Update on Effectiveness of an Electromagnetic Feeding Tube-Placement Device in Detecting Respiratory Placements

Feeding tube safety: National guidance ignores the 'elephant in the room'

BackgroundNational guidance attempts to prevent tubes remaining undetected and being used when misplaced in the respiratory tract. The 'elephant in the room' is that this guidance detects misplacement too late to prevent most pneumothoraces and pneumonias.ObjectiveReview risks of undetected and detected respiratory or oesophageal tube misplacements and how 'in-procedure' methods of determining tube position might reduce them.MethodsTube misplacement risk was compared for different methods of checking tube position. Data were obtained from UK NHS England (NHSE), a literature search between 1986 and 12/07/2024 using CINAHL, Embase, Medline and Emcare and from a local database.ResultsPost-procedure pH or X-ray checks on tube position have failed to prevent a rising incidence of undetected respiratory misplacements (NEVER events) (0.013%). Worse, current checks cannot prevent the 0.52% of placements that lead to in-procedure pneumothorax, constituting 97% of lung complications. In addition, pH may fail to prevent aspiration risk from oesophageal misplacement. Conversely, pneumothorax-risk would be reduced to 0.021% by using a supplementary mid-procedure CO2 check or to 0.005% with expert guided tube placement (both p < 0.0001). Guided tube placement can additionally pre-empt oesophageal-related complications, but its safety is expert-dependent, with higher rates of undetected misplacement and pneumothorax in low-use Cortrak centres (0.10%) than expert centres (0%, p < 0.009).ConclusionThe high health burden from feeding tube-related complications could be almost eliminated if regulatory authorities recommended a mid-procedure CO2 check for respiratory placement or expert guided tube placement, alongside mandates for the necessary training.

Assessing the Reproducibility of Research Based on the Food and Drug Administration Manufacturer and User Facility Device Experience Data

OBJECTIVE

This article aims to assess the reproducibility of Manufacturer and User Facility Device Experience (MAUDE) data-driven studies by analyzing the data queries used in their research processes.

METHODS

Studies using MAUDE data were sourced from PubMed by searching for "MAUDE" or "Manufacturer and User Facility Device Experience" in titles or abstracts. We manually chose articles with executable queries. The reproducibility of each query was assessed by replicating it in the MAUDE Application Programming Interface. The reproducibility of a query is determined by a reproducibility coefficient that ranges from 0.95 to 1.05. This coefficient is calculated by comparing the number of medical device reports (MDRs) returned by the reproduced queries to the number of reported MDRs in the original studies. We also computed the reproducibility ratio, which is the fraction of reproducible queries in subgroups divided by the query complexity, the device category, and the presence of a data processing flow.

RESULTS

As of August 8, 2022, we identified 523 articles from which 336 contained queries, and 60 of these were executable. Among these, 14 queries were reproducible. Queries using a single field like product code, product class, or brand name showed higher reproducibility (50%, 33.3%, 31.3%) compared with other fields (8.3%, P = 0.037). Single-category device queries exhibited a higher reproducibility ratio than multicategory ones, but without statistical significance (27.1% versus 8.3%, P = 0.321). Studies including a data processing flow had a higher reproducibility ratio than those without, although this difference was not statistically significant (42.9% versus 17.4%, P = 0.107).

CONCLUSIONS

Our findings indicate that the reproducibility of queries in MAUDE data-driven studies is limited. Enhancing this requires the development of more effective MAUDE data query strategies and improved application programming interfaces.

Validation of image interpretation for direct vision-guided feeding tube placement

BACKGROUND

Unguided (blind) tube placement commonly results in lung (1.6%) and oesophageal (5%) misplacement, which can lead to pneumothorax, aspiration pneumonia, death, feeding delays, and increased cost. Use of real-time direct vision may reduce risk. We validated the accuracy of a guide to train new operators in the use of direct vision-guided tube placement.

METHODS

Using direct vision, operators matched anatomy viewed to anatomical markers in a preliminary operator guide. We examined how accurately the guide predicted tube position, specifically whether respiratory and gastrointestinal placement could be differentiated.

