However, the reason for this may be that almost all the lesions were distal and the distance to be covered by the outgrowing axons was therefore not great. Secondary suture should be undertaken as soon as the primary wound has healed and the tissues are free from induration. Primary suture proved an unreliable operation, although some good results were seen. There are important technical reasons why secondary suture is more satisfactory. If, as is often the case, there has been intraneural damage it is much easier to recognize it some weeks after the injury than at the time, because it reveals itself as a palpable and, on section, visible zone of intraneural fibrosis. The resection can be planned accordingly. Furthermore, the epineurium becomes thickened after the injury, and after a few weeks is an ideal structure for holding fine sutures. Most of the repairs reported were secondary.Where there is associated damage to tendons it is best to repair them at the time of injury and simply to approximate the severed nerves. When mobilization of the digits is well advanced secondary suture of the nerves is performed without disturbance of the tendons, which, at the wrist, lie on a deeper plane, and continued movement of the fingers has no adverse effect on the nerve suture. REPERENCESBrooks. D. M (1Q55).

In the west of Scotland the incidence of dialysis encephalopathy has been confined to three geographical areas where the concentration of aluminium in the water supply is greatly increased owing to the addition of aluminium sulphate. Eight patients with encephalopathy who dialysed at home in these areas had greatly increased serum aluminium concentrations, and a significant correlation was found between serum aluminium concentrations and the concentrations of aluminium in the water supply. This study provides further evidence that the dialysis encephalopathy syndrome is due to aluminium intoxication, the major source of aluminium being the water supply from which dialysis fluid is prepared.

Plasma oxalate was measured on two occasions in 18 patients with end-stage renal failure on regular haemodialysis treatment: once while on a routine dose of vitamin C (100 mg/day) and subsequently after 2 weeks administration of a larger dose of vitamin C (500 mg/day). Pre- and post-dialysis concentrations were all markedly increased, reflecting the reduced glomerular filtration rate of end-stage renal failure. Both pre- and post-dialysis oxalate increased significantly following the increase in ascorbate dose but there was no significant correlation between plasma oxalate and ascorbate results. Considerations governing dosage of vitamin C in patients with chronic renal failure are discussed.

No abstract

Fifty-two patients with chronic renal failure undergoing hospital haemodialysis were given a single bolus dose of tinzaparin (Innohep, Leo Laboratories, UK) into the arterial side of the dialyser, for up to 43 consecutive dialyses. The mean tinzaparin dose at the beginning was 2,139 IU anti-Xa and at the end 2,186 IU anti-Xa. Overall, tinzaparin proved a satisfactory anticoagulant for 1,370 (96.0%) out of 1,427 dialyses. Significant clot formation was prevented in 1,326 (92.8%) out of 1,429 dialyses. The clinically effective dose was associated with a mean plasma anti-Xa activity 1 h after dosing of 0.4 IU/ ml and suppressed fibrinopeptide A formation for up to 4 h. Bleeding, from the skin or mucous membranes, was recorded at 27 (1.9%) of 1,408 dialyses. Prolonged fistula bleeding on completion of dialysis was recorded on only 20 occasions. Other haemorrhagic events included haematemesis, bruising and subconjunctival haemorrhage (each in 1 patient) and epis-taxis (2 patients). Three patients died during the study of causes considered unrelated to tinzaparin therapy, myocardial infarction (2 patients) and multiple myeloma. Other adverse events reported included vomiting (3 patients) and hypotension (3 patients). Three patients ceased treatment due to haematemesis, prolonged bleeding from fistula puncture and thrombosis of the arteriovenous access, respectively. A small, but statistically significant, increase within the normal reference range was recorded in the mean values for aspartate aminotransferase and alanine aminotransferase.