Anesthesia, Blood Pressure
Conditions
Keywords
Anesthesia, Blood pressure, Plasma Volume, Vasopressor agents, Coronary artery bypass, Glycocalyx, ANP, Coagulation
Brief summary
The arterial blood pressure is thought to affect the ratio between filtration and reabsorption of fluids in the circulating blood volume and thereby the plasma volume. During induction of anesthesia blood pressure, hemoglobin level and hematocrits decreases and the plasma volume increases. The aim of the study is to evaluate weather a maintained blood pressure with norepinephrine during anesthesia induction reduces the increase in 125 iodine-labeled human serum albumine (125I-HSA) measured plasma volume.
Detailed description
24 patients scheduled for coronary artery bypass surgery will be included and randomized to receive either norepinephrine in the dose needed to maintain pre-anesthesia blood pressure or to a control group and receive norepinephrine only if mean arterial pressure decreases below 60 mmHg. Equal anesthesia in both groups will be monitored. No fluids will be infused. Changes in vascular resistance and cardiac output will be measured with thermodilution and changes in plasma volume will be measured with 125I-HSA. Endothelial cell function will be evaluated by measuring leakage of 125I-HSA and the plasma concentration of endothelial cell markers. Hormonal effects will be evaluated by measuring the plasma concentration of atrial natriuretic peptide (ANP). Shedding of glycocalyx will be evaluated by measuring heparan sulphate. The level of fibrinogen and platelet function will be evaluated by thromboelastography/multiplate.
Interventions
DRUGNorepinephrine
Ordinary anaesthesia and maintained preanesthetic blood pressure by norepinephrine infusion
PROCEDUREMaintained blood pressure
Norepinephrine therapy to maintain preanesthesia blood pressure
Sponsors
Sahlgrenska University Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
40 Years to 90 Years
Healthy volunteers
No
Inclusion criteria
* Elective coronary artery surgery patients
Exclusion criteria
* Age under 40 years * Untreated hypertension * A reduced left ventricular systolic ejection fraction of 45% or less * Diabetes mellitus * Former stroke and/or a known carotid artery stenosis
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The change of plasma volume measured by 125I-HSA before anesthesia induction until 50 minutes after anesthesia induction. | 50 minutes from anesthesia induction | To assess if the increase in plasma volume measured by 125I-HSA can be reduced by maintaining the blood pressure with vasopressor infusion. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Difference in 125I-HSA leakage | 50 minutes from anesthesia induction | To assess if there is a difference in 125I-HSA leakage in between the control and intervention groups before and after anaesthesia induction |
| ANP, heparan sulphate, thrombomodulin, fibrinogen, ROTEM | 50 minutes from anesthesia induction | To assess if there is a difference in the plasma concentration of ANP, heparan sulphate, thrombomodulin, fibrinogen and ROTEM before and after anaesthesia induction in the intervention group compared to the control group |
Countries
Sweden
Outcome results
None listed