Background Anemia is associated with morbidity and mortality and frequently leads to transfusion of erythrocytes. We sought to compare directly the effect of high inspired oxygen fraction vs. transfusion of erythrocytes on the anemia-induced increased heart rate (HR) in humans undergoing experimental acute isovolemic anemia. Methods We combined HR data from healthy subjects undergoing experimental isovolemic anemia in seven studies performed by our group. We examined HR changes associated with breathing 100% oxygen by non-rebreathing face mask vs. transfusion of erythrocytes at their nadir hemoglobin (Hb) concentration of 5 g/dL. Data were analyzed using a mixed-effects model. Results HR had an inverse linear relationship to hemoglobin concentration with a mean increase of 3.9 beats per minute per gram of Hb (beats/min/g Hb) decrease (95% confidence interval [CI], 3.7 – 4.1 beats/min/g Hb), P < 0.0001. Return of autologous erythrocytes significantly decreased HR by 5.3 beats/min/g Hb (95% CI, 3.8 – 6.8 beats/min/g Hb) increase, P < 0.0001. HR at nadir Hb of 5.6 g/dL (95% CI, 5.5 – 5.7 g/dL) when breathing air (91.4 beats/min; 95% CI, 87.6 – 95.2 beats/min) was reduced by breathing 100% oxygen (83.0 beats/min; 95% CI, 79.0 -87.0 beats/min), P < 0.0001. The HR at hemoglobin 5.6 g/dL when breathing oxygen was equivalent to the HR at Hb 8.9 g/dL when breathing air. Conclusions High arterial oxygen partial pressure reverses the heart rate response to anemia, probably owing to its usability, rather than its effect on total oxygen content. The benefit of high arterial oxygen partial pressure has significant potential clinical implications for the acute treatment of anemia and results of transfusion trials.

Transfusion-related acute lung injury (TRALI), the leading cause of transfusion-related death, is underreported by clinicians. For TRALI research, a clinician-independent, computerized system has been developed to detect patients with acute respiratory distress posttransfusion. A computer system generates an alert when a blood gas result indicated a PaO2:FiO2 ratio below 300, within twelve hours of blood issued from the blood bank for a patient. The system was prospectively compared to conventional daily rounds in intensive care units (ICUs). We found that ICU rounds detected 9 of 14 patients (64%), while the computer system detected 13 of 14 patients (93%), p = 0.125. ICU rounds took two to three hours per day, while the computer system took one to one and one-half hours per day of investigator time. In conclusion, an automatic computer alert system was more efficient, and was as effective as conventional daily ICU rounds, in detecting patients with posttransfusion acute respiratory distress.

IP firearm assaults against women may be underrepresented in current databases. These assaults are highly lethal, frequently occur at home, and often involve head injury. These observations may lend to strategies for trauma prevention.