RESULTS

A total of 100 patients each had one tube placement. Placement was aborted in 6% because of inability to enter or move beyond the oesophagus. In 15 of 20 placements in which the glottic opening was identified, the tube was maneuvered to avoid entry into the respiratory tract. Of 96 tubes that reached the oesophagus, 17 had entered the trachea; all were withdrawn pre-carina. One or more specific characteristics identified each organ, differentiating the trachea-oesophagus (P < 0.0001), oesophagus-stomach, and stomach-intestine in 100%. End-of-procedure tube position was ascertained by pH ≤4.0 (gastric) of aspirated fluid and/or x-ray (gastric or intestinal). In patients with a trauma risk (13%), it was avoided by identification that the tube remained within the nasal, oesophageal, or gastric lumen.

CONCLUSION

Operators successfully matched anatomy seen by direct vision to images and descriptions of anatomy in the "operator guide." This validated that the operator guide accurately facilitates interpretation of tube position and enabled avoidance of lung trauma and oesophageal misplacement.

Safety of blind versus guided feeding tube placement: Misplacement and pneumothorax risk

Most intensive care unit patients require a feeding tube, but misplacement risk is high due to the presence of artificial airways and because unconsciousness reduces clinical warnings. Predominantly, tubes are placed 'blindly', where position is not known throughout placement. The result is that 1.6% enter the lung, 0.5% cause pneumothorax and potentially 5% are left in the oesophagus. Guided placement, by identifying tube position in real time, may prevent these problems, but undetected misplacements still occur. We review the safety of guided methods of confirming tube position, including rates of pneumothorax, in the context of current unguided methods. During blind tube placement, tube position can only be tracked intermittently. Excepting X-ray and ultra-sound, most methods of checking position are simple. Conversely, guided tube placement can track tube position from the nose to small intestine (IRIS®), or oesophagus to jejunum (Cortrak™, ENvue®). However, this requires expertise. Overall, guided placement is associated with lower rates of pneumothorax. Unfortunately, for Cortrak, low-use centres have higher rates of undetected misplacement compared with blind placement whereas Cortrak use in high-use centres had lower risk compared with blind placement and low use centres. Because guided placement requires high-level expertise manufacturer training packages have been developed but currently appear insufficient. Specifically, Cortrak's package is less accurate in determining tube position compared to the 'gastrointestinal flexure' system. Validation of an evidence-based guide for IRIS placement is underway. Recommendations are made regarding the training of new operators, including minimum numbers of placements required to achieve expertise.

Intrapulmonary Feeding Tube Placements While Using an Electromagnetic Placement Device: A Review (2019-2021)

BACKGROUND

Intrapulmonary placements of feeding tubes inserted with use of an electromagnetic placement device (EMPD) continue to occur.

OBJECTIVE

To describe circumstances and outcomes associated with intrapulmonary feeding tube placements during use of an EMPD.

METHODS

A retrospective review of reports to the US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database of intrapulmonary feeding tube placements during use of an EMPD from 2019 through 2021. Complications, outcomes, operator training, interference from anatomical variations and medical devices, and the use and accuracy of radiographs in identifying pulmonary placements were recorded.

RESULTS

Sixty-two cases of intrapulmonary tube placement were identified; 10 were associated with a fatal outcome. Pneumothorax occurred in 35 cases and feedings were delivered into the lung in 11 cases. User error was cited in 6 cases and was implicit in most others. Little information was provided about operator training. Four intrapulmonary placements were associated with anatomical variations and 1 with a left ventricular assist device. Radiographic follow-up was described in 28 cases and correctly identified 23 of the intrapulmonary placements.

CONCLUSIONS

User error was a significant factor, which highlights the need for empirical data to clarify the amount of training needed to safely credential EMPD operators. Clearer information is needed about anatomical variations that may contraindicate use of an EMPD, as well as medical devices that may interfere with an EMPD. Use of follow-up radiographs, interpreted by qualified personnel, is supported to increase the probability of identifying intrapulmonary tube placements.

Integrated real-time imaging system, 'IRIS', Kangaroo feeding tube: a guide to placement and image interpretation

Background

Lung complications occur in 0.5% of the millions of blind tube placements. This represents a major health burden. Use of a Kangaroo feeding tubes with an ‘integrated real-time imaging system’ (‘IRIS’ tube) may pre-empt such complications. We aimed to produce a preliminary operator guide to IRIS tube placement and interpretation of position.

