The Effect of Percutaneous Dilatational Tracheostomy on Intracranial Pressure

Since the study is a prospective observational study, the investigators will not be the decision-making physicians about the treatments applied to the patients. The optic nerve sheath diameter measurement method by ultrasonography will be used to determine intracranial pressure.Intracranial pressure measurement will be performed in neutral position before PDT, after the patient is positioned for the procedure, immediately after the procedure and immediately after the patient is placed in neutral position. Demographic characteristics, comorbidity status, PDT indication, intensive care unit hospitalisation diagnosis, intracranial pathology data, haemodynamic data, arterial blood gas parameters will be recorded.