Successful Management of Chemical Pneumonitis Due to Accidental Aspiration of Polyethylene Glycol in a Child

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Polyethylene glycol (PEG) electrolyte solution is a widely used osmotic laxative in children due to its efficacy and safety profile. Common adverse effects of PEG include nausea due to unpleasant taste, abdominal pain, cramps, and bloating, though more serious complications like pancreatitis, anaphylaxis, angioedema, ventricular arrhythmias, and lipoid pneumonias have also been reported.¹ Accidental aspiration of PEG solution into the lungs has been reported to cause fatal chemical pneumonitis, acute pulmonary oedema, and acute respiratory distress syndrome (ARDS) in a few anecdotal cases.¹

A previously healthy 1.5-year-old boy weighing 10 kg (weight for age -0.90 z; normal >-2z), who was a known case of chronic habitual constipation on daily maintenance PEG liquid solution (15 ml hrs), being self-medicated by the mother through online reading without physician advice, presented to the paediatric emergency department with irritability and respiratory distress the following morning, 14 hours after unwitnessed intake of a night dose of said solution (Movicol® liquid, 25 ml/13.125 g) at home, directly from the bottle. The child subsequently had an episode of vomiting, followed by choking, turned cyanotic for a few seconds, and later developed recurrent bouts of cough and subcostal chest retractions, consistent with aspiration of gastric contents, which made the mother suspicious of an accidental ingestion. The volume of ingestion was retrospectively approximated to be around 50 ml (around 2.5 times the maximum daily recommended maintenance dose) from the remaining quantity of leftover solution in the bottle. On admission, the child was grunting, irritable, with nasal flaring and head bobbing. Respiratory rate was 80/min (n:<40/min), oxygen saturation was 82% (n:>94%) on room air, with generalised fine crepitations on bilateral chest auscultation. Arterial blood gas on 100% oxygen through a non-rebreathing mask showed hypoxemia (paO₂ 55 mm Hg, normal:>80), respiratory alkalosis (pH 7.46, normal: 7.35- 7.45), pCO2 33 mm Hg (normal: 35-45), with a P: F ratio of 55 (severe acute respiratory distress syndrome (ARDS); normal >300). Chest X-ray revealed patchy heterogeneous infiltrates in the bilateral lung fields [Figure 1], suggestive of chemical aspiration pneumonitis. He was initially started on levosalbutamol, inhaled corticosteroids, and adrenaline nebulisations to aid bronchodilation and improve oxygenation. The child was subsequently intubated in view of respiratory failure and managed according to ARDS ventilatory strategies. Bronchoalveolar lavage (BAL) was withheld in view of the increased time elapsed from ingestion to presentation, obviating any therapeutic benefit. Intravenous methylprednisolone (2 mg/kg) and clindamycin (15 mg/kg q8h) were administered to tackle inflammatory acute lung injury and as prophylactic anaerobic cover for aspiration pneumonia, respectively. Remarkably, within 48 hours, his oxygen requirement decreased, allowing successful extubation to room air. Four weeks later, repeat chest radiographs revealed clearing of lung infiltrates.

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Figure 1:

Chest X-ray of the index case depicting bilateral heterogenous lung infiltrates (solid black arrows).

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To the best of our knowledge, this is the lowest reported age of a case of accidental PEG aspiration, with most previous reports of aspiration documented in pre-pubertal children.^1-4 PEG aspiration is mostly seen in adults who require large volumes to the tune of 4 litres for bowel cleansing before colonoscopy, resulting in gastric spasm and regurgitation.⁵ Paediatric cases of aspiration are rare, and most cases describe iatrogenic aspiration episodes during the administration of PEG by nasogastric tube for faecal dis-impaction, but never during routine household use.^1-4 PEG, although neutral in the gut, can lead to significant intraluminal fluid shifts in lung tissue because of hyperosmolar properties after aspiration, causing pulmonary oedema.¹ Besides, PEG by itself can likely cause inflammation of pulmonary tissue after aspiration and subsequently a chemical pneumonitis. Although BAL used to be recommended as the treatment of choice in previous studies to remove non-absorbable PEG from airways, the permeability of PEG in the gastrointestinal tract and the pulmonary epithelium differs, and most of the PEG is absorbed quickly from the airways, leaving the role of BAL doubtful; hence, it was not planned for our case.^1,5 This is further substantiated by studies in rodent models, where only half of a solution of 3.4 kDa PEG (similar in size to PEG used in children) remained in the alveoli after 9-10 hours of instillation.^1,6

Thus, this case underscores the need for cautious and supervised administration of PEG solution in toddlers to avoid aspiration accidents. When well tolerated during nasogastric administration for faecal dis-impaction, the flow rate can be slowly titrated to a recommended volume of 20 to 30 ml/minute.⁵ Treatment decisions like BAL should not be extrapolated from generalisations about the absorption and permeability of PEG in the gastrointestinal tract.