Journal of Clinical Monitoring and Computing最新文献

Respiratory rate is an important early sign of clinical deterioration but the current practice of counting breaths manually is time-consuming and prone to error. We aimed to determine the concordance between manual respiratory rate measurements and automated measurements recorded using a wearable device. We undertook a prospective observational study on three general respiratory wards to compare manual respiratory rate measurements collected during usual clinical care with automated readings from a wearable respiratory rate monitor (RespiraSense, PMD Solutions, Cork, Ireland). Thirty-one patients took part in the study. Manual respiratory rate readings displayed large peaks at 20 and 24 breaths/min, whereas automated readings followed a smooth bell-shaped distribution. Manual and automated respiratory rates were both higher during the day than at night, and this was more marked for automated readings. Automated readings were on average 2.5 (95% confidence interval [CI] 2.2 to 2.8) breaths/minute higher than time-matched manual readings, and the 95% limits of agreement were - 7.9 (95% CI -8.4 to -7.4) and 12.9 (95% CI 12.3 to 13.4) breaths/minute, wider than the clinically acceptable limits of ± 3 breaths/min. Trends in manual and automated respiratory rates were concordant in only 56% of cases. Automated respiratory rate measurements using RespiraSense do not display clinically acceptable agreement with manual measurements in the setting of a respiratory ward.

Functional testers are designed to evaluate select pulse oximeter characteristics but are often misused to validate device accuracy, potentially providing false reassurance. This study evaluated whether the Fluke ProSim8 (FPS8) could accurately predict oximeter performance during human controlled desaturation studies or identify performance differences under low signal conditions. 12 oximeters were tested using two FPS8 protocols: (1) an 'SpO₂ plateau' protocol which mimicked controlled desaturation studies by evaluating device performance over a range of simulated SpO₂ (70-100%), and (2) a 'signal space' protocol designed to assess device accuracy under varying modulation and transmission conditions. Each device also underwent controlled desaturation testing in healthy adults. Six of the 12 oximeters passed (ARMS ≤ 3%) the SpO₂ plateau protocol; however, three of these failed (ARMS > 3%) human testing. At lower simulated saturations, most devices overestimated SpO₂. In the signal space protocol, oximeters performed well under high signal conditions, but many failed to produce readings or showed SpO₂ errors > 3% under low signal conditions. On average, oximeters failed to generate a reading 20.2 ± 7.2 times out of 60 attempts. Ten devices passed (ARMS < 3%) the signal space protocol, but two of these failed human testing. Oximeter performance on the FPS8 did not correlate with human performance (R² = 0.08 for the plateau protocol; R² = 0.01 for the signal space protocol). The FPS8 did not reliably predict oximeter accuracy in human desaturation studies or under low signal conditions; current functional tester protocols are limited in predicting real-world oximeter performance.

Background: Accurately identifying surgical patients who will have an increase in stroke volume following fluid administration remains challenging when utilizing noninvasive bedside methods. This study aims to compare the value of using ultrasound to measure changes in corrected carotid artery flow time (ΔFTc) with that of using invasive measurements of stroke volume variation (ΔSVV) for assessing volume responsiveness in patients under general anesthesia and mechanical ventilation.

Methods: A total of 91 patients undergoing elective abdominal surgery under general anesthesia were enrolled in this prospective observational study. Under general anesthesia and mechanical ventilation, the ΔFTc was measured using noninvasive bedside ultrasound, and the ΔSVV was measured using invasive hemodynamic monitoring, both before and after fluid administration. Fluid responders were defined as an increase in stroke volume of ≥ 10% after the fluid challenge.

Results: A total of 47 (54.0%) patients were fluid responders. The ΔFTc was 14.5 ± 8.3 ms for responders and 5.7 ± 4.9 ms for non-responders, while the ΔSVV was 3.3 ± 1.4% for responders and 1.7 ± 0.7% for non-responders. The areas under the receiver operating characteristic curves for ΔFTc and ΔSVV were 0.85 (95% CI 0.77-0.92; P < 0.05) and 0.84 (95% CI 0.75-0.93; P < 0.05), respectively. The optimal cutoff values were 7.03 ms for ΔFTc (sensitivity 91.5%, specificity 69.8%) and 2.85% for ΔSVV (sensitivity 95.6%, specificity 72.6%). A narrower gray zone for ΔFTc, ranging from 7 ms to 12 ms and covering 27 patients, was observed compared with that for ΔSVV, which ranged from 1% to 3% and covered 41 patients.

Conclusions: Both the ΔFTc and ΔSVV reliably assessed fluid responsiveness in patients undergoing general anesthesia and mechanical ventilation. Noninvasive bedside ultrasound measurement of ΔFTc can serve as an accurate assessment parameter, reflecting the presence of volume responsiveness following rapid fluid administration and showing greater clinical applicability.

