PERI-OPERATIVE

RENAL

DYSFUNCTION

Dr. M.M.PANDITRAO

CONSULTANT DEPARTMENT OF ANAESTHESIOLOGY &

INTENSIVE CARERAND MEMORIAL HOSPITALFREEPRT, GRAND BAHAMA

COMMONWEALTH OF THE BAHAMAS

PERI-OPERATIVE RENAL DYSFUNCTION

Peri-operative Acute Renal Failure

i. Pre-existing pre-op risk factor

ii. Intra-operative event

ESRD /CRF Patient requiring care

POARF : Principles

• Pre-disposing pre-op risk factors

• Physiology of Urine Production

• Differentiate and Manage causes

• Effects of Anaesthetics and Surgery

• Prevent insults of these on Kidneys

RISK FACTORS

• Systemic Diseases: CRF, DM,• Jaundice• Advanced Age• Poor Myocardial Function• Nephro-toxic drugs: recently used• On CPB

•

PHYSIOLOGY OF URINE PRODUCTION

AETIOLOGY OF POARF

• Pre-Renal

i. Ac.hypovolemia & hypotension

ii. Poor cardiac function

iii. Hepatic Failure

• Post-Renal : Obstructive Pathology

AETIOLOGY OF POARF ( CONTD.)

• INTRINSIC ARF (RENAL)

i. Prolonged ischemia: aortic cross-clamping

ii. Myoglobinuria

iii. Haemoglobinuria : transfusion reaction

iv. Nephro-toxics

v. Renal Artery Thrombosis/ embolism

vi. Renal Vein Thrombosis

vii. Interstitial Nephritis/ Ac. GN/ Vasculitis

PATHOPHYSIOLOGY OF RENAL ISCHEMIA

RENAL ISCHEMIA

>Decreased renal perfusion

Hypoxic injury to renal tubules

Tubular endothelial swelling

Vascular congestion within outer medulla

Sloughing of tubular necrotic debris

Tubular obstruction

Increased backpressure in Bowman’s capsule

decreased GFR increased backleak of ultra-filtrate

OLIGURIA

Diagnosing aetiology of ARFurinary indices of ARF

• *FeNa = Urine Na/ Plasma Na X 100 ** RFI = Urine Na Urine creat/ Plasma Creat Urine creat/ Plasma creat

PRE INTRINSIC

Urine Na+ (meq/ lit.) <20 >40

Urine Osmo.(mosm/ lit.) >500 <350

Fractional excretion of Na ( FeNa)*

<1 >2

Renal Failure Index(RFI)** <1 >2

Urine sediments Clear/ casts

Brown granular casts

Management of Intra-op Oliguriaprevention & treatment

• Euvolemic state + stable haemodynamics• Patent Foley and adequate BP• CVP• Review Blood loss• Expand Blood volume• PA catheter & PCWP• Check Hb / Haematocrit / Urine for indices

Management of Intra-op Oliguriaprevention & treatment ( cont.)

• If no Invasive --- 2 simple tests• Inspite of Volume loading low C. O.

Dopamine / Dobutamine / adrenaline• Loop Diuretics• Mannitol ?????• Under Trial : ANP & Urodilatin• Vasoactive renal protective drugs:

PGs, Endothelin antagonists, Theophylline,

Calcium Channel Blockers

PERIOPERATIVE MANAGEMENT OF

ESRD/ CRF

End Organ Effects of ESRD NS – Uremia : sedation, fatigue, encephalopathy - Ch. Dialysis : dementia, dialysis diseqilibrium ** Sensitivity to sedatives/hypnotics/IVAs/ Inhalationals - Uremia : Peripherral & autonomic neuropathy*** autonomic Neuropathy - Haemodynamic instability$$ Medico-legal implications CVS – Hyperlipidemia—atherosclerosis ---

hypertension—DM---IHD/ LVH/ LVF/ CHF Pericarditis “Leaky Pulm. Capillary Syndrome”--- Pulm.Oedema

End Organ Effects of ESRD (cont.)

• BLOOD: Anemia, Platelet dysfunction,

Blood Transfusion – Caution

Uremic toxins• ELCTROLYTES: K+

: Ca+, PO4---, Bone

“Renal Osteodystrophy”• ACIDOSIS : HCO3

- ???

• INFECTIVE : A-V Grafts / antibiotics

Hepatitis

Pre-op. Concerns of ESRD

• Strict evaluation of End-Organ damage

• Review of last Dialysis record

• Review of Aetiology of C R F

• Avoid K+ containing I V fluids : R L

• Review recent electrolytes, urea.

Creatinine

• Care and safety of A V Fistula

Intra-operative

• INDUCTION: Sensitivity to IVAs, etc.

multifactorial --- * hypoproteinemia

* uremia

* Free active metabolites

* Met.acidosis… free fraction

Dose, Route, Speed, Concentration etc. of Inj.

Intra-operative (cont.)

• INTRA-VASCULAR VOLUME• AUTONOMIC NEUROPATHY• L V DYSFUNCTION• INHALATIONALS• OPIOIDS• NMBDs : Benzylisoquinoliniums

Vs.

Amino-steroids

Succinyl Choline

Post-operative

• Reversal• Ventilatory Support ????• Nursing Care

CONCLUSION

• RENAL DYSFUNCTION IS A PROBLEM• ESPECIALLY PERI-OPERATIVE ARF• UNDERSTANDING AETIO-PATHO• DIAGNOSING THE CAUSE• INVESTINGATING & MANAGING• ESRD / CRF VERY CHALLENGING