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Cardiac response is greater for colloid than saline fluid loading after cardiac or vascular surgery
Joanne Verheij1, Arthur van Lingen, Albertus Beishuizen
1Department of Intensive Care, VU Medical Centre, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
Insights
Colloid solutions effectively expand plasma volume and improve cardiac function compared to saline in patients with hypovolemic hypotension after surgery. This fluid resuscitation strategy enhances myocardial performance by increasing preload, unlike crystalloids.
Area of Science:
- Critical Care Medicine
- Cardiovascular Surgery
- Fluid Resuscitation
Background:
- Hypovolemic hypotension is a common complication after cardiac and major vascular surgery.
- Appropriate fluid resuscitation is crucial for hemodynamic stability and myocardial function.
- The choice between colloids and crystalloids for fluid therapy remains a subject of investigation.
Purpose of the Study:
- To compare the effects of colloids versus crystalloids on volume expansion and myocardial function in patients with hypovolemic hypotension.
- To evaluate the impact of different fluid types on hemodynamic parameters and cardiac performance post-surgery.
Main Methods:
- A single-center, single-blinded, randomized clinical trial involving 67 patients.
- Patients received a 90-minute fluid challenge guided by filling pressures using saline 0.9%, gelatin 4%, hydroxyethyl starch 6%, or albumin 5%.
- Hemodynamic variables and colloid osmotic pressure (COP) were measured using transpulmonary thermodilution.
Main Results:
- Colloid solutions resulted in greater plasma volume expansion (19% vs. 3.0% for saline) and a significant increase in cardiac index (22% vs. 13% for saline).
- Colloid fluid loading led to a greater increase in left ventricular stroke work index compared to saline.
- The observed improvements in cardiac function correlated with increases in plasma volume and global end-diastolic volume.
Conclusions:
- Fluid response after cardiac or major vascular surgery is influenced by the type of fluid administered.
- Colloid fluid loading provides superior plasma volume expansion and enhances cardiac performance more effectively than saline.
- The increased plasma colloid osmotic pressure (COP) with colloids contributes to greater preload augmentation and improved myocardial function.
Objective:
To study the effects on volume expansion and myocardial function of colloids or crystalloids in the treatment of hypovolaemic hypotension after cardiac and major vascular surgery.
Design And Setting:
A single-centre, single-blinded, randomized clinical trial at the intensive care unit of a university hospital.
Patients And Methods:
Patients (n=67) were subjected to a 90-min filling pressure-guided fluid challenge with saline 0.9% or the colloids gelatin 4%, hydroxyethyl starch 6% or albumin 5%. Biochemical variables and haemodynamics (transpulmonary thermodilution) were measured.
Results:
An amount of 1800 (1300-1800) ml of saline or 1600 (750-1800) ml of colloid solution (P< 0.005) was infused. Colloid osmotic pressure (COP) decreased in the saline group and increased in the colloid groups (P< 0.001). Plasma volume increased by 3.0% (-18 to 24) in the saline versus 19% (-11 to 50) in the colloid groups (P< 0.001). Cardiac index increased by median 13% (ns) in the saline group and by 22% in the colloid groups (P<0.005). The rise in left ventricular stroke work index was greater in the colloid than in the saline groups. The different colloids were equally effective. The rise in cardiac index related to the rise in plasma volume and global end-diastolic volume, confirming plasma volume and preload augmentation by the fluid loading.
Conclusion:
After cardiac or major vascular surgery, the pressure- and time-guided fluid response is dependent on the type of fluid used. Colloid fluid loading leads to a greater increase in preload-recruitable cardiac and left ventricular stroke work indices than that with saline, because of greater plasma volume expansion following an increase in plasma COP.
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