P3.272: Extreme Tachypnea and Congenital Diaphragm Paresis: An Uncommon Diagnosis Requiring Navigation of Care in a Resource-Limited Military Treatment Facility

Introduction: Tachypnea in early infancy is often associated with a high risk of morbidity and mortality, from congenital cardiac anomalies, respiratory infections or metabolic disturbances. Less common etiologies can be challenging to identify with limited resources. We describe a 2-month-old healthy infant presenting with extreme tachypnea to a remote military treatment facility (MTF) with limited subspecialty pediatric resources/advanced imaging.

Case Description: A 2-month male presented for his well visit with no concerns. His respiratory rate was found to be in the 80s-90s with normal oxygenation. Physical examination revealed tachypnea with no evidence of increased work of breathing. Breath sounds were clear and symmetric throughout lung fields. There was a new, soft II/VI murmur at the lower left sternal border, normal femoral pulses, no hepatosplenomegaly and normal capillary refill. Chest radiograph demonstrated mild asymmetry of the hemidiaphragm, questionable increase in perihilar markings and subtle enhancement of the cardiothymic silhouette. Growth, birth, feeding, and developmental history were unremarkable. Parents denied atypical sleep, feeding or fussiness; mother noted that his breathing was possibly “faster” the last few days. Pediatric Cardiology was consulted via phone who agreed that the infant could be evaluated during their upcoming trip the following week. 24-hour outpatient follow up revealed increased tachypnea to the 100s, slight fussiness, and venous blood gas indicated a respiratory alkalosis prompting admission to the local hospital. After observation, a normal echocardiogram, and normal laboratory evaluation, he was discharged home. He continued to have extreme tachypnea during follow up, so outpatient Chest CT and diaphragm ultrasound were ordered, though quite difficult to coordinate. Chest CT showed eventration of right diaphragm containing a portion of the liver which was not communicated to the family or the primary medical team. On follow up, the infant was reported to have decreased feeding and increased fussiness, with continued tachypnea of >110 breaths per minute. The infant was medically transported to a tertiary MTF for multidisciplinary evaluation; moderate liver eventration and right hemidiaphragm paresis were confirmed. Pediatric surgery recommended conservative management in lieu of plication. Pediatric Pulmonology coordinated itinerant follow up and developed a plan if tachypnea progressed. The family was supported in their efforts to seek compassionate reassignment to a location with appropriate specialists and resources.

Discussion: Extreme tachypnea in an infant requires urgent evaluation to rule out life-threatening etiologies. Hemidiaphragm paresis can be congenital or result from phrenic nerve damage (i.e. from birth injury or surgery). For patients with unique presentations in remote settings, fragmented care poses risks such as delayed diagnosis, inadequate information sharing between institutions, and worse outcomes.

Conclusion: This case highlights the diagnostic and management challenges of unique diagnoses in remote settings. Military pediatricians must be familiar with local limitations and extended resources when complex or unique pathology arises.