Nausea and vomiting are common complaints in humans. The severity of the event can range from a slight discomfort or queasiness to uncontrollable, forceful vomiting. Despite this range of symptoms, all are perceived to be uncomfortable and troublesome and should be treated in a proper and timely manner. Patients may refer to this experience by many different names: upchuck, urp, queasy, throw up, and puke, to name a few. There are many different causes of nausea and vomiting, such as motion sickness, pregnancy, and medications. Likewise, many treatment options can be used to manage this complication. People of all ages experience emesis, although the etiology may be related to age-specific factors. Drugs are most frequently used for the treatment of nausea and vomiting, but alterations of nondrug factors may decrease the severity of emesis. This chapter reviews the pathophysiology and pharmacotherapy of specific types of nausea and vomiting.
There are multiple causes for nausea and vomiting; however, some of the most common are from the ingestion or administration of substances or drugs, gastrointestinal (GI) disorders, neurologic processes, and metabolic disorders. The presence of noxious stimuli is frequently a cause of nausea and vomiting. Supratherapeutic digoxin (Lanoxin) and theophylline (Theo-Dur or Slo-Phyllin) are known to produce emesis. Nausea and vomiting occur more frequently with high-dose chemotherapy than with moderate doses of the same drugs. Erythromycin and some penicillin derivatives are acknowledged for inducing uncomfortable GI complications. Emesis can also result from excessive ethanol intake. It is well known that other sensory experiences, such as pungent odors or gruesome sights, can induce nausea and vomiting. Box 28.1
presents specific etiologies for nausea and vomiting.
Patient-specific factors that increase susceptibility to nausea and vomiting include age, previous nausea and vomiting experiences, and sex. Most of the research identifying these characteristics was done in patients receiving chemotherapy. Poor control of nausea and vomiting with previous surgeries or chemotherapy predisposes a patient to subsequent episodes of emesis, also referred to as anticipatory nausea and vomiting. This form of emesis is often difficult to treat with standard antiemetics drug therapy.
Patients who receive previously received chemotherapy have been noted to experience emesis compared to those who are chemotherapy naive. Additionally, younger female patients are noted to have a greater risk of emesis (Hesketh, 2008
). Surprisingly, patients who have higher chronic ethanol intake exceeding 100 g/d (roughly 5 beers or mixed drinks per day) are associated with better emesis control and decreased incidence of vomiting. A history of motion sickness may increase the risks of nausea and vomiting in another situation, such as with chemotherapy or surgery. Children in general experience nausea and vomiting more frequently than do adults. Obesity and anxiety have also been associated with heightened emesis incidence (Hesketh, 2008
The prevalence of nausea and vomiting may complicate 20% to 70% of surgical procedures (Gan, 2008
). Prevalence is also increased by the use of certain inhalation agents (nitrous oxide, in particular) and by concomitant use of opiate medications; the use of propofol as an intravenous anesthetic agent lowers the risk of postoperative nausea and vomiting (PONV). PONV is more likely to occur after general than regional anesthesia, and its prevalence increases in parallel with the duration of surgery and anesthesia. PONV is especially common
after gynecologic and middle ear surgery and also occurs more commonly with abdominal and orthopedic surgery than with laparoscopic or other extra-abdominal operations. PONV is also more likely in those with a history of PONV or motion sickness.
The three identified phases of emesis are nausea, retching, and vomiting. Nausea is the unpleasant physical sensation of impending retching or vomiting. Nausea often occurs without the other two steps of emesis, although they are all treated with the same pharmacologic agents. Common symptoms accompanying nausea are flushing, pallor, tachycardia, and hypersalivation. Gastric stasis, decreased pyloric tone, mucosal blood flow, and contractions of the duodenum with reflux into the stomach are physiologic responses to nausea. Retching, the second phase of emesis, is the involuntary synchronized labored movement of abdominal and thoracic muscles before vomiting. Vomiting is the coordinated contractions of the abdominal and thoracic muscles to expel the gastric contents. The lower esophageal sphincter contracts, allowing GI retroperistalsis. The actual expulsion of gastric contents differentiates vomiting from retching.
The acuteness of the symptomatology is based on history and physical examination. Several issues need to be addressed such as whether this is an acute emergency, such as mechanical obstruction, perforation, or peritonitis, clinical clues that the problem is likely to be self-limited, such as would be expected with viral gastroenteritis or a potentially offending medication. The goal is to determine whether empiric treatment with an antiemetic, a gastric acid-suppressing, or a prokinetic agent would be beneficial or whether the patient should be admitted to the hospital to correct fluid and electrolyte imbalance.
Acute nausea and vomiting differs considerably from that of chronic nausea and vomiting differing in symptom duration. Acute onset of nausea and vomiting suggests gastroenteritis, pancreatitis, cholecystitis, or a drug-related side effect. When nausea and vomiting are associated with diarrhea, headache, and myalgias, the cause is viral gastroenteritis; in this instance, symptoms should resolve spontaneously within 5 days. A more insidious onset of nausea without vomiting is suspicious of gastroparesis, a medication-related side effect, metabolic disorders, pregnancy, or even gastroesophageal reflux disease. Nausea and vomiting are considered chronic when their duration is longer than 1 month.
Timing and description of the vomiting are important. Vomiting that occurs in the morning before breakfast is typical of that related to pregnancy, uremia, alcohol ingestion, and increased intracranial pressure. Projectile vomiting suggests intracranial disorders, especially those that result in increased intracranial pressure. In this case, vomiting may not be preceded by nausea.
The onset of vomiting caused by gastroparesis or gastric outlet obstruction tends to be delayed, usually by more than 1 hour, after meal ingestion. Vomiting may be suggestive of psychiatric disorders.
Associated symptoms such as abdominal pain, fever, diarrhea, vertigo, or a history of a similar contemporaneous illness among family, friends, or associates are important data to gather.
The physical examination looks at vital signs for signs of dehydration. Jaundice, lymphadenopathy, abdominal masses, and occult blood in the stool may reveal features suggestive of thyrotoxicosis or Addison disease. The abdominal examination should look for distention, visible peristalsis, and abdominal or inguinal hernias. Areas of tenderness are important: tenderness in the midepigastrium suggests an ulcer, and in the right upper quadrant, cholecystitis or biliary tract disease. Auscultation may demonstrate increased bowel sounds in obstruction or absent bowel sounds in ileus.
The treatment of nausea, retching, or vomiting in any patient begins with an evaluation and correction of possible causes. Most sources of nausea and vomiting may be reversed or palliated by surgery or medical interventions. Infectious causes should be promptly treated with antibiotics, and metabolic disorders require medical management. Some drug toxicities may be treated with antidotes, such as digoxin toxicity reversed with digoxin immune Fab (Digibind). The following section discusses medications used to treat nausea and vomiting. They should be used with definitive treatments when possible.
Alterations in a patient’s daily activities may aid in managing nausea and vomiting and decrease the resources used to control the problem. Nonpharmacologic management of nausea and vomiting should be tailored to the presumed etiology.
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