Glycogen storage disease type I (GSDI) is an uncommon condition resulting from a deficiency or absence of glucose-6-phosphatase, a key enzyme in regulating blood glucose levels. In this report, we describe a two-month-old girl diagnosed with GSDI who presented to the emergency department in a tertiary care hospital for irritability, excessive crying, and hyperventilation. She was found to have hepatomegaly and hypoglycemia. Laboratory investigations showed high levels of triglycerides, lactic acid, uric acid, and calcium. The combination of hypertriglyceridemia, hypoglycemia, and hepatomegaly should alert neonatologists and pediatricians to consider GSDI in the diagnosis. Hypercalcemia arose as an unknown problem in GSDI patients and should be considered during acute attacks.

Methylmalonic acidaemia (MMA) and propionic acidaemia (PA) are very rare autosomal recessive inherited metabolic diseases from the group of organoacidopathies. Katabolism due to minor infections can lead to metabolic decompensation including hyperammonemia and ketoacidosis, especially in small children. We present data from a small cohort to clarify whether placement of a percutaneous endoscopic gastrostomy with jejunal tube (J-PEG) reduce metabolic imbalances and hospital stays. The aim is to prevent emergencies from occurring by preventing metabolic derailments at an early stage. 4 patients with MMA (N = 3) or PA (N = 1) were included. Data were collected at every investigation, in particular pH value, pCO2, bicarbonate, base excess, ammonia and lactate. Due to repeated metabolic derailments, a percutaneous endoscopic gastrostomy was placed for postpyloric nutrition. In conclusion, placement of a percutaneous endoscopic gastrostomy with postpyloric tube appears to reduce the rate of metabolic decompensations. In addition, hospital stays and especially the number of treatment days can be reduced. This method, especially the placement of a postpyloric tube could enable parents to prevent catabolism when vomiting begins by continuously feeding through the jejunal part, as a step to prevent a metabolic emergency from occurring.

The \'classic\' organic acidaemias (OAs) (propionic, methylmalonic and isovaleric) typically present in neonates or infants as acute metabolic decompensation with encephalopathy. This is frequently accompanied by severe hyperammonaemia and constitutes a metabolic emergency, as increased ammonia levels and accumulating toxic metabolites are associated with life-threatening neurological complications. Repeated and frequent episodes of hyperammonaemia (alongside metabolic decompensations) can result in impaired growth and intellectual disability, the severity of which increase with longer duration of hyperammonaemia. Due to the urgency required, diagnostic evaluation and initial management of patients with suspected OAs should proceed simultaneously. Paediatricians, who do not have specialist knowledge of metabolic disorders, have the challenging task of facilitating a timely diagnosis and treatment. This article outlines how the underlying pathophysiology and biochemistry of the organic acidaemias are closely linked to their clinical presentation and management, and provides practical advice for decision-making during early, acute hyperammonaemia and metabolic decompensation in neonates and infants with organic acidaemias.
The acute management of hyperammonaemia in organic acidaemias requires administration of intravenous calories as glucose and lipids to promote anabolism, carnitine to promote urinary excretion of urinary organic acid esters, and correction of metabolic acidosis with the substitution of bicarbonate for chloride in intravenous fluids. It may also include the administration of ammonia scavengers such as sodium benzoate or sodium phenylbutyrate. Treatment with N-carbamyl-L-glutamate can rapidly normalise ammonia levels by stimulating the first step of the urea cycle.
Our understanding of optimal treatment strategies for organic acidaemias is still evolving. Timely diagnosis is essential and best achieved by the early identification of hyperammonaemia and metabolic acidosis. Correcting metabolic imbalance and hyperammonaemia are critical to prevent brain damage in affected patients.