[Testing nasogastric tube placement: evaluation of three different methods in intensive care unit]

Evaluation of three methods (aspiration of gastric fluid, pH measurement of gastric fluid, and insufflation of air) in order to determine the right position of the nasogastric (NG) tube.

Prospective, observational study in an intensive care unit.

All patients requiring a NG tube were included. Since the NG tube was inserted three tests were successively performed: aspiration of gastric fluid, pH measurement of the gastric fluid, and auscultation over the epigastrium of air injected through the NG tube. The feasibility and the results obtained for each test were noted and compared to chest X-ray, considered as the reference. Chest X-ray classified the complications as major or minor.

A total of 419 NG tube (202 decompressive NG tube and 217 gastric feeding tube) were analysed in 280 patients. Malpositions of the NG tube were observed in 10% (majors, n=11 and minors, n=31). Aspiration of gastric fluid and pH measurement were not sensible (77% and 49%, respectively) and not specific (38% and 74%, respectively). Insufflation of air was sensible (96%) but not specific (17%). The combination of the three methods did not improve the sensibility and specificity. Two complications were only detected by chest X-ray (one insertion in the intrapleural space, and one pneumothorax).

None of the test evaluated, alone or associated, was sufficient to avoid chest X-ray. Moreover the occurrence of two potential and serious complications only detected by chest X-ray increase this assertion.