Associations between survival and indicators of the degree of hemolysis. Correlations at 24 hours between survival time and (A) plasma haptoglobin levels (r = 0.61, P = .003); and (B) NO consumption capability of plasma (r = −0.76, P < .0001); were significant. In contrast, correlations between survival time and (C) total nontransferrin-bound iron levels (r = −0.28, P = .21) were not.