Dual-dose Aprepitant to Reduce Postoperative Nausea and Vomiting After Laparoscopic Bariatric Surgery.

Postoperative nausea and vomiting (PONV) is unpleasant and increases health care costs. Despite modern techniques and prophylaxis, PONV rates remain high after laparoscopic bariatric surgery. We aim to reduce PONV after laparoscopic bariatric surgery using aprepitant with a similar scheme used for emetogenic chemotherapy.

Postoperative nausea and vomiting (PONV) is not only a disturbing and unpleasant experience for the patient, it also increases length of post anaesthesia care unit (PACU) and hospital stay. In addition, PONV increases the risk for unplanned admission, risk for complications and in the end, health care costs. Risk factors have been identified more than 20 years ago by Apfel et. al., whose screening score has been widely implemented to augment perioperative prophylaxis. But despite modern anaesthetic techniques and combined antiemetic prophylaxis, PONV rates remain high in patients at high risk for PONV: in a recent retrospective study in female patients after laparoscopic bariatric surgery, up to 68% suffered from PONV during the first 48 hours after surgery despite triple antiemetic prophylaxis. While aprepitant is prescribed for three consecutive days after chemotherapy, there is no study so far evaluating the effect of a second dose of aprepitant 24 hours after surgery to prevent the increase in PONV after PACU discharge. We hypothesise, that adding two scheduled doses of aprepitant (2 hours before and 24 hours after surgery) to a twofold antiemetic regimen will significantly reduce cumulative PONV in the first 48 hours after laparoscopic bariatric surgery in patients with moderate to high risk for PONV.

Eligibility Criteria:
Inclusion Criteria:

* Aged 18 and more
* Scheduled for an elective, laparoscopic bariatric surgery (either laparoscopic gastric sleeve resection or laparoscopic gastric bypass)
* BMI \> 30 kg/m2
* moderate to high risk for PONV (defined as APFEL score of 2 or higher)
* Informed Consent as documented by signature (see appendix 2).

Exclusion Criteria:

* emergency or open abdominal surgery;
* contraindication to aprepitant:

  * known allergy/hypersensitivity
  * on pimozide, terfenadine, astemizole or cisapride
* on regular medication with known interaction with the study drug:

  * benzodiazepines
  * ketoconazole, itraconazole
  * rifampicin, clarithromycin
  * paroxetine
  * diltiazem
  * carbamazepine, phenytoin
  * tolbutamid
  * ritonavir
  * St. John's wort
* patients with history of chronic nausea/vomiting or taking medication with known antiemetic properties (dexamethasone, metoclopramide, meclozine)
* severe hepatic impairment (Child-Pugh score \>9);
* chronic substance abuse (except smoking);
* significant psychiatric disease precluding interrogation;
* Inability to follow the procedures of the study, e. g. due to language barrier;
* Women who are pregnant or breast feeding;
* Intention to become pregnant during the course of the study and 2 months after surgery;
* Lack of safe contraception, defined as: Female participants of childbearing potential, not using and not willing to continue using a condom in addition to a medically reliable method of contraception for the entire study duration and 2 months after surgery, such as oral, injectable, or implantable contraceptives, or intrauterine contraceptive devices, or who are not using any other method considered sufficiently reliable by the investigator in individual cases. Female participants who are surgically sterilised / hysterectomised or post-menopausal for longer than 2 years are not considered as being of child bearing potential.
* male participants need to use a condom for the whole study period and 2 months after surgery;
* unable to consent, e. g. patients incapable of judgment needing next-of-kin consent or under tutelage;
* participation in another study with an investigational drug within the 30 days preceding and during the present study;
* previous enrolment into the current study;
* enrolment of the investigator, his/her family members, employees and other dependent persons.