Methods

In a single centre, IRIS tubes were prospectively placed in intensive care unit patients. Characteristics of tube placement and visualised anatomy were recorded in each organ to produce a guide.

Results

Of 45 patients having one tube placement, 3 were aborted due to refusal (n=1) or inability to enter the oesophagus (n=2). Of 43 tubes placed beyond 30 cm, 12 (28%) initially entered the respiratory tract but all were withdrawn before reaching the main carina. We identified anatomical markers for the nasal or oral cavity (97.8%), respiratory tract (100%), oesophagus (97.6%), stomach (100%) and intestine (100%). Organ differentiation was possible in 100%: trachea-oesophagus, oesophagus-stomach and stomach-intestine. Gastric tube position was confirmed by aspiration of fluid with a pH <4.0 and/ or X-ray. Trauma was avoided in 13.6% by identifying that the tube remained in the nasal lumen in the presence of a base of skull fracture (n=3) and in the stomach in the presence of recently bleeding polyps or mucosa (n=3). A systematic guide was produced from records of tube placement and interpretation of anatomical images.

Conclusion

By permitting real-time confirmation of tube position, direct vision may reduce risk of lung complications. The preliminary operator guide requires validation in larger studies.

Cortrak feeding tube placement: accuracy of the 'GI flexure system' versus manufacturer guidance

Electromagnetic (EM) guided enteral tube placement may reduce lung misplacement to almost zero in expert centres, but more than 60 undetected misplacements had occurred by 2016 resulting in major morbidity or death.

AIM

Determine the accuracy of manufacturer guidance in trace interpretation against what is referred to as the 'GI flexure system'.

METHODS

The authors prospectively observed the accuracy of the 'GI flexure system' of trace interpretation against manufacturer guidance in primary nasointestinal (NI) tube placements.

FINDINGS

Contrary to manufacturer guidance, 33% of traces deviated >5 cm from the sagittal midline and 26.5% were oesophageal when entering the lower left quadrant, incorrectly indicating lung and gastric placement, respectively. Conversely, the GI flexure system identified ≥99.4% of GI traces when they reached the gastric body flexure; 100% at the superior duodenal flexure. All lung misplacements were identified by the absence of GI flexures.

CONCLUSION

Current manufacturer guidance should be updated to the GI flexure system of interpretation.

Electromagnetic Versus Blind Guidance of a Postpyloric Feeding Tube in Critically Ill Children

BACKGROUND AND OBJECTIVES

Postpyloric feeding tube placement is a time-consuming procedure associated with multiple attempts and radiation exposure. Our objective with this study is to compare the time, attempts, and radiation exposure using the electromagnetic versus blind method to place a postpyloric feeding tube in critically ill children. Our hypothesis is that using electromagnetic guidance decreases the procedure time, number of x-rays, and number of attempts, compared to the blind method.

METHODS

Eleven pediatric nurses participated in a randomized controlled intention-to-treat study at an academic pediatric medical, surgical, and congenital cardiac ICU. University of Texas Health Epidemiology and Biostatistics generated a randomization sequence with sealed envelopes. A standard (2-sided) F-test of association between the electromagnetic and blind method yielded 40 subjects with 86% power. Data were analyzed with Fisher's exact test for categorical variables and the Wilcoxon rank test for continuous variables, with data documented as median (interquartile range [IQR]).

RESULTS

We randomly assigned 52 patients to either the electromagnetic (n = 28) or blind method (n = 24). The number of attempts and radiographs was at a median of 2 (IQR: 1-2.25) using the blind method, compared to the electromagnetic method at a median of 1 (IQR: 1.0-1.0; P = .001). Successful guidance was 96.4% with the electromagnetic method, compared to only 66.7% with the blind technique (P = .008). The total time required was 2.5 minutes (IQR: 2.0-7.25) with the electromagnetic method, compared to 19 minutes (IQR: 9.25-27.0) for the blind method (P = .001).

