Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2017
Can intracranial pressure be measured non-invasively bedside using a two-depth Doppler-technique?
Measurement of intracranial pressure (ICP) is necessary in many neurological and neurosurgical diseases. To avoid lumbar puncture or intracranial ICP probes, non-invasive ICP techniques are becoming popular. A recently developed technology uses two-depth Doppler to compare arterial pulsations in the intra- and extra-cranial segments of the ophthalmic artery for non-invasive estimation of ICP. ⋯ The correlation between invasive and non-invasive ICP measurements was good (R = 0.74), and the 95 % limits of agreements were -1.4 ± 8.8 mmHg. The within-patient correlation varied between 0.47 and 1.00. This non-invasive technique is promising, and these results encourage further development and evaluation before the method can be recommended for use in clinical practice.
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This paper addresses the problem of patient model synthesis in anesthesia. Recent advanced drug infusion mechanisms use a patient model to establish the proper drug dose. However, due to the inherent complexity and variability of the patient dynamics, difficulty obtaining a good model is high. ⋯ Then, an adaptive strategy that uses genetic algorithms is implemented. The validation of the modeling technique was done using real data obtained from real patients in the operating room. Results show that the proposed method based on artificial intelligence appears to be an improved alternative to existing compartmental methodologies.
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J Clin Monit Comput · Apr 2017
Comparative StudyEstimated continuous cardiac output based on pulse wave transit time in off-pump coronary artery bypass grafting: a comparison with transpulmonary thermodilution.
To evaluate the accuracy of estimated continuous cardiac output (esCCO) based on pulse wave transit time in comparison with cardiac output (CO) assessed by transpulmonary thermodilution (TPTD) in off-pump coronary artery bypass grafting (OPCAB). We calibrated the esCCO system with non-invasive (Part 1) and invasive (Part 2) blood pressure and compared with TPTD measurements. We performed parallel measurements of CO with both techniques and assessed the accuracy and precision of individual CO values and agreement of trends of changes perioperatively (Part 1) and postoperatively (Part 2). ⋯ During OPCAB, esCCO demonstrated poor accuracy, precision and trending ability compared to TPTD. Postoperatively, non-invasive esCCO showed better agreement with TPTD. However, invasive calibration of esCCO did not improve the accuracy and precision and the trending ability of method.
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J Clin Monit Comput · Apr 2017
Case ReportsFalsely low values of oxygen saturation measured by pulse oximetry in a boy treated with Chinese herb tea.
An 8-year-old boy suffering from progressive glioblastoma was scheduled for neurosurgery. Prior to induction of anaesthesia pulse oximetry measured 64 % saturation of oxygen (SpO2). Arterial blood gas analysis revealed normal oxygen saturation and normal oxygen partial pressure. ⋯ Blood samples were taken and analysed. Absorption spectroscopy from the patient's blood showed an uncommon absorption maximum at 684 nm besides the normal maxima. The normalisation of SpO2 values after stopping Chinese herb tea administration leads to the conclusion that one of its ingredients caused the distorted pulse oximetry measurement.
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J Clin Monit Comput · Apr 2017
Hypoxic events and concomitant factors in preterm infants on non-invasive ventilation.
Automated control of inspired oxygen for newborn infants is an emerging technology, currently limited by reliance on a single input signal (oxygen saturation, SpO2). This is while other signals that may herald the onset of hypoxic events or identify spurious hypoxia are not usually utilised. We wished to assess the frequency of apnoea, loss of circuit pressure and/or motion artefact in proximity to hypoxic events in preterm infants on non-invasive ventilation. ⋯ Hypoxic events are frequently accompanied by respiratory pauses and/or motion artefact. Real-time monitoring and input of respiratory waveform may thus improve the function of automated oxygen controllers, allowing pre-emptive responses to respiratory pauses. Furthermore, use of motion-resistant oximeters and plethysmographic waveform assessment procedures will help to optimise feedback control of inspired oxygen delivery.