Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effect of Intraoperative Anesthetic Management on Postoperative Nausea and Vomiting (PONV) in Bariatric Surgery
Brief Summary: Morbidly obese patients are at high risk for Postoperative Nausea and Vomiting (PONV) after surgery and general anesthesia. The results of our observational study indicate that 42.7% of patients require medication to treat PONV in the first 24 hours after bariatric surgery despite our aggressive perioperative approach with triple prophylaxis. Common risk factors for PONV are the use of intraoperative narcotics and anesthetic gases.

Preliminary results of multimodal postoperative analgesia in the first 24 hours lead to a reduction of narcotic consumption, desaturations and use of antiemetic medication.

Our study hypothesis is that different types of anesthetics reduce PONV further.

Patient would be randomly assigned to receive either our current intraoperative management or a narcotic free, total intravenous general anesthetic (TIVA).

The investigators hope to improve patients' satisfaction by reducing PONV in the postoperative period.


Options:
A: Inclusion Criteria:

* Age more than 18 years
* Clinical need for sedation of an initially intubated (or tracheotomised) and ventilated (with inspiratory assistance) patient
* Prescribed light to moderate sedation (target RASS = 0 to -3) using propofol
* Patients should be randomised within 72 hours from ICU admission and within 48 hours of commencing continuous sedation in the ICU
* Patients should have an expected requirement for sedation more than 24 hours from time of randomisation
* Written informed consent must be obtained according to local regulations before starting any study procedures other than pre-screening

Exclusion Criteria:

* Acute severe intracranial or spinal neurological disorder due to vascular causes, infection, intracranial expansion or injury
* Uncompensated acute circulatory failure at time of randomisation (severe hypotension with mean arterial pressure \[MAP\] \< 55 mmHg despite volume and pressors)
* Severe bradycardia (heart rate \[HR\] \< 50 beats/min)
* AV-conduction block II-III (unless pacemaker installed)
* Severe hepatic impairment (bilirubin \> 101 µmol/l)
* Need for muscle relaxation at the time of randomisation (may only be used for intubation and initial stabilization)
* Loss of hearing or vision, or any other condition which would significantly interfere with the collection of study data
* Burn injuries requiring regular anaesthesia or surgery
* Use of centrally acting α2 agonists or antagonists at the time of randomisation, notably clonidine
* Patients who have or are expected to have treatment withdrawn or withheld due to poor prognosis
* Patients receiving sedation for therapeutic indications rather than to tolerate the ventilator (e.g. epilepsy)
* Patients who are unlikely to require continuous sedation during mechanical ventilation (e.g. Guillain-Barré syndrome)
* Patients who are unlikely to be weaned from mechanical ventilation e.g. diseases/injuries primarily affecting the neuromuscular function of the respiratory apparatus such as clearly irreversible disease requiring prolonged ventilatory support (e.g. high spinal cord injury or advanced amyotrophic lateral sclerosis)
* Distal paraplegia
* Positive pregnancy test or currently lactating
* Received any investigational drug within the preceding 30 days
* Concurrent participation in any other interventional study (any study in which patients are allocated to different treatment groups and/or non-routine diagnostic or monitoring procedures are performed)
* Previous participation in this study
* Any other condition which, in the investigator's opinion, would make it detrimental for the subject to participate in the study
B: Inclusion Criteria:

* Age 18 years and over
* Clinical need for sedation of an initially intubated (or tracheotomised) and ventilated (with inspiratory assistance) patient
* Prescribed light to moderate sedation (target RASS = 0 to -3) using midazolam infusion
* Patients should be randomised within 72 hours from ICU admission and within 48 hours of commencing continuous sedation in the ICU
* Patients should have an expected requirement for sedation of at least 24 hours from time of randomisation
* Written informed consent must be obtained according to local regulations before starting any study procedures other than pre-screening.

