Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2019
Outcome impact of hemodynamic and depth of anesthesia monitoring during major cancer surgery: a before-after study.
Hemodynamic and depth of anesthesia (DOA) monitoring are used in many high-risk surgical patients without well-defined indications and objectives. We implemented monitoring guidelines to rationalize hemodynamic and anesthesia management during major cancer surgery. In early 2014, we developed guidelines with specific targets (Mean arterial pressure > 65 mmHg, stroke volume variation < 12%, cardiac index > 2.5 l min-1 m-2, central venous oxygen saturation > 70%, 40 < bispectral index < 60) for open abdominal cancer surgeries > 2 h. ⋯ Intraoperative fluid volumes decreased (16.0 vs. 14.5 ml kg-1 h-1, p = 0.002), whereas the use of inotropes increased (6 vs. 11%, p = 0.022). Postoperative delirium (16 vs. 8%, p = 0.005), urinary tract infections (6 vs. 2%, p = 0.012) and median hospital length of stay (9.6 vs. 8.8 days, p = 0.032) decreased. In patients undergoing major open abdominal surgery for cancer, despite an increase in surgical risk, the implementation of guidelines with predefined targets for hemodynamic and DOA monitoring was associated with a significant improvement in postoperative outcome.
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J Clin Monit Comput · Jun 2019
Comparative Study Observational StudyCardiac output and stroke volume variation measured by the pulse wave transit time method: a comparison with an arterial pressure-based cardiac output system.
Hemodynamic monitoring is mandatory for perioperative management of cardiac surgery. Recently, the estimated continuous cardiac output (esCCO) system, which can monitor cardiac output (CO) non-invasively based on pulse wave transit time, has been developed. Patients who underwent cardiovascular surgeries with hemodynamics monitoring using arterial pressure-based CO (APCO) were eligible for this study. ⋯ The time course had no effects on the biases between CO and SVV. Concordance rates were 80.3 and 75.7% respectively. While CO measurement with esCCO can be a reliable monitor after cardiovascular surgeries, SVV measurement with esCCO may require further improvement.
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J Clin Monit Comput · Jun 2019
Optimizing target control of the vessel rich group with volatile anesthetics.
The ability to monitor the inspired and expired concentrations of volatile anesthetic gases in real time makes these drugs implicitly targetable. However, the end-tidal concentration only represents the concentration within the brain and the vessel rich group (VRG) at steady state, and very poorly approximates the VRG concentration during common dynamic situations such as initial uptake and emergence. How should the vaporization of anesthetic gases be controlled in order to optimally target VRG concentration in clinical practice? Using a generally accepted pharmacokinetic model of uptake and redistribution, a transfer function from the vaporizer setting to the VRG is established and transformed to the time domain. ⋯ Using a simple and clinically intuitive modification to the targeting algorithm, a variable low-pass boundary layer is applied to the actuation, smoothing discontinuities in the control law and practically eliminating chatter without prolonging the time taken to reach the VRG target concentration by any clinically significant degree. A model is derived for optimum VRG-targeted control of anesthetic vaporizers. An alternate and further application is described, in which deliberate perturbation of the vaporization permits non-invasive estimation of parameters such as cardiac output that are otherwise difficult to measure intra-operatively.
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J Clin Monit Comput · Jun 2019
Objectively measured early physical activity after total hip or knee arthroplasty.
Although reduced early physical function after total hip- and knee arthroplasty (THA/TKA) is well-described, the underlying reasons have not been clarified with detailed studies on pathophysiological mechanisms related to recovery, thereby prohibiting advances in rehabilitation. Thus, we aimed to describe early post-THA/TKA physical activity measured by actigraphy and potential underlying pathophysiological mechanisms related to recovery in a well-defined cohort of THA and TKA patients. Daytime-activity was measured from 2 days before until 13 (THA) or 20 (TKA) days after surgery. ⋯ Physical activity was reduced the first weeks following THA/TKA, but with large inter-individual variations in recovery profiles. No single pathogenic factor was associated with a poor recovery. Early risk stratified interventions are needed in patients on a suboptimal course.