Journal of clinical monitoring and computing
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J Clin Monit Comput · Feb 2022
Influence of hemorrhage and subsequent fluid resuscitation on transcranial motor-evoked potentials under desflurane anesthesia in a swine model.
Hemorrhage increases the effect of propofol and could contribute to false-positive transcranial motor-evoked potential (TcMEP) responses under total intravenous anesthesia (TIVA). We investigated the influence of hemorrhage and subsequent fluid resuscitation on TcMEPs under desflurane anesthesia. ⋯ TcMEP amplitudes decrease during hemorrhage under desflurane anesthesia. This phenomenon might result from an enhanced effect of desflurane on the spinal motor pathway without increasing the desflurane concentration.
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J Clin Monit Comput · Feb 2022
Accuracy of a battery-powered portable capnometer in premature infants.
Carbon dioxide measurement is useful for confirmation of successful tracheal intubation and ensuring adequate ventilation. There are two types of CO2 detectors, i.e., single-use-only colorimetric devices and capnometers. Although portable capnometers are widely used for resuscitation, there have been no reports regarding their clinical utility in neonates. ⋯ Therefore, PetCO2 readings obtained with a battery-powered portable capnometer were likely to be underestimated. This became more pronounced with decreasing infant body weight at examination as the net difference in measurements of PaCO2 and PetCO2 was significantly positively correlated with infant body weight at examination (r = 0.451, P < 0.001). The observations presented here may be helpful in the use of battery-powered portable capnometers in neonates requiring controlled ventilation with tracheal intubation.
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J Clin Monit Comput · Feb 2022
Tetanic stimulation of the peripheral nerve augments motor evoked potentials by re-exciting spinal anterior horn cells.
Tetanic stimulation of the peripheral nerve, immediately prior to conducting transcranial electrical stimulation motor evoked potential (TES-MEP), increases MEP amplitudes in both innervated and uninnervated muscles by the stimulated peripheral nerve; this is known as the remote augmentation of MEPs. Nevertheless, the mechanisms underlying the remote augmentation of MEPs remain unclear. Although one hypothesis was that remote augmentation of MEPs results from increased motoneuronal excitability at the spinal cord level, the effect of spinal anterior horn cells has not yet been investigated. ⋯ Furthermore, F-wave persistence was significantly increased not only in the median nerve but also in the tibial nerve after tetanic stimulation of the median nerve. The increased F-wave persistence indicates an increase of re-excited motor units in spinal anterior horn cells. These results confirm the hypothesis that tetanic stimulation of the peripheral nerve may cause remote augmentation of MEPs, primarily by increasing the excitability of the anterior horn cells.
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J Clin Monit Comput · Dec 2021
Clinical TrialComparison of the Conox (qCON) and Sedline (PSI) depth of anaesthesia indices to predict the hypnotic effect during desflurane general anaesthesia with ketamine.
Comparison of two depth of anesthesia indices, qCON (Conox) and PSI (Sedline), during desflurane sedation and their sensitivity to random ketamine boluses in patients undergoing routine surgery. The performance of desflurane and ketamine on both indices was analyzed for 11 patients, and the ketamine sensitivity was compared with another group of 11 patients under sevoflurane and propofol. The MOAA/S was used to determine sedation level and pain. ⋯ However, during desflurane anesthesia the qCON index did not change significantly after ketamine administration, qCON (before = 33 (4), after = 30 (17); Wilcoxon, p = 0.89), while the PSI experienced a significant increase, PSI (before = 31(6), after = 39(16) Wilcoxon, p = 0.013). This study shows that qCON and PSI have similar performance under desflurane with good discrimination between the awake and anesthetized states. While both indices exhibited similar behavior under ketamine boluses under a sevoflurane-propofol anesthesia, the qCON index had a better performance under ketamine during desflurane anesthesia.