European Journal of Cardiovascular Medicine

Breast cancer account for one-third of cancer burden in the world. Among the Indian women, it has increased as that of cervical cancer and has become the most common cancer with 26 per one million population and mortality of 13 per million population. General Anesthesia (GA) is the most common technique used for surgery of breast cancer. GA alone cannot achieve adequate postoperative pain control ^[2] Some additional approach like regional blocks are must to undertake post operative analgesia, the benefits include a prolonged postoperative pain relief, decrease in postoperative nausea and vomiting (PONV) and potential for early discharge ^[3].

Bupivacaine binds to the sodium channels and blocks influx of sodium to nerve cells and prevents depolarization. Amide group of local anaesthetics like bupivacaine are primarily metabolized in the liver by conjugation with glucuronic acid. However it was noted that by the use of racemic mixture of bupivacaine resulted in cardiovascular and central nervous system toxicity among some patients ^[4-5].

Ropivacaine is a long-acting amide group of local anaesthetic which has improved safety profile in comparison to bupivacaine ^[6-7]. Ropivacaine is less lipophilic compared to bupivacaine, it is less likely to penetrate large myelinated motor fibres, hence resulting in reduced motor blockade. Ropivacaine has a higher degree of motor sensory differentiation. Ropivacaine has selective action on the pain-transmitting A β and C nerves rather than Aβ fibres, which are responsible for motor function. Many comparative studies between bupivacaine and ropivacaine suggests that ropivacaine produces less cardiovascular as well as less central nervous system toxic effects, less motor block and a equal duration of sensory analgesia as bupivacaine ^[8,9].

Blanco R in two thousand and eleven, illustrated the procedure of Pectoral Nerve (PECS) block and its effectiveness in reducing pain over the pectoral area during breast surgeries. ^[10].This study was an initiative to provide further development for the efficacy and safety of this procedure towards pain management in mastectomy surgeries. Our aim of the study is to prove potential advantages of Ropivacaine and Bupivacaine in TTM and PECS block for providing analgesia in postoperative period of mastectomy surgery by assessing VAS score and other parameters.

After obtaining institutional ethical committee approval 60 patients of ASA 1 , 2 &3 patients undergoing mastectomy surgery with axillary clearance admitted under the Department of Surgery at SIMSRC Mangalore. During the period of NOV 2021 to OCT 2023.

Study Design: Randomized Double blinded Prospective study.

Sample Size: 60 females undergoing unilateral mastectomy were randomly allocated into two groups.

R Group : 30 patients receive USG guided PECS Block and TTP Block. 0.2 % Ropivacaine 10 ml was injected in PECS 1 Block and 20ml was injected in PECS 2 Block and 15 ml was injected in TTP Block.

B Group: 30 patients receive USG guided PECS Block and TTP Block.0.25 % Bupivacaine 10 ml was injected in PECS 1 Block & 20 ml was injected in PECS 2 Block and 15 ml was injected in TTP block.

1. Inclusion Criteria:

1) All ASA 1, 2 and 3 patients

2) Breast cancer surgery with axillary clearance.

1. Exclusion Criteria
2. ASA 4 patients.
3. Allergy to local and general anaesthetic drugs.
4. Presence of infection.
5. Patients on anti-coagulants or anti-platelet drugs.

All Patients underwent routine pre-anaesthetic evaluation and all patients recruited were either ASA 1, 2 and 3. Fasting protocols were followed. Patients were kept NPO for up to six hours for solids and milk; two hours for clear fluids like water. On the morning of surgery the patients were reassessed and taken in to the OT .The anaesthesia machine, emergency oxygen source, pipeline oxygen supply, working laryngoscope were checked as routine manner. Working suction apparatus with catheter should kept ready, airway equipment, intravenous fluids and all emergency drugs were kept ready for emergency resuscitation.

Intervention

Group-B: Received general anaesthesia followed by ultrasound-guided PECS-I and II block and TTP block using 0.25% Bupivacaine.

Group-R : Received general anaesthesia followed by ultrasound-guided PECS-I and II block and TTP block using 0.2% Ropivacaine.

General anaesthesia induced with Inj. fentanyl 2mcg/kg and Inj. propofol 2 mg/kg ,Neuromuscular block achieved with Inj. Atracurium 0.5mg/kg and the trachea intubated and connected to closed circuit. Anaesthesia maintained with Sevoflurane 1MAC in oxygen and nitrous oxide 1:2 with Atracurium in titrated doses. After induction of anaesthesia for B group USG guided PECS 1 Block with Inj. Bupivacaine 0.25% 10 ml to be injected between pectoralis major and pectoralis minor muscle at the 3rd rib. PECS 2 block with Inj. Bupivacaine 0.25%, 20ml was injected above the serratus anterior muscle. For Transversus thoracic muscle plane block with Bupivacaine 0.25%,15 ml to be injected between the transversus thoracic muscle and internal inter costal muscle between the fourth and fifth ribs connecting at the sternum. After induction of anaesthesia for R group USG guided PECS 1 Block with Inj. Ropivacaine 0.2% ,10 ml to be injected between pectoralis major and pectoralis minor muscle at the 3rd rib. PECS 2 block with Inj. Ropivacaine 0.2%,20 ml to be injected above the serratus anterior muscle. For transversus thoracic plane block with Ropivacaine 0.2%,15 ml to be injected between the transversus thoracic muscle and internal inter costal muscle between the fourth and fifth ribs connecting at the sternum. In the post operative ward Pulse rate, Blood pressure will be monitored. Post operative pain score to be assessed using visual analog score(VAS score,0-10,0=no pain,10=worst pain.) VAS score to be obtained at 1,6,12 and 24 hrs after surgery.

