Colorimetric capnography, a new procedure to ensure
correct feeding tube placement in the intensive care unit:
An evaluation of a local protocol☆
Arnaud Galbois MDa,b,⁎, Paola Vitry RNa,
Hafid Ait-Oufella MD, PhDa,b, Jean-Luc Baudel MDa,b,
Bertrand Guidet MDa,b,c, Eric Maury MD, PhDa,b,c, Georges Offenstadt MDa,b,c
aService de Réanimation Médicale, Hôpital Saint-Antoine (AP-HP), 184 rue du faubourg Saint-Antoine, 75571,
Paris Cedex 12, France
bUniversité Pierre et Marie Curie (Paris VI), France
cINSERM, UMR S-707, 75012, Paris, France
Intensive Care Unit;
Purpose: Radiography is the criterion standard method to ensure correct placement of a feeding tube.
Recently, excellent results were reported using a combination of colorimetric capnography and
epigastric auscultation, but the impact of this technique has not been studied to date. Objectives were to
assess whether our local procedure, using colorimetric capnography to ensure proper feeding tube
placement, improves the patient's care, satisfies nurses, and decreases costs compared with the standard
procedure requiring systematic radiography.
Material and Methods: Weperformedamonocentricprospectiveobservationalstudyinamedicalintensive
care unit over a 4-month period. Feeding tube placement was assessed by colorimetric capnography and
epigastric auscultation. Radiography was performed when epigastric auscultation was inconclusive.
Results: A total of 69 feeding tubes were placed in 44 patients. Radiography was required in 10.1% of the
cases. The new procedure decreased costs ($33.37 ± 13.96 vs $45.92, P b .0001) and was less time
consuming (11.6 ± 20.5 minutes vs 87.3 ± 45.2 minutes, P b .0001) than using systematic radiography. All
nurses reported confidence in the procedure, which improved the organization of their care.
Conclusions: The use of colorimetric capnography and epigastric auscultation to confirm feeding tube
placement improves nurse's organization of care, saves time, and decreases costs.
© 2011 Elsevier Inc. All rights reserved.
Enteral nutrition (EN) is the preferred method of
nutritional support for patients admitted to intensive care
units (ICUs). It should be started within the first days of
admission . Accidental placement of an enteral feeding
Abbreviations: ICU, intensive care unit; EN, enteral nutrition;
EFT, enteral feeding tube; CC, colorimetric capnography.
☆Institution where the work was performed: Service de Réanimation
Médicale, Hôpital Saint-Antoine (AP-HP), 184 rue du faubourg Saint-
Antoine, 75571, Paris Cedex 12, France.
⁎Corresponding author. Tel.: +33 9 52 78 30 51, +33 1 49 28 23 18
(work); fax: + 33 1 49 28 26 92.
E-mail address: email@example.com (A. Galbois).
0883-9441/$ – see front matter © 2011 Elsevier Inc. All rights reserved.
Journal of Critical Care (2011) 26, 411–414
tube (EFT) in the tracheobronchic airway can lead to
potentially lethal complications [2-4]. Tracheal intubation
of patients in ICU does not always prevent this
misplacement . Ensuring correct EFT insertion is
therefore of paramount importance for ICU patients.
Confirmation of EFT placement by epigastric auscultation
of air injected through the EFT is not a reliable test when
used alone [6-8]. Some groups have suggested testing the
pH of an aspirate obtained from the EFT to ensure proper
placement, but this test can be inconclusive in patients
with small-bore EFT or those on acid suppression .
Therefore, most guidelines recommend confirming EFT
placement by radiography before beginning EN [8-10].
However, a multicenter study recently performed in France
showed that x-rays are overprescribed and could be
reduced . We recently proposed a new method of
ensuring correct EFT placement by combining colorimetric
capnography (CC) and epigastric auscultation . This
procedure predicts the gastric position of the EFT with
perfect specificity, even if supplemental radiographs are
required in cases of inconclusive auscultation . The
potential requirement for radiography after CC could have
diminished potential interest in this procedure because it
requires more time and increases the cost of the procedure.
This procedure is now recommended in our ICU. We
conducted this study to assess whether this procedure
improves the patient's care, satisfies nurses, and decreases
costs in “real-life.”
