Renal Function in Respiratory Failure 267 



workers (1952). A moderate degree of urea retention, pre- 

 sumably on the basis of relative renal ischaemia, is common 

 in cor pulmonale (Simpson, 1957), as in other forms of heart 

 failure. In patients dying from heart failure, the output of 

 urine may be reduced to below 500 ml. /day, but complete 

 suppression of urine does not seem to have been recorded, 

 even in the terminal stages. It is perhaps of some interest, 

 therefore, that over the past ten years we have seen two 

 patients, both with cor pulmonale, who became anuric 

 (Black and Stanbury, 1958). One of them, a girl of 20 with 

 widespread bronchiectasis and a terminal bronchopneumonia, 

 had an eight-day period of extreme oliguria, during which 

 her blood urea rose to 158 mg./lOO ml. She was treated 

 conservatively, urine was again formed, and the blood urea 

 fell to 76 mg./lOO ml. She continued to pass considerable 

 amounts of dilute urine until her death a week after the end 

 of the anuric period. The second patient, a man of 44, passed 

 no urine for over 24 hours, and had no urine in his bladder 

 after death. Both these patients had hypotension and cold 

 extremities, and were presumably in the low-output phase of 

 cor pulmonale; but cardiac output could not of course be 

 measured. Both of them had central cyanosis, but only the 

 second had a raised pCOg in the plasma. The main factor in 

 causing anuria was probably renal ischaemia, but this may 

 have been aggravated by arterial desaturation. 



Both these patients had hyperkalaemia and low plasma 

 sodium. This association is fairly common in patients with 

 acute renal failure, but we have seen it also in the absence of 

 renal failure and it may possibly represent a loss of potassium 

 from cells, with partial replacement by sodium. 



These observations in patients with terminal cor pulmonale 

 are possibly of little more than academic interest; but they 

 perhaps constitute yet another argument for the early treat- 

 ment of intercurrent infections in patients with emphysema ; 

 such intercurrent infections may be apyrexial, and attended 

 by little apparent reaction, but they can precipitate the 

 patient into terminal low-output failure. 



