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Biomedical subjects

S M Dixon

Publications and source records attributed to S M Dixon.

6 recordsLinked to original sources
PubMed1985

Acute renal dysfunction after major arteriography.

The incidence of acute renal dysfunction (ARD) after major arteriography was evaluated by assessment of the change in serum creatinine in 364 patients undergoing arteriography. Major arteriography was defined as abdominal aortography, abdominal aortography with lower-extremity runoff, aortic arch studies, or aortic arch plus selective carotid angiography. The influence of the volume of contrast material received, hydration, and associated risk factors was evaluated. In the entire group, the frequency of postarteriographic ARD was 7.1%. Although most patients recovered, 1.4% required renal dialysis. The frequency of renal dysfunction was significantly higher in patients with preexisting renal disease (14.8%), and 3.7% of these patients went on to require dialysis. In the total group and in those with normal renal function prearteriographically, the frequency of ARD was found to be related to the volume of iodinated contrast material received. Hydration before, during, and after angiography did not prevent this complication. Several risk factors, namely preexisting renal disease, advanced age, volume of contrast material used, type of study performed, diabetes mellitus, and coexistent heart disease were found to be associated with a statistically significant increased risk of postangiographic ARD.

Acute Kidney Injury↗
PubMed1983

Risk of renal failure after major angiography.

In 400 patients who underwent major aortography, acute renal dysfunction (ARD) occurred in 11.3%. Of the group with normal renal function before the procedure, 8.2% had ARD and 0.8% required dialysis. Patients with prior abnormal renal function had a 41.7% incidence of ARD, and 8.3% required dialysis as a result of angiography. Vigorous intravenous hydration was used in all patients but did not completely prevent renal problems. Two risk factors not previously emphasized were the injection site (higher risk with abdominal aortic studies) and presence of congestive heart failure requiring treatment with digoxin. Other notable risk factors included contrast load and age. These results emphasized that even with modern contrast agents and application of current concepts of treatment, there remains a risk of renal injury with major angiography.

Acute Kidney Injury↗
PubMed1983

Fate of aortic graft removal.

Reoperation to remove an aortic graft was performed in 18 patients. The need for removal was infection in the majority. A changing flora was seen in aortic graft infection with gram-negative organisms predominating. Despite a standardized approach with total graft removal, aortic closure, and extraanatomic reconstruction, amputation and mortality rates remain unacceptably high. A new approach to this problem is needed, and further trials with autogenous reconstruction appear warranted.

Aged↗
PubMed1979

Observations on the rate and mechanism of hemolysis in individuals with Hb Zürich [His E7(63)beta leads to Arg]: II. Thermal denaturation of hemoglobin as a cause of anemia during fever.

Individuals with unstable hemoglobins may become more anemic during episodes of intercurrent viral or bacterial infections. Pathophysiologic mechanisms that are responsible for this phenomenon have not been elucidated. Recently we observed a patient with Hb Zürich [His E7(63)beta leads to Arg] whose anemia worsened during a febrile episode characterized by temperatures ranging between 40 degrees and 41 degrees C, splenomegaly, and the appearance of Heinz bodies in the circulating erythrocytes. There was no history of self-medication and no drugs were administered during hospitalization. To determine the effect of a 3 degrees to 4 degrees temperature elevation above the physiologic range on the rate and degree of Heinz body formation, normal (Hb A) and Hb Zürich bloods were incubated in vitro at 4 degrees C, 37 degrees C, and 41 degrees C for 3, 6, 12, and 24 hours and stained for two minutes at the end of each incubation period with rhodanile blue. No Heinz bodies appeared at 4 degrees C. The rate of Heinz body formation was significantly greater in Hb Zürich than normal blood, both at 37 degrees C and 41 degrees C. These observations suggest that in vivo exposure of red cells to temperatures in the biologic range of fever may contribute to the worsening of anemia that occurs during infections in individuals with unstable hemoglobins. Incubating whole blood at 41 degrees C for three hours and staining with rhodanile blue for two minutes appears to be a simple and effective screening test for Hb Zürich and possibly the other unstable hemoglobins. Also the technique is semi-quantitative and may be useful as a research tool for defining factors altering the in vivo stability of the unstable hemoglobins.

Adolescent↗