Oliguria and Fluid Management

ὀλίγος-uria

• Greek prefix “few, little, scanty”

• Two definitions:– Urine output less than 400 cc/day or urine

output or urine output less than 16.6 cc/hr (1) – less than 0.5 cc/kg/hr (2)

• One of the criteria in Acute Kidney Injury

1) Klahr S, MillSB. Acute oliguria. N Engl J Med 1998;338: 671-675

© 2008 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins. Published by Lippincott Williams & Wilkins, Inc.

2

Figure 1.Acute kidney injury.Kellum, John; MD, FCCM

Critical Care Medicine. Acute Kidney Injury in the ICU. 36(4) Suppl:S141-S145, April 2008.DOI: 10.1097/CCM.0b013e318168c4a4

Figure 1. RIFLE criteria for acute kidney injury. GFR, glomerular filtration rate; UO, urine output; dec, decrease; ARF, acute renal failure; ESRD, end-stage renal disease. Used with permission from Bellomo et al (20). *GFR changes are shown for general reference only. The criteria fulfilled by changes in serum creatinine relative to baseline.

Epidemiology

• ARF occurs in approximately 5-8% of hospitalized patients.

• 15-30% of patients admitted to the ICU

• Mortality in ICU patients as high as 60%.

ICU admissions(excluding ESRD)

576

No AKI on admission330

(57.3% of all ICU patients)

Never develop AKI197

(34.2% of all ICU patients)

Ever AKI379

(65.8% of all ICU patients)

AKI on admission246

(42.7% of all ICU patients)

New AKI133

(40.3% of patients withoutAKI on admission)

Partial renalrecovery*

51(13.5% of AKI patients)

Complete renalrecovery*

225(59.4% of AKI patients)

No renal recovery*103

(27.2% of AKI patients)

Garzotto, F, Pasquale P, RIFLE-Based Data Collection/Management System Applied to a Prospective Cohort Multicenter Italian Study on the Epidemiology of Acute Kidney Injury in the Intensive Care Unit. 2011

Oliguria

• A clinical manifestation of:– “perfect” organ function– Kidney injury– Distal obstruction

Oliguria

• Causes of oliguria separated into 3 categories– Prerenal– Renal– Postrenal

 Aetiology of acute renal failure.

Fry A C , Farrington K Postgrad Med J 2006;82:106-116

©2006 by The Fellowship of Postgraduate Medicine

Prerenal Oliguria

“Lack of urine output in the acutely hypovolemic patient is renal success, not renal failure” – Ronald Maier

- The dysfunction is systemic.

- Prolonged renal success can eventually lead to renal failure.

- Responsible for 30-40% of cases of oliguria in the ICU

Oliguria

• Pre-renal conditions– Hypovolemia– Mechanical ventilation– Aortic Stenosis– End-Stage Cardiomyopathy– Drugs that impair auto-regulation

• NSAIDS (ketorolac), ACE-I, ARBs

Pre-renal Oliguria

• Treatment– Treat the underlying cause.

• Prolonged or severe pre-renal conditions can lead to renal injury and oliguric failure.

Renal injury

• Less common than pre-renal ARF

• Three locations of injury:– Glomerulus – Tubules– interstitium