VIRAL CROUP

Def.: heterogeneous group of mainly acute and infectious upper airway obstruction processes that are characterized by a barking like or brassy cough and may be associated with hoarseness, inspiratory stridor, and respiratory distress.

It is acute laryngotracheitis, Laryngotracheobronchitis!

Incidence:

·       The most common form of acute upper respiratory obstruction.

·       Affect about 15% of children.

·       It is most common between 6 m΄ and 6 years of age, with a peak prevalence in the 2^nd year of life, rare over the age of 10 years.

·       Boys > girls.

·       Season; a peak in autumn and winter is associated with parainfluenza virus but can occur throughout the year.

·       Croup is uncommon < 6 months of life.

·       Rarely lasts more than 10 to 14 days.

·       Approximately 15% of patients have a strong FHx of croup.

ETIOLOGY:

·       Parainfluenza viruses type 1 , 2 and 3 (account for ≈75% of cases(

·       Other viruses including RSV, adenovirus, influenza, and measles: Influenza has been associated with more severe cases.

Pathogenesis:

·       After inhalation of the virus, the cells of the local respiratory epithelium become infected.

·       There is marked edema of the lamina propria, submucosa, and adventitia accompanied by cellular infiltration with histiocytes, lymphocytes, plasma cells, and PNLs.

·       The infant’s glottis and subglottic region are normally narrow, and a small ↓ in diameter → large ↑ in airway resistance & ↓ in airflow.

High anion gap metabolic acidosis mnemonic.

High anion gap metabolic acidosis mnemonic.

(RUSH Kill ME)

Renal tubular acidosis (distal), Rhabdomyolysis (massive)

Uremia

Salicylate ingestion

Hypovolemia, Heart failure

 

Ketoacidosis (diabetic, starvation)

Inborn error of metabolism, Iron, Isoniazid ingestion

Lactic acidosis

Late metabolic acidosis of prematurity

 

Mitochondrial diseases, Methanol ingestion

Ethanol, Ethylene glycol ingestion

Prevention and management of refeeding syndrome.

Prevention and management of refeeding syndrome

To ensure adequate prevention, the NICE guidelines recommend a thorough nutritional assessment before refeeding is started.

Recent weight change over time, nutrition, alcohol intake, and social and psychological problems should all be ascertained.

Plasma electrolytes (especially phosphate, sodium, potassium, and magnesium) and glucose should be measured at baseline before feeding and any deficiencies corrected during feeding with close monitoring.

For decades, the key to preventing the syndrome was believed to be lower-calorie refeeding with cautious advancement. preventing the syndrome

The NICE guidelines recommend that refeeding is started at no more than 50% of energy requirements for the 1^st 2 days in " patients who have eaten little or nothing for more than 5 days.” The rate can then be increased if no refeeding problems are detected on clinical and biochemical monitoring.

The prescription for people at high risk of developing refeeding problems should consider:

·      starting nutrition support at a maximum of 10 kcal/kg/day, increasing levels slowly to meet or exceed full needs by 4 to 7 days.

·    using only 5 kcal/kg/day in extreme cases (for example, BMI less than 14 kg/m2 or negligible intake for more than 15 days) and monitoring cardiac rhythm continually in these people and any others who already have or develop any cardiac arrythmias.

·     restoring circulatory volume and monitoring fluid balance and overall clinical status closely.

·     providing immediately before and during the first 10 days of feeding: oral thiamin 200 to 300 mg daily, vitamin B co strong 1 or 2 tablets, 3 times a day (or full dose daily intravenous vitamin B preparation, if necessary) and a balanced multivitamin or trace element supplement once daily.

·   providing oral, enteral or intravenous Maintenance requirement of potassium (likely requirement 2 to 4 mmol/kg/day), phosphate (likely requirement 0.3 to 0.6 mmol/kg/day) and magnesium (likely requirement 0.2 mmol/kg/day intravenous, 0.4 mmol/kg/day oral) unless pre-feeding plasma levels are high; pre-feeding correction of low plasma levels is unnecessary.

The following guidance is a suggestion for possible electrolyte repletion for refeeding syndrome in adolescents with eating disorders:

Clinical Signs and Symptoms of Refeeding Syndrome.

Clinical Signs and Symptoms of Refeeding Syndrome

References  

1. Fuentebella, J., & Kerner, J. A. (2009). Refeeding Syndrome. Pediatric Clinics of North America, 56(5), 1201–1210. doi:10.1016/j.pcl.2009.06.006.
2. Jason M. Nagata and Andrea K. Garber, refeeding syndrome, Nelson 22th ed 2024, Vol 1, ch 63.