Download ACUTE RENAL FAILURE IN SEVERE MALARIA

ACUTE RENAL FAILURE IN
SEVERE MALARIA
Dr Saroj K Mishra
Dr Kishore C Mahanta
Ispat General Hospital, Rourkela Orissa India
INTRODUCTION
• Malaria is one of top 10 killer diseases in world
• ARF occurs in <1% of pf malaria, but mortality up to
45%
• Common in adults than children, recent trends- high
incidence
• Diagnosed when sr. creat.>3mg/dl or urine output
<400ml/24 hrs
• Renal involvement varies from mild proteinuria to
severe azotemia
• Malarial ARF is associated with CM, Jaundice,
Anaemia, ARDS/Pulm. edema & Hypoglycaemia
INTRODUCTION Contd.
Two different settingsa) ARF as a component of MOF – present at the
time of admission,
Often associated with poor prognosis.
b) Present as a sole complication at a later stage
of the course, when other complications
subsided or treated,
Often associated with recovery.
Pathology & Pathogenesis
• In mild cases- not much change in renal
parenchyma- may be minimal tubular
degeneration, mild renal parenchymal
change & presence of vacuoles
• In severe cases- Tubular degeneration with
distal tubular necrosis, Proximal tubules are
often loaded with malarial pigments, Hb
granules may be seen in the tubular cells
Pathology & Pathogenesis 2
• Most patients have little or no proteinuria &
urinary sediment contains occasional granular
and hyaline cast but no RBC.
• Absence of hypertension, Rapid resolution
without residual impairment & predominant in
adults rather than children with urinary
findings suggests- ARF results from ATN &
not glomerulonephritis
Pathology & Pathogenesis 3
• ARF- mediated thro’ several mechanisms
1.Effect of pRBC on microcirculation- knob like
processes formation on surface of RBC which
helps in anchoring the endothelium
Cytoadherence- due to thrombospondin formation
from vascular endothelium- specific to pf ( not in
pv/pm) so ARF only in pf.
Loss of deformability of pRBC according to need of
microcirculation- slugish circulation- renal
ischemia
Pathology & Pathogenesis 4
2.Hypovolumia may occur due to Fever
(hyperpyrexia), sweating, decreased intake of
fluid, vomiting etc.
3.DIC
4.Increased plasma viscosity due to infection
5.Release of chemical mediators- TNF,cachectin,
cytokines, interleukines etc causesvasoconstriction, increased vascular permiability,
catecholamine release(SIADH )
hemoconcentrarion, shock & tubular necrosis
6.Hyperbilirubinaemia due to hemolysis, Black
water fever in G6 PD deficiency patients is also
associated with ARF
CLINICAL FEATURES
ARF in severe malaria is common in adults, rare in children
Two subsets of presentationsa. ARF as a component of multi organ failure
present since admission- poor prognosis,
associated with anemia, jaundice, hypoglycemia,
acidosis or coma
b. Present as a sole complication- appears at a later
stage when other complications subsided/treated
– prognosis is good
CLINICAL FEATURES 2
• Diagnosis suspected when urine output <400ml/24
hrs & confirmed when sr.creatinine >3mg/dl in
adults & >1.5mg/dl in children
• Patient may be anuric, oliguric, with normal
urination or polyuric
• Oliguric phase varies from few days to wks
• Prerenal azotemia presents with signs of
dehydration
• Prolonged anuria/oliguria – volume over load due
to decrease salt & water excretion
CLINICAL FEATURES 3
•
Differentiation of prerenal & established
ARF is important for management- sp.gr.of
urine is >1.020 & <1.010 respectively
• Vulnerable group of patientsa) Pregnant women, b) high parasitemia,
c) very high jaundice d) prolonged dehydration
e) on NSAID therapy
• Patients with pfr +ve to be screened for
ARF
CRITICAL DETERMINANTS
•
•
•
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•
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Hypo & hyper volumia
Hyperparasitemia
Hemoconcentration
Hyperbilirubinemia
Hyperpyrexia
Hyperkalemia
Hyponatremia
LAB. INVESTIGATIONS &
MONITORING
• Peripheral smear for diagnosis & parasite
clearance
• Blood urea, creat., bilirubin, SGPT, Na,K,
HCO3,PH
• Urine sp. Gr.
• ECG & chest X-ray when indicated
TREATMENT (Guidelines)
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Appropriate antimalarial at the earliest
Maintenance of fluid & electrolytes
Recording of intake output chart
Prevention of fluid overload & secondary
infection including pneumonia
• Treatment of acquired infection at the
earliest keeping an open mind
TREATMENT 2
• Meticulous record of fluid requirementfluid intake, urine output –guides the
administration of fluid, monitoring the
improvement & most of all preventing fluid
overload – a CVP line can be established
• Daily sr creat estimation in severe pf
malaria cases if possible
TREATMENT 3
• If the 24hr urine output is <400ml & the
patient is clinically dehydratedFluid challenge –
20ml/kg of Normal saline over one hr.
Monitor for fluid overload after each 200ml
by- Chest auscultation, JVP,CVP at 0 & +5
Urine output should be 20ml/hour
TREATMENT 4
• If no urine after fluid therapyDiuretic challenge:
Iv loop diuretic- Inj Furosemide in incremental dose
40-100-200-400mg at ½ hour interval
• If no improvementDopamine challenge:
Inj dopamine slow iv infusion at
2.5 to 5mcg/kg/min
RESPONSE
• 75%of oliguric & 5%of anuric responds
with increased urine output
• No improvement in sr creat level
• False sense of improvement
• Reduces the risk of volume overload
• If ineffective further fluid is restricted
CAUTION
•
•
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No benefit in oliguric patients
No recovery in anuric patients
Delay in decision for dialysis
Complications of Dopamine- Gangrene,
Ototoxicity
CAUTION 2
Avoid Nephrotoxic drug in ARF suspects• ACE inhibitors & cyclooxygenase
inhibitors (NSAIDs)- precipitate prerenal
azotemia to ischemic ARF
• Cephalosporines & Aminoglycosides
• Assesment of renal function using urine
output is dangerous in patients receiving
Diuretics
Antimalarial Drugs
•
•
-
Qunine
Can be given safely in pregnancy & ARF
Initial dose of qunine -10mg/kg 8hrly
Reduction after 48 hrs
No dose adjustment during HD
Artemisinine
No modification is required in ARF
Indications for Dialysis
Clinical :
• Uraemic symptoms- Nausea, Vomiting, Hiccough,
Flapping tremors, Muscle twitching,& Convulsion
• Fluid overload
• Pericardial rub
• Arrhythmia
Laboratory: Rising creatinine, Hyperkalemia,
(K >6.5), Acidosis(HCO3 <15meq/l)
Haemodialysis
• Advantages
- Efficient method
• Disadvantages
- Only in selected centers
- Expertise
- Lag time
Caution for conservative management
of ARF in severe malaria
• May develop critical signs at any odd hrs
without giving a scope for dialysis
• Many patients have been lost as dialysis is
decided but institution is delayed
• Sudden cardiac death may ensue in a patient
who is improving due to pulmonary edema or
hyperkalaemia
PROGNOSIS
• Mortality among renal failure is 45% to
10% those without
• Death increases 3 fold in presence of ARF
• Very high mortality in presence of MOF
• Mortality can be reduced to 10% if early &
frequent Dialysis is instituted
• Survival with PD is lower than HD