Changes of Lung Compliance in Pediatric Patients after Surgical Correction of Left to Right Shunt

Yoo, Eun Sook; Kwak, Young Lan; Nam, Sang Beom; Kim, Jaehyung; Choi, Seung Ho; Han, Sang Gun; Bang, Seo Ouk

Abstract

BACKGROUND
Low values of lung compliance have been reported in patients with increased pulmonary blood flow due to intracardiac left to right(L-R) shunt. The compliance had returned to within normal limits 4 to 6 weeks after surgical correction of the shunt. We investigated whether lung compliance was improved immediately after surgical correction of the shunt.
METHODS
Fifty four pediatric patients who were undergoing repair of intracardiac L-R shunt were evaluated. Lung compliance, arterial oxygen tension(PaO2) and arterial to end-tidal carbon dioxide tension difference(Pa-ETCO2) were measured after induction of anesthesia and at the completion of surgery. Left atrial pressure(LAP) was monitored. Lung compliance and end-tidal carbon dioxide tension were measured by monitoring system built in Cato anesthetic ventilator system.
RESULTS
Lung compliance was significantly lower after surgery(6.57+/-6.46 ml/mbar) than after induction of anesthesia(7.71+/-7.18 ml/mbar). After surgery, PaO2 was significantly decreased and Pa-ETCO2 significantly increased than after induction of anesthesia. The decrease in lung compliance after surgery significantly correlated with a decrease in PaO2(r=0.43) and an increase in Pa-ETCO2 (r=0.47) but not correlated with LAP.
CONCLUSIONS
Although surgical correction of intracardiac L-R shunt reduces pulmonary blood flow, the lung compliance decreases in immediate postoperative period. Therefore a deterioration of postoperative lung compliance may need judicious management for pulmonary and hemodynamic instability.