Method of Gennis et al for Ordering Chest Radiographs to Evaluate Possible Pneumonia

 

Variables:

(1) temperature > 37.8°C

(2) pulse > 100 beats/minute

(3) respirations > 20 breaths/minute

 

If one or more of the variables is present in an adult, then chest X-rays should be ordered.

 

If none of the variables are present, then it is not necessary to order chest X-rays.

 

Assessment:

• Gennis found the rule 97% sensitive for detecting radiographically apparent pneumonia.

• An evaluation by Emerman et al (1991) showed the Gennis rule to be less sensitive than physician judgment, but more specific and accurate.