Nausea & Vomiting
Taylor Riggs
Etiology VOMMIIT mnemonic
- Vestibular: Labyrinthitis, vestibular neuritis, Meniere’s disease, cerebellar stroke
- Obstruction: adhesions, hernia, volvulus, constipation, gastric outlet obstruction
- Motility: gastroparesis, GERD, autonomic dysfunction
- Medications: antibiotics, SSRI, opioids, cannabinoid hyperemesis
- Infection: gastroenteritis, hepatitis, pyelonephritis, cholecystitis
- Inflammation: PUD, pancreatitis
- Toxins: uremia, ketoacidosis, hypercalcemia, chemotherapy
Evaluation
- All patients: CBC (leukocytosis, Hgb), BMP (AG, Ca, lytes, AKI), LFTs, lipase, lactate, UA
- If risk factors: consider TSH, AM cortisol, troponin, β hCG, UDS
- EKG to eval for ischemia and baseline QTc
- Imaging
- If concern for obstruction (abd distention, decreased BMs) à KUB, consider CT A/P
- If concern for biliary pathology (RUQ pain, abnl LFTs) à RUQ U/S
- If vestibular/concern for CNS pathology à CTH vs MRI brain
Management
Address underlying cause and stop medications as appropriate
- Many antiemetics prolong QTc, however in patients without underlying cardiac conduction abnormality, electrolyte abnormality, or organ failure the risk of QTc prolongation leading to significant arrhythmia is low.
- Obtain screening EKG in patients with underlying heart disease, electrolyte abnormalities, organ failure or on other QTc prolonging meds (antiarrhythmics, antipsychotics, antibiotics)
- 4-8 mg of IV Zofran is estimated to prolong QTc by ~6ms
- Try to pick a medication that will address the underlying etiology of nausea
- If patient does not respond to a medication in a certain class, try a medication from a different class (see below)
Anti-Emetics
Med (by class) | Typical Dose | Side Effects | Prolongs QT? |
|---|---|---|---|
| Serotonin antagonists | |||
| Ondansetron (Zofran) | 4-8mg PO/IV q6h | Constipation, headache, arrhythmia, serotonin syndrome | Yes |
| Granisetron (Kytril)1 | 1 mg PO BID, 2mg pre-chemo, OR 10mcg/kg IV prechemo | Constipation, headache, arrhythmia, serotonin syndrome | Yes |
| Dopamine Antagonists | |||
| Prochlorperazine (Compazine) | 5-10 mg PO/IV q6h, 25 mg PR q6h | EPS, less sedation than Hblockers (e.g. Phenergan) | Yes |
| Haloperidol (Haldol) | 0.5-1 mg PO/IV q6h | EPS, arrhythmia | Yes |
| Zyprexa (Olanzapine) | 5 -10mg PO qdaily | EPS, constipation, anticholinergic | Mild ^ |
| Dopamine and Serotonin Antagonists | |||
| Metoclopramide (Reglan) | 10 mg PO/IV q6h | EPS/dystonia, arrhythmias, drowsiness/dizziness, diarrhea | Yes |
| GABA-A Agonist | |||
| Lorazepam (Ativan) | 0.5-1mg PO/IV q6h PRN | Sedation, delirium, amnesia, respiratory depression | No |
| H1 Antagonists | |||
| Promethazine (Phenergan) | 12.5 - 25mg PO /PR/IV q6h (avoid IV use if possible) | Sedation, EPS (D2 antagonist also), arrhythmias, blurry vision | Yes |
| Diphenhydramine (Benadryl) | 25-50mg PO/IV q6h | Sedation, delirium, urinary retention, ileus | Yes |
| Meclizine (Antivert) | 12.5-25mg PO q6h | Sedation, dizziness, falls, blurry vision | Yes |
| Anticholinergics | |||
| Scopolamine | 1 mg patch q3day | Dry mouth, blurry vision, drowsiness | No |
| Glucocorticoids | |||
| Dexamethasone | 4-8mg PO/IV prior to chemo or XRT, typically use with other agents | Hyperglycemia, fluid retention, delirium | No |
| NK1 Antagonists | |||
| Aprepitant | Given prior to/with chemo | Fatigue, neutropenia | No |
| CBD Agonists | |||
| Dronabinol | 2.5-5mg BID | Dizziness, increased appetite, Tachycardia, hypotension | No |