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

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.

Comparison of electromagnetic guided imagery to standard confirmatory methods for ascertaining nasogastric tube placement in children

PURPOSE

Evaluate the accuracy of an electromagnetic device (EMD) guided nasogastric tube (NGT) placement compared with standard confirmation methods. A secondary aim was to determine if EMD guided NGT placement would avert potential pulmonary misplacements of the tube.

DESIGN AND METHODS

Pediatric Intensive Care Unit (PICU) patients were enrolled if they had an NGT order during the study period of April 2014 through December 2016. Patients were included if they were one through 18 years of age. An EMD trained nurse inserted the NGT using EMD guidance. An insertion questionnaire, confirming if the nurse determined the NGT to be gastric per EMD, was completed immediately after NGT placement and before confirmation via either pH testing or radiographic imaging.

RESULTS

Forty-five patients were enrolled in the study. Nurses reported, based on EMD, that 86.7% (n = 39) of placements were gastric. Overall agreement between EMD guided tube placement and pH testing was 58% (n = 26). The marginal distribution was significantly different between the two methods (p = .0029). When compared to radiographic confirmation, sensitivity of the pH method was 32% (95% confidence interval [CI]: 17%-51%) compared with 85% (95% CI 69%-95%) for the EMD method.

CONCLUSIONS

EMD guidance was superior to pH testing when compared with radiographic confirmation of nasogastric tube placement in children.

PRACTICE IMPLICATIONS

EMD guided NGT placement is a potentially viable method for confirming nasogastric tube placement in children when done by appropriately trained clinicians. More research on EMD guided NGT placement in children is needed before any practice recommendation can be made.

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.