Can Acute Kidney Injury (AKI) cause hypotension?

Does AKI Cause Low BP?

No, AKI does not typically cause hypotension—in fact, hypertension is far more common in AKI, occurring in approximately 70% of patients. 1 The relationship between AKI and blood pressure is complex and depends heavily on the underlying cause and clinical context.

The Typical Blood Pressure Pattern in AKI

• Hypertension is the predominant finding in AKI, with prevalence varying by etiology: post-renal AKI (85%), renal/intrinsic AKI (75%), and pre-renal AKI (30%). 1
• Severe prolonged hypertension can actually cause AKI through intrarenal vasoconstriction, altered renal hemodynamics, and acute tubular necrosis. 2
• Patients with AKI requiring dialysis tend to have higher blood pressure and require more antihypertensive medications. 1

When Hypotension Occurs in the Context of AKI

Hypotension as a Cause, Not a Consequence

• Hypotension typically precedes and causes AKI rather than resulting from it. Relative hypotension (decreased systolic blood pressure compared to baseline) is significantly more common in patients who develop nosocomial AKI. 3
• Every 1 mmHg decrease in systolic blood pressure relative to pre-morbid values increases the odds of developing AKI by 8.4%. 3
• Early-phase cumulative hypotension duration is strongly associated with progression to severe-stage AKI, particularly in non-septic patients. 4

Critical Thresholds and Timing

• The first 6 hours after AKI diagnosis are crucial. Time spent below MAP of 65 mmHg during this period increases risk of progression to stage-3 AKI (adjusted OR 3.73). 4
• Even higher MAP thresholds matter: time spent below MAP of 85 mmHg in the first 6 hours after cardiac arrest increases severe AKI risk by 8% for every 10% increase in time below threshold. 5
• Maintaining MAP >65 mmHg is essential, with vasopressors recommended in conjunction with fluids for patients with vasomotor shock. 6

Clinical Management Implications

Hemodynamic Support Strategy

• Use vasopressors with fluids rather than aggressive fluid resuscitation alone in patients with hypotension and AKI, particularly in the setting of heart failure or volume overload. 6, 7
• Isotonic crystalloids are preferred over colloids for volume expansion when fluid administration is indicated. 6
• Avoid synthetic colloids (hydroxyethyl starch) as they increase AKI incidence and mortality. 6, 7

Common Pitfall to Avoid

• Do not misinterpret "pre-renal" AKI as always meaning "hypovolemic." This outdated framework encourages indiscriminate fluid administration, which can worsen outcomes, particularly in patients with volume overload or heart failure. 6
• Fluid administration should be guided by repeated hemodynamic assessment and dynamic tests of fluid responsiveness, not reflexive volume loading. 6

Special Consideration: Intradialytic Hypotension

• Hypotension during dialysis can cause further ischemic kidney injury and reduce the probability of renal recovery in patients with AKI requiring renal replacement therapy. 8
• This represents a scenario where hypotension occurs as a complication of AKI treatment rather than from AKI itself. 8