Blood Gas Analysis Health Article

Health care team roles

A physician, nurse, respiratory care technician, or laboratory technician collects the blood sample by arterial puncture and sees to the timely and appropriate transport to the laboratory for analysis. A member of the health care team should observe the patient for 10–15 minutes to ensure that bleeding from the puncture site has stopped. Blood gas measurements are performed by a registered respiratory therapist, RRT; certified respiratory technician, CRTT; clinical laboratory scientist CLS (NCA) or medical technologist MT (ASCP); clinical laboratory technician CLT (NCA) or medical laboratory technician MLT (ASCP). A physician interprets the blood gas analysis results with a thorough understanding of the acid-base chemistry and physiology of blood and in view of the clinical situation, and applies the results to the diagnosis, treatment, and management of the patient.

KEY TERMS

Acid—A chemical compound that reacts with a base to form a salt, that can give off hydrogen ions in water solution, or that contains an atom that can accept a pair of electrons from a base.

Acidosis—A blood condition in which the pH is < 7.35 and the bicarbonate concentration is below normal.

Alkalosis—A blood condition in which the pH is > 7.45 and the bicarbonate concentration is above normal.

Base—A chemical compound that reacts with an acid to form a salt, that takes up or accepts protons, or that contains an atom with a free pair of electrons to be donated to an acid.

Buffer—A chemical substance that resists changes in pH in response to changes in acid and base concentration; a buffer system consists of a weak acid or weak base in combination with its salt.

Hemoglobin—The red–colored, iron-containing protein in red blood cells that carries oxygen to the tissues.

Heparin—A biochemical that may be isolated from various animal tissues that has anticoagulant properties.

Ketoacidosis—An excessive level of acid accompanied by an increase in the level of ketones in blood that occurs as a complication of diabetes mellitus; ketones are substances normally processed by the liver from fats.

Oxygen saturation of hemoglobin—The percentage of hemoglobin that is bound to oxygen.

pH—An exponential measurement scale for expressing the concentration of acid in solution pH = -log [H⁺].

BOOKS

Burtis, C.A., and E.R. Ashwood, eds. Fundamentals of Clinical Chemistry. 5th ed. Philadelphia: Saunders, 2001.

Marshall, William J. Clinical Chemistry 4th ed. Edinburgh, London, New York, Philadelphia, St. Louis, and Toronto: Mosby, 2000.

OTHER

Argyle, B. Mad Scientist Software, Blood Gases Computer Program Manual. 1996 Mad Scientist Software, Alpine UT. <http://www.madsci.com/manu/gas_acid.htm>.

Clinical Web Server 2. University of Kansas Medical Center. <http://clinweb2.kumc.edu/>.

HealthCentral website. 1998 A.D.A.M. Software, Inc. <http://www.healthcentral.com/mhc/top/003855.cfm>.

Patricia L. Bounds, Ph.D.