Microcirculation during surgery

Abstract

Throughout the long history of surgery, there has been great advancement in the hemodynamic management of surgical patients. Traditionally, hemodynamic management has focused on macrocirculatory monitoring and intervention to maintain appropriate oxygen delivery. However, even after optimization of macro-hemodynamic parameters, microcirculatory dysfunction, which is related to higher postoperative complications, occurs in some patients. Although the clinical significance of microcirculatory dysfunction has been well reported, little is known about interventions to recover microcirculation and prevent microcirculatory dysfunction. This may be at least partly caused by the fact that the feasibility of monitoring tools to evaluate microcirculation is still insufficient for use in routine clinical practice. However, considering recent advancements in these research fields, with more popular use of microcirculation monitoring and more clinical trials, clinicians may better understand and manage microcirculation in surgical patients in the future. In this review, we describe currently available methods for microcirculatory evaluation. The current knowledge on the clinical relevance of microcirculatory alterations has been summarized based on previous studies in various clinical settings. In the latter part, pharmacological and clinical interventions to improve or restore microcirculation are also presented.

Monitoring of the microcirculation in children undergoing major abdominal and thoracic surgery: A pilot study

“…To assess the state of the microcirculation and organ perfusion, surrogate parameters such as capillary refill time, urine production and serum lactate levels are used, however these parameters are confounded by various factors thus limiting their diagnostic value [ 1 ]. The development of Handheld Vital Microscopy (HVM), has enabled direct visualization of microvessels in the skin and mucous membranes allowing microcirculatory monitoring during surgery [ 9 ]. In children, HVM has been successfully applied to evaluate microvessel density and blood flow as well as endothelial glycocalyx in acute and chronic conditions such as sepsis, respiratory failure and diabetes mellitus [ 10–12 ].…”

Impaired Capillary Recruitment Capacity in Obesity: A Subgroup Analysis of Prospective Observational Study on Anesthesia Effects

“…To guarantee the sufficient delivery of nutrients to tissues – a determinant of cellular viability – both macro- and microcirculatory systems must function optimally [ 3 , 4 ]. Given the limited availability of monitoring tools for assessing microcirculation, the predominant focus of perioperative hemodynamic management has been the enhancement of microcirculatory parameters [ 4 ]. Macrohemodynamic parameters should be considered indicators of tissue perfusion, not measurements.…”

“…Macrohemodynamic parameters should be considered indicators of tissue perfusion, not measurements. Even when macrocirculatory indicators are within the standard range, the potential for undetected microcirculatory dysfunction remains [ 4 ].…”

“…Within the context of microcirculatory function analysis, parameters dynamically ascertained through alterations in tissue oxygen saturation (StO 2 ), as derived from near-infrared spectroscopy (NIRS) during temporary occlusion of blood flow (vascular occlusion tests [VOTs]), are preferred because of their noninvasiveness, cost-effectiveness, and high reproducibility [ 4 – 6 ]. NIRS provides continuous StO 2 measurements by exploiting the different absorption frequencies of oxygenated and deoxygenated hemoglobin [ 7 ].…”

Characteristics of sublingual microcirculatory changes during the early postoperative period following cardiopulmonary bypass-assisted cardiac surgery—a prospective cohort study

“…Persistent microcirculatory dysfunction is the main mechanism of tissue oxygenation failure and early organ dysfunction, which have a significant impact on the prognosis of patients. Studies have reported that extensive microcirculatory changes occur after cardiac surgery (1)(2)(3)(4). The changes in microcirculation after cardiac surgery are related to potential heart disease or cardiogenic shock, anesthesia, and surgical procedures, and the impact of cardiopulmonary bypass (CPB) on microcirculation should not be overlooked.…”