Pharmacological normalization of circulation after acute brain death.
BACKGROUND
Circulatory instability is a serious problem after brain death in organ donors. The hypotension is often counteracted with infusion of large amounts of crystalloid solutions, which may impair lung function leading to rejection of the lungs as donor organs. The aim was to show that the circulation can be normalized pharmacologically for 24 h in pigs after total removal of the brain and brainstem by decapitation (between C2 and C3).


METHODS
Twenty-four 40-kg pigs (n = 8 × 3) were included: non-decapitated, decapitated, and decapitated with pharmacological treatment. All animals got the same basal fluid supply and ventilation. The pharmacological treatment consisted of the neuronal monoamine reuptake blocker cocaine and low doses of noradrenaline and adrenaline. Desmopressin, triiodothyroxine, thyroxine and cortisol were also given.


RESULTS
After decapitation, a catecholamine storm occurred, with an increase of noradrenaline and adrenaline by a factor of 79 and 298, respectively. Thirty minutes later, the pigs were hypotensive. The median time to the aortic pressure that was less than 40 mmHg was 9:09 h (range 5:50 to 22:01). After 6 h, the concentration of thyroid hormones and cortisol was significantly reduced. With pharmacological treatment of decapitated animals, the aortic pressure, renal blood flow, creatinine, urine production, liver function and blood gases did not differ significantly from the non-decapitated control animals.


CONCLUSIONS
Pharmacological substitution of pituitary gland function, blockade of peripheral catecholamine neuronal reuptake and low doses of catecholamines normalize circulation in decapitated pigs throughout a 24-h observation period, whereas untreated decapitated pigs all develop severe circulatory collapse within 12 h.
Department of Cardiothoracic Surgery, Lund University Hospital and Lund University, Sweden. stig.steen@med.lu.se
S
S
Steen
T
T
Sjöberg
Q
Q
Liao
G
G
Bozovic
B
B
Wohlfart
D000758:Anesthesia; D000818:Animals; D062186:Arterial Pressure / Q000187:drug effects; D001775:Blood Circulation / Q000187:drug effects*; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001926:Brain Death / Q000503:physiopathology*; D001933:Brain Stem / Q000502:physiology; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D049248:Decapitation; D004837:Epinephrine / Q000097:blood / Q000494:pharmacology; D005440:Fluid Therapy; D020249:Hormone Replacement Therapy; D006854:Hydrocortisone / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000097:blood / Q000494:pharmacology; D012079:Renal Circulation / Q000187:drug effects; D013552:Swine; D013974:Thyroxine / Q000494:pharmacology; D014284:Triiodothyronine / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000097:blood / Q000494:pharmacology
D014662:Vasoconstrictor Agents; D014284:Triiodothyronine; D003894:Deamino Arginine Vasopressin; D013974:Thyroxine; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine