Journal of clinical monitoring and computing
-
J Clin Monit Comput · Apr 2012
Comparative StudyNoninvasive continuous beat-to-beat radial artery pressure via TL-200 applanation tonometry.
The Tensys TL-200(®) noninvasive beat-to-beat blood pressure (BP) monitor displays continuous radial artery waveform as well as systolic, mean and diastolic BP from a pressure sensor directly over the radial artery at the wrist. It locates the site of maximal radial pulse signal, determines mean BP from maximal pulse waveform amplitude at optimal artery compression and then derives systolic and diastolic BP. We performed a cross-sectional study of TL-200 BP comparisons with contralateral invasive radial artery (A-Line) BP values in 19 subjects during an average 2.5 h of general anesthesia for a wide range of surgical procedures. ⋯ Coefficients of determination for TL-200 and A-Line BP regression were r² = 0.86 for systolic, r² = 0.86 for mean, and r² = 80 for diastolic BP, respectively, with no apparent change in correlation at low or high BP. Bland-Altman analysis suggested satisfactory agreement between TL-200 noninvasive beat-to-beat BP and invasive A-Line BP. Paired TL-200/A-Line BP comparisons showed a high coefficient of determination.
-
J Clin Monit Comput · Apr 2012
Comparative StudyImpact of non invasive and beat-to-beat arterial pressure monitoring on intraoperative hemodynamic management.
The Nexfin device allows for non-invasive beat-to-beat blood pressure monitoring (BP(NXF)). Perioperative hypotension and hypertension have been shown to be associated with poor clinical outcomes. The goal of the present study was to assess the ability of this device to decrease the duration of significant intraoperative hypo- or hypertension compared to standard BP monitoring by cuff (BP(CUFF)). ⋯ If hemodynamic changes seen by SBP(NXF) were appropriately treated, an average of 7 ± 1 min/h of hypotension time, 7 ± 2 min/h of hypertension time and 14 ± 3 min per hour of hypo- or hypertension time may have been identified. The Nexfin BP has the potential to decrease the time of hypotension and hypertension compared to conventional intermittent BP(CUFF) monitoring. Therefore, this device has the potential to positively impact clinical outcomes.
-
J Clin Monit Comput · Apr 2012
Comparative StudyA comparative study of pulse rate variability and heart rate variability in healthy subjects.
Both heart rate variability (HRV) and pulse rate variability (PRV) are noninvasive means for the assessment of autonomic nervous control of the heart. However, it is not settled whether or not the PRV obtained from either hand can be the surrogate of HRV. The HRV measures obtained from electrocardiographic signals and the PRV measures obtained from the pulse waves recorded from the index fingers of both hands were compared in normal subjects by using linear regression analysis and Bland and Altman method. ⋯ The PRV of either hand is close to, but not the same as the HRV in healthy subjects. The HRV, right PRV and left PRV are not surrogates of one another in normal subjects except heart rate and ULFP. Since HRV is generally accepted as the standard method for the assessment of the autonomic nervous modulation of a subject, the PRV of either hand may not be suitable for the assessment of the cardiac autonomic nervous modulation of the subject.
-
J Clin Monit Comput · Apr 2012
Comparative StudyAbility of the Masimo pulse CO-Oximeter to detect changes in hemoglobin.
The decision to administer blood products is complex and multifactorial. Accurate assessment of the concentration of hemoglobin [Hgb] is a key component of this evaluation. Recently a noninvasive method of continuously measuring hemoglobin (SpHb) has become available with multi-wavelength Pulse CO-Oximetry. ⋯ Four quadrant plot analysis revealed 94% of data within the quadrants associated with the correct direction change, and 90% of data points lay within the analysis bounds proposed by Critchley. Pulse CO-Oximetry offers an acceptable trend monitor in patients undergoing major spine surgery. Future work should explore the ability of this device to detect large changes in hemoglobin, as well as its applicability in additional surgical and non-surgical patient populations.
-
J Clin Monit Comput · Apr 2012
Comparative StudyPulse-plethysmographic variables in hemodynamic assessment during mannitol infusion.
Plethysmographic signal using pulse oximetry may be used to assess fluid status of patients during surgery as it resembles arterial pressure waveform. This will avoid placement of invasive arterial lines. This study was designed to find out whether intravascular volume changes induced by mannitol bolus in neurosurgical patients are detected by variations in arterial pressure and plethysmographic waveforms and also to assess the strength of correlation between different variables derived from these two waveforms. ⋯ The correlation between ∆SPV-∆Pl-PV, ∆PPV-∆Pl-AV and ∆SPV-∆BP-Pleth time lag were significant (r = 0.3; P < 0.01). SPV and time lag had no significant interaction. Pl-PV correlates well with SPV following mannitol infusion and can be used as an alternative to SPV. (BP-Pleth) time-lag promises to be an important parameter in assessing the state of peripheral vascular resistance and deserves further investigation.