Table 2. Changes in hemodynamic parameters based on PDA.
| Variables | Preterm infants with PDA (n = 25) | Preterm infants without PDA (n = 29) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Pre-caffeine | 1 hr after loading dose | 4 hr after loading dose | P value | Pre-caffeine | 1 hr after loading dose | 4 hr after loading dose | P value | ||
| RVO, mL/kg/min | 235.1 ± 37.2 | 236.9 ± 40.8 | 225.8 ± 36.8 | 0.125 | 218.5 ± 60.1 | 213.4 ± 52.4 | 216.0 ± 63.6 | 0.660 | |
| LVO, mL/kg/min | 214.2 ± 51.4 | 211.4 ± 53.8 | 200.4 ± 47.6b | 0.035a | 177.6 ± 39.6 | 174.4 ± 50.7 | 177.5 ± 60.8 | 0.780 | |
| SVC flow, mL/kg/min | 162.4 ± 50.9 | 153.2 ± 46.2 | 155.0 ± 59.5 | 0.224 | 132.2 ± 31.6 | 133.5 ± 33.9 | 134.8 ± 38.0 | 0.859 | |
| EF, % | 66.9 ± 6.7 | 65.8 ± 5.6 | 65.6 ± 5.0 | 0.520 | 63.8 ± 7.0 | 62.2 ± 6.7 | 62.9 ± 6.1 | 0.195 | |
| SF, % | 34.3 ± 5.1 | 33.4 ± 4.1 | 33.2 ± 3.7 | 0.436 | 31.9 ± 4.7 | 30.8 ± 4.5 | 31.2 ± 4.2 | 0.187 | |
| LA/Ao ratio | 1.34 ± 0.19 | 1.27 ± 0.08b | 1.26 ± 0.11b | 0.014a | 1.26 ± 0.12 | 1.21 ± 0.10 | 1.23 ± 0.11 | 0.070 | |
| PDA | |||||||||
| Diameter, mm | 1.14 ± 0.28 | 1.14 ± 0.26 | 1.05 ± 0.22b | < 0.001a | |||||
| Vmax, m/s | 2.00 ± 0.51 | 2.11 ± 0.49b | 2.25 ± 0.48b | < 0.001a | |||||
| VTI, cm | 67.4 ± 22.9 | 71.6 ± 20.4b | 75.1 ± 19.4b | 0.003a | |||||
| DSV, mL | 0.70 ± 0.37 | 0.74 ± 0.38b | 0.67 ± 0.31 | 0.068 | |||||
| HR, /min | 146.2 ± 9.9 | 148.5 ± 12.4 | 147.2 ± 9.0 | 0.721 | 141.6 ± 14.8 | 141.7 ± 15.8 | 142.4 ± 14.9 | 0.926 | |
| Calculated ductal shunting flowc, mL/min | 101.5 ± 53.1 | 110.0 ± 55.3b | 99.4 ± 45.8 | 0.091 | |||||
| SBP, mmHg | 50.0 ± 7.7 | 51.8 ± 7.4 | 54.2 ± 10.1 | 0.126 | 56.8 ± 10.7 | 60.4 ± 8.6 | 57.3 ± 12.1 | 0.206 | |
| DBP, mmHg | 27.7 ± 5.7 | 31.5 ± 7.4 | 32.5 ± 7.9 | 0.019 | 34.3 ± 7.4 | 35.3 ± 7.5 | 35.0 ± 8.1 | 0.822 | |
| MBP, mmHg | 37.6 ± 8.2 | 39.6 ± 7.3 | 40.8 ± 7.5 | 0.228 | 45.1 ± 9.2 | 44.7 ± 8.4 | 44.9 ± 10.1 | 0.967 | |
PDA = patent ductus arteriosus, RVO = right ventricular output, LVO = left ventricular output, SVC = superior vena cava, EF = ejection fraction, SF = shortening fraction, LA/Ao ratio = left atrial to aortic ratio, Vmax = maximal velocity, VTI = velocity time integral, DSV = ductal shunting volume per beat, HR = heart rate, SBP = systolic blood pressure, DBP = diastolic blood pressure, MBP = mean blood pressure, ANOVA = analysis of variance.
aP < 0.05. P values were calculated by repeated-measures ANOVA comparing caffeine levels before and 1 hour and 4 hours after administration; bP < 0.05. P values were calculated by the paired t-test; cCalculated ductal shunting flow (mL/min) = DSV (mL) × HR (/min).