Related Experiment Video
Updated: Feb 7, 2026
Evaluation of Respiratory System Mechanics in Mice using the Forced Oscillation Technique
Published on: May 15, 2013
The importance of sensor contacting force for predicting fluid responsiveness in children using respiratory
Jonghyun Park1, Seungman Yang1, Ji-Hyun Lee2
1Interdisciplinary Program for Bioengineering, Seoul National University Graduate School, Seoul, South Korea.
Insights
Optimizing contacting force improves the accuracy of respiratory variations in pulse oximetry plethysmographic waveform amplitude (ΔPOP) for predicting fluid responsiveness in children. Controlled force enhances ΔPOP
Area of Science:
- Pediatric critical care medicine
- Anesthesiology
- Cardiopulmonary physiology
Background:
- Predicting fluid responsiveness is vital for effective fluid management in critically ill children.
- Respiratory variations in pulse oximetry plethysmographic waveform amplitude (ΔPOP) are explored as a non-invasive method.
- The reliability of ΔPOP in pediatric patients is questioned due to potential influences like sensor contacting force.
Purpose of the Study:
- To investigate the impact of varying sensor contacting forces on the accuracy of ΔPOP in predicting fluid responsiveness in mechanically ventilated children.
- To determine the optimal contacting force range for reliable ΔPOP measurements in this population.
- To compare the predictive performance of ΔPOP with other respiratory variation indices like pulse pressure variation (PPV) and ΔVpeak.
Main Methods:
- A study involving 43 mechanically ventilated children (1 month - 5 years) was conducted.
- ΔPOP was measured across five distinct contacting force groups (0-0.3N to 1.2-1.5N) and with individually adjusted force.
- Fluid responsiveness was defined as a >15% increase in stroke volume index (SVI) post-volume expansion; PPV and ΔVpeak were also recorded.
Main Results:
- Significant differences between fluid responders and non-responders were observed only with ΔPOP at 0.9-1.2N contacting force (P=0.002) and individually adjusted force (P<0.000).
- Other contacting force groups showed no significant predictive ability for ΔPOP.
- ΔVpeak accurately predicted fluid responsiveness (P=0.008), while PPV did not.
Conclusions:
- The predictive capability of ΔPOP for fluid responsiveness in mechanically ventilated children is highly dependent on the applied sensor contacting force.
- Controlled and adequate contacting force significantly enhances the reliability of ΔPOP as a fluid responsiveness indicator.
- Optimizing contacting force is crucial for improving the clinical utility of ΔPOP in pediatric fluid management.
Abstract:
Predicting fluid responsiveness is crucial for adequate fluid management. Respiratory variations in pulse oximetry plethysmographic waveform amplitude (ΔPOP) are used to predict fluid responsiveness, but show inconsistent results when used for children. Contacting force between the measurement site and sensor can affect the ΔPOP value, thereby hindering its reliability as an indicator. We studied the influence of contacting force on the efficacy of ΔPOP as a fluid responsiveness indicator in children. In total, 43 mechanically ventilated children aged 1 month-5 years were studied. After anesthetic induction, mechanical ventilation began with a tidal volume of 10 ml/kg. ΔPOP was calculated for five different contacting force groups (0-0.3N, 0.3-0.6N, 0.6-0.9N, 0.9-1.2N, and 1.2-1.5N) and individually adjusted contacting force. Pulse pressure variation (PPV), and ΔVpeak were recorded before and after volume expansion. Subjects were considered as fluid responders if volume expansion increased the stroke volume index (SVI) by > 15%. Data from 38 patients were finally analyzed. A significant difference between the responders and non-responders was found only in ΔPOPs at 0.9-1.2N contacting force (P = 0.002) and individually adjusted contacting force (P < 0.000), while other contacting force groups did not show significant differences. ΔVpeak predicted a 15% increase in SVI (P = 0.008), whereas PPV did not. The ability of ΔPOP to predict fluid responsiveness depends on the contacting force in mechanically ventilated children. When contacting force is controlled to an adequate degree, the ability of ΔPOP to predict fluid responsiveness can be improved.
Related Concept Videos
01:24Pulse Oximetry
Purpose
Average SpO2 values are greater than 95%. If the readings fall below 90%, it indicates that...
01:11Pressure Variation in a Fluid at Rest
When measuring pressure at two different levels within the fluid, the difference in...
01:14What is Variation?
The range, standard deviation, standard error, and variance are the different measures of variation.
Range: The range is the difference between its maximum and...
01:13Cell-matrix's Response to Mechanical Forces
Anchoring junctions mechanically attach a cell to the...
01:07Effective Value of a Periodic Waveform
The effective value of a periodic current represents the direct current (DC) that conveys the same average power to a resistor as the periodic current itself. This concept is crucial when assessing AC circuits. To determine the...
01:19Variation
When independent and dependent variables are plotted on a scatter plot, the slope of a line is a value that describes the rate of change between the two...