Adding Magnesium Sulfate to Bupivacaine in Ultrasound Guided Paravertebral Block for Laparoscopic Cholecystectomy
Condition: Laparoscopic Cholecystectomy
Study type: Interventional

Summary: 
      Laparoscopic cholecystectomy is one of the most commonly performed minimally invasive
      surgical procedures for the treatment of symptomatic cholelithiasis Laparoscopic
      cholecystectomy has clear benefits when compared with open surgery, but post-operative pain
      is still a common complaint after it The patient undergoing laparoscopic cholecystectomy
      suffers from severe post-operative pain, it can prolong hospital stay and lead to increased
      morbidity Post-operative laparoscopic cholecystectomy pain can be relieved by some methods
      pre-emptive analgesic regimens containing ketamine, regional anesthesia techniques including
      paravertebral block Paravertebral Block is a regional anesthetic and analgesic technique
      which may offer comparable analgesic effectiveness with minimal side effects Paravertebral
      Block has been used a lot in the last two decades, several studies show its efficacy in,
      thoracoscopic surgery and laparoscopic cholecystectomy .Paravertebral block is the technique
      of injecting local anesthetic adjacent to the thoracic vertebra close to where the spinal
      nerves emerge from the intervertebral foramina, resulting in ipsilateral somatic and
      sympathetic nerve blockade in multiple dermatomes above and below the site of injection .

      Bupivacaine is a local anesthetic that is capable of producing prolonged high quality
      analgesia in the postoperative period It is shown that paravertebral block using bupivacaine
      significantly reduces pain score Many drugs have been used as adjuvants to local anesthetic
      in peripheral nerve block in order to augment its analgesic effect and prolong the duration
      of the block such as opioids and magnesium sulfate Many studies have reported safety and
      efficacy of adding magnesium to local anesthetics in various regional anesthetic procedures,
      such as intrathecal, epidural, caudal, brachial plexus blocks and intravenous regional
      anesthesia. Magnesium play a major role in central nociceptive transmission, modulation and
      sensitization of acute and chronic pain states due to its antagonistic effect on N-methyl
      D-aspartate (NMDA) receptors .
    

Detailed description: 
      Patients and Methods

      Patients:

      This is a blind prospective randomized controlled study that will be conducted for one year
      in Mansoura university hospitals after approval from the Institutional Research Board (IRB),
      Faculty of Medicine, Mansoura University, patients will be interviewed and written informed
      consents will be obtained. This study will include 26 patients of American Society of
      Anesthesiologists physical status grade I and grade II, of both sexes, aged between 20-60
      years who will be scheduled for laparoscopic cholecystectomy.

      Sample size calculation A Priori G-power analysis was done to estimate study sample size. A
      power of 90% was estimated with type I error of 0.05 to get an analgesic duration difference
      between groups of approximately 30% to yield of total sample size of 50 cases (25cases per
      group).

      Randomization:

      Fifty patients (number = 50) had laparoscopic cholecystectomy and bilateral paravertebral
      block during the study period. These patients were randomly allocated to undergo bilateral
      ultrasound guided paravertebral block. The groups allocated are concealed in sealed opaque
      envelopes which were not opened until patient consent was obtained.

      The two groups were:

        1. Control group: Bupivacaine Group (B group) Number=25 :

           Included patients who received 17 mL of 0.25% bupivacaine + 3 mL mili saline 0.9% in a
           total volume of 20 ml on each side.

        2. Magnesium Group (M group) N=25 :

      Included patients who received 17 mL of 0.25% bupivacaine + 3 mL of 75 mg milgram magnesium
      sulfate diluted in 0.9% saline in a total volume of 20 ml on each side.

      All patients were performed by the same anesthetic team with standard procedure.

      Methodology:

      Anesthetic Management:

      Preoperative Management:

      All patients will be visited a day prior to surgery and will be assessed preoperatively by
      History, physical examination and laboratory evaluation (complete blood picture, coagulation
      profile, liver function and renal function tests). The study protocol and paravertebral block
      procedure will be explained to all patients. All patients will be familiar with the use of
      0-10 visual analogue scale score identifying 0 as no pain and 10 as worst imaginable pain.
      Patient fast 6-8 hour before the time of surgery.

      On arrival of the patient to the operating room routine monitoring will be applied,
      peripheral intravenous cannula 20 gauge will be inserted and 0.9% saline will be started to
      be infused. All patients will be premedicated using midazolam 0.03 mg/kg kilo intravenous.

      Paravertebral block will be performed before induction of general anesthesia.

      Technique of ultrasound guided paravertebral nerve block:

        -  Standard precautions for the performance of ultrasound-guided nerve blocks will be
           followed which include continuous routine monitoring, the skin overlying the injection
           site should be free of signs of infection and prepped with an antiseptic solution.

        -  Patient will lay in the lateral position, paravertebral block will be done using a 38 mm
           mile meter broadband linear array ultrasound probe.The probe surface in contact with the
           skin should be covered with a sterile adhesive dressing.

        -  A sagittal paramedian view of the paravertebral space will be obtained by applying the
           probe at a point 2.5 cm centimeter lateral to the tip of the spinous process in a
           vertical orientation, The fifth thoracic vertebral level will be identified by palpating
           and counting down from the seventh cervical body.

