Serum electrolytes and outcome in patients undergoing endoscopic gastrostomy

Background – Percutaneous endoscopic gastrostomy (PEG) is a gold standard for long term enteral feeding. Neurologic dysphagia and head/neck cancer are the most common indications for PEG as they can lead to protein-energy malnutrition and serum electrolyte abnormalities, with potential negative impact on metabolic balance. Refeeding syndrome may also be related with severe electrolyte changes in PEG-fed patients and contribute to poor prognosis. Objective – This study aims to evaluate the changes in serum concentrations of the main electrolytes and its possible association with the outcome. Methods – Retrospective study of patients followed in our Artificial Nutrition Clinic, submitted to PEG from 2010 to 2016, having head/neck cancer or neurologic dysphagia, who died under PEG feeding. Serum electrolytes (sodium, potassium, chlorine, magnesium, calcium and phosphorus) were evaluated immediately before the gastrostomy procedure. Survival after PEG until death was recorded in months. Results – We evaluated 101 patients, 59 with electrolyte alterations at the moment of the gastrostomy. Sodium was altered in 32 (31.7%), magnesium in 21 (20.8%), chlorine in 21 (20.8%), potassium in 14 (13.8%), calcium in 11 (10.9 %) and phosphorus in 11 (10.9%). The survival of patients with low sodium (<135 mmol/L) was significantly lower when compared to patients with normal/high values, 2.76 months vs 7.80 months, respectively (P=0.007). Conclusion – Changes in serum electrolytes of patients undergoing PEG were very common. More than half showed at least one abnormality, at the time of the procedure. The most frequent was hyponatremia, which was associated with significantly shorter survival, probably reflecting severe systemic metabolic distress.