Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2021
Non-invasive measurement of pulse pressure variation using a finger-cuff method in obese patients having laparoscopic bariatric surgery.
Pulse pressure variation (PPV) is a dynamic cardiac preload variable used to predict fluid responsiveness. PPV can be measured non-invasively using innovative finger-cuff systems allowing for continuous arterial pressure waveform recording, e.g., the Nexfin system [BMEYE B. V., Amsterdam, The Netherlands; now Clearsight (Edwards Lifesciences, Irvine, CA, USA)] (PPVFinger). ⋯ The overall mean of the differences between PPVFinger and PPVART was 0.5 ± 4.6% (95%-LoA - 8.6 to 9.6%) and the overall predictive agreement was 72.4% with a Cohen's kappa of 0.53. The mean of the differences was - 0.7 ± 3.8% (95%-LoA - 8.1 to 6.7%) without pneumoperitoneum in horizontal position and 1.1 ± 4.8% (95%-LoA - 8.4 to 10.5%) during pneumoperitoneum in reverse-Trendelenburg position. The absolute agreement and predictive agreement between PPVFinger and PPVART are moderate in obese patients having laparoscopic bariatric surgery.
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J Clin Monit Comput · Dec 2021
Laser speckle contrast imaging of forehead cutaneous blood flow during carotid endarterectomy as a potential non-invasive method for surrogate monitoring of cerebral perfusion.
Monitoring cerebral perfusion is important for goal-directed anesthesia. Taking advantage of the supply of the supraorbital region and Glabella from the internal carotid artery (ICA), we evaluated changes in cutaneous blood flow using laser speckle contrast imagining (LSCI) as a potential method for indirect real-time monitoring of cerebral perfusion. Nine patients (8 men, mean age 70 years) underwent eversion carotid endarterectomy under local anesthesia. ⋯ The supraorbital cutaneous blood flow did not change significantly following reperfusion of the external carotid artery (ECA) (221 ± 109 to 281 ± 154 AU; p = 0.175) and ICA (281 ± 154 to 310 ± 184 AU; p = 01). A comparable trend for Glabella followed ECA (276 ± 107 to 342 ± 170 AU; p = 0.404) and ICA (342 ± 170 to 352 ± 191 AU; p = 01) reperfusion. In patients undergoing carotid endarterectomy under local anesthesia, LSCI of the supraorbital and Glabella regions reflected clamping of the CCA but did not distinguish reperfusion of the ICA from that of the ECA.
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J Clin Monit Comput · Dec 2021
Non-invasive indirect monitoring of intra-abdominal pressure using microwave reflectometry: system design and proof-of-concept clinical trial.
Monitoring intra-abdominal pressure (IAP) has become a standard in intensive care units. Correlation between the abdominal wall's thickness (AWTh) and IAP has been reported previously. The abdominal wall can be modeled as a compound of parallel dielectric slabs; changes in their width have a direct effect on the reflection coefficient of the abdominal wall at microwave frequencies. ⋯ C95.1-2005 concerning exposure of humans to microwave electromagnetic fields in controlled environments. The results putatively show an inverse correlation between IAP and the reflection coefficient, and a strong dependence on the body mass index. A better understanding of the dynamics in the changes of the AWTh (during intra-abdominal hypertension) will allow further development of a microwave-based technique for the continuous non-invasive indirect monitoring of IAP in critical patients.
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J Clin Monit Comput · Dec 2021
Using near-infrared spectroscopy myocardial oximetry to monitor myocardial oxygen balance in a swine model of cardiac surgery: a descriptive study.
Monitoring of the adequacy of myocardial protection with cardioplegia is nearly non-existent in clinical cardiac surgical practice and instead relies on well-defined protocols for delivery of cardioplegia often resulting in inadequate protection. We hypothesized that Near Infrared Spectroscopy technology could be useful in the monitoring of the myocardial oxygen state by attaching the monitors to the epicardium in a porcine model of cardiac surgery. The experiments were conducted with 3 different protocols of 2 pigs each for a total of 6 pigs. ⋯ We found that decreases in myocardial oxygen supply or increases in demand due to any of the various experimental conditions led to decreases in both myocardial tissue oximetry and hemoglobin oxygen saturation of coronary sinus blood with recovery when the conditions were returned to baseline. Correlation between myocardial tissue oximetry and hemoglobin oxygen saturation of coronary sinus blood was moderate to strong under all tested conditions. This may have translational applications as a monitor of adequacy of myocardial protection and the detection of coronary occlusion.
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J Clin Monit Comput · Dec 2021
ANI and BIS variations in supine and prone position during closed-tracheal suction in sedated and myorelaxed ICU patients with severe COVID-19: A retrospective study.
The purpose of this study was to assess Analgesia/Nociception Index (ANI) and bispectral index (BIS) variations in supine and prone position during closed-tracheal suction in intensive care unit (ICU) patients with severe COVID-19 pneumonia requiring myorelaxation and prone positioning. We retrospectively reviewed the data of 15 patients hospitalized in ICU for severe COVID-19 pneumonia requiring sedation, myorelaxation and prone positioning. The BIS, instant ANI (ANIi), mean ANI (ANIm), heart rate (HR), systolic blood pressure (SBP) and SpO2 were retrieved in supine and prone position 1 min before tracheal suction then every minute from the beginning of tracheal suction during 4 min and compared using ANOVA for repeated measures (p < 0.05 considered as statistically significant). ⋯ The median [Q1-Q3] ANIi value decreased earlier 1 min after the beginning of tracheal suction from 84 [69-98] to 73 [60-90] in supine position and from 84 [60-99] to 71 [51-88] in prone position. Both HR, SBP and SpO2 varied modestly but significantly during tracheal suction with no difference between positions. Monitoring ANI, but not BIS, may be of interest to detect noxious stimuli such as tracheal suction in ICU myorelaxed patients with severe COVID-19 pneumonia requiring prone positioning.