[Propofol, isoflurane and neuroleptanesthesia. Ophthalmic surgery in geriatric patients]

Ophthalmic surgeons require anaesthesia to ensure that the patient is completely relaxed for microsurgical operations and that the intraocular pressure is reduced. These conditions must be maintained throughout the operation. In addition to these requirements, the anaesthetist mostly deals with elderly patients with multiple diseases. Although earlier studies have shown which general or local anaesthesia is preferred for which patients and operations, studies on which general anaesthesia technique is ideal to fulfil these requirements are still lacking. The aim of this study was to show which technique causes the least stress for a geriatric patient undergoing an ophthalmic operation, propofol/fentanyl anaesthesia, isoflurane anaesthesia or neuroleptanaesthesia. PATIENTS AND METHODS. Sixty patients aged 60 years and above were included in this study. After being randomly allocated to either propofol/fentanyl (continuous propofol infusion), isoflurane or neuroleptanaesthesia, they underwent ophthalmic surgery. Intraoperative complications (cardiocirculatory changes) and surgical conditions were recorded. After the operation, patient vigilance and post-operative pain reactions (nominal pain score) were assessed over 8 h by means of simple reaction tests and the Juhl index. Within the first 2 h after surgery, cardiocirculatory changes were also documented and arterial blood gases measured. RESULTS. The treatment groups did not differ with respect to general biometric data, preoperative risk or operations carried out. Intraoperative cardiocirculatory changes and the resulting therapy (positive inotropic drugs, volume replacement fluids) were similar in all groups. The surgical conditions were equally good in all groups. Apart from a lower rate pressure product in the first 60 min after propofol/fentanyl anaesthesia, there were no postoperative differences in cardiocirculatory parameters or blood gases. After isoflurane anaesthesia the time until the patients were able to give their names and perform the finger-nose test properly was longer than that after neurolept-anaesthesia or propofol anaesthesia. After propofol anaesthesia the patients could perform simple tests earlier and were more alert over the whole monitoring period than after isoflurane or neuroleptanaesthesia. On the other hand, the patients in the neuroleptanaesthesia group had fewer pain complaints than those in the two groups compared. DISCUSSION. None of the anaesthesia techniques used in this study showed an intraoperative advantage. This is not surprising since all anaesthetics, with the exception of ketamine, reduce intraocular pressure. The prerequisite, however, is careful monitoring of anaesthesia in elderly patients in order to avoid cardiocirculatory changes, mild hyperventilation and coughing and pressing at the end of the operation. Until this point in time no change in the depth of anaesthesia is allowed. Therefore, it seems on the whole that there are benefits from propofol-fentanyl anaesthesia because of the fact that in comparison with the rather techniques, elderly patients become alert again faster. However, sufficient postoperative pain therapy is necessary to free the patients of pain to the same degree as with neuroleptanaesthesia. In most cases peripherally acting analgesic substances with no interference with vigilance are sufficient.