5.10 Management and prevention of complications

5.10.1 Hypoglycaemia

Hypoglycaemia is a potential complication in patients who start drinking ORS (which contains glucose) late and/or do not quickly resume nutrition. Those most at risk are the malnourished and children under 5 years.

Clinical signs

– Suspect hypoglycaemia:
• On admission: in patients with decreased levels of consciousness or hypotonia persisting after 2 boluses of RL.
• During rehydration therapy: if neurologic signs (lethargy or coma) appear when signs of dehydration are resolving.
• In case of hypothermia.
– A blood glucose level < 60 mg/dl (< 3.3 mmol/litre) indicates hypoglycaemia.


– Administer glucose by slow IV injection:
Children: 5 ml/kg of 10% glucose1
Adults: 1 ml/kg of 50% glucose
– Reassess glucose level after 30 minutes and repeat the same dose if necessary.
– To prevent relapse, give ORS under observation. If ORS consumption is delayed or reduced: add 100 ml of 50% glucose per litre of RL to be used for rehydration (giving a 5% glucose solution) until sufficient ORS intake is possible.


Start ORS therapy as soon as possible for patients receiving IV treatment and resume rapidly nutrition for all patients.

5.10.2 Hypokalaemia

The patients most at risk to develop symptomatic hypokalaemia are:
– Patients treated by RL but who receive little or no ORS and do not resume early feeding;
– Malnourished children, who tend to suffer from chronic potassium depletion.

Clinical signs

Hypokalaemia causes the dysfunction of skeletal muscles, smooth muscles (intestines, bladder), and cardiac muscle (conducting system). Typically, symptoms appear in a patient who has been under IV rehydration for at least several hours.
– Moderate hypokalaemia: generalized fatigue, muscle cramps and weakness, abdominal distention, or urinary (bladder) obstruction.
– Severe hypokalaemia: breakdown in skeletal muscle, tetany, ascending paralysis, respiratory difficulties, and cardiac arrhythmias (irregular heart rate, palpitations).

At admission, it is common that a dehydrated patient complains of muscle cramps. It is more likely that these are due to dehydration rather than hypokalaemia. The cramps should normally resolve with rehydration, and there is no need to treat them other than giving ORS.

Only the rare patients who arrive with obvious clinical signs of hypokalaemia should be treated immediately.
If the symptoms of hypokalaemia appear several hours after admission, treatment should be based on the severity of the symptoms.


The objective of treatment is not to normalize serum potassium (it will correct with resumption of a normal diet) but to minimize the systemic effects of hypokalaemia.

– Moderate hypokalaemia
Use 7.5 % potassium chloride syrup (1 mmol of K+/ml) PO2 :
Children under 45 kg: 2 mmol/kg (2 ml/kg) daily
Children 45 kg and over and adults: 30 mmol (30 ml) 3 times daily 
For dosage charts, see Appendix 7.

The duration of treatment depends on clinical evolution. The decision whether to continue treatment should be re-evaluated after clinical examination. Treatment of 1 to 2 days is usually sufficient if the patient can drink ORS and eat.

– Severe hypokalaemia
IV potassium is given by medical prescription, under medical supervision (Appendix 8) and only after a clinical examination has confirmed signs of severe hypokalaemia.


ORS is designed to replace the potassium lost in diarrhoea. In the absence of dehydration or in patients with some dehydration, ORS is sufficient to prevent symptomatic hypokalaemia if it is taken in sufficient quantity to rehydrate the patient. In those patients being rehydrated by the IV route, giving ORS at the same time reduces the risk of symptomatic hypokalaemia.

5.10.3 Renal failure

Acute renal failure may occur when severe dehydration results in kidney under-perfusion. Patients with diabetes and hypertension, as well as the elderly, are at greater risk.

Clinical signs

Persistent oliguria or anuria despite adequate rehydration


The main goal is to prevent further kidney injury by maintaining a normal fluid balance and avoiding other nephrotoxic drugs (e.g. acid acetylsalicylic, ibuprofen, aminoglycosides), while allowing time for renal function to improve, which can take hours to days.

It has not been proven that furosemide can restore kidney function. It is recommended only if renal failure results in volume overload causing pulmonary oedema.

If oliguria or anuria persists after the diarrhoea has ended, further hospitalisation may be needed where more specialized care can be provided.

5.10.4 Fluid overload

Fluid overload is a complication of IV rehydration, usually resulting from an error in administration (too much fluid, overly rapid infusion).
However, fluid overload can occur even with normal rehydration treatment in infants, the elderly, and patients with severe malnutrition or cardiovascular disease.
Patients receiving ORS alone do not develop signs of over-hydration.

Clinical signs

– Peripheral oedema: the appearance of peri-orbital or lower limb oedema may indicate fluid overload.
– Pulmonary oedema: rapid breathing, dyspnoea, cough (first dry, then wet), and crepitations on lung auscultation.

Pulmonary oedema may be preceded by peripheral oedema but this is not always the case.


– Peripheral oedema
• Do not take out the catheter; reduce the infusion rate to a minimum (keep vein open).
• Re-evaluate the level of dehydration and the necessity of continuing IV rehydration (signs of dehydration no longer present? able to switch to oral rehydration?).
• Auscultate the lungs.
• If the patient still needs IV rehydration therapy, resume the infusion at a slower rate and observe more closely, assuring that dehydration does not worsen.
• Peripheral oedema alone does not require treatment with furosemide. The oedema will resolve spontaneously within 24 to 48 hours.

– Acute pulmonary oedema
• Do not take out the catheter; reduce the infusion rate to a minimum (keep vein open).
• Have the patient sit upright with their legs over the edge of the bed.
• Auscultate the lungs.
• If the patient is dyspnoeic, administer furosemide IV:
Children: 1 mg/kg
Adults: 40 mg

These measures should lead to an improvement in clinical signs over 30 to 60 minutes.
Examine the patient for other contributing factors such as cardiovascular (severe hypertension) or renal (anuria) disease and rule out pulmonary infection.
Once the patient is stabilized, reassess the level of dehydration. Based on the clinical signs, change to oral therapy or continue the IV therapy at one-half the previous rate, while maintaining close observation and stopping IV treatment as soon as possible


– Avoid unnecessary IV infusions.
– Avoid prolonging IV infusions in patients who are no longer in need.
– In at-risk patients (chronic hypertension, cardiac disease), pay particular attention to IV volume and infusion rate as well as the clinical evolution while under IV therapy.

Ref Notes
1 If 10% glucose is not available, use 50% glucose (1 ml/kg) diluted in 4 ml/kg of RL or 0.9% sodium chloride.
Undiluted 50% glucose solution is too viscous to be injected to children.
2 For adults, an alternative is to give the IV preparation of potassium chloride (KCl) by oral route: 26.8 mmol (two 10 ml ampoules of 10% potassium chloride, 13.4 mmol/ampoule) 2 to 3 times in one day. This treatment is only for adults. The taste is rather offensive, mix in cool water or flavoured drink (e.g. juice).