Thank you all very much for your replies! We actually ended up having a brief hematology lecture the other day, which helped shed a little light on things along with your helpful comments. This is probably pretty basic for those experienced RNs out there, but for my fellow students here's a little breakdown to let you know where to look next: Hb and Hct are often confused with each other, but Hemoglobin is a part of RBCs- remember those "heme" we learned about in A&P? Well, how I understand it is that the hemoglobin are kinda like strips of velcro on the RBCs. They pick up O2 from the lungs and carry it around on the RBCs. So- while hemoglobin have to do with RBCs, hematocrit have to do with the percentage of RBCs in the total blood volume. --A low hematocrit reflects a low number of circulating red blood cells. So you have to think about what would actually cause a decrease in circulating RBCs? 1. A decrease in the oxygen-carrying capacity of the RBCs...which would (from what I understand) mean you likely have a decrease in Hgb. Causes of this may include active bleeding, bone marrow disorders, poor diet, or malabsorption of the GI tract. 2. Overhydration. Think about it- if Hct has to do with a percentage of RBCs in the blood, if a patient becomes fluid-overloaded then the blood will become diluted. --A high hematocrit may reflect just the opposite: 1. An increase in the number of erythrocytes 2. A decrease in plasma volume, such as with dehydration or fluid shifts (third spacing). Consider clients with burns, diarrhea, diuretics, erythrocytosis, polycythemia vera, hemachromotosis, or exogenous erythropoitin ( My patient did have slight edema in her extremities, and from what I understand of post-op patients, fluid does some weird stuff and will shift to the site of injury and then elsewhere, which is why you will sometimes see decreased urine output for a while before the fluid finally gets the picture and the patient will begin to void appropriately (based on her input from IVF's and other fluid replacement measures that were administered to make up for blood loss during surgery). So with my client, we saw just that scenario- her foley had been d/c earlier that morning and we were waiting for her to void, but she would only be able to produce 50-100mL urine at a time. Later that afternoon (when her fluid finally shifted back), she was able to produce adequate output. Thanks again for the help! I hope I got this right, but please let me know if I got mixed up on anything! (Oh- and if anyone is hiring someplace beautiful...apparently there's a hiring freeze going on in FL!) ) -S