Achmet Ali, Yeşer Dorman, Taner Abdullah, Ceren Yaşa, Demet Altun, İbrahim Özkan Akıncı, Mukadder Orhan Sungur, Perihan Ergin ÖzcanDepartment of Anesthesiology and Reanimation, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
BACKGROUND AND AIM: Pulse pressure variation (PPV) and stroke volume variation (SVV) can predict fluid responsiveness effectively. However, high body mass index (BMI) can restrict their use due to changes in respiratory system compliance (CS), intra-abdominal pressure, and stroke volume (SV) in the prone position. Therefore, we aimed to investigate the effectiveness of mini fluid challenge in predicting fluid responsiveness in obese (BMI >30 kg/m2) patients in the prone position.
METHODS: A total of 33 patients undergoing neurosurgery were included. After standardized anesthesia induction, patients' PPV, SVV, stroke volume index (SVI) and CS values were recorded in the prone position (T1) after infusion of 100 ml crystalloid (T2) and after fluid loading was completed with additional 400 ml of crystalloid. Patients whose SVI increased more than 15% after the fluid loading were defined as volume responders.
RESULTS: Fifteen (45%) patients were responders to 500 ml fluid loading. After the 100 ml fluid load, a higher percentage increase in SVI was observed among responders (p <0.001), with values of 6.6% (6.28.6%) and 3.5% (1.74.8%) in responders and non-responders, respectively. Areas under the ROC of MFC, PPV, and SVV were 0.967 (95% CI: 0.8380.999), 0.683 (95% CI: 0.4990.834), and 0.709 (95% CI: 0.5260.853), respectively. The AUC of MFC was significantly higher than that of PPV (p=0.003) and SVV (p=0.005).
CONCLUSIONS: Our results suggest that the increase in SVI after a rapid infusion of 100 ml crystalloid could predict fluid responsiveness with good specificity and sensitivity in patients with BMI >30 kg/m2 in the prone position. With this method, it is possible to optimize fluid therapy and improve the outcomes of hypovolemia and hypervolemia in the aforementioned patient group.