Ischemia as a possible effect of increased intra-abdominal pressure on central nervous system cytokines, lactate and perfusion pressures.
BACKGROUND
The aims of our study were to evaluate the impact of increased intra-abdominal pressure (IAP) on central nervous system (CNS) cytokines (Interleukin 6 and tumor necrosis factor), lactate and perfusion pressures, testing the hypothesis that intra-abdominal hypertension (IAH) may possibly lead to CNS ischemia.


METHODS
Fifteen pigs were studied. Helium pneumoperitoneum was established and IAP was increased initially at 20 mmHg and subsequently at 45 mmHg, which was finally followed by abdominal desufflation. Interleukin 6 (IL-6), tumor necrosis factor alpha (TNFa) and lactate were measured in the cerebrospinal fluid (CSF) and intracranial (ICP), intraspinal (ISP), cerebral perfusion (CPP) and spinal perfusion (SPP) pressures recorded.


RESULTS
Increased IAP (20 mmHg) was followed by a statistically significant increase in IL-6 (p = 0.028), lactate (p = 0.017), ICP (p < 0.001) and ISP (p = 0.001) and a significant decrease in CPP (p = 0.013) and SPP (p = 0.002). However, further increase of IAP (45 mmHg) was accompanied by an increase in mean arterial pressure due to compensatory tachycardia, followed by an increase in CPP and SPP and a decrease of cytokines and lactate.


CONCLUSIONS
IAH resulted in a decrease of CPP and SPP lower than 60 mmHg and an increase of all ischemic mediators, indicating CNS ischemia; on the other hand, restoration of perfusion pressures above this threshold decreased all ischemic indicators, irrespective of the level of IAH.
Marinis
Athanasios
A
Second Department of Surgery, Aretaieion University Hospital, 76 Vassilisis Sofia's Av, Athens, Greece. drmarinis@gmail.com
Argyra
Eriphili
E
Lykoudis
Pavlos
P
Brestas
Paraskevas
P
Theodoraki
Kassiani
K
Polymeneas
Georgios
G
Boviatsis
Efstathios
E
Voros
Dionysios
D
D000005:Abdomen / Q000098:blood supply*; D000818:Animals; D002545:Brain Ischemia / Q000209:etiology*; D002490:Central Nervous System / Q000098:blood supply*; D003161:Compartment Syndromes; D016207:Cytokines / Q000134:cerebrospinal fluid*; D006973:Hypertension; D007511:Ischemia / Q000209:etiology; D007773:Lactates / Q000134:cerebrospinal fluid*; D008991:Monitoring, Physiologic; D010477:Perfusion; D011312:Pressure / Q000009:adverse effects*; D013131:Spine / Q000098:blood supply; D013552:Swine
D016207:Cytokines; D007773:Lactates