What is the assessment and management plan for a patient with cyclic vomiting in the observation unit?

Assessment and Management of Cyclic Vomiting Syndrome in the Observation Unit

Immediate Assessment

Place the patient in a quiet, dark room immediately to minimize sensory stimulation, as patients in the emetic phase are often agitated and have difficulty communicating effectively. 1, 2

Critical Diagnostic Distinctions

• Screen for cannabis use first: Use >4 times weekly for >1 year suggests cannabinoid hyperemesis syndrome (CHS) rather than CVS, requiring 6 months of cessation to differentiate 3, 4
• Note that hot water bathing occurs in 48% of CVS patients who don't use cannabis, so this behavior alone does not distinguish CHS from CVS 2
• Check for bilious or bloody vomiting, which requires urgent surgical evaluation 4

Recognize the CVS Phase

• Prodromal phase (median 1 hour): Look for impending sense of doom, panic, anxiety, diaphoresis, flushing, mental fog, restlessness, headache, or bowel urgency 1, 3
• Emetic phase: Uncontrollable retching and vomiting lasting hours to days, with patients appearing agitated and unable to communicate 1, 2
• Most episodes occur in early morning hours 1
• Abdominal pain is present in most patients and should not preclude diagnosis 1

Initial Laboratory Workup

• Complete metabolic panel with electrolytes (check and correct abnormalities immediately) 2, 4
• Liver function tests 4
• Pregnancy test 4
• Thyroid function tests 4
• Monitor for hypertensive episodes, as CVS can cause severe hypertension leading to complications 5

Acute Management in Observation Unit

First-Line Interventions

Administer aggressive IV fluid replacement with dextrose-containing fluids (10% dextrose) for rehydration and metabolic support. 3, 2, 6

Give ondansetron 8 mg IV every 4-6 hours as first-line antiemetic. 3, 2

Use IV ketorolac as first-line non-narcotic analgesia for severe abdominal pain (avoid opioids as they worsen nausea and carry addiction risk). 1, 3

Sedation Strategy

• Administer IV benzodiazepines for sedation in the quiet, dark room 3, 2
• Sedation can truncate severe episodes in some cases 3, 6
• Additional sedating agents include diphenhydramine 3

Refractory Cases

For patients not responding to initial therapy, use droperidol or haloperidol as dopamine antagonists. 3, 2

• Multiple concurrent agents with different mechanisms of action may be necessary, administered around-the-clock rather than PRN 2
• Consider promethazine 12.5-25 mg IV/rectal every 4-6 hours or prochlorperazine 5-10 mg every 6-8 hours 3

Common Pitfalls to Avoid

• Do not overlook retching and nausea: These symptoms are equally disabling as vomiting itself and require aggressive treatment 1, 2, 4
• Do not misinterpret self-soothing behaviors: Excessive water drinking or self-induced vomiting are specific to CVS and provide temporary relief, not malingering 2
• Do not underestimate severity: Approximately one-third of adults with CVS become disabled 2

Disposition Planning and Patient Education

Abortive Therapy Education

Educate the patient to take abortive medications immediately at the onset of prodromal symptoms, as missing this window dramatically reduces effectiveness. 3, 2, 4

• Standard abortive regimen: Sumatriptan 20 mg intranasal spray PLUS ondansetron 8 mg sublingual every 4-6 hours 3, 4
• Sumatriptan can be repeated once after 2 hours (maximum 2 doses per 24 hours) 3
• Administer sumatriptan in head-forward position to optimize medication contact with anterior nasal receptors 3

Prophylactic Therapy Initiation

For moderate-severe CVS (≥4 episodes/year lasting >2 days requiring ED visits), initiate amitriptyline 25 mg at bedtime with plan to titrate to 75-150 mg nightly. 3, 2, 4

• Response rate is 67-75% 3, 2
• Obtain baseline ECG due to QTc prolongation risk 3
• Goal dose is 1-1.5 mg/kg at bedtime 3

Psychiatric Screening and Comorbidity Management

Screen all patients for anxiety, depression, and panic disorder, as these are present in 50-60% of CVS patients, and treating underlying anxiety decreases episode frequency. 3, 2, 4

Lifestyle Modifications

• Maintain regular sleep schedule and avoid sleep deprivation 3, 4
• Avoid prolonged fasting 3, 4
• Implement stress management techniques 3, 4
• Identify and avoid individual triggers (stress, infections, menstrual cycle, travel, motion sickness) 1, 3

Follow-Up Arrangements

• Arrange outpatient gastroenterology follow-up for ongoing prophylactic management 3
• Consider psychology/psychiatry referral for cognitive-behavioral therapy to manage psychological triggers 2, 7
• Provide written action plan with abortive medication instructions for home use 3, 2