Pulse pressure variation as a tool to detect hypovolaemia during pneumoperitoneum

Abstract

Background: Pulse pressure variation (ΔPP) and systolic pressure variation (SPV) induced by mechanical ventilation have been proposed to detect hypovolaemia and guide fluid therapy. During laparoscopic surgery, chest compliance is decreased by pneumoperitoneum. This may affect the value of SPV and ΔPP as indicators of intravascular volume status. Thereby, we investigated the effects of pneumoperitoneum and hypovolaemia on SPV and ΔPP.Methods: We measured ΔPP, SPV and the inspiratory (Δup) and expiratory (Δdown) components of SPV, at baseline, during pneumoperitoneum, during pneumoperitoneum and hypovolaemia and after the return to baseline conditions, in 11 mechanically ventilated rabbits. Pneumoperitoneum was induced by inflating the abdomen with carbon dioxide, and hypovolaemia was induced by controlled haemorrhage.Results: Pneumoperitoneum induced an increase in SPV from 8.5 ± 1.6 to 13.3 ± 2.6 mmHg (+56%, P < 0.05) as a result of an increase in Δup from 2.0 ± 1.0 to 6.7 ± 2.1 mmHg (+236%, P < 0.05), but no significant change in Δdown, nor in ΔPP. Haemorrhage induced a significant (P < 0.05) increase in SPV from 13.3 ± 2.6 to 19.9 ± 3.7 mmHg (+50%), in Δdown from 6.6 ± 3.3 to 14.0 ± 4.9 mmHg (+112%) and in ΔPP from 11.1 ± 4.8 to 24.9 ± 9.8% (+124%) but no change in Δup. All parameters returned to baseline values after blood re‐infusion and abdominal deflation.Conclusions: SPV is modified by haemorrhage but it is also influenced by pneumoperitoneum. In contrast, ΔPP is modified by haemorrhage but not by pneumoperitoneum. These findings suggest that ΔPP should be used preferentially instead of SPV to detect hypovolaemia and guide fluid therapy during laparoscopic surgery.

Does pneumoperitoneum affect perfusion index and pleth variability index in patients receiving combined epidural and general anesthesia?

“…This reported lack of increase in SVV is questionable because in all reported animal studies (12)(13)(14)(15), SVV increased after elevation of intra-abdominal pressure and/or pneumoperitoneum. We recently found that pneumoperitoneum increased SVV in humans (6), and furthermore, many animal studies showed that other dynamic indices such as systolic pressure variation and pulse pressure variation (23,24) also increased during intra-abdominal hypertension (12)(13)(14)(15)(25)(26)(27) Our results relating to PVI and SVV after pneumoperitoneum were different than those of Høiseth et al (11) and Liu et al (3), and the reason for the discrepancy is unclear. However, we suppose this relates to differences in study design.…”

Pulse pressure variation and stroke volume variation predict fluid responsiveness in mechanically ventilated patients experiencing intra-abdominal hypertension

“…Appropriate fluid therapy is of the utmost importance for optimizing cardiac performance and organ perfusion during IAH (15). It has been shown that cardiac filling pressures, such as CVP and pulmonary artery occlusion pressure, in the presence of elevated IAP may be falsely increased, hence misleading adequate fluid therapy (16). Recently, it has been demonstrated that elevated IAP increases the static variables of preload such as PPV and systolic pressure variation (SPV), especially in cases of hypovolemia (17,18).…”

The polycompartment syndrome: a concise state-of-the-art review

“…Fluid responsiveness in IAH is defined as a PPV above 20% rather than the usual 12% threshold. Systolic pressure variation should not be used in the setting of increased IAP or ITP because the increase seen in IAH and ACS only reflects a ΔUp phenomenon [67,68]. 8.…”