Klaus Lucke, Silvia Bopp, Hermann Eilers Bremen, Germany

Anesthesia constitutes a special challenge in vitreoretinal surgery since a disproportionate number of our patients are old and in bad general health. In our series 40% of patients are 70 years or older, 62% are hypertonic, 37% have coronary heart disease, 35% cardiac insufficiency and 35% obstructive or restrictive lung disease. 23% have diabetes mellitus and about 33% are classified as ASA III and a few even as ASA IV.
There is a widespread tendency to consider local anesthesia “safer” in these high-challenge cases, although it is known that more than 50% of patients exhibit hypertonic dysregulation and 15% develop bradycardia and arrhythmia during such operations. We found that 80% of our patients developed a raised pCO2 during vitreoretinal procedures, which are known to take much longer than cataract operations. A number of these patients can become disoriented as a result of this.
Fortunately as much as vitreoretinal surgery has undergone profound change in the last 10-15 years general anesthesia in recent times has been revolutionized by newer drugs and more sophisticated methods of monitoring. As a result general anesthesia has become much safer and there are far fewer side effects than with more traditional methods. By modern standards general anesthesia is at least as safe as local anesthesia. Propofol for hypnosis, Remifentanyl as an analgesic and substances such as Vecuronium or Mivacuronium for short term relaxation are used in combination and titrated in close response to the requirements of the actual stage of the surgical procedure. Sedation is not used at all anymore. The peripheral pO2, blood pressure, ECG, pulse and frequently pCO2 are monitored throughout and can be adjusted actively by the anesthesiologist. This allows for a rapid recovery postoperatively, most patients being able to take in oral fluids and food within 20-30 minutes of the end of the procedure and discharged from the clinic within 2 hours. The safety of this method is witnessed by the fact that there has only been one very serious adverse event in 7 years, and that was in a patient with ASA IV.
After 7000 vitreoretinal operations, 97% of which in general anesthesia, we consider this to be our method of choice. It provides for a quiet patient allowing us to concentrate fully on the task. Risks to the eye by the retrobulbar or parabulbar injection are eliminated and there is no problem if the operation takes longer. The few minutes we lose through intubation are easily gained by the more efficient surgery. Since recovery is rapid we can even perform macular rotation surgery routinely on an outpatient basis.