RESUMO
The haemoglobin content of gastric aspirates can be quantitated by conversion of non-fluorescent haem to fluorescent porphyrins by heating gastric aspirates with oxalic acid and ferrous sulphate. Recovery of haemoglobin added to gastric aspirates was 92 +/- 9%, variation coefficient, n = 52, day to day variation less than 8%. This method was used to calculate blood (haemoglobin) loss in 211 (24 hours) gastric aspirates obtained from 58 intensive care patients. Gastric blood loss was also measured by the 51Cr radiolabelled erythrocytes method in the same samples. There was a good linear correlation (r = 0.942, p less than 0.001) between the two methods. The fluorimetric method of quantitating haem is therefore suitable for detecting and measuring blood loss in gastric contents.
Assuntos
Suco Gástrico/análise , Hemoglobinas/análise , Cromatografia Líquida de Alta Pressão , Radioisótopos de Cromo , Humanos , Indicadores e Reagentes , Inalação , Espectrometria de Fluorescência/métodosRESUMO
The effects of intragastric prostaglandin E2 (PGE2) on the occurrence of acute GI hemorrhage in intensive care patients were investigated in a prospective, double-blind, placebo-controlled study. Ninety patients with two or more risk factors (major surgery, multiple trauma, respiratory insufficiency, renal insufficiency, jaundice, hypotension, peritonitis, sepsis) were randomized for treatment with either PGE2 (0.5 mg) or placebo, administered every 4 h via a nasogastric tube. Blood loss in gastric aspirates was measured by 51Cr-erythrocyte labeling and a peroxidase test (orthotolidine). Of 57 patients who could be evaluated, 29 received PGE2 and 28 received placebo. Hemorrhage occurred in nine PGE2 patients and 13 placebo-treated patients, not a significant difference. The occurrence of hemorrhage was related to the number of risk factors, and GI hemorrhage was rarely the major factor determining mortality. Results of the orthotolidine test were not positively correlated with those of erythrocyte labeling, indicating that peroxidase tests should not be relied upon to detect blood in gastric aspirates.
