INTRODUCTION

 

Thoracic surgery, particularly Decortication procedures, is associated with considerable postoperative pain [1]. Pain associated with decortication can be attributed to the significant trauma caused by the incision, including dislocation of costo vertebral joints, retraction of tissue bordering the surgical field, fracture of ribs, injury to inter costal nerves, pleural irritation, and resection of multiple layers of muscle

Since uncontrolled pain can result in respiratory problems such as a telectasis, diaphragmatic dysfunction, respiratory failure, splinting, and inefficient coughing, which can progress to pneumonia and postoperative mechanical ventilation support.

There are multimodal analgesia approach in post thoracotomy patients like central neuraxial block, peripheral nerve block, intravenous, transdermal and oral medication as well (2,3)

Erector spinae plane (ESB) block is new evolving technique in which ultrasound guided local anesthetic is injected between transverse process and erector spinae muscle. ESP block was first described by for ero et al in 2016 (4) for effective pain management of thoracic surgery. Several studies have shown that giving local anesthetic in this plane spread to paravertebral space and spread caudally and cranially and cover multi-dermal level. (5, 6) and block ventral as well as dorsal rami. It has similar efficacy to thoracic epidural and para vertebral block in pain control and lesser chances of hypotension and brady cardia but have high failure rate (7,8)

The Midpoint transverse process to pleura (MTP) block was first described as a modified paravertebral block in 2017 is relatively new technique and end point of paravertebral block in which drugs is administered in between transverse process to pleura. (9)This results in a LA spread to the dorsal and ventral rami in the paravertebral space through the fenestrations in the superior costo transverse ligament at the level of injection, and frequently to adjacent levels.

Both techniques were used for pain relief after mastectomy, thoracic, abdominal, and spinal surgery and were found effective due to their simplicity and lower risks compared to epidural analgesia [10];

Since above technique has been used for post-operative analgesia purpose in many surgery, We have aimed our study to compare ESP block with MTP block for postoperative analgesia in patients undergoing thoracotomy for decortication surgery.

AIM AND OBJECTIVE

 

The aim of the study is to compare post operative analgesic effect between erector spinae plane (ESP) block and mid transverse to pleura (MTP) block in decortication surgery.

 

Primary Objective

 

·        To compare visual analogue scale (VAS) score between ESP block and MTP block in first 24 hours post-operatively of decortication surgery.

 

Secondary Objective To compare following parameter between ESP block (Group A) and MTP block (Group B)

·        Time of first need of rescue analgesia

·        Total dosage of rescue analgesia used in 24 hrs

·        Patient satisfaction score by 5-point Likert scale 24 hrs after surgery

·        Any inadvertent complications like bleeding, /pneumothorax/swelling during 24 hrs after procedure

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MATERIALS & METHODS

 

Study Settings

 

The study will be conducted   in   Department   of   Anaesthesiology in collaboration with General surgery department of King George’s Medical University Lucknow after taking written and informed consent from the patient.

 

Study duration

One year 

Study design

Prospective, Randomized comparative, single blinded study

 

Sample size calculation: Sample Size at 90% Power:

 

Sample size is calculated on the basis of maximum variation in VAS score (Ref. Eskin MB et al (10).  during observation time in two groups using the formula.

 

 

 

 

 

Where (1 = 0.9, The maximum SD of VAS score during observation time in erector spinae block group

(2 = 1.1, The final SD of Lycopene concentration during the follow up period in Mid transverse to pleura block group

D = min (1, (2), the difference considered to be clinically significant

K = 1.0 the effect size

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 = 32 each group

Considering loss to followup of some patients due to some reason like need of post operative ventilatory support and some other exclusions we will enroll 35 patients in each group with total 70 patients.

 

Inclusion Criteria:

 

1.    Patients of either sex aged18-65years of ASA physical II or III 

2.      Patients planned for decortication surgery under general anesthesia

Exclusion Criteria:

 

1.      Patient refusal

2         Allergy to local anaesthetics.

3         Localized infection,

4         Bleeding diathesis,

5         Patients on anticoagulants,

6         Pre-existing neurological deficit, Liver failure, Cardiac failure

7         Spinal deformities,

8        Cognitive impairment, an active psychiatric condition

 The study will be conducted after getting approval   from   ethics committee of King George’ s Medical University Lucknow and CTRI registration. All enrolled patients will be randomized by computer generated system and allocated to one of the two groups.

Group A: Patients who will be given ultrasound guided erector spinae plane (ESP) block.

Group B:   Patients   who will be given ultrasound guided midpoint transverse process to pleura (MTP) block

A routine thorough pre-anesthetic checkup will be conducted and it included taking a detailed history, looking for comorbidities, and allergy to any drug being used and doing a general physical and systemic examination. Patients   will   be   explained   about the study and written informed consent will be taken. The patients will be also be educated about the use of visual analogue scale (VAS).

