Parameters for Holding Antihypertensive Medications
Hold antihypertensive medications when systolic blood pressure is <90 mm Hg or mean arterial pressure is <60-65 mm Hg, as maintaining pressures below these thresholds for approximately 15 minutes is associated with myocardial injury, acute kidney injury, and mortality. 1
Critical Blood Pressure Thresholds for Holding Medications
Absolute Parameters for Withholding Treatment
- Systolic BP <90 mm Hg is the primary threshold below which antihypertensive medications should be held to prevent end-organ damage 1
- Mean arterial pressure (MAP) <60-65 mm Hg represents the harm threshold where tissue perfusion becomes compromised 1
- Duration matters: These low pressures maintained for approximately 15 minutes trigger the cascade of complications 1
Perioperative Context (Highest Quality Evidence)
The 2024 AHA/ACC guidelines provide the most specific parameters for the perioperative period:
- Continue most antihypertensives throughout the perioperative period in patients with controlled hypertension 1
- Hold ACE inhibitors and ARBs on the day of surgery due to increased risk of intraoperative hypotension 1
- Never abruptly discontinue beta-blockers or clonidine due to rebound hypertension risk 1
- Defer elective surgery if recent SBP ≥180 mm Hg or DBP ≥110 mm Hg in patients with cardiovascular risk factors 1
Drug-Specific Considerations
Medications That Should NOT Be Held Abruptly
- Beta-blockers: Abrupt discontinuation causes rebound hypertension and tachycardia 1
- Clonidine: Sudden withdrawal triggers severe rebound hypertension 1
- These should be continued even when other antihypertensives are held
Medications With Higher Risk of Hypotension
- ACE inhibitors and ARBs: Associated with increased intraoperative hypotension when continued 1
- Consider holding these specifically in perioperative settings while maintaining other agents
Target Blood Pressure Ranges by Population
General Adult Population
- Hold medications if SBP approaches <90 mm Hg 1
- Target maintenance of SBP ≥90 mm Hg in younger adults 1
Older Adults (≥65 years)
- Higher BP targets are preferred: SBP range of 130-139 mm Hg is appropriate 1
- More conservative holding threshold: Consider holding medications if SBP <100-110 mm Hg in elderly patients with chronic hypertension 1
Patients with Chronic Kidney Disease
- Target SBP 130-139 mm Hg for most CKD patients 1
- **Hold if SBP <120 mm Hg** in those with eGFR >30 mL/min/1.73 m² 1
- Individualize based on electrolytes and renal function changes 1
Pregnant Women (Emergency Parameters)
- SBP ≥170 mm Hg or DBP ≥110 mm Hg requires immediate hospitalization 1
- Do not lower DBP below 80 mm Hg in pregnancy 1
- Hold medications if approaching these lower thresholds
Common Pitfalls to Avoid
White Coat Effect
- Single elevated reading on surgery day may represent situational hypertension, not true uncontrolled disease 1
- Refer to baseline ambulatory BP rather than reacting to isolated measurements 1
- Avoid holding chronic medications based solely on one low reading
Symptomatic Hypotension
- Hold medications immediately if patient develops symptoms (dizziness, syncope, confusion) regardless of absolute BP number
- Symptoms indicate inadequate cerebral perfusion even if BP appears "acceptable"
Medication Adherence Assessment
- Exclude pseudo-resistance before intensifying therapy 2
- Verify actual medication adherence before assuming treatment failure
Algorithm for Decision-Making
Check current BP and compare to baseline
- If SBP <90 mm Hg or MAP <60-65 mm Hg → Hold all antihypertensives except beta-blockers/clonidine 1
Assess duration of hypotension
- If sustained >15 minutes → Urgent intervention needed, hold medications 1
Consider patient-specific factors
Evaluate clinical context
- Perioperative: Hold ACE-I/ARBs, continue beta-blockers 1
- Acute illness/dehydration: Hold diuretics and RAS blockers
- Symptomatic: Hold immediately regardless of numbers