non-specialist management of renal failure - what do i need

Non-specialist Management of Acute Renal Failure

What Do I Need To Know?

Dr Paul StevensConsultant Nephrologist

East Kent Hospitals University Trust

Acute Renal Failure

• 'The abrupt transition from functioning kidneys to kidney function which is unable to accomplish biochemical homeostasis'

RIFLE Criteria

• Risk• Injury• Failure• Loss• End stage kidney

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Acute Kidney Injury Network Criteria

Stage Creatinine Criteria UOP Criteria

1↑SCr ≥ 26.4 μmol/L or

↑SCr ≥ 150-200%< 0.5 mL/kg/hr for > 6 hr

2 ↑SCr > 200-300% < 0.5 mL/kg/hr for >12 hr

3

↑ SCr >300% or

SCr ≥354 μmol/L + acute ↑ ≥44 μmol/L in ≤24hr or

RRT initiated

< 0.3 mL/kg/hr for 24 hr

or

anuria for 12 hr

Pathogenesis

Renal Perfusion

Parenchymal Structures

Urine output

Induce ↓GFR

Pre-renal

Parenchymatous (intrinsic)

Post-renal

Sudden causes affecting

ARF

Called

Acute Renal Failure

Postrenal ARFIntrinsic ARFPrerenal ARF

Acute interstitial nephritis

Acute tubular necrosis

Acute GNAcute vascular

syndromesIntratubular obstruction

What I’m Not Going to Talk About

• Vasopressors• Dopamine agonists• Natriuretic peptides• Adenosine agonists• N-acetylcysteine• Loop diuretics and osmotic diuretics• Prophylactic dialysis/HF

What I Am Going to Talk About

• Everyday life in Margate• Why does it matter?• What’s important?• The real world• Avoiding ARF

Everyday Life in Margate

• 37 year old man, depressed• 1 litre of Brandy, 24 paracetamol, 12

Nurofen plus at c. 18.00 hrs• Vomited, fell asleep against a radiator

and woke up the following morning• Left leg was uncomfortable on waking

and swollen

Why Does it Matter?

• AKI is commoner than many realise• Mortality from AKI remains high• AKI doubles hospital length of stay• AKI predicts subsequent mortality• AKI is costly

ICNARC: AKI Length of StayDays

Severe AKI accounted for 9.4% of all bed days

Survivors

Deaths

17,326/276,731 (6.3%) ICU admissions

Mean age 63.2 ± 15.6 yrs

Kolhe, Stevens, Crowe et al Critical Care 2008;12(Suppl 1):S2 (13 October 2008)

US National Hospital Discharge Survey

• Projected 29,039,599 hospital admissions, 558,032 coded as ARF (1.92%)

Without ARF With ARF

Median age (yr) 58.0 73.0

Median LOS (d) 3.0 7.0

Death (%) 2.3 21.3

Liangos et al. CJASN 2006 Jan;1(1):43-51

The Effect of AKI on Mortality

• 16,248 radiocontrast media procedures• 183 subjects with contrast-media associated AKI• 174 paired subjects (age, procedure, baseline Cr)• Mortality

– 7% in those without renal failure– 34% in those with renal failure

• After comorbidity adjustment renal failure conferred an odds ratio risk of dying of 5.5

Levy, Viscoli & Horwitz. JAMA 1996;275:1489-94

One Year of ARF in East Kent

• 291 patients, 188 male, 103 female• Mean age at presentation 73.1 years• Overall incidence 491 pmp/year• 81 pmp/year received dialysis

Stevens et al, QJ Med 2001;94:553-560

• Survival to discharge from hospital 53%• Survival at 90 days 32%• Survival at 120 months 14%

• In those <65 post-discharge SMR was 14.1

Kolhe et al, Unpublished data

Hamel, M. B. et. al. Ann Intern Med 1997;127:195-202

Cost per QALY of ICU Severe AKI

Acute Kidney Injury and Costs• Consecutive sample of 19,982 adults

• In 1237/9210 (13.4%) SCr ↑ by ≥44 µmol/L• 6.5x risk of death, 3.5d increased LOS

