Anaesthesia
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We compared the work needed to retract a non-lubricated and a lubricated stylet from a tracheal tube over 24 h. Stylets were lubricated with sterile water, silicone fluid, lidocaine spray, lidocaine gel, MedPro(®) lubricating gel or Lacri-Lube(®). ⋯ Where a tracheal tube is pre-loaded with a stylet for use at an indeterminate time, silicone fluid was the best choice of lubricant as it performed consistently well up to 24 h. At 24 h only silicone fluid (0.49 (0.01)) outperformed no lubrication (0.77 (0.24); p = 0.04).
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Movement and haemodynamic responses to noxious stimuli during general anaesthesia are regarded as signs of nociception. We compared the Nociceptive Flexion Reflex Threshold (NFRT), Bispectral Index (BIS), Composite Variability Index (CVI), Noxious Stimulation Response Index (NSRI) and the calculated propofol/remifentanil effect-compartment concentrations (Ce) as predictors for such responses in 50 female subjects at laryngeal mask airway insertion and skin incision. The following prediction probabilities (PK-values) were obtained at laryngeal mask airway insertion and skin incision, respectively. ⋯ For heart rate responses: NFRT = 0.68 and 0.75, p = 0.04 and 0.01, respectively; BIS = 0.37 and 0.59, p = 0.15 and 0.41, respectively; CVI = 0.41 and 0.44, p = 0.39 and 0.37, respectively; NSRI = 0.48 and 0.53, p = 0.84 and 0.78, respectively; propofol-Ce = 0.42 and 0.56, p = 0.39 and 0.53, respectively; remifentanil-Ce = 0.58 and 0.54, p = 0.35 and 0.73, respectively. We conclude that the NFRT best predicts movement and heart rate responses to noxious stimuli. Effect-compartment concentrations and NSRI also predict movement (but not heart rate) responses satisfactorily.
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Anaphylaxis is a life-threatening emergency that may necessitate admission to a critical care unit. There are no reports of the frequency of admission to critical care units for patients with anaphylaxis or indeed any description of their demographic characteristics or outcomes. We analysed all physician-diagnosed cases of anaphylaxis over a 5-year period in national audit data from critical care units across the UK. ⋯ The number of admissions has risen in both children and adults. Although admission ratios between the sexes were comparable in children, there was a female preponderance in adult life. Survival rates were high at over 90%.
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We report laboratory and clinical evaluations of a blood propofol concentration analyser. Laboratory experiments used volunteer blood spiked with known propofol concentrations over the clinically relevant concentrations from 0.5 to 16 μg.ml(-1) to assess linearity and the influence of haematocrit and concurrent drug administration. Analyser concentrations demonstrated excellent linearity (R(2) = 0.999). ⋯ Clinical performance of the analyser was assessed using 80 arterial blood samples from 72 patients receiving propofol infusions during cardiac surgery. Samples were processed using the propofol analyser, and high performance liquid chromatography (HPLC) used as a gold-standard comparator. These data demonstrated excellent agreement between the propofol analyser and HPLC with a bias of 0.13 μg.ml(-1) and precision of -0.16 to 0.42 μg.ml(-1).