Continuous noninvasive monitoring of respiratory rate in critically ill patients.

Respiratory rate is a sensitive clinical parameter in a multitude of pulmonary diseases, especially in the critical care setting. In order to validate the routine recording of the respiratory rate in the intensive care unit, we compared the values obtained from the nursing records with the breathing frequency continuously recorded by a prototype microprocessor system using respiratory inductive plethysmography. We found a significant (greater than or equal to 20 percent) error in the staff's monitoring of respiratory rate one third of the time. In addition, we demonstrated the ease and reliability of using this prototype system as a continuous, noninvasive, long-term respiratory monitor in the intensive care unit.