1/3. Reversal of dysthyroid optic neuropathy following orbital fat decompression.AIMS: To document the successful treatment of five patients with dysthyroid optic neuropathy by orbital fat decompression instead of orbital bone decompression after failed medical therapy. methods: Eight orbits of five patients with dysthyroid optic neuropathy were selected for orbital fat decompression as an alternative to bone removal decompression. Treatment with systemic corticosteroids and/or orbital radiotherapy was either unsuccessful or contraindicated in each case. All patients satisfied clinical indications for orbital bone decompression to reverse the optic neuropathy. High resolution computerised tomographic (CT) scans were performed in all cases and in each case showed signs of enlargement of the orbital fat compartment. As an alternative to bone decompression, orbital fat decompression was performed on all eight orbits. RESULTS: Orbital fat decompression was performed on five patients (eight orbits) with optic neuropathy. Optic neuropathy was reversed in all cases. There were no cases of postoperative diplopia, enophthalmos, globe ptosis, or anaesthesia. All patients were followed for a minimum of 1 year. CONCLUSIONS: In a subset of patients with an enlarged orbital fat compartment and in whom extraocular muscle enlargement is not the solitary cause of optic neuropathy, fat decompression is a surgical alternative to bony decompression.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
2/3. Thyroid storm prior to induction of anaesthesia.A 53- year-old woman without a previous history of thyroid disease was scheduled for mastectomy. On arrival in the operating theatre unpremedicated she appeared restless and tachycardic. midazolam and fentanyl was administered intravenously. Concomitantly, sinus tachycardia developed and a flush reaction was observed in the skin of the thoracic region and neck. The blood pressure increased to 265/160 mmHg and the patient lost consciousness and became apnoeic. unconsciousness and apnoea lasted for approximately 25 min and the operation was postponed. Further investigations revealed an elevated serum free thyroxine level and suppressed serum thyrotropin diagnostic of hyperthyroidism. The serum TSH receptor antibody concentration was elevated, indicating that the patient was suffering from Graves' disease. We present a case of a previously unknown hyperthyroid patient, with breast cancer, presenting as a thyroid crisis on induction of anaesthesia. Although being quite a rare occurrence, unsuspected thyroid disease should be borne in mind when an agitated patient enters the operating theatre.- - - - - - - - - - ranking = 5keywords = anaesthesia (Clic here for more details about this article) |
3/3. Visual evoked potential monitoring of optic nerve function during surgery.A study was made with intra-operative flash--visual evoked potentials (VEP) monitored using a fibre-optic/contact lens photo stimulator in 57 patients undergoing intra-orbital surgical procedures with potential risk to the optic nerve. The VEPs recorded under enflurane and nitrous oxide anaesthesia did not differ significantly in latency or amplitude from the pre-operative recordings. Transient abolition of the VEP was seen under many circumstances and did not correlate with the outcome of surgery, but absence of a previously normal VEP for more than four minutes during surgical manipulation within the orbit did show a correlation with post operative impairment of vision. The technique provides early warning to the surgeon of threats to the integrity of the optic nerve.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |