Refractory amiodarone-associated thyrotoxicosis: an indication for thyroidectomy.

BACKGROUND: Tasmania is an area of endemic iodine deficiency. Amiodarone is a class III anti-arrhythmic drug that is widely used for the management of ventricular and supraventricular tachydysrhythmias. Individuals from areas of endemic iodine deficiency appear more likely to manifest hyperthyroidism following amiodarone therapy, whereas hypothyroidism is a more frequent complication in iodine-replete communities. METHODS: Cases series. The clinical and biochemical response to medical and surgical management of five consecutive Tasmanian patients presenting with severe type-II amiodarone-associated thyrotoxicosis was reviewed. RESULTS: Five patients were identified. Combinations of antithyroid therapy including propylthiouracil, lithium carbonate, dexamethasone and cholestyramine were used. Thyroidectomy was required in two cases (40%) due to severe unremitting thyrotoxicosis despite combined drug regimens. Anaesthesia and total thyroidectomy were undertaken without complication despite the presence of severe hyperthyroidism at the time of surgery. In both cases thyroid histopathology demonstrated degenerative and destructive follicular lesions with multinuclear cell infiltrate and focal fibrosis. CONCLUSION: Amiodarone-associated thyrotoxicosis may be severe and refractory to medical therapy. Despite the potential risks of anaesthesia associated with uncontrolled thyrotoxicosis, thyroidectomy should be considered in the setting of life-threatening thyrotoxicosis.

Delayed intraperitoneal ureteric rupture following blunt abdominal trauma: case report.

Ureteric injury is uncommon and mostly follows penetrating trauma or surgical injury. Ureteric rupture following blunt abdominal trauma is rare, there being only a few reported cases. The case described here, in which blunt abdominal trauma resulted in delayed intraperitoneal rupture, appears to be the first report of this type of injury in blunt trauma.

Prognostic significance of ST potentials determined by body surface mapping in inferior wall acute myocardial infarction.

Electrocardiographic body surface mapping on admission to coronary care has been shown to predict prognosis in a previous study of 100 patients with inferior wall acute myocardial infarction (AMI). A further 98 patients with first inferior wall AMI were now studied by body surface mapping on admission to coronary care to confirm that both the spatial distribution or map pattern of ST-segment potentials and the precise measurement of the maxima and minima are of prognostic significance. Each ST-segment map was compared by correlation coefficient to the average map pattern of the 4 groups derived in a previous study and placed in the group with the highest correlation coefficient. Analysis of these groups against outcome confirmed that the group dominated by a large area of marked anterior ST depression was associated with a high rate of complications and a significantly lower survival free of coronary artery bypass grafting (p less than 0.01). Patients in this group had more extensive and severe coronary artery disease than patients in the other groups. Increasing values of maximal ST depression correlated with mortality and complication rates. The extent by which the magnitude of ST-segment depression exceeded the magnitude of ST-segment elevation correlated with mortality and incidence of left ventricular failure. The results confirm the findings of the original study. Body surface mapping is of prognostic significance in inferior wall AMI.

Brain resuscitation and protection.

No drug that is used for brain protection after global brain ischaemia as a result of cardiac arrest has been shown to be of benefit. Barbiturate agents have been proved not to be beneficial whereas studies of calcium-channel blocking drugs are inconclusive. Hypothermia, haemodilution and mechanical hyperventilation are not of proven benefit. Immediate defibrillation with rapid restoration of blood pressure is the best method to improve the neurological outcome after a cardiac arrest. After severe head injury, prompt emergency care to restore ventilation, oxygenation and blood pressure improves the neurological outcome. The early evacuation of extracerebral intracranial haematomas also improves the outcome. Corticosteroid therapy does not improve the outcome. The monitoring of intracranial pressure and the control of increased intracranial pressure by hyperventilation, cerebrospinal-fluid drainage and mannitol, frusemide and barbiturate therapy appear to improve the outcome after a severe head injury, although this has not been proved by randomized controlled studies.

Spatial distribution and prognostic significance of ST segment potential determined by body surface mapping in patients with acute inferior myocardial infarction.

We investigated the mechanism and significance of ST segment changes in inferior infarction by studying 100 patients with acute inferior infarction in whom body surface maps were recorded on admission. The magnitude of the maximum ST segment elevation (denoted Vmax) and magnitude of the maximum ST segment depression (denoted Vmin), as well as the ST depression on the standard 12-lead electrocardiogram were analyzed against morbidity and mortality (at a median follow-up time of 14 months). A value obtained by subtracting Vmax from Vmin correlated (p less than .0002) with outcome. Correlations were also found between Vmin and complications, Vmin and mortality, and between increasing levels of ST depression on the 12-lead electrocardiogram and mortality. The maps were also studied by grouping the 100 ST segment map patterns into five groups by cluster analysis techniques. One group showed marked anterior negativity and had 37% mortality compared with an overall 5% mortality for the remaining groups. The limited arteriographic and autopsy data available indicated that the findings of a diseased artery or arteries corresponded with the results of mapping. The mean map patterns of the five groups showed that, in most patients with inferior infarction, the standard chest leads V1 to V6 are over a region of steep voltage gradient. Small changes in the position of the standard chest lead can cause large changes in the displayed potentials. This study indicates that patients at high risk after acute inferior infarction can be identified by surface mapping on admission to the coronary care unit.

Misplacement of nasogastric tubes and oesophageal monitoring devices.

Accidental invasion of the trachea past an inflated cuff may occur more easily when endotracheal tubes with soft, low pressure cuffs are used. A new, simple and safe technique for blind oesophageal intubation is outlined. Two cases of accidental invasion of the trachea by oesophageal tubes are described.

Cardiac rupture complicating acute myocardial infarction in presence of normal electrocardiogram.

Cardiac rupture following acute myocardial infarction occurs most frequently in patients with electrocardiographic evidence of transmural infarction. Unusual presentations of cardiac rupture need immediate recognition to enable successful surgical treatment. An unusual case is presented of cardiac rupture complicating acute myocardial infarction despite a normal electrocardiogram prior to the rupture.