Penehyclidine for Prevention of Nausea and Vomiting After Bimaxillary Surgery
Penehyclidine for Prevention of Nausea and Vomiting After Bimaxillary Surgery
Postoperative nausea and vomiting (PONV) is a common complication after surgery. Patients
 undergoing orthognathic surgery are reported to have a high rate of PONV, especially those
 undergoing bimaxillary surgery. Activation of cholinergic system plays an important role in
 the development of PONV. Penehyclidine is an muscarinic antagonists which selectively block
 M1 and M3 receptors and is commonly used to decrease oral secretion. The investigators
 hypothesize that continuously administrated penehyclidine during perioperative period can
 reduce the incidence of PONV in patients undergoing bimaxillary surgery.
Postoperative nausea and vomiting (PONV) is one of the most frequently occurred complications
 after surgery, and are associated with patients' dissatisfaction after anesthesia and
 surgery. Orthognathic surgery is widely performed for the correction of dentofacial
 deformities. Despite of improved anti-emetic prophylaxis, patients undergoing orthognathic
 surgery are reported to have a high incidence of PONV, especially those after bimaxillary
 surgery.

 It is known that activation of central cholinergic system plays an important role in the
 development of PONV. Muscarinic antagonists such as scopolamine can block muscarinic
 receptors in the cerebral cortex and produce anti-emetic effects. Penehyclidine is a new
 muscarinic antagonists which selectively block M1 and M3 receptors. Our previous study
 indicated that single-dose of penehyclidine injected before anesthesia induction was
 associated with a reduced risk of PONV during the first 6 h postoperatively.The mean
 elimination half-life of penehyclidine following single administration is about 10.35 h.
 Hence, a single-dose penehyclidine may only produce a short duration of antiemetic effect.

 The investigators hypothesize that continuously administrated penehyclidine during
 perioperative period reduces PONV more effectively than single-dose injection in patients
 undergoing bimaxillary surgery. The purpose of this study is to investigate the effect of
 continuous administered penehyclidine in preventing PONV in patients undergoing bimaxillary
 surgery.
Inclusion Criteria:

 1. Age ≥18 years but <60 years; body mass index ≥18 but <30 kg/m2;

 2. Scheduled to undergo elective bimaxillary surgery under general anesthesia;

 3. Planned to use patient-controlled intravenous analgesia (PCIA) after surgery;

 4. Provide written informed consents.

 Exclusion Criteria:

 1. Presence of glaucoma;

 2. Allergic to penehyclidine, atropine, scopolamine or other anticholinergic drugs;

 3. Acute or chronic nausea and/or vomiting, or gastrointestinal motility disorders before
 surgery;

 4. Preoperative antiemetic therapy within 12 hours;

 5. History of schizophrenia, Parkinson's disease or profound dementia, or language
 barrier;

 6. Severe hepatic dysfunction (Child-Pugh class C), severe renal dysfunction (requirement
 of renal replacement therapy before surgery) or American Society of Anesthesiologists
 physical status ≥IV.