pH and specific gravity of corrosive agents as indicators in caustic injuries

Video endoscopy, which remains the diagnostic gold standard after ingestion of a corrosive substance, is performed under general anesthesia in children, requires advanced technology, and is costly. Simple and accessible methods are therefore needed to determine the need for endoscopy. The aim of this study was to evaluate the role of the pH and specific gravity of ingested substance in determining endoscopy indications after corrosive ingestion.

This prospective study included pediatric patients who presented after ingesting a corrosive substance from June 2018 to June 2019. Relationships between the extent of damage detected by endoscopy and the patient's age, physical examination findings, and the pH and specific gravity of the causative substance were evaluated.

The degree of damage detected on endoscopy was significantly milder for corrosive substances with a pH between 2 and 12 (P = 0.003). In addition, pH values between 2 and 12 were significantly more common among patients without physical examination findings (P = 0.029). Specific gravity less than 1,005 was associated with mild injury detected by video-endoscopy (P = 0.011). Patients in whom severe injury was detected by endoscopy had marked findings on physical examination (P < 0.001). There was no significant relationship between physical examination findings and the specific gravity of the substance involved (P = 0.087).

The results of this study suggest that conservative treatment options can be used without performing endoscopy in patients who have no physical examination finding after corrosive ingestion and where the pH of the substances is between 2 and 12 and the specific gravity of the substances is less than 1,005.