Platelet count decline and high neutrophil count within the first day of admission for painful sickle cell vaso-occlusive episodes predict severe complications 2 a All complications is defined as having any of acute pulmonary events, acute kidney injury, acute liver injury, thromboembolism, stroke, exchange transfusion, ICU or death. Vaso-occlusive pain crisis (VOC) is the primary reason for emergency room (ER) visits and hospitalizations in sickle cell disease (SCD).[1] Organ damage can occur in the lungs and other visceral organs during VOC.[[2], [4]] Platelet count decline was reported to predict acute chest syndrome[[5]] and other severe complications[7] during hospitalization for VOC. To reflect change over time, proportional platelet or neutrophil counts with respect to Baseline (count ratio ER/Baseline, First morning/Baseline and Platelet Nadir/Baseline) and ER (First Morning/ER and Platelet Nadir/ER) were also assessed. [Extracted from the article]