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Published on: December 2, 2017
Evaluation of Automated Finger Compression for Capillary Refill Time Measurement in Pediatrics
Amanda J Nickel1, Shen Jiang2, Natalie Napolitano1
1From the Department of Respiratory Care, Children's Hospital of Philadelphia, Philadelphia, PA.
Insights
Automated capillary refill time (CRT) monitoring in children requires precise compression. A pressure of 500 mm Hg with an automated device ensures consistent and reliable CRT measurements for shock assessment.
Area of Science:
- Pediatric Emergency Medicine
- Cardiovascular Physiology
- Medical Device Technology
Background:
- Capillary refill time (CRT) is vital for identifying and monitoring pediatric shock.
- Manual CRT measurement can be inconsistent, impacting patient care.
- Automated systems aim to improve CRT measurement reliability.
Purpose of the Study:
- To determine the optimal compression pressure for an automated CRT monitoring device in children.
- To minimize inconsistency in CRT measurements using an automated compression device.
Main Methods:
- Clinician force data (12.9 N) from manual CRT measurements informed automated device settings.
- An automated device with a force sensor evaluated pressures from 300 to 500 mm Hg.
- Effectiveness was assessed by the elimination of pulsatile blood flow and CRT variance.
Main Results:
- Pressures of 400 and 500 mm Hg effectively eliminated pulsatile blood flow in automated CRT measurements.
- No significant difference in median CRT was observed between 400 mm Hg (1.8) and 500 mm Hg (1.87).
- Automated CRT demonstrated superior consistency at 500 mm Hg (variance 1.35) compared to 400 mm Hg (variance 2.99), with higher intraclass correlation (0.78 vs. 0.56).
Conclusions:
- Automated CRT measurement using 400 or 500 mm Hg is appropriate for pediatric shock assessment.
- 500 mm Hg provides superior consistency and reliability for automated CRT measurements.
- This technology can improve the accuracy of shock monitoring in children.
Objectives:
Early shock reversal is crucial to improve patient outcomes. Capillary refill time (CRT) is clinically important to identify and monitor shock in children but has issues with inconsistency. To minimize inconsistency, we evaluated a CRT monitoring system using an automated compression device. Our objective was to determine proper compression pressure in children.
Methods:
Clinician force for CRT was collected during manual CRT measurement as a reference for automated compression in a previous study (12.9 N, 95% confidence interval, 12.5-13.4; n = 454). An automated compression device with a soft inflation bladder was fitted with a force sensor. We evaluated the effectiveness of the automated pressure to eliminate pulsatile blood flow from the distal phalange. Median and variance of CRT analysis at each pressure was compared.
Results:
A comparison of pressures at 300 to 500 mm Hg on a simulated finger yielded a force of 5 to 10 N, and these pressures were subsequently used for automated compression for CRT. Automated compression was tested in 44 subjects (median age, 33 months; interquartile range [IQR], 14-56 months). At interim analysis of 17 subjects, there was significant difference in the waveform with residual pulsatile blood flow (9/50: 18% at 300 mm Hg, 5/50:10% at 400 mm Hg, 0/51: 0% at 500 mm Hg, P = 0.008). With subsequent enrollment of 27 subjects at 400 and 500 mm Hg, none had residual pulsatile blood flow. There was no difference in the CRT: median 1.8 (IQR, 1.06-2.875) in 400 mm Hg vs median 1.87 (IQR, 1.25-2.8325) in 500 mm Hg, P = 0.81. The variance of CRT was significantly larger in 400 mm Hg: 2.99 in 400 mm Hg vs. 1.35 in 500 mm Hg, P = 0.02, Levene's test. Intraclass correlation coefficient for automated CRT was 0.56 at 400 mm Hg and 0.78 at 500 mm Hg.
Conclusions:
Using clinician CRT measurement data, we determined either 400 or 500 mm Hg is an appropriate pressure for automated CRT, although 500 mm Hg demonstrates superior consistency.
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