Journal of clinical monitoring and computing
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J Clin Monit Comput · Aug 2002
Randomized Controlled Trial Clinical TrialBiasing effect of the electromyogram on BIS: a controlled study during high-dose fentanyl induction.
A biasing effect of the electromyogram (EMG) on the Bispectral Index (BIS) may explain discrepancies in previous studies assessing BIS in the presence of neuromuscular activity. Our aims were: to evaluate variations of BIS in the presence of high EMG activity associated with muscular rigidity after administration of high-dose fentanyl; to compare muscular rigidity, as measured by the EMG variable of the BIS monitor, in patients who were administered two different dosages of fentanyl at induction of cardiac anaesthesia. ⋯ During fentanyl-induced muscular rigidity BIS recordings reflect EMG variations. When assessing BIS in the absence of neuromuscular blockade, it is necessary to evaluate the effect of EMG on BIS before making conclusions about depth of sedation. Fentanyl-induced rigidity appears to be a dose-related phenomenon which the EMG variable of BIS 3.4 is able to quantify.
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J Clin Monit Comput · Aug 2002
Clinical TrialCorrelation beween AAI-index and the BIS-index during propofol hypnosis: a clinical study.
To determine the degree of linearity and correlation between the anaesthetic depth indices BIS and AAI over a wide range of hypnotic depth using propofol. ⋯ The AAI-index correlates with the BIS-index during propofol hypnosis in the absence of surgical stimulation. Neither the BIS-index, heart rate, nor systemic blood pressure were influenced by the acoustical stimulation from the A-line monitor. Both indices decreased in relation to increasing doses of propofol, but the AAI-index was lower both before becoming unconscious, during transition to unconsciousness, and during the deeper levels of sedation. The AAI-index lacks linearity at both very low and higher levels of propofol sedation with a nearly on-off behaviour for wakefulness vs hypnosis.
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J Clin Monit Comput · Aug 2002
Closed-loop control if the inspired fraction of oxygen in mechanical ventilation.
Supplemental oxygen treatment of patients on mechanical ventilation is crucial in maintaining the patients' oxygen levels in the normal range. The purpose of this study was to evaluate the effectiveness of a closed-loop controller for automatic adjustment of the fraction of inspired oxygen, FIO2. More specifically, the aim of the study was to assess the robustness of the controller in correcting hypoxemia as well as its effectiveness in prevention of hyperoxemia and oxygen toxicity. ⋯ The results of the study attest to the reliability of the proposed closed-loop control scheme for automatic adjustment of FIO2. Further evaluation of the controller will require testing the effectiveness of the system on different patient groups.
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J Clin Monit Comput · Aug 2002
Clinical TrialA better landmark for positioning a central venous catheter.
Improper positioning of central venous catheters (CVCs) can lead to erosion through the superior vena cava (SVC) or right atrium (RA) and pericardial tamponade. It is widely recommended that the tip of CVCs be placed above the heart or the pericardial reflection. The purpose of this study was to identify an easily recognized landmark to allow identification of the proximal extent of the pericardial reflection on a routine chest radiograph (CXR). ⋯ The distal half of the SVC lies within the pericardial reflection, and the upper limit of the pericardial reflection is slightly above the level of the carina. These landmarks are useful for determining proper position of the tip of a CVC on CXR.
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J Clin Monit Comput · Aug 2002
Computerize anesthesia record keeping in thoracic surgery--suitability of electronic anesthesia records in evaluating predictors for hypoxemia during one-lung ventilation.
The aim of this retrospective study was to assess the suitability of routine data gathered with a computerized anesthesia record keeping system in investigating predictors for intraoperative hypoxemia (SpO2 < 90%) during one-lung ventilation (OLV) in pulmonary surgery. ⋯ In contrast to conventional performed retrospective studies, data were directly available for analyses without any manual intervention. Due to incomplete information and imprecise definitions of parameters, data of computerized anesthesia records collected in routine are helpful but not satisfactory in evaluating risk factors for hypoxemia during OLV.