Journal of clinical monitoring and computing
-
J Clin Monit Comput · Feb 2021
Comparison of arterial CO2 estimation by end-tidal and transcutaneous CO2 measurements in intubated children and variability with subject related factors.
Transcutaneous PCO2 (PTCCO2) and end-tidal PCO2 (PETCO2) measurement methods serve as alternatives to arterial PCO2 (PaCO2), providing continuous non-invasive monitoring. The objective of this study was to evaluate the PTCCO2 and PETCO2 methods with actual PaCO2 levels, and to assess the variability of measurements in relation to subject-related factors, such as skin and subcutaneous adipose tissue thickness and presence of pulmonary diseases. PTCCO2, PETCO2 and PaCO2 were measured at the same time in intubated pediatric subjects. ⋯ Multiple linear regression demonstrated that increased subcutaneous adipose tissue thickness, core body temperature and inotropic index were related with higher PTCCO2 values relative to the actual PCO2 values. Other factors, such as skin tissue thickness, presence of pulmonary disease, measurement location and measurement times were non-significant. The PTCCO2 method has higher reliability than the PETCO2 method, and PTCCO2 measurements are not influenced by most subject-related factors; however, core body temperature, inotropic index and subcutaneous adipose tissue thickness can lead to significant differences in PCO2 measurement.
-
J Clin Monit Comput · Feb 2021
ReviewMetrology part 2: Procedures for the validation of major measurement quality criteria and measuring instrument properties.
A measurement is always afflicted with some degree of uncertainty. A correct understanding of the different types of uncertainty, their naming, and their definition is of crucial importance for an appropriate use of the measuring instruments. However, in perioperative and intensive care medicine, the metrological requirements for measuring instruments are poorly defined and often used spuriously. ⋯ It is therefore the task of scientific societies to establish the standards in their area of expertise. After adopting the same understandings and definitions (part 1), the different procedures for the validation of major quality criteria of measuring devices must be consensually established. In this metrologic review (part 2), we review the terms and definitions of validation, some basic processes leading to the display of an indication from a physiologic signal, and procedures for the validation of measuring instrument properties, with specific focus on perioperative and intensive care medicine including appropriate examples.
-
J Clin Monit Comput · Feb 2021
Randomized Controlled TrialReverse Trendelenburg position applied prior to pneumoperitoneum prevents excessive increase in optic nerve sheath diameter in laparoscopic cholecystectomy: randomized controlled trial.
The aim of this randomized controlled trial was to determine whether applying the reverse Trendelenburg position before pneumoperitoneum has a preventive effect on increased intracranial pressure using optic nerve sheath diameter (ONSD) measurement as a noninvasive parameter. Seventy-nine patients were allocated to two groups according to whether pneumoperitoneum was applied in the supine position (group S, n = 40) or in the reverse Trendelenburg position (group RT, n = 39). The ONSD was measured at the following time points: T0: before anesthesia; T1: after endotracheal intubation; T2: after pneumoperitoneum in group S and after positioning in group RT; T3: after positioning in group S and after pneumoperitoneum in group RT; T4: 30 min after endotracheal intubation, and T5: after desufflation. ⋯ The number of patients with nausea was higher in group S (p = 0.027). The present study demonstrates that applying the reverse Trendelenburg position before pneumoperitoneum prevented an increase in the ONSD in patients undergoing laparoscopic cholecystectomy. Trial registration The trial was registered prior to patient enrollment at https://register.clinicaltrials.gov (NCT04224532, Date of the registration: January 8, 2020).
-
J Clin Monit Comput · Feb 2021
Observational StudyEffects of varying remifentanil concentrations on Analgesia Nociception Index® under propofol: an observational study.
Analgesia Nociception Index monitor provides a measurement of the nociception and anti-nociception balance based on heart-rate variability. The aim was to assess the ability of Analgesia Nociception Index (ANI) to detect standard noxious stimulation during anesthesia at different opioid concentrations in comparison to hemodynamic and Bispectral Index parameters. Sixteen patients undergoing general anesthesia with propofol and remifentanil. ⋯ ANI was the only variable that positively correlated with the different remifentanil concentrations (R = 0.959, P = 0.01). Our study showed that there was a significant decrease in Analgesia Nociception Index after a tetanic stimulation while hemodynamic and BIS parameters did not change, suggesting that the Analgesia Nociception Index may perform better than traditional hemodynamic parameters at reflecting noxious stimulation. Analgesia Nociception Index significantly changed at lower, but not at higher, remifentanil concentrations.
-
J Clin Monit Comput · Feb 2021
Pulse oximetry based on photoplethysmography imaging with red and green light : Calibratability and challenges.
Remotely measuring the arterial blood oxygen saturation (SpO2) in visible light (Vis) involves different probing depths, which may compromise calibratibility. This paper assesses the feasibility of calibrating camera-based SpO2 (SpO2,cam) using red and green light. Camera-based photoplethysmographic (PPG) signals were measured at 46 healthy adults at center wavelengths of 580 nm (green), 675 nm (red), and 840 nm (near-infrared; NIR). ⋯ Additional measurements on normoxic subjects under temperature cooling (from [Formula: see text] to [Formula: see text]) evidenced a significant bias of - 1.7, CI [- 2.7, - 0.7]%. It was also noted that SpO[Formula: see text] estimated at the cheeks was significantly biased (- 3.6, CI [- 5.7, - 1.5]%) with respect to forehead estimations. Under controlled conditions, SpO[Formula: see text] can be calibrated with red and green light but the accuracy is less than that of SpO[Formula: see text] estimated in the usual red-NIR window.