Efficacy of ultrasound Guided Erector Spinae Plane Block in Percutaneous Nephrolithotomy (PCNL)Surgery.

A sealed envelope randomization willbe employed to allocate patients  intotwo groups  either  to  receive ESP  block with local anaesthetic drug  bupivacaine and patient receiving ESP blockwith normal saline.

Patient will be premedicated withintravenous inj. glycopyrrolate (5mcg/kg), inj. Midazolam (0.05mg/kg), inj.Fentanyl (2mcg/kg). Induction will be achieved by inj.  Propofol (2mg/kg) and intubation will befacilitated with inj. vecuronium (0.08mg/kg). Anaesthesia will be maintainedwith 50% of nitrous oxide in oxygen and isoflurane along with inj.vecuronium(0.02mg/kg) maintenance dose as required.  All hemodynamics parameter will be recordedat every 15 min interval until patient will be shifted from the operating room.

Erectorspinae plane  block  will be performed  after completion ofpcnl surgery  under  ultrasound guidance  using  a linear  transducer.

Group E (n=30):  group E will receive  Erector Spinae  Plane Block with  Local Anaesthetic (LA) mixture  10 ml of 0.5% Bupivacaine, 5 ml of  Lignocaine2%, 1 ml (50mcg) of fentanyl, 4 ml of  NS  to make  a  mixture of  20 ml,  which  will be  injected on the side of surgery.

Group C (n=30):  group C willreceive Erector  Spinae  Plane Block with 20 ml of   normal saline   injected on the side of surgery.

InGroup E patients, Erector  Spinae Plane (ESP) block  will be  performed  in prone position  after  ensuring skin  asepsis, we  place high  frequency [5-13 MHz]  linear ultrasound  transducer  in sterile  sheath  3 cm lateral  to  the  T9  spinous  processto visualize  the  back  muscles:trapezius  above, rhomboid  major  in the  middle, and erector spinae  muscle  on the  bottom. A 23G 10-cm  Touhy  needle  will be  inserted  using  an in plane  superior to inferior approach  until the needle touched the TransverseProcess  crossing all three muscles. Avolume  of  20 ml  of LA  mixture  will  be injected.

In GroupC  patients, same procedure as above will beperformed, but in place of drug we will inject a volume of 20 ml of  normal saline on the surgery side.

After completion of ESP blockprocedure, all  the anaesthetic agentwill be stopped and after the onset of spontaneous respiration, residualneuromuscular blockade will be reversed with Inj. Neostigmine (5mcg/kg) andInj. Glycopyrrolate (10 mcg/kg)  and  extubation will  be  done. before shifting the pts to postoperative ward we will give injectionparacetamol 15mg/kg body wt as analgesic to all pts.

PTs will be assessed for pain by VASscores (ranging from 0 indicating no pain to 10 indicate extreme pain) will berecorded 30 min and 2,4,6,12,and 24 hr. postoperatively.

When VASScore is more then 4 we will give intravenous tramadol 100 mg (maximum up to400 mg) as postoperative rescue analgesic. . The  amount of  rescue  analgesia  require in  both  groups during  first  24h  after operation , pts satisfactionscore using Likert Verbal Rating  Scaleand complications if any occur  will  be  recorded.

The  hemodynamic parameters  like  Heart rate, Systolic Blood pressure,Diastolic blood pressure , Mean arterial pressure, Saturation(spo2), Etco2will  be taken  after  the block and  patients  will be  monitered  upto 24  hrs  after the  block.  Adverse events  such  as Bradycardia (HR <50 bpm  or  20% decrease  from  the baseline value), Hypotension (fall  in  blood pressure  by  20% from  the  baseline or an  absolute MAP <60 mmHg) , Nausea, Vomiting,  Dryness  of mouth  or  any other  events  during or  within   the procedure  will  be noted. Bradycardia  will  be treated with  increment  doses of  injection  Atropine 0.3mg  and Hypotension  will be  managed with  a  bolus of  IV  crystalloids or  with  increments of  injection Mephentermine  6 mg.