Chertow et al. JASN 2005;16:3365-3370

Unadjusted Age and gender adjusted Multivariably adjusted

What’s Important?Baseline risks Clinical conditions Drugs

Advanced age Sepsis Contrast media

Diabetes Hypotension/Shock Antibiotics

CKD Volume depletion Chemotherapy

Heart failure Rhabdomyolysis NSAIDs

Liver failure Cardiac/vasc surg ACEI/ARB

Male gender Non-renal solid organ Tx

Race/genetic Mechanical ventilation

Low albumin Abdominal compartment syndromeArterial disease

ADQI 4th Consensus Conference

Avoiding Acute Kidney Injury

1. Recognise and assess the patient at risk2. Avoid nephrotoxic agents3. Maintain effective circulatory volume4. Recognise and treat hypoxia 5. Treat infection, avoid nosocomial infection6. Pharmacological manipulation to maintain RBF,

perfusion pressure and GFR

The Patient at Risk From AKICardiovascular Health Study: observational community cohort study5731 patients ≥65 yr at baseline, median follow up 10.2 yr

Haz

ard

ratio

3.9% developing AKI during follow up

Prevalent CVD doubled the risk of AKI

Mittalhenkle et al. Clin J AM Soc Nephrol 2008;3:450-456

UK Demographics

• 60.2 million people• Mean age 38.8 years• 4% Asian• 2% African -caribbean• Diabetes 4%• Hypertension 12.5%• Coronary HD 3.7%• Stroke 1.8%• Heart failure 0.8%

ONS & QMAS data 2005/2006/2007

GFR (ml/min/1.73m2) <30 30–44 45–59

Prevalence 0.38% 1.79% 6.33%

Mean age (yr ± SD) 76.8 ± 14.1 78.4 ± 10.4 69.7 ± 13.5

All CVD (%) 50.7 42.7 27.1

Diabetes (%) 23.0 16.1 12

Hypertension (%) 87.8 86.6 71.4

ACE/ARB (%)* 32.5 37.5 43.0

UK At Risk Population Characteristics

*ACE/ARB prescription in those with hypertension

Stevens et al. Kidney Int 2007 Jul;72(1):92-9

Racking Up The Risk

71

60 59

48

0

10

20

30

40

50

60

70

80

P P /AC E /BF Z D D/AC E /BF Z

GF

R (

ml/m

in)

Juhlin et al, Eur J Heart Fail 2005;7:1049-1056

14 healthy elderly aged 67-78

Single dose of oral Diclofenac (50mg) or placebo

With or without pre-treatment with Enalapril & BFZ

* *******

Assessment of ARF

Key Assessments: All Patients

All 3 Key Assessments

2 of 3 Key Assessments

1 of 3 Key Assessments

No Key Assessments

Stevens et al, QJ Med 2001;94:553-560

Key Assessments: Age ≥70

All 3 Key Assessments

2 of 3 Key Assessments

1 of 3 Key Assessments

No Key Assessments

Stevens et al, QJ Med 2001;94:553-560

Key Assessments: Age <70

All 3 Key Assessments

2 of 3 Key Assessments

1 of 3 Key Assessments

No Key Assessments

Stevens et al, QJ Med 2001;94:553-560

Community Acquired ARF

• 163/291 ARF present at time of admission• 45% were associated with intravascular

volume depletion and/or hypotension • 28% were associated with obstruction• 23% were associated with sepsis• 23% were drug-related

Stevens et al, QJ Med 2001;94:553-560

• 125/291 ARF developed after admission• 55% were associated with intravascular

volume depletion and/or hypotension• 34% were drug-related• 29% were associated with sepsis• 10% were associated with obstruction

