Volumetric responsiveness of total lung compliance

Objective To investigate the volumetric responsiveness of lung total compliance (C) and the effect of hypertension on its responsiveness.

Methods Sixty-five patients who underwent elective recumbent surgery in Red Cross Hospital of Guangzhou in Guangdong Province were selected as study subjects.C, airway plateau pressure (p_plat), peak airway pressure (p_peak), heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), stroke volume variability (SVV) and stroke volume (SV) of patients were recorded at different time points5 min (t₁), 10 min (t₂), 15 min (t₃), 20 min (t₄), 25 min (t₅), 30 min (t₆)of 30 min after mechanical ventilation.The change of C, SV, SVV (△C, △SV, △SVV) of patients in time periods of T₁(5 to 10 min), T₂(>10 to 15 min), T₃(>15 to 20 min), T₄(>20 to 25min) and T₅(>25 to 30 min) were recorded.The brachial and ankle pulse wave conduction velocity (BaPWV) of hypertensive and non-hypertensive patients was collected by Japanese Kelin arteriosclerosis detector.

Results There were no significant differences in HR, MAP, SVV, SV, CO, p_plat, p_peak and C from t₁ to t₆ time points (P>0.05).The correlation coefficients (r) between △C and △SVV were-0.626, -0.650, -0.676, -0.588, -0.518, respectively, were 0.744, 0.772, 0.785, 0.698 and 0.681, respectively between △C and △SV in all subjects during T₁ to T₅; during T₁ to T₅, the correlations between △C and △SVV, between △C and △SV increased in non-hypertensive subjects, but decreased in hypertensive subjects, the correlations between △C and △SVV or △C and △SV were the strongest during T₃ in both hypertensive and non-hypertensive subjects.BaPWV of hypertensive and non-hypertensive patients showed significant difference (P < 0.05).

Conclusion C has capacity response and hypertension can affect its responsiveness.