. To date, there exists no randomized controlled trial (RCT) investigating the efficacy of the serratus block and parasterenal infrapectoral block as an analgesic efficacy, quality of recovery, hospital discharge in patients undergoing breast surgery. Questions and Hypothesis Primary Question Does the addition of serratus block and parasternal infrapectoral nerve block to general anesthesia result in an improved perioperative patient care resulting in early hospital discharge following breast reduction surgery procedure compared to patient undergoing general anesthesia with sham block ? Secondary Questions Does the addition of these blocks to general anesthesia result in other benefits such as: I. less post operative pain. II. less intraoperative opioid consumption. III. less postoperative opioid consumption. IV. less incidence of opioid-related side effects such as nausea, vomitus and pruritus. V. greater patient satisfaction with their pain relief improved. VI. greater quality of recovery after anesthesia. VII. shorter phase I (PACU) and phase II (surgical day care, SDC) recovery times). Project design, methodology and analysis Trial Design This will be a prospective, double-blinded, randomized and controlled trial conducted at Victoria Hospital, London, Ontario. The study will enroll 120 patients undergoing bilateral breast reduction surgery under general anesthesia. After obtaining written informed consent from eligible patients, study participants will be randomly assigned to one of two groups: Study Group: Patients will receive preoperative ultrasound-guided bilateral serratus block with 20 mls of 0.2% ropivacaine on each injections at anterior axillary line at 4th rib and bilateral ultrasound guided parasternal infrapectoral block at the level of 4th with 20mls of 0.2% ropivacaine on each injection, 15 minutes prior to receiving general anesthesia for the surgery. Control group: Before general anesthesia, patients will receive a preoperative "sham injection" of similar volume of 0.9% saline instead of ropivacaine for bilateral serratus and parasternal infrapectoral nerve block. Randomization and Blinding Patients will be randomized to one of two groups by a computer-generated sequence. Investigators and participants will both be blinded to patient assignment at the time of randomization as well as throughout treatment and assessment. Randomization information will be kept in sealed individual envelopes that are opaque to light and sequentially numbered. Each envelope will only be opened after informed consent is given, and immediately prior to the commencement of the block procedure. The individual who generates the randomization schedule will not have contact with study patients. Patients who are randomized to the control group will receive equivalent volume of normal saline solutions for the bilateral blocks procedure in contrast to the patients in the intervention group who receive four injections of 20mls of 0.2% Ropivaciane for each injection. This is meant to maintain patient and investigator blinding. The anesthetist(s) performing the block will be blinded to the intervention along with the anesthetists performing the general anesthesia and the surgical team. Importantly, the intraoperative and postoperative opioids will be administered by anesthetists and nurses, respectively, who are blinded to group allocation. Furthermore, the research coordinator collecting all outcome data will also be blinded. Interventions 4.1. Preoperative Management Standard monitoring (ECG, blood pressure and oxygen saturation monitoring) will be applied, an intravenous access will be established and patients will receive midazolam 1-2 mg IV for anxiolysis as required. They will be positioned supine for the block performance. The skin overlying the chest wall will be disinfected using a chlorhexidine solution and a high-frequency linear ultrasound transducer (6-13 MHz, Sonosite M-Turbo) will be covered with a sterile plastic sheath. The block will be performed under strictly aseptic conditions by a staff regional anesthetist, by two regional anesthesiologists specialized to perform this nerve block. 4.2. Study Group (Serratus Block and Parasternal Infrapectoral with 0.2% Ropivaciane) Serratus Block The ultrasound transducer will be placed in a caudal to cranial orientation on the anterior axillary line at the level of the 4th rib. The target fascial plane between the serratus anterior (superficial) and the external intercostal (deep) muscles and the rib will be identified and the path of the block needle will be determined. After local anesthetic infiltration of the skin with 1% lidocaine, a 80 mm 22G block needle will be inserted at the caudal aspect of the ultrasound probe and advanced in-plane to target the fascial plane directly below the serratus muscle. Once the tip is verified in the correct position, 20 mls of 0.2% ropivacaine will be injected into the plane slowly in 5 ml aliquots under frequent aspiration and correct spread in the interfascial plane will be observed. After injection, patients will be closely monitored until they will be brought to the OR. Parasternal Infrapectoral Block The ultrasound transducer will be placed in a caudal to cranial orientation on the parasternal area in the anterior chest wall at the level of the 4th intercostal space. The target fascial plane between the pectoralis major muscle (superficial) and the external intercostal (deep) muscles and ribs will be identified and the path of the block needle will be determined. After local anesthetic infiltration of the skin with 1% lidocaine, a 80 mm 22G block needle will be inserted at the caudal aspect of the ultrasound probe and advanced in-plane to target the fascial plane directly below the pectoralis major muscle. Once the tip is verified in the correct position, 20 mls of 0.2% ropivacaine will be injected into the plane slowly in 5 ml aliquots under frequent aspiration and correct spread in the interfascial plane will be observed. After injection, patients will be closely monitored until they will be brought to the OR. 4.4. Control Group ((Serratus Block and Parasternal Infrapectoral with 0.9% saline) Before general anesthesia, patients will receive a preoperative 20 mls 0.9% saline injections (total 4 injections) for ultrasound guided bilateral serratus plane and parasternal infrapectoral block with full asepsis and in exact similar fashion as mentioned above. 4.5. Intraoperative Management All subjects will receive a standardized general anesthesia with a laryngeal mask airway or endotracheal intubation depending on the anesthesiologist looking after the patient for their surgery. They will receive intravenous induction using standard doses of fentanyl 1-2 mcg/kg, propofol 2-4 mg/kg and rocuronium 0.6mg/kg if needed. Anesthesia will be maintained with desflurane/sevoflurane (end-tidal concentration corresponding to 1-1.3 MAC, age-corrected) in a mixture of room air (50%) and oxygen (50%). Positive pressure ventilation will only be initiated when spontaneous ventilation cannot be maintained ( e.g. when muscle relaxant is used). Positive pressure support will be titrated to maintain an end-tidal CO2 value of 30-40 mmHg. As per routine practice, fentanyl 1 mcg/kg, morphine 0.05 - 0.1 mg/kg or hydromorphone 0.0075 - 0.015 mg/kg will be administered to treat hemodynamic increases of more than 25% above pre-induction baseline values. As per routine antiemetic prophylaxis, dexamethasone 0.1mg/kg at the beginning of surgery and ondansetron 4 mg IV will be given 30 min before the anticipated end of surgery and dimenhydrinate (gravol) -0.5 mg/kg will only be reserved as a last-line therapy in PACU for otherwise not controllable PONV. Breast reduction surgery will be carried out by either Dr. Yazdani or Dr. DeLyzer. A standard surgical technique is used by both surgeons. Intraoperative tumescent solution containing saline and epinephrine (500 mls of normal saline and 1 mg epinephrine) will be used for injection at the beginning of the case containing saline and epinephrine and no additional local anesthesia will be used. Operative length is approximately 2 hours. 4.6. Postoperative pain management As per routine practice, morphine 2 mg IV or hydromorphone 0.4 mg IV every 5 min as needed will be administered to all patients with pain on a Numeric Rating Scale (NRS) ≥ 4 or after patient request. As soon as oral intake is started, patients will also have access to oxycodone 5 mg PO when needed. Upon discharge from hospital, patients will receive a prescription for Tylenol #3 (acetaminophen 300 mg/codeine 30 mg per tablet) 1-2 tablets every 4 h as needed or Percocet® (acetaminophen 325 mg/oxycodone HCl 5 mg per tablet) if intolerant to codeine. Patients will be contacted over the phone the following day inquiring about their quality of recovery based on the (QoR-15) questionnaire and will also be asked about their level of pain based on numerical analogue score, total and cumulative oral analgesic consumed since discharge from the hospital, opioid-related side effects (nausea, vomitus, pruritus), block-related side effects (numbness and/or weakness) and satisfaction with postoperative analgesia at postoperative days (POD) one.

