The diagnosis and management of hypoxemic respiratory
failure is part of the daily routine of anesthesiologists,
intensivists, and respiratory therapists. However, identification
of some pathological states can be challenging, and
failure to rapidly diagnose them can lead to inappropriate
therapeutic decisions with expensive and potentially severe
adverse consequences. These decisions can range from
unnecessary intubation and mechanical ventilation to inappropriate
administration of bicarbonate for false acidosis
and consequent worsening of any existing metabolic
abnormality. Additionally, performing unnecessary tests,
such as computerized tomographic angiography to rule out
pulmonary embolism, may negatively affect the kidneys,
due to the intravenous iodine contrast. We report the case
of a patient with hyperleukocytosis secondary to myelofibrosis
who presented with altered mental status and pseudo-hypoxemia.
We discuss the differential diagnoses of
hypoxemia in this setting and the role of point-of-care
arterial blood gas (ABG) analysis in diagnosing pseudohypoxemia.