• capillary density
• capillary diameter
• capillary perfusion
• cardiac output
• gestational hypertension disorder
• hypertension
• maternal hemodynamics
• microcirculation
• nailfold video capillaroscopy
• preeclampsia
• systemic circulation
• vascular resistance

• fluid balance
• kidney
• mean arterial pressure
• urine output

• Humans
• Critical Illness
• Retrospective Studies
• Male
• Female
• Middle Aged
• Arterial Pressure/drug effects
• Arterial Pressure/physiology
• Aged
• Intensive Care Units
• Acute Kidney Injury/physiopathology
• Acute Kidney Injury/urine
• Acute Kidney Injury/diagnosis
• Norepinephrine/urine
• Urination/drug effects
• Urination/physiology

• Hand-held intravital video microscopy
• Hemodynamic monitoring
• Intensive care
• Microcirculation
• Shock

• Acute kidney injury
• Acute lung injury
• Inflammation
• Macrophage
• Sepsis
• Sepsis-associated encephalopathy

• Animals
• Sepsis/drug therapy
• Mice
• Humans
• RAW 264.7 Cells
• Macrophages/drug effects
• Macrophages/metabolism
• Male
• Guanine Nucleotide Exchange Factors/metabolism
• Catechin/pharmacology
• Multiple Organ Failure/drug therapy
• Molecular Docking Simulation
• Kidney/drug effects
• Mice, Inbred C57BL
• Disease Models, Animal
• Lung/drug effects

• sepsis
• glycosaminoglycans
• thrombosis
• inflammation
• detection methods

• Humans
• Sepsis/blood
• Sepsis/complications
• Glycosaminoglycans/blood
• Blood Coagulation
• Animals
• Blood Platelets/metabolism
• Microvessels
• Signal Transduction
• Inflammation/blood
• Microcirculation
• Thrombosis/blood

• COVID-19
• DTPM
• ICU
• capillary refill time
• infrared camera
• microcirculation
• oxygenation ratio
• perfusion

• 11/W/2023 Polish Ministry of Education and Science

• anaesthesia
• blood flow
• haemodynamic coherence
• haemodynamic monitoring
• sublingual microcirculation
• surgery
• tissue perfusion
• vessel density

• Humans
• Microcirculation
• Perioperative Medicine
• Mouth Floor/blood supply
• Cardiac Surgical Procedures
• Oxygen/pharmacology

• Cardiac Surgery
• Congenital Heart Disease
• Optical coherence tomography angiography
• Perioperative outcomes
• Retinal vessel density

• Humans
• Adult
• Fluorescein Angiography/methods
• Microcirculation
• Prospective Studies
• Retina
• Cardiac Surgical Procedures
• Tomography, Optical Coherence/methods

• 2020XXG007 Project of Special Research on Cardiovascular Diseases
• Project of Special Research on Cardiovascular Diseases

• Microcirculation
• general anesthesia
• lidocaine
• sidestream dark-field imaging
• vascular occlusion test
• vessel density

• Humans
• Infusions, Intravenous
• Microcirculation/physiology
• Lidocaine/pharmacology
• Pilot Projects
• Prospective Studies
• Mouth Floor/blood supply
• Postoperative Complications/prevention & control

• Acute heart failure
• Cardiogenic shock
• Microcirculation
• Perfusion

• CSTO 160444 Compagnia di San Paolo

• cardiac surgery
• intensive care medicine
• left ventricular assist device
• metabolic and hemodynamic parameters
• mitochondrial dysfunction
• oxygen consumption
• oxygen delivery

• Humans
• Shock, Cardiogenic
• Microcirculation
• Prospective Studies
• Hemodynamics
• Oxygen

• Heart and Stroke Foundation of Canada National

• Cardiogenic shock
• ECMO flow
• Extracorporeal membrane oxygenation
• Mechanical ventilation
• Outcome

