Cardiovascular changes during laparoscopy

Abstract

There have been several reports of cardiac output measurements during laparoscopy for gynaecological purposes, using dye dilution techniques. Techniques for measuring cardiac output which involve arterial and central venous cannulation did not seem appropriate to us in healthy patients undergoing a relatively minor surgical procedure. It was therefore decided to measure cardiac output during laparoscopy using a Minnesota Impedance C a r d i~g r a p h .~-~ This is a non-invasive technique which enables repeated measurements to be made at short time intervals. The values of stroke volume produced correlate satisfactorily with other methods currently and, in particular, with electromagnetic flowmeters' which also measure stroke volume on a beat by beat basis. Impedance cardiographyThis technique is based on the observation that if an alternating current is passed across the thorax it is possible to demonstrate that there is a change of electrical impedance with each cardiac cycle. A constant sinusoidal alternating current of 4 mA RMS at 100 kHz is passed between electrodes 1 and 4 and the transthoracic impedance is measured between the inner two electrodes 2 and 3 (Fig. I). These impedance changes with each cardiac cycle (Az) are differentiated to produce the trace - (Fig. 2).The peak of this trace represents the maximum rate of change of electrical impedance

The duration of hemodynamic depression during laparoscopic cholecystectomy

“…Fortunately, despite rather signi®cant hemodynamic depression associated with laparoscopy, clinical complications related to these eects are rare [3,6,17]. Several authors have reported consistent decreases in CI related to pneumoperitoneum [2,3,7,9,12]. Many of these have been as great as 30%.…”

“…The adverse hemodynamic eects of the pneumoperitoneum during laparoscopic cholecystectomy (LC) have been well documented [2,4,9,11]. Initial studies of pneumoperitoneum were carried out in young women undergoing brief gynecologic procedures and hemodynamic eects were modest [2,8].…”

The effects of pneumoperitoneum and patient position on hemodynamics during laparoscopic cholecystectomy

“…Pneumoperitoneum has consistently been shown to increase mean arterial pressure, heart rate, and central venous pressure [3,4]. Decreases in cardiac output as great as 30% have been reported as well; however, most of these studies were conducted in young healthy women undergoing brief gynecologic procedures [2,7,11,12].…”

Myocardial Hemodynamic and Metabolic Changes during Abdominal Insufflation with Carbon Dioxide

“…Lenz et al [9] established a correlation between cardiac depression and the amount of abdominal carbon dioxide used. It was also stated that the 15 mm Hg abdominal carbon dioxide pressure results in elevated MAP, SVR and reduced stroke volume [9]. Stroke volume reduction is the result of a combination of a depressant effect of carbon dioxide on myocardial contractility and the rise in afterload.…”