Sublingual microcirculation in patients with intra-abdominal hypertension: A pilot study in 15 critically ill patients

Abstract

PurposeThe purpose of the study is to clarify whether increased intra-abdominal pressure (IAP) is associated with sublingual microcirculatory alterations in intensive care patients. MethodsFifteen adult, mechanically ventilated patients were included if their IAP was at least 12 mm Hg for at least 12 hours within the first 3 days after admission to the intensive care unit. Sublingual sidestream dark field (SDF) images were recorded twice a day for 7 days. ResultsMedian (interquartile range) IAP at inclusion was 14.5 (12.5-16.0) mm Hg. The total vascular density of small vessels at the sublingual area was 13.1 (10.6-14.3) per square millimeter at baseline; the proportion of perfused vessels, 78.9% (69.6%-86.2%); and perfused vessels density, 12.4 (10.8-13.8) per square millimeter. The calculated indices suggested relatively good blood flow in the capillaries, with a De Backer score of 9.0 (8.3-10.2) and a microvascular blood flow of 3.0 (2.9-3.0). Blood flow heterogeneity index was 0.3 (0.1-0.5) at study entry. Despite that IAP, vasopressors dose, and arterial lactate decreased significantly over time, no significant changes were observed in sublingual microvascular density or blood flow. Weak correlations of microvascular blood flow (positive) and heterogeneity index (negative) were detected with both mean arterial pressure and abdominal perfusion pressure. ConclusionsNeither grade I or II intra-abdominal hypertension (IAP from 12 to 18 mm Hg) is associated with significant changes of sublingual microcirculation in intensive care patients. Correlation analysis indicates better microvascular blood flow at higher mean arterial pressure and abdominal perfusion pressure levels.