Trial registration: www.chictr.org.cn (ChiCTR2500101114); registered 21 April 2025.

Reduce sevoflurane consumption during anaesthesia remains an economic and environmental challenge. This case study analyzed retrospectively a large cohort of procedures using end-tidal (ET) Control to optimize sevoflurane consumption and assess the impact of ventilator settings on it. In single center, consecutive adult procedures for noncardiac surgery under general anaesthesia were analyzed in twelve operating rooms. The anaesthesia system (Aisys CS², GE, USA) was connected to software (Carestation Insight, GE, USA) that automatically recorded sevoflurane consumption for each case. Left to the discretion of the anaesthesiologist, fresh gas flow (FGF) was set at 0.5, 0.8 or 1 L.min^-1 with an initial end-tidal sevoflurane target of 1.2-2% to reach the goal of approximately 1.0 MAC. The primary endpoint was the sevoflurane consumption (mL.min^-1). Secondary endpoints were sevoflurane consumption and carbon footprint for the cohort (sevoflurane GWP₂₀ = 702) and by anaesthesia duration, type of airway management (endotracheal intubation EI, laryngeal mask LM), FGF and initial sevoflurane settings. From May to September 2024, 3064 procedures were recorded via the app. with a median (IQR) duration of surgery of 79 (47-124) minutes. Sevoflurane consumption was. 19 528 mL. Median (IQR) sevoflurane consumption was 0.16 (0.12-0.20) mL.min^-1 with a carbon footprint (sevoflurane GWP₂₀ including manufacturing = 1,468 kg/mL) of 0,23(0.17-0.29) kgCO_2eq.min^-1.Subgroup analysis demonstrated that FGF at 0.8 or 1.0 L.min^-1 significantly increased sevoflurane consumption and CO₂ emission when compared with 0.5 L.min^-1 (P < 0.01). Initial ET target sevoflurane levels of 1.2% vs greater than 1.2% did not change total sevoflurane consumption. Regarding airway management (EI vs LM), LM use was associated with higher consumption, specifically when duration > 120 min (P < 0.01). In this large cohort of cases, this study demonstrated that controlling ET with an FGF target of 0.5 L.min^-1 remained the best way to reduce sevoflurane consumption. Other settings did not significantly reduce gas consumption.

Burn shock is a major early complication in the treatment of severely burned patients, and precise and timely fluid management is essential for survival. Traditional clinical indicators such as urine output, blood pressure, central venous pressure (CVP), and blood lactate are commonly used, but each has significant limitations. Invasive hemodynamic monitoring technologies, such as Pulmonary Artery Catheterization (PAC) and Pulse Contour Cardiac Output (PiCCO), have improved the accuracy of fluid assessment, but carry risks of infection and procedural complications and require experienced clinical interpretation within the context of the patient's overall condition. Non-invasive ultrasound-based methods, including critical care ultrasonography and the Venous Excess Ultrasound Score (VExUS), are emerging as promising alternatives, particularly in resource-limited settings. This review summarizes current methods for fluid management in severely burned patients, with a focus on the concepts of fluid responsiveness and fluid tolerance, and provides recommendations for clinical practice.

Purpose: Electrical impedance tomography (EIT) is a functional imaging technique to monitor regional ventilation. However, the quantification of clinically used ventilation parameters like tidal volume (VT) has not been possible yet since EIT measures relative and not absolute changes in impedance. Thus, the study aimed to evaluate the relationship between impedance changes (dZ) and VT in humans and to identify influencing factors.

Methods: 27 patients undergoing elective surgery under general anaesthesia were equipped with a commercially available EIT belt. Measurements were performed at four VTs (6, 8, 10 and 12 mL/BW) on each of four PEEP levels (0, 5, 10 and 15 cmH₂O). Linear regression analysis was performed for normalized dZ and VT per ideal bodyweight (VT_IBW). Additionally, PEEP, gender, age, height and weight were analysed as potential influencing factors.

Results: Regression analysis for individual patients showed good correlations between VT_IBW and normalized dZ (mean R² 0.890 ± 0.15). However, for the group of patients, correlations were rather weak (R² 0.485). Including additional factors improved the model (adjusted R² 0.767), with VT_IBW having the biggest impact, followed by weight, height and PEEP; age did not contribute to it significantly. Higher VT_IBW, PEEP and height increased, while female gender and higher weight decreased normalized dZ.

Conclusion: Normalized dZ correlated strongly with VT_IBW in the individual ventilated humans but more weakly when analyzing the cohort. PEEP, gender, weight and height were identified as additional influencing factors.

Trial registration: This study was prospectively registered at the German Register of Clinical Studies (Deutsches Register Klinischer Studien; DRKS00027226) on 3rd December 2021.

