After the routine pre-operative work-up, the patient was scheduled for coronary artery bypass grafting. He was premedicated with intramuscular morphine and oral lorazepam and anaesthesia was induced with midazolam, fentanyl, thiopentone and tracheal intubation was facilitated with vecuronium, without any difficulty.
Intra-operative monitoring consisted of electrocardiogram, arterial pressure, pulmonary capillary wedge pressure, cardiac output, pulse oximetry, end-tidal carbon dioxide, temperature, arterial blood gases and urine output. A midline sternal skin incision was made and sternotomy was attempted. The surgeon, who usually cuts the sternum with an electric saw with only one hand, had to use both his hands and all his strength to accomplish the split, such was the hardness of the bone. Two grafts in the form of left internal mammary artery to left anterior descending and reversed saphenous vein to right coronary artery were performed under cardiopulmonary bypass. During closure, the surgeon faced extreme difficulty in passing the steel wire through the thick bone while closing the sternum, so much so that two consecutive needles were broken in the process. The patient had an uneventful postoperative period and was finally discharged on the 7th postoperative day without any evidence of unstable sternum.
Fluoride is indeed one of the best examples of a double edged sword, i.e. if the diet is deficient in this trace element, one is likely to suffer from dental caries and weak bones, whereas on the other hand if one is exposed to a chronic excessive intake, one might suffer from fluorosis. This disorder is characterized by calcification of bony ligaments and tendons, and pathological increase in the amount and density of the bone. In extreme cases, features of spinal cord and root compression develop, resulting from narrowing of the spinal canal and intervertebral foramina due to excessive osteophytic activity . The patient may have limited motion at cervical or lumbothoracic intervertebral joints making him a possible candidate of difficult tracheal intubation and difficult subarachnoid, epidural, intercostal or paravertebral blocks. Fortunately, this form of excessive fluoride is not nephrotoxic as is the case with fluoride ions liberated as metabolites of the halogenated inhalational anaesthetic agents.