Unrecognized Pulmonary Venous Desaturation Early After Norwood Palliation Confounds Q̇p:Q̇s Assessment and Compromises Oxygen Delivery

• DOI: 10.1161/01.cir.103.22.2699
• Publication Date: 2012-06-12T00:09:32Z
• Authors: Roozbeh Taeed; Steven M. Schwartz; Jeffrey M. Pearl; Jenni L. Raake; Robert H. Beekman; Peter B. Manning; David P. Nelson
• Keywords: Oxygen delivery; Norwood procedure

Background —Hemodynamic stability after Norwood palliation often requires manipulation of pulmonary vascular resistance to alter the pulmonary-to-systemic blood flow ratio (Q̇p:Q̇s). Q̇p:Q̇s is estimated from arterial saturation (Sa o 2 ), a practice based on untested assumptions: constant systemic arteriovenous O difference and normal venous saturation. Methods Results —In 12 patients early (≤3 days) palliation, simultaneous arterial, superior vena caval (Ssvc (Spv ) oximetry was used test whether Sa accurately predicts Q̇p:Q̇s. Stepwise multiple regression assessed contributions , Ssvc Spv determination. correlated weakly with ( R =0.08, P <0.05). Inclusion improved prediction accuracy. Pulmonary desaturation <95%) observed frequently (30%), especially at Fi ≤0.21, but normalized higher or PEEP in all patients. In 6 patients, increased incrementally 0.17 0.50 determine this an effective means manipulate failed change predictably . 5 however, enhanced oxygen delivery, as demonstrated by improvement extraction. Conclusions —Sa poorly because variability A novel observation that occurred PEEP. Because unrecognized confounds assessment compromises judicious use inspired may be beneficial selected palliation.