Purpose: Target temperature management (TTM) is often used in patients after cardiac arrest, but the effects of cooling on cerebral microcirculation, oxygenation and metabolism are poorly understood. We studied the time course of these variables in a healthy swine model.Methods: Fifteen invasively monitored, mechanically ventilated pigs were allocated to sham procedure (normothermia, NT; n = 5), cooling (hypothermia, HT, n = 5) or cooling with controlled oxygenation (HT-Oxy, n = 5). Cooling was induced by cold intravenous saline infusion, ice packs and nasal cooling to achieve a body temperature of 33–35 °C. After 6 h, animals were rewarmed to baseline temperature (within 5 h). The cerebral microvascular network was evaluated (at baseline and 2, 7 and 12 h thereafter) using sidestream dark-field (SDF) video-microscopy. Cerebral blood flow (laser Doppler MNP100XP, Oxyflow, Oxford Optronix, Oxford, UK), oxygenation (PbtO₂, Licox catheter, Integra Lifesciences, USA) and lactate/pyruvate ratio (LPR) using brain microdialysis (CMA, Stockholm, Sweden) were measured hourly. Results: In HT animals, cerebral functional capillary density (FCD) and proportion of small-perfused vessels (PSPV) significantly decreased over time during the cooling phase; concomitantly, PbtO₂ increased and LPR decreased. After rewarming, all microcirculatory variables returned to normal values, except LPR, which increased during the rewarming phase in the two groups subjected to HT when compared to the group maintained at normothermia. Conclusions: In healthy animals, TTM can be associated with alterations in cerebral microcirculation during cooling and altered metabolism at rewarming.

• brain metabolism
• cerebral oxygenation
• hypothermia
• lactate
• microvascular flow

• ephedrine
• laparoscopic rectal cancer
• phenylephrine
• sublingual microcirculation
• surgery

• AR-PAM
• OR-PAM
• microcirculation imaging
• microvasculature
• photoacoustic imaging

• Microcirculation
• Photoacoustic Techniques/methods
• Diagnostic Imaging
• Microvessels/physiology
• Hemoglobins/metabolism

• R01 NS078168 NINDS NIH HHS

• Anesthesia, General
• Hemodynamics/physiology
• Humans
• Microcirculation/physiology
• Perfusion
• Surgical Wound

• Biomarkers
• Cardiogenic shock
• Inflammation
• Microvasculature

• Humans
• Percutaneous Coronary Intervention
• Prognosis
• Shock, Cardiogenic/etiology
• Shock, Cardiogenic/therapy
• Treatment Outcome

Ensuring and maintaining adequate tissue oxygenation at the microcirculatory level might be considered the holy grail of optimal hemodynamic patient management. However, in clinical practice we usually focus on macro-hemodynamic variables such as blood pressure, heart rate, and sometimes cardiac output. Other macro-hemodynamic variables like pulse pressure or stroke volume variation are additionally used as markers of fluid responsiveness. In recent years, an increasing number of technological devices assessing tissue oxygenation or microcirculatory blood flow have been developed and validated, and some of them have already been incorporated into clinical practice. In this review, we will summarize recent research findings on this topic as published in the last 2 years in the Journal of Clinical Monitoring and Computing (JCMC). While some techniques are already currently used as routine monitoring (e.g. cerebral oxygenation using near-infrared spectroscopy (NIRS)), others still have to find their way into clinical practice. Therefore, further research is needed, particularly regarding outcome measures and cost-effectiveness, since introducing new technology is always expensive and should be balanced by downstream savings. The JCMC is glad to provide a platform for such research.

• Microcirculation
• Monitoring
• Near-infrared spectroscopy
• Plethysmography
• Tissue oxygenation
• Tissue perfusion

• experimental models of disease
• cardiovascular models

Background: Microcirculatory changes in congenital heart disease (CHD) patients undergoing cardiac surgery are not fully understood. We aimed to investigate the changes of retinal microcirculation in CHD patients after cardiac surgery by optical coherence tomography angiography (OCTA) and explore the association between retinal microcirculation and surgical outcome.

Methods: This prospective observational study consisted of 71 CHD patients aged ≥6 years undergoing cardiac surgery including 19 cyanotic CHD (CCHD) and 52 acyanotic CHD (ACHD). Optical coherence tomography angiography (OCTA) was used to measure vessel density (VD) and capillary density (CD) of radial peripapillary capillary (RPC) and peripapillary, VD of superficial capillary plexus (SCP) and deep capillary plexus (DCP), thickness of retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) preoperatively and 1 month postoperatively. Transthoracic echocardiography was conducted to measure macrocirculation.

