Understanding Postoperative Nausea

Postoperative Nausea is among the most common yet serious side effects associated with surgical procedures and general anesthesia.    Besides being an unpleasant feeling, Postoperative Nausea is associated with an increase in medical costs due to delayed discharge, delayed recovery, increased clinical complications, unanticipated admissions to the hospital, and significant impact on quality of life.

Up to 80% of all patients that undergo surgery experience Postoperative Nausea and Vomiting1.  Approximately 50% of these surgical patients experience Post Discharge Nausea and Vomiting, within 96 hours of the procedure2,3.

Recent studies suggest that despite currently available medications, patients consider Post Discharge Nausea and Vomiting among the most objectionable of all negative effects of surgery, even more than pain.

Understanding Postoperative Nausea Graph

These studies also suggest that patients are willing to pay more to avoid nausea and vomiting than any other side effect. In support of prevalence of Post Discharge Nausea and Vomiting, 24% of the re-admissions of surgical patients back into hospitals and emergency rooms are as result of Post Discharge Nausea and Vomiting.
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What Causes Emesis (Nausea & Vomiting)

Emesis is a complex process that can be triggered by a multitude of biological and physical pathways. Serotonin (5HT3), dopamine (D2), and substance P (SP) (which acts on the neurokinin, NK1. receptors) are believed to play the biggest role in the pathogenesis of NV.

When certain neuroreceptors are stimulated in response to varying types of stimulus they send impulses to the brainstem emetic control center located within the medulla oblongata which sits in the brainstem. For example, in the case of GI tract damage, neuroreceptors are stimulated and send signals for neurotransmitter release in the brainstem emetic control center.

The brainstem emetic control center consists of 3 closely related structures in the medulla oblongata:

  • Nucleus tractus solitarii
  • Area postrema/chemoreceptor trigger zone (CTZ)
  • Dorsal motor nucleus of the vagus nerve

The brainstem emetic control center coordinates the actions in the body that eventually result in emesis. This center can receive stimuli from both peripheral and central afferents within the nervous system. It also coordinates efferent output to the abdominal muscles that culminates in the physical act of vomiting.

Emesis signals are consolidated in the dorsal vagal complex.  Within this area, the signals activate the abdominal muscles, diaphragm, stomach and esophagus to produce an emetic reaction.
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Impact on Patients

The prominent role of Postoperative Nausea in reducing a patient’s quality of life and health has been widely documented in numerous clinical conditions. Despite the significant pharmacological advancements brought by the new 5-HT3 class of antiemetic, Postoperative Nausea often remains poorly controlled especially with oral therapy.

Besides being an unpleasant feeling, Postoperative Nausea is associated with an increase in medical costs due to delayed discharge, delayed recovery, increased clinical complications, unanticipated admissions to the hospital, and significant impact on quality of life.

A significant risk to the patient is the powerful muscular contractions associated with nausea and vomiting that could result in complications to the surgical site, which could lead to increased risk of bleeding, and other negatives outcomes resulting in complications to the patient.

There is also a possibility of the regurgitation of stomach contents, leading to risks of respiratory obstruction, pulmonary inflammation and aspiration pneumonia.  Electrolyte imbalance and dehydration can occur if Postoperative Nausea is severe, which can be an issue with young children3.

In addition, the currently available pharmacological agents have many side effects and potential for significant for drug-on-drug interactions and comorbidities. As such, for both care givers and patients, Postoperative Nausea can have a serious effect on numerous clinical treatments and outcomes.

There are a number of well defined risk factors which can increase significantly increases a patient’s chances of experiencing Postoperative Nausea.

Surgical Procedures:

  • Laparoscopic (Intra abdominal)
  • Bariatric
  • Gynecological (non D&C)
  • Gastrointestinal
  • Ear, Nose, Throat
  • Reconstructive/Plastic
  • Ophthalmic
  • Breast Augmentation/Reduction
  • Neurosurgery
  • Orthopedic
  • Cardiothoracic

Patient Risk Factors:

  • Female
  • Non-smoker
  • History of motion sickness
  • History of post-op nausea
  • Obesity
  • Pre-adolescent
  • Anxiety
  • History of migraines
  • Pain

Other Risk Factors:

  • Use of Opiod Anesthetic
  • Duration of Anesthsia (greater than 60 mins)

