a comparison of cerebral and venous microdialysis during experimental hypothermic antegrad cerebral...
TRANSCRIPT
A comparison of cerebral and venous microdialysis during experimental hypothermic antegrad cerebral perfusion.
Authors:Jonsson O, Tovedal T, Zemgulis V, Lennmyr F, Hillered L,
Thelin S.
Department of Cardiothoracic surgery and anesthesiologyDepartment of Neuroscience, Neurosurgery
Uppsala University Uppsala University Hospital, Sweden
SACP Selective Antegrade Cerebral Perfusion
A Carotis communis
Aortic cannula
Clamps
Microdialysis
Lactate/pyruvate
Lactate/glucose
Background
• To encircle any signs of energy metabolic crisis and cellular distress during SACP flows between 6 ml/kg/min and 4 ml/kg/min.
• Can intravenous microdialysis in the sagittal sinus reveal global cerebral metabolic changes not detected by the brain microdialysis catheter.
Aims
• To investigate the effects of two SACP flow levels (6 and 4 ml/kg/min) on the development of cerebral ischemia.
• To evaluate the agreement and correlation between microdialysis markers harvested from the brain and the sagittal sinus.
Method
• Randomized study• 3 groups• 18 pigs (0 excluded)• Microdialysis (Cerebral, Sinus sagittal)• NIRS (Near infrared spectroscopy)• Cooling temperature 20oC
Experimental protocol
Group 1(○) SACP 4 ml/kg/min increased to 6 ml/kg/min/
Group 2 (∆) SACP 6 ml/kg/min decreased to 4 ml/kg/min
Group 3 (●) Control
0 30 60 90 120 150 1800
50
100
150
CPBCooling SACP SACP
S vO 2A
Time (min)
%
0 30 60 90 120 150 18060
80
100
120
140
CPBCooling SACP SACP
TOI relative
* *
B
Time (min)
%
0 30 60 90 120 150 1800
20
40
60
80
100
CPBCooling SACP SACP
MAPC
Time (min)
mm
Hg
0 30 60 90 120 150 1800
5
10
15
CPBCooling SACP SACP
Blood lactate
* *
D
Time(min)
µmol
/l
ResultsNIRS tissue oxygen index (TOI)
ResultsMicrodialysis from the brain
0 30 60 90 120 150 1800
2
4
6
A. Glucose CNSCPB
Cooling SACP SACP
Time (min)
mm
ol/l
0 30 60 90 120 150 1800
2
4
6
8
CPBCooling
SACP SACP
B. Lactate CNS
*
Time (min)
mm
ol/l
0 30 60 90 120 150 1800
100
200
300
CPBCooling SACP SACP
C. Pyruvate CNS
*
Time (min)
µmol
/l
0 30 60 90 120 150 1800
20
40
60
80
CPBCooling SACP SACP
D. L/P ratio CNS
*
Time (min)
0 30 60 90 120 150 1800
50
100
150
E. Glutamate CNSCPB
Cooling SACP SACP
Time (min)
µmol
/l
0 30 60 90 120 150 1800
50
100
150
200
250
CPBCooling SACP SACP
F. Glycerol CNS
Time (min)
µmol
/l
Results Microdialysis from the sagittal sinus
0 30 60 90 120 150 1800
5
10
15
A. Glucose SSCPB
Cooling SACP SACP
Time (min)
mm
ol/l
0 30 60 90 120 150 1800
2
4
6
8
10
12
CPBCooling SACP SACP
B. Lactate SS
Time (min)
mm
ol/l
0 30 60 90 120 150 1800
100
200
300
CPBCooling SACP SACP
C. Pyruvate SS
Time (min)
µmol
/l
0 30 60 90 120 150 1800
20
40
60
80
100
120
CPBCooling SACP SACP
D. L/P ratio SS
Time (min)
0 30 60 90 120 150 1800
50
100
150
200
250
CPBCooling SACP SACP
E. Glutamate SS
Time (min)
µmol
/l
0 30 60 90 120 150 1800
200
400
600
800
CPBCooling SACP SACP
F. Glycerole SS
*
*
Time (min)
µmol
/l
Probably the effect of circulatory arrest
Results Bland Altman
Results Correlation and Agreement
Table 3. Spearman’s correlation, bias, and limits of agreement between cerebral and sagittal sinus MD samples (n=119).
Comparison Correlation (r) Bias Limits of agreement p value
Glucose 0.41 - 3.8 - 9.2 to + 1.6 <0.01
Lactate 0.25 - 2.1 - 6.6 to + 4.5 0.08
Pyruvate - 0.02 - 35.7 -179.4 to + 108.0 0.87
Urea 0.32 - 0.7 - 2.2 to + 0.8 0.02
L/P ratio - 0.02 - 5.8 -49.0 to + 37.4 0.88
L/G ratio 0.15 2.0 - 6.3 to + 10.4 0.30
Glutamate 0.11 - 49.0 -152.9 to + 54.9 0.45
Glycerol 0.03 80.9 -71.4 to + 233.3 0.85
Conclusion
• An SACP flow of 6 ml/kg/min preserves cerebral metabolism according to cerebral microdialysis and NIRS.
• An SACP flow of 4 ml/kg/min induces early signs of disturbed energy metabolism.
• Microdialysis from the sagittal sinus is a feasible methode for monitoring biomarkers of global cerebral perturbations,
• But in the present model correlation with parenchymal measurements were poor and no agreement could be demonstrated.