Microvascular reactivity and clinical outcomes in cardiac surgery

Abstract

IntroductionMicrovascular reactivity is decreased in patients with septic shock; this is associated with worse clinical outcomes. The objectives of the present study were to investigate microvascular reactivity in cardiac surgery patients and to assess any association with clinical outcomes.MethodsWe retrospectively analyzed a prospectively collected registry. In total, 254 consecutive adult patients undergoing cardiac and thoracic aortic surgeries from January 2013 through May 2014 were analyzed. We performed a vascular occlusion test (VOT) by using near-infrared spectroscopy to measure microvascular reactivity. VOT was performed three times per patient: prior to the induction of anesthesia, at the end of surgery, and on postoperative day 1. The primary endpoint was a composite of major adverse complications, including death, myocardial infarction, acute kidney injury, acute respiratory distress syndrome, and persistent cardiogenic shock.ResultsVOT recovery slope decreased during the surgery. VOT recovery slope on postoperative day 1 was significantly lower in patients with composite complications than those without (3.1 ± 1.6 versus 4.0 ± 1.5 %/s, P = 0.001), although conventional hemodynamic values, such as cardiac output and blood pressure, did not differ between the groups. On multivariable regression and linear analyses, low VOT recovery slope on postoperative day 1 was associated with increases of composite complications (odds ratio 0.742; 95 % confidence interval (CI) 0.584 to 0.943; P = 0.015) and hospital length of stay (regression coefficient (B) −1.276; 95 % CI −2.440 to −0.112; P = 0.032).ConclusionMicrovascular reactivity largely recovered on postoperative day 1 in the patients without composite complications, but this restoration was attenuated in patients with composite complications.Trial registrationClinicalTrials.gov NCT01713192. Registered 22 October 2012.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-015-1025-3) contains supplementary material, which is available to authorized users.

Microvascular Responsiveness to Pulsatile and Nonpulsatile Flow During Cardiopulmonary Bypass

“…With the use of NIRS measurements of StO 2 and the VOT, we also report improved microcirculatory vasoreactivity in patients undergoing pulsatile CPB. The decrease in reperfusion slopes in the nonpulsatile group is likely due to vasomotor dysfunction similar to those measured in previous studies [9,10]. Our study indicates that nonpulsatile flow is associated with statistically significant microvascular alterations, impaired vasoreactivity, and increased postoperative serum creatinine levels, whereas pulsatile flow resulted in a relative maintenance of homeostasis.…”

“…Methods. A prospective, randomized cohort study of 20 high-risk cardiac surgical patients undergoing pulsatile (n [ 10) or nonpulsatile (n [ 10) flow during CPB was conducted. Changes in sublingual mucosal microcirculation were assessed with orthogonal polarization spectral imaging along with near-infrared spectroscopic indices of thenar muscle tissue oxygen saturation (StO 2 ) and its recovery during a vascular occlusion test at the following time points: baseline (T 0 ), 30 minutes on CPB (T 1 ), 90 minutes on CPB (T 2 ), 1 hour after CPB (T 3 ), and 24 hours after CPB (T 4 ).…”

Dynamic changes of angiopoietins and endothelial nitric oxide supply during fluid resuscitation for major gyn-oncological surgery: a prospective observation

“…In particular, parameters indicating disturbed capillary recruitment and endothelial NO bioavailability such as the recovery time and the reactive hyperemia following reperfusion were associated with individually increased serum ANG-2 levels in our patients. Impaired microvascular function was shown to be a marker as well as a determinant of a worsened clinical outcome following surgery [6,7,33]. In our cohort, increased serum ANG-2 as well as concomitantly reduced microvascular function were associated with postoperatively elevated lactate levels, being indicative of an impaired capillary perfusion during surgery.…”

“…Assessment of microvascular reactivity was performed similar to what was described by Kim et al [6]. Following induction of anesthesia, a near-infrared spectroscopy (NIRS) sensor (Nonin Medical, Inc., Plymouth, MN, USA) was placed on the patient's left forearm and connected to a Nonin 7600 4-Channel Regional Oximeter (Nonin Medical, Inc.) to measure muscle tissue oxygen saturation (S t O 2 ).…”

“…However, microvascular function has been shown to deteriorate during major gyn-oncological abdominal surgery despite the use of GDT [5]. Impaired vascular function, in turn, is one determinant of poor outcome after surgery [6,7].…”