Journal of Clinical Monitoring and Computing最新文献

In response to the recent proposal by Monares-Zepeda et al. to estimate mean systemic filling pressure (MSFP) using cardiac power (CP) as a surrogate for the venous return pressure gradient (VRg), we raise concerns regarding the physiological validity and generalizability of the reported correlation. We demonstrate through simulation that the relationship between CP and VRg arises from structural mathematical coupling due to shared dependence on cardiac output (CO), and that this correlation weakens significantly (r = 0.54) when realistic physiological variability is introduced. We further argue that CP and VRg reflect distinct hemodynamic domains, and caution against interpreting their empirical correlation as evidence of physiological interchangeability. We call for broader validation of the model across diverse circulatory conditions. Comment on: 'Presentation of a novel method to estimate analog mean systemic filling pressure based on cardiac power' -on Correlation, Coupling, and Physiological Meaning.

Mean systemic filling pressure (MSFP) is a critical hemodynamic parameter for managing critically ill patients. Existing estimation methods either require invasive procedures or assume constant vascular resistances, limiting their applicability in clinical settings. We propose a novel method to estimate MSFP using cardiac power (CP), this method was developed in a cohort of 50 patients, validated in a different cohort of 50 patients, and tested in a historical cohort of 21 patients, showing a high correlation (r = 0.95 - 0.90) and agreement with Parkin analog Mean Systemic Filling Pressure (MSFPa) method. In brief MSFPe = (3.3*CP) + 2.2 + CVP. Our method provides an accurate, non-invasive bedside approach for estimating MSFP, facilitating hemodynamic assessment in critically ill patients and opening new research avenues on vascular resistance dynamics.

We thank the authors for their interest in our work and their valuable comments. Our response addresses three main points. First, we clarify that the method we presented, deriving mean systemic filling pressure (MSFP) from cardiac power, is a simplification of the Parkin formula. This formula has been validated in both experimental and clinical studies, and we have confirmed its correlation with our approach across different populations. Second, we emphasize the advantage of our method over the Parkin approach: it does not require patient-specific variables such as age, weight, or height, nor does it rely on the assumption of a constant venous-to-arterial compliance ratio (Cv/Ca) of 25:1, which may not always apply. Finally, we identify a critical inconsistency in the authors' simulation model, which yields physiologically impossible values, with venous return resistance exceeding total systemic resistance. This issue highlights the need for further reevaluation.

Healthcare settings heavily rely on clinicians' abilities to interpret vital sign alarms indicating patient decompensation. Meanwhile, clinicians are bombarded with many multisensory stimuli necessary for patient care, including simultaneous visual and auditory displays. Here, we aim to assess how our modified auditory and visual alarm designs impact clinicians' perceived cognitive workload. This experimental study, conducted at Vanderbilt University Medical Center (VUMC) between March and September 2023, included 26 clinicians (nurse practitioners, residents, and fellows). Auditory trials involved 15 clinicians and non-clinicians (university students) to validate design intuitiveness. Clinicians participated in visual and auditory trials to identify simulated mean arterial pressure (MAP), utilizing standard and modified alarms. Visual modifications incorporated a line-graph display with a moving dot for MAP. Auditory modifications introduced harmonic overlays indicating severity and direction of MAP values. After each trial, participants completed the National Aeronautics and Space Administration Task Load Index (NASA-TLX) to assess perceived workload across 6 domains (temporal demand, physical demand, mental demand, effort, performance, frustration) on a 1-20 Likert scale with increased scores represent greater workload. For analysis, Wilcoxon signed-rank and rank-sum tests were used. Demographics for auditory alarm trials averaged an age of 26.2 and 54% identified as male. Visual display trials included 26 clinicians with an average age of 30.1 and 59% identified as male. In visual trials, clinicians reported significantly lower temporal demand with the modified monitor (median, interquartile range (IQR)) (8.0, 4.2-11.8) compared to the conventional monitor (13.0, 6.5-16.0; p = 0.022). In auditory trials, clinicians reported significantly higher perceived performance with conventional auditory alarms as compared to non-clinicians (10.0, 5.0-13.0) vs. (4.0, 2.0-9.0; p = 0.022). Non-clinicians reported higher perceived temporal demand for conventional auditory alarms when compared to clinicians (6.0, 3.0-10.0) vs. (2.5, 1.0-5.0; p = 0.024). Our findings suggest modifications to both visual and auditory alarms can reduce elements of perceived cognitive workload, especially temporal demand, while preserving clinician performance without deterioration of other measured components.

A recent study introduced a patient-specific algorithm designed to reduce the acquisition time required for obtaining somatosensory evoked potentials during spinal surgery. While the approach is promising, its reliance on amplitude and latency thresholds may overlook subtle waveform features that are crucial in high-risk patients. Broader validation, integration of waveform morphology, and cautious application in clinically compromised populations are warranted. Optimizing intraoperative neurophysiological monitoring requires not only speed but also diagnostic fidelity.