Systemic to Pulmonary Shunting in 93 Cyanotic Neonates

2018 ◽  
Vol 40 (1) ◽  
pp. 14-17
Author(s):  
Neale Nicola Kalis ◽  
Habib Ebrahim Al-Tarief ◽  
Suad Rashid Al Amer
Keyword(s):  
2014 ◽  
Vol 117 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Justin A. R. Lang ◽  
James T. Pearson ◽  
Arjan B. te Pas ◽  
Megan J. Wallace ◽  
Melissa L. Siew ◽  
...  

At birth, the transition to newborn life is triggered by lung aeration, which stimulates a large increase in pulmonary blood flow (PBF). Current theories predict that the increase in PBF is spatially related to ventilated lung regions as they aerate after birth. Using simultaneous phase-contrast X-ray imaging and angiography we investigated the spatial relationships between lung aeration and the increase in PBF after birth. Six near-term (30-day gestation) rabbits were delivered by caesarean section, intubated and an intravenous catheter inserted, before they were positioned for X-ray imaging. During imaging, iodine was injected before ventilation onset, after ventilation of the right lung only, and after ventilation of both lungs. Unilateral ventilation increased iodine levels entering both left and right pulmonary arteries (PAs) and significantly increased heart rate, iodine ejection per beat, diameters of both left and right PAs, and number of visible vessels in both lungs. Within the 6th intercostal space, the mean gray level (relative measure of iodine level) increased from 68.3 ± 11.6 and 70.3 ± 7.5%·s to 136.3 ± 22.6 and 136.3 ± 23.7%·s in the left and right PAs, respectively. No differences were observed between vessels in the left and right lungs, despite the left lung not initially being ventilated. The increase in PBF at birth is not spatially related to lung aeration allowing a large ventilation/perfusion mismatch, or pulmonary shunting, to occur in the partially aerated lung at birth.


1992 ◽  
Vol 72 (6) ◽  
pp. 2292-2297 ◽  
Author(s):  
K. C. Beck ◽  
J. Vettermann ◽  
K. Rehder

To determine the cause of the difference in gas exchange between the prone and supine postures in dogs, gas exchange was assessed by the multiple inert gas elimination technique (MIGET) and distribution of pulmonary blood flow was determined using radioactively labeled microspheres in seven anesthetized paralyzed dogs. Each animal was studied in the prone and supine positions in random order while tidal volume and respiratory frequency were kept constant with mechanical ventilation. Mean arterial PO2 was significantly lower (P less than 0.01) in the supine [96 +/- 10 (SD) Torr] than in the prone (107 +/- 6 Torr) position, whereas arterial PCO2 was constant (38 Torr). The distribution of blood flow (Q) vs. ventilation-to-perfusion ratio obtained from MIGET was significantly wider (P less than 0.01) in the supine [ln SD(Q) = 0.75 +/- 0.26] than in the prone position [ln SD (Q) = 0.34 +/- 0.05]. Right-to-left pulmonary shunting was not significantly altered. The distribution of microspheres was more heterogeneous in the supine than in the prone position. The larger heterogeneity was due in part to dorsal-to-ventral gradients in Q in the supine position that were not present in the prone position (P less than 0.01). The decreased efficiency of oxygenation in the supine posture is caused by an increased ventilation-to-perfusion mismatch that accompanies an increase in the heterogeneity of Q distribution.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
S M Binno ◽  
L Moderato ◽  
G Pastorini ◽  
B Matrone ◽  
D Aschieri ◽  
...  

Abstract We report a case of a 83-year-old female, who had an admission for dyspnea. Laboratory showed D-dimer 1000 ng/ml, haemoglobin 12.4 mg/dL, CPR 0.08mg/dl whereas on Arterial Blood Gas test she had hypoxia with respiratory alkalosis. In view of suspected pulmonary embolism, she underwent Thoracic Computed Tomography scan that excluded it. During the stay the patient seemed more symptomatic while in standing position(with SpO2s 89% while supine plunging to 50% while standing): ABGs were performed both standing (reservoir 15 l/min pH 7.50, pO2 37.2 mmHg, pCO2 37.1 mmHg, HCO3 28.9 mmol/l) and recumbent position (reservoir 15 l/min pH 7.47, pO2 65.5 mmHg, pCO2 35.1 mmHg, HCO3 25.6 mmol), showing a difference of 28 mmHg. Subsequently the patient underwent v/p pulmonary scintigraphy: no signs of pulmonary embolism though it revealed a multiple focus of capitation Tc-99m macro aggregated albumin in brain, thyroid and kidneys (IMG top), compatible for veno-arterial shunt. Trans-esophageal echocardiography (TOE) revealed a massive stretched patent foramen ovale (PFO) with continuous right-to-left shunting through the atria. The bubble test (IMG bottom) confirmed the presence of patency along with sudden passage of microbubbles through the foramen. Qp/Qs = 0.8, due to volume overload in the left atrium from the right atrium. The imaging along with clinical scenario confirmed the suspected diagnosis of platypnea-orthodeoxia, finding the patent foramen ovale as the anatomical cause. Platypnea-orthodeoxia syndrome is a clinical condition characterized by dyspnea. Typically blood oxygen saturation declines with standing position while it resolves with recumbent. The classification entails 3 groups: intracardiac shunting (most common presentation), pulmonary shunting, ventilation-perfusion mismatch. Presence of multiple focus of albumin macroaggregates outside the lungs in v/p scintigraphy examination is suggestive for veno-arteriuous shunt: without shunt, normally all the albumin aggregates are hampered in the lungs’ field. Images in bottom are taken in sequence from a single acquisition during the TOE, in one single cardiac beat. Here is depicted the evidence of the PFO, the influx of bubbles in the right atrium and the instantaneous and massive shunt of the bubbles across the interatrial septum, in the left atrium. Usually the diagnosis is performed within 55 years old: it is interesting how late the diagnosis occurred in this patient with such resounding clinical manifestation. Top Scintigraphy with ventilation and perfusion lung scan sequences. Next, scintigraphy with capitation of Tc-99m macro aggregated albumin in brain, thyroid and kidneys. Bottom, Transesophageal echocardiogram: images taken within the same heart beat proving right-to-left passage of bubble across the septum. Abstract P1317 Figure. Scintigraphy and Transesophageal echo


2011 ◽  
Vol 4 ◽  
pp. CCRep.S6805 ◽  
Author(s):  
Dike B. Ojji ◽  
Akinola O. Babalola ◽  
Ayodele O. Falase

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. Survival after the age of 12 years without corrective surgery is rare. We present the case of a 25 year-old man with uncorrected tetralogy of Fallot. Possible reasons for the longetivity in this patient are left ventricular hypertrophy and systemic to pulmonary shunting through internal mammary arteries.


1972 ◽  
Vol 37 (6) ◽  
pp. 582-587 ◽  
Author(s):  
J. Gilbert Stone ◽  
Stuart F. Sullivan

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