2. Material and methods
This was a monocentric prospective observational study
conducted from May to August 2009 in a 14-bed medical
ICU in a tertiary teaching hospital. All cases involving EFT
insertion were included in the study.
2.2. Confirmation of EFT placement using CC
The CC device used (Easycap II; Nellcor-Puritan Bennet,
Inc, distributed by Tyco, Plaisir, France) displays different
colors according to ranges of CO2concentration (purple:
CO2b4 mm Hg; brown: CO2between 4 and 15 mm Hg;
yellow: CO2 N15 mm Hg). This CC device has been
elaborated to ensure tracheal tube placement after intubation,
and it is not fitted for a connection to an EFT. We attached
the CC device to the EFT (CAIR LGL, Civrieux d'Azergue,
Rhône, France) via the tip of an endotracheal tube (Portex
Tracheal Tube). Methodsfor using the CC were derived from
the initial study . Briefly, the EFT was inserted to a depth
of 30 cm from the nostril. The operator checked first that it
was not coiled in the pharynx, and then the guide wire was
pulled out. The nurse assessedthe permeability of the tubeby
insufflation and exsufflation of air with a 50-mL syringe. The
CC device was then connected to the EFT. The procedure
was continued as follows according to the color displayed by
the CC device. If the CC remained purple, the guide wire was
replaced, and the tube was inserted to a total depth of 50 cm.
If the CC color changed to yellow or brown, the EFT was
withdrawn and the procedure was started again. Following
CC detection, the operator performed epigastric auscultation
after air insufflation. If gurgling was heard, EN was started
immediately. If the auscultation was inconclusive, bedside
radiography was required to assess EFT placement.
We recorded the total number of radiographs required and
the time from the beginning of EFT placement to the onset of
EN. The final costs to confirm EFT placement were
calculated. Our institution bought each CC device and
endotracheal tube to the manufacturer for $22.78 and $5.95,
respectively. The cost of a bedside radiography evaluated by
our institution was $45.92. Thus, the cost to confirm EFT
placement was $28.73 with CC alone ($22.78 + $5.95) and
$74.65 when a bedside radiography was required ($22.78 +
$5.95 + $45.92). Each nurse was given an anonymous
questionnaire with 5 items to assess their opinion about
Results are expressed as n (%) or mean ± SD. The time
elapsed between the beginning of the procedure and the
onset of EN was compared with the time required for the
procedure involving systematic use of radiography
(recorded during the previous 4-month period) by the
Student t test.
3.1. Patients and EFT
During the 4 months of the study, 314 patients were
admitted to our ICU. A total of 69 EFTs were inserted in 44
Characteristics of patients in whom the EFTs
412A. Galbois et al.
patients (age, 66.5 ± 15.3 years; male, n = 26 [59.1%];
Simplified Acute Physiology Score II, 51 ± 16; length of stay
in ICU, 13.4 ± 15.8 days). The reasons for admission were as
follows: acute respiratory failure (n = 21, or 47.7%), coma
(n = 4, or 9.1%), and acute liver failure (n = 1, or 2.3%). The
mean (SD) number of EFTs per patient during their ICU stay
was 1.7 (0.9). Most of the EFTs was inserted in patients
receiving mechanical ventilation and/or with altered con-
sciousness (Table 1).
3.2. Radiography requirement to confirm
Methods used to confirm EFT placement are summarized
in Table 2. Combining CC and epigastric auscultation was
able to confirm the gastric position of EFT without requiring
radiography in 89.9% of cases.
3.3. Impact of CC to ensure correct EFT placement
Comparing this procedure with systematic use of
radiography to confirm EFT placement, CC and auscultation
decreased costs ($33.37 ± 13.96 vs $45.92 P b .0001) and
saved time (11.6 ± 20.5 minutes vs 87.3 ± 45.2 minutes, P b
.0001). All the 30 nurses working in the ICU answered the
questionnaire, and every one reported that CC was easy to
perform. Among them, 87% were confident in the
combination of CC and epigastric auscultation, 93% were
satisfied with this procedure, 93% thought that using CC
simplified the organization of patient's care, and none would
have preferred to give up this procedure in favor of
The main results of this study are that using CC to confirm
EFT placement improves the patient's care by saving time,
satisfies nurses, and decreases costs.
In the original study , a lack of CC color change when
the EFT was inserted to 30 cm (after ruling out that it was
coiled in the oropharynx) confirmed that the tube was in the
esophagus. The authors concluded that after the EFT was
inserted to 50 cm, epigastric auscultation was still needed to
ensure that the tube was not coiled in the esophagus. Thus, if
epigastric auscultation was inconclusive, radiography was
required. The potential requirement for radiography after CC
could have diminished potential interest in this procedure
because it requires more time and increases the cost of the
procedure. However, this study shows that in practice, use of
CC saves both time and money.
This procedure improves patient's care. Even though it is
advisable to begin EN shortly after admission to the ICU ,
saving 80 minutes will most likely not affect patient
outcomes. However, with CC, nurses can start EN
immediately after EFT insertion. The procedure is performed
in one time, avoiding the delay for the radiography. This
delay, sometimes very long, could be responsible of an
omission, especially when the workload is heavy. Nurses
expressed great satisfaction with CC and reported that this
saved time improved the organization of patient's care,
which is one of the clear advantages of this procedure.
Use of CC saved an average of $12 per EFT insertion,
resulting in savings of $2500 in 2009 in our ICU. This
economy is even above the cost of one EFT ($10.15).
Although examining the efficacy of this test was not a
goal of this study, all the 4 accidental EFT insertions in the
airway were diagnosed before starting EN, and all of them
were correctly inserted in the next attempt. The EFT and CC
device were the same models as in the initial study .
Because EFT permeability is essential for CC color
modification in the case of accidental EFT insertion in the
airway, if groups wish to use CC with other small-bore
EFT models, this technique should be validated for
The use of CC and epigastric auscultation, to confirm
feeding tube placement, improves nurse's organization of
care, saves time, and decreases costs.
 McClave SA, Martindale RG, Vanek VW, et al. Guidelines for the
provision and assessment of nutrition support therapy in the adult
critically ill patient: Society of Critical Care Medicine (SCCM) and
American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.).
JPEN J Parenter Enteral Nutr 2009;33(3):277-316.
 Torrington KG, Bowman MA. Fatal hydrothorax and empyema
complicating a malpositioned nasogastric tube. Chest 1981;79(2):
 Metheny NA, Aud MA, Ignatavicius DD. Detection of improperly
positioned feeding tubes. J Healthc Risk Manag 1998;18:37-48.
 Metheny N, Dettenmeier P, Hampton K, et al. Detection of inadvertent
respiratory placement of small-bore feeding tubes: a report of 10 cases.
Heart Lung 1990;19:631-8.
 Woodall BH, Winfield DF, Bisset III GS. Inadvertent tracheobronchial
placement of feeding tubes. Radiology 1987;165(3):727-9.
Methods used to confirm EFT placement
n (%) Cost per
Time required per
33.37 ± 13.96
5.5 ± 3.2
65.1 ± 30.7
11.6 ± 20.5
413 Colorimetric capnography ensure correct feeding tube placement
 Kunis K. Confirmation of nasogastric tube placement. Am J Crit Care
 Stroud M, Duncan H, Nightingale J. British Society of Gastroenter-
ology: guidelines for enteral feeding in adult hospital patients. Gut
 Metheny NA. Preventing respiratory complications of tube feedings:
evidence-based practice. Am J Crit Care 2006;15(4):360-9.
 Thuong M, Leteurtre S. Experts recommendations of the Société de
Réanimation de Langue Française. Enteral nutrition in critical care.
 Jolliet P, Pichard C, Biolo G, et al. Enteral nutrition in intensive care
patients: a practical approach. Working Group on Nutrition and
Metabolism, ESICM. European Society of Intensive Care Medicine.
Intensive Care Med 1998;24(8):848-59.
 Hejblum G, Chalumeau-Lemoine L, Ioos V, et al. Comparison of
routine and on-demand prescription of chest radiographs in mechan-
ically ventilated adults: a multicentre, cluster-randomised, two-period
crossover study. Lancet 2009;374(9702):1687-93.
 Meyer P, Henry M, Maury E, et al. Colorimetric capnography to
ensure correct nasogastric tube position. J Crit Care 2009;24(2):231-5.
414A. Galbois et al.