Clinical and Experimental Circulation
Background and Goal of Study: Application of PEEP in mechanically ventilated patients prevents intraoperative hypoxemia, which is caused by closing of alveoli and V/Q mismatch. However, PEEP is associated with negative hemodynamic effects and reduction in cardiac output (CO).The increase of intra-abdominal pressure (IAP) also affects both cardiac and lung function. The aim of this study was to record the effect of PEEP in CO before and after pneumoperitoneum application.
Materials and Methods: 52 patients [age: 49.5±14.4 yrs;BMI:27.3±3.8 and ASA-PS classification: 1–3] undergoing laparoscopic cholecystectomy, were evaluated during two different time periods. CO was measured noninvasively with an Oesophageal Doppler Monitor-ODM before and after pneumoperitoneum was obtained to 12mmHg during time period A and B respectively under 5 conditions: at 0, 5, 10, 15cm H2O of PEEP and when the ventilator was disconnected. The standard monitoring applied consisted of EEG, IBP, ETCO2, BIS and pulmonary parameters. To compare the five protocol phases, ANOVA was utilized for repeated measurements and paired t-test between the two groups.
Results and Discussion: The CO alterations during time period A and B are shown in Figure 1 and Table 1. The effects of different PEEP levels during time period A are similar as described in the literature. During time period B, incremental increase of PEEP enhanced CO, which was tremendously reduced after the ventilator disconnection.
Conclusion(s): According to the results of this study the application of PEEP during laparoscopic surgery could protect the cardiac function, improve CO and serve as a very useful tool in cases of increased IAP. Further evaluation of this suggestion and of its potential clinical implications merit more detailed study.© 2010 European Society of Anaesthesiology