Autotriggering caused by cardiogenic oscillation is common in postcardiac surgery patients when flow triggering is used. Autotriggering occurred more often in patients with more dynamic circulation. Autotriggering caused respiratory alkalosis and hyperinflation of the lungs.

In most patients, the pulse method provides bedside measurement of BV without blood sampling (except for hemoglobin determination), with an estimated error less than 10%. In 10-30% of tests the method failed because of motion distortion of the record during the 10-min data collection period or because of insufficient pulse amplitude in the test tissue.