A previously normal newborn infant in a community hospital nursery is noted to be cyanotic at 14 h of life. She is placed on a face mask with oxygen flowing at 10 LPM. She remains cyanotic, and her pulse oximetry reading does not change. An arterial blood gas shows her PaO2 to be 23 mmHg. Bilateral breath sounds are present, and she has no murmur. She is breathing deeply and quickly, but she is not retracting. You are concerned about congenital heart disease. While you are waiting for the transport team from the nearby children’s hospital, you should initiate which of the following?
a. Indomethacin infusion
b. Saline infusion
c. Adenosine infusion
d. Prostaglandin E1 infusion
e. Digoxin infusion
the answer is below…
The United States Medical Licensing Examination, or USMLE for short, is a three-part licensing examination that is required in order to receive a license to practice medicine within the United States.
The USMLE assesses a physician’s ability to apply knowledge, concepts, and principles, and to determine fundamental patient-centered skills that are important in health and disease and that constitute the basis of safe and effective patient care.Examination committees composed of medical educators and clinicians from across the United States and its territories prepare the examination materials each year.
This exam is designed by the Federation of State Medical Boards and the National Board of Medical Examiners to determine whether or not an individual understands and can apply the knowledge necessary to practice medicine safely and intelligently.
The USMLE is actually comprised of three different exams that are referred to as steps, which examine the individual’s knowledge of specific topics related to the field of medicine such as basic science, medical knowledge, medical skills, clinical science, and the application of all of these skills and areas of knowledge in the medical field.
All three steps of the USMLE include a series of computerized multiple-choice questions, but the format of the exam and the information covered in each multiple-choice section is different for each step of the USMLE. The USMLE Step II also has a clinical skills portion that examines an individual’s ability to work with real patients and the USMLE Step III has a computerized patient simulation portion in addition to the multiple-choice section of the exam. In order for an individual to receive a license to practice medicine, the individual must pass all three steps of the USMLE.
The correct answer is d; Prostaglandin E1 infusion.
The vignette describes an infant with a ductal-dependant cyanotic congenital heart lesion. In this example, the child had pulmonary atresia without a corresponding ventricular septal defect; another example would have been transposition of the great vessels without a septal defect to allow mixing of oxygenated and nonoxygenated blood. Cyanotic infants who do not improve their saturations with supplemental oxygen should be evaluated carefully for structural heart disease. The ductus arteriosis typically closes in the first few hours of life; thus, these children will develop their cyanosis in the same time frame.