Case of Latent Nephritis Treated with Prednisolone

Abstract

CYANOTIC ATTACK IN FALLOT'S TETRALOGYBRDICTNAL 1325 precipitated in this case by the prolonged presence of a cardiac catheter in the pulmonary outflow tract. The diminution of the intensity of the systolic murmur indicated diminished flow across the pulmonary valve, but that this was not due to decreased systemic arterial resistance is shown by the sustained systemic blood pressure. Tachycardia was not responsible for the changes, as the heart rate remained rapid for some time after the disappearance of cyanosis and the return of a loud systolic murmur.Thus the findings in this case confirm Wood's (1958) hypothesis that the cyanotic attack is precipitated by temporarily increased obstruction at the pulmonary outflow tract, with greatly increased shunting of blood from right ventricle into aorta. Unlike Wood's cases, our patient showed only a slight drop in pulmonary artery pressure during the attack with no change in the pulse pressure, and deep coma was present with an arterial oxygen saturation of 52.5% (Wood states that coma ensues when the arterial oxygen saturation falls to about 20%). It would seem that the level of arterial desaturation at which the patient loses consciousness is, at least partly, dependent on the resting level of saturation, which in this patient was presumably normal or almost normal, in view of the absence of clinical cyanosis. The fact that the pulmonary artery pressure diminished only slightly might suggest that the obstruction to the pulmonary flow in our patient was less marked than in Wood's cases. It is significant, however, that the pulmonary artery pressure did not rise, which one would have expected were the obstruction to pulmonary flow produced by an increased pulmonary arterial resistance.The findings in this case indicate that the dangerous cyanotic attack may occur in those patients with Fallot's tetralogy with no clinical cyanosis, a finding which we have observed in other such cases (to be published).When faced with a cyanotic attack the practitioner may use procaine intravenously as an emergency measure, but for a sustained effect morphine would appear to be more suitable. It must be mentioned, however, that we have had patients in whom morphine has failed to stop the attack. Other narcotics might presumably be efficacious, and Wood has recommended cyclopropane anaesthesia. It must be stressed that oxygen administration is not, by itself, effective therapy. Summary A patient with "acyanotic Fallot's tetralogy developed a cyanotic (syncopal) attack during cardiac catheterization. The attack was probably precipitated by the prolonged presence of the catheter in the pulmonary outflow tract. The condition was studied haemodynamically, and it was believed that the attack was due to increased resistance to the flow of blood through the narrowed infundibulum. The treatment of the attack was difficult, and procaine intravenously was found to be effective, although the effect was not sustained. Morphine proved effective in relieving the attack.We thank Drs. M. J. Meyer, W. S...