C43-50 A Breath of Uncertainty: An Unusual Case of Diaphragmatic Paralysis in a Young Adult

Abstract Diaphragmatic paralysis occurs when the diaphragm loses the ability to contract, generally due to nerve or muscle damage. This is commonly iatrogenic but can also be caused by chest wall or cervical spine trauma, or an inflammatory process. Unilateral diaphragmatic paralysis is uncommon with literature suggesting an incidence of 1-20% and is commonly misdiagnosed as patients often present asymptomatically or with vague symptoms such as dyspnea on exertion. Here we present the case of a healthy male with the delayed diagnosis of right hemi-diaphragm paralysis. This is the case of a 34-year-old healthy male, who presented with shortness of breath and right shoulder pain. Initial vitals were significant for tachycardia and hypoxia (80%) on room air requiring 4 liters nasal cannula to maintain oxygen saturation above 90%. Chest x-ray was negative for acute cardiopulmonary process and CTA showed no pulmonary embolism. Right shoulder x-ray was negative and he was started on pain medications for a presumed strained muscle. After several days of hospitalization and inability to wean patient’s oxygen, a repeat chest x-ray was performed, which showed the right hemidiaphragm was higher than the left. With consideration of this finding in combination with hypoxia and right shoulder pain, and in an attempt to exhaust all further differentials, the patient underwent sniff testing, which showed right hemidiaphragm paralysis, concerning for a phrenic nerve injury. MRI of cervical spine showed no abnormalities. He was discharged on 4L oxygen with a pulmonary follow up. Acute hypoxia is a common presentation, however, it is uncommon in the younger population without preexisting lung disease, risk factors such as tobacco use, or recent illness. This case illustrates the diagnostic challenge of diaphragmatic paralysis, which can present with vague symptoms and oftentimes be overlooked on initial imaging. It is, therefore, important to broaden the initial differential for hypoxia in younger populations with no immediate obvious cause. Imaging is crucial for diagnosing unilateral diaphragmatic paralysis, and there should be a low threshold for further imaging and workup. Early diagnosis and identification of the underlying cause are crucial for early targeted treatment and improving outcomes. This abstract is funded by: None