Effect of an infusion device on the integrity of whole blood and packed red blood cells.

The effects of the Gemini PC-2 linear peristaltic infusion device on the integrity of packed red blood cells (RBC) and whole blood products are reported. Thirty-eight units of blood products were infused at rates of 999, 100, 50, and 5 mL/hr under simulated clinical conditions. To evaluate the effect of hematocrit on cell survival, fresh and stored packed RBCs preserved with adenine-saline 3 (AS-3) and fresh and stored packed RBCs and fresh and stored whole blood preserved with citrate-phosphate-dextrose-adenine 1 (CPDA-1) were used. No two units tested came from the same donor. Plasma potassium and plasma free hemoglobin concentrations were determined before and after simulated infusion for 80 experimental runs. Preinfusion plasma potassium and free hemoglobin concentrations varied significantly among the blood products. Stored products were associated with higher plasma potassium and free hemoglobin levels than fresh units, both before and after infusion. Concentrations also differed significantly between AS-3-preserved and CPDA-1-preserved fresh and stored packed RBCs. Infusion did not change plasma potassium values appreciably under any conditions. Plasma free hemoglobin increased in the fresh products only. Donor-specific differences were significant for potassium but not for free hemoglobin. There was no significant effect of infusion rate on either biochemical marker. In all the experimental runs, less than 0.01% of cells were lysed. The Gemini PC-2 linear peristaltic infusion device delivered a variety of blood products at a wide range of infusion rates without inducing a substantial degree of hemolysis.

Coagulase-negative staphylococci: incidence, pathogenicity, and treatment in the 1990s.

Coagulase-negative staphylococci (CNS), which historically have been viewed as contaminants when recovered in culture media, are now recognized as opportunistic pathogens of increasing importance in hospital-acquired infections. They are frequently found colonizing prosthetic devices and intravenous lines. CNS are capable of producing a variety of infections including deep-seated infections such as endocarditis and meningitis. Staphylococcus epidermidis is the most commonly isolated CNS and it appears to be the most resistant to antibiotics, making antimicrobial therapy challenging. Treatment of the infection will very often require removal of a prosthetic device, if present. An adequate infection control program is imperative in prophylaxis against this infection.