The effects of ventilation on left-to-right shunt and regional cerebral oxygen saturation: a self-controlled trial

Abstract

Background Increase of pulmonary vascular resistance (PVR) is an efficient method of modulating pulmonary and systemic blood flows (Qp/Qs) for patients with left-to-right (L-R) shunt, and is also closely associated with insufficient oxygen exchange for pulmonary hypoperfusion. So that it might be a preferred regime of maintaining arterial partial pressure of carbon dioxide tension (PaCO2) within an optimal boundary via ventilation management in congenital heart disease (CHD) patients for the inconvenient measure of the PVR and Qp/Qs. However, the appropriate range of PaCO2 and patient-specific mechanical ventilation settings remain controversial for CHD children with L-R shunt. Methods Thirty-one pediatric patients with L-R shunt, 1–6 yr of age, were included in this observation study. Patients were ventilated with tidal volume (VT) of 10, 8 and 6 ml/kg in sequence, and 15 min stabilization period for individual VT. The velocity time integral (VTI) of L-R shunt, pulmonary artery (PA) and descending aorta (DA) were measured with transesophageal echocardiography (TEE) after an initial 15 min stabilization period for each VT, with arterial blood gas analysis. Near-infrared spectroscopy sensor were positioned on the surface of the bilateral temporal artery to monitor the change in regional cerebral oxygen saturation (rScO2). Results PaCO2 was 31.51 ± 0.65 mmHg at VT 10 ml/kg vs. 37.15 ± 0.75 mmHg at VT 8 ml/kg (P < 0.03), with 44.24 ± 0.99 mmHg at VT 6 ml/kg significantly higher than 37.15 ± 0.75 mmHg at VT 8 ml/kg. However, PaO2 at a VT of 6 ml/kg was lower than that at a VT of 10 ml/kg (P = 0.05). Meanwhile, 72% (22/31) patients had PaCO2 in the range of 40-50 mmHg at VT 6 ml/kg. VTI of L-R shunt and PA at VT 6 ml/kg were lower than that at VT of 8 and 10 ml/kg (P < 0.05). rScO2 at a VT of 6 ml/kg was higher than that at a VT of 8 and 10 ml/kg (P < 0.05), with a significantly correlation between rScO2 and PaCO2 (r = 0.53). VTI of PA in patients with defect diameter > 10 mm was higher that that in patients with defect diameter ≤ 10 mm. Conclusions Maintaining PaCO2 in the boundary of 40-50 mmHg with VT 6 ml/kg might be a feasible ventilation regime to achieve better oxygenation for patients with L-R shunt. Continue raising PaCO2 should be careful. Trail registration Clinical Trial Registry of China (http://www.chictr.org.cn) identifier: ChiCTR-OOC-17011338, prospectively registered on May 9, 2017.

Middle-Range Theory of Ineffective Breathing Pattern in children with Congenital Heart Disease

“…The focal stimulus increases the carbon dioxide and hydrogen concentrations, acting as precipitation agents; that is, those that initially trigger the study phenomenon and cause an imbalance in the ventilation-perfusion process, triggering behaviors associated with the IBP Nursing diagnosis in order to compensate or correct the change in these values 8 , 10 - 11 .…”

Effect of change in tidal volume on left to right shunt across ventricular septal defect in children – A pilot study

“…A study by Li et al . [ 16 ] evaluated the effect of changing V T on left to right shunt-related echocardiographic parameters in patients undergoing VSD repair. A prospective study,[ 13 ] estimated left to right shunt in patients with isolated VSD using Doppler echocardiography and oximetry by cardiac catheterization.…”

“…Li et al . [ 16 ] compared the VTI of left to right shunt in the pulmonary artery and descending aorta (DA) by manipulating the ventilation parameters for pediatric patients with V T 10, 8, and 6 ml/kg. The effect on cerebral oxygen saturation (rScO 2 ) was noted by the alteration in V T. They had similar objectives as our study to determine the ventilation strategy with the ideal range of PaCO 2 which could provide optimal Qp/Qs with an adequate oxygen supply for children with the left to right shunt.…”

Teoría de Mediano Alcance del Patrón de Respiración Ineficiente en niños con cardiopatías congénitas

“…El estímulo focal aumenta las concentraciones de dióxido de carbono e hidrógeno, actuando como agentes precipitantes; es decir, aquellos que inicialmente desencadenan el fenómeno en estudio y provocan un desequilibrio en el proceso de ventilación-perfusión, desencadenando comportamientos asociados al diagnóstico de Enfermería de PRI con el fin de compensar o corregir la alteración de estos valores (8,(10)(11) .…”