Determination and clinical significance of plasma levels of prostaglandins in patients with acute brain injury.

BACKGROUND: Models of brain injury in experimental animals have shown that the level of prostaglandins (PGs) is increased in damage brain tissue, and that PGs play an important role in secondary brain damage. Almost all previous studies of the relationship between PGs and brain injury have been carried out in animals. In the present study we show that the PGs change in humans with brain injury.

METHODS: The plasma levels of thromboxane B2, 6-Keto-PGF2alpha, prostaglandin F2alpha, and prostaglandin E2 were measured by radioimmunoassay on the 1st, 3rd, 7th, and 14th days after brain injury. The same measurements were made on a control group of 26 healthy volunteers.

RESULTS: The levels of all four PGs were elevated, most markedly in the first week, with levels remaining high in the second week in the severely injured. On the first day levels were, on average, three times those found in the controls, with a seven-fold rise in some of the severely injured patients. Dividing the patients into three groups according to outcome, it was found that if the PGs were markedly increased to begin with and remained high, death or permanent disability was likely. In the group with good outcome, the levels dropped steadily from the initial high levels. The T/K ratio was studied. It related closely to the severity of injury, being higher in more severe injuries and decreasing with recovery. In patients who did not recover, the ratio increased steadily to its highest value on the 7th day, and remained high at the 14th.

CONCLUSION: Changes in PGs levels were closely related to the brain injury severity and its outcome, and there was a marked disturbance of the levels of PGs, which therefore appears to be an important indicator of secondary brain damage.