[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
July 18, 1990

Laboratory Critical Limits-Reply

Author Affiliations

University of California—Davis

University of California—Davis

JAMA. 1990;264(3):335. doi:10.1001/jama.1990.03450030050020

In Reply.—  We have conducted two parallel national surveys of critical limits. One covered a broad cross section of medical institutions and trauma centers, the other, children's hospitals (Table). The table summarizes the use of SI units for representative critical limit tests and gives the factors for conversion of conventional to SI units.1 These results (from 92 US medical centers and 39 children's hospitals) lead to the following observations: (1) The majority of hospitals used conventional units, (2) electrolytes with simple conversion factors (eg, × 1) were often listed with SI units, (3) some tests introduced recently (eg, free or "ionized" calcium) were listed with SI units, (4) tests with methods traditionally using SI units (eg, ammonia) were listed that way, (5) tests with noninteger conversion factors (eg, glucose and bilirubin) generally were listed with conventional units, and (6) hematology and blood gas tests were listed with conventional