Ultrasound guided bilateral serratus plane block and bilateral parasternal infrapectoral block with 0.2% ropivacaine.

Ultrasound guided bilateral serratus plane block and bilateral parasternal infrapectoral block with 0.9% saline.

Ultrasound guided bilateral serratus plane block will be performed at the level of 4th rib in anterior axillary line. After skin infiltration with 1% lidocaine, 80mm 22G block needle will be inserted at the caudal aspect of the ultrasound probe and advanced in-plane to target the fascial plane directly below the serratus muscle. Once the tip is verified in the correct position, 20mls of 0.2% ropivacaine will be injected in the plane in 5 mls aliquot after aspiration on each side. Ultrasound guided bilateral parasternal infrapectoral plane block will be performed at the level of 4th rib, lateral to the sterum. After skin infiltration with 1% lidocaine, 80mm 22G block needle will be inserted at the caudal aspect of the ultrasound probe and advanced in-plane to target the fascial plane directly below the pectoralis major muscle. Once the tip is verified in the correct position, 20mls of 0.2% ropivacaine will be injected in the plane slowly in 5 ml aliquots after aspiration on each side.

Ultrasound guided bilateral serratus plane block will be performed at the level of 4th rib in anterior axillary line. After skin infiltration with 1% lidocaine, 80mm 22G block needle will be inserted at the caudal aspect of the ultrasound probe and advanced in-plane to target the fascial plane directly below the serratus muscle. Once the tip is verified in the correct position, 20 mls of 0.9% saline will be injected in the plane in 5 mls aliquot after aspiration on each side. Ultrasound guided bilateral parasternal infrapectoral plane block will be performed at the level of 4th rib, lateral to the sterum. After skin infiltration with 1% lidocaine, 80mm 22G block needle will be inserted at the caudal aspect of the ultrasound probe and advanced in-plane to target the fascial plane directly below the pectoralis major muscle. Once the tip is verified in the correct position, 20 mls of 0.9% saline will be injected in the plane slowly in 5 ml aliquots after aspiration on each side.

Comparing time to hospital discharge; the total time being 'admission to postoperative Care Unit after surgery till discharge home.' this will be measured in minutes

Pain score in admission to phase I recovery (PACU), admission to phase II recovery (day surgery unit), and discharge from day surgery unit.

nausea, vomitus, pruritus and respiratory depression needing medication for treatment or urgent physician assistance.

Inclusion Criteria: women aged 18-70 years ASA I to III (American Society of Anesthesiologists Physical Status Classification System) undergoing bilateral breast reduction surgery day surgery procedures Exclusion Criteria: inability to understand or to provide consent inability or unwillingness to comply with required follow-up assessments psychiatric disorder affecting patient assessment contraindication to regional anesthesia, e.g. coagulopathy allergy to local anesthetic chronic pain and/or chronic use of opioids with a daily use of over 30 mg oxycodone or equivalent per day contraindication to a component of multimodal analgesia preexisting neuropathy with motor or sensory deficits in the area of the anterolateral chest wall infection near injection site pregnancy BMI>35 complication or adverse events unrelated to the study intervention that precludes evaluation of the primary and secondary outcomes

Plan to publish/ share the aggregate summary of the results instead of individual patient data. Individual patients de - identified results could be shared depending on journal requirement at time of publication.

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