Midazolam Versus Dexamethasone-ondansetron in Preventing Postoperative Nausea-vomiting for Laparoscopic Surgeries
Condition: Postoperative Nausea and Vomiting
MeSH terms: Nausea; Vomiting; Postoperative Nausea and Vomiting
Study type: Interventional

Summary: 
      Postoperative nausea and vomiting(PONV) affects 11 to 60 % of patients undergoing surgery and
      is a major cause of postoperative morbidity. Risk factors include female gender, non smokers,
      postoperative use of opioids and a past history of PONV. The simplified Apfel risk score is
      used to identify patients at risk for PONV. PONV prophylaxis is provided intraoperatively to
      patients with 2 or more risk factors. In spite of numerous drugs available, control of PONV
      remains a difficult task. Midazolam is a commonly used drug perioperatively for its
      anxiolytic and sedative properties. It decreases analgesic requirement and has also been
      found to have an antiemetic effect. This present study is designed to compare the
      prophylactic use of iv midazolam with a commonly used combination of
      dexamethasone-ondansetron in high risk patients (as defined by the modified Apfel score)
      undergoing laparoscopic surgeries.
    

Detailed description: 
      After Institutional Ethical Committee approval and written informed consent, 120 adult
      patients will be recruited for the study if they satisfy the inclusion and exclusion criteria
      as mentioned later. Consent will be obtained from the patients themselves. Standard protocol
      for administration of anaesthesia will be followed in all patients which is briefly
      described. All patients will receive general anaesthesia and will be induced with Propofol
      titrated to effect. Intraoperatively, isoflurane will be used as maintenance agent and
      vecuronium or atracurium as non depolarizing muscle relaxant. For analgesia, patients will
      receive intraoperative fentanyl.

      For the purpose of the study, patients will be randomized into two groups depending upon a
      computer generated randomized sheet. Group A will receive 8mg of dexamethasone i.v. after
      anaesthesia induction and 4 mg of ondansetron i.v. 30 minutes prior to the end of surgery.
      Patients in Group B will be administered 2 mg of midazolam i.v. 30 minutes prior to the end
      of surgery. Time to achieve Post anaesthesia discharge score( PADSS) of ≥9 will be noted.
      Patients will be asked to report any incidence of nausea, retching or vomiting for the first
      24 hours after surgery. The incidence of PONV and the amount of rescue antiemetic received
      will be noted at 2 hours and at 24 hours postoperatively. PONV will be scored based on the
      PONV Impact Scale score questionnaire (mentioned in the proforma)12. Rescue antiemetics will
      be administered in case the patient complains of PONV in accordance with American society of
      anesthesiologists (ASA) guidelines. The first line of rescue in Group A will be 10 mg of iv
      metaclopromide. Antihistaminics will be the second line of rescue antiemetic. In group B the
      first line of antiemetic will be 4 mg of ondansetron i.v. 10 mg of iv metaclopromide will be
      second line of rescue drug.

      Study period : It is estimated that the study will be completed within one year Sample size
      Assuming a reduction in 45 % in the incidence of PONV, with α error of 0.05 and β of 0.02, we
      would require 60 patients in each group i.e. a total of 120 patients.13 Intervention: For
      administration of PONV prophylaxis, patients will be randomized into two groups depending
      upon a computer generated randomized sheet. Group A will receive 8mg of dexamethasone i.v.
      after anaesthesia induction and 4 mg of ondansetron i.v. 30 minutes prior to the end of
      surgery. Patients in Group B will be administered 2 mg of midazolam i.v. 30 minutes prior to
      the end of surgery.

      Monitoring and assessment: Patients will be monitored 24 hours post operatively. Any
      complaints of nausea and/vomiting will be noted and rescue antiemetic will be administered as
      per the guidelines
    

Intervention name(s): Normal saline, Midazolam; Dexamethasone, ondansetron
Intervention type(s): Drug; Drug
Intervention description(s): 2 cc normal saline i.v. after anaesthesia induction.2 mg of injection midazolam intravenous 30 minutes prior to the end of surgery; 8mg of dexamethasone i.v. after anaesthesia induction and 4 mg of ondansetron i.v. 30 minutes prior to the end of surgery.
Intervention MeSH terms: Dexamethasone; Midazolam; Ondansetron
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: Single (Care Provider)
Primary purpose: Prevention
Keywords: Postoperative Nausea and Vomiting; Dexamethasone; Ondansetron; Midazolam; Laparoscopy; High risk