A Study Of The Effects Of Cyclooxygenase Inhibitor On Plateau Waves Of Intracranial Pressure In The Patients With STBI

Severe traumatic brain injury (sTBI) is a important issue, which has a very high mortality and morbidity, and has become a severe threaten to human health. Decreased cerebral perfusion and oxygenation in secondary injury are the main reason. Plateau waves are sudden and steep increases in intracranial pressure (ICP) that can develop in patients with cerebral injuries, reduced pressure - volume compensatory reserve, and preserved autoregulation. They are caused by cerebral vasodilation in response to a reduction in cerebral perfusion and are associated with increased cerebral blood volume. This years, the reseach using indomethacin to eliminate the plateau waves have been doing,but using indomethacin can bring hemorrhage of digestive tract. Under these conditions, the administration of lornoxicam, a new non-steroidal anti-inflammatory agent (NSAID), is a new way, which block the action of cyclo-oxygenase and the production of prostaglandins, acting as a potent cerebral arterial vasoconstrictor. It can improve the cerebral autoregulation, decrease cerebral blood volume and brain edema, eliminate the plateau waves , increase cerebral perfusion pressure and resume cerebral tissue PO₂.Object: To investigate the effects of cyclooxygenase inhibitor on plateau waves of intracranial pressure in the patients with sTBI. And research part of mechanism of lornoxicam's effect.Methods: 65 plateau waves developed in 34 patients,1- 3 episodes of plateau waves per patient were treated with lornoxicam (8 mg), which was delivered by an intravenous bolus injection. Each patient' s mean arterial blood flow (MABP), ICP, cerebral perfusion pressure (CPP), and cerebral tissue PO₂ were continuously monitored and the data obtained were stored in a personal computer. Each patient' s jugular venous O₂ saturation (SjvO₂) and venoarterial difference in PCO₂ were evaluated by intermittent blood sampling. During episodes of plateau waves, middle cerebral artery flow velocities were evaluated by transcranial Doppler ultrasonography. Compare the parameters before and after injection of lornoxicam during plateau waves.Results: Lornoxicam can extinguish the plateau waves. On average, the ICP decreased from an initial value of 59.9±10. 6 mm Hg to 21.1±8. 2 and 25. 4±12. 7 mm Hg after 5 and 10 minutes, respectively (p< 0. 01). The MABP did not change significantly. As a consequence the CPP increased from an initial value of 35. 8±9. 2 mm Hg to 74. 9±12. 6 and 67. 6±15. 0 mm Hg after 5 and 10 minutes, respectively (p< 0.01). Five and 10 minutes after indomethacin was administered, SjvO₂ increased from an initial value of 50. 5±10. 2% to 63.9±7.6% and 59. 8±9.4%, respectively (p<0.01).The cerebral tissue PO₂ increased from an initial value of 12.4±9.6 mm Hg to 23. 9±9. 3 and 22. 2±9. 1 mm Hg, respectively (p<0. 05), and the Pv - aCO₂ decreased significantly. The mean and diastolic flow velocities increased significantly, Vm increased from an initial value of 61.2±12. 1 cm/s to 75.9±15.0 and 77. 5±10. 3cm/s, respectively (p<0. 01), whereas the pulsatility index decreased from 1.38±0.56 to 1.08±0.40 (p < 0.05) at 5 minutes and 1.06±0.36 (p < 0.05) at 10 minutes.Conclusion: The findings confirm that plateau waves are caused by vasodilation and show that lornoxicam, by blocking the production of prostaglandins and constricting the cerebral arteries, is effective in extinguishing plateau waves, ultimately restoring cerebral perfusion and PbtO₂.