Preoperative Gabapentin Versus Bisoprolol for Hemodynamic Optimization During Sinus Surgery
Condition: Blood Pressure
Study type: Interventional
Phase: Phase 4

Summary: 
      the current study hypothesized that Gabapentin can be effective as Bisoprolol in reduction of
      intraoperative bleeding, improving the operative's field visibility and increase the surgeon
      satisfaction via optimization of blood pressure and heart rate .

      A prospective randomized double blinded controlled study. Eligible patients were randomized
      according to random list generated software and allocated into 3 equal and matched groups (15
      patients in each group):-

        -  Group G: gabapentin group in which Patients were premedicated with oral gabapentin 1200
           mg (Conventin 400mg; Evapharm) with sips of water, 2 hours before induction of
           anesthesia.

        -  Group B: bisoprolol group in which Patients were premedicated with oral bisoprolol 2.5
           mg ( Concor 2.5mg ; Merck/Amoun ) with sips of water, 2 hours before induction of
           anesthesia.

        -  Group C: control group in which Patients were premedicated with oral placebo with sips
           of water, 2 hours before induction of anesthesia.
    

Detailed description: 
      Hypothesis:

      Gabapentin can be effective as Bisoprolol in reduction of intraoperative bleeding, improving
      the operative's field visibility and increase the surgeon satisfaction via optimization of
      blood pressure and heart rate.

      Objectives Compare the effect of preoperative Gabapentin with Bisoprolol on hemodynamics,
      surgical field optimization during endoscopic nasal surgeries.

      Technical design:

      A) Site of study :

      The study was conducted at Anesthesia and Surgical intensive care and Otorhinolaryngology
      departments, faculty of medicine, Zagazig University.

      B) Sample Size :

      According to 80% power of the study, 95% CI and calculated volume of blood loss 200±40 ml and
      150±55ml on Gabapentin (22) and Bisoprolol (15) premedication respectively, the estimated
      Sample size was 54 patients (open EPI) , 63 patients were included in the study to compensate
      for drop out.

      Randomization was carried out on 63 patients to compensate for drop out . All planned ESS
      procedures was managed by the same anesthetist and surgeon who were blinded to the used
      study's premedication. The surgeon was blinded to the monitor recording the hemodynamic
      variables.

      All patients had been preoperatively evaluated according to standard local protocol.
      Preoperative surgical preparation and proper management of infection were confirmed to every
      patient.

      Patient was premedicated by IV ranitidine 50 mg, midazolam 0.05 mg/kg and atropine 20µg/kg
      immediately before admission to the operating room.

      On admission to the operating room, Standard monitoring included 5 leads ECG, non-invasive
      blood pressure, Pulse Oximetry and End-tidal carbon dioxide (ETCO2) trace were applied (B40i
      Monitor - GE Healthcare, Finland).

      Anesthesia was induced with IV propofol 2 mg/kg and fentanyl 1 µg/kg was given for analgesia.
      Cisatracurium 0.15 mg/kg IV was given to facilitate direct laryngoscopy and orotracheal
      intubation. The patient was ventilated at tidal volume 6-8mL/kg and respiratory rate that
      achieved ETCO2 of 30-35 mmHg. Oropharyngeal pack was inserted.

      Anesthesia was maintained by isoflurane based on MAC 1.2 % until a steady state of anesthesia
      was achieved (defined as a state of anesthesia when no changes in hemodynamic variables take
      place for at least 10 min). An increase of ≥ 20% of basal value in both HR and MAP was
      treated with increasing the concentration of isoflurane by 0.5% and increments of fentanyl 1
      μg/kg. Muscle relaxation was confirmed by cisatracurium 0.03mg/kg every 20 mins. IV lactated
      ringer solution was infused at approximately 6ml/kg/hr till the end of the procedure.

      All patients were positioned supine and the bed-head of the surgical table was raised by 30°
      to improve venous drainage.

      Before the beginning of surgical procedure, well wrung out cotton pledgets soaked with 4 ml
      of 2% lignocaine with 1:200,000 adrenaline were topically applied to the nasal mucous
      membrane for 10 min (no infiltration).

      Technique for hemodynamic optimization:

      Target mean arterial pressure (MAP) was 60-70 mmHg during the surgical procedure to achieve
      Fromm and Boezaart category scale of 2 or 3 which is judged to be optimal for surgery (20).

      If the MAP was still ˃70mmHg in spite of increasing isoflurane inhalation to 2.5%,
      nitroglycerine (1-10 μg/kg/min.) titrated to effect.

      If the heart rate was more than 100 beats/ minute, propranolol was titrated 1-3 mg/hour to
      achieve target MAP.

      If mean arterial pressure (MAP) decreased to less than 60 mm Hg, ephedrine in increments of 3
      mg was given.

      Withdrawal vasoactive agents:

      After recording the surgeons' opinion regarding the surgical field and about 15 minutes
      before ending surgery, the infusion of any vasoactive medication (if used) was stopped and
      the anesthetic agent was decreased allowing HR and MAP to return to their basal value. If
      Hypotension (defined as SAP< 90mmHg and bradycardia less than 60 bpm) persisted, they was
      treated by ephedrine in increments of 3 mg .

      On compilation of surgical procedure, anesthesia was discontinued and reversal of
      neuromuscular blockade was achieved using IV neostigmine 0.08 mg/kg and atropine 20µg/kg.
      After removal of oropharyngeal pack, oropharyngeal suction was performed. On the start of
      obeying commands, patients were extubated and shifted to recovery room.

      Patients were discharged to the ward after reaching a score ≥ 9 on the Modified Aldrete
      Scoring System.

      During postoperative period up to 6 hours, the patient was monitored for conscious level,
      oxygen saturation, heart rate and mean arterial blood pressure.

      On ward admission, IM diclofenac sodium 75mg was given then every 12 hours. If the patient
      complained moderate to severe pain (VAS≥ 4) meperidine 25mg increments up to pain relief
      (maximum 100mg as a single dose) was given.
    

Intervention name(s): Gabapentin1200 mg; bisoprolol 2.5mg; placebo
Intervention type(s): Drug; Drug; Drug
Intervention description(s): patients received 1200mg gabapentin 2 hrs preoperative; patients received 2.5mg bisoprolol 2 hrs preoperative; patients received oral placebo 2 hrs preoperative
Other intervention name(s): gaptin; concor; vitamins
Intervention MeSH terms: Bisoprolol; Gabapentin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Treatment
Keywords: gabapentin; bisoprolol; hemodynamic; surgical field