From the Guidelines
In patients with hypertensive emergency and acute kidney injury (AKI), fluid administration is recommended to optimize renal perfusion 1.
Key Considerations
- The choice of fluid is crucial, with isotonic crystalloids (such as 0.9% saline) preferred over colloids (albumin or starches) as initial management for expansion of intravascular volume in patients at risk for AKI or with AKI 1.
- A bolus of 500-1000 mL of 0.9% saline or lactated Ringer's solution may be given over 30 minutes to 1 hour, with subsequent infusion rates titrated to maintain a urine output of at least 0.5 mL/kg/hour.
- It is essential to maintain optimal kidney function and avoid overzealous fluid resuscitation, which may increase the risk of complications such as acute lung injury and the need for ventilation 1.
Medications to Enhance Renal Blood Flow
- Medications such as fenoldopam (at a dose of 0.1-0.3 mcg/kg/minute) or dopamine (at a dose of 1-2 mcg/kg/minute) may be considered to enhance renal blood flow and function, although their use should be guided by the individual patient's clinical context and response to treatment 1.
- The treatment of hypertensive emergencies should be driven by the type of hypertensive organ damage, with controlled BP reduction being the therapeutic goal to prevent or limit further hypertensive damage 1.
From the Research
Fluid Administration in Hypertensive Emergency and Acute Kidney Injury (AKI)
- In patients with hypertensive emergency and AKI, the management is directed at the specific situation, with the rate and extent of blood pressure lowering tailored to the type and extent of organ damage 2.
- Fluid administration may increase renal perfusion, but its effects are quite unpredictable and can be dissociated from its impact on cardiac output and arterial pressure 3.
- The optimal mean arterial pressure (MAP) target level remains undefined, and it is reasonable to individualize MAP target, paying attention to central venous and intraabdominal pressures, as well as to the response to an increase in MAP 3.
- In selected patients with preserved tissue perfusion presenting signs of fluid intolerance, safe fluid withdrawal may be achieved, and stopping rules should be set 3.
- There is no direct evidence to recommend fluid administration in patients with hypertensive emergency and AKI, and the management should be tailored to the individual patient's needs and response to treatment 3, 4, 5, 6.
Key Considerations
- The treatment of acute severe hypertension varies according to the hospital unit, medication, and blood pressure targets or thresholds 4.
- Patients with acute aortic dissection require immediate blood pressure lowering with intravenous esmolol, and vasodilators such as nitroglycerin or nitroprusside may be administered if blood pressure persists 4.
- Intravenous administration of clevidipine, nicardipine, or phentolamine may be required to achieve the desired reduction in blood pressure 4.
- The use of intravenous medications in hospitalized hypertensive patients without organ dysfunction is common, and outcomes are similar to oral administration, except for length of stay 5.