Perioperative goal-directed hemodynamic therapy aims at optimizing global hemodynamics during the perioperative period by titrating fluids, vasopressors, and/or inotropes to reach predefined hemodynamic goals. Current evidence indicates that treating patients according to perioperative goal-directed hemodynamic therapy protocols reduces morbidity and mortality, particularly in patients having high-risk surgery. However, its adoption into clinical practice is still weak.

This strategy has also improved greatly over the past 40 years. Monitoring technology has evolved to enable very invasive devices to be replaced by much less invasive (and even totally non-invasive) equipment. Simultaneously, our whole approach to monitoring has shifted from using a few static, single measures to a functional, dynamic, and multivariable approach. Finally, we are moving from standard, protocolized hemodynamic strategies to a more personalized approach to ensure appropriate management of each patient. For this purpose, closed-loop systems are an appealing added value to ensure that therapies are delivered appropriately to all patients.

Restoring the microcirculation and tissue oxygenation is the ultimate goal of hemodynamic resuscitation. Hand-held vital microscopes enable direct visualization of the sublingual microcirculation of RBC flow through the capillaries and the density of perfused capillaries. The association between alterations of sublingual microvascular parameters and patient outcomes during shock validates that these parameters are clinically relevant for the assessment of patients in shock. Assessment of sublingual microvascular perfusion parameters at the bedside is only conceivable if hand-held vital microscopes are easy to use and if the analysis of the images can be done in real time. Studies have shown that real-time point-of-care assessment by visual inspection of microcirculatory properties at the bedside shows good agreement with off-line evaluation of the microcirculation. The development of automatic microcirculatory analysis software systems will be the next step to obtain high-performance quantitative analysis at the patient’s bedside and for caregivers to adhere to this monitoring technique. Lastly, the impact of sublingual microcirculation on patient outcome remains to be proven during the perioperative setting.

In the USA, injury is the leading cause of death among individuals between the ages of 1 and 44 years, and the third leading cause of death overall. Approximately 20 to 40% of trauma deaths occurring after hospital admission are related to massive hemorrhage and are potentially preventable with rapid hemorrhage control and improved resuscitation techniques. Over the past decade, the treatment of this population has transitioned into a damage control strategy with the development of resuscitation strategies that emphasize permissive hypotension, limited crystalloid administration, early balanced blood product transfusion, and rapid hemorrhage control. This resuscitation approach initially attempts to replicate whole blood transfusion, utilizing an empiric 1:1:1 ratio of plasma:platelets:red blood cells, and then transitions, when bleeding slows, to a goal-directed approach to reverse coagulopathy based on viscoelastic assays. Traditional resuscitation strategies with crystalloid fluids are appropriate for the minimally injured patient who presents without shock or ongoing bleeding. This chapter focuses on the assessment and resuscitation of seriously injured trauma patients who present with ongoing blood loss and hemorrhagic shock.

Clinical decision support and closed-loop systems are ubiquitous to any modern lifestsyle. From maintaining ambient temperature to flying our airplanes, we have accepted and benefited from these tools. In this chapter, we discuss key concepts in design and clinical goals, as well as the challenges, of these systems in the context of perioperative medicine. We particularly focus on the past and present development of automated and decision support systems for hemodynamic optimization with fluids and vasopressors.