Results: In CCHD patients, VD and CD of RPC and peripapillary increased postoperatively (all P < 0.05). In ACHD patients, VD of peripapillary, CD of RPC and peripapillary, and RNFL thickness increased postoperatively (all P < 0.05). VD of SCP and DCP, and GCC thickness did not change significantly in CHD patients after surgery. Lower preoperative retinal microvascular density was associated with longer cardiopulmonary bypass (CPB) time and postoperative length of stay (PLOS). No correlation was found between microcirculatory and macrohemodynamic parameters (all P > 0.05).

Conclusions: Improved retinal microcirculation was observed after congenital cardiac surgery and impaired preoperative retinal microvasculature was associated with prolonged CPB time and PLOS, which might provide potential information about the outcome of congenital cardiac surgery.

• cardiac surgery
• congenital heart disease
• microcirculation
• optical coherence tomography angiography
• retinal vessel density

• Animals
• Digestive System Surgical Procedures/veterinary
• Hemodynamics
• Horses
• Microcirculation
• Microscopy, Video/veterinary
• Mouth Floor/surgery

• canine
• dehydration
• hypovolemia
• shock

Fluid selection and administration during shock is typically guided by consideration of macrovascular abnormalities and resuscitative targets (perfusion parameters, heart rate, blood pressure, cardiac output). However, the microcirculatory unit (comprised of arterioles, true capillaries, and venules) is vital for the effective delivery of oxygen and nutrients to cells and removal of waste products from the tissue beds. Given that the microcirculation is subject to both systemic and local control, there is potential for functional changes and impacts on tissue perfusion that are not reflected by macrocirculatory parameters. This chapter will present an overview of the structure, function and regulation of the microcirculation and endothelial surface layer in health and shock states such as trauma, hemorrhage and sepsis. This will set the stage for consideration of how these microcirculatory characteristics, and the potential disconnect between micro- and macrovascular perfusion, may affect decisions related to acute fluid therapy (fluid type, amount, and rate) and monitoring of resuscitative efforts. Available evidence for the impact of various fluids and resuscitative strategies on the microcirculation will also be reviewed.

• glycocalyx
• hemorrhage
• macrocirculation
• microcirculation
• sepsis
• shock

• Microcirculation
• Near-infrared
• Spectroscopy
• Spinal anesthesia

Dynamic parameters of preload have been widely recommended to guide fluid therapy based on the principle of fluid responsiveness and with regard to cardiac output. An equally important aspect is however to also avoid volume-overload. This accounts particularly when capillary leakage is present and volume-overload will promote impairment of microcirculatory blood flow. The aim of this study was to evaluate, whether an impairment of intestinal microcirculation caused by volume-load potentially can be predicted using pulse pressure variation in an experimental model of ischemia/reperfusion injury. The study was designed as a prospective explorative large animal pilot study. The study was performed in 8 anesthetized domestic pigs (German landrace). Ischemia/reperfusion was induced during aortic surgery. 6 h after ischemia/reperfusion-injury measurements were performed during 4 consecutive volume-loading-steps, each consisting of 6 ml kg⁻¹ bodyweight⁻¹. Mean microcirculatory blood flow (mean Flux) of the ileum was measured using direct laser-speckle-contrast-imaging. Receiver operating characteristic analysis was performed to determine the ability of pulse pressure variation to predict a decrease in microcirculation. A reduction of ≥ 10% mean Flux was considered a relevant decrease. After ischemia–reperfusion, volume-loading-steps led to a significant increase of cardiac output as well as mean arterial pressure, while pulse pressure variation and mean Flux were significantly reduced (Pairwise comparison ischemia/reperfusion-injury vs. volume loading step no. 4): cardiac output (l min⁻¹) 1.68 (1.02–2.35) versus 2.84 (2.15–3.53), p = 0.002, mean arterial pressure (mmHg) 29.89 (21.65–38.12) versus 52.34 (43.55–61.14), p < 0.001, pulse pressure variation (%) 24.84 (17.45–32.22) versus 9.59 (1.68–17.49), p = 0.004, mean Flux (p.u.) 414.95 (295.18–534.72) versus 327.21 (206.95–447.48), p = 0.006. Receiver operating characteristic analysis revealed an area under the curve of 0.88 (CI 95% 0.73–1.00; p value < 0.001) for pulse pressure variation for predicting a decrease of microcirculatory blood flow. The results of our study show that pulse pressure variation does have the potential to predict decreases of intestinal microcirculatory blood flow due to volume-load after ischemia/reperfusion-injury. This should encourage further translational research and might help to prevent microcirculatory impairment due to excessive fluid resuscitation and to guide fluid therapy in the future.

