Journal of clinical monitoring and computing
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J Clin Monit Comput · Aug 2020
Intracranial pressure variability: relation to clinical outcome, intracranial pressure-volume index, cerebrovascular reactivity and blood pressure variability.
It was recently found in traumatic brain injury (TBI) that ICP variability (ICPV) predicted favorable outcome. We hypothesized that ICPV may depend on intracranial compliance, unstable blood pressure and cerebral vasomotion. In this study, we aimed to further investigate the explanatory variables for ICPV and its relation to outcome. ⋯ All ICPV measures were associated with favorable outcome in univariate analysis, but only ICP AMP 55-15 and ICPV-30m did so in the multiple logistic regression analysis. Higher ICPV can be explained by a reduced intracranial compliance and variations in cerebral blood volume due to the vessel response to unstable blood pressure. As ICP AMP 55-15 and ICPV-30m independently predicted favorable outcome, it may represent general cerebral vessel activity, associated with better cerebral blood flow regulation and less secondary insults.
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J Clin Monit Comput · Aug 2020
Facing SpO2 and SaO2 discrepancies in ICU patients: is the perfusion index helpful?
Peripheral oxygen saturation (SpO2) measured by pulse oximetry is an unreliable surrogate marker for arterial oxygenation (SaO2) in critically ill patients. We hypothesized that a higher perfusion index (PFI) would be associated with better accuracy of SpO2 measurement. We retrospectively collected SaO2, SpO2, and PFI data for each arterial blood gas (ABG) analysis in a cohort of intensive care unit patients. ⋯ The accuracy of pulse oximetry for estimating arterial oxygenation was moderate and improved little with increasing PFI values. Thus, the additive value of PFI in clinical decision making is limited. Therefore, we advise performing an ABG before adjusting fraction of inspired oxygen (FiO2) settings.
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J Clin Monit Comput · Aug 2020
Comparative StudyA comparison of controlled ventilation with a noninvasive ventilator versus traditional mask ventilation.
After induction, but before intubation, many general anesthesia patients are manually bag-mask ventilated. The objective of this study was to determine the efficacy of bag-mask ventilation (MkV) of an anesthetized patient versus mask ventilation using a noninvasive ventilator (NIV). We hypothesized that feedback-controlled, mask ventilation via NIV is more efficacious and safer. ⋯ It can deliver more optimal tidal volumes with the operator utilizing only one hand. The airway pressures are fixed at safe limits during a period where the goal is to reach a maximal level of oxygenation prior to intubation. Over-ventilation or over-pressurization of the airway is not a concern with NIV since the pressures are maintained well within safe thresholds to avoid injury.
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J Clin Monit Comput · Aug 2020
A novel method for transpulmonary pressure estimation using fluctuation of central venous pressure.
The objective of the study is to develop a correction method for estimating the change in pleural pressure (ΔPpl) and plateau transpulmonary pressure (PL) by using the change in central venous pressure (ΔCVP). Seven children (aged < 15 years) with acute respiratory failure (PaO2/FIO2 < 300 mmHg), who were paralyzed and mechanically ventilated with a PEEP of < 10 cmH2O and had central venous catheters and esophageal balloon catheters placed for clinical purposes, were enrolled prospectively. ⋯ The plateau PL calculated using the cΔCVP-derived ΔPpl (17.6 ± 2.6 cmH2O) correlated well with the ΔPes-derived plateau PL (18.1 ± 2.3 cmH2O) (R2 = 0.90, p = 0.001). Our correction method can estimate ΔPpl and plateau PL from ΔCVP with a reasonable accuracy in paralyzed and mechanically ventilated pediatric patients with respiratory failure.