Intra-operative Period

Any increases in heart rate and blood pressure to more than 15% of the baseline was treated as a pain response and noted after the patient was under adequate plane of anaesthesia. All the patients remained hemodynamically stable throughout the procedure.

Intraoperative vitals were monitored routinely. Systolic and Diastolic BP along with HR and ET Co2 and saturation was recorded. After completion of the procedure, patient was reversed with neostigmine 0.05mg/kg and glycopyrrolate 0.01mg/kg and patients were extubated after the criteria for extubation were met.

Post-operative Period

After the procedure patients were transferred to PACU, Pain score was documented against Visual Analog Scale scale on 1 st hour ,6^th hr,12^th hour and 24^th hour.

Pain Assessment Tool: Visual Analog

The Numerical Rating Scale has shown a high correlations as compared to other pain-assessment tools. The patients were instructed to circle the number between 0 and 10, zero representing “no pain at all” whereas the upper limit represents “the worst pain possible”.

Table 1: Age distribution

Figure

Table 2: VAS Score

Figure

Table 3: Pulse rate

Table 4: Blood Pressure (MAP)

Modified Radical Mastectomy produce severe pain and discomfort ,an adequate analgesia can decrease this pain-related morbidity. when compared to bupivacaine, ropivacaine produces a higher sensorimotor differential block which has the benefit of a shorter elimination half-life ,it also has lower potential for accumulation. Compared to bupivacaine , ropivacaine has lower risk of toxicity.

The onset of sensory block in Ropivacaine group (5 mins) is lower as compared to bupivacaine group(10mins) , Compared to bupivacaine group the quality of block was higher in ropivacaine group as at 10minute interval (p<0.001). The results are comparable to those obtained by Bertini et al., ^[11] who observed rate of complete sensory and motor block with ropivacaine group to be higher at 10, 15 and 20 min postinjection (p<0.001)1. In present study, patients in both the groups achieved peak block level by 25 min. However, mean onset time of block was found to be significantly lower in ropivacaine group (8.88±1.74 min) as compared to bupivacaine group (12.04±2.57 min).

In another study, a paravertebral analgesia-based anaesthetic reduced pain scores and opioid requirements and also reduced the doses of volatile anaesthetics. Meta-analysis concluded that reduction of pain by about 2 points (on a 0–10 visual analog scale [VAS] score) and the use of opioid is reduced by about 70% in the immediate postoperative period of 2 h.^[12]

Kanai et al. also reported significantly less VAS scores in 0.2% ropivacaine compared to 0.125% bupivacaine ^[13]The findings of this study is that 0.2% ropivacaine produces better first stage analgesia than 0.1% bupivacaine with fentanyl 2 μg ml−1 and requires less routine top-ups. This may be due to the longer duration of action of ropivacaine^.[14]

Bashandy et al. ^[15], who studied the beneficial effects of PECS block versus general anaesthesia, reported that VAS scores in the PECS group stayed significantly lower than the general anaesthetic group, at 3 hours and 24 hours post operatively. They also reported total amount of postoperative morphine needed to keep VAS pain scores less than 3 in the PECS was lower than control group (P < 0.001). In addition to the total amount of opioids like morphine and fentanyl consumption was less in the test as compared to control group.

Sun et al. ^[16] in their meta analysis Adding Pecs block to GA procedure results in lower pain scores, less opioid consumption and longer time to first analgesic request in patients undergoing breast cancer surgery compared to GA procedure alone.

In the post operative period the present study showed no statically significant difference in heart rate and blood pressure change in two groups.

Manzoor et al. ^[17] in their RCT study of PECS with bupivacaine versus dexmedetomidine, though noted significant difference in the blood pressure both in systolic and diastolic BP in both the groups in the first postoperative hour. However, there was no significant difference after the 1st hour.

PECS I and PECS II blocks were initially introduced and done by Blanco et al. in 2011, claiming its advantages in pain management during perioperative of reconstructive breast surgery. Their study was performed in 50 patients undergoing mastectomy surgery and reported good analgesia for 8 hours in post op period. Since then there have been multiple studies showing mixed results of this block. Our study was undertaken to see if the PECS I and II block and TTP block could offer quality analgesia for mastectomy surgery and effectiveness and duration of Ropivacaine compared with Bupivacaine.

In our study we compared the efficacy of Bupivacaine and Ropivacaine for post operative analgesia. Ropivacaine group is a newer drug which is wide spread use in regional anaesthesia(R group) nowadays, another drug Bupivacaine routinely used and proven efficacy in regional anaesthesia(B group). There is statistically significant difference in the VAS score between the Bupivacaine and Ropivacaine group at 1st, 6th, 12th and 24th hour with p value of < 0.001, <0.001, <0.001 and <0.001 respectively. No statistically significant difference in age distribution among the two study groups, with a p value of 0.6697. There is statistically significant difference in in pulse rate among the two study groups at 1st, 6th, 12th and 24th hour, with a p value of <0.001, 0.0004, 0.0118, 0.0075 respectively. There is a no statistically significant difference in the mean arterial pressure among the two study groups at 1st, 6th, 12th and 24th hour, with a p value of 0.040, 0.788, 0.099, 0.066 respectively.

The results of our study is supportive, in proving, that 0.2% Ropivacaine is superior to 0.25% Bupivacaine for post-operative analgesia using PECS block and TTP block for breast cancer surgery. It should be considered as an adjuvant therapy multimodal analgesic technique to general anaesthesia.

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