Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2014
Clinical TrialPrediction of hypotension in the beach chair position during shoulder arthroscopy using pre-operative hemodynamic variables.
Since hypotension in beach chair position (BCP) can lead to catastrophic neurologic complications, the prediction of hypotension is a matter of concern in the BCP under general anesthesia. We investigated whether pre-induction values of mean arterial pressure (MAP), stroke volume variation (SVV), cardiac index (CI), and stroke volume index (SVI) can predict hypotension in BCP during general anesthesia. Forty healthy adult patients, aged 18-65 years, undergoing elective arthroscopic shoulder surgery, were enrolled. ⋯ The areas under the ROC curves for pre-induction values of MAP, CI, and SVI and post-induction value of SVV before a positional change were 0.556 (95% CI 0.373-0.739; p = 0.557), 0.735 (0.576-0.894; p = 0.014), 0.787 (0.647-0.926; p = 0.003), and 0.691 (0.525-0.857; p = 0.046), respectively. In this study, pre-induction values of CI and SVI and post-induction value of SVV before a positional change predicted hypotension in the BCP under general anesthesia. Our findings suggest that not only preload but also preoperative cardiac performances might be the important factors for the development of hypotension after a repositioning supine to the sitting during general anesthesia.
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J Clin Monit Comput · Apr 2014
Letter Case ReportsAn abrupt reduction in end-tidal carbon-dioxide during neurosurgery is not always due to venous air embolism: a capnograph artefact.
Venous air embolism (VAE) is a well recognized complication during neurosurgery. Pre-cordial doppler and trans-esophageal echocardiography are sensitive monitors for the detection of VAE. A sudden, abrupt reduction in the end-tidal carbondioxide (ETCO2) pressure with associated hypotension during neurosurgery might suggest VAE, when more sensitive monitors are not available. We describe an unusual cause for sudden reduction in ETCO2 during neurosurgery and discuss the mechanism for such presentation.
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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.
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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.
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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.