Clinically suspected hypernatremia (12)	Hypernatremia in children is an electrolyte imbalance commonly observed at Dhaka Hospital (11, 24). Before measuring serum electrolytes, patients with hypernatremia can be identified based on history and clinical presentation, for example:History: excessive intake of oral rehydration saline compared with fluid lossSymptoms: excessive thirst, hyper-irritability, inconsolable crying, convulsions (11, 19, 24)Signs: Abnormal mentation, exaggerated deep tendon reflexes, non-pitting edemaLaboratory confirmation: serum sodium ≥150 mmol/L
Sepsis (17)	Sepsis defined according to the following, in the absence of dehydration: Presence of signs and symptoms of inflammation and infection plus Hyperthermia or hypothermia (temperature >38.5°C or <35.0°C, respectively) plus Tachycardia (heart rate: neonates 180 beats per minute (bpm), infants >160 bpm, children age 1–5 years >140 bpm, age >5 years >90 bpm) plus Bounding pulse or altered mental status or hypoxemia in the absence of pneumonia or abnormal white blood count (>12 × 109 cells/L or <4 × 109 cells/L or band and neutrophil ratio ≥0.1) or increased serum lactate level (17)
Oliguria and anuria	Oliguria defined as urine output <1 mL/kg per hour in infants; in children and adults, urine output <0.5 mL/kg per hour for >6 hours (19, 25)Anuria defined as no urine output >12 hours
Treatment of dehydrating diarrhea	WHO guideline for treating dehydrating diarrhea (26)
Severe pneumonia (WHO classification) (15)	Infants with age-specific fast breathing and severe lower chest wall indrawing, with any feeding difficulty or abnormal mentation or convulsion or gruntingSuspected patients confirmed with chest X-ray