        -  The midpoint of the transducer will be aligned midway between the transverse processes
           of thoracic vertebra T5 and T6, 4 ml of 1 % lidocaine was injected subcutaneously at the
           puncture site,and 22 gauge spinal needle will be inserted in an in plane approach in a
           cephalad orientation and will be advanced perpendicularly to all skin planes under
           direct vision to puncture the superior costotransverse ligament where a click may be
           appreciated.

        -  Following negative aspiration, 1-2 ml of study solution will be injected to verify
           correct position of the needle tip and the rest of study solution will be injected in
           fractioned doses following intermittent aspiration between the superior costotransverse
           ligament and the parietal pleura which will be displaced anteriorly by the injectate.

        -  Similar approach will be used for the paravertebral block on the other side.

        -  Sensory block over the area of surgical incision will be confirmed by loss of cold
           sensation using an alcohol swab and pinprick sensation using a 23 G gauge needle every 3
           mint until 15 min after injection of the study solutions and before starting general
           anesthesia.

      General Anesthesia:

      General Anesthesia will be induced using intravenous propofol (2-3 mg/kg), fentanyl IV
      (1µ/kg) microgram/kilo and atracurium besylate (0.6 mg/kg) to facilitate intubation. Then
      patient will be mechanically ventilated using a volume control mode with Tv 6-8ml/kg,
      respiratory rate 10-14 breath/min and I.E. ratio 1:2 to maintain Etco2 35-40 mmHg mli
      mercury. Anesthesia will be maintained using minimum alveolar concentration of isoflurane
      1.2% and 60% air in O2 mixture with top up dose of atracurium. Intraoperative IV fluids will
      be given per body weight and according to intraoperative loss.

      All patients will be extubated at the end of surgery after neuromuscular reversal with
      administration of neostigmine (0.05 mg/kg) and IV atropine (0.02 mg/kg) and fulfilling the
      criteria of extubation. The duration of the surgery will be recorded.

      Monitoring:

      Intra-operative assessment

        -  In operating room, monitoring will be achieved by five lead electro cardi gram, oxygen
           saturation and non-invasive mean arterial blood pressure.

        -  Base line values of heart rate, oxygen saturation and non-invasive mean arterial blood
           pressure will be collected before and after paravertebral block, just after induction of
           anesthesia, at skin incision, then recording will be done every 15 mint till the end of
           the first hour and then every 30min interval till the end of surgery.

        -  Sensory block onset will be defined when the patient subjectively evaluate the
           intensities of both cold and pinprick sensations in the blocked side decrease 75 % or
           more.

        -  Duration of surgery will be defined as the time from induction to discharge from the
           operating room will be recorded.

        -  In case of increased in intra-operative systolic blood pressure and heart rate of more
           than 20% of baseline for longer than 5min, incremental doses of fentanyl IV 0.5µ/kg will
           be given and the case will be excluded.

      Postoperative Assessment:

        -  On admission into the post operative care unit, all vital data & hemodynamics
           (non-invasive mean arterial blood pressure, heart rate, and oxygen saturation) will be
           recorded at 1, 2, 6, 12 and 24 hrs. postoperative

        -  Post-operative complications will be recorded including post-operative nausea and
           vomiting treated by metoclopramide, hypotension treated by phenylephrine drops,
           bradycardia treated by atropine or pneumothorax, respiratory depression and chest pain,
           respiratory depression is defined as respiratory rate less than 8 per minute or oxygen
           saturation below 90%.

      Statistical analysis The statistical analysis of data will be done by using excel program for
      figures and Statistical Package for Social Science program version 22. To test the normality
      of data distribution Kolmogorov- Smirnov test will be done only significant data revealed to
      be nonparametric. Unpaired student-t test will be used for comparisons of numerical variables
      between-group, if its assumptions were fulfilled, otherwise for non-parametric; the
      Mann-Whitney test will be used. The description of data done in the form of mean (±SD)
      stander division for quantitative data and frequency and proportion for qualitative data. Any
      difference or change showing probability (P) less than 0.05 will be considered statistically
      significant at confidence interval 95%.
    

Intervention name(s): Bupivacain; magnesium sulfate; saline
Intervention type(s): Drug; Drug; Other
Intervention description(s): local anesthetic agent; In the central nervous system , it has depressant effects, by antagonism at NMDA receptors and through inhibition of release of catecholamines; medical solution
Other intervention name(s): Control group: Bupivacaine Group (B group; Saline; Magnesium Group (M group); saline
Intervention MeSH terms: Magnesium Sulfate; Bupivacaine
Allocation: Randomized
Intervention model: Sequential Assignment
Intervention model description: The groups allocated are concealed in sealed opaque envelopes which were not opened until patient consent was obtained.
The two groups were:
Control group: Bupivacaine Group (B group) N=25 :
Included patients who received 17 mL of 0.25% bupivacaine + 3 mL saline 0.9% in a total volume of 20 ml on each side.
Magnesium Group (M group) N=25 :
Included patients who received 17 mL of 0.25% bupivacaine + 3 mL of 75 mg magnesium sulfate diluted in 0.9% saline in a total volume of 20 ml on each side.
All patients were performed by the same anesthetic team with standard procedure.
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: paravertebral block laparoscopic cholecystectomy