Instability of quartet analyses of molecular sequence data by the maximum likelihood method: the Cetacea/Artiodactyla relationships

As laparoscopic techniques show definite advantages in terms of pain and postoperative pulmonary function, high-risk patients especially benefit from such procedures. Pathophysiological changes caused by the pneumoperitoneum can be managed with invasive monitoring and resulting therapy. The increase in systemic vascular resistance with reduction in cardiac output can be kept to a minimum using low intraabdominal pressures (8-10 mmHg) under adequate muscular relaxation. Additional peripheral vasodilators and positive inotropic medication may be necessary. As the adverse hemodynamic effects end almost instantaneously with the reduction of the intraabdominal pressure, it is allways possible to revert to an open procedure after a laparoscopic try. If ventilation can not be increased adequately to maintain isocapnia in a patient suffering from pulmonary disease, the resulting increase in paCO2 will usually be moderate. In some instances it may be necessary to prolong artificial ventilation postoperatively, until isocapnia is reached with minuteventilation as at the beginning of anaesthesia.