A high mean arterial pressure target is associated with improved microcirculation in septic shock patients with previous hypertension: a prospective open label study

INTRODUCTION The effect of mean arterial pressure titration to a higher level on microcirculation in septic shock patients with previous hypertension remains unknown. Our goal is to assess the effect of mean arterial pressure titration to a higher level on microcirculation in hypertensive septic shock patients. METHODS This is a single-center, open-label study. Hypertensive patients with septic shock for less than 24 hours after adequate fluid resuscitation and requiring norepinephrine to maintain a mean arterial pressure of 65 mmHg were enrolled. Mean arterial pressure was then titrated by norepinephrine from 65 mmHg to the normal level of the patient. In addition to hemodynamic variables, sublingual microcirculation was evaluated by sidestream dark field imaging. RESULTS Nineteen patients were enrolled in the study. Increasing mean arterial pressure from 65 mmHg to normal levels was associated with increased central venous pressure (from 11 ± 4 to 13 ± 4 mmHg, P = 0.002), cardiac output (from 5.4 ± 1.4 to 6.4 ± 2.1 l/minute, P = 0.001), and central venous oxygen saturation (from 81 ± 7 to 83 ± 7%, P = 0.001). There were significant increases in small perfused vessel density (from 10.96 ± 2.98 to 11.99 ± 2.55 vessels/mm(2), P = 0.009), proportion of small perfused vessels (from 85 ± 18 to 92 ± 14%, P = 0.002), and small microvascular flow index (from 2.45 ± 0.61 to 2.80 ± 0.68, P = 0.009) when compared with a mean arterial pressure of 65 mmHg. CONCLUSIONS Increasing mean arterial pressure from 65 mmHg to normal levels is associated with improved microcirculation in hypertensive septic shock patients. TRIAL REGISTRATION Clinicaltrials.gov: NCT01443494; registered 28 September 2011.