Respiratory rate as an indicator of acute respiratory dysfunction.

To assess respiratory rate as an indicator of acute respiratory dysfunction, we studied 58 consecutive patients four times daily during the postoperative period. Of 825 measurements of respiratory rate, 726 (89%) were normal (24/min or less). Elevations in respiratory rate without respiratory dysfunction were found in only 4% of all measurements. Patients without lung disease had a mean respiratory rate of 18 +/- 4/min, while patients with an abnormal respiratory rate and respiratory dysfunction had a mean of 27 +/- 5/min. Our study demonstrates that respiratory rate, if carefully measured, is a sensitive and reasonably specific marker of acute respiratory dysfunction.