Journal of Clinical Monitoring and Computing最新文献

Blood pressure is a very important clinical measurement, offering valuable insights into the hemodynamic status of patients. Regular monitoring is crucial for early detection, prevention, and treatment of conditions like hypotension and hypertension, both of which increasing morbidity for a wide variety of reasons. This monitoring can be done either invasively or non-invasively and intermittently vs. continuously. An invasive method is considered the gold standard and provides continuous measurement, but it carries higher risks of complications such as infection, bleeding, and thrombosis. Non-invasive techniques, in contrast, reduce these risks and can provide intermittent or continuous blood pressure readings. This review explores modern machine learning-based non-invasive methods for blood pressure estimation, discussing their advantages, limitations, and clinical relevance.

Measuring spontaneous swallowing frequencies (SSF), coughing frequencies (CF), and the temporal relationships between swallowing and coughing in patients could provide valuable clinical insights into swallowing function, dysphagia, and the risk of pneumonia development. Medical technology with these capabilities has potential applications in hospital settings. In the management of intensive care unit (ICU) patients, monitoring SSF and CF could contribute to predictive models for successful weaning from ventilatory support, extubation, or tracheal decannulation. Furthermore, the early prediction of pneumonia in hospitalized patients or home care residents could offer additional diagnostic value over current practices. However, existing technologies for measuring SSF and CF, such as electromyography and acoustic sensors, are often complex and challenging to implement in real-world settings. Therefore, there is a need for a simple, flexible, and robust method for these measurements. The primary objective of this study was to develop a system that is both low in complexity and sufficiently flexible to allow for wide clinical applicability. To construct this model, we recruited forty healthy volunteers. Each participant was equipped with two medical-grade sensors (Movesense MD), one attached to the cricoid cartilage and the other positioned in the epigastric region. Both sensors recorded tri-axial accelerometry and gyroscopic movements. Participants were instructed to perform various conscious actions on cue, including swallowing, talking, throat clearing, and coughing. The recorded signals were then processed to create a model capable of accurately identifying conscious swallowing and coughing, while effectively discriminating against other confounding actions. Training of the algorithm resulted in a model with a sensitivity of 70% (14/20), a specificity of 71% (20/28), and a precision of 66.7% (14/21) for the detection of swallowing and, a sensitivity of 100% (20/20), a specificity of 83.3% (25/30), and a precision of 80% (20/25) for the detection of coughing. SSF, CF and the temporal relationship between swallowing and coughing are parameters that could have value as predictive tools for diagnosis and therapeutic guidance. Based on 2 tri-axial accelerometry and gyroscopic sensors, a model was developed with an acceptable sensitivity and precision for the detection of swallowing and coughing movements. Also due to simplicity and robustness of the set-up, the model is promising for further scientific research in a wide range of clinical indications.

Purpose: Regional anaesthesia techniques provide highly effective alternative to general anaesthesia. Existing evidence on the effect of spinal anaesthesia (SA) on cardiac diastolic function is scarce. This study aimed to evaluate the effects of a single-injection, low-dose SA on left ventricular end-diastolic pressures (LVEDP) using echocardiography in euvolaemic patients undergoing elective vascular surgery.

Methods: This is a prospective study in adult patients undergoing elective vascular surgery with SA. Patients with contraindications for SA or significant valvular disease were excluded. During patients' evaluations fluid administration was targeted using arterial waveform monitoring. All patients underwent echocardiographic studies before and after SA for the assessment of indices reflective of diastolic function. LVEDP was evaluated using the E/e' ratio. Blood samples were drawn to measure troponin and brain natriuretic peptide (BNP) levels before and after SA.

Results: A total of 62 patients (88.7% males, 71.00 ± 9.42 years) were included in the analysis. In total population, end-diastolic volume (EDV, 147.51 ± 41.36 vs 141.72 ± 40.13 ml; p = 0.044), end-systolic volume (ESV, 69.50 [51.50] vs 65.00 [29.50] ml; p < 0.001) and E/e' ratio significantly decreased (10.80 [4.21] vs. 9.55 [3.91]; p = 0.019). In patients with elevated compared to those with normal LVEDP, an overall improvement in diastolic function was noted. The A increased (- 6.58 ± 11.12 vs. 6.46 ± 16.10; p < 0.001) and E/A decreased (0.02 ± 0.21 vs. - 0.36 ± 0.90; p = 0.004) only in the elevated LVEDP group. Patients with elevated LVEDP had a greater decrease in E/e' compared to those with normal LVEDP (- 0.03 ± 2.39 vs. - 2.27 ± 2.92; p = 0.002).

