Journal of clinical monitoring and computing
-
J Clin Monit Comput · Apr 2017
Observational StudyUtility of stroke volume variation measured using non-invasive bioreactance as a predictor of fluid responsiveness in the prone position.
The aim of this prospective study was to evaluate the usefulness of stroke volume variation (SVV) derived from NICOM® to predict fluid responsiveness in the prone position. Forty adult patients undergoing spinal surgery in the prone position were included in this study. We measured SVV from NICOM® (SVVNICOM) and FloTrac™/Vigileo™ systems (SVVVigileo), and pulse pressure variation (PPV) using automatic (PPVauto) and manual (PPVmanual) calculations at four time points including supine and prone positions, and before and after fluid loading of 6 ml kg-1 colloid solution. ⋯ The optimal cut-off values were 12 % for SVVNICOM, SVVVigileo, and PPVauto, and 10 % for PPVmanual. SVV from NICOM® successfully predicts fluid responsiveness during surgery in the prone position. This totally non-invasive technique for assessing individual functional intravenous volume status would be useful in a wide range of surgeries performed in the prone position.
-
J Clin Monit Comput · Apr 2017
Frequency characteristics of pressure transducer kits with inserted pressure-resistant extension tubes.
The accurate monitoring of arterial blood pressure is important for cardiovascular management. However, the frequency characteristics of pressure transducer kits are influenced by the length of the pressure-resistant tube. To date, there have been few studies addressing the frequency characteristics of pressure transducer kits with inserted pressure-resistant extension tubes (pressure-resistant extension tube (ET) circuits). ⋯ For the ET210 circuit, the natural frequency and damping coefficient were 25.3 Hz and 0.180, respectively. As a result of extending the circuit, it was found that the natural frequency decreased drastically, while the damping coefficient increased slightly. When the extension of a pressure transducer kit is required, we should pay careful attention to the major decrease in the natural frequency, which may influence the pressure monitoring.
-
J Clin Monit Comput · Apr 2017
Can intracranial pressure be measured non-invasively bedside using a two-depth Doppler-technique?
Measurement of intracranial pressure (ICP) is necessary in many neurological and neurosurgical diseases. To avoid lumbar puncture or intracranial ICP probes, non-invasive ICP techniques are becoming popular. A recently developed technology uses two-depth Doppler to compare arterial pulsations in the intra- and extra-cranial segments of the ophthalmic artery for non-invasive estimation of ICP. ⋯ The correlation between invasive and non-invasive ICP measurements was good (R = 0.74), and the 95 % limits of agreements were -1.4 ± 8.8 mmHg. The within-patient correlation varied between 0.47 and 1.00. This non-invasive technique is promising, and these results encourage further development and evaluation before the method can be recommended for use in clinical practice.
-
J Clin Monit Comput · Apr 2017
Practice patterns in the intraoperative use of bispectral index monitoring.
Assessing the depth of anesthesia and reducing intraoperative awareness has become a focus of much technology development and research in the field of anesthesia. Bispectral index (BIS) is the most widely utilized technology that uses electroencephalogram to provide a measurement of anesthetic depth. There are no definitive guidelines on when BIS should be used. ⋯ Factors associated with BIS use included increased age, greater ASA physical status, extremes of BMI, use of TIVA, use of a long-acting paralytic agent, use of an endotracheal tube (ETT), emergency surgery, increasing length of case, and certain surgical services. BIS use was associated with previously documented risk factors for intraoperative awareness. These factors are also indicators of case complexity, which may be a major factor among providers deciding when to apply BIS monitoring in the operating room.
-
J Clin Monit Comput · Apr 2017
Case ReportsFalsely low values of oxygen saturation measured by pulse oximetry in a boy treated with Chinese herb tea.
An 8-year-old boy suffering from progressive glioblastoma was scheduled for neurosurgery. Prior to induction of anaesthesia pulse oximetry measured 64 % saturation of oxygen (SpO2). Arterial blood gas analysis revealed normal oxygen saturation and normal oxygen partial pressure. ⋯ Blood samples were taken and analysed. Absorption spectroscopy from the patient's blood showed an uncommon absorption maximum at 684 nm besides the normal maxima. The normalisation of SpO2 values after stopping Chinese herb tea administration leads to the conclusion that one of its ingredients caused the distorted pulse oximetry measurement.