On arrival in the operating room, patients will be subjected to the standard multichannel monitoring with ECG, non invasive arterial blood pressure, heart rate, temperature and oxygen saturation and all base line vitals parameter will be recorded. Large bore cannula was placed and drip was connected with isotonic fluid.

General anesthesia was induced using IV propofol (2mgkg–1), vecuronium (0.08 mg/kg), and fentanyl (1 μg/kg). A cuffed and armored endotracheal Tube (no. 7–8.5) was placed to secure the airway. The patients were positioned in lateral position for surgical procedure. The fluid was administered as per standard protocol and vitals were recorded at regular interval. The anaesthesia was maintained with oxygen, sevoflurane and fentanyl.

 

 

 

Both blocks will be done in same Lateral Decubitus position at T5-T6 level just after surgery. An ultrasound with high frequency (8-12MHz) linear transducer probe will be used probe will be placed paramedian sagittal plane. Needle inserted in plane from caudal to cranial direction InESPB- plane local anaesthetics were given in plane between erector spinae and transverse process just above the incision site for thoracotomy. In MTP local anaesthetics were given in a space midway between midpoint of two adjacent transverse process and pleura in same incision site of thoracotomy procedure. (figure 1 and 2)

 

    Figure 1

Figure2

 

 

 

 

 

The correct needle position was confirmed after a hydro dissection with 3ml of isotonic saline then 20ml of 0.25% Levo-bupivacaine and 2ml of dexamethasone (8 mg, total volume 22 ml) is injected into corresponding area.

In the post operative period, VAS score will be taken at- just after surgery,          1 hour, 2hours, 4 hours, 6hours, 12 hours, 18hours and 24 hours after surgery. All patients will be given1gm Paracetamol infusion, 1^st dose just after completion of surgery and then 8 hourly till 24 hours in both group.

Intravenous tramadol will be used as rescue analgesic in post-operative period when VAS score >4 at any point of assessment or when patients himself demanded for analgesia (time of first dose of rescue analgesia) will be noted.

 In each dose we will give 100mg tramadol and second dose will not be repeated in<8hours period with maximum 300mg in 24hours period. If patient needed analgesia requirement before 8 hours of first rescue analgesic, second rescue will be given in the form of intravenous diclofenac 75 mg.

Primary outcome is the average no VAS score initial 24 hours post operatively at 1 hour, 2 hours, 4hours, 6hours, 12 hours, 18hours, 24hours. Secondary outcomes are time for first need of rescue analgesic dose and total rescue analgesic dose were calculated Patients at is faction score, measured by asking the patient to rate their      satisfaction on a 5-point Likert scale (1-very dissatisfied, 2- dissatisfied, 3- neither dissatisfied or satisfied, 4- satisfied, 5-    Very satisfied) 24 h after surgery in the post anaesthesia care unit (PACU).

                  Any inadvertent complications like bleeding, / pneumothorax / swelling during 24 hrs after procedure were noted. All data will be collected and summarized in excel chart and subjected to statistical analysis.

 

 

 

 

 

 

 

 

 

 

STATISTIC ALANALYSIS

The data will be expressed as mean and standard deviation (SD) or median, range and percentage as appropriate. All the categorical data will be compared by using chi square test. Continuous variables in two groups will be compared byt-test. The p-value <0.05 will be considered as significant. The statistical analysis will be done using SPSS21.0 version (Chicago, Inc., USA) Windows   software.

REVIEW OF LITERATURE

 

Fang B,[8]Ninety-four patients scheduled for thoracotomy lung surgeries were randomly allocated to an ESPB or TPVB group.  Visual analogue scale (VAS) pain scores under the status of rest and cough were recorded at 1, 6, 12, and 24 h postoperatively. here were no significant differences in pain scores at rest and cough between the ESPB and TPVB groups in each of the first two days after surgery, and no difference between the two groups was identified regarding postoperative sufentanil usage (P>0.05). . There was no statistical difference in post-operative nausea and vomiting. There was significantly less hypotension (6.7% vs. 21.7%, P=0.04), bradycardia (0 vs. 8.7%, P=0.04), hematoma (0 vs. 10.9%, P=0.02) and a higher success rate of one puncture (82.2% vs. 54.3%, P<0.001) in the ESPB group.

.Eskin,[10] A total of 120 adult patients were included in the study and randomized into 3 groups: group ESP (n = 40), group MTP (n = 40) and group Control (n = 40).  Mean VAS scores were significantly higher in the group Control than in the group MTP and group ESP at all-time points during 48 h (Control > MTP > ESP; p < 0.001). Mean VAS scores were lower in group ESP than group MTP in postoperative 12 h (p < 0.001). Rescue analgesic consumption, number of bolus demand on PCA, PCA bolus demand dose, total PCA dose, and complications related to opioid consumption were highest in control group and lowest in ESP group (Control > MTP > ESP; p < 0.001).  Both ESP and MTP blocks provided effective pain relief after lumbar spinal surgery but the ESP block was superior to MTP block regarding postoperative analgesia in the first 24 hr.