The paracetamol absorption test: a useful addition to the enteral nutrition algorithm?

Background: Enteral nutrition in critically ill patients given via the nasogastric route is often decreased or stopped because of large gastric residual volumes. Aim: To assess the effect of continuing enteral nutrition in patients with an elevated gastric residual volume but normal gastric emptying by the paracetamol absorption test.Methods: The paracetamol absorption test was performed on all patients receiving enteral nutrition via a nasogastric tube who had a residual volume (assessed every 8 hours) of >150 ml or more than twice the hourly infusion rate. Patients were then divided into 2 groups according to the result of the test: Group 1 (n=8), normal gastric emptying; and Group II (n=24), abnormal gastric emptying. Group I continued to receive enteral nutrition. In Group II feeding was interrupted in 18 patients and prokinetic agents administered, while a subgroup of six patients continued to receive enteral nutrition without prokinetic agents. All patients were followed for evidence of delayed gastric emptying and aspiration.Results: Residual volumes were similarly elevated in both groups (p=0.25). Enteral nutrition was continued in Group I with no adverse effects. Prokinetic agents allowed enteral nutrition to be resumed in 88% of the 18 Group II patients. Enteral nutrition in the subgroup had to be stopped because of persistently elevated residual volumes.Conclusion: The paracetamol absorption test may be normal in patients with relatively high gastric residual volumes. These patients may continue to receive enteral nutrition.