Regional perfusion monitoring in shock

Abstract

Purpose of review Despite restoration of adequate systemic blood flow in patients with shock, single organs may remain hypoperfused. In this review, we summarize the results of a literature research on methods to monitor single organ perfusion in shock. We focused on methods to measure heart, brain, kidney, and/or visceral organ perfusion. Furthermore, only methods that can be used in real-time and at the bedside were included. Recent findings We identified studies on physical examination techniques, electrocardiography, echocardiography, contrast-enhanced ultrasound, near-infrared spectroscopy, and Doppler sonography to assess single organ perfusion. Summary Physical examination techniques have a reasonable negative predictive value to exclude single organ hypoperfusion but are nonspecific to detect it. Technical methods to indirectly measure myocardial perfusion include ECG and echocardiography. Contrast-enhanced ultrasound can quantify myocardial perfusion but has so far only been used to detect regional myocardial hypoperfusion. Near-infrared spectroscopy and transcranial Doppler sonography can be used to assess cerebral perfusion and determine autoregulation thresholds of the brain. Both Doppler and contrast-enhanced ultrasound techniques are novel methods to evaluate renal and visceral organ perfusion. A key limitation of most techniques is the inability to determine adequacy of organ blood flow to meet the organs’ metabolic demands.

Application Value of Emergency Bedside Echocardiography in Early Warning of Acute and Severe Shock and Clinical Classification

“…Bedside ultrasound can measure and calculate the IVCmax, IVCmin, and SCI of patients, judge the blood volume of patients, so as to early judge the state of shock, and guide emergency fluid resuscitation treatment [ 16 ]. As the vein with the largest blood flow in the human body, the inferior vena cava has a good correlation with the CVP, so it can be adopted to evaluate the blood volume of the body during shock [ 17 ]. The trunk of inferior vena cava is longer compared to superior vena cava and can be easily measured by ultrasound [ 18 ].…”

Intrarenal Doppler approaches in hemodynamics: A major application in critical care

“…The resultant poor perfusion may persist for long even when systemic hemodynamics is reversed ( Suarez and Busse, 2020 ). The final step of shock resuscitation aims to optimize single organ perfusion following the reversal of systemic hypoperfusion and restoration of microcirculatory perfusion ( Noitz et al, 2020 ). Therefore, assessing renal perfusion is critical and should take precedence over the perfusion assessment of other organs.…”