Significance of platelet count in children admitted with bronchiolitis

Table 1 Characteristics of 305 children admitted with bronchiolitis

	Platelet count (× 109/L) n (%) or mean ± SD		P value
	> 500	< 500
Children	217 (71)	88 (29)
Age (mo)	7.3 ± 5.8	4.8 ± 4.1	< 0.0011
Males	132 (74)	47 (26)	0.22
Born < 38 wk gestation	32 (65)	17 (35)	0.32
Duration of illness before admission (d)	2.9 ± 1.2	2.7 ± 1.4	0.31
Fever (> 38 °C) on admission	148 (73)	55 (27)	0.32
Blood white cell count (× 109/L)	3.5 ± 1.1	3.2 ± 0.5	0.81
Nasopharyngeal aspirate isolate
RSV	189 (74)	66 (26)
Adenovirus	13 (57)	10 (43)
Influenza	6 (46)	7 (54)	0.09
RSV + Adenovirus	5 (62)	3 (38)
RSV + Influenza	3 (50)	3 (50)
Serum CRP (mg/L)	1.4 ± 1.3	1.5 ± 1.2	0.51
Duration of hospitalization (d)	4 ± 5.5	4.4 ± 4.2	0.61
Admitted to intensive care	25 (62)	15 (37)	0.22

¹t-test;

²χ² test or Fisher exact test if number < 5. n: Number of infants; SD: Standard deviation; RSV: Respiratory syncytial virus; CRP: C-reactive protein.

Table 2 Thrombocytosis (platelet count > 500 × 10⁹/L) and number of pathogenic viruses identified on nasopharyngeal aspirates of 305 children with bronchiolitis

No. of virus isolated	Total	Thrombocytosis n (%)	Odds	OR (95%CI)	P value
One	291	82 (28)	0.4	1.0 (reference)	0.2
Two	14	6 (43)	0.75	1.9 (0.6-5.7)

n: Number of infants; OR: Odds ratio; CI: Confidence intervals.

Table 3 Degree of thrombocytosis and outcomes in 305 children with bronchiolitis

	Thrombocytosis, n (%)				P value
	None (n = 217)	Mild (n = 78)	Moderate (n = 9)	Severe (n = 1)
Mean (SD) duration of hospitalization in days	4.0 (5.5)	4.4 (4)	4.5 (3)	5.0 (0)	0.91
Admission to ICU	25 (11)	25 (30)	3 (33)	0 (0)	0.22

¹ANOVA with Bonferroni correction for multiple comparisons;

²Fisher exact test. n: Number of infants; Thrombocytosis: None if platelet level < 500 × 10⁹/L; mild if 500 to 700 × 10⁹/L; moderate if 700 to ≤ 900 × 10⁹/L and severe if > 900 × 10⁹/L. ICU: Intensive care unit.