Open randomized trial of the effects of 6% hydroxyethyl starch 130/0.4/9 and 5% albumin on safety profile, volume efficacy, and glycocalyx degradation in hepatic and pancreatic surgery

Comparison of six percent hydroxyethyl starch 130/0.4 and ringer's lactate as priming solutions in patients undergoing isolated open heart valve surgery: A double-blind randomized controlled trial

OBJECTIVES

Colloids are added to the priming solution of the cardiopulmonary bypass (CPB) pump to maintain colloid osmotic pressure and prevent fluid overload. This study aimed to compare the effects of 6% hydroxyethyl starch (HES) 130/0.4 and ringer's lactate (RL) priming solution on patients' outcomes undergoing isolated heart valve surgery with CPB.

METHODS

This randomized clinical trial included one hundred and 20 patients undergoing heart valve surgery, and those were allocated into two groups. Patients in the RL group received 1500 mL of RL, and those in the RL + HES group were given 500 mL of HES and 1000 mL of RL.

RESULTS

The patients' median age was 52 (IQR 42-60) and 50 (IQR 40-61) years in the RL + HES and the RL group, respectively (p = .71). The number of cases that required blood product transfusion in both the operating room and intensive care unit was also significantly higher in the RL + HES group compared to the RL group (RR 2.04, 95% CI 1.50-2.76; p < .01 and RR 1.42, 95% CI 1.01-2.01; p = .05, respectively). Declines in postoperative creatinine levels and platelet counts were higher in the RL + HES compared to the RL group (between-subjects effect p = .007 and p = .038, respectively), while the incidence of acute kidney injury was comparable between groups (RR 0.66, 95% CI 0.13-3.30; p = .55).

CONCLUSIONS

Among patients undergoing heart valve surgery with CPB, 6% HES added to RL for priming compared with only RL increased the risk of the need for blood product transfusion over the hospitalization period.

Microcirculation and Mitochondria: The Critical Unit

Critical illness is often accompanied by a hemodynamic imbalance between macrocirculation and microcirculation, as well as mitochondrial dysfunction. Microcirculatory disorders lead to abnormalities in the supply of oxygen to tissue cells, while mitochondrial dysfunction leads to abnormal energy metabolism and impaired tissue oxygen utilization, making these conditions important pathogenic factors of critical illness. At the same time, there is a close relationship between the microcirculation and mitochondria. We introduce here the concept of a "critical unit", with two core components: microcirculation, which mainly comprises the microvascular network and endothelial cells, especially the endothelial glycocalyx; and mitochondria, which are mainly involved in energy metabolism but perform other non-negligible functions. This review also introduces several techniques and devices that can be utilized for the real-time synchronous monitoring of the microcirculation and mitochondria, and thus critical unit monitoring. Finally, we put forward the concepts and strategies of critical unit-guided treatment.

Perioperative fluid management for lung transplantation is challenging

Lung transplantation is the definitive end-stage treatment for many lung diseases, and postoperative pulmonary oedema severely affects survival after lung transplantation. Optimizing perioperative fluid management can reduce the incidence of postoperative pulmonary oedema and improve the prognosis of lung transplant patients by removing the influence of patient, donor's lung and ECMO factors. Therefore, this article reviews seven aspects of lung transplant patients' pathophysiological characteristics, physiological characteristics of fluids, the influence of the donor lung on pulmonary oedema as well as current fluid rehydration concepts, advantages or disadvantages of intraoperative monitoring tools or types of fluids on postoperative pulmonary oedema, while showing the existing challenges in section 7. The aim is to show the specificity of perioperative fluid management in lung transplant patients and to provide new ideas for individualised fluid management in lung transplantation.

Resuscitation fluids as drugs: targeting the endothelial glycocalyx

ABSTRACT

Fluid resuscitation is an essential intervention in critically ill patients, and its ultimate goal is to restore tissue perfusion. Critical illnesses are often accompanied by glycocalyx degradation caused by inflammatory reactions, hypoperfusion, shock, and so forth, leading to disturbed microcirculatory perfusion and organ dysfunction. Therefore, maintaining or even restoring the glycocalyx integrity may be of high priority in the therapeutic strategy. Like drugs, however, different resuscitation fluids may have beneficial or harmful effects on the integrity of the glycocalyx. The purpose of this article is to review the effects of different resuscitation fluids on the glycocalyx. Many animal studies have shown that normal saline might be associated with glycocalyx degradation, but clinical studies have not confirmed this finding. Hydroxyethyl starch (HES), rather than other synthetic colloids, may restore the glycocalyx. However, the use of HES also leads to serious adverse events such as acute kidney injury and bleeding tendencies. Some studies have suggested that albumin may restore the glycocalyx, whereas others have suggested that balanced crystalloids might aggravate glycocalyx degradation. Notably, most studies did not correct the effects of the infusion rate or fluid volume; therefore, the results of using balanced crystalloids remain unclear. Moreover, mainly animal studies have suggested that plasma may protect and restore glycocalyx integrity, and this still requires confirmation by high-quality clinical studies.

[Solutions for Fluid Treatment and Outcome - an Update]

Fluid therapy is one of the most frequently used medical interventions with the aim of normalizing the fluid balance. A decisive criterion for the efficiency of fluid or volume replacement is the functionality of the glycocalyx, a thin endothelial glycoprotein layer. Its solidity is an essential factor for fluid exchange and transport from the vascular system to the tissue. The recently described revised Starling principle extends the understanding considerably. From a clinical point of view, fluid treatment should aim for timely euvolemia without inducing relevant side effects. Both crystalloid and natural or synthetic colloidal solutions are available. In the case of crystalloid solutions, the so-called balanced solutions seem to be associated with fewer side effects. If the vascular barrier is intact, colloid solutions have a higher volume effect, but may have significant side effects limiting their use. At least in Europe, some synthetic colloids shall therefore no longer be used in critically ill patients. In contrast, treatment with albumin 20% in hypalbuminemic patients with cardiovascular disease leads to a reduced incidence of acute kidney injury and has also been associated with other clinical benefits. To what extent future, individualized therapeutic approaches employing colloids will influence the outcome is currently speculative.