Stevens et al, QJ Med 2001;94:553-560

Hospital Acquired ARF

Potentially Avoidable ARF: 101 of 291

ACEI/AII related 56 Aminoglycoside/ Vancomycin toxicity

4

NSAID related 33 Lithium toxicity 2

Volume depletion/ overdiuresis

48 Other 12

Stevens et al, QJ Med 2001;94:553-560

Definitely Avoidable ARF: 54 of 291

ACEI/AII blockers

18 Aminoglycoside/ Vancomycin toxicity

4

NSAIDs 17 Lithium toxicity 2

Volume depletion/ Overdiuresis

19 Lack of recognition of urinary retention Other

7

3

Stevens et al, QJ Med 2001;94:553-560

Primary Instigating Factors for ARF

Vijayan & Miller, Seminars in Nephrology 1998;18:523-32

Drug-related ARF

• Diuretics 99• ACEI 75• NSAIDs 61• Antibiotics 6• Contrast 5

ACEI & diuretics 46NSAIDs & diuretics 24ACEIs & NSAIDs 15ACEIs, NSAIDs & diuretics 8

ARF and Volume Loading

• Korean War– Incidence of ARF 1:200

• Vietnam War– Incidence of ARF 1:600

Acute Kidney Injury: Conceptual Model

Adapted from Himmelfarb et al Clin J Am Soc Nephrol 2008:3;962-967

Fluid Balance Lesson for Surgeons

• “The body is not analogous to a tank into which water can be forced until it finally bursts out through the kidneys”

Lattimer, Lancet 1945

Acute Renal Failure and Sepsis

ARF occurs in– 19% culture positive in

moderate sepsis– 23% culture positive in

severe sepsis– 51% culture positive in

septic shock

70% mortality in sepsis and ARF combined

Rangel-Frausto et al. JAMA 1995;273:117-123

Schrier & Wang NEJM 2004;351:159-69

ARF in East Kent: Initial Assessments

All ARF

n=291

Sepsis & ARF

n=74

Respiratory rate 29% 38%

Oxygen status 30% 49%

Blood culture 42% 66%

MSU 57% 73%

CRP 18% 31%

Stevens et al, QJ Med 2001;94:553-560

Assessment and monitoring: physiological observations

Initial assessment should include at least:

•heart rate•respiratory rate•systolic blood pressure•level of consciousness•oxygen saturation•temperature.

Acutely ill patients in hospital: NICE clinical guideline 50

Change in BP Before Nosocomial AKI

• Non-critically ill patients developing nosocomial AKI in hospital

• Exclusions included ICU patients, absolute hypotension, renal Tx, AKI within 3 days of admission

• Changes in BP prior to maximum stage of AKI assessed

SBP DBP

ΔSBP ΔDBP

**

mm

Hg

Liu YL et al. Nephrol Dial Transplant; NDT advance access 3 September 2008

Avoiding Acute Renal Failure

1. Recognise and assess the patient at risk2. Avoid nephrotoxic agents3. Maintain effective circulatory volume4. Recognise and treat hypoxia 5. Treat infection, avoid nosocomial infection6. Pharmacological manipulation to maintain RBF,

perfusion pressure and GFR

Margate “London-By-The-Sea”

• Presented to A&E 10.30 a.m. seen by Orthopaedic SHO, admitted, NBM in case of theatre, Voltarol analgesia

• Muddy brown urine (once)• Reviewed at 18.40 hrs

– Tachycardic, lying BP of 130/80– Unable to move his left leg, left KJ & AJ

were absent– Medical SHO called

Everyday Life in Margate

• Treated with Parvolex, bloods sent• Results

– Na 138, K 5.2, Urea 19.1, Creatinine 280, Alb 40, AST 1738. Clotting was normal, FBC showed WCC 20.9 (19.3N), Hb 17.8, Plt 247. Paracetamol and aspirin levels were below toxic levels

• Medical registrar reviewed him at 23.15 and noted severe oedema in the left thigh, sensory and motor loss in the left leg and muscle fasciculation

Everyday Life in Margate

Per Ardua Ad Urinam

Acknowledgements:Dr N A TamimiDr M K Al HasaniDr D I ProsserDr P CarmichaelDr N KohleDr B Klebe