Cerebral Oxymeter and End Tidal Carbondioxide Values Under Surgical Drapes With and Without Past COVID-19 Infection

Today, phacoemulsification has become the most commonly applied method in the treatment of cataract, which is considered as a public health problem. Since the eyelid margins can be a source for pathogens in phacoemulsification surgery draping after skin sterilization is applied to remove the eyelashes from the operation area. Since surgical drapes are airtight, carbon dioxide (CO2) accumulation occurs under the drape in patients under local anesthesia. During the operation, if the end tidal CO2 pressure value rises, this can lead to hyperventilation and tachycardia and also increase the intraocular pressure which is undesirable in eye surgery. In our study, in order to observe and compare undesirable conditions, regional tissue oxygenation saturation (rSO2) will be determined non-invasively with Transcutaneous Near Infrared Spectroscopy (NIRS) technology , which allows real-time monitoring. Changes in the partial pressure of carbon dioxide (PaCO2) are strongly vaso-active, resulting in changes in cerebral blood volume and hence intracranial pressure. As the optic nerve sheath is an extension of the brain dura mater, the diameter of the sheath expands in case of increased intracranial pressure. Evaluation of the optic nerve sheath with ultrasound allows us to obtain information about intracranial pressure. For optic nerve sheath diameter, measurements above 5.0 mm in adult patients are generally considered as increased intracranial pressure. COVID-19 is a global epidemic caused by SARS-CoV-2 that we are still fighting. Although it is a multisystemic disease, it is important in terms of its effects on pulmonary function and the continuity of pulmonary symptoms and findings after this disease has been overcome. In our study, End-Tidal CO2 and cerebral oximetry (NIRS) values will be determined and compared between the groups that received 2lt/min and 4lt/min nasal oxygen support during cataract surgery performed using draping under local anesthesia in patients who ha