Can We Ignore Laryngeal Penetration?

A recent retrospective study (DR Duncan et al. JPGN 2019; 68: 218-24) makes it clear that laryngeal penetration is an important finding when identified on a swallow study. The authors reviewed charts from 137 subjects (mean age 9 months) who had laryngeal penetration but not aspiration with a video swallow study (VSS).

Key findings:

  • 40% of patients with laryngeal penetration receiving thickening of feeds as treatment, 15% had a change in flow rate.  60% were maintained on thin liquids.
  • Thickening feeds was significantly associated with improvement in symptoms with OR 41.8.  91% of subjects with thickening had symptom improvement compared to 19% among group with no feeding intervention.
  • Subjects receiving a feeding intervention (thickening or change in flow rate) had decreased total  and pulmonary hospitalizations.  In contrast, in patients who did not have a feeding intervention, no significant decrease in hospitalization was noted. These data are tabulated in Table 3.  It is worth noting that those who had feeding intervention had higher risk of admission prior to feeding intervention, 0.69 compared to 0.53 for non-intervention group. Afterwards, the feeding intervention group  risk was  0.40 compared to 0.45 for the non-intervention group.
  • On followup VSS, 26% had evidence of aspiration.

One key point is that those with deep penetration were much more likely to have their feeds thickened/adjusted.

My take: This study makes it clear that all symptomatic children with laryngeal penetration should have adjustment in their feedings, most often thickening of their feeds.   These interventions appear to lower hospitalizations and are needed because in many cases the swallow dysfunction does not resolve or worsens.

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Clinical Evaluation Not Sensitive for Aspiration

A recent retrospective study (in press): abstract link: Presenting Signs and Symptoms do not Predict Aspiration Risk in Children DR Duncan et al. J Pediatr 2018;  https://doi.org/10.1016/j.jpeds.2018.05.030

From Boston Children’s Hospital Notes (9/12/18):

  • More than 80 percent of aspiration was silent
  • Rosen, Duncan and colleagues also found that observed feedings, even by very skilled clinicians, are not sensitive enough to diagnose aspiration in children because of the high rates of silent aspiration. Based on statistical analyses, the degree of agreement between observed feeding and the VFSS was poor for the diagnosis of aspiration.
  • Almost a third of the patients experienced symptoms during or after meals, which may help explain why physicians frequently misdiagnose oropharyngeal dysphagia with aspiration as gastroesophageal reflux disease (GERD).

Full abstract:

Objectives

To determine if any presenting symptoms are associated with aspiration risk, and to evaluate the reliability of clinical feeding evaluation (CFE) in diagnosing aspiration compared with videofluoroscopic swallow study (VFSS).

Study design

We retrospectively reviewed records of children under 2 years of age who had evaluation for oropharyngeal dysphagia by CFE and VFSS at Boston Children’s Hospital and compared presenting symptoms, symptom timing, and CFE and VFSS results. We investigated the relationship between symptom presence and aspiration using the Fisher exact test and stepwise logistic regression with adjustment for comorbidities. CFE and VFSS results were compared using the McNemar test. Intervals from CFE to VFSS were compared using the Student ttest.

Results

A total of 412 subjects with mean (±SD) age 8.9 ± 6.9 months were evaluated. No symptom, including timing relative to meals, predicted aspiration on VFSS. This lack of association between symptoms and VFSS results persisted even in the adjusted multivariate model. The sensitivity of CFE for predicting aspiration by VFSS was 44%. Patients with a reassuring CFE waited 28.2 ± 8.5 days longer for confirmatory VFSS compared with those with a concerning CFE (P < .05).

Conclusions

Presenting symptoms are varied in patients with aspiration and cannot be relied upon to determine which patients have aspiration on VFSS. The CFE does not have the sensitivity to consistently diagnose aspiration so a VFSS should be performed in persistently symptomatic patients.

My take: This study provides more data indicating that clinical evaluations are not reliable in children less than 2 years of age to exclude formal swallow study evaluations and that some symptoms attributed to reflux are in fact due to aspiration.

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