Effect of Total Intravenous Anaesthesia With Propofol on Postoperative Pain After Bilateral Third Molar Surgery
Condition: Postoperative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional
Phase: Phase 4

Summary: 
      Propofol is one of the most commonly used intravenous anaesthetic drugs both for induction
      and maintenance of general anaesthesia. Some of the advantages of total intravenous
      anaesthesia (TIVA) with propofol include reduced nausea and vomiting, reduced atmospheric
      pollution, better wake up profile and a more favourable intracranial physiology. However, the
      need for a reliable intravenous access, specialized pumps, pain on injection and potential
      concerns regarding awareness are some reasons that preclude more common use.

      Postoperative dental pain produces an inflammatory pain model. Since propofol has
      anti-inflammatory effects, it may have significant analgesic effects in patients undergoing
      dental surgery. To the best of our knowledge, there are no randomized controlled trials
      comparing the effects of TIVA propofol and inhalational anaesthetic on postoperative dental
      pain. The aim of this study is to investigate the effect of TIVA propofol on postoperative
      pain scores, analgesic consumption, and adverse effects in patients undergoing dental
      surgery. This will help determine whether propofol may be a useful analgesic adjunct in
      dental surgery.
    

Detailed description: 
      Preoperative care

      Assessment will be done at the preadmission clinic or at the general ward. Fasting for
      patients will start at midnight before operation. Sedative premedication will not be
      prescribed.

      Anaesthesia and intraoperative care

      Group S

      Patients from group S will be anaesthetized according to the following protocol:

      On arrival to the operation theatre, a 20 or 22 gauge intravenous cannula will be inserted.
      Standard monitoring with pulse oximeter, non-invasive blood pressure, and three lead
      electrocardiogram will be applied prior to induction. Non-invasive blood pressure will be
      checked at least every 5 minutes throughout the operation.

      Propofol 1.5-3mg/kg, remifentanil 0.5-1mcg/kg, and rocuronium 0.6-1mg/kg or atracurium
      0.5mg/kg will be used intravenously (IV) for induction of general anaesthesia. Otrivin can be
      applied nasally at the discretion of the anaesthetist. Intubation would be performed after
      induction of general anaesthesia. General anaesthesia monitoring will be used. Sevoflurane,
      air and oxygen will be used for maintenance of general anaesthesia. FiO2 will be kept between
      35-50%. BIS monitoring will be applied and level of anaesthetia will be titrated to keep a
      BIS value of 40-60. Intravenous remifentanil infusion between 0.1-0.25mcg/kg/min will be
      given and this will be titrated to optimal haemodynamic parameters. Muscle relaxants can be
      given during the operation as required.

      Intravenous phenylephrine, ephedrine or fluid administration with colloid or crystalloid will
      be given at the discretion of the anaesthesiologist for management of hypotension.
      Hypertension or tachycardia will be managed by titrating the remifentanil infusion up to
      0.25mcg/kg/min or sevoflurane up to 1.5 MAC. Intravenous anti hypertensive agents such as
      beta blockers (eg. esmolol, labetolol), hydralazine, glyceryl trinitrate, and phentolamine
      can be given if hypertension persists.

      Thermal blanket will be used with the aim of keeping a core temperature of 35.5-37.5 degrees
      Celsius. Ondansetron 4mg IV can be given 30 minutes before end of surgery.

      Sevoflurane and remifentanil infusion will be switched off at the end of the procedure.
      Reversal of muscle relaxation can be obtained if required with neostigmine 50mcg/kg IV and
      atropine 20mcg/kg IV after the operation. Patients will subsequently be transferred to the
      post anaesthetic care unit (PACU) for monitoring for at least 30 minutes.

      Group P

      Patients in group P will be anaesthetized according to the following protocol:

      Monitoring and other anaesthetic procedures including the management of hypertension and
      hypotension will be the same as group S. The only difference is that induction and
      maintenance of general anaesthesia will be conducted using total intravenous infusion of
      propofol. Sevoflurane will not be used, and oxygen and air would be given to provide a FiO2
      of 30-50%.

      Target controlled infusion (TCI) with modified Marsh effect site model (Fresenius Kabi) will
      be used for induction and maintenance of general anaesthesia. Level of anaesthesia will be
      titrated to produce a BIS value of between 40-60. As with patients in group S, remifentanil
      will be infused at a rate of between 0.1-0.25mcg/kg/min.

      Analgesic modalities and pain assessment

      Both groups (Groups S and P)

      Dental surgeon will provide local infiltration with 2.7ml of 2% lignocaine with 1:80,000
      adrenaline around the base of the gum of each third molar tooth. Morphine sulphate at a bolus
      dose of 0.025-0.075 mg/kg will be given intravenously before skin incision.

      Resting pain scores will be checked every 5 minutes in the post anaesthetic care unit. 2mg
      boluses of intravenous morphine sulphate will be given every 5 minutes until the NRS pain
      score is less than 4/10. Respiratory rate, oxygen saturation, Ramsay sedation scores, blood
      pressure and heart rate will be monitored every 5 minutes while the patient is in the post
      anaesthetic care unit.

      When the patient resumes fluid diet on postoperative day 0, oral paracetamol 500mg q6h and
      oral dihydrocodeine 30mg q6h will be prescribed on an as needed basis when NRS pain score is
      more than 3/10 for three days. Both analgesics will be given together.

      In the ward, pain related parameters like the numerical rating scales (NRS) pain scores at
      rest and mouth opening, and side effects will also be recorded every 1 hour for 6 hours, and
      then once every 4 hours. Patients will be given a diary to record NRS pain scores at rest and
      with mouth opening, analgesic consumption, and side effects at 24th, 48th and 72nd hour after
      operation. Global pain satisfaction using a scale of 0-10 (0 being least satisfied and 10
      being most satisfied) will be recorded on postoperative day 3.

      Monitoring of vital signs will be at the discretion of the attending dental surgeon once the
      patient returns to ward, and final hospital discharge will also be determined by the
      attending dental surgeon.

      A brief home telephone interview will be conducted at 3 months to assess the incidence of
      chronic pain. The severity of pain, if present, would be recorded using NRS at rest and on
      mouth opening from 0-10.
    

Intervention name(s): propofol; Sevoflurane
Intervention type(s): Drug; Drug
Intervention description(s): Monitoring and other anaesthetic procedures including the management of hypertension and hypotension will be the same as group S. The only difference is that induction and maintenance of general anaesthesia will be conducted using total intravenous infusion of propofol. Sevoflurane will not be used, and oxygen and air would be given to provide a FiO2 of 30-50%.; Propofol 1.5-3mg/kg, remifentanil 0.5-1mcg/kg, and rocuronium 0.6-1mg/kg or atracurium 0.5mg/kg will be used intravenously (IV) for induction of general anaesthesia. Otrivin can be applied nasally at the discretion of the anaesthetist. Intubation would be performed after induction of general anaesthesia. General anaesthesia monitoring will be used. Sevoflurane, air and oxygen will be used for maintenance of general anaesthesia. FiO2 will be kept between 35-50%. BIS monitoring will be applied and level of anaesthetia will be titrated to keep a BIS value of 40-60. Intravenous remifentanil infusion between 0.1-0.25mcg/kg/min will be given and this will be titrated to optimal haemodynamic parameters. Muscle relaxants can be given during the operation as required.
Intervention MeSH terms: Propofol; Sevoflurane
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Patients in the first group (S) will be anaesthetized by inhalational anaesthesia using sevoflurane. The patients in the second group (P) will be anaesthetized using total intravenous propofol.
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: postoperative pain; propofol; TIVA