[Fluid resuscitation in hemorrhage]

How fluid resuscitation has to be performed for acute hemorrhage situations is still controversially discussed. Although the forced administration of crystalloids and colloids has been and still is practiced, nowadays there are good arguments that a cautious infusion of crystalloids may be initially sufficient. Saline should no longer be used for fluid resuscitation. The main argument for cautious fluid resuscitation is that no large prospective randomized clinical trials exist which have provided evidence of improved survival when fluid resuscitation is applied in an aggressive manner. The explanation that no positive effect has so far been observed is that fluid resuscitation is thought to boost bleeding by increasing blood pressure and dilutional coagulopathy. Nevertheless, national and international guidelines recommend that fluid resuscitation should be applied at the latest when hemorrhage causes hemodynamic instability. Consideration should be given to the fact that damage control resuscitation per se will neither improve already reduced tissue perfusion nor hemostasis. In acute and possibly rapidly progressing hypovolemic shock, colloids can be used. The third and fourth generations of hydroxyethyl starch (HES) are safe and effective if used correctly and within prescribed limits. If fluid resuscitation is applied with ongoing re-evaluation of the parameters which determine oxygen supply, it should be possible to keep fluid resuscitation restricted without causing undesirable side effects and also to administer a sufficient quantity so that survival of patients is ensured.

Effect of the colloids gelatin and HES 130/0.4 on blood coagulation in cardiac surgery patients: a randomized controlled trial

Objective:

The choice of the prime solution for cardiopulmonary bypass can play an important role in limiting the effect on blood coagulation, but it is still unclear what the effect of colloids on blood coagulation is. The aim of this study was to investigate the effect of synthetic colloids on blood loss and blood coagulation in patients after on-pump coronary artery bypass graft (CABG) procedures.

Methods:

Sixty elective, on-pump CABG patients were randomly assigned to receive the prime solutions lactated Ringer’s solution combined with hydroxyethyl starch 130/0.4 (HES, 6% Volulyte, Fresenius Kabi Nederland BV, Zeist, the Netherlands) (HES group) or gelatin (Gelofusin®, B Braun Melsung AG, Melsungen, Germany) (Gelo group). Blood loss was assessed using post-operative chest tube output; secondary endpoints were number of blood component transfusions, routine coagulation test values and rotation thromboelastometry values (Rotem® delta, Pentapharm GmbH, Munich, Germany).

Results:

Total post-operative chest tube output was 500 ± 420 ml in the HES group versus 465 ± 390 ml in the Gelo group ( p = 0.48). No significant differences were observed in any of the routine coagulation tests values, thromboelastometry parameters or number of blood component transfusions between the groups.

Conclusions:

In this randomized, controlled trial of adults after on-pump CABG procedures, there was no significant difference in blood loss or blood coagulation between the HES group and the Gelo group.

Coagulopathy and hemostatic monitoring in cardiac surgery: an update

OBJECTIVES

Cardiac surgery with cardiopulmonary bypass (CPB) causes severe derangements in the hemostatic system, which in turn puts the patient at risks of microvascular bleeding. Excessive transfusion and surgical re-exploration after cardiac surgery are potentially associated with a number of adverse outcomes including increased mortality.

DESIGN

This review describes coagulopathies occurring in cardiac surgery and the monitoring of these. Viscoelastic hemostatic assays (VHA) have routinely been used in cardiac surgery for more than 25 years and at least 16 studies (involving more than 3250 patients, including three randomized controlled trials) have compared VHA to routine coagulation tests (RCoT) with regards to their ability to predict bleeding and re-do surgery and also with regards to transfusion requirements secondary to hemostatic therapy based on VHA vs. RCoT.

RESULTS

All 16 studies demonstrated superiority with VHA as compared to RCoT both in predicting bleeding and need for re-do surgery and in reducing the total amount of blood transfusions by employing goal-directed administration of blood products based on VHA as compared RCoT based therapy or at the clinicians discretion.

CONCLUSIONS

The different types of coagulopathies observed in patients undergoing cardiac surgery requires adequate and timely hemostatic therapy and real-time monitoring with WHA such as TEG/ROTEM and whole blood platelet aggregometry.