Journal of clinical monitoring and computing
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J Clin Monit Comput · Oct 2017
Impact of microcirculatory video quality on the evaluation of sublingual microcirculation in critically ill patients.
We aimed to assess the impact of image quality on microcirculatory evaluation with sidestream dark-field (SDF) videomicroscopy in critically ill patients and explore factors associated with low video quality. This was a retrospective analysis of a single-centre prospective observational study. Videos of the sublingual microcirculation were recorded using SDF videomicroscopy in 100 adult patients within 12 h from admittance to the intensive care unit and every 24 h until discharge/death. ⋯ Perfused vessel density was higher in patients with Glasgow Coma Scale (GCS) ≤8 (18.9 ± 4.5 vs. 17.0 ± 3.9 mm/mm2 in those with GCS >8, p < 0.001) or requiring mechanical ventilation (18.0 ± 4.5 vs. 17.2 ± 3.8 mm/mm2 in not mechanically ventilated patients, p = 0.059). We concluded that SDF video quality depends on both the operator's experience and patient's cooperation. Low-quality videos may produce spurious data, leading to an overestimation of microvascular alterations.
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J Clin Monit Comput · Oct 2017
Determination of saturation, heart rate, and respiratory rate at forearm using a Nellcor™ forehead SpO2-saturation sensor.
Alterations in arterial blood oxygen saturation, heart rate (HR), and respiratory rate (RR) are strongly associated with intra-hospital cardiac arrests and resuscitations. A wireless, easy-to-use, and comfortable method for monitoring these important clinical signs would be highly useful. We investigated whether the Nellcor™ OxiMask MAX-FAST forehead sensor could provide data for vital sign measurements when located at the distal forearm instead of its intended location at the forehead to provide improved comfortability and easy placement. ⋯ For HR measurements, the mean difference was 0.6 bpm (SD, 2.5), r = 0.997, and RMSE = 1.8. For RR, the mean difference was -0.5 1/min (4.1), r = 0.586, and RMSE = 4.0. The SpO2 readings showed a low mean difference, but also a low correlation and high RMSE, indicating that the Nellcor™ saturation sensor cannot reliably assess oxygen saturation at the forearm when compared to finger PPG measurements.
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J Clin Monit Comput · Oct 2017
Frequency-domain vs continuous-wave near-infrared spectroscopy devices: a comparison of clinically viable monitors in controlled hypoxia.
The Near-infrared spectroscopy (NIRS) has not been adopted as a mainstream monitoring modality in acute neurosurgical care due to concerns about its reliability and consistency. However, improvements in NIRS parameter recovery techniques are now available that may improve the quantitative accuracy of NIRS for this clinical context. Therefore, the aim of this study was to compare the abilities of a continuous-wave (CW) NIRS device with a similarly clinically viable NIRS device utilising a frequency-domain (FD) parameter recovery technique in detecting changes in cerebral tissue saturation during stepwise increases of experimentally induced hypoxia. ⋯ No significant difference was observed between the saturation changes observed by either device (P = 0.625). An observably greater degree of noise was noticed in parameters recovered by the FD device, and both demonstrated equally variable baseline readings (Coefficient of variance 8.4 and 9.7 % for the CW and FD devices, respectively) between individuals tested. No advantageous difference was observed in parameters recovered from the FD device compared with those detected by CW.
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J Clin Monit Comput · Oct 2017
Efficacy and safety of novel high-frequency multi-train stimulation for recording transcranial motor evoked potentials in a rat model.
Recently, low-frequency multi-train stimulation (MTS) was shown to effectively enhance transcranial motor-evoked potentials (TcMEPs). In contrast, high- frequency double-train stimulation was reported to elicit a marked facilitation. The aim of this study was to evaluate the efficacy of high-frequency MTS in the augmentation of potentials. ⋯ The aversion index was >0.8 in all animals after they received 100 high-frequency MTSs. Histologically, no pathological changes were evident in the rat brains. High-frequency MTS shows potential to effectively enhance TcMEP responses, and to be used safely in transcranial brain stimulation.
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J Clin Monit Comput · Oct 2017
ReviewThe use of the oesophageal Doppler in perioperative medicine: new opportunities in research and clinical practice.
The oesophageal Doppler (OD) is a minimally invasive haemodynamic monitor used in the surgical theatre and the ICU. Using the OD, goal-directed therapy (GDT) has been shown to reduce perioperative complications in high-risk surgical patients. However, most GDT protocols currently in use are limited to stroke volume optimisation. ⋯ Furthermore, OD-derived indexes of blood flow velocity and acceleration, as well as force and kinetic energy, can be derived and used for continuous assessment of cardiac contractility at the bedside. Using OD-derived parameters, the different components of afterload: inertia, resistance and elastance, could also be individually determined. The integration of these additional haemodynamic parameters could assist the clinician in optimising and individualising haemodynamic performance in unstable patients.