Fig 1.
Cohort inclusion and exclusion flow diagram.
Table 1.
Patient demographic and clinical characteristics.
Fig 2.
Log heart rate variability over time from PICU admission for first and last 24 hours of PICU stay.
Mean HRV for A) SDNN, B) RMSSD, and C) pNN50 displayed from time of PICU admission with HRV from the first 24 hours of PICU stay in the left panel and the last 24 hours in the right panel of each graph. Loess Curves are superimposed.
Table 2.
Mixed models evaluating log of the three heart rate variability metrics in the first compared to the last 24 hours of PICU stay.
Fig 3.
Mixed effects model demonstrating predicted average log heart rate variability in the first vs. last 24 hours of PICU stay.
The predicted log HRV is demonstrated for each patient (colored lines) as well as the average value (solid black line) in the first 24 hours of PICU admission (left panel) vs. last 24 hours (right panel). Each colored line indicates an individual patient’s conditional predicted HRV accounting for random effects with the solid black line representing the marginal predicted mean accounting only for fixed effects. Hour represents the number of hours that have passed after admission (left panel) or number of hours that have passed in the 24 hours prior to discharge (right panel). Hour 0 in the first period is the first measurement upon admission; hour 0 in last period is 24 hours before discharge. Mixed models demonstrated that all three measures of HRV were significantly lower during the first 24 hours compared to the last 24 hours of PICU admission (p<0.001).
Fig 4.
Mean heart rate variability and PICU Length of stay.
Mean HRV for a) SDNN; b) RMSSD, and c) pNN50 plotted against PICU length of stay the first 24 hours of PICU stay in the left panel and the last 24 hours in the right panel of each graph.