Journal of clinical monitoring and computing
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J Clin Monit Comput · Aug 2020
Detecting intraoperative gastric regurgitation by using preattached esophageal multichannel intraluminal impedance and pH monitoring on a solid-state manometry: a case series study.
Adequate barrier pressure (BrP), calculated by subtracting intragastric pressure (IGP) from lower esophageal sphincter pressure (LESP), is believed to prevent gastroesophageal regurgitation (GER). However, the occurrence of intraoperative GER, the height and acidity it reached, have rarely been demonstrated simultaneously along with BrP. In this study, we developed preattached multichannel intraluminal impedance monitoring combined with pH-metry (the gold standard for detecting both height and acidity) on a solid-state manometry to continuously detect intraoperative GER as well as BrP changes. ⋯ The mean IGP (3.24 mmHg) at T2 was significantly higher than at T1 and T3 (- 6.10 and - 2.25 mmHg, respectively). The mean BrP scores were comparable from T1 to T3 (T1: 19.34 mmHg; T2: 19.98 mmHg; T3: 21.16 mmHg). Based on our results, the proposed setup is helpful for intraoperative monitoring and management of patients at high risk of GER.
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J Clin Monit Comput · Aug 2020
Behavior of a dual closed-loop controller of propofol and remifentanil guided by the bispectral index for postoperative sedation of adult cardiac surgery patients: a preliminary open study.
A dual-loop controller permits the automated titration of propofol and remifentanil during anesthesia; it has never been used in intensive care after cardiac surgery. The goal of this preliminary study was to determine the efficacy of this controller to provide postoperative sedation in 19 adult cardiac surgery patients with a Bispectral Index target of 50. Results are presented as numbers (percentages) or medians [25th-75th percentiles]. ⋯ Automated sedation device was discontinued in two patients for hemodynamic instability. No patient had awareness of the postoperative sedation period. Dual closed-loop can provide postoperative sedation after cardiac surgery but the choice of the depth of sedation should take into account the risk of hypotension.
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J Clin Monit Comput · Aug 2020
Feasibility evaluation of non-invasive cardiac function technology during echocardiography-based cardiac stress testing.
Evaluation of cardiac function during periods of stress is of key importance for the perioperative setting. Non-invasive hemodynamic monitors provide markers of cardiac function. This pilot study sought to evaluate the ability of a non-invasive hemodynamic monitor to detect cardiac stress during formal stress echocardiography testing. ⋯ Comparison of the hemodynamic variables between patients who had a positive stress study versus negative showed a significant reduction in the percentage change in dP/dt and stroke volume from baseline (p < 0.05). This pilot study indicates that patients who have abnormal stress echocardiograms also have significantly reduced values from a noninvasive hemodynamic monitor. Further evaluation of the clinical utility of this technology, to assist in the care of patients at risk for cardiac ischemia, should be carried out.
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J Clin Monit Comput · Aug 2020
Ultrasonographic measurement of the ligamentum flavum at different angles in the lateral tilt position.
The aim of this study was to take ultrasonographic measurements of the length of the ligamentum flavum (LF), the LF-skin distance and the interspinous distance, which are critical for the application of neuraxial anaesthesia, with volunteers in the sitting position and with lateral tilt of the operating table at different angles to evaluate whether the target structures in neuraxial anaesthesia can be better visualised with the lateral tilt position and to determine whether or not these measurements change at different angles. The study included 29 volunteers. For the measurements, the operation table was first set into the neutral position and the length of the LF, the skin-LF distance and the interlaminar distance were measured at between L1-S1 spaces with a paramedian oblique sagittal approach with a linear ultrasound probe. ⋯ In the ultrasonographic measurements of the skin-LF distance, at L3-4 and L4-5 intervertebral interspaces, there was a statistically significant increase. With lateral tilt applied to the table, there was determined to be an increase in ultrasonographic measurements of the LF length in the lumbar intervertebral interspaces. Therefore, for neuraxial blocks applied in the sitting position, the procedure may be facilitated with lateral tilt of the operating table.
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J Clin Monit Comput · Jun 2020
Event-triggered averaging of electrical impedance tomography (EIT) respiratory waveforms as compared to low-pass filtering for removal of cardiac related impedance changes.
Electrical impedance tomography (EIT) is used for bedside ventilation monitoring; cardiac related impedance changes represent a source of noise superimposed on the ventilation signal, commonly removed by low-pass filtering (LPF). We investigated if an alternative approach, based on an event-triggered averaging (ETA) process, is more effective at preserving the actual ventilation waveform. Ten paralyzed patients undergoing volume-controlled ventilation were studied; 30 breaths for each patient were identified to compare LPF and ETA. ⋯ Both for global and regional waveforms, minimum and maximum EIT slopes were steeper by ETA as compared to LPF (average difference respectively - 57 ± 60 mL/s and 144 ± 96 mL/s for global signal, p < 0.05); ventilator inspiratory peak airflow correlated with maximum slope measured by ETA (r = 0.902, p < 0.001), but not LPF (p = 0.319). Beginning of inspiration identified on the ventilator waveform and on the global EIT signal by ETA occurred simultaneously, (+ 0.04 ± 0.07 s, p = 0.081), while occurred earlier by LPF (- 0.26 ± 0.1 s, p < 0.001). Removal of cardiac related impedance changes by ETA results in a ventilation signal more similar to the waveforms recorded by the ventilator, particularly regarding the slope of impedance changes and time at the minimum values as compared to LPF.