SIRS criteria: is it oral or rectal temperature? Harrison's vs the rest: who is more authoritative?

Uptated June 29, 2011

1. - Respiratory rate

Harrison's Online 17th Edition Chapter 265 (Chap. 254 16th Edition) claims in SIRS criteria: tachypnea (>24 breaths/min). 

Medscape (and Sleisenger and Fordtran's Gastrointestinal and Liver Disease 9th Ed. Chap. 58 p. 973) state it's 20 breaths/min.

I am aware this seemingly doesn't change clinical decisions - as trachypnea is part of a broader picture - but still numbers are numbers. 

2. - Fever

Harrison's: oral temperature >38°C

Medscape (and Sleisenger and Fordtran's): rectal temperature greater than 38°C

Uptodate 19.1: Temperature >38.5°C or <35.0°C
Data from: Annane, D, Bellissant, E, Cavaillon, JM. Septic shock. Lancet 2005; 365:63.

Rectal and oral temperatures are not the same, being rectal + 0,4 °C oral.

3. - Procalcitonin. Harrison's doesn't mention this laboratory finding. Medscape does. 

Thanks for your attention and comments & suggestions.