A Quick Review of AFPs "Evaluation of Nausea and Vomiting"

A quick review of;
Evaluation of Nausea and Vomiting
KEITH SCORZA, MD, AARON WILLIAMS, DO, J. DANIEL PHILLIPS, MD, and JOEL SHAW, MD  Dewitt Army Community Hospital Family Medicine Residency, Fort Belvoir, Virginia
http://www.aafp.org/afp/2007/0701/p76.pdf
Am Fam Physician. 2007 Jul 1;76(1):76-84.
     All throw-up is not the same. Vomiting is the forceful expulsion of stomach contents through involuntary contractions. Regurgitation does not have the "forceful expulsion", but food does come back up.  Rumination is voluntary regurgitation. Nausea and vomiting (N/V) are symptoms that could mean a lot or nothing. The differential is three pages long in this article. Medications can cause N/V at onset. Common medications that cause N/V are chemotherapeutic agents, alcohol, antibiotics, opiates, anticonvulsants, digoxin, hormones and illicit substances. Infectious agents, such as staphylococcus or B. cereus are self limiting, lasting up to 1-2 days.
     There is a three step approach to evaluating N/V. First, the consequences of the N/V should be addressed, such as dehydration or electrolyte issues. Then, the underlying cause should be diagnosed and treated. Lastly, empiric therapy should be started if the cause cannot be determined or if treatment is an ongoing process. A proper history and exam will reveal most the clues. Labs and imagining should be led by the initial evaluation. Emergent situations (such as chest pain, CNS problems, fever, hypotension, severe dehydration, and severe abdominal pain) should be properly evaluated. Pregnancy is a common cause of N/V. It can lead to morning symptoms or hyperemesis gravidarum.
     There is a really nice list of the possible diagnosis in this article based on history , so let me try and break it down a bit. If the onset is abrupt, think food poisoning, drugs medications, pancreatitis, gastroenteritis, or cholecystitis. It may also be infectious or iatrogenic. If the onset is subtle, consider GERD, pregnancy, gastroparesis, medications or metabolic disorders. If the timing of the N/V occurs right after eating, it may be psychiatric. If its 1-4 hours after eating, consider a gastric outlet obstruction. Symptoms before breakfast could signal pregnancy, uremia, alcohol or increased ICP. If there is associated abdominal pain, the location can also play a part in the diagnosis. 
     As far as the physical exam is concerned, the patient initially should be evaluated for dehydration, by looking at skin turgor, mucus membranes, orthostatic changes or hypotension/ tachycardia.  Fingertips, parotid gland enlargement, laguno and teeth enamel can be evaluated for signs of forced vomiting.  Loss of tooth enamel can also be from GERD. Distention can be from obstruction, but bloating may be from gastroparesis. Increased bowel sounds could be a sign of obstruction. Decreased sounds are a sign of ileus. Scars, hernias or evidence of previous surgeries can also be an important discovery.  An cranial nerve exam (including the eye) could point towards a brainstem lesion or increased cranial pressure.
     Lab tests can reveal inflammation, pregnancy, thyroid issues, pancreatitis or electrolyte abnormalities.  X rays (supine and upright) can show an obstruction. An EGD can detect mucosal lesions in the stomach and small intestine. A small bowel follow-through can see as far as the terminal ileum. Enteroclysis can see some of the smaller lesions that may be missed by the former procedures. Gastric motility studies can help diagnosis gastroparesis, gastric arrhythmias, or other motor disorders. Since these tests are somewhat controversial, a trial of a prokinetics and antiemetics may be a better place to start. 
     Fluid and electrolyte replacement is a cornerstone of treatment, as well as a proper diet. While you are working on the diagnosis and trying to figure out the underlying cause, you can start the patient on a phenothiazine or metoclopramide (prokinetic agent). Ondansetron is more effective than the first two, but it is cost prohibitive. There are many types of antiemetics available, but some have side effects to watch for.  Scopolamine is an anticholinergic, which may cause drowsiness, dry mouth and vision problems. Phenothiazines and metoclopramide have extrapyramidal side effects, such as dyskinesia and dystonia.