CONCLUSIONS

Electromagnetic guidance is a superior, faster, and overall safer method to place a postpyloric feeding tube in critically ill children.

Cortrak feeding tube placement: interpretation agreement of the ‘GI flexure’ system versus X-ray

Background:

Blind (unguided) feeding tube placement results in 0.5% of patients suffering major complications mainly due to lung misplacement detected prior to feeding. Electromagnet-guided (Cortrak) tube placement could pre-empt such complications but undetected misplacements still occur due to incorrect trace interpretation. By identifying gastrointestinal (GI) flexures from the trace, ‘the GI flexure system’, it has been proposed that tube position can be interpreted.

Aims:

To audit agreement between standards of interpreting tube position: the Cortrak ‘GI flexure’ system versus X-ray.

Methods:

In 185 primary nasointestinal tube placements tube position determined by Cortrak trace interpretation (GI flexure) was retrospectively compared with radiological position in a blinded study.

Findings:

Radiological and Cortrak interpretation agreed in 92.2–98.3% of placements at different GI flexures. Discrepancy mainly occurred because some radiological images were unclear or did not cover all anatomical points.

Conclusion:

The GI flexure method of Cortrak interpretation appears safe but would necessitate prospective radiological investigation to definitively test equivalence.

Pneumothoraces Prevented With Use of Electromagnetic Device to Place Feeding Tubes

BACKGROUND

A US Food and Drug Administration safety letter warned about the risk for pneumothoraces during feeding tube insertion despite the use of electromagnetic placement devices that provide real-time visualization of feeding tube position.

OBJECTIVES

To systematically assess pulmonary placement and pneumothoraces in CORTRAK-assisted feeding tube insertions.

METHODS

CINAHL, MEDLINE, and Cochrane databases were searched for studies of CORTRAK-assisted feeding tube insertion. Thirty-two studies documenting pulmonary placement and/or complications of feeding tube insertion were found.

RESULTS

Operators recognized pulmonary placement on insertion tracings during 202 CORTRAK-assisted feeding tube insertion procedures, resulting in the immediate withdrawal of 199 feeding tubes. One pneumothorax was identified later by radiography. Seven pulmonary placements were not recognized by CORTRAK operators at the time of feeding tube insertion, resulting in 2 pneumothoraces. The incidence of pneumothorax for CORTRAK-assisted feeding tube insertions was 0.02% (3 of 17039). Of the feeding tubes inserted into the pulmonary system - either found during or after the procedure -1.4% (3 of 209) resulted in pneumothoraces (as opposed to the 19% to 28% incidence of pneumothorax for blind feeding tube insertions. Operators recognizing pulmonary placement on CORTRAK insertion tracings may have prevented 97% (202 of 209) of feeding tubes from being inserted farther into the respiratory tract.

CONCLUSIONS

Feeding tube insertion with an electromagnetic placement device is advantageous over blind feeding tube insertion because the operator can recognize pulmonary placement early and withdraw the feeding tube, thus decreasing the risk of pulmonary complications.

Undetected Cortrak tube misplacements in the United Kingdom 2010-17: An audit of trace interpretation

OBJECTIVES

Determine why Cortrak-guided, undetected tube misplacement may occur in relation to the system of trace interpretation used.

METHODOLOGY

From 2010 to 2017 we obtained seven of the eight Cortrak traces from the United Kingdom where misplacement was undetected and the patient received feed. Seven suffered serious harm. Each misplacement was interpreted by three systems: screen position, manufacturer guidance and gastrointestinal (GI) flexures.

SETTING

National and local records.

MAIN OUTCOME MEASURES

Ability to identify misplacement.

RESULTS

Traces that were later identified as misplacements, could not be differentiated from GI position when they wholly or partially: a) overlapped with the GI screen area plotted from historical records (57-71%) or b) met both manufacturer guidance criteria or were confused with receiver misplacement or unusual anatomy and reached the lower left quadrant (14-71%). Conversely, all lung misplacements were identified as unsafe using the GI flexure system. All three systems failed to detect the intra-peritoneal trace. Traces were inconsistently stored by healthcare centres.

