TY - JOUR
T1 - Unrecognized pulmonary venous desaturation early after Norwood palliation confounds Q̇p:Q̇s assessment and compromises oxygen delivery
AU - Taeed, Roozbeh
AU - Schwartz, Steven M.
AU - Pearl, Jeffrey M.
AU - Raake, Jenni L.
AU - Beekman, Robert H.
AU - Manning, Peter B.
AU - Nelson, David P.
PY - 2001/6/5
Y1 - 2001/6/5
N2 - 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 often estimated from arterial saturation (Sao2), a practice based on 2 untested assumptions: constant systemic arteriovenous O2 difference and normal pulmonary venous saturation. Methods and Results - In 12 patients early (≤3 days) after Norwood palliation, simultaneous arterial, superior vena caval (Ssvco2), and pulmonary venous (Spvo2) oximetry was used to test whether Sao2 accurately predicts Q̇p:Q̇s. Stepwise multiple regression assessed the contributions of Sao2, Ssvco2, and Spvo2 to Q̇p:Q̇s determination. Sao2 correlated weakly with Q̇p:Q̇s (R2=0.08, P<0.05). Inclusion of Ssvco2 and Spvo2 improved Q̇p:Q̇s prediction accuracy. Pulmonary venous desaturation (Spvo2 <95%) was observed frequently (30%), especially at Fio2 ≤0.21, but normalized with higher Fio2 or PEEP in all patients. In 6 patients, Fio2 was increased incrementally from 0.17 to 0.50 to determine whether this was an effective means to manipulate Q̇p:Q̇s. Q̇p:Q̇s failed to change predictably with increased Fio2. In 5 of 6 patients, however, higher Spvo2 and Sao2 enhanced systemic oxygen delivery, as demonstrated by improvement in oxygen extraction. Conclusions - Sao2 correlated poorly with Q̇p:Q̇s because of variability in Ssvco2 and Spvo2. A novel observation was that pulmonary venous desaturation occurred frequently early after Norwood palliation but normalized with higher Fio2 or PEEP. Because unrecognized pulmonary venous desaturation confounds Q̇p:Q̇s assessment and compromises Sao2 and oxygen delivery, judicious use of inspired oxygen and PEEP may be beneficial in selected patients early after Norwood palliation.
AB - 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 often estimated from arterial saturation (Sao2), a practice based on 2 untested assumptions: constant systemic arteriovenous O2 difference and normal pulmonary venous saturation. Methods and Results - In 12 patients early (≤3 days) after Norwood palliation, simultaneous arterial, superior vena caval (Ssvco2), and pulmonary venous (Spvo2) oximetry was used to test whether Sao2 accurately predicts Q̇p:Q̇s. Stepwise multiple regression assessed the contributions of Sao2, Ssvco2, and Spvo2 to Q̇p:Q̇s determination. Sao2 correlated weakly with Q̇p:Q̇s (R2=0.08, P<0.05). Inclusion of Ssvco2 and Spvo2 improved Q̇p:Q̇s prediction accuracy. Pulmonary venous desaturation (Spvo2 <95%) was observed frequently (30%), especially at Fio2 ≤0.21, but normalized with higher Fio2 or PEEP in all patients. In 6 patients, Fio2 was increased incrementally from 0.17 to 0.50 to determine whether this was an effective means to manipulate Q̇p:Q̇s. Q̇p:Q̇s failed to change predictably with increased Fio2. In 5 of 6 patients, however, higher Spvo2 and Sao2 enhanced systemic oxygen delivery, as demonstrated by improvement in oxygen extraction. Conclusions - Sao2 correlated poorly with Q̇p:Q̇s because of variability in Ssvco2 and Spvo2. A novel observation was that pulmonary venous desaturation occurred frequently early after Norwood palliation but normalized with higher Fio2 or PEEP. Because unrecognized pulmonary venous desaturation confounds Q̇p:Q̇s assessment and compromises Sao2 and oxygen delivery, judicious use of inspired oxygen and PEEP may be beneficial in selected patients early after Norwood palliation.
KW - Heart defects, congenital
KW - Hypoplastic left heart syndrome
KW - Lung
KW - Norwood operation
KW - Surgery
UR - http://www.scopus.com/inward/record.url?scp=0035810905&partnerID=8YFLogxK
U2 - 10.1161/01.CIR.103.22.2699
DO - 10.1161/01.CIR.103.22.2699
M3 - Article
C2 - 11390340
AN - SCOPUS:0035810905
SN - 0009-7322
VL - 103
SP - 2699
EP - 2704
JO - Circulation
JF - Circulation
IS - 22
ER -