Conclusion: This study in euvolaemic patients undergoing elective vascular surgery provides evidence that SA improved LVEDP.

Critically ill or anesthetized patients commonly receive pump-driven intravenous infusions of potent, fast-acting, short half-life medications for managing hemodynamics. Stepwise dosing, e.g. over 3-5 min, adjusts physiologic responses. Flow rates range from < 0.1 to > 30 ml/h, depending on pump type (large volume, syringe) and drug concentration. Most drugs are formulated in aqueous solutions. Hydrophobic drugs are formulated as lipid emulsions. Do the physical and chemical properties of emulsions impact delivery compared to aqueous solutions? Does stepwise dose titration by the pump correlate with predicted plasma concentrations? Precise, gravimetric, flow rate measurement compared delivery of a 20% lipid emulsion (LE) and 0.9% saline (NS) using different pump types and flow rates. We measured stepwise delivery and then computed predicted plasma concentrations following stepwise dose titration. We measured the pharmacokinetic coefficient of short-term variation, (PK-CV), to assess pump performance. LE and NS had similar mean flow rates in stepwise rate increments and decrements between 0.5 and 32 ml/h and continuous flows 0.5 and 5 ml/h. Pharmacokinetic computation predictions suggest delayed achievement of intended plasma levels following dose titrations. Syringe pumps exhibited smaller variations in PK-CV than large volume pumps. Pump-driven deliveries of lipid emulsion and aqueous solution behave similarly. At low flow rates we observed large flow rate variability differences between pump types showing they may not be interchangeable. PK-CV analysis provides a quantitative tool to assess infusion pump performance. Drug plasma concentrations may lag behind intent of pump dose titration.

Transthoracic echocardiography is widely used in intensive care unit (ICU) to manage patients with acute circulatory failure. Recently, automated ultrasound (US) measurement applications have been developed but their clinical performance has not been evaluated yet. The aim of this study was to assess the agreement between automated and manual measurements of the velocity–time integral in the left ventricular outflow tract (VTI-LVOT) using the auto-VTI® tool. This prospective, single-center, interventional study included ICU patients with acute circulatory failure. The examination involved two successive manual measurements of VTI-LVOT (mean of 3 consecutive heartbeats in regular sinus rhythm, and 5 heartbeats in irregular rhythm), followed by a measurement using auto-VTI® software. In patients receiving a fluid challenge, trending ability in detecting fluid responsiveness was also evaluated. Seventy patients were included between January 19, 2020, and September 24, 2020, at the Nîmes University Hospital. The feasibility of the auto-VTI® was 94%. The mean difference between the two methods was 11% with limits of agreement from − 19% to 42%. The proportion of agreement at the 15% difference threshold was 68% [58%; 80%]. The precision and least significant change measured for the manual measurement of VTI were 7.4 and 10.5%, respectively, and by inference for the automated method 28% and 40%. The new auto-VTI® tool, despite interesting feasibility, demonstrated an insufficient agreement with a systematic bias and an insufficient precision limiting its implementation in critically ill patients.

Clinical trial registration: ClinicalTrials.gov identifier: NCT04360304.

Abstract

To identify baseline biomarkers of delayed neurocognitive recovery (dNCR) using monitors commonly used in anesthesia. In this sub-study of observational prospective cohorts, we evaluated adult patients submitted to general anesthesia in a tertiary academic center in the United States. Electroencephalographic (EEG) features and cerebral oximetry were assessed in the perioperative period. The primary outcome was dNCR, defined as a decrease of 2 scores in the global Montreal Cognitive Assessment (MoCA) between the baseline and postoperative period. Forty-six adults (median [IQR] age, 65 [15]; 57% females; 65% American Society of Anesthesiologists (ASA) 3 were analyzed. Thirty-one patients developed dNCR (67%). Baseline higher EEG power in the lower alpha band (AUC = 0.73 (95% CI 0.48–0.93)) and lower alpha peak frequency (AUC = 0.83 (95% CI 0.48–1)), as well as lower cerebral oximetry (68 [5] vs 72 [3], p = 0.011) were associated with dNCR. Higher EEG power in the lower alpha band, lower alpha peak frequency, and lower cerebral oximetry values can be surrogates of baseline brain vulnerability.

