How to manage hypertension in an asymptomatic elderly woman on metoprolol (beta blocker) 25mg twice daily (bd) with a blood pressure of 188 mmHg the night before a scheduled colonoscopy?

Management of Hypertension in an Elderly Woman Before Colonoscopy

For an asymptomatic elderly woman with a blood pressure of 188 mmHg the night before a scheduled colonoscopy, increase her metoprolol dose to 50mg immediately and consider adding a calcium channel blocker if available. 1

Assessment of the Situation

This is a case of severe hypertension (BP 188 mmHg) in an elderly woman who:

• Is currently on metoprolol 25mg twice daily
• Is asymptomatic (no headache, visual changes, chest pain, etc.)
• Has a scheduled colonoscopy the next morning
• Needs urgent but careful blood pressure management

Management Algorithm

Step 1: Immediate Intervention

• Increase metoprolol dose from 25mg to 50mg immediately 1, 2
• Recheck blood pressure in 1 hour
• Ensure patient remains in a calm, quiet environment

Step 2: Based on Response

• If BP decreases by at least 20 mmHg: Continue monitoring
• If BP remains >170 mmHg: Consider adding a calcium channel blocker (if available) 1
• If BP rises further or patient becomes symptomatic: Consider postponing the colonoscopy

Step 3: Overnight Monitoring

• Check BP every 2-3 hours overnight
• Target: Gradual reduction toward 160/90 mmHg 1
• Avoid aggressive BP lowering which could cause hypotension during colonoscopy prep

Rationale for This Approach

1. Dose Adjustment: Metoprolol dose can be safely increased in elderly patients. Research shows that doses up to 100mg daily are well-tolerated in elderly hypertensive patients 2, 3.

2. Timing Considerations: The patient is already on metoprolol, making dose adjustment safer than introducing a new medication class the night before a procedure 1.

3. Procedural Safety: Extremely high blood pressure increases risks during colonoscopy, but overly aggressive treatment could lead to hypotension during bowel prep (which can cause volume depletion).

Important Considerations

• Avoid Diuretics: Do not add a diuretic given the upcoming colonoscopy prep which will cause fluid loss 1

• Beta-Blocker Caution: While increasing the dose is reasonable, monitor for bradycardia, especially in an elderly patient 4

• Colonoscopy Timing: If BP cannot be controlled to <170 mmHg, discuss with the gastroenterologist about potential postponement

• Post-Procedure Plan: After colonoscopy, comprehensive reassessment of her antihypertensive regimen is needed, as 25mg BD of metoprolol is clearly insufficient 1, 3

Common Pitfalls to Avoid

• Overly Aggressive Treatment: Rapid BP reduction can cause organ hypoperfusion in elderly patients

• Ignoring the Asymptomatic Status: While 188 mmHg is concerning, absence of symptoms allows for more measured intervention

• Medication Interactions: Be cautious about adding medications that might interact with bowel prep or sedatives used during colonoscopy

• Neglecting Long-Term Management: This event indicates inadequate baseline control requiring medication adjustment after the procedure

The goal is to balance the immediate need to lower blood pressure with the practical considerations of the upcoming procedure, while ensuring patient safety throughout.