INTRAVENOUS ANESTHESIA WITH PROPOFOL AND KETAMINE FOR RETROBULBAR BLOCK IN OPHTHALMIC SURGERY

Background: Eye surgery is performed under local anesthesia in more th an 90% of the cases. While injecting the local anesthetics a deep seda tion is desired. During surgery however the patient should be cooperat ive, such as to avoid inadvertent movements. We routinely perform loca l anesthesia (retrobulbar injection and van Lint block) under intraven ous anesthesia with propofol (Disoprivan(R)) and ketamine (Ketalar(R), Ketanest(R)). Patients and methods: To control safety and efficacy of this method a prospective study was performed including 100 consecuti ve patients. The results were to be compared with an earlier study whe re 35 Patients received midazolam (Dormicum(R)) and alfentanil (Rapife n(R)) as sedation. The actual protocol included the following points: 1. Personel judgement of the patient, 2. Conditions to perform the ret robulbar injection, 3. Intraoperative conditions and additional sedati on, 4. Pulse, blood pressure and blood oxygen concentration, 5. Compli cations Results: >95% of the patients had a total amnesia of the injec tion of local anesthetics. Retrobulbar injection is comfortable (96%), but may be difficult in patients with a narrow orbit and exotropia (4 %). Intraoperative conditions were noted as good in 97%. Additional se dation during surgery was necessary in 3%. Blood pressure and pulse re mained stable. Blood oxygen concentration showed a tendency to sink du ring intravenous anesthesia. This could be managed easily by additiona l oxygen via face mask if necessary. Postoperative emesis was noted in 3%. No further ocular complications occured that might be related to the anesthetic management. In an earlier study including 35 Patients u nder comparable conditions we used midazolam and alfentanil for sedati on. The results were similar. Midazolam and alfentanil were then used in over 2000 operations. Often the patients were deeply sedated and as leep during surgery which meant a potential risk of a sudden awakening and moving the head inadvertently. Occasionally paradoxical reactions occurred after midazolam. Conclusions: Using propofol and ketamine wh ile performing the local anesthesia the patients are awake but relaxed and cooperative during surgery. This method has now been used routine ly in over 1000 cases. It has proved to be clinically safe and efficia nt. It offers the surgeon good working conditions and is well tolerate d by the patients, reducing their preoperative and perioperative anxie ties.