Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2021
A systematic review of invasive, high-fidelity pressure studies documenting the amplification of blood pressure from the aorta to the brachial and radial arteries.
It is commonly accepted that systolic blood pressure (SBP) is significantly higher in the brachial/radial artery than in the aorta while mean (MBP) and diastolic (DBP) pressures remain unchanged. This may have implications for outcome studies and for non-invasive devices calibration. We performed a systematic review of invasive high-fidelity pressure studies documenting BP in the aorta and brachial/radial artery. ⋯ Further studies on SPAmp phenotypes (positive, null, negative) are advocated. Non-invasive device calibration assumptions were confirmed, namely unchanged MBP and DBP from the aorta to the brachial artery. Data did not allow for firm conclusions on the amount of BP changes from the aorta to the radial artery, and from the aorta to the brachial/radial arteries in other populations.
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J Clin Monit Comput · Dec 2021
Letter Case ReportsLoss of spectral alpha power during spine surgery: what could be wrong?
The electroencephalographic signatures of anesthetic drugs relate to a specific set of action mechanisms within the neural circuits. During intraoperative care, the recognition and correct interpretation of the EEG spectrogram can be used as a tool to guide anesthetic administration. For example, loss of alpha power during propofol anesthesia may be a sign of lighter level of hypnosis and/or of an increase in nociceptive inputs. We describe a case report of inadvertent interruption of propofol delivery that was first detected by changes in the electroencephalogram spectrogram.
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J Clin Monit Comput · Dec 2021
Feasibility study of a smartphone pupillometer and evaluation of its accuracy.
Measurement of pupillary characteristics, such as pupillary unrest in ambient light, and reflex dilation have been shown to be useful in a variety of clinical situations. Dedicated pupillometers typically capture images in the near-infrared to allow imaging in both light and darkness. However, because a subset of pupillary measurements can be acquired with levels of visible light suitable for conventional cameras, it is theoretically possible to capture data using general purpose cameras and computing devices such as those found on smartphones. ⋯ In 77% of the scans the software was able to successfully identify the pupil and iris. The raw data as well as calculated values of pupillary unrest in ambient light were in clinically acceptable levels of agreement; Bland-Altman analysis of raw pupil measurements yielded a 95% confidence interval of 0.26 mm. In certain situations a smartphone pupillometer may be an appropriate alternative to a commercial pupillometer.
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J Clin Monit Comput · Dec 2021
Non-linear regression analysis for estimating the intraoperative motor evoked potential recovery time after bolus neuromuscular blockade.
The recovery time of the motor evoked potential (MEP) amplitude following a neuromuscular blockade (NMB) during surgery is useful for interpreting low-amplitude waveforms or selecting the baseline waveform. In this study, the MEP data of 195 orthopedic cases who received a bolus dose of rocuronium at the beginning of surgery, between June 2009 and January 2016 were used. A non-linear regression analysis was applied to MEP amplitude data of multiple patients. ⋯ The 90% amplitude recovery time was 88.6 min in the pharmacological model and 89.4 min in the logistic model. These results were included in the 95% confidence interval of the previous studies. Although MEP amplitude is relatively unstable because of anesthesia, the averaged time series model of MEP amplitude can be estimated by using a large number of data.
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Awake fibreoptic intubation has always been considered the gold standard for expected difficult airway management. However, the use of fibreoptic intubation was limited because it is time-consuming, requires skillful operators and easily affected by blood or secretions in the oral or nasopharynx. We reported a modified technique of awake fibreoptic nasal intubation with the aid of End-tidal carbon dioxide (ETCO2) monitoring, aiming to improve the efficiency and safety of awake fibreoptic intubation.