Postoperative nausea and vomiting

Postoperative nausea and vomiting
Classification and external resources
MeSH	D020250

Postoperative nausea and vomiting (PONV) is an unpleasant complication affecting about a third of the 10% of the population undergoing general anaesthesia each year. A 2008 study compared 121 Japanese patients who experienced PONV after being given the general anesthetic propofol to 790 people who were free of post-operative nausea after receiving it. Those with a G at both copies of rs1800497 were 1.6 times more likely to experience PONV within six hours of surgery compared to those with the AG or AA genotypes. But they were not significantly more likely to experience PONV more than six hours after surgery.^[1]

Impact

On average the incidence of nausea or vomiting after general anesthesia ranges between 25 and 30% [Cohen 1994]. Nausea and vomiting can be extremely distressing for patients and is therefore one of their major concerns [Macario 1999]. Vomiting has been associated with major complications such as pulmonary aspiration of gastric content and might endanger surgical outcomes after certain procedures, for example after maxillofacial surgery with wired jaws. Nausea and vomiting can delay discharge and about 1% of patients scheduled for day surgery require unanticipated overnight admission because of uncontrolled postoperative nausea and vomiting.

Management

Because no currently available antiemetic is especially effective by itself, and successful control is often elusive, experts recommend a multimodal approach. Anaesthetic strategies to prevent vomiting include using regional anaesthesia wherever possible and avoiding emetogenic drugs. Pharmacological treatment and prevention of postoperative nausea and vomiting is limited by both cost and the adverse effects of drugs. Patients with risk factors probably warrant prophylaxis, whereas a "wait and see" strategy is appropriate for those without risk factors.

In conjunction with antiemetic medications, at least one study has found that application to the Pericardium Meridian 6 accupressure point produced a positive effect in relieving postoperative nausea and vomiting.^[2] Another study found no statistically significant difference.^[3]

Continuous Wound Infiltration may reduce PONV and the need for post-operative pain management drugs.

A Cochrane review of 737 trials including 263 with ondansetron and 158 with metoclopramide indicated at most 80/100 surgical patients will experience Post Operative Nausea and Vomiting (PONV), if all are treated prophylactically 28 will benefit and 72 will not. post-operative patients treated prophylactically with Ondansetron experienced vomiting with a relative risk (RR) of 1.13 (95% CI(1.02-1.26)) Nausea or Vomiting RR 1.39 (95%CI (1.08-1.79)) Risk of vomiting after treatment with smaller doses of Metoclopromide RR 1.82(95% CI(1.16-2.87)) but this disappeared after doubling the dose of Metoclopramide.^[4]

Pharmacology

The introduction of the 5HT₃ receptor antagonist, ondansetron, in the early 1990s was a significant breakthrough. Despite the many studies, however, the evidence base to support rational antiemetic treatment remains patchy. Recent research has led to better understanding of some older drugs and has demonstrated that combinations of drugs are often useful. While the efficacy of droperidol is now clear, metoclopramide, a popular antiemetic for decades, was found to have limited efficacy at the lower traditional dosage. Some older drugs, such as haloperidol and hyoscine remain inadequately studied.

Emetogenic drugs commonly used in anaesthesia include nitrous oxide, physostigmine and opioids. The intravenous anaesthetic propofol is currently the least emetogenic general anaesthetic.

Risk factors

Postoperative nausea and vomiting results from anaesthesic, surgical, and patients factors. Gynaecological, urological, strabismus correction and middle ear surgery all have a higher risk of postoperative nausea and vomiting.

Patients that are female or who have a history of postoperative nausea and vomiting are at greater risk. Smokers have a decreased risk, but this would never be recommended by any physician. Older patients suffer less PONV.

Obesity, age less than 16 years, past history of motion sickness and high levels of pre-operative anxiety are also risk factors for PONV.

References

↑
↑ "Accupressure Treatment For The Prevention Of Postoperative Nausea And Vomiting".
↑ "Effect of acupressure on postoperative nausea and vomiting in laparoscopic cholecystectomy.".
↑ Carlisle, John; Stevenson, Carl (19 July 2006). "Drugs for preventing postoperative nausea and vomiting". The Cochrane Library. |accessdate= requires |url= (help)

Cohen MM, Duncan PG, DeBoer DP, Tweed WA. The postoperative interview: assessing risk factors for nausea and vomiting. Anesth Analg 1994;78:7-16.

Macario A, Weininger M, Carney S, Kim A. Which clinical anesthesia outcomes are important to avoid? The perspective of patients. Anesth Analg 1999:89(9):652-8

Tramèr MR. Treatment of postoperative nausea and vomiting. BMJ 2003;327:762-3. Fulltext. PMID 14525850.

Gan TJ: Risk factors for postoperative nausea and vomiting. Anesth Analg. 2006 Jun;102(6):1884-98. Review. PMID 16717343

PONV acronym

Anesthesia (outline)

Types	General Spinal Epidural Conduction anesthesia Local Topical Intercostal nerve block Sedation / Twilight anesthesia Dental (Inferior alveolar nerve) Neuroleptanalgesic anesthesia

Techniques	Airway management Anesthesia provision in the US Arterial catheter Bronchoscopy Capnography Dogliotti's principle Drug-induced amnesia Intraoperative neurophysiological monitoring Nerve block Penthrox inhaler Tracheal intubation

Scientific Principles	Blood–gas partition coefficient Concentration effect Fink effect Minimum alveolar concentration Second gas effect

Measurements	ASA physical status classification system Baricity Bispectral index Direct Fick method Entropy monitoring Fick principle Goldman index Guedel's classification Mallampati score Neuromuscular monitoring Thyromental distance

Instruments	Anaesthetic machine Anesthesia cart Boyle's machine Gas cylinder Laryngeal mask airway Laryngeal tube Medical monitor Odom's indicator Relative analgesia machine Vaporiser Double-lumen endotracheal tube Endobronchial blocker

Drugs	Benzodiazepine Etomidate General anaesthetic Inhalational anaesthetic Infiltration analgesia Ketamine Local anesthetic Methohexital Methoxyflurane Midazolam Neuraxial blockade Opiate Propofol Thiopental Thiopentone

Complications	Emergence delirium Allergic reactions Anesthesia awareness Local anesthetic toxicity Malignant hyperthermia Perioperative mortality Postanesthetic shivering Postoperative nausea and vomiting Postoperative residual curarization

Fields of study	Cardiothoracic Geriatric Oral sedation dentistry

Professions	Anesthesiologist Anesthesiologist assistant Nurse anesthetist Operating Department Practitioners Certified Anesthesia Technician Certified Anesthesia Technologist Anaesthetic technician

History	A.C.E. mixture Helsinki Declaration for Patient Safety in Anaesthesiology History of general anesthesia History of neuraxial anesthesia History of tracheal intubation

Organizations	American Association of Nurse Anesthetists American Society of Anesthesia Technologists & Technicians American Society of Anesthesiologists Anaesthesia Trauma and Critical Care Association of Anaesthetists of Great Britain and Ireland Association of Veterinary Anaesthetists Australian and New Zealand College of Anaesthetists Australian Society of Anaesthetists International Anesthesia Research Society