Background: Despite the substantial advancements in mechanical ventilation (MV), mortality remains high. Mechanical power (MP), MV forces are associated with outcomes. Real-time monitoring of MP and the adjustment of MV according to MP may result in ventilation with lower MP.

Methods: Randomized controled trial conducted at the ECMO Centre Ostrava, Czech Republic, from March 2023 to March 2024 enrolled adult patients on MV (with or without extracorporeal membrane oxygenation, ECMO) with acute respiratory failure. A system for real-time MP monitoring (geometric method and simplified Becher´s formula) has been developed. In the intervention arm, the physician was able to observe the MP in real time and adjust the MV parameters accordingly. In the control group, the MP was concealed.

Results: A total of 494 subjects were screened and 33 patients were randomized (further 7 ECMO patients). There was no significant difference between the control and intervention groups. Median MP_Geom was 3.22 J/min (maximum 15.2 J/min) and MP_Becher of 5.94 J/min (maximum 18.4 J/min). Only a weak (but significant, p = 0.0001) correlation between MP_Geom and MP_Becher was observed. A highly significant difference was observed in MP between day and night (6 a.m. - 6 p.m.) with higher MP at night.

Conclusion: Although real-time MP measurement is feasible, there was no significant difference in MP between the control and intervention groups with low MP in both groups. Experience physicians was capable of safe MV, even if they do not know the exact MP value. The night shift was a high-risk period for developing lung damage due to elevated MP.

Trial registration: ClinicalTrials NCT06035146.

Purpose: This randomised controlled trial investigated the effect of Surgical Pleth Index (SPI) guided sufentanil administration on intraoperative sufentanil consumption compared to routine care in patients with a combination of general anaesthesia and regional anaesthesia having trauma and orthopaedic surgery.

Methods: Eighty patients with a combination of general anaesthesia and regional anaesthesia undergoing trauma or orthopaedic surgery were randomised into two groups to receive either sufentanil guided by SPI monitoring or by routine care (Control). The primary endpoint was intraoperative sufentanil consumption. Secondary endpoints were postoperative pain level, opioid consumption, incidence of nausea, duration of time in the post-anaesthesia care unit (PACU) and quality of recovery.

Results: The median intraoperative sufentanil administration adjusted to bodyweight and surgery duration did not differ between the groups: SPI guided group 2.29 (interquartile range, IQR 0.29 to 6.91), Control 1.65 (IQR 0.83 to 2.63) µg·kg^-1·min^-1*1000 (P = 0.906). The relative risk for receiving intraoperative sufentanil was RR 0.909 (95% CI 0.723 to  1.143, P = 0.414). Median morphine equivalents administered in the 24 h after discharge from the PACU were 3.8 (IQR 0.0 to 22.5) in the SPI guided group and 19.1 (IQR 3.8 to 30.0) mg (P = 0.021) in the control group without adjustment for multiple testing. Other secondary endpoints showed no differences.

Conclusion: SPI guided sufentanil administration did not reduce intraoperative sufentanil consumption compared to routine care in patients having trauma and orthopaedic surgery with a combination of general anaesthesia and regional anaesthesia.

Trial registration: Clinicaltrials.gov identifier NCT06040307 (registered September 8, 2023).

Purpose: This study provides an economic evaluation of bedside, data-driven, and model-informed precision dosing of antibiotics in comparison with usual care among critically ill patients with sepsis or septic shock.

Methods: This economic evaluation was conducted alongside an AutoKinetics randomized controlled trial. Effect measures included quality-adjusted life years (QALYs), mortality and pharmacokinetic target attainment. Costs were measured from a societal perspective. Missing data was multiply imputed, and bootstrapping was used to estimate statistical uncertainty. Differences in effects and costs were estimated using bivariate regression and used to calculate incremental cost-effectiveness ratios.

Results: Patients in the intervention group had higher costs (€42,684 vs. 39,475), lower mortality (42% vs. 49%), more QALYs (0.184 vs. 0.153), and higher pharmacokinetic target attainment (69% vs. 48%). Only the difference for target attainment was found statistically significant. An additional €18,129, €55,576, and €123,493 needs to be invested to attain the targeted plasma levels for one more patient, to save one life and gain one QALY, respectively. The probability of cost-effectiveness for all effect outcomes is below 60% for most acceptable willingness-to-pay thresholds.

Conclusions: Data-driven personalised antibiotic dosing in critically ill patients as implemented in the AutoKinetics trial cannot be recommended for implementation as a cost-effective intervention.

Trial registration: The trial was prospectively registered at Netherlands Trial Register (NTR), NL6501/NTR6689 on 25 August 2017 and at the European Clinical Trials Database (EudraCT), 2017-002478-37 on 6 November 2017.