BACKGROUND Although traditionally associated with polycythemia, COPD has a systemic inflammatory component that could interfere with erythropoiesis. This study describes the distribution and prognostic value of the hematocrit in patients with severe COPD receiving long-term oxygen therapy (LTOT). METHODS A total of 2,524 patients with COPD, FEV1/vital capacity (VC) < 70%, FEV1 < 80% of predic...

CONTEXT Elderly patients are at high risk of both abnormal hematocrit values and cardiovascular complications of noncardiac surgery. Despite nearly universal screening of patients for abnormal preoperative hematocrit levels, limited evidence demonstrates the adverse effects of preoperative anemia or polycythemia. OBJECTIVE To evaluate the prevalence of preoperative anemia and polycythemia and...

Physiological studies on fetal blood in narrow glass tubes have suggested that fetal optimal hematocrit (hct) might be as high as 60%. A theoretical 'ideal' hct can also be predicted with a theoretical curve of hematocrit/viscosity (h/η) ratio vs hct constructed with Quemada's model. We used the database of one of our previous papers on fetal hemorheology to reinterpret its results with this co...

The rates of washout of 133Xe and 131I-iodoantipyrine from the myocardium into the coronary sinus blood were determined over a wide range of hematocrits after simultaneous injection of the isotopes into the left anterior descending coronary artery of dogs. The ratio of the monoexponential disappearance constants (kX/kI), which is a measure of the ratio of the dynamic blood-tissue partition coef...

Results: A total of 33 undergraduates were studied. The hematocrit, plasma viscosity and plasma fibrinogen were significantly higher in smokers than non-smokers (P < 0.01). Postexercise plasma viscosity was significantly higher than pre-exercise value in non-smokers (P < 0.0001). Hematocrit, plasma viscosity and plasma fibrinogen were also significantly higher post-exercise in smokers (P < 0.01...

This paper discusses a current misinterpretation between different parameters of hemoglobin concentration measurement and its amplification under conditions of blood loss. The paper details the distinction between microcirculatory hematocrit and the hematocrit of the macrocirculation to analyze clinical use of real-time patient hemoglobin concentration measurement by noninvasive point-of-care d...