[A correlation of pulse pressure and prognosis of refractory septic shock patients].

Objective: To explore the correlation of pulse pressure(PP) and outcome in refractory septic shock patients.

Methods: A total of 68 patients with refractory septic shock consecutively admitted in our ICU from January 2012 to December 2012 were retrospectively studied. Hemodynamic data and arterial lactate concentration were collected at the time of admission and 24 hours after admission. The outcome of Day 28 post-diagnosis was also recorded.

Results: (1) Compared with the survivors, heart rate (HR) at 24 hours after admission was higher in non-survivors, while 24 h lactate clearance rate (rLac) was lower in them (P < 0.05). Other hemodynamic parameters showed no difference between the non-survivors and the survivors at 24 hours after admission, including central venous pressure (CVP), mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP), PP, pulse pressure/heart rate (PP/HR), pulse pressure/mean arterial pressure (PP/MAP), pulse pressure/systolic pressure (PP/SBP), pulse pressure/diastolic pressure (PP/DBP), the value of SBP above MAP (SMP)and the value of DBP below MAP (MDP). (2)The mortality rate was higher in the patients with HR ≥ 100 b/min than those with HR<100 b/min, but without statistical significance (56.25% vs 36.11%, P = 0.096). Compared with the survivors, no matter with HR ≥ 100 b/min or HR<100 b/min, lactate (Lac) at the 24 hours after admission was higher in all the non-survivors (P < 0.05), while with lower rLac (P < 0.05). In those with HR ≥ 100 b/min, the following hemodynamic parameters were higher in the non-survivors than in the survivors, including PP, PP/HR, PP/MAP, PP/SBP, PP/DBP, SMP and MDP (all P values<0.05), while no statistical difference was observed in those with HR<100 b/min. (3) The mortality rate showed no statistical difference in those with MAP ≥ 85 mmHg (1 mmHg = 0.133 kPa) and with MAP < 85 mmHg (42.42% vs 48.57%, P = 0.611) . No matter MAP ≥ 85 mmHg or MAP < 85 mmHg, compared with the survivors, all the non-survivors had higher Lac at the 24 hours after admission (P < 0.05), while with lower rLac (P < 0.05). In those with MAP ≥ 85 mmHg, HR was higher in the non-survivors than the survivors (P < 0.05). In those with MAP < 85 mmHg, compared with the survivors, the non-survivors had higher PP, PP/MAP, PP/SBP, PP/DBP, SMP and MDP (P < 0.05), while with lower DBP (P < 0.05).

Conclusion: PP is correlated with the outcome in refractory septic shock patients. When the HR and MAP differ, PP has different effect on the outcome and contributes more to the tissue perfusion and outcome in those with higher HR and lower MAP.