Journal of clinical monitoring and computing
-
J Clin Monit Comput · Oct 2016
A validation study of electrical cardiometry in pregnant patients using transthoracic echocardiography as the reference standard.
To validate electrical cardiometry (EC) in pregnant patients using transthoracic echocardiography (TTE) as the reference standard. To improve EC accuracy via a one-time, measurement of left ventricular outflow tract (LVOT) diameter. 44 non-laboring, resting women with singleton, viable pregnancies underwent simultaneous EC and TTE measurements. Data were analyzed using Bland-Altman analysis. ⋯ EC accurately measures heart rate and duration of systole when compared with TTE. Stroke volume measurements correlate but have a high bias and percentage error. Knowledge of LVOT area, by a one-time, measurement with TTE, could improve prediction of stroke volume by EC.
-
J Clin Monit Comput · Oct 2016
Does using two Doppler cardiac output monitors in tandem provide a reliable trend line of changes for validation studies?
The demise of the pulmonary artery catheter as a gold standard in cardiac output measurement has created the need for new standard. Doppler cardiac output can be measured suprasternally (USCOM) and via the oesophagus (CardioQ). Use in tandem they may provide a reliable trend line of cardiac output changes against which new technologies can be assessed. ⋯ The regression line between Doppler methods was offset with a slope of 0.9, thus CardioQ CI readings increased relative to USCOM. Both Doppler methods trended cardiac output reliably. Used in tandem they provide a new standard to assess cardiac output trending.
-
J Clin Monit Comput · Oct 2016
Accuracy of inhaled agent usage displays of automated target control anesthesia machines.
Automated low flow anesthesia machines report how much inhaled anesthetic agent has been used for each anesthetic. We compared these reported values with the amount of agent that had disappeared by weighing the vaporizer/injectors before and after each anesthetic. The vaporizers/injectors of the Aisys, Zeus and FLOW-i were weighed with a high precision weighing scale before and after anesthesia with either desflurane in O2/air or sevoflurane in O2/N2O. ⋯ The differences may be due to either measurement error or cumulative agent display error. The current results can help the researchers decide whether the displayed amounts are accurate enough for their study purposes. The extent to which these discrepancies differ between different units of the same machine remains unstudied.
-
J Clin Monit Comput · Oct 2016
Observational StudyInfluence of different infracardial positions of central venous catheters in hemodynamic monitoring using the transpulmonal thermodilution method.
Hemodynamic measurements are often conducted by the transpulmonary thermodilution (TPTD)-based PiCCO(®)-system. This requires a central-venous (CVC) and a thermistor-tipped arterial catheter, usually placed in the femoral artery. In certain clinical situations, CVC devices have to be placed in the inferior vena cava. ⋯ The LoA yielded at -3.4 and +6.1 mL/kg with a bias of +1.3 mL/kg. Percentage errors revealed clinically acceptable limits for CI and GEDVI, but not for EVLWI. Using TPTD via an infracardial central vein, measurements of CI showed high accuracy and precision while GEDVI measurements were precise with a lower accuracy, irrespective of the position of the infracardial CVC.
-
J Clin Monit Comput · Oct 2016
Evaluation of a fiber-optic technique for recording intramuscular pressure in the human leg.
To evaluate a forward-sensing fiber-optic pressure technique for recording of intramuscular pressure (IMP) in the human leg and investigate factors that may influence IMP measurements used in diagnosing compartment syndromes. IMP in the tibialis anterior muscle was recorded simultaneously by a fiber-optic technique and needle-injection technique in 12 legs of 7 healthy subjects. Both measurement catheters were placed in parallel with the muscle fibers to the same depth, as verified by sonography. ⋯ The fiber-optic technique may be used for IMP measurements in a muscle with both normal and abnormally elevated IMP. It has good dynamic properties allowing for measurement of IMP oscillations. Saline injection used with needle-injection systems to ensure catheter patency compromises IMP readings at least one minute after injection.