Platelet Counts and Outcomes in Acute General Pediatric Patients

Background: Platelets are a component of blood with multiple functions including primary hemostasis, immunity, cancer metastasis, and others. Thrombocytopenia is defined as platelet counts less than 150,000 platelets/μl. There are numerous causes of thrombocytopenia but regardless of cause, multiple studies of thrombocytopenia in infants, children, and adolescents admitted to critical care units (neonatal or pediatric) document significant prognostic value for disease severity. However, there is a paucity of information regarding outcomes in children and adolescents with thrombocytopenia admitted to general pediatric floors.

Objective: Better understand the significance of platelet counts and thrombocytopenia in our acute general pediatric patients.

Methods: Retrospective study conducted on pediatric patients (infants, children, and adolescents up to 19 years of age) admitted to the general pediatric floors at OSF HealthCare Children's Hospital between July 2010 to July 2018. Patients' demographics, source of admission, primary diagnosis, length of stay, initial platelet count, and transfer to higher levels of care were analyzed. Platelet counts were grouped into mean platelet count +/- 2 SD and <150/nL, 150-450/nL, >450/nL for data analysis. Those previously diagnosed with hematological or oncological diagnoses as well as those directly admitted to the NICU or PICU were excluded. A T-test and multivariate model were used to deem statistical significance.

Results: 10,858 charts were included in the study after exclusion criteria were met. Of the patients, 48.2% were female and 51.8% male. The mean age was 4.7 (±5.2) years of age. The majority of our general pediatric admissions came from our emergency department followed by outside hospital transfers and then physician offices. The average length of stay was 3.2 days. The mean platelet count was 332.7/nL with a SD of 127.3. We found significance with regards to transfer to higher levels of care in both the mean platelet count with SD and in the grouped platelet counts. Patients with platelet counts <150/nL were 2.9 times more likely to transfer to higher levels of care than those with counts between 150-450/nL (p<.0001, 95% CI 2-4.3) and 2.2 times likely to transfer than those with counts >450/nL (p<.0006, 95% CI 1.4-3.4). Interestingly, we also discovered that outside hospital transfers were more likely to transfer to higher levels of care compared to other sources of admission. Lastly, our top 5 diagnosis categories included: Infection, GI, Kidney/Bladder/Urinary, Neurology, and Muscle Skeletal/Joint.

Conclusion: Previous studies done in the NICU and PICU show that thrombocytopenia is associated with poorer outcomes. Our study suggests that this also holds true in the acute general pediatric patient population. Additionally it gives us insight into common diagnosis categories and admission sources which may have more negative outcomes. Our data supports the concept that providers should be aware of the potential negative impact of thrombocytopenia in the acute pediatric patient and pay them closer attention.