Nausea & Vomiting – Michael J. Neuss
General Approach:
- VOMIT mnemonic (see below)
- Several antiemetics can prolong QT interval (see below). Caution is advised when QTc is prolonged (>450 in men and >470 in women), particularly if hypokalemia, hypomagnesemia, or if taking multiple medications with QT prolonging effects.
- Consider drug use and withdrawal, medication effects, cardiac ischemia, pregnancy, abdominal pathology, adrenal insufficiency, CNS lesion, anxiety, severe pain
- Labs: BMP, hepatic functional panel, lactate, amylase/lipase, TSH, cortisol (AM vs cort stim), troponin, β hCG, U/A, UDS
- EKG (know QT, eval for ischemia), KUB/upright, Small bowel follow-through (SBFT)
- CT A/P, CNS imaging (CT vs MRI; eval for mets in oncology pts)
- EGD has limited utility unless mechanical gastric outlet obstruction is suspected
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VOMIT |
Etiologies |
Management |
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Vestibular & Vertigo |
Labyrinthitis, Vestibular neuritis, Meniere’s disease Cerebellar stroke |
- Scopolamine, diphenhydramine - Check for nystagmus, truncal ataxia, focal deficits; consider CNS imaging if high risk - VUMC: consider referral to Pi β Phi for vertigo |
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Obstruction |
Adhesions, hernia, volvulus, constipation Gastric outlet obstruction (pyloric stenosis from malignancy or PUD) |
- Bowel Obstruction: KUB (about 80% sensitive) vs. CT A/P, Surgical consultation (general surgery at VA and EGS at VUMC) - SBFT – both diagnostic and therapeutic - Bowel rest, NGT (if tolerated/indicated), bowel regimen - Gastric outlet obstruction: Inflammation may respond to acid suppression and NGT to suction - Endoscopic dilation, surgery or stenting |
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Motility |
GERD, Gastroparesis, autonomic dysfunction (e.g. in diabetics) |
- If GERD, trial of PPI and de-escalate to H2 blocker once able - Metoclopramide (caution due to side effects, erythromycin second line) - Consider gastric emptying study (limited sensitivity & specificity ONLY outpt off narcotics) - Consider autonomics evaluation |
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Meds |
Antibiotics, SSRI, Opioids cannabinoid hyperemesis |
- UDS, CSMD search - Careful med review - Ondansetron - Cannabinoid hyperemesis syndrome: hot showers cyclically. Stop cannabis |
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Inflammation or Infection |
Gastroenteritis, PUD, hepatitis, pyelonephritis, nephrolithiasis, cholecystitis, pancreatitis |
- Ondansetron, other agents acceptable - Treat underlying problem |
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Toxins |
Uremia, ketoacidosis, hypercalcemia, chemotherapy |
- Ondansetron, others acceptable - Treat underlying problem - Pre-treatment for chemo ( usually part of chemo order sets) |
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Anti-Emetics |
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Med (by class) |
Dose |
Side effects? |
QT? |
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Serotonin antagonists |
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Ondansetron (Zofran) |
4-8mg PO/IV q6h |
Constipation, headache |
++ |
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Granisetron (Kytril)1
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2 mg PO x1, 1 mg PO BID pre-chemo, daily patch, OR 10mcg/kg pre-chemo |
‘’ |
++ |
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Dopamine antagonists |
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Prochlorperazine (Compazine) |
5-10 mg PO q6h, 2.5 – 10 mg IV q6h, 25 mg PR q6h |
EPS, less sedation than anti-H |
+ |
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Haloperidol (Haldol) |
0.5-1 mg PO/IV q6h |
‘’ |
++ |
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Zyprexa (Olanzapine)2 |
2.5-10mg PO q6H |
‘’ |
+ |
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Metoclopramide (Reglan) |
10 mg PO/IV q6h |
EPS, dystonia, tardive dyskinesia |
+ |
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GABAergic |
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Lorazepam (Ativan) |
0.5-2mg PO; 0.25 – 1 mg IV q6h |
Sedation, delirium |
- |
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Antihistamines |
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Promethazine (Phenergan) |
12.5 - 25mg PO/IV q6h OR 25 mg PR q6h |
Sedation, EPS (DA antagonist as well) |
+ |
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Diphenhydramine (Benadryl) |
25-50mg PO/IV q6h |
Sedation, delirium, urinary retention, ileus |
- |
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Meclizine (Antivert) |
25 – 50 mg PO qday |
‘’ |
- |
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Anticholinergics |
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Scopolamine (Hyoscine) |
1.5 mg patch q3day |
‘’ |
- |
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Other |
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Dexamethasone (Decadron)3 |
20 mg PO or IV for CINV; can give with Ondansetron 8-18 mg or Granisetron 10mcg/kg IV or 2 mg PO if high severity CINV |
Hyperglycemia, fluid retention |
- |