Breast cancer has been ranked number one cancer in Indian females. Surgery being the main stay of treatment, General anaesthesia is conventionally used for most breast surgeries. Opioids and NSAID’S are commonly used for analgesia. In female population undergoing breast cancer surgery it has been estimated that the incidence of chronic postoperative pain ranges from 25% to 50%. Among main factors responsible for it being the higher acute postoperative pain, its intensity and analgesic consumption in the acute postoperative period. One important side effect of opioids usage is PONV. Postoperative nausea and vomiting (PONV) continue to be one of the most common and disturbing complications patients experience after surgery, with an incidence as high as 80%. PONV has significant morbidity (dehydration, wound dehiscence, pain, immobility), delayed discharge, increased hospital costs, and poor patient satisfaction. 

Regional anaesthesia is widely preferred these days as they decrease the opioid requirements, thereby reducing their side effects as well. It also provides a good mode of analgesia. Regional anaesthesia commenced before surgical incision reduces incidence of chronic postsurgical pain and Post Mastectomy Pain Syndrome prevalence.THE ERECTOR SPINAE BLOCK (ESB) is an interfascial plane block. It produces extensive multidermatomal sensory blockade with its likely site of action at the dorsal and ventral rami of the thoracic spinal nerves. Local anesthetic deposited deep to erector spinae muscle which extends along the length of thoracolumbar spine, this plane permits extensive cranio-caudal spread and coverage of multiple dermatomes. It’s a promising technique for thoracic analgesia in chronic neuropathic as well as acute post-surgical and post traumatic pain.  Even though many Regional techniques for breast surgeries has shown many benefits over General anesthesia alone, the significant advantage of the ESP Block being its simplicity and safety, not time consuming and considered a better alternative to other techniques in breast cancer surgeries. The sonoanatomy is easily recognizable, and there are no structures at risk of needle injury in the immediate vicinity. Recently published Case reports of Erector spinae block being used as a regional technique in breast surgeries have shown better post op outcome and analgesia, opioid sparing effect, possible immunomodulatory effect and better patient satisfaction. However, except for these case reports on ESB for Breast surgeries, no RCT has been conducted so far, to prove the efficacy of ESB in breast surgeries over General Anesthesia alone and if it can be routinely preferred as a regional technique in breast surgeries.

AIMS AND OBJECTIVES: 

The OBJECTIVE of the study is to find the efficacy of ESB in controlling pain in Breast surgery patients 

PRIMARY AIM is to compare the following in patients undergoing Modified Radical Mastectomy with Axillary dissection/clearance under General Anaesthesia alone and in patients receiving Erector spinae block along with General Anaesthesia, 

1.Time to first analgesic requirement (Time between admission in PACU to request for first rescue pain medication) 

SECONDARY AIM is to compare the following between two groups: 

1. Total intraoperative opioid consumption 

2. Post-operative pain scores 

3. To assess Incidence of PONV 

4. Patient satisfaction scores at discharge

STUDY DESIGN:

Prospective, interventional, Double blinded, comparative Randomised controlled study 

MATERIALS AND METHODS: 

After approval from Institutional Review Board, Patients belonging to the inclusion criteria will be recruited in the study after obtaining a written consent. Since the study will presented as a thesis for MD (Anaesthesia) in May 2020 and will not be able to recruit all the subjects before December 2019, the data of patients recruited till 30 th November 2019 will be analysed for thesis purpose. It will be carried out at Tata Memorial Centre, Mumbai.

Sample size: 

In a Previous study done by somia et al, on Modified PECS block in breast surgeries,Time to rescue(TTR) analgesic increased by 2.30hrs, we expect that the Erector spinae block would prolong TTR by 4Hrs. In order to achieve this, we have taken SD=2, Significance level (alpha) of 0.05, power 80%, the actual sample size calculated is 25 patients in each arm, but we have taken 35 patients in each control and study arm respectively, to account for errors, protocol violations, etc, a total of 70 patients, 35 in each group will be randomised in the trial 

Randomisation would be by computer generated random numbers, and patients will be divided into two study groups 

Blinding: This is a Double blinded study. The patients are blinded as they are given the block under anaesthesia. The block will be given in induction room where OT anaesthetists will not be present. The Acute Pain service team who evaluates patient in PACU and ward are also blinded and wouldn’t know if the patient has received the block or not.

STUDY PROCEDURE: 

GROUP A: These patients will undergo Breast surgery under General Anaesthesia. In induction room, Under All standard anaesthesia monitoring, Induction of anaesthesia will be done by Propofol 1-2mg/kg, fentanyl 2mcg/kg and Muscle relaxant Atracurium 0.4-0.5mg/kg or Vecuronium 0.1mg/kg. An appropriate size Supraglottic device/ETT will be placed. 

Whereas in GROUP B: Patients will be placed in lateral decubitus position after induction, USG guided, probe in parasagittal plane, up to 3cm lateral to midline of at level of 5th thoracic vertebra, using in-plane technique, Erector spinae muscle is identified, and drug is deposited below the muscle using a 20G,10cm Stimuplex needle and 20ml of 0.25% Bupivacaine will be injected into the plane. The block will be performed by PI, CO PI and CI, under the supervision of PI/CO PI, provided the PI & CI had given at least 10 blocks under guidance of CO PI who has good expertise in giving this block. Patients are shifted to Operation room, and Maintenance will be with O2+Air+Sevoflurane+IPPV. Intra op Fentanyl bolus of 0.5mcg/kg iv will be given with 20% increase in heart rate/Blood pressure from baseline Intra-op Paracetamol 15mg/kg iv, Inj Diclofenac 1mg/kg and Inj Ondansetron 4mg, Dexamethasone 4mg will be given for Pain and PONV prevention respectively. Neuromuscular blockade will be reversed with Neostigmine+ Glycopyrrolate, SLMA/ETT removed and patient will be shifted to PACU

In PACU,

At the time of performance of block, it’s not possible to check the dermatomal spread, as patient is under Anesthesia. But in post op period, in PACU, dermatomal spread can be checked using Ice test once patient is wide awake Time to first rescue analgesic (time point measured from end of surgery to request of analgesic OR pain score >/= 4) will be noted in both group of patients. All the patients will be followed up in ward after discharge from PACU, we will monitor all the patients in PACU or ward till they receive the first rescue. Inj Fentanyl bolus iv will be given as first rescue analgesic if Pain score >/= 4 or patient requests for pain medication. (If Within 8hrs of intra-op paracetamol) Inj Paracetamol 15mg/kg will be given (If more than 8hrs from intraop paracetamol) Also, Total opioid and analgesic consumption, pain scores, and Incidence of PONV in first 24 hours/until discharge will be recorded in both group of patients Pain scores will be assessed by the Acute Pain Services, who are blinded to the study, using a Numerical rating scale(NRS) on a scale of 0-10, (0 being no pain and 10 being worst pain) and recorded on arrival to PACU, at 1 hr, 2hrs, 6hrs, 12hrs and by the end of 24hrs/ Or until discharge To assess Incidence of PONV – Nausea as yes/no and Vomiting, assessed both by binary variable(yes/no) and as continuous variable to measure the number of separate emetic events. Patient satisfaction score will be assessed in PACU by a scoring system of 1-4. 1- Not satisfied, 2- Fairly satisfied, 3- Satisfied, 4- Extremely satisfied.