Journal of clinical monitoring and computing
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J Clin Monit Comput · Aug 2011
Pharmacodynamic modeling of propofol-induced tidal volume depression in children.
This investigation aimed to develop a pediatric pharmacodynamic model of propofol-induced tidal volume depression towards an ultimate goal of developing a dosing schedule that would preserve spontaneous breathing following a loading dose of propofol. ⋯ A pediatric pharmacodynamic model of propofol-induced tidal volume depression was developed. Models derived from 3 different approaches were shown to be consistent with each other; however, the individual pharmacodynamic parameters exhibited significant inter-individual variability without strong dependence on age and body weight. This would suggest the desirability of adapting the pharmacodynamic model to each subject in real time.
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J Clin Monit Comput · Aug 2011
Perioperative metabolic alkalemia is more frequent than metabolic acidemia in major elective abdominal surgery.
To investigate the incidence, type and etiology of perioperative metabolic disturbances associated with major abdominal surgery. We hypothesized that metabolic alkalemia is more frequent than metabolic acidemia. ⋯ Metabolic alkalemia occurred more frequently than metabolic acidemia and occurred mainly preoperatively and postoperatively, while acidemia occurred mainly during surgery and in the PACU.
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The pleth variability index (PVI), which is calculated from respiratory variations in the perfusion index (PI), reportedly predicts fluid responsiveness. However, vasomotor tone fluctuations induced by nociceptive stimuli change the PI and may reduce the accuracy of PVI. The aim of this study was to confirm the effects of surgical stimuli on PVI. ⋯ This study showed a significant increase in the PVI and a negative correlation between the changes in PVI and PI before and after the skin incision. The PVI can be calculated from the variations in the PI caused not by mechanical ventilation, but rather by fluctuations in vasomotor tone. When using the PVI as an indicator for fluid responsiveness, it is crucial to pay attention to fluctuations in vasomotor tone induced by nociceptive stimuli.
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J Clin Monit Comput · Aug 2011
The impact of induction of general anesthesia and a vascular occlusion test on tissue oxygen saturation derived parameters in high-risk surgical patients.
Tissue oxygen saturation (StO(2)) assessed using Near Infrared Spectroscopy and its derived parameters during a vascular occlusion test (VOT) can detect microvascular changes in septic shock patients. General anesthesia (GA) impacts microcirculation. Our aim was to study the effects of general anesthesia on StO(2) and StO(2) derived parameters obtained during VOT in patients referred for cardiac surgery. ⋯ StO(2) derived parameters during a VOT are impacted by GA induction. These parameters may have potential for microcirculation assessment in patients undergoing surgery.
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J Clin Monit Comput · Aug 2011
Cardioplegia and ventricular late potentials in cardiac surgical patients.
Ventricular late potentials (LP) recording with signal-averaged electrocar- diogram allow identifying patients at risk of sudden death and ventricular tachycardia. Cardiac surgery with cardiopulmonary bypass (CPB) could predispose to the development of myocardial ischemia related to imperfect cardioplegia. To the best of our knowledge, no study investigated the protection of cardioplegia and CPB regarding the occurrence of LP in patients without previous myocardial infarction and undergoing cardiac surgery. ⋯ The present study in cardiac surgical patients suggests that cardioplegia associated to CPB has no significant impact on the occurrence of LP, irrespective of surgery performed.