Microvascular Pulmonary Emboli Secondary to Precipitated Crystals in a Patient Receiving Total Parenteral Nutrition

A patient with a history of a small-bowel transplant that was subsequently resected required total parenteral nutrition for nutritional supplementation. While receiving therapy, he developed chest tightness, shortness of breath, and fever. The chest radiograph showed bilateral reticulonodular opacities, and the high-resolution CT scan demonstrated diffuse, poorly marginated micronodular opacities in a miliary pattern. Pathology specimens obtained by transbronchial biopsy revealed amorphous material obstructing the pulmonary microvasculature. Microvascular emboli secondary to precipitated crystals is a potential complication of total parenteral nutrition. An awareness of the factors that influence crystal solubility may prevent adverse interactions in patients who require parenteral nutrition.