Journal of clinical monitoring and computing
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J Clin Monit Comput · Feb 2009
Technical performance and reflection capacity of the anaesthetic conserving device--a bench study with isoflurane and sevoflurane.
The anaesthetic conserving device (AnaConDa), Sedana Medical, Sundbyberg, Sweden) facilitates administration of isoflurane or sevoflurane by liquid infusion. An anaesthetic reflector inside the device conserves exhaled anaesthetic and re-supplies it during inspiration. In this bench study, we examined the influence of infusion rates and ventilatory settings on the resulting anaesthetic concentrations on patient (C(pat)) and ventilator side of the reflector (C(loss)) to describe its technical performance. ⋯ The triple product minute volume times R(C) times C(pat) describes anaesthetic losses through the reflector. It can easily be calculated as long as the 10 ml reflection capacity is not exceeded and thus R(C) is constant. Increased minute ventilation necessitates increasing the IR to keep C(pat) constant. When using large V(T) and high C(pat) "spill over" occurs. This effect offers some protection against an inadvertent overdose.
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J Clin Monit Comput · Dec 2008
Case ReportsMainstream time-capnography: an aid to select an appropriate uncuffed endotracheal tube in small children.
Uncuffed endotracheal tubes are commonly used in children in an attempt to decrease the potential for pressure induced tracheal injury. However, uncuffed endotracheal tube may increase the risk of aspiration and lead to erratic delivery of preset tidal volume during mechanical ventilation. ⋯ Air-leak following tracheal intubation can be recognized by the presence of audible leak, by auscultation over the trachea, by palpation over the trachea and by observing effects of positive end-expiratory pressure on inspiratory expiratory tidal volume difference during mechanical ventilation. We describe mainstream time-capnograph as an aid to recognize leak around the endotracheal tube and its utility to determine appropriate endotracheal tube size in small children.
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J Clin Monit Comput · Dec 2008
Is the cardiac output obtained from a Swan-Ganz catheter always zero?
By means of a Swan-Ganz catheter cardiac output is calculated using the Stewart-Hamilton thermodilution equation. Assuming the body as a thermally isolated inert system, this equation theoretically always results in zero cardiac output. ⋯ It is at least a necessary condition for the application of the Stewart-Hamilton equation, that core body temperature is kept constant in a thermo- regulatory steady state.
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J Clin Monit Comput · Oct 2008
Controlled Clinical TrialTransoesophageal Doppler monitoring for fluid and hemodynamic treatment during lung surgery.
Patients undergoing lung resection are vulnerable to fluid overhydration. Recently, goal-directed fluid therapy using transoesophageal Doppler monitoring (TDM) has been shown to improve postoperative clinical outcome. The aim of this study was to assess the feasibility of TDM during open-chest procedures for guiding fluid and hemodynamic treatment. ⋯ In thoracic surgical patients, TDM can be used to detect and correct low flow conditions and to guide hemodynamic support during the intraoperative period.
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J Clin Monit Comput · Oct 2008
Reliability of cardiac output calculation by the fick principle and central venous oxygen saturation in emergency conditions.
For many years thermodilution has been the gold standard for determining cardiac output in the critically ill patients. Less invasive methods have recently been introduced. This study aimed at evaluating the agreement between cardiac output (CO) measured by a new Fick method, using central venous saturation (Scvo(2)), and that measured by the classic thermodilution technique, in patients requiring emergent CO evaluation. ⋯ The new method of Fick assessed emergent CO as reliably as the thermodilution, regardless of whether it was low or high. The use of Scvo(2) allows for prompt bedside calculation for most emergency patients.