Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2019
Assessment of central hemodynamic effects of phenylephrine: an animal experiment.
Phenylephrine is an α1-adrenergic receptor agonist widely used to treat perioperative hypotension. Its other hemodynamic effects, in particular on preload and contractility, remain controversial. We, therefore, investigated the effect of continuously applied phenylephrine on central hemodynamics in eight mechanically ventilated domestic pigs. ⋯ Phenylephrine does not only affect cardiac afterload, but also increases effective preload. In contrast to CVP and Pmsfa, this effect can be monitored by GEDV. Further, phenylephrine affects contractility.
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J Clin Monit Comput · Jun 2019
Observational StudyInvestigation of intraoperative dosing patterns of neuromuscular blocking agents.
There is a growing body of literature documenting the use of deep neuromuscular block (NMB) during surgery. Traditional definitions of depth of NMB rely on train-of-four assessment, which can be less reliable in retrospective studies. The goal of our study was to investigate the real-world practice pattern of dosing of neuromuscular blocking agents (NMBA), utilizing the amount of NMBA used during the course of a case, adjusted for patient weight and case duration, as a surrogate measure of depth of NMB. ⋯ Cases with higher rates of HD may be those that are traditionally technically complex or emergent, would benefit from greater paralysis, or do not use adjunctive medications for muscle relaxation. Age greater than 65 years was shown to have lower rates of HD, likely due to provider awareness of age-related changes in pharmacokinetics and pharmacodynamics. Intraoperative monitoring and NMB antagonism with neostigmine were used more frequently with HD.
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Electronic medical records now store a wealth of intraoperative hemodynamic data. However, analysis of such data is plagued by artifacts related to the monitoring environment. Here, we present an algorithm for automated identification of artifacts and replacement using interpolation of arterial line blood pressures. ⋯ The average difference between manual review and algorithm in identifying the start of arterial line monitoring was 0.17, and 2.1 min for the end of monitoring. Application of the algorithm decreased the percent of time below 55 mmHg from 4.3 to 2.0% (2.1% with manual review) and time above 100 mmHg from 8.8 to 7.3% (7.3% manual). This algorithm's performance was comparable to manual review by a human anesthesiologist and reduced the incidence of abnormal MAP values identified using a sample analysis tool.
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J Clin Monit Comput · Jun 2019
Comparative StudyTwo different methods to assess sympathetic tone during general anesthesia lead to different findings.
Noxious stimulation influences the autonomic nervous system activity. Sympathetic tone monitoring is currently used to assess the adequacy of the balance between nociception and anti-nociception during general anesthesia. The Surgical Plethysmographic Index (SPI) and the EBMi software (Custos©) are commercial devices that use different algorithms to measure it. ⋯ Longer SPI ≥ 60 episodes were associated with lower anti-nociception anesthetic regimen. Different methods of sympathetic tone assessment during general anesthesia provide conflicting information. Prospective studies should be undertaken to clarify the clinical indications of both techniques.