Effects of Acute Intracranial Hypertension on Extracerebral Organs: A Randomized Experimental Study in Pigs

Abstract

The study was conducted to determine the effects of isolated acute intracranial hypertension (AICH) on extracerebral organs. A total of 14 mechanically ventilated pigs were randomized to two groups of seven each: (1) control and (2) AICH. AICH was induced by inflating an intracranial balloon catheter. The inflation volume was adjusted to keep intracranial pressure between 30 and 40 cm H2O. Hemodynamics, gas-exchange, and global oxygen delivery parameters were observed over a 4-hour period. At the end of the 4-hour period, tissue samples of heart, lungs, liver, and kidneys were collected and histologically graded for inflammation, edema, and cell damage (necrosis) using semiquantitative scores. Animals with AICH had increased heart rate and cardiac output, and higher scores for inflammation, edema, and necrosis in heart, lung, kidney, and liver tissues (all p < 0.05). Peripheral and mixed-venous oxygen saturations were unaffected. Isolated AICH induces injury to multiple extracerebral organs, even in the absence of hypoperfusion or hypoxemia.