John presented to the rural health center with complaints of reduced urine output for the past three days, generalized body weakness, and nausea. He also reports vomiting multiple times over the last two days. He had been feeling unwell for about a week with fever, body aches, and diarrhoea, which began after drinking water from a local river while at work. John has not passed urine in the last 24 hours. There is no significant abdominal pain or history of chronic illnesses.

John has no known history of chronic kidney disease or diabetes. He suffered from malaria a few months ago and was treated with antimalarial drugs. He works long hours in the fields, often without proper hydration, and has been exposed to environmental toxins, including herbicides.

Vital signs: Low blood pressure (90/60 mmHg), pulse 110 bpm, febrile (38.5°C)

General appearance: John appears dehydrated, with dry mucous membranes and poor skin turgor. He is lethargic but responsive.

Cardiovascular and respiratory: Tachycardia with no murmurs; lungs clear

Abdomen: Soft, non-tender, no palpable masses

Extremities: Mild peripheral oedema

Serum creatinine: Elevated (3.8 mg/dL)

Blood urea nitrogen (BUN): Elevated

Electrolytes: Hyperkalaemia, hyponatremia

Urinalysis: Oliguria, no proteinuria, no haematuria

Malaria test: Negative

Liver function tests: Normal

J is diagnosed with acute kidney injury (AKI), likely pre-renal AKI due to dehydration from vomiting, diarrhoea, and poor fluid intake while working in extreme heat conditions. Possible contributing factors include environmental toxins and the consumption of contaminated water.

1. Intravenous fluids (Normal saline): To restore hydration and improve kidney perfusion.
2. Electrolyte correction: Immediate management of hyperkalaemia with calcium gluconate and insulin-glucose infusion.
3. Monitor urine output: With a urinary catheter and serial creatinine measurements.
4. Treat underlying causes: Rehydration and possible antibiotics for presumed gastrointestinal infection if necessary.
5. Referral: If no improvement, transfer to a regional hospital for renal replacement therapy (dialysis).

J’s prognosis will depend on how quickly his kidney function responds to rehydration and correction of electrolyte imbalances.