96 Discussion 



variety you get figures up to 16 m-equiv./l. or more with survival, though 

 not for long. I have not personally encountered that, but it has been 

 seen in the Hospital for Sick Children, Great Ormond Street. 



Young: I think there is a much simpler explanation for the young 

 infant's rapid rise in serum potassium under conditions of stress. The 

 babies with the adrenogenital syndrome feel poorly and vomit ; therefore 

 they take in very little water and become dehydrated. Their blood urea 

 goes sky high at the same time as the serum potassium, and I think that 

 both are due to a rapid rate of cellular breakdown secondary to the dehy- 

 dration. I have no real proof of this, but all neonates becoming dehy- 

 drated very quickly show a high serum potassium level. 



Milne: In these cases in babies with high serum potassium, is the 

 myocardium less sensitive to the hyperkalaemia? This could be inferred 

 from the work of Widdowson and McCance (1956. Clin. Sci., 15, 361) on 

 serum potassium in foetal pigs. Anyone with experience of hyper- 

 kalaemia in acute renal failure in adults would find very severe ECG 

 changes long before the serum potassium reached 10 m-equiv./l., and 

 death usually occurs very shortly after the potassium reaches 10 

 m-equiv./l. These high figures rather startle me; I would like to know 

 what is happening to the ECG during the period of hyperkalaemia. 



Davson : The effect of potassium on the heart is linked with that of 

 calcium. It may be that over long periods the calcium might rise too 

 and tend to compensate for the raised potassium. 



Scribner : We have made some studies on dogs and we could not greatly 

 increase the tolerance of the dog to hyperkalaemia by giving calcium. 

 Large doses of calcium increased tolerance no more than 1 m-equiv./l. 



Adolph : This unanswered problem may leave us with an age difference 

 in the susceptibility of the heart to potassium. 



Young: Once the potassium goes up towards 10 m-equiv./l. in babies 

 they become desperately ill and they sometimes die. I do not think they 

 have any better tolerance to these very high serum potassium levels than 

 adults. If you take infants with the adrenogenital syndrome off all their 

 treatment in order to confirm the diagnosis, which may be difficult in 

 young males, it is a very frightening experience to see the heart mis- 

 behaving with both the clinical effects and the ECG changes of hyper- 

 kalaemia. 



McCance: You seem to have found something in which the infant 

 appears to react in the same way as the adult. 



Young : Kerpel-Fronius has over-emphasized, perhaps, the differences 

 in the physiology of the infant, but his points are all intended to under- 

 line the differences in the effect of stress on the infant. In the treatment 

 of infants, sometimes the physiologist's point of view has made the 

 clinician oversensitive. He is frightened to give infants the treatment 

 that would be appropriate for adults because of the differences in the 

 physiology of the infant — whereas the clinical condition must and can be 

 treated effectively as long as the relatively minor differences in physio- 

 logy are borne in mind. 



There is one point I should like to make which refers to the papers by 

 Prof. Adolph and Dr. Swyer. It seems to me, since the baby tends to 



