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A3727 - My Baby Gave Me Hypoxemia
Author Block: D. Aponte1, M. A. Farinacci Vilaro2, M. J. Cruz Caliz3, K. X. Rivera4, J. R. Adorno5; 1Internal Medicine, San Juan City Hospital, San Juan, PR, United States, 2Internal Medicine, San Juan City Hospital, San Juan, Puerto Rico, 3Pulmonary and Critical Care, San Juan City Hospital, Penuelas, PR, United States, 4Pulmonary and Critical Care, San Juan City Hospital, San Juan, Puerto Rico, 5Pulmonary and Critical Care, San Juan City Hospital, San Juan, PR, United States.
Milder degree of intrapulmonary shunting can occur in pregnant woman which manifestation can be overlooked as side effect of pregnancy. Analogous to what may be occurring to hepato-pulmonary syndrome, intrapulmonary vascular dilatations (IPVDs) can cause diverse degree of intravascular shunting and its resultant hypoxemia. By different pathways, progesterone and estrogen have direct influence on vasodilation activity. We present the case of 27 year old G2P1C0A0 woman, 35 weeks of gestation with asthma, with complaint of shortness of breath and nonproductive cough at night without constitutional symptom of two months evolution, which have been worsening. Symptom was overlook as part of dyspnea of pregnancy in view of uneventful first pregnancy. Physical examination shows cyanosis, tachypnea, tachycardia and clear lungs to auscultation. Pulmonary function test (PFTs) and arterial blood gases (ABGs) demonstrate hypoxemia and low diffusion capacity of the lungs for carbon monoxide (DLCO). Peripheral oxygen saturation decreased up to 84% with minimal exertion. EKG showed First Degree AV Block, Chest X-Ray and laboratory workup including rheumatologic, viral and cardiac enzymes were normal. Imaging including transthoracic echocardiogram, lower extremities venous doppler, Chest CT with IV contrast and pulmonary angiography came back negative for pulmonary embolism, pulmonary hypertension or arteriovenous malformation. Work up rule out common etiologies of hypoxemia. Since no improvement of hypoxemia with respiratory therapies and steroids, ABGs were done at 21% and later 100% oxygen revealing shunt fraction of 17%, suggestive of right to left shunt. Echocardiography with bubble contrast at the fifth heartbeat bubbles passed into the left side of the heart which was indeterminate for pulmonary vs. cardiovascular shunt origin for hypoxemia. Labor was induced by the 37 week but symptoms persisted and patient remained oxygen dependent. Cardiac MRI was negative for cardiovascular anomalies. As the weeks past, patient felt better. Hypoxemia improved. Supplemental oxygen wasn’t required. ABGS were normal, repeated PFTS remarkable for low but improved DLCO. The importance of this case is that there is only two reported cases of hypoxemia that has developed during pregnancy with similar clinical presentation suggestive of intrapulmonary shunting, after all common etiology have been ruled out. This mismatch occurs secondary to reduced diffusion from IPVDs. Therefore, hypoxemia severity can be correlated to the degree of intravascular shunting, which in our case was directly related to female hormones during and after pregnancy. The lack of evidence per imaging can be explain by microscopic vascular changes since cardiovascular origin was rule out.