ISSN:
1432-055X
Keywords:
Schlüsselwörter Hypovolämischer Schock
;
Hyperosmolare Lösungen
;
Dextran
;
Hydroxyäthylstärke
;
Small-volume Resuscitation
;
Mikrozirkulation
;
PMNL-Funktion
;
Endothel-Reperfusionsschaden
;
Bauchaortenaneurysma
;
PFC
;
Key words Hypovolemic shock
;
Hyperosmolar solutions
;
Dextran
;
Hydroxyethyl starch
;
Small-volume resuscitation
;
Microcirculation
;
PMNL function
;
Endothelium
;
Reperfusion injury
;
Abdominal aortic aneurysm
;
PFC
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Description / Table of Contents:
Abstract The concept of small-volume resuscitation, the rapid infusion of a small volume (4 ml/kg BW) of hyperosmolar 7.2–7.5% saline solution for the initial therapy of severe hypovolemia and shock was advocated more than a decade ago. Numerous publications have established that hyperosmolar saline solution can restore arterial blood pressure, cardiac index and oxygen delivery as well as organ perfusion to pre-shock values. Most prehospital studies failed to yield conclusive results with respect to a reduction in overall mortality. A meta-analysis of preclinical studies from North and South America, however, has indicated an increase in survival rate by 5.1% following small-volume resuscitation when compared to standard of care. Moreover, small-volume resuscitation appears to be of specific impact in patients suffering from head injuries with increased ICP and in severest trauma requiring immediate surgical intervention. Results from clinical trials in Austria, Germany and France have demonstrated positive effects of hyperosmolar saline solutions when used for fluid loading or fluid substitution in cardiac bypass and in aortic aneurysm surgery, respectively. A less positive perioperative fluid balance, a better hemodynamic stability and improved pulmonary function were reported. In septic patients oxygen consumption could significantly be augmented. The most important mechanism of action of small-volume resuscitation is the mobilisation of endogenous fluid primarily from oedematous endothelial cells, by which the rectification of shock-narrowed capillaries and the restoration of nutritional blood, flow is efficiently promoted. Moreover after ischemia reperfusion a reduction in sticking and rolling leukocytes have been found following hyperosmolar saline infusion. Both may be of paramount importance in the long-term preservation of organ function following hypovolemic shock. An increased myocardial contractility in addition to the fluid loading effects of hyperosmolar saline solution has been suggested as a mechanism of action. This, however, could not be confirmed by pre-load independent measures of myocardial contractility. Some concerns have been raised regarding the use of hyperosmolar saline solutions in patients with a reduced cardiac reserve. A slower speed of infusion and adequate monitoring is recommended for high risk patients. Recently, hyperosmolar saline solutions in combination with artificial oxygen carriers have been proposed to increase tissue oxygen delivery through enhanced O2 content. This interesting perspective, however, requires further studies to confirm the potential indications for such solutions. Many hyperosmolar saline colloid solutions have been investigated in the past years, from which a 7.2–7.5% sodium chloride in combination with either 6–10% dextran 60/70 or 6–10% hydroxyethyl starch 200,000 appear to yield the best benefit-risk ratio. This has led to the registration of the solutions in South America, Austria, the Czech Republic, and is soon awaited for North America.
Notes:
Zusammenfassung Die Bolusinfusion einer hyperosmolaren Kochsalzlösung (4 ml/kg, 7,2–7,5% NaCl) führt im hypovolämischen Schock zur raschen Normalisierung der zentralen Hämodynamik und zur Restitution der Organperfusion (Small-volume Resuscitation). Nach Ischämie ist die Wiederherstellung der Perfusion in der mikrovaskulären Strombahn vorrangig. Hyperosmolare Lösungen verbessern die Mikrozirkulation durch Reduktion der Endothelzellschwellung und Verminderung der Leukozytenadhäsion am Endothel. Die Wirkmechanismen und die Effizienz hyperosmolarer Lösungen sind durch experimentelle Untersuchungen gut belegt. Hingegen konnte bislang keine der präklinischen Studien die Überlegenheit hyperosmolarer Lösungen hinsichtlich der Überlebensrate sichern! Eine Metaanalyse der bei Traumapatienten vorliegenden Ergebnisse (n = 1.889) zeigte eine Reduktion der Letalität bei den mit hyperosmolarer Lösung behandelten Traumapatienten. Vielversprechende neue Indikationsgebiete für hyperosmolare Kochsalzlösungen stellen der Einsatz in der Kardio- und Gefäßchirurgie, bei Brandverletzten, bei Patienten mit Sepsis sowie die gezielte Therapie des postischämischen Reperfusionsschadens dar. Die Kombination hyperosmolarer Lösungen mit künstlichen Sauerstoffträgern ist zur Zeit in experimenteller Erprobung.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s001010050406
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