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Measurement of cardiac output in children by pressure-recording analytical method
Javier Urbano1, Jorge López, Rafael González
1Pediatric Intensive Care Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria del, Hospital General Universitario Gregorio Marañón de Madrid, Madrid, Spain.
Insights
Pressure-Recording Analytical Method (PRAM) software frequently provided cardiac index (CI) measurements outside normal ranges in stable pediatric patients. Factors like patient age, weight, catheter site, and dicrotic notch presence influenced these PRAM CI values.
Area of Science:
- Pediatric Critical Care Medicine
- Hemodynamic Monitoring
- Cardiovascular Physiology
Background:
- Accurate cardiac index (CI) measurement is crucial for managing critically ill children.
- The Pressure-Recording Analytical Method (PRAM) is a non-invasive technique for CI assessment.
- Previous studies have not fully elucidated PRAM's accuracy in stable pediatric populations.
Purpose of the Study:
- To evaluate the accuracy of two PRAM software versions (v.1 and v.2) for measuring CI in hemodynamically stable critically ill children.
- To identify factors influencing PRAM-derived CI values in this patient group.
Main Methods:
- Ninety-five CI measurements using PRAM were analyzed in 47 pediatric patients (1-168 months).
- Patients were hemodynamically stable at the time of measurement.
- Data were collected on patient age, weight, catheter type and location, and presence of a dicrotic notch on the waveform.
Main Results:
- Over half (53.7%) of PRAM CI measurements fell outside the normal range (3-5 L/min/m²).
- Software version 2 showed a trend towards more measurements outside normal limits compared to version 1 (69.2% vs. 47.8%, p=0.062).
- Lower CI values were associated with a visible dicrotic notch and radial artery catheterization; higher values were seen in infants (<12 months) and those <10 kg.
Conclusions:
- A significant proportion of PRAM-generated CI measurements were outside normal limits in stable, critically ill children.
- PRAM CI measurements can be influenced by patient age, weight, catheter insertion site, and waveform characteristics (dicrotic notch).
- Further validation and refinement of PRAM software are needed for reliable pediatric CI monitoring.
Abstract:
We evaluated two pressure-recording analytical method (PRAM) software versions (v.1 and v.2) to measure cardiac index (CI) in hemodynamically stable critically ill children and investigate factors that influence PRAM values. The working hypothesis was that PRAM CI measurements would stay within normal limits in hemodynamically stable patients. Ninety-five CI PRAM measurements were analyzed in 47 patients aged 1-168 months. Mean CI was 4.1 ± 1.4 L/min/m(2) (range 2.0-7.0). CI was outside limits defined as normal (3-5 L/min/m(2)) in 53.7% of measurements (47.8% with software v.1 and 69.2% with software v.2, p = 0.062). Moreover, 14.7% of measurements were below 2.5 L/min/m(2), and 13.6% were above 6 L/min/m(2). CI was significantly lower in patients with a clearly visible dicrotic notch than in those without (3.7 vs. 4.6 L/min/m(2), p = 0.004) and in children with a radial arterial catheter (3.5 L/min/m(2)) than in those with a brachial (4.4 L/min/m(2), p = 0.021) or femoral catheter (4.7 L/min/m(2), p = 0.005). By contrast, CI was significantly higher in children under 12 months (4.2 vs. 3.6 L/min/m(2), p = 0.034) and weighing under 10 kg (4.2 vs. 3.6 L/min/m(2), p = 0.026). No significant differences were observed between cardiac surgery patients and the rest of children. A high percentage of CI measurements registered by PRAM were outside normal limits in hemodynamically stable, critically ill children. CI measured by PRAM may be influenced by the age, weight, location of catheter, and presence of a dicrotic notch.
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