title: Ventilation parameters used to guide cardiopulmonary function during mechanical ventilation.
abstract: OBJECTIVE
  To describe the newly introduced ventilation parameters that are used at the bedside to estimate cardiopulmonary function during positive pressure ventilation (PPV).
  
  
  RESULTS
  PPV induces right atrial pressure changes over the ventilator cycle. Positive end-expiratory pressure-induced central venous pressure changes and pulse pressure variation have been introduced as parameters that predict fluid responsiveness. Pulse pressure variation seems to be valid even at low tidal volume ventilation. A capnometer can be used to measure low perfusion lung area and to monitor the continuous breath-by-breath cardiac output of ventilated patients. Ultrasound evaluation of the lung parenchyma and diaphragm status is likely to become more popular. To evaluate ventilator settings, functional residual capacity (FRC) measurement and visual lung recruitment estimation via electric impedance tomography (EIT) have been introduced.
  
  
  CONCLUSIONS
  The utility of lung ultrasound is expanding. Although the clinical implications of FRC measurement and lung monitoring with imaging tools such as EIT are starting to be realized, their efficacy in severe hypoxic respiratory failure should be evaluated further in well designed clinical trials. To improve the preemptive management of impending respiratory failure, an alarm index that integrates noninvasive cardiopulmonary function parameters should be developed.
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Jin-Won
authors.initials: JW
authors.lastname: Huh
authors.forename: Younsuck
authors.initials: Y
authors.lastname: Koh
mesh_terms: D006334:Heart Function Tests / Q000379:methods*; D006801:Humans; D008991:Monitoring, Physiologic / Q000379:methods; D011175:Positive-Pressure Respiration / Q000379:methods*; D012129:Respiratory Function Tests / Q000379:methods*