Journal of clinical monitoring and computing
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J Clin Monit Comput · Oct 2013
Randomized Controlled TrialRespiratory parameters as a surrogate marker for duration of intubation: potential application of automated vital sign collection.
Prolonged time during endotracheal tube placement has been associated with poor outcomes, including cardiac arrest and death. For this reason, the accurate measurement of the duration of intubation time is an important metric in studies that evaluate interventions to improve airway outcomes. In the current study we correlated the gaps in routinely measured ventilatory parameters with duration of the intubation procedure to determine if these intervals could be used to accurately calculate the intubation time. ⋯ The gap in measured tidal volume of 39 ± 53 s most closely approximated the actual duration of intubation of 38 ± 28 s, (R(2) = 0.85, y = x - 0.87). During intubation, the disappearance gaps in tidal volume, and the airway pressure and flow waveforms highly correlate with the duration of the intubation procedure and may be useful in the evaluation of airway management interventions. However, just as there are limitations to a labor-intensive method of recording airway management timing, there are limitations to using an automated method.
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J Clin Monit Comput · Oct 2013
Case ReportsErroneous continuous cardiac output by calibrated pulse contour analysis.
Pulse contour analysis techniques are used for beat-to-beat tracking of cardiac output in critically ill patients. However, an adequate pulse pressure waveform signal and identification of the appropriate (i.e. systolic) part of the waveform by the monitor are crucial for correct calculation of continuous cardiac output. ⋯ We would like to emphasize the importance of visually checking the waveform for any irregularities that may cause erroneous calculations before initiating a therapy based on these values. One advantage of the system used here is that the part of the pressure curve used for analysis is automatically indicated.
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J Clin Monit Comput · Oct 2013
Clinical TrialMonitoring nociception during general anesthesia with cardiorespiratory coherence.
A novel wavelet transform cardiorespiratory coherence (WTCRC) algorithm has been developed to measure the autonomic state. WTCRC may be used as a nociception index, ranging from 0 (no nociception, strong coherence) to 100 (strong nociception, low coherence). The aim of this study is to estimate the sensitivity of the algorithm to nociception (dental dam insertions) and antinociception (bolus doses of anesthetic drugs). ⋯ A bolus dose of anesthetics changed the WTCRC by -15 (-50 %) [-21 to -9.3], HRmean by -4.8 beats/min (4.6 %) [-6.6 to -2.9], and NIBPmean by -2.6 mmHg (3.4 %) [-4.7 to -0.50]. A nociception index based on cardiorespiratory coherence is more sensitive to nociception and antinociception than are HRmean or NIBPmean. The WTCRC algorithm shows promise for noninvasively monitoring nociception during general anesthesia.
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J Clin Monit Comput · Oct 2013
Case ReportsAssessment and confirmation of tracheal intubation when capnography fails: a novel use for an USB camera.
A 62 year old male with a right pyriform fossa lesion extending to the right arytenoid and obscuring the glottic inlet was planned for laser assisted excision. Direct laryngoscopic assessment after topicalization of the airway, showed a Cormack Lehane grade 3 view. ⋯ Capnography may not be reliable as a sole indicator of confirmation of correct endotracheal tube placement. Video laryngoscopy may provide additional confirmation of endotracheal intubation.
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J Clin Monit Comput · Oct 2013
Heart rate variability indices for very short-term (30 beat) analysis. Part 2: validation.
Heart rate variability (HRV) analysis over shorter periods may be useful for monitoring dynamic changes in autonomic nervous system activity where steady-state conditions are not maintained (e.g. during drug administration, or the start or end of exercise). This study undertakes a validation of 70 HRV indices that have previously been identified as possible for short-term use. The indices were validated over 10 × 30 beat windows using PhysioNet databases with physiological states of rest, active, exercising, sleeping, and meditating (N from 12 to 20). ⋯ Spectral indices using the Lomb-Scargle algorithm were able to correctly identify paradoxical shifts in power with meditation and reduced power in exercise. Some less-known indices gave interesting results: PolVar20 identified the higher sympathetic activity of exercise with the largest positive magnitude. These indices should now be considered for rigorous gold standard tests with pharmacological blockade.