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Objectives: Increased pulmonary dead space fraction (VD/VT) has been associated with prolonged mechanical ventilation after surgery for congenital heart disease. The association of VD/VT with clinical outcomes in neonates undergoing stage 1 palliation for single ventricle congenital heart disease has not been reported. We describe changes in VD/VT, differences in VD/VT based on shunt type (right ventricle to pulmonary artery conduit vs modified Blalock-Taussing shunt) and association of VD/VT with postoperative outcomes in patients undergoing stage 1 palliation., Design: Retrospective chart review for demographic, hemodynamics, outcome information, and VD/VT values were collected at 6-hour intervals during the first 48 postoperative hours in neonates undergoing stage 1 palliation. VD/VT was calculated using mixed expired CO2 (PeCO2) obtained from capnography and paired arterial blood gas CO2 values., Setting: Cardiac ICU in a tertiary care pediatric hospital., Patients: Newborns with single ventricle congenital heart disease undergoing stage 1 palliation during 2003-2004., Measurements and Main Results: Of the 51 patients, 31 had right ventricle to pulmonary artery and 20 had Blalock-Taussing shunt. Although VD/VT was lower in the Blalock-Taussing shunt group over all time points (p = 0.02), maximal VD/VT on day 1 (0.49 ± 0.07) and on day 2 (0.46 ± 0.08) were not different between the shunt groups. VD/VT decreased significantly over time in both shunt groups (p = 0.001 for right ventricle to pulmonary artery; p < 0.001 for Blalock-Taussing shunt). Higher maximal VD/VT during first 48 postoperative hours was independently associated with fewer ventilator (β = -26.6; p = 0.035) and hospital-free days in the first month after stage 1 palliation (β = -40.4; p = 0.002) after adjusting for potential confounders in a multivariable linear regression model., Conclusions: Increased pulmonary dead space exists early after stage 1 palliation operation for single ventricle congenital heart disease. Higher VD/VT during the first 48 postoperative hours was associated with longer duration of ventilation and hospital LOS and may be a useful marker of postoperative outcomes in this population.

Advances in technology have produced more sophisticated, diverse modes of mechanical ventilation. Efforts to reduce neonatal morbidity and mortality have led clinicians to use a myriad of ventilatory support modalities. It is imperative that critical care nurses become aware of the indications, advantages, and disadvantages of the new modes of ventilatory support. This article reviews respiratory physiology and presents new trends in neonatal mechanical ventilation.

It is the philosophy of our institution to provide primary surgical repair of complex congenital heart defects to avoid pulmonary and myocardial damage that occurs over time. Application of knowledge of the normal physiology and a clear understanding of the physiologic alterations of complex lesions are essential in understanding the effect of positive-pressure ventilation in complex CHD. The care and management of patients with CHD have a great deal to do with ventilatory management, which can be life-threatening when not fully understood but lifesaving when mastered. A dedicated team approach enhances communication and collaborative practice, which provides optimal patient management and outcome.