LAUSR

Hyperleukocytosis can cause respiratory failure due to pulmonary leukostasis. Additionally, gas tests can confirm the presence of pseudo-hypoxemia and the patient may end up receiving unnecessary treatments if undiagnosed. We hereby present the case of a 25-year-old male with chronic myeloid leukemia (CML) diagnosed 10 years ago and with poor adherence to medical treatment. The patient was admitted to the ER with asthenia and adynamia of 2-week duration complicated with dyspnea over the last 24 hours. The patient remained apyretic and lucid during the physical examination with polypnea at 29 rpm, diffuse crepitant rattle, and pulse oximetry (SpO2) values no less than 90% with oxygen therapy through a low-flow face mask. Hemodynamically stable. Distended abdomen, hepatomegaly, and grade V splenomegaly. The blood test sample showed the following values: hemoglobin, 3.6 g/dL; leukocytosis, 688 000 cells/ L; platelets 321 000 cells/ L. Peripheral blood swab sample consistent with CML in chronic stage. The chest X-ray confirmed the presence of right para hilar region discreet opacity. The patient was admitted to the intensive care unit (ICU) with low respiratory work and non-invasive mechanical ventilatory support (MVS) was initiated. Thirty (30) minutes later, the patient started feeling confused, polypneic (30--35 rpm) and with thoracoabdominal asynchrony. Even though the SpO2 was 95%, the arterial-blood gas test conducted (Radiometer ABL800 FLEX, Denmark) confirmed the presence of severe respiratory failure: PaO2 = 50 mmHg, PaCO2 = 38 mmHg, values of arterial blood oxygen saturation (SaO2) of 86% (fraction of inspired oxygen = 0.6, pressure support ventilation = 8 cmH2O, positive end-expiratory pressure = 9 cmH2O). We proceeded with orotracheal intubation and invasive MVS. On suspicion of leukostasis-induced respiratory failure, cytoreductive therapy was started with the administration of hydroxyurea and leukapheresis associated with the molecular therapy of CML with dasatinib. Red-cell concentrates were transfused to solve the anemia.