Anaesthesia and intensive care
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Anaesth Intensive Care · Jan 2010
Randomized Controlled TrialThe Entropy Module and Bispectral Index as guidance for propofol-remifentanil anaesthesia in combination with regional anaesthesia compared with a standard clinical practice group.
This study was designed to investigate the impact of the Entropy Module and Bispectral Index (BIS) monitoring on drug consumption and recovery times compared with standard anaesthetic practice in patients undergoing orthopaedic surgery using a combination of regional and general anaesthesia as performed by an experienced anaesthesiologist. We hypothesised that electroencephalogram monitoring would lead to a lower drug consumption as well as shorter recovery times. With institutional review board approval and written informed consent, 90 adult patients undergoing surgery to the upper or lower extremity received regional anaesthesia for post- and intraoperative pain control and were randomised to receive general anaesthesia by propofol/remifentanil infusion controlled either solely by clinical parameters or by targeting Entropy or BIS values of 50. ⋯ Compared with standard practice, patients with Entropy or BIS monitoring showed a similar propofol consumption (standard practice 101 +/- 22 microg/kg/minute, Entropy 106 +/- 24 microg/kg/minute, BIS 104 +/- 20 microg/kg/minute) and showed similar Aldrete scores (10/10) one minute after extubation: 9.1 +/- 0.3, 9.2 +/- 0.6 and 9.3 +/- 0.5, respectively. Time points of extubation were 7.3 +/- 2.9 minutes, 9.2 +/- 3.9 minutes and 6.8 +/- 2.9 minutes, respectively, demonstrating a significant difference between Entropy and BIS (P = 0.023). Compared with standard practice, targeting an Entropy or BIS value of 50 did not result in a reduction of propofol consumption during general anaesthesia combined with regional anaesthesia as performed by an experienced anaesthesiologist in orthopaedic patients.
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Anaesth Intensive Care · Jan 2010
Review Meta AnalysisAn overview of evidence from systematic reviews evaluating early enteral nutrition in critically ill patients: more convincing evidence is needed.
International quality improvement initiatives such as Fast-Hug bring a focus on improving the delivery of early enteral nutrition to critically ill patients, however surveys demonstrate current practice remains variable. One way to reduce variability in practice is to provide strong evidence to convince clinicians to change. The purpose of this overview was to identify current best evidence supporting the delivery of early enteral nutrition in critical illness. ⋯ The results of this overview highlight the variability in the evidence regarding the benefits of early enteral nutrition in critically ill patient populations. The inconsistent delivery to critically ill patients may be explained by the lack of convincing evidence. Better evidence may be needed to reduce the irregularity in the provision of early enteral nutrition to critically ill patients.
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Anaesth Intensive Care · Jan 2010
Randomized Controlled TrialFentanyl dosage and timing when inserting the laryngeal mask airway.
The study objective was to show that fentanyl given five minutes prior to induction improved insertion conditions for the Classic Laryngeal Mask Airway. Previous work had shown fentanyl at 90 seconds to be unpredictable. A probit analysis design was used in which success/failure rates of different doses of fentanyl were measured and dose-response curves drawn from which the ED50 and ED95 with 95% confidence intervals were determined. ⋯ Commonly used fentanyl doses of 1 to 2 microg x kg(-1) only prevented patients responding to insertion in 70 to 80% of cases. When using propofol 2.5 mg x kg(-1), administering fentanyl five minutes before laryngeal mask insertion does not provide ideal insertion conditions in 95% of cases unless excessively large doses are used. An ideal dose of fentanyl that produces optimum insertion conditions could not be determined.
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Anaesth Intensive Care · Jan 2010
Randomized Controlled TrialFentanyl dose for the insertion of Classic Laryngeal Mask Airways in non-paralysed patients induced with propofol 2.5 mg/kg.
The aim of this randomised, controlled trial was to determine the optimum dose of fentanyl in combination with propofol 2.5 mg x kg(-1) when inserting the Classic Laryngeal Mask Airway. Seventy-five ASA I or II patients were randomly assigned to five groups of fentanyl dosage: 0 microg x kg(-1) (placebo), 0.5 microg x kg(-1), 1.0 microg x kg(-1), 1.5 microg x kg(-1) and 2.0 microg x kg(-1). Anaesthesia was induced by first injecting the study drug over 10 seconds. ⋯ We found that there was a high rate of successful first attempt at insertion with 1 microg x kg(-1) and 1.5 microg x kg(-1), 93% and 87% respectively, compared to 87% in the 2.0 microg x kg(-1) group. The 1.0 microg x kg(-1) group also achieved an 80% optimal insertion conditions score of 4, compared to 73% in the 1.5 microg x kg(-1) group and 80% in the 2 microg x kg(-1) group. Therefore we recommend 1.0 microg x kg(-1) as the optimal dose of fentanyl when used in addition to propofol 2.5 mg/kg for the insertion of the Classic Laryngeal Mask Airway.
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Anaesth Intensive Care · Jan 2010
Clinical TrialEpisodic waveforms in the electroencephalogram during general anaesthesia: a study of patterns of response to noxious stimuli.
Previous studies of the electroencephalogram (EEG) during anaesthesia have identified two distinct patterns of change in response to a noxious stimulus, a classical arousal pattern and a paradoxical arousal pattern. We developed methods of EEG analysis to quantify episodic EEG patterns--namely sleep spindle-like ('10 Hz-score') and burst-suppression-like fluctuations in high frequencies ('high frequency variation index')--and used traditional power spectral quantification of non-episodic delta waves. We studied 30 healthy adult patients undergoing elective surgery under general anaesthesia with propofol, fentanyl (1.0, 2.5 or 4.0 microg/kg, n=10 for each group), muscle relaxant and sevoflurane. ⋯ The nociception-induced reduction in spindles was greater in the low-dose fentanyl group (P = 0.01). There was less tachycardia in the high-dose fentanyl group (P = 0.002). It is possible to quantify such episodic EEG patterns during general anaesthesia and in this study noxious stimulation tended to reduce the prevalence of these patterns.