CONCLUSION

Trace file storage should be mandated by and accessible to relevant health authorisation bodies to improve safety research. Screen position alone and manufacturer guidance fail to consistently differentiate the shape of safe from unsafe traces. GI flexure interpretation appears safer but requires testing in larger studies.

CORTRAK Superuser Competency Assessment and Training Recommendations

BACKGROUND

Blind insertion of feeding tubes remains unsafe. Electromagnetic placement devices such as the CORTRAK Enteral Access System allow operators to interpret placement of feeding tubes in real time. However, pneumothoraces have been reported and inadequate user expertise is a concern.

OBJECTIVE

To explore factors influencing competency of CORTRAK-assisted feeding tube insertion.

METHODS

A prospective, observational pilot study was conducted. Data collection included demographics, self-confidence, clinical judgment regarding CORTRAK-assisted feeding tube insertion, and general self-efficacy. CORTRAK-assisted feeding tube insertions were performed with the Anatomical Box and CORMAN task trainers.

RESULTS

Twenty nurses who had inserted a mean of 53 CORTRAK feeding tubes participated. Participants inserted a mean of 2 CORTRAK feeding tubes weekly; each had inserted a feeding tube in the past 7 days. All superusers were competent; 1 required remediation for improper receiver unit placement. Mean (SD) scores were 35 (3.68) on a 40-point scale for self-efficacy, 4.6 (0.68) on a 5-point scale for self-reported feeding tube insertion confidence, and 4.85 (0.49) on a 5-point scale for demonstrated confidence. Participants estimated that 8 CORTRAK-assisted insertions were needed before they felt competent as super users. Confidence with the CORTRAK tracing was estimated to require 10 feeding tube insertions. Six participants continued to assess placement by auscultation, suggesting low confidence in their interpretation of the tracing.

CONCLUSIONS

At least 3 observations should be performed to assess initial competency; the number should be individualized to the operator. Interpretation of the insertion tracing is complex and requires multiple performance opportunities to gain competency and confidence for this high-risk skill.

Pediatric Nasogastric Tube Placement and Verification: Best Practice Recommendations From the NOVEL Project

The placement of a nasogastric tube (NGT) in a pediatric patient is a common practice that is generally perceived as a benign bedside procedure. There is potential risk for NGT misplacement with each insertion. A misplaced NGT compromises patient safety, increasing the risk for serious and even fatal complications. There is no standardized method for verification of the initial NGT placement or reverification assessment of NGT location prior to use. Measurement of the acidity or pH of the gastric aspirate is the most frequently used evidence-based method to verify NGT placement. The radiograph, when properly obtained and interpreted, is considered the gold standard to verify NGT location. However, the uncertainty regarding cumulative radiation exposure related to radiographs in pediatric patients is a concern. To minimize risk and improve patient safety, there is a need to identify best practice and to standardize care for initial and ongoing NGT location verification. This article provides consensus recommendations for best practice related to NGT location verification in pediatric patients. These consensus recommendations are not intended as absolute policy statements; instead, they are intended to supplement but not replace professional training and judgment. These consensus recommendations have been approved by the American Society for Parental and Enteral Nutrition (ASPEN) Board of Directors.

Cortrak tube placement part 2: guidance to avoid misplacement is inadequate

Electromagnetic (EM)-guided tube placement has been successfully used to pre-empt lung misplacement, but undetected misplacements continue to occur. The authors conducted an audit to investigate whether official Cortrak or local guidance enabled differentiation of gastrointestinal (GI) from lung traces. X-ray, pH or an EM trace beyond the gastric body were used to independently confirm gastric position. The authors undertook 596 nasointestinal (NI) tube placements, of which 361 were primary GI placements and 41 lung misplacements. Official guidance that in GI traces a midline deviation is absent cannot differentiate GI from lung traces because deviation is common in both. However, when comparing a trace in the same patient, midline deviation during lung misplacement always occurred >18 cm above the horizontal line compared with only 33% of the subsequent GI deviation (p<0.0001). Official guidance could lead to aborted GI placements or undetected lung placements. EM-guided placement must have an expert-led understanding of the 3D trace pattern, artefact correction and appraised practical experience differentiating GI from lung placement. The authors invite Halyard Health to update guidance in view of these findings.