PLoS ONE (Jan 2022)

Nasogastric tube in mechanical ventilated patients: ETCO2 and pH measuring to confirm correct placement. A pilot study

  • Samuele Ceruti,
  • Simone Dell’Era,
  • Francesco Ruggiero,
  • Giovanni Bona,
  • Andrea Glotta,
  • Maira Biggiogero,
  • Edoardo Tasciotti,
  • Christoph Kronenberg,
  • Gianluca Lollo,
  • Andrea Saporito

Journal volume & issue
Vol. 17, no. 6

Abstract

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Introduction Nasogastric tube (NGT) placement is a procedure commonly performed in mechanically ventilated (MV) patients. Chest X-Ray is the diagnostic gold-standard to confirm its correct placement, with the downsides of requiring MV patients’ mobilization and of intrinsic actinic risk. Other potential methods to confirm NGT placement have shown lower accuracy compared to chest X-ray; end-tidal CO2 (ETCO2) and pH analysis have already been singularly investigated as an alternative to the gold standard. Aim of this study was to determine threshold values in ETCO2 and pH measurement at which correct NGT positioning can be confirmed with the highest accuracy. Materials & methods This was a prospective, multicenter, observational trial; a continuous cohort of eligible patients was allocated with site into two arms. Patients underwent general anesthesia, orotracheal intubation and MV; in the first and second group we respectively assessed the difference between tracheal and esophageal ETCO2 and between esophageal and gastric pH values. Results From November 2020 to March 2021, 85 consecutive patients were enrolled: 40 in the ETCO2group and 45 in the pH group. The ETCO2 ROC analysis for predicting NGT tracheal misplacement demonstrated an optimal ETCO2 cutoff value of 25.5 mmHg, with both sensitivity and specificity reaching 1.0 (AUC 1.0, p Discussion In patients receiving MV, ETCO2 and pH measurements respectively identified incorrect and correct NGT placement, allowing the identification of threshold values potentially able to improve correct NGT positioning. Trial registration NCT03934515 (www.clinicaltrials.gov).