A new flexible automated system for the study of exhaled gases.

Expired gas analysis has been largely relegated to the measurement of VO2 and VCO2 by a variety of methods. We designed and built a new flexible automated expired gas analysis instrument, the Volume Accumulating Metabolic Monitor (VAMM), capable of simultaneous and continuous quantitative expired gas analysis for a multiplicity of gas species. All expired gas is collected into one of two twin reservoirs.

Competing autonomic mechanisms precede the onset of postoperative atrial fibrillation.

Objectives: This study was designed to evaluate autonomic changes preceding atrial fibrillation/flutter (AF) after thoracotomy.

Background: Autonomic fluctuations before the onset of postoperative AF have been reported but with conflicting results.

Methods: In 48 patients with postoperative AF, 2-h Holter recordings before the onset of AF were compared with corresponding data from 48 age- and gender-matched surgical controls without AF.