Apfel CC et al. Anesthesiology. 1999; 91; 693-700
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Economic Cost

Despite intervention, Postoperative Nausea and Vomiting / Post Discharge Nausea and Vomiting remain a problem that cannot be adequately managed with current available options. Postoperative Nausea and Vomiting / Post Discharge Nausea result in the need for additional monitoring and treatment. Postoperative Nausea and Vomiting / Post Discharge Nausea can result in costs associated with additional time in the post anesthesia care unit (PACU), additional (rescue) medication; materials cost hospitalization and readmission/re-hospitalization.
Sanchez et al., in 1995, estimated the costs of Postoperative Nausea and Vomiting / Post Discharge Nausea to be $1,055 in total and that if an institution conducted 100 procedures per month, a rate of Postoperative Nausea and Vomiting of 30% the cost to the hospital for a year would be $380,000 and at 300 procedures per month it could exceed $1 million4.
Pan et al. found that PACU time increased by an average of 27 minutes due to Postoperative Nausea and Vomiting in patients treated only with 4mg ondansetron during anesthesia vs. those treated with dexamethasone 8mg and 4mg of ondansetron during anesthesia5. In addition those patients in the control group had a higher incidence of nausea (73% vs 57%), emesis (23% vs. 10%) and rescue medication (40% vs. 27%) over a 120 hour period postdischarge.5

In evaluating laparoscopic cholecystecomy, Lau and Brooks for a rate of unanticipated hospitalization associated with Postoperative Nausea and Vomiting to be approximately 1 percent6. Others have estimated the unanticipated admission rate as high as 2 percent from Postoperative Nausea and Vomiting7.
Hill et al identified several components of cost associated with postoperative emesis and postoperative nausea including7:

  • Rescue antiemetic
  • Materials cost
  • Personnel (MD and PACU time)
  • PACU delay
  • Hospital admission

The average cost of treating emesis was $303 and the average cost of treating nausea was $827. The two largest cost components were personnel (83%) and hospital admission (10%). In addition, with 1 to 2 percent of patients being readmitted for Postoperative Nausea and Vomiting / Post Discharge Nausea, it is necessary to explore the cost of the readmission in terms of rescue medication costs, ER costs and hospital days as those costs may not be reimbursed under the global period of the surgery, with a growing trend to expand and not pay for any re-admission associated with a surgical event.
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1.Gan TJ, Meyer T, Apfel CC, et al.  Concensus guidelines for managing postoperative nausea and vomiting.  Anesth Analg.  2003; 97:62-71Pan et al. Antiemetic Prophylaxis for Postdischarge Nausea and Vomiting and Impact on Functional Quality of Living During Recovery in Patients with High Emetic Risks: A prospective, Randomized, Double-Blind Two Prophylactic Antiemetic Regimens. Ambulatory Anesthesiology. V107 (2) Aug 2008: 429-438.

2. Gan TJ, Meyer T, Apfel CC, et al. Postoperative nausea and vomiting – can it be eliminated? JAMA. 2002;287:1233-1236.  

3. Carroll NV, Miederhoff P, Cox FM, Hirsch JD.  Postoperative nausea and vomiting after discharge from outpatient surgery centers. Anesth Analg. 1995; 80:903-909.

4.Sanchez et al.  Estimation of the Cost of Postoperative Nausea and Vomiting in an Ambulatory Surgery Center.  Journal of Research in Pharmaceutical Economics.  V 6,(2), 1995, 35 – 44.

5.Pan et al.  Antiemetic Prophylaxis for Postdischarge Nausea and Vomiting and Impact on Functional Quality of Living During Recovery in Patients with High Emetic Risks: A  prospective, Randomized, Double-Blind  Two Prophylactic Antiemetic Regimens.  Ambulatory Anesthesiology.  V107 (2) Aug 2008: 429-438.

6.Lau and Brooks.  Predictive Factors of Unanticipated Admissions After Ambulatory Laparoscopic Choleycystecomy.  Archives of Surgery.  V136.  Oct 2001: 1150-1153.
7.Hill et al.  Cost-effectiveness of Prophylactic Antiemetic Therapy with Ondansetron, Droperidol, or Placebo.  Anesthesiology.  V92. Apr 2000: 958-967