Dictionary

Labs and diagnostics

Lab values with their normal and critical ranges, and the tests nurses prepare clients for.

radiopaqueBlocking x-rays, so the material shows up white on an x-ray image.

rapid plasma reaginA blood test used to screen for syphilis by looking for antibodies the body makes during the infection.

red blood cellA blood cell that carries oxygen from the lungs to the body's tissues; also called an erythrocyte.

red blood cell countA blood test that counts the red blood cells in a set amount of blood.

reference rangeThe range of results for a lab test that is expected in healthy people, also called the normal range.

respiratory acidosisA state in which the blood becomes too acidic because the lungs do not remove enough carbon dioxide.

respiratory alkalosisAn acid-base imbalance in which breathing out too much carbon dioxide makes the blood too alkaline.

reticulocyte countA blood test that measures reticulocytes, young red blood cells newly released from the bone marrow.

Rh factorA protein that may be present on the surface of red blood cells; people who have it are Rh-positive and those without it are Rh-negative.

RT-PCRReverse transcription polymerase chain reaction: a lab test that finds the genetic material of a virus or other germ in a sample.