Hemodynamic Changes and Fluid Shifts After Large-Volume Fluid Infiltration: Results From a Porcine Model

The role of transesophageal echocardiography in the intraoperative period

The goal of hemodynamic monitoring and management during major surgery is to guarantee adequate organ perfusion, a major prerequisite for adequate tissue oxygenation and thus, end-organ function. Further, hemodynamic monitoring should serve to prevent, detect, and to effectively guide treatment of potentially life-threatening hemodynamic events, such as severe hypovolemia due to hemorrhage, or cardiac failure. The ideal monitoring device does not exist, but some conditions must be met: it should be easy and operator-independently to use; it should provide adequate, reproducible information in real time. In this review we discuss in particular the role of intraoperative use of transesophageal echocardiography (TOE). Although TOE has gained special relevance in cardiac surgery, its role in major non cardiac surgery is still to be determined. We particularly focus on its ability to provide measurements of cardiac output (CO), and its role to guide fluid therapy. Within the last decade, concepts oriented on optimizing stroke volume and cardiac output mainly by fluid administration and guided by continuous monitoring of cardiac output or so called functional parameters of cardiac preload gained particular attention. Although they are potentially linked to an increased amount of fluid infusion, recent data give evidence that such pre-emptive concepts of hemodynamic optimization result in a decrease in morbidity and mortality. As TOE allows a real time direct visualization of cardiac structures, other potentially important advantages of its use also outside the cardiac surgery operation room can be postulated, namely the ability to evaluate the anatomical and functional integrity of the left and the right heart chambers. Finally, a practical approach to TOE monitoring is presented, based on a local experience.

Tumescent liposuction: partitioning of lidocaine at a lower dose (252 mg/l)

BACKGROUND

The popularity of large-volume liposuction and the toxicity of lidocaine have led to a reduction of lidocaine dosage in tumescent liposuction. We have gradually reduced the concentration of lidocaine from 500 to 252 mg/l over the past decade.

OBJECTIVE

To evaluate the partitioning and the recovery of lidocaine at a lower concentration in tumescent liposuction.

METHODS

10 consecutive patients' aspirate samples were analysed for the lidocaine concentration in the fat and the fluid component, the percentage of injected lidocaine removed by aspiration and its partition coefficient in fat versus fluid.

RESULTS

7.5% of the injected lidocaine was removed; its partition coefficient was 0.21.

CONCLUSION

7.5% of the total lidocaine was aspirated in tumescent liposuction. The fat uptake of lidocaine was lower than in previous reports, which was of particular interest for future studies on lidocaine toxicity for the safety of the patients undergoing tumescent liposuction.