429 - Association of reduction in Mean Platelet Volume(MPV) in patients with bronchiolitis with respiratory distress and need for oxygen support

Bronchiolitis is a common lower respiratory tract infection among children in the United States and is the leading cause of hospitalization in infants. Inflammation generally produce larger platelets with a high mean platelet volume (MPV). However lower MPVs have also been seen in some chronic and acute inflammatory states. Since CBCs are commonly performed in hospitalized patients, evaluating MPV as a marker of severity in bronchiolitis may help identify patients who may need a higher level of care earlier in their course. Our hypothesis is that MPV may be useful as an indicator of worse disease and an increased need for respiratory support in children with acute bronchiolitis.

Objective: Our objective was to find an association between MPV values and severity of acute bronchiolitis in hospitalized children < 2 years and to explore the association between MPV and severity of respiratory distress and need for oxygen support in hospitalized children with acute bronchiolitis.

Design/Methods:

This was a retrospective chart review. Medical records of all hospitalized children < 2 years were identified using the ICD codes for bronchiolitis and 114 charts met the inclusion criteria. Data collected was age, hospital stay, degree of respiratory distress, respiratory support, admission MPV and RSV. The severity of respiratory distress on admission was calculated using a Clinical Respiratory Distress Score(1-12) and the patients were divided into mild(1-4), moderate(5-8) and severe(9-12) distress. Statistical analysis was done using chi square for association between MPV values and the respiratory distress score and the need for oxygen support. Association was determined between MPV and Respiratory Distress score using chi square test. 

Results:

There was an association between low MPV and higher respiratory distress score (moderate/ severe score) with statistical significance (p< 0.05) [Table 1]. There was also a statistically significant association (p< 0.05) between low MPV and increased need for oxygen support [Table 2].

Conclusion(s):

We found that patients with bronchiolitis and a low MPV had more respiratory distress and also more frequently required oxygen support. This indicates that reductions in MPV can be used as a potential marker for the severity of bronchiolitis as well as the need for oxygen support. Future studies should explore if this has a stronger association with bronchiolitis caused by Respiratory Syncytial Virus.