Vasodilatory efficacy and impact of papaverine on endothelium in radial artery predilatation for cabg surgery: in search for optimal concentration

Abstract Objective: The aim of this study was to compare the efficacy of two different papaverine concentrations (0.5 mg/ml and 2 mg/ml) for vasospasm prevention and their impact on endothelium integrity. Methods: We have studied distal segments of radial arteries obtained by no-touch technique from coronary artery bypass graft (CABG) patients (n=10). The vasodilatory effect of papaverine (concentrations of 0.5 mg/ml and 2 mg/ml) was assessed in vitro, in isometric tension studies using ex vivo myography (organ bath technique) and arterial rings precontracted with potassium chloride (KCl) and phenylephrine. The impact of papaverine on endothelial integrity was studied by measurement of the percentage of vessel's circumference revealing CD34 endothelial marker. Results: 2 mg/ml papaverine concentration showed stronger vasodilatatory effect than 0.5 mg/ml, but it caused significantly higher endothelial damage. Response to KCl was 7.35±3.33 mN for vessels protected with papaverine 0.5 mg/ml and 2.66±1.96 mN when papaverine in concentration of 2 mg/ml was used. The histological examination revealed a significant difference in the presence of undamaged endothelium between vessels incubated in papaverine 0.5 mg/ml (72.86±9.3%) and 2 mg/ml (50.23±13.42%), P=0.002. Conclusion: Papaverine 2 mg/ml caused the higher endothelial damage. Concentration of 0.5 mg/ml caused better preservation of the endothelial lining.

Add-on treatment with nebulized hypertonic saline in a child with plastic bronchitis after the Glenn procedure / Tratamento adjuvante com nebulização de salina hipertônica em uma criança com bronquite plástica após a operação de Glenn

Plastic bronchitis (PB), although a rare cause of airway obstruction, has mortality rates up to 50% in children after Fontan-type cardiac surgery. We present the case of an 18-month-old female patient with PB following pneumonia. At 6 months of age, the patient underwent the Glenn procedure due to functionally univentricular heart. Fiberoptic bronchoscopy revealed complete blockage of the left bronchus by mucoid casts. Pharmacotherapy consisted of glucocorticosteroids, azithromycin, and enalapril maleate. The child also received nebulized 3% NaCl solution, which proved to be beneficial. In children submitted to Fontan-type procedures, physicians must be alert for PB, which can be triggered by respiratory tract infection.

A bronquite plástica (BP), embora uma causa rara de obstrução de vias aéreas, apresenta taxas de mortalidade de até 50% em crianças submetidas a cirurgia cardíaca do tipo Fontan. Apresentamos o caso de uma menina de 18 meses de idade com BP secundária a pneumonia. Aos 6 meses de idade, a paciente havia sido submetida à operação de Glenn devido a coração funcionalmente univentricular. A fibrobroncoscopia revelou obstrução completa do bronco esquerdo por moldes mucoides. A farmacoterapia consistiu em glicocorticosteroides, azitromicina e maleate de enalapril. Adicionalmente, a criança recebeu nebulização de solução de NaCl a 3%, que provou ser benéfica. Em crianças submetidas a operações do tipo Fontan, devemos nos manter alerta quanto à BP, que pode ser desencadeada por infecção do trato respiratório.