Acute or chronic impairment of renal function

Causes

• Compromised renal perfusion eg. dehydration, heart failure, shock
• Obstructed urinary flow
• Damage to renal tissue

Clinical features

• Oliguria (urine flow <1mL/kg/hr)
• Generalised oedema
• Heart failure, hypertension
• Hyperkalaemia
• Nausea and vomiting
• Lethargy
• Dyspnoea
• Convulsions
• Encephalopathy
• Anorexia

Differential diagnosis

• Other renal disorders

Management (adults and children)
HC4

As dialysis facilities are limited to referral hospitals, the initial management is conservative to support the patient and maintain body biochemistry as near normal as possible until renal function recovers

Acute

Monitor fluid input and output.

- daily fluid requirements = 10mL/kg + total of losses through urine, vomitus and diarrhoea

Monitor BP twice daily

Daily weighing

Restrict salt intake (<2g or half teaspoonful daily)

Restrict potassium intake eg. fruit, vegetables, meat, fizzy drinks

Restrict protein intake

Ensure adequate calories in diet

Check urine and electrolytes frequently

Treat any complications (eg. infections, hypertension, convulsions) adjusting drug dosages according to the clinical response where appropriate

Note

Do not give any drugs which may make kidney damage worse - see section 13.6.1 below

If no response to above general measures:

Refer for specialist management including possible peritoneal dialysis as soon as possible and before the patient’s condition becomes critical

Chronic

Permanent impairment of renal function due to progressive damage to the renal tissue

Refer for specialist management

Prevention

• Early, effective treatment of throat, skin and urinary tract infections

13.6.1 USE OF DRUGS IN RENAL FAILURE

• Be very careful when prescribing any drug and check available prescribing information (eg. in BNF) regarding use in renal failure/impairment

• Many drugs are excreted through the kidneys and accumulate when urinary output is reduced

• Some drugs are presented as sodium or potassium salts and contribute to accumulation of these electrolytes

• With life-threatening infections (eg. meningitis), use normal or high doses of antibiotics initially and then reduce doses once the condition has responded

a) Drugs which are usually safe

doxycycline
erythromycin
benzylpenicillin (max 6g daily in severe impairment)
phenytoin
rifampicin

b) Drugs to use with care in reduced doses

ACE inhibitors (eg. captopril)
amoxicillin
chloramphenicol (avoid in severe impairment)
ciprofloxacin
cotrimoxazole
diazepam
digoxin
insulin
isoniazid-containing medicines
pethidine (increase dose interval, avoid in severe impairment)
phenobarbitone r propranolol

c) Drugs to avoid using

aspirin and other NSAIDS eg. ibuprofen, indomethacin
codeine
ethambutol
gentamicin
nalidixic acid
nitrofurantoin
streptomycin