Journal of clinical monitoring and computing
-
J Clin Monit Comput · Dec 2013
Quantification of the proportion of motor neurons recruited by transcranial electrical stimulation during intraoperative motor evoked potential monitoring.
Transcranial motor evoked potentials (TcMEPs) are widely used to monitor motor function during spinal surgery. However, they are much smaller and more variable in amplitude than responses evoked by maximal peripheral nerve stimulation, suggesting that a limited number of spinal motor neurons to the target muscle are excited by transcranial stimulation. The aim of this study was to quantify the proportion of motor neurons recruited during TcMEP monitoring under general anesthesia. ⋯ The average ratios (test:control) were 17.1 % (range 1.8-38 %) for the amplitudes and 21.6 % (range 2.9-40 %) for the areas. The activity of approximately 80 % of the motor units to the target muscle cannot be detected by TcMEP monitoring. Therefore, changes in evoked potentials must be interpreted cautiously when assessing segmental motor function with TcMEP monitoring.
-
J Clin Monit Comput · Dec 2013
Comparative Study Clinical TrialCardiac index assessment using bioreactance in patients undergoing cytoreductive surgery in ovarian carcinoma.
This clinical study compared the cardiac index (CI) assessed by the totally non-invasive method of bioreactance (CIBR) (NICOM™, Cheetah Medical, Vancouver, USA) to transpulmonary thermodilution (CITD) during cytoreductive surgery in ovarian carcinoma. The hypothesis was that CI could be assessed by bioreactance in an accurate and precise manner including accurate trending ability when compared to transpulmonary thermodilution. In 15 patients CIBR and CITD were assessed after induction of anesthesia, after opening of the peritoneum, hourly during the operative procedure, and 30 min after extubation. ⋯ CI assessment by bioreactance showed acceptable accuracy and trending ability. However, its precision was poor. Therefore, CI measurement can not be solely based on bioreactance in patients undergoing cytoreductive surgery in ovarian carcinoma.
-
J Clin Monit Comput · Dec 2013
Comparative Study Observational StudyThe impact of systemic vascular resistance on the accuracy of the FloTrac/Vigileo™ system in the perioperative period of cardiac surgery: a prospective observational comparison study.
FloTrac/Vigileo™ system is based on arterial pressure waveform analysis arterial pressure-based CO (APCO). Therefore, systemic vascular resistance (SVR) can influence the accuracy of APCO. The purpose of this study is to evaluate the relationship between SVR and the accuracy of APCO. ⋯ Subanalysis based on SVR with Lin's concordance correlation coefficient revealed that relatively satisfactory concordance was found in the normal-SVR group (concordance correlation coefficient ρ c = 0.51-0.56) regardless of vasoactive agent use. The accuracy of the FloTrac/Vigileo™ System (v. 3.02) is relatively satisfactory in the condition with normal SVR regardless of vasoactive agent use. Positive correlation between the bias and SVR can be the clue to the more effective use of FloTrac/Vigileo™ system.
-
J Clin Monit Comput · Dec 2013
Validation of the new Complior sensor to record pressure signals non-invasively.
The Complior device (Alam Medical, France) has contributed to the rise of arterial stiffness as a measure of cardiovascular risk. In its latest version (Complior Analyse) the sensor records pressure instead of distension waveforms thus allowing the measurement of central pressure and pulse wave analysis. The aim of our study was to verify that the new sensor measures pressure waveforms accurately in both time and frequency domain. ⋯ These differences were of the same magnitude as the beat-to-beat variation of the form factor (3.3 %) and of the absolute area (3.1 mmHg·s(-1)), respectively. The second systolic peak was detectable in 4 subjects, with no statistical difference between invasive and non-invasive values. The new pressure sensor of the Complior Analyse device recorded pressure waveforms accurately and could be used to perform pressure wave analysis.
-
J Clin Monit Comput · Dec 2013
Case ReportsMethohexital in total intravenous anesthesia during intraoperative neurophysiological monitoring.
Total intravenous anesthesia (TIVA) is usually recommended during spinal surgery when transcranial motor evoked potentials (tcMEPs) are used to monitor. A shortage of propofol has prompted a search for an alternative sedative-hypnotic agent. We explored the use of methohexital as an alternative. ⋯ TcMEPs and somatosensory evoked potentials were acquired to monitor neurological function and electroencephalogram was used to titrate the methohexital dose. Two cases are presented in which the anesthesia and monitoring that was provided were successful. These cases indicate that methohexital can be a suitable alternative to propofol in some patients.