A distensibilidade da veia jugular interna parece ser uma alternativa à distensibilidade da veia cava inferior para avaliar a responsividade a fluidos / Right internal jugular vein distensibility appears to be a surrogate marker for inferior vena cava vein distensibility for evaluating fluid responsiveness

RESUMOObjetivo:Investigar se a variação respiratória no diâmetro da veia cava inferior (ΔDVCI) e no diâmetro da veia jugular interna direita (ΔDVJID) se correlacionam em pacientes submetidos à ventilação mecânica.Métodos:Estudo clínico prospectivo realizado em uma unidade de terapia intensiva de um hospital universitário. Foram incluídos 39 pacientes mecanicamente ventilados e com instabilidade hemodinâmica. Os valores da variação do diâmetro da veia cava inferior e da variação do diâmetro da veia jugular interna direita foram avaliados por meio de ecografia. A distensibilidade da veia foi calculada como a razão de (A) Dmin - Dmax/Dmin e (B) Dmax - Dmin/média de Dmax - Dmin, e expressa como porcentagem.Resultados:Com ambos os métodos, observou-se correlação entre a variação do diâmetro da veia cava inferior e a variação do diâmetro da veia jugular interna direita: (A) r = 0,34, p = 0,04 e (B) r = 0,51, p = 0,001. Utilizando o ponto de corte de 18% para indicar responsividade a fluidos na variação do diâmetro da veia cava inferior, pelo o método (A), 16 pacientes foram considerados responsivos e 35 medições mostraram concordância (Kappa ponderado = 0,80). A área sob a curva ROC foi de 0,951 (IC95% 0,830 - 0,993; valor de corte = 18,92). Usando 12% como ponto de corte para a variação do diâmetro da veia cava inferior para indicar capacidade de resposta a fluidos, pelo método (B), 14 pacientes foram responsivos e 32 medições mostraram concordância (Kappa ponderado = 0,65). A área sob a curva ROC foi de 0,903 (IC95% 0,765 - 0,973; valor de corte = 11,86).Conclusão:As variações respiratórias nas dimensões da veia cava inferior e da veia jugular interna direita se correlacionaram e mostraram concordância significativa. Avaliação da distensibilidade da veia jugular interna direita parece ser uma alternativa à distensibilidade da veia cava inferior para avaliar a responsividade a fluidos.

ABSTRACTObjective:To investigate whether the respiratory variation of the inferior vena cava diameter (∆DIVC) and right internal jugular vein diameter (∆DRIJ) are correlated in mechanically ventilated patients.Methods:This study was a prospective clinical analysis in an intensive care unit at a university hospital. Thirty-nine mechanically ventilated patients with hemodynamic instability were included. ∆DIVC and ∆DRIJ were assessed by echography. Vein distensibility was calculated as the ratio of (A) Dmax - Dmin/Dmin and (B) Dmax - Dmin/ mean of Dmax - Dmin and expressed as a percentage.Results:∆DIVC and ∆DRIJ were correlated by both methods: (A) r = 0.34, p = 0.04 and (B) r = 0.51, p = 0.001. Using 18% for ∆DIVC, indicating fluid responsiveness by method (A), 16 patients were responders and 35 measurements showed agreement (weighted Kappa = 0.80). The area under the ROC curve was 0.951 (95%CI 0.830 - 0.993; cutoff = 18.92). Using 12% for ∆DIVC, indicating fluid responsiveness by method (B), 14 patients were responders and 32 measurements showed agreement (weighted Kappa = 0.65). The area under the ROC curve was 0.903 (95%CI 0.765 - 0.973; cut-off value = 11.86).Conclusion:The respiratory variation of the inferior vena cava and the right internal jugular veins are correlated and showed significant agreement. Evaluation of right internal jugular vein distensibility appears to be a surrogate marker for inferior vena cava vein distensibility for evaluating fluid responsiveness.

Subdiaphragmatic venous stasis and tissular hypoperfusion as sources of metabolic acidosis during passive portal-jugular and caval-jugular bypasses in dogs

Subdiafragmatic venous decompression during anhepatic stage of canine orthotopic liver transplantation attenuates portal and caval blood stasis and minimize hipoperfusion and metabolic acidosis observed with occlusion of portal and caval veins. During two hours, six dogs submitted to portal-jugular and caval-jugular passive shunts, with maintenance of arterial hepatic flow, were evaluated for pH, carbon dioxide tension (PCO2), base deficit (BD) and oxygen tension (PO2) in portal, caval and systemic arterial blood, as well as for increments of BD (DBD) in portal and caval blood. With a confidence level of 95 percent, the results showed that: 1. There were not changes of pH anDBD in portal and systemic arterial blood in the majority of studied times; 2. There was metabolic acidosis in caval blood; 3. The negative increments of BD (DBD) were higher in caval blood than in splancnic venous blood at T10, T30 and T105; and, 4. Deoxigenation of portal and caval blood were detected. Acid-base metabolism and oxigenation monitoring of subdiaphramatic venous blood can constitute an effective way to evaluate experimental passive portal-jugular and caval-jugular bypass in dogs.