Journal of clinical monitoring and computing
-
J Clin Monit Comput · Apr 2014
Improved spatial resolution and electrogram wave direction independence with the use of an orthogonal electrode configuration.
To improve spatial resolution in recordings of intra-cardiac electrograms we characterized the utility of a novel configuration of two recording electrodes arranged perpendicularly to the endocardial surface. We hypothesized that this configuration denoted as orthogonal close unipolar (OCU) would combine advantages of conventional unipolar and contact bipolar (CBP) configurations. Electrical excitation was simulated in a computational model as arising from dipole current or from multi-wavelet reentry sources. ⋯ The difference between the actual dominant frequency in the tissue and that recorded by the electrodes was 0.44 ± 0.33 Hz for OCU, 0.58 ± 0.40 Hz for unipolar, and 0.62 ± 0.46 Hz for CBP. OCU confers improved spatial resolution compared with both unipolar and CBP electrode configurations. Unlike the case with CBP, OCU recordings are independent of excitation wave-front direction.
-
J Clin Monit Comput · Apr 2014
Comparative StudyPeripheral tissue oximetry: comparing three commercial near-infrared spectroscopy oximeters on the forearm.
Estimation of regional tissue oxygenation (rStO2) by near infrared spectroscopy enables non-invasive end-organ oxygen balance monitoring and could be a valuable tool in intensive care. However, the diverse absolute values and dynamics of different devices, and overall poor repeatability of measurements are a problem. The aim of the present study is to test the hypothesis that INVOS 5100C, FORE-SIGHT and NONIN EQUANOX 7600 have similar properties concerning absolute values, repeatability, and sensitivity to changes in rStO2. ⋯ Two measures of signal-to-noise were similar among devices. This suggests that good repeatability comes at the expense of low sensitivity to changes in oxygenation. Values of rStO2 on the forearm from INVOS, NONIN and FORE-SIGTH cannot be used interchangeably.
-
J Clin Monit Comput · Apr 2014
Comparative StudyElevated preoperative blood pressure predicts the intraoperative loss of SSEP neuromonitoring signals during spinal surgery.
Intraoperative neuromonitoring of somatosensory evoked potentials (SSEPs) can allow identification of evolving neurologic deficit. However, SSEP deterioration is not always associated with postoperative deficit. Transient physiologic changes, including a decrease in blood pressure (BP), can result in signal deterioration, defined as a decrease in waveform amplitude of[50 %seen without neurologic deficit. ⋯ While the presence of preoperative elevated BP predicts SSEP abnormality (p = 0.0039), a diagnosis of hypertension does not. Elevated BP, not a hypertension diagnosis, is associated with intraoperative loss of SSEP signals. This effect of elevated BP on SSEPs may be due to the larger associated intraoperative BP decline.
-
J Clin Monit Comput · Apr 2014
Controlled Clinical TrialEnd-tidal versus manually-controlled low-flow anaesthesia.
During low-flow manually-controlled anaesthesia (MCA) the anaesthetist needs constantly adjust end-tidal oxygen (EtO2) and anaesthetic concentrations (EtAA) to assure an adequate and safe anaesthesia. Recently introduced anaesthetic machines can automatically maintain those variables at target values, avoiding the burden on the anaesthetist. End-tidal-controlled anaesthesia (EtCA) and MCA provided by the same anaesthetic machine under the same fresh gas flow were compared. ⋯ In MCA patients the number of manual adjustments to stabilize EtAA and EtO2 were 137 and 107, respectively; no adjustment was required in EtCA. Low-flow anaesthesia delivered with an anaesthetic machine able to automatically control EtAA and EtO2 provided the same clinical stability and avoided the continuous manual adjustment of delivered sevoflurane and oxygen concentrations. Hence, the anaesthetist could dedicate more time to the patient and operating room activities.
-
J Clin Monit Comput · Apr 2014
FaceTime(®) for teaching ultrasound-guided anesthetic procedures in remote place.
In isolated area in Japan, only one anesthesiologist must often do new anesthetic techniques such as ultrasound-guided procedures without receiving any teaching. One solution to this problem may involve teleanesthesia, by which experienced anesthesiologists teach novices in remote places, by utilizing information communication technologies. FaceTime™ (Apple, USA), which provides 120p of the resolution and 30 frames per second (fps) is an application of free visual communications using iPod Touch™, iPhone™ or iPad™ (Apple, USA). ⋯ The delay time of iPhone5 was significantly longer than the others (iPod Touch; 0.14 ± 0.02 s, iPhone4; 0.13 ± 0.02 s, iPhone5; 0.19 ± 0.03 s), but clinically acceptable. The loss of the frames of iPhone5 (20; 1.1%) was significantly less than the others (iPhone4; 900, 50.0%, iPod Touch; 902, 50.1%). To teach anesthetic techniques in remote place by FaceTime, iPhone5 as the devise in isolate site was optimum compared with iPod Touch and iPhone4.