Management of Postoperative Hypertension in a Patient on Losartan 50mg Daily

Losartan 50mg daily should be resumed as soon as clinically feasible after surgery to prevent complications from postoperative hypertension. 1

Pathophysiology and Risk Assessment

Postoperative hypertension can occur due to various stimuli including pain, inflammation, anxiety, hypoxia, volume overload, urinary retention, or withdrawal of chronic antihypertensive medications 1
Hypertension in the perioperative period increases the risk of cardiovascular disease, cerebrovascular events, and bleeding 1
Patients with hypertension (controlled or uncontrolled) demonstrate a more labile hemodynamic profile than their non-hypertensive counterparts 1
Untreated postoperative hypertension can increase the risk for myocardial ischemia/infarction, acute decompensated heart failure, cerebral ischemia, and dysrhythmias 1

Address pain, anxiety, hypothermia, hypoxemia, and urinary retention before implementing antihypertensive therapy 2
Check for volume overload which may contribute to postoperative hypertension 1

Resume losartan 50mg daily as soon as the patient can take oral medications 1
Delaying resumption of preoperative ACEi/ARBs has been associated with increased 30-day mortality risk 1
The usual dose of losartan for hypertension is 50mg once daily, which can be increased to a maximum of 100mg once daily as needed to control blood pressure 3

If blood pressure remains elevated despite resuming losartan 50mg daily, consider:
- Increasing losartan to 100mg daily if needed for better blood pressure control 3
- Higher doses of losartan (100-150mg) have shown better cardiovascular outcomes in clinical trials, similar to findings with ACE inhibitors 4
- The HEAAL trial showed a 10% relative risk reduction in death or heart failure hospitalization with losartan 150mg daily compared to 50mg daily 1

If blood pressure remains uncontrolled on maximum losartan dose:
- Add hydrochlorothiazide 12.5mg daily, which can provide additional blood pressure reduction when combined with losartan 3, 5
- Consider adding a calcium channel blocker if further blood pressure control is needed 6

Avoid intensification of antihypertensive therapy at hospital discharge as this may increase the 30-day risk of readmission and serious complications, particularly in older adults 1
Losartan has a favorable drug interaction profile and can be safely combined with other medications commonly used in the postoperative period 7
Losartan is well-tolerated with minimal side effects; dizziness is the most common drug-related adverse effect (2.4% versus 1.3% with placebo) 5
For patients with mild-to-moderate hepatic impairment, a lower starting dose of 25mg may be appropriate 3

Monitor blood pressure regularly in the postoperative period, particularly during the first 24-48 hours after resuming losartan 1
Target blood pressure should be individualized based on the patient's baseline values, but generally maintaining systolic blood pressure <180 mmHg and diastolic blood pressure <110 mmHg is reasonable in the immediate postoperative period 1
Pay special attention to renal function and electrolytes, particularly potassium levels, when resuming losartan therapy 7

Avoid abrupt withdrawal of losartan as this may lead to rebound hypertension 1
Be cautious with volume status assessment, as hypovolemia can exacerbate hypotension when losartan is resumed 1
If the patient cannot take oral medications immediately after surgery, consider appropriate intravenous antihypertensive agents until oral intake is possible 1
Losartan's onset of action is 1-2 hours after oral administration, with peak effect at 6 hours, so anticipate a delay in blood pressure control after resuming the medication 7