M. D. DeBarros1, M. W. Causey1, P. Chesley1, M. Martin1,2 1Madigan Army Medical Center,Department Of General Surgery,Tacoma, WA, USA 2Oregon Health And Science University,Department Of Trauma And Critical Care,Portland, OR, USA
Introduction: During surgery, proper fluid resuscitation and hemostatic control is critical. Pleth variability index (PVI) is advocated as an accurate means of optimizing intraoperative fluid resuscitation. PVI is a measure of dynamic change in perfusion index during a complete respiratory cycle. Non-invasive monitoring of total hemoglobin could provide an accurate means to determine the need for transfusion. We analyzed the impact of insufflation and obesity on non-invasive measurements of hemoglobin and PVI in laparoscopic procedures to validate its usefulness in assessing fluid responsiveness and hemoglobin levels.
Methods: A non-invasive hemoglobin and PVI monitoring device was prospectively analyzed in patients undergoing abdominal operations. Patients were stratified by open and laparoscopic approach and obesity (BMI≥35). PVI and hemoglobin values were assessed before, during, and after abdominal insufflation and compared to control patients undergoing open surgery.
Results: 63 patients were enrolled (mean age 42 years; 71% female; mean BMI 36) with 24 patients being laparoscopic non-obese (LN), 20 being laparoscopic obese (LO), and 19 undergoing open operations. There was no significant blood loss in any case. Hemoglobin did not change significantly before or after insufflation (Figure 1a). There was false elevation of PVI with insufflation and more pronounced in obese patients (Figure 1b).
Conclusion: Insufflation or obesity was not associated with significant variations in hemoglobin. Non-invasive monitoring of hemoglobin is useful in laparoscopic procedures in obese and non-obese patients. PVI values should be used cautiously during laparoscopic procedures, particularly in obese patients.