Graphical abstract

Background: Processed electroencephalographic (EEG) indices can help to navigate general anesthesia. The CONOX (Fresenius Kabi) calculates two indices, the qCON (hypnotic level) and the qNOX (nociception). The CONOX also calculates indices for electromyographic (EMG) activity and EEG burst suppression (BSR). Because all EEG parameters seem to influence each other, our goal was a detailed description of parameter relationships. Methods: We used qCON, qNOX, EMG, and BSR information from 14 patients receiving propofol anesthesia. We described index relationships with linear models, heat maps, and box plot representations. We also evaluated associations between qCON/qNOX and propofol/remifentanil effect site concentrations (ceP/ceR). Results: qNOX and qCON (qCON = 0.79*qNOX + 5.8; p < 0.001; R² = 0.84) had a strong linear association. We further confirmed the strong relationship between qCON/qNOX and BSR for qCON/qNOX < 25: qCON=-0.19*BSR + 25.6 (p < 0.001; R² = 0.72); qNOX=-0.20*BSR + 26.2 (p < 0.001; R² = 0.72). The relationship between qCON and EMG was strong at higher indices: qCON = 0.55*EMG + 33.0 (p < 0.001; R² = 0.68). There was no qCON > 80 without EMG > 0. The relationship between ceP and qCON was qCON=-3.8*ceP + 70.6 (p < 0.001; R² = 0.11). The heat maps also suggest that the qCON and qNOX can at least partially separate the hypnotic and analgetic components of anesthesia. Conclusion: We could describe relationships between qCON, qNOX, EMG, BSR, ceP, and ceR, which may help the anaesthesiologist better interpret the information provided. One major finding is the dependence of qCON > 80 on EMG activity. This may limit the possibility of detecting wakefulness in the absence of EMG. Further, qNOX seems generally higher than qCON, but high opioid doses may lead to higher qCON than qNOX indices.

Somatosensory evoked potentials are frequently acquired by stimulation of the median or tibial nerves (mSEPs and tSEPs) for intraoperative monitoring of sensory pathways. Due to their low amplitudes it is common practice to average 200 or more sweeps to discern the evoked potentials from the background EEG. The aim of this study was to investigate if an algorithm designed to determine the lowest sweep count needed to obtain reproducible evoked potentials in each patient significantly reduces the median necessary sweep count to under 200. 30 patients undergoing spinal surgery at the Department of Neurosurgery were included in the study. Beginning with a sweep count of 200 an algorithm was designed to determine the lowest sweep count that yielded reproducible evoked potentials in each patient. By this algorithm the minimal sweep count was determined in 15 patients for mSEPs and in 15 patients for tSEPs. The required sweep count was below 200 in 14 of 15 patients for mSEPs (93.3%) with a mean sweep count of 56 ± 51. For tSEPs the sweep count was below 200 in 11 of 15 patients (73.3%) with a mean sweep count of 106 ± 70 (mean ± SD). The calculated mean time to average the potentials could thereby be reduced from 48.8s to 13.7s for mSEPs and from 48.8s to 25.9s for tSEPs. The proposed algorithm allowed sweep count and acquisition time reduction in roughly 90% of all patients for mSEPs and in 70% of all patients for tSEPs.

Same-day discharge (SDD) after Laparoscopic Roux-En-Y Gastric Bypass (LRYGB) faces resistance due to possible undetected postoperative complications. These present with changes in vital signs, which continuous remote monitoring devices can detect. This study compared continuous vital signs monitoring using the Isansys Patient Status Engine™ with standard nursing vital signs measurements to assess the device's reliability in postoperative surveillance of patients undergoing LRYGB. We conducted a pilot study including patients who underwent LRYGB. During their hospital stay, patients were continuously monitored using the Isansys Patient Status Engine™ with Lifetouch™, Lifetemp™, and Nonin Pulse Oximeter™ sensors. The heart rate (HR), body temperature, and oxygen saturation (SpO₂) collected by the device were compared with standard nursing assessments. Thirteen patients with a mean body mass index of 41.5 ± 4.4 kg/m² were included. No major complications occurred. The median HR assessed by standard and continuous monitoring did not significantly differ (75.5 [69-88] vs. 77 [66-91] bpm, p = 0.995), nor did the mean values of SpO₂ (94.7 ± 2.0 vs. 93.7 ± 1.8%, p = 0,057). A significant difference was observed in median body temperature between the nursing staff and the monitoring device (36.3 [36.1-36.7] vs. 36.1 [34.5-36.6] degrees Celsius, p = 0.012), with a tendency for lower temperature measurements by the device. In conclusion, this is the first study on continuous postoperative surveillance using the Isansys Patient Status Engine™ monitoring device for LRYGB patients. Our results introduce a novel tool for more efficient surgery. Prospective randomized experimental studies are warranted to evaluate this method's efficacy and safety.