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Using heart-lung interactions to assess fluid responsiveness during mechanical ventilation.

Michard F, Teboul JL - Crit Care (2000)

Bottom Line: Mechanical ventilation induces cyclic changes in left ventricular (LV) stroke volume, which are mainly related to the expiratory decrease in LV preload due to the inspiratory decrease in right ventricular (RV) filling and ejection.In the present review, we detail the mechanisms by which mechanical ventilation should result in greater cyclic changes in LV stroke volume when both ventricles are 'preload dependent'.We also address recent clinical data demonstrating that respiratory changes in arterial pulse (or systolic) pressure and in Doppler aortic velocity (as surrogates of respiratory changes in LV stroke volume) can be used to detect biventricular preload dependence, and hence fluid responsiveness in critically ill patients.

View Article: PubMed Central - PubMed

Affiliation: Service de Réanimation Medicale, CHU de Bicêtre, Université Paris XI, Kremlin Bicêtre, France. f.michard@wanadoo.fr

ABSTRACT
According to the Frank-Starling relationship, a patient is a 'responder' to volume expansion only if both ventricles are preload dependent. Mechanical ventilation induces cyclic changes in left ventricular (LV) stroke volume, which are mainly related to the expiratory decrease in LV preload due to the inspiratory decrease in right ventricular (RV) filling and ejection. In the present review, we detail the mechanisms by which mechanical ventilation should result in greater cyclic changes in LV stroke volume when both ventricles are 'preload dependent'. We also address recent clinical data demonstrating that respiratory changes in arterial pulse (or systolic) pressure and in Doppler aortic velocity (as surrogates of respiratory changes in LV stroke volume) can be used to detect biventricular preload dependence, and hence fluid responsiveness in critically ill patients.

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Related in: MedlinePlus

Respiratory changes in airway and arterial pressures in a mechanically ventilated patient. The pulse pressure (systolic minus diastolic pressure) is maximal (PPmax) at the end of the inspiratory period and minimal (PPmin) three heart beats later (ie during the expiratory period). The respiratory changes in pulse pressure (ΔPP) are calculated as the difference between PPmax and PPmin, divided by the mean of the two values, and expressed as a percentage (see text for details). Adapted with permission [33].
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Figure 5: Respiratory changes in airway and arterial pressures in a mechanically ventilated patient. The pulse pressure (systolic minus diastolic pressure) is maximal (PPmax) at the end of the inspiratory period and minimal (PPmin) three heart beats later (ie during the expiratory period). The respiratory changes in pulse pressure (ΔPP) are calculated as the difference between PPmax and PPmin, divided by the mean of the two values, and expressed as a percentage (see text for details). Adapted with permission [33].

Mentions: where PPmax and PPmin are the maximal and minimal values of pulse pressure over a single respiratory cycle, respectively (Fig. 5).


Using heart-lung interactions to assess fluid responsiveness during mechanical ventilation.

Michard F, Teboul JL - Crit Care (2000)

Respiratory changes in airway and arterial pressures in a mechanically ventilated patient. The pulse pressure (systolic minus diastolic pressure) is maximal (PPmax) at the end of the inspiratory period and minimal (PPmin) three heart beats later (ie during the expiratory period). The respiratory changes in pulse pressure (ΔPP) are calculated as the difference between PPmax and PPmin, divided by the mean of the two values, and expressed as a percentage (see text for details). Adapted with permission [33].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC137257&req=5

Figure 5: Respiratory changes in airway and arterial pressures in a mechanically ventilated patient. The pulse pressure (systolic minus diastolic pressure) is maximal (PPmax) at the end of the inspiratory period and minimal (PPmin) three heart beats later (ie during the expiratory period). The respiratory changes in pulse pressure (ΔPP) are calculated as the difference between PPmax and PPmin, divided by the mean of the two values, and expressed as a percentage (see text for details). Adapted with permission [33].
Mentions: where PPmax and PPmin are the maximal and minimal values of pulse pressure over a single respiratory cycle, respectively (Fig. 5).

Bottom Line: Mechanical ventilation induces cyclic changes in left ventricular (LV) stroke volume, which are mainly related to the expiratory decrease in LV preload due to the inspiratory decrease in right ventricular (RV) filling and ejection.In the present review, we detail the mechanisms by which mechanical ventilation should result in greater cyclic changes in LV stroke volume when both ventricles are 'preload dependent'.We also address recent clinical data demonstrating that respiratory changes in arterial pulse (or systolic) pressure and in Doppler aortic velocity (as surrogates of respiratory changes in LV stroke volume) can be used to detect biventricular preload dependence, and hence fluid responsiveness in critically ill patients.

View Article: PubMed Central - PubMed

Affiliation: Service de Réanimation Medicale, CHU de Bicêtre, Université Paris XI, Kremlin Bicêtre, France. f.michard@wanadoo.fr

ABSTRACT
According to the Frank-Starling relationship, a patient is a 'responder' to volume expansion only if both ventricles are preload dependent. Mechanical ventilation induces cyclic changes in left ventricular (LV) stroke volume, which are mainly related to the expiratory decrease in LV preload due to the inspiratory decrease in right ventricular (RV) filling and ejection. In the present review, we detail the mechanisms by which mechanical ventilation should result in greater cyclic changes in LV stroke volume when both ventricles are 'preload dependent'. We also address recent clinical data demonstrating that respiratory changes in arterial pulse (or systolic) pressure and in Doppler aortic velocity (as surrogates of respiratory changes in LV stroke volume) can be used to detect biventricular preload dependence, and hence fluid responsiveness in critically ill patients.

Show MeSH
Related in: MedlinePlus