Practical skills in pediatrics: common pediatric emergencies

Figure .Causes of acute kidney injury

GBM, Glomerular basement membrane.

Functional ARF is a temporary impairment/disturbance of some renal functions that has a reversible development during conservative therapy.

Organic ARF has no reversible development without the use of extracorporeal methods of treatment and is characterized by a wider range of impaired renal functions.

From the moment of making the diagnoses (ARF) to the patient the following actions are carried out:

• eliminate the factor that led to the development of ARF;
• prescribe a carbohydrate salt-free diet and special foods;
• perform a test to restore diuresis;
• determine the indications for dialysis;
• apply symptomatic therapy.     

Treatment of the underlying/main disease

          The caloric diet content of patients with ARF should be 25-35 kcal/kg/day, amino acids – up to 1.7 g/kg/day, vitamins and microelements if needed. It is suggested to prescribe 0.8-1.0 g/kg/day of protein to patients with ARF who do not require dialysis; 1.0-1.5 g/kg/day for ARF patients receiving renal replacement therapy (RRT) and up to 1.7 g/kg/day for continuous RRT patients and for hypercatabolic patients. It is recommended to provide food mainly by enteral administration.

          The test for the restoration of diuresis is performed at BP > 60 mm Hg., in the absence of hyperhydration in terms of increased CBV and decreased hematocrit and lack of urine in the bladder according to ultrasound.

          At first, an intravenous infusion of 20 ml/kg of 0.9% saline solution or 5% albumin (human) solution is performed for 30-60 minutes. Then a 2.4% solution of euphyllin is administered iv at the rate of 1 ml/10 kg of body weight and sequentially 2-7 mg/kg of furosemide. In the absence of urination recovery within 1.5-2 hours, re-administered furosemide (torcemide is more preferable, taking into account less toxic effect on the kidneys) until the total dose for two injections is not more than 15 mg/kg.

          In the absence of a diuretic effect, titrated administration of dopamine (dobutamine) is made in a renal dose of 1.5-3.5 μg/kg/min round-the-clock. The criterion for the adequacy of the selected dose is the absence of hypertension. The duration of the drug administration is determined by the initiating of dialysis. In the absence of such possibility for social or medical reasons, the use of dopamine can be successfully continued non-stop. To restore diuresis, it is possible to use ACE inhibitors and ARBs II.

          In case of impossibility of pharmacological restoration of diuresis the following indications for dialysis are determined:

Symptomatic therapy. The initial stage of ARF. The prescription of renal doses of dopamine (1.5-2.5 μg/kg/min) is evident only in the first day.

Hypovolemia, shock: CBV recovery (10% glucose solution, 0.9% saline solution according to generally accepted principles). Stimulation of diuresis – 15% solution of  mannitol   0.2-0.4 g/kg (dry matter) iv drip. In the absence of diuresis increase after administration of 1/2 dose, its further administration is contraindicated, also in case of heart failure and hypervolemia.

To prevent hyperhydration, it is necessary to limit liquid intake (per day = loss of perspiration 25 ml/kg + excreted urine), to restrict the injection of sodium with food or parenterally. But 1/5 of the liquid IV – sodium bicarbonate solution and in extreme cases – 0.9% saline solution.

With normovolemia: 2% solution of  furosemide 2 mg/kg, IV, if there is no increase in diuresis after 2 hours, – repeat in double dose; in order to enhance the diuretic effect of  furosemide  simultaneously iv inject titrated dopamine: 1-4.5 μg/kg/min.

Drugs to improve renal blood flow: 2.4% solution of euphyllin – 1.0 ml/years old IV; 2% solution of trental at a dose of 1-2 mg/kg IV, 0.5% solution of dipiridamol – 3-5 mg/kg IV.

Both crystalloids and often colloids are used to restore hemodynamics.

Oligoanuric stage of ARF. Diet: proteins are excluded, carbohydrates are given to prevent excessive catabolism and accumulation of nitrogen metabolism. The diet is poor in protein –10 days. Then 1 g/kg of protein is added to a diet.

 Conservative treatment in the absence of indications for hemodialysis:

1. The amount of liquid per day = diuresis of the previous day + loss of perspiration + extrarenal loss;

• loss of perspiration 25 ml/kg/day (in newborns – 1.5 ml/kg/hour, up to 5 years – 1 ml/kg/hour);
• external losses: defecation and vomiting –10-20 ml/kg/day, for every 10 respiratory movements > norm – 10 ml/kg/day, for every degree t > 37º – 10 ml/kg/day.

In the presence of vomiting, 60-70% of the daily volume of liquid is given orally, the latter intravenously. Infusion therapy is performed with glucose-saline solutions (1/5 of the volume – rheopolyglucin).

Contraindications with anuria: protein preparations, solutions containing potassium ions (Ringer's solution, potassium chloride).

2. Correction of metabolic acidosis:

• gastric and intestinal lavage with 2% solution of soda (Na2CO3),
• sodium bicarbonate solution IV. The dose is calculated by the formula: