Multivariate analysis of factors associated with the successful prediction of initial blind placement of a nasointestinal tube in the stomach based on X-ray imaging: a retrospective, single-center study

Abstract

Background: Patients in the intensive care unit (ICU) are highly susceptible to malnutrition, and while enteral nutrition via nasogastric tube is the preferred method, there is a risk of inadvertent reflux and aspiration. Therefore, clinicians have turned to nasointestinal tubes (NET) for enteral nutrition as an alternative option. But the precise localization of NET presents an ongoing challenge. We proposed an innovative approach to provide a valuable reference for clinicians involved in NET placement.

Method: Data were obtained retrospectively from the medical records of adult patients with a high risk of aspiration or gastric feeding intolerance who had a NET placed in the ICU of Zhejiang Provincial People's Hospital between October 1, 2017, and October 1, 2023. The collected data were subjected to statistical analysis using SPSS and R software.

Result: There were 494 patients who met the inclusion and exclusion criteria. The first-pass success rate was 81.4% (n = 402). The success of a patient's initial NET placement was found to be associated with Angle SPC and Distance CP, as determined by univariate analysis (25.6 ± 16.7° vs. 41.9 ± 18.0°, P < 0.001; 40.0 ± 26.2 mm vs. 62.0 ± 31.8 mm, P < 0.001, respectively). By conducting a multivariate regression analysis, we identified a significant association between pyloric types and the success rate of placing NET (OR 29.559, 95%CI 14.084-62.038, P < 0.001).

Conclusion: Angle SPC, Distance CP, and the type of pylorus are independently associated with successful initial placement of NET. Besides, patients with the outside type of pylorus (OP-type) exhibit a higher rate of initial placement success.

Keywords: Blind placement; Intensive care unit; Nasointestinal tube; Post-pyloric feeding.

Fig. 1

Study flowchart. NET, nasointestinal tube

Fig. 2

Model draw of the stomach shape and the nasointestinal tube intragastric course under X-ray imaging. (A-B) Line (a) indicates the cardia level line. Line (b) indicates the pylorus superior margin level line. Line (c) indicates the lowest point of the edge of stomach level line. The lines (a), (b), and (c) are all perpendicular to the spinal line. The Angle cardia-pylorus-line a (Angle CPA) was defined as the angle formed by the line connecting the cardia to the upper edge of the pylorus and line (a). The Angle stomach-pylorus-line c (Angle SPC) was defined as the angle formed by the line connecting the lowest point of the lower edge of the stomach with the upper edge of the pylorus and line (c). Distance line c-pylorus (Distance CP) was defined as the distance from the superior margin of the pylorus to line (c)

Fig. 3

The type of pylorus. (A-B) OP-type, the outside type of pylorus. IP-type, the inside type of pylorus

Fig. 4

Receiver operating characteristic curve (ROC) of the Angle SPC and Distance CP in predicting the failure of nasointestinal tube placement. Angle SPC, Angle stomach-pylorus-line c; Distance CP, Distance line c-pylorus (the definitions of both are shown in Fig. 2)

Fig. 5

Constructed nomogram and performance of the model for predicting NET success rate of placement. (A) Nomogram according to clinical indices for predicting NET success rate of placement. The nomogram is used by adding up points identified on the points scale for each variable. The points of the six predictors should be added to calculate the total points. The straight edge should be aligned to the “total points,” and the predicted value would be visible on the last line. (B) Calibration curve of nomogram in the training cohort. The x-axis is the predicted probability from the nomogram, and the y-axis is the actual probability. The dashed line represents performance of the ideal nomogram (predicted outcome perfectly corresponds with actual outcome). The dotted line represents the apparent accuracy of our nomogram without correction. The solid line represents bootstrap-corrected performance of our nomogram. CRRT, continuous renal replacement therapy, 1 means yes, 0 means no; The type of pylorus, 1 means OP-type, 0 means IP-type; Time 1, the time from nasointestinal tube placement to the start post-pyloric feeding; Angle SPC, Angle stomach-pylorus-line c; Distance CP, Distance line c-pylorus (the definitions of both are shown in Fig. 2)