An Analytical Study of Splenectomised Cases after Traumatic Rupture of Healthy Spleens

Circulating nucleated red blood cells following splenectomy in a patient with congenital dyserythropoietic anemia

A 24-year-old white female with a 10-year history of juvenile rheumatoid arthritis and splenomegaly developed numerous circulating nucleated red blood cells (NRBC) following splenectomy for chronic abdominal pain. Subsequent evaluation revealed the presence of a congenital dyserythropoietic anemia (CDA) with atypical features. Circulating NRBCs have been reported following splenectomy in three other cases of CDA, each of which had atypical features and did not fit into the customary classification of types I-IV. Follow-up of our patient at 4 years revealed no untoward consequences of persistent NRBCs in her circulation.

Postsplenectomy sepsis and its mortality rate: actual versus perceived risks

A collective critical review of the literature on postsplenectomy sepsis from 1952 to 1987 has been undertaken. The reports cover a cohort of 12,514 patients undergoing splenectomy but of these only 5902 reports were sufficiently detailed to allow a useful analysis. The incidence of infection after splenectomy in children under 16 years old was 4.4 per cent with a mortality rate of 2.2 per cent. The corresponding figures for adults were 0.9 per cent and 0.8 per cent respectively. The present analysis of well documented patients has shown that severe infection after splenectomy for benign disease is very uncommon except in infants (infection rate 15.7 per cent) and children below the age of 5 years (infection rate 10.4 per cent). Many of these reported postsplenectomy infections may have been coincidental. It is also apparent that children contract a different type of infection after splenectomy than adults, predominantly a meningitis which is less frequently fatal. Adults, in contrast, appear to develop a septicaemic type of illness associated with a higher mortality rate. This survey has also shown that children are reported to be more susceptible to pneumococcal sepsis than to infection caused by any other organism. Although the removal of the spleen in otherwise normal people does not appear to be associated with an increased frequency of infection, the presence of a coexistent disorder, notably hepatic disease, can increase the risk substantially.

Mechanisms regulating the cardiac output response to cyanide infusion, a model of hypoxia

When tissue metabolic changes like those of hypoxia were induced by intra-aortic infusion of cyanide in dogs, cardiac output began to increase after 3 to 5 min, reached a peak (220% of the control value) at 15 min, and returned to control in 40 min. This pattern of cardiac output rise was not altered by vagotomy with or without atropine pretreatment. However, this cardiac output response could be differentiated into three phases by pretreating the animals with agents that block specific activities of the sympatho-adrenal system. First, ganglionic blockade produced by mecamylamine or sympathetic nerve blockade by bretylium abolished the middle phase of the cardiac output seen in the untreated animal, but early and late phases still could be discerned. Second, beta-adrenergic receptor blockade produced by propranolol shortened the total duration of the cardiac output rise by abolishing the late phase. Third, when given together, propranolol and mecamylamine (or bretylium) prevented most of the cardiac output rise that follows the early phase. When cyanide was given to splenectomized dogs, the duration of the cardiac output response was not shortened, but the response became biphasic, resembling that seen after chemical sympathectomy. A similar biphasic response of the cardiac output also resulted from splenic denervation; sham operation or nephrectomy had no effect on the monophasic pattern of the normal response. Splenic venous blood obtained from cyanide-treated dogs, when infused intraportally, caused an increase in cardiac output in recipient dogs; similar infusion of arterial blood had no effects. THESE RESULTS SUGGEST THAT THE CARDIAC OUTPUT RESPONSE TO CYANIDE INFUSION CONSISTS OF THREE COMPONENTS: an early phase, related neither to the autonomic nervous system nor to circulating catecholamines; a middle phase, caused by a nonadrenergic humoral substance released from the spleen by sympathetic stimulation; and a late phase, dependent upon adrenergic receptors but not upon sympathetic transmission.