Diazepam in small doses may also be an option. Propofol in small 10mg increment doses can also be used especially prior to performing a local anaesthetic eye block. Some anaesthetists use small doses of alfentanil or fentanyl. The key to good sedation is to maintain verbal contact with the patient. Careful surgical draping is also important.
Patients become claustrophobic if their faces are draped.
Oxygen should be given to the patient, especially if sedation is to be used. Patients may find a face mask or nasal oxygen cannulae uncomfortable. Oxygen can be insufflated under the drapes using a breathing circuit. This also improves air circulation under the drapes. Many of the problems associated with local techniques can be avoided with a clear explanation of the procedure to the patient prior to commencing surgery, having a comfortable operating table, and somebody to hold the patient's hand throughout.