What is the appropriate evaluation and management of vomiting in a reproductive‑age woman following a dilation and curettage?

Workup and Management of Vomiting After Dilation and Curettage

Immediately assess hydration status and administer intravenous fluids to maintain adequate perfusion, then treat with ondansetron 4-8 mg IV as first-line antiemetic therapy. 1, 2, 3

Initial Assessment and Stabilization

Hydration Status Evaluation

• Check vital signs for orthostatic hypotension (blood pressure drop >20 mmHg systolic or >10 mmHg diastolic when standing), tachycardia, and signs of dehydration including dry mucous membranes, decreased skin turgor, and reduced urine output. 1
• Initiate IV crystalloid resuscitation immediately if dehydration is present, as adequate hydration reduces nausea independent of antiemetic drugs and is critical after procedures with potential blood loss. 1, 3
• Target fluid administration of ≥1.5 L/day to maintain adequate hydration, with increased requirements if vomiting persists. 1

Timing and Severity Assessment

• Determine whether vomiting began intraoperatively (suggesting anesthesia-related causes) or postoperatively (suggesting surgical complications or medication effects). 1
• Assess frequency and volume of vomiting episodes, as persistent vomiting >2-3 weeks requires thiamin supplementation to prevent neurological complications. 1

First-Line Antiemetic Therapy

Ondansetron Administration

• Administer ondansetron 4-8 mg IV over 2-5 minutes as initial treatment for established postoperative nausea and vomiting. 2, 3, 4
• Use 8 mg dosing for moderate-to-severe symptoms, with repeat dosing every 12 hours as needed, maximum 16 mg/day. 2, 4
• Monitor QT interval in patients with cardiac risk factors, electrolyte abnormalities, or concurrent QT-prolonging medications. 2, 3, 4

Supportive Measures

• Prescribe stool softeners prophylactically when ondansetron is used, as constipation worsens with cumulative exposure and dehydration. 2, 3
• Encourage oral fluid intake once tolerated, avoiding carbonated and sugar-sweetened beverages. 1

Rescue Therapy for Persistent Vomiting

Second-Line: Dopamine Antagonists

• If nausea persists 30-60 minutes after ondansetron, switch to metoclopramide 10 mg IV (administered slowly over 1-2 minutes) rather than repeating ondansetron, as using the same drug class for rescue reduces effectiveness. 2, 3, 4
• Alternative dopamine antagonists include prochlorperazine 5-10 mg IV/PO every 6 hours or haloperidol 0.5-2 mg IV/PO every 4-6 hours when metoclopramide is contraindicated. 2, 3, 4
• Monitor for extrapyramidal symptoms with dopamine antagonists, especially at higher doses; low-dose haloperidol (0.5-2 mg) has minimal risk. 2

Third-Line: Add Corticosteroid

• Add dexamethasone 4 mg IV for refractory nausea that persists after ondansetron plus a dopamine antagonist. 2, 3, 4
• This dose provides effective antiemetic benefit without additional advantage from higher doses and avoids excess hyperglycemia risk. 3

Multimodal Approach for Severe Cases

• For intractable vomiting, continue the dopamine antagonist, add dexamethasone 4 mg IV (if not already given), and consider lorazepam 0.5-2 mg IV/PO every 6 hours for anticipatory or anxiety-related nausea. 2, 3
• Consider scopolamine transdermal patch (1.5-3 mg over 72 hours) if oral secretions are problematic. 2, 3

Evaluation for Surgical Complications

Red Flags Requiring Urgent Investigation

• Refractory vomiting despite compliance with nutritional recommendations and multimodal antiemetic therapy may indicate surgical complications including retained products of conception, uterine perforation, bowel injury, or infection. 1
• Assess for fever, severe abdominal pain, peritoneal signs, or abnormal vaginal bleeding/discharge that would suggest endometritis, perforation, or other complications. 1
• Bilious vomiting or abdominal distension suggests possible bowel obstruction from unrecognized bowel injury during the procedure. 1

Laboratory and Imaging Considerations

• Check complete blood count if significant bleeding is suspected, and metabolic panel to assess electrolyte abnormalities from persistent vomiting. 1
• Consider pelvic ultrasound if retained products of conception are suspected or if clinical examination is concerning for uterine perforation. 1
• Obtain surgical consultation immediately if peritoneal signs, severe pain, or hemodynamic instability are present. 1

Nutritional Management

Early Oral Intake

• Resume regular diet within 2 hours after D&C once patient is alert and hemodynamically stable, as early feeding improves recovery without increasing complications. 1
• If vomiting prevents oral intake, maintain IV hydration and reassess tolerance every 2-4 hours. 1

Eating Behavior Modifications

• Instruct patient to eat slowly, chew thoroughly (≥15 chews per bite), and consume small quantities at each meal to prevent regurgitation. 1
• Avoid dry foods and encourage consumption of easily digestible options if nausea persists. 1

Prevention of Complications

Thiamin Supplementation

• Initiate thiamin supplementation if vomiting persists for >2-3 weeks to prevent Wernicke encephalopathy and other neurological complications. 1

Opioid Minimization

• Limit postoperative opioid use as opioids are a strong predictor of postoperative nausea; substitute oral acetaminophen or NSAIDs for pain control. 3
• Use multimodal analgesia including regular NSAIDs and paracetamol to reduce opioid requirements. 1

Common Pitfalls to Avoid

• Do not repeat ondansetron dosing beyond 16 mg/day or use scheduled three-times-daily dosing, as this increases QT prolongation risk without additional benefit. 2, 4
• Do not use ondansetron as monotherapy for rescue if the patient received ondansetron prophylactically during surgery; switch to a different antiemetic class. 2, 3, 4
• Do not delay evaluation for surgical complications if vomiting is severe, persistent, or accompanied by fever, severe pain, or peritoneal signs. 1
• Do not assume all postoperative vomiting is benign; maintain high index of suspicion for uterine perforation or bowel injury, especially if vomiting is bilious or associated with abdominal distension. 1