Permissive azotemia during acute kidney injury enables more rapid renal recovery and less renal fibrosis: a hypothesis and clinical development plan.

Preclinical models of acute kidney injury (AKI) consistently demonstrate that a uremic milieu enhances renal recovery and decreases kidney fibrosis. Similarly, significant decreases in monocyte/macrophage infiltration, complement levels, and other markers of inflammation in the injured kidney are observed across multiple studies and species. In essence, decreased renal clearance has the surprising and counterintuitive effect of being an effective treatment for AKI. In this Perspective, the author suggests a hypothesis describing why the uremic milieu is kidney protective and proposes a clinical trial of 'permissive azotemia' to improve renal recovery and long-term renal outcomes in critically ill patients with severe AKI.

Outcomes in Patients with Vasodilatory Shock and Renal Replacement Therapy Treated with Intravenous Angiotensin II.

OBJECTIVE: Acute kidney injury requiring renal replacement therapy in severe vasodilatory shock is associated with an unfavorable prognosis. Angiotensin II treatment may help these patients by potentially restoring renal function without decreasing intrarenal oxygenation. We analyzed the impact of angiotensin II on the outcomes of acute kidney injury requiring renal replacement therapy. DESIGN: Post hoc analysis of the Angiotensin II for the Treatment of High-Output Shock 3 trial. SETTING: ICUs. PATIENTS: Patients with acute kidney injury treated with renal replacement therapy at initiation of angiotensin II or placebo (n = 45 and n = 60, respectively). INTERVENTIONS: IV angiotensin II or placebo. MEASUREMENTS AND MAIN RESULTS: Primary end point: survival through day 28; secondary outcomes included renal recovery through day 7 and increase in mean arterial pressure from baseline of ≥ 10 mm Hg or increase to ≥ 75 mm Hg at hour 3. Survival rates through day 28 were 53% (95% CI, 38%-67%) and 30% (95% CI, 19%-41%) in patients treated with angiotensin II and placebo (p = 0.012), respectively. By day 7, 38% (95% CI, 25%-54%) of angiotensin II patients discontinued RRT versus 15% (95% CI, 8%-27%) placebo (p = 0.007). Mean arterial pressure response was achieved in 53% (95% CI, 38%-68%) and 22% (95% CI, 12%-34%) of patients treated with angiotensin II and placebo (p = 0.001), respectively. CONCLUSIONS: In patients with acute kidney injury requiring renal replacement therapy at study drug initiation, 28-day survival and mean arterial pressure response were higher, and rate of renal replacement therapy liberation was greater in the angiotensin II group versus the placebo group. These findings suggest that patients with vasodilatory shock and acute kidney injury requiring renal replacement therapy may preferentially benefit from angiotensin II.

Neurogenic pulmonary edema: successful treatment with IV phentolamine.

Neurogenic pulmonary edema (NPE) is a clinical syndrome characterized by the acute onset of pulmonary edema following a significant CNS insult. The cause is believed to be a surge of catecholamines that results in cardiopulmonary dysfunction. Although there are myriad case reports describing CNS events that are associated with this syndrome, few studies have identified specific treatment modalities. We present a case of NPE caused by an intracranial hemorrhage from a ruptured arteriovenous malformation. We uniquely document a rise and fall of serum catecholamine levels correlating with disease activity and a dramatic clinical response to IV phentolamine.