Table 2. Peripheral and cerebral hemodynamic parameters for FLAT (0°) and SIT (30°) head positions for two repeated visits
ParameterVisit 1Visit 2P value (head position effect)P value (visit effect)
5‐min FLAT (0°)5‐min SIT (30°)5‐min FLAT (0°)5‐min SIT (30°)
BP (mmHg)89.1 ± 12.181.8 ± 889.6 ± 11.379.8 ± 11.4<0.0010.39
Heart rate (bpm)65.7 ± 9.965.1 ± 9.765.3 ± 11.365.1 ± 110.420.89
End‐tidal CO2 (mmHg)38.4 ± 4.737.3 ± 4.639.3 ± 339.5 ± 1.70.390.38
CBV (cm·sec−1)53.5 ± 13.651.1 ± 13.8a51.9 ± 12.249.7 ± 12.9b<0.00050.66
CrCP (mmHg)39 ± 10.432.5 ± 9.2a40.1 ± 1132.9 ± 11.4b<0.00050.77
RAP (mmHg·sec·cm−1)0.94 ± 0.311.02 ± 0.320.95 ± 0.270.99 ± 0.320.130.93
ARI5.64 ± 1.425.47 ± 1.16 ± 1.376.12 ± 10.860.1
  • Values are mean ± SD for 5 min segments of data. P values from two‐way ANOVA for the difference between 5‐min FLAT and SIT head positions and between visits 1 and 2. BP, blood pressure; bpm, beats per minute; CBV, cerebral blood velocity; CrCP, critical closing pressure; RAP, resistance area product; ARI, autoregulation index.

  • a Tukey post hoc compared to FLAT head position P < 0.05 in visit 1.

  • b Tukey post hoc compared to FLAT head position P < 0.05 in visit 2.