Exclusion Criteria:

* Acute severe intracranial or spinal neurological disorder due to vascular causes, infection, intracranial expansion or injury
* Uncompensated acute circulatory failure at time of randomisation (severe hypotension with MAP \< 55 mmHg despite volume and pressors)
* Severe bradycardia (HR \< 50 beats/min)
* AV-conduction block II-III (unless pacemaker installed)
* Severe hepatic impairment (bilirubin \> 101 µmol/L)
* Need for muscle relaxation at the time of randomisation (may only be used for intubation and initial stabilization)
* Loss of hearing or vision, or any other condition which would significantly interfere with the collection of study data
* Burn injuries requiring regular anaesthesia or surgery
* Use of centrally acting α2 agonists or antagonists at the time of randomisation, notably clonidine (see section 5.7 for prior and concomitant treatments)
* Known allergy to any of the study drugs or any excipients of the study drugs
* Patients who have or are expected to have treatment withdrawn or withheld due to poor prognosis
* Patients receiving sedation for therapeutic indications rather than to tolerate the ventilator (e.g. epilepsy)
* Patients unlikely to require continuous sedation during mechanical ventilation (e.g. Guillain-Barré syndrome)
* Patients who are unlikely to be weaned from mechanical ventilation; e.g. diseases/injuries primarily affecting the neuromuscular function of the respiratory apparatus such as clearly irreversible disease requiring prolonged ventilatory support (e.g. high spinal cord injury or advanced amyotrophic lateral sclerosis)
* Distal paraplegia
* Positive pregnancy test or currently lactating
* Received any investigational drug within the preceding 30 days
* Concurrent participation in any other interventional study (any study in which patients are allocated to different treatment groups and/or non-routine diagnostic or monitoring procedures are performed)
* Previous participation in this study
* Any other condition which, in the investigator's opinion, would make it detrimental for the subject to participate in the study
C: Inclusion Criteria:

* All patients scheduled for bariatric surgery at Flagler Hospital will be included after written and informed consent.

Exclusion Criteria:

* Patients will be excluded from the study if they don't consent to participate in the study. Patients allergic to any of the study medication will be excluded. Patients with second or third degree heart block will be excluded.
D: Inclusion Criteria:

1. Adult (≥18 years of age);
2. American Society of Anesthesiologists (ASA) score I - IV inclusive;
3. Male or female. If female, subject is non-lactating and is either:

   1. Not of childbearing potential, defined as post-menopausal for at least 1 year or surgically sterile due to bilateral tubal ligation, bilateral oophorectomy or hysterectomy.
   2. Of childbearing potential but is not pregnant at time of baseline and is practicing one of the following methods of birth control: oral or parenteral contraceptives, double-barrier method, vasectomized partner, or abstinence from sexual intercourse.
4. Requiring awake fiberoptic (oral or nasal) intubation because of anticipated difficult airway. Subjects must meet at least one of the criteria listed below:

   Criteria for Assessing Difficult Airways

   i. History of difficult intubation

   ii. Anticipated difficult airway
   1. Prominent protruding teeth
   2. Small mouth opening
   3. Narrow mandible
   4. Micrognathia
   5. Macroglossia
   6. Short, muscular neck
   7. Very long neck
   8. Limited neck extension
   9. Congenital airway anomalies
   10. Obesity
   11. Known airway pathology
   12. Known airway malignancy
   13. Upper airway obstruction

   iii. Trauma
   1. Face
   2. Upper airway
   3. Cervical spine

   iv. Anticipated difficult mask ventilation

   v. Severe risk of aspiration

   vi. Respiratory failure

   vii. Severe hemodynamic instability
5. Subject (or subject's legally authorized representative) must voluntarily sign and date the informed consent.

Exclusion Criteria:

1. Previous exposure to any experimental drug within 30 days prior to study drug administration;
2. Central nervous system (CNS) disease with an anticipated increased intracranial pressure or cerebrospinal fluid (CSF) leak;
3. Uncontrolled seizure disorder and/or known psychiatric illness that could confound a normal response to sedative treatment;
4. Presence of acute alcohol intoxication;
5. Current (within 14 days of study entry) treatment with an α2-agonist or antagonist;
6. Subject for whom benzodiazepines, dexmedetomidine or other α2-agonists are contraindicated;
7. Subject received an IV or oral (PO) opioid within one hour or intramuscularly within four hours of the start of study drug administration;
8. Subject has acute unstable angina, laboratory confirmed acute myocardial infarction within the past 6 weeks, heart rate \<50 bpm, systolic blood pressure (SBP) \<90 mmHg, or complete heart block unless they have a pacemaker.
9. Subject has elevated serum glutamic pyruvate aminotransferase/alanine transaminase (SGPT/ALT) and/or Serum glutamic oxaloacetic transaminase/ aspartate aminotransferase (SGOT/AST) values of ≥2 times the upper limit of normal (ULN).
10. Subject has any other condition or factor which, in the Investigator's opinion, might increase the risk to the subject.

Answer: C