September 2019 HSC Section 1 Congenital and Pediatric Problems

study of 300 children by Weir et al. In this study, 34% of patients demonstrated aspiration and 81% of these patients specifically displayed silent aspiration. 3 Clini- cians should be aware that the absence of cough with deglutition does not rule out aspiration. Modified barium swallow is a particularly useful tool to evaluate swallowing in children suspected to have dysphagia. This test enables clinicians to measure the duration of oral and pharyngeal processes; identify pooling of material in the vallecula, pyriform sinuses, or pharyngeal recesses; and establish the occurrence and timing of aspiration. It is particularly useful in visualiz- ing silent aspiration, which feeding histories and clinical observations cannot reliably identify. During the MBS, clinicians can test patients on different food textures to better characterize impairment. In our study, thick (34%) and thin (32%) fluids were most commonly aspi- rated (Table I). When the silent aspiration subgroup was analyzed separately, it was clear that most patients silently aspirated thin fluids (49%), whereas fewer patients silently aspirated solid foods (8%). Of note, not all patients were tested on all consistencies. Patients who had previously demonstrated aspiration on thick fluids may have only been tested on thickened fluids. In addition, young infants (who would not be expected to consume puree or solids) and patients with no clinical concerns with purees/solids may not have been tested on these consistencies. Of patients tested on thin and/or thick fluids, 30% to 35% demonstrated aspiration and, of those, approximately 88% demonstrated silent aspira- tion. Of patients tested on puree or solids, 1% to 5% demonstrated aspiration and, of those, approximately 80% to 85% demonstrated silent aspiration. Assuming that the false positive rate of MBS is low, these results support the notions that: 1) children commonly aspirate

TABLE III. Aspiration Consistency in Patients With Silent Aspiration (n 5 393).

Percent of Patients Demonstrating Silent Aspiration

Fluid Consistency

n

Thin fluids only

192

48.9%

Thickened fluids only

43

10.9%

Thin and thickened fluids

125

31.8%

Puree or solid foods

33

8.4%

(median 5

1.1 years, IQR 5

0.4–2.5 vs. 1.3 years,

IQR 5 0.016). This was the only statistically significant difference between the two groups. There were no significant differences in the prevalence of any diagnoses, including airway disorders (RR 5 1.05; 95% CI 0.98, 1.12; P 5 0.15), neurologic disease (RR 5 1.04; 95% CI 5 0.97, 1.10; P 5 0.28), syndrome (RR 5 1.02; 95% CI 0.94, 1.11; P 5 0.66), and congenital heart disease (RR 5 1.05; 95% CI 5 0.96, 1.14; P 5 0.29). DISCUSSION Silent aspiration in children is challenging to detect and diagnose due to its lack of outward manifestations. It is often difficult to distinguish between normal chil- dren, who are assumed not to aspirate, and those who aspirate without overt cough or other signals. One must be suspicious of small signs, such as feeding difficulties and choking, in order to identify this condition. In our heterogeneous patient cohort of 1,286 children who underwent MBS in 2015, 34% of patients demonstrated aspiration on at least one consistency. Among children who aspirated, the vast majority showed silent aspira- tion (89.3%). Similar findings were reported in a recent 0.7–4.3; P 5

TABLE IV. Univariate and Multivariate Analysis of Clinical Factors Associated With Silent Aspiration.

Unadjusted RR (95% CI)

Adjusted RR (95% CI)

P Value

P Value

Age < 1 year

1.37 (1.16, 1.61)

< 0.001

1.56 (1.32, 1.84)

< 0.001

Airway disorder Laryngeal cleft

1.43 (1.14, 1.79)

0.002

1.67 (1.35, 2.05)

< 0.001

Laryngomalacia

1.36 (1.09, 1.69)

0.006

1.26 (1.02, 1.55)

0.029

Unilateral VFP

1.72 (1.20, 2.45)

0.003

1.42 (1.01, 2.00)

0.044

Neurologic disease

Developmental delay

1.31 (1.11, 1.55)

0.002

1.32 (1.11, 1.57)

0.002

Hypotonia

1.31 (1.06, 1.62)

0.013

–

Epilepsy/seizures

1.44 (1.16, 1.79)

< 0.001

1.52 (1.21, 1.90)

< 0.001

Microcephaly/macrocephaly

1.11 (0.78, 1.57)

0.57

–

Cerebral palsy

1.32 (0.92, 1.88)

0.13

–

Syndrome

1.31 (1.06, 1.63)

0.014

1.37 (1.11, 1.69)

0.004

Congenital heart disease

1.67 (1.32, 2.10)

< 0.001

1.69 (1.33, 2.14)

< 0.001

Prematurity

1.16 (0.96, 1.42)

0.13

–

GERD

0.90 (0.76, 1.08)

0.28

–

Adjusted RR and 95% CI were based on the multivariable log-binomial regression model that includes age ( < 1 year), laryngeal cleft, laryngomalacia, unilateral vocal fold paralysis, developmental delay, epilepsy/seizures, syndrome, and congenital heart disease. CI 5 confidence interval; GERD 5 gastroesophageal reflux disease; RR 5 risk ratio; VFP 5 vocal fold paralysis.

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Velayutham et al.: Silent Aspiration in the Pediatric Population elayutha et l.: il t i i

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