Hypofibrinogenemia and inadequate heparin reversal are 2 important factors contributing to clot strength and perioperative hemorrhage after pediatric CPB. TEG may be a useful tool for predicting and guiding early treatment of mediastinal bleeding in this group.

No abstract

It is now possible using a simple correction factor to quantify the confounding effect of hyperchloraemia on both base deficit and bicarbonate in diabetic ketoacidosis. This bedside tool may be a useful adjunct to guide therapeutic interventions.

In 1935, Dale suggested that the identification of the chemical transmitter responsible for antidromic vasodilatation would be a useful approach to the problem of sensory transmission in the central nervous system since it is likely that the transmitter is the same at both ends of the sensory neurone. One of the difficulties in searching for the transmitter at central sensory endings is the lack of a specific pharmacological test for it. However, if the transmitter is also responsible for antidromic vasodilatation, it should be possible to detect it by its vasodilator activity in those organs in which antidromic vasodilatation can be elicited. This approach was used by Hellauer & Umrath (1947, 1948), who studied the effects of injecting extracts of dorsal and ventral roots into the rabbit's ear. As a result of their experiments they claim that: (1) dorsal roots contain a vasodilator substance which is neither acetylcholine nor histamine; this substance is absent from ventral roots; (2) sensory denervation increases the sensitivity of the rabbit's ear to the substance; (3) the vasodilator substance is enzymically destroyed when incubated for 20 hr, the enzyme activity being greatest in dorsal roots and less in ventral roots and preganglionic sympathetic fibres; (4) the enzyme is inhibited by strychnine.They conclude that the vasodilator substance is the transmitter liberated at sensory nerve endings.Since this claim is of far-reaching significance for the theory of central synaptic transmission we have repeated and extended their experiments and were able to confirm some, but not all, of their results. In our view, the eyidence now available is not sufficient to support the general conclusion of Hellauer & Umrath. METHODS Spinal root extract8Extracts were prepared from the spinal roots ofhorses which were dissected in the slaughter-house. The dissection was started about 25 min after the death of the animal and took 10 min for each horse. Starting at the last sacral segment, the ligamentum denticulatum was identified between * Beit Memorial Research Fellow.

The Paediatric Analgesia Wheel provides a time-efficient method of prescribing commonly used analgesic and anti-emetic drugs to children and results in improved accuracy when compared with using the BNFC.