Acute kidney injury after abdominal surgery: Risk factors and management

Runolfur Palsson, M.D., FACP, FASN Landspitali–The National University

Hospital of Iceland University of Iceland

11 March, 2017

Nothing to disclose

Disclosures

AKI affects around 13% of patients undergoing major abdominal surgery and on average its occurence is associated with a 12-fold crude risk of dying in the

postperative period

Random effects model meta-analysis of proportion of patients developing

post-operative AKI

O´Connor et al., Intensive Care Med 2016;42:521–30

Random effects model meta-analysis of the effect of AKI

diagnosis on short-term survival

O´Connor et al., Intensive Care Med 2016;42:521–30

Long et al., Anesth Analg 2016;122:1912–20

Flow diagram of patients undergoing

abdominal surgery

Survival of patients with AKI compared with a control group

Survival of patients with stages 1, 2, and 3 AKI (n = 247)

compared with a propensity score-matched control group (n

= 247)

Long et al., Anesth Analg 2016;122:1912–20

Patients with AKI had greater 30-day mortality

(18.2% vs 5.3%; P < 0.001) compared with propensity

score–matched controls

Patient Operative Pharmacological

Advanced age Emergency surgery NSAIDs

Male sex Cardiac surgery ACE inhibitors or ARB’s

Chronic kidney disease Liver transplant surgery Aminoglycosides

Chronic heart failure Vascular surgery Calcineurin inhibitors

Hypertension Intraperitoneal surgery Hydroxyethyl starch solutionsChronic liver disease Duration of surgery Radiologic contrast agents

Diabetes mellitus Major hemorrhage

Sepsis Blood transfusion

Limited cardiorespiratory

Intraoperative hypovolemia and

Modified from: Gross et al., BJA Education 2015;15: 213–18

Risk factors for perioperative AKI

The elderly are proneto kidney injury

• Multiple comorbid conditions are frequently present

• Age-related changes in the kidney, systemic vasculature and immune system

• Vasodilatory increase in renal blood flow and GFR is markedly reduced

• Renal adaptation following acute ischemia is compromised

Bonventre & Yang, J Clin Invest 2011;121:4210–21

SG >1.020 <1.010Uosm >500 <350UNa <20 >40FENa <1% >1%Purea/Cr >20/1 10-15/1U/PCr >40 <20

Prerenal azotemia ATN

Urinary indices in acute kidney injury

Implementing NICE guidance www.nice.org.uk

NICE Pathways

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• Identify patients at risk – Advanced age, comorbid conditions, ASA score – Surgical procedure

• Provide meticulous preoperative and perioperative care – Maintain hemodynamic stability (avoid MAP <60

mmHg) – Correct hypovolemia – Avoid blood loss and unnecessary blood

transfusion – Avoid nephrotoxic drugs

Measures to prevent perioperative AKI

• Maintain hemodynamic stability (MAP >65 mmHg) – Fluid – Vasopressors

• BP target depends on age and co-morbid conditions, particularly hypertension

• Crystalloids rather than colloids are recommended for volume expansion

• Avoid fluid overload • Diuretics should not been used, except for the

management of volume overload • Correct metabolic derangements • Adjust drug doses • Provide adequate nutrition

Management of AKI

• The ability of fluid loading to protect the kidney from injury remains unproven

• Excessive fluid administration can induce organ edema that may result in renal injury

• The optimal choice of fluid for patients at risk or with established AKI remains uncertain

• Colloid solutions containing hydroxyethyl starch (HES) are associated with increased risk of AKI and should not be used

• Fluids with a high chloride content, such as isotonic saline, may decrease renal perfusion and GFR

Fluid resuscitation

Cumulative fluid balance in AKI

survivors and non-survivors in the

first 3 days of their ICU stay

Wang et al., Crit Care 2015;19:371

Mean ± SE **P < 0.001

Fluid balance and mortality in critically ill patients with AKI: A multicenter prospective epidemiological study

Wang et al., Crit Care 2015;19:371

Mortality rate by fluid

accumulation in 3 days relative to

baseline weight in patients with AKI

SAFE Study Investigators, N Engl J Med 2004;350:2247–56

Comparison of albumin and saline for fluid resuscitation in

ICU patients

Serpa Neto et al., Crit Care 2014; 29:185.e1–185.e7

Acute kidney injury in patients managed

with HES or crystalloid:

systematic review and meta-analysis of

the literature

Shaw et al., Ann Surg 2012;255:821–829

Major complications, mortality, and resource utilization after open abdominal surgery

0.9% Saline compared with Plasma-Lyte

Odds ratios and 95% confidence intervals

for prespecified clinical outcomes

Yunos et al., JAMA 2012;308:1566–72

Development of stage 2 or 3

AKI in ICU patients

Chloride-liberal vs chloride-restrictive intravenous fluid

administration strategy and AKI in critically Ill adults

Censoring at hospital discharge or death

The SPLIT Trial: effect of a buffered crystalloid solution vs saline on AKI among patients in

the ICU

Young et al., JAMA 2015;314:1701–10

Cumulative incidence of

patients requiring RRT until day 90

after enrollment

Meta-analysis of frusemide to

prevent or treat acute renal

failure

Ho & Sheridan, BMJ 2006; 26;333(7565): 420

Implementing NICE guidance www.nice.org.uk

Nephrology referralNephrology: Discuss AKI management with a nephrologist/paediatric nephrologist as soon as possible (and within 24 hours) if one of the following is present:

Potential diagnosis requiring specialist treatment (for example, vasculitis or glomerulonephritis)

AKI with no clear cause

Inadequate treatment response

Complications associated with AKI

Stage 3 AKI eGFR is less than < 30 ml/min/1.73 m2 after AKI episode

Patients with renal transplant and AKI

CKD stage 4 or 5

Renal replacement therapy: Refer adults, children and young people immediately for RRT if any of the following are not responding to medical management:

Hyperkalaemia Metabolic acidosis

Symptoms or complications of uraemia such as pericarditis or encephalopathy

Fluid overload +/- pulmonary oedema

• AKI is common after abdominal surgery • AKI is associated with significant morbidity and

mortality • Meticulous preoperative risk assessment and

perioperative management are important preventive strategies

• Careful management of fluid balance, maintenance of hemodynamic stability and avoidance of nephrotoxic insults are key therapeutic measures

Summary

Thank you! runolfur@landspitali.is