A Novel Use of Romiplostim for SARS-CoV-2-induced Thrombocytopenia.

The literature regarding coronavirus disease of 2019 (COVID-19) infection in pediatrics indicates that children have less severe clinical presentations and lower mortality rates. There remains limited data regarding hematologic sequelae in pediatric patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Romiplostim has shown a platelet response in pediatric patients with chronic immune thrombocytopenic purpura, and eltrombopag is proven to increase platelet counts in patients with inherited thrombocytopenia. We review SARS-CoV-2-associated thrombocytopenia and present a pediatric patient with acute on chronic thrombocytopenia in the setting of COVID-19 with subsequent platelet recovery using romiplostim.

Hypoxemia During Extreme Hyperleukocytosis: How Spurious?

BACKGROUND: Spurious hypoxemia has been described in case reports during extreme hyperleukocytosis and has led to recommendations for immediate cooling and analysis of arterial blood gases (ABGs). We sought to determine, in samples processed as recommended, the magnitude of spurious hypoxemia in acute leukemia subjects with hyperleukocytosis. METHODS: A retrospective chart review was conducted of all subjects admitted between 2003 and July 2014 for acute leukemia, who presented with white blood cell (WBC) count > 50 × 10(9) cells/L and had ABGs performed. For each ABG, we collected PaO2 , SaO2 , simultaneous WBC count, and SpO2 when available. Bland and Altman analysis was used to assess the agreement between SpO2 and SaO2 . RESULTS: One-hundred forty-six samples (from 45 subjects) were included, of which 57 samples (from 18 subjects) had data available for Bland and Altman analysis. Mean (SpO2 - SaO2 ) was 2.5%, and 95% CI for limits of agreement between SpO2 and SaO2 was (-10.1,15.1)%. The mean (SpO2 - SaO2 ) was significantly higher for WBC count > 100 × 10(9)/L as compared with WBC count < 100 × 10(9)/L (3.8% vs 0.4%, P = .04), and the 95% CIs for limits of agreement were (-10.3,18)% versus (-7.9,8.6)%. SpO2 and SaO2 were poorly correlated (r(2) = 0.19), whereas the difference (SpO2 - SaO2 ) was fairly correlated with WBC count (r(2) = 0.44). Overall, 11 of 19 samples with WBC count > 150 × 10(9)/L had PaO2 < 55 mm Hg whereas SpO2 was > 94%, the proportion being 5 of 62 samples for WBC count < 150 × 10(9)/L (P < .001). Three subjects with WBC count > 150 × 10(9)/L exhibited large SpO2 to SaO2 differences (10-20%) before leukapheresis, which decreased to below 5% afterward. CONCLUSIONS: In subjects with acute leukemia and hyperleukocytosis, despite cooling and quickly analyzing the samples, we observed poor correlation and agreement between SpO2 and SaO2 , unacceptably low for WBC count > 100 × 10(9)/L. Our results suggest that current guidelines may not totally prevent the diagnosis of spurious hypoxemia.

Initial respiratory status in hyperleukocytic acute myeloid leukemia: prognostic significance and effect of leukapheresis.

This study investigated whether initial respiratory status in hyperleukocytic acute myeloid leukemia (AML), as defined by oxygen/ventilatory support, is (1) associated with early mortality and overall survival and (2) improved after leukapheresis. A retrospective chart review of 89 patients requiring leukapheresis was performed. White blood cell count (WBC) decreased from 153 (56-475) × 10(9)/L to 60 (17-259) × 10(9)/L after first leukapheresis (p < 0.01). Initial respiratory status was room air (n = 40), low (n = 31) or high flow oxygen therapy (n = 8) or mechanical ventilation (n = 10). As compared to admission, respiratory status significantly deteriorated after both first and second leukapheresis (p < 0.01) and was not different at day 5 for patients still alive (p = 0.131). Both day 28 mortality and overall survival were significantly affected by initial respiratory status (p < 0.01). Despite being effective in reducing WBC, leukapheresis did not improve respiratory status of hyperleukocytic AML patients, a factor strongly associated with survival.