Effects of thoracic epidural anaesthesia on intestinal microvascular perfusion in a rodent model of normotensive endotoxaemia.
OBJECTIVE
To investigate whether sympathetic blockade by means of thoracic epidural anaesthesia (TEA) increases intestinal perfusion during normotensive endotoxaemia.


METHODS
A prospective, randomised and controlled animal study.


METHODS
Animal laboratory in a university hospital.


METHODS
Sprague-Dawley male rats.


METHODS
The rats were anaesthetised with urethane and ketamine, mechanically ventilated and haemodynamically monitored. Lidocaine or saline were infused continuously via thoracic epidural catheters followed by a continuous intravenous infusion of Escherichia coli lipopolysaccharide (1.5 mg/kg per h). Densities of perfused and non-perfused capillaries (i.e., with and without erythrocyte perfusion, respectively) as well as erythrocyte velocity in both the mucosa and the muscularis of the terminal ileum were determined using intravital microscopy.


RESULTS
Measurements were performed at baseline, after 30 min of epidural infusion as well as after 60 and 120 min of lipopolysaccharide infusion. In animals receiving TEA, mean arterial pressure and heart rate were significantly reduced throughout the experiment. In the muscularis the endotoxaemia-induced increase in non-perfused capillaries was absent with epidural lidocaine (0 [0/0] versus 39 [36/137] cm(-1), median [25(th)/75(th) percentile]), whereas in the mucosa perfused capillary density declined to a greater extent than in controls (-47 [-53/-23]%) versus -19 [-34/+10]%, p<0.05). Erythrocyte velocity decreased with endotoxaemia and was not influenced by epidural lidocaine.


CONCLUSIONS
Microvascular perfusion data during endotoxaemia show a redistribution of blood flow towards the mucosa. TEA seems to impede this redistribution resulting in improved muscularis and worsened mucosal microvascular perfusion.
Adolphs
Jörn
J
Department of Anaesthesiology and Critical Care Medicine, Campus Benjamin Franklin, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12200 Berlin, Germany. joern.adolphs@charite.de
Schmidt
Diego K
DK
Korsukewitz
Ines
I
Kamin
Britta
B
Habazettl
Helmut
H
Schäfer
Michael
M
Welte
Martin
M
D000767:Anesthesia, Epidural; D000818:Animals; D001340:Autonomic Nerve Block; D007413:Intestinal Mucosa / Q000098:blood supply* / Q000187:drug effects; D007422:Intestines / Q000098:blood supply* / Q000187:drug effects; D008070:Lipopolysaccharides; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D011446:Prospective Studies; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000187:drug effects; D018805:Sepsis / Q000503:physiopathology; D018709:Statistics, Nonparametric; D013904:Thoracic Vertebrae
D008070:Lipopolysaccharides