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Can changes in arterial pressure be used to detect changes in cardiac output during volume expansion in the
Yannick Le Manach1, Christoph K Hofer, Jean-Jacques Lehot
1Department of Anesthesiology and Critical Care Medicine, Centre Hospitalier Universitaire Pitié-Salpêtrière, Paris, France.
Insights
Pulse pressure variation accurately detects changes in cardiac output (CO) during fluid administration, unlike arterial pressure. This finding is crucial for guiding volume expansion (VE) in perioperative settings.
Area of Science:
- Anesthesiology
- Critical Care Medicine
- Hemodynamics
Background:
- Cardiac output (CO) monitoring is infrequent during surgery.
- Arterial pressure is the primary hemodynamic indicator for volume expansion (VE) effects.
- The accuracy of arterial pressure in reflecting CO changes post-VE is unproven.
Purpose of the Study:
- To evaluate VE-induced changes in arterial pressure and pulse pressure variation (PPV) for detecting CO changes.
- To assess the reliability of hemodynamic parameters in perioperative fluid management.
Main Methods:
- A study involving 402 patients across four centers.
- Hemodynamic variables recorded pre- and post-VE.
- Response to VE defined as >15% increase in CO; gray zone approach used for analysis.
Main Results:
- 51% of patients showed a >15% CO increase after VE.
- Arterial pressure parameters had low predictive values (AUC 0.64-0.70) and large gray zones (>60% inconclusive).
- A PPV decrease of ≥3% accurately identified a >15% CO increase (90% sensitivity, 77% specificity).
Conclusions:
- Only pulse pressure variation reliably detects VE-induced CO changes.
- PPV demonstrates significant clinical applicability in guiding fluid therapy.
Background:
Cardiac output (CO) is rarely monitored during surgery, and arterial pressure remains the only hemodynamic parameter for assessing the effects of volume expansion (VE). However, whether VE-induced changes in arterial pressure accurately reflect changes in CO has not been demonstrated. The authors studied the ability of VE-induced changes in arterial pressure and in pulse pressure variation to detect changes in CO induced by VE in the perioperative period.
Methods:
The authors studied 402 patients in four centers. Hemodynamic variables were recorded before and after VE. Response to VE was defined as more than 15% increase in CO. The ability of VE-induced changes in arterial pressure to detect changes in CO was assessed using a gray zone approach.
Results:
VE increased CO of more than 15% in 205 patients (51%). Areas under the receiver operating characteristic curves for VE-induced changes in systolic, diastolic, means, and pulse pressure ranged between 0.64 and 0.70, and sensitivity and specificity ranged between 52 and 79%. For these four arterial pressure-derived parameters, large gray zones were found, and more than 60% of the patients lay within this inconclusive zone. A VE-induced decrease in pulse pressure variation of 3% or more allowed detecting a fluid-induced increase in CO of more than 15% with a sensitivity of 90% and a specificity of 77% and a gray zone between 2.2 and 4.7% decrease in pulse pressure variation including 14% of the patients.
Conclusion:
Only changes in pulse pressure variation accurately detect VE-induced changes in CO and have a potential clinical applicability.
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