• conducted responses
• critical illness
• heterogeneity
• microvascular networks
• oxygen transport

Circulatory shock is associated with marked disturbances of the macro- and microcirculation and flow heterogeneities. Furthermore, a lack of tissue adenosine trisphosphate (ATP) and mitochondrial dysfunction are directly associated with organ failure and poor patient outcome. While it remains unclear if microcirculation-targeted resuscitation strategies can even abolish shock-induced flow heterogeneity, mitochondrial dysfunction and subsequently diminished ATP production could still lead to organ dysfunction and failure even if microcirculatory function is restored or maintained. Preserved mitochondrial function is clearly associated with better patient outcome. This review elucidates the role of the microcirculation and mitochondria during circulatory shock and patient management and will give a viewpoint on the advantages and disadvantages of tailoring resuscitation to microvascular or mitochondrial targets.

• circulatory shock
• hypoxia
• inflammation
• organ failure
• oxidative stress

• Microcirculation
• arginase
• atherosclerosis
• intensive care
• intravital microscopy
• nitric oxide

Microcirculatory perfusion disturbances are associated with increased morbidity and mortality in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Technological advancements made it possible to monitor sublingual microcirculatory perfusion over time. The goal of this review is to provide an overview of the course of alterations in sublingual microcirculatory perfusion following CPB. The secondary goal is to identify which parameter of sublingual microcirculatory perfusion is most profoundly affected by CPB.

PubMed and Embase databases were systematically searched according to PRISMA guidelines and as registered in PROSPERO. Studies that reported sublingual microcirculatory perfusion measurements before and after onset of CPB in adult patients undergoing cardiac surgery were included. The primary outcome was sublingual microcirculatory perfusion, represented by functional capillary density (FCD), perfused vessel density (PVD), total vessel density (TVD), proportion of perfused vessels (PPV), and microvascular flow index (MFI).

The search identified 277 studies, of which 19 fulfilled all eligibility criteria. Initiation of CPB had a profound effect on FCD, PVD, or PPV. Seventeen studies (89%) reported one or more of these parameters, and in 11 of those studies (65%), there was a significant decrease in these parameters during cardiac surgery; the other 6 studies (35%) reported no effect. In 29% of the studies, FCD, PVD, or PPV normalized by the end of cardiac surgery, and in 24% percent of the studies, this effect lasted at least 24 h. There was no clear effect of CPB on TVD and a mixed effect on MFI.

CPB during cardiac surgery impaired sublingual microcirculatory perfusion as reflected by reduced FCD, PVD, and PPV. Four studies reported this effect at least 24 h after surgery. Further research is warranted to conclude on the duration of CPB-induced microcirculatory perfusion disturbances and the relationship with clinical outcome.

PROSPERO, CRD42019127798

• Capillary perfusion
• Cardiac surgery
• Cardiopulmonary bypass
• Microcirculation
• Microcirculatory perfusion
• Sublingual

• Cardiogenic shock
• macrocirculatory perfusion
• microcirculatory perfusion
• myocardial infarction
• sublingual videomicroscopy

• Capillary refill time
• Circulatory shock
• Fluid responsiveness
• Microcirculation
• PCO2gap
• Passive leg raising
• Peripheral perfusion

• Aged
• Area Under Curve
• Capillaries/physiology
• Cardiac Output/physiology
• Female
• Hemodynamics/physiology
• Humans
• Male
• Middle Aged
• Plasma Substitutes/standards
• Plasma Substitutes/therapeutic use
• Prospective Studies
• ROC Curve
• Shock/blood
• Shock/physiopathology
• Time Factors