Anaesthesia
-
Pain diagnosis and management would benefit from the development of objective markers of nociception and pain. Current research addressing this issue has focused on five main strategies, each with its own advantages and disadvantages. ⋯ Although each strategy has shown areas of promise, there are currently no validated objective markers of nociception or pain that can be recommended for clinical use. This article introduces the most important developments in the field and highlights shortcomings, with the aim of allowing the reader to make informed decisions about what trends to watch in the future.
-
We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in-plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. ⋯ In 10 cases, we confirmed catheter position by magnetic resonance imaging. We judged 43/45 initial placements successful and 42/43 secondary placements successful by ultrasound, confirmed in 10/10 cases by magnetic resonance imaging.
-
Observational Study
Continuous monitoring of haemoglobin concentration after in-vivo adjustment in patients undergoing surgery with blood loss.
Non-invasive monitoring of haemoglobin concentration provides real-time measurement of haemoglobin concentration (SpHb) using multi-wavelength pulse co-oximetry. We hypothesised that in-vivo adjustment using the mean of three haemoglobinometer (HemoCue®) measurements from an arterial blood sample at the first SpHb measurement (HCueART) would increase the accuracy of the monitor. The study included 41 adults for a total of 173 measurements of haemoglobin concentration. ⋯ The accuracy of in-vivo adjusted SpHb was compared with SpHb retrospectively adjusted using the same formula, except for haemoglobin level which was assessed at the central laboratory and then compared with all other available invasive methods of haemoglobin measurement (co-oximetry, HbSAT; arterial HemoCue, HCueART; capillary HemoCue, HCueCAP). Compared with laboratory measurement of haemoglobin concentration, bias (precision) for unadjusted SpHb, in-vivo adjusted SpHb, retrospectively adjusted SpHb, HbSAT, HCueART and HCueCAP were -0.4 (1.4), -0.3 (1.1), -0.3 (1.1), -0.6 (0.7), 0.0 (0.4) and -0.5 (1.2) g.dl(-1) , respectively. In-vivo adjustment of SpHb values using the mean of three arterial HemoCue measurements improved the accuracy of the device similar to those observed after a retrospective adjustment using central laboratory haemoglobin level.
-
Randomized Controlled Trial
Timing of reversal with respect to three nerve stimulator end-points from cisatracurium-induced neuromuscular block.
After elective ear surgery with cisatracurium neuromuscular blockade, 48 adults were randomly assigned to receive neostigmine: (a) at appearance of the fourth twitch of a 'train-of-four'; (b) at loss of fade to train-of-four; or (c) at loss of fade to double-burst stimulation, all monitored using a TOF-Watch SX® on one arm. For each of these conditions, the recovery from train-of-four (TOF) ratio was measured in parallel objectively using a TOF-Watch SX placed on the contralateral arm. ⋯ This recovery time was significantly shorter when reversal was given at loss of fade to double-burst stimulation (c), than when given at the appearance of the fourth twitch (a), p = 0.046. However, the total time to extubation may be unaffected as it takes longer for fade to be lost after double-burst stimulation than for four twitches subjectively to appear.
-
We compared the McGrath® Series 5 videolaryngoscope with the Macintosh laryngoscope for double-lumen tracheal tube placement in patients with a predicted good glottic view on assessment of the airway. An initial laryngoscopy was performed using the Macintosh laryngoscope; 96 patients with Cormack and Lehane grade-1 or -2a views were randomly assigned to undergo intubation using either the McGrath or Macintosh device. ⋯ However, in 18 non-randomised patients with Cormack and Lehane grade ≥ 2b on initial laryngoscopy using the Macintosh, the glottic view was improved on intubation with the McGrath videolaryngoscope, with a total success rate of double-lumen tube placement of 94.4% and mean (SD) intubation time of 50.0 (18.6) s. We recommend that in patients with a low airway risk index score requiring intubation with a double-lumen tracheal tube, the Macintosh laryngoscope is used as the first device and the McGrath videolaryngoscope is used only if this provides a poor glottic view.