Case Presentation: A 64 year-old male with a history of childhood polio leading to severe kyphoscoliosis presented to our hospital with four months of progressively worsening shortness of breath and was found to be in acute hypoxic and hypercapneic respiratory failure requiring noninvasive positive pressure ventilation (NPPV). On exam, he was altered and not responding to verbal cues. In addition, his cardiothoracic exam demonstrated severe kyphoscoliosis with his spinal column protruding left and posteriorly (Figure 1). Cardiac auscultation was benign. COVID and Influenza testing were negative. Chest x-ray was significant for severe thoracic deformity due to rib and spinal abnormalities. He was transferred to the medical intensive care unit after attempts to wean his oxygen requirements were unsuccessful.He was initially placed on ceftriaxone and azithromycin to treat possible community acquired pneumonia. Transthoracic echocardiogram showed moderate right ventricular dilatation, mildly reduced right ventricular global systolic function, moderate tricuspid regurgitation, and elevated right ventricular (RV) systolic pressure of 80 mmHg. Computed tomography of the chest was negative for pulmonary embolism but confirmed RV enlargement and dilated pulmonary arteries (Figure 2). Suspicion quickly increased for pulmonary hypertension (PH) and a diagnosis of (World Health Organization (WHO) group III PH as the cause of his respiratory failure. He was eventually able to be weaned to two liters of nasal canula with nocturnal NPPV. The presumed final diagnosis was acute on chronic respiratory failure due to WHO group III PH caused by restrictive chest wall deformity secondary to his severe scoliosis resulting from his childhood polio infection.

Discussion: Post Polio Syndrome is a condition that can emerge many years after initial infection and is characterized by progressive weakness of the infected neuromuscular structures leading to many sequelae, including scoliosis. The exact cause of this phenomena is not known but one theory is that surviving neurons from the initial infection create new dendritic branches to compensate for other neuron cell death. These over-extended neurons eventually weaken, thus weakening muscle function. This patient’s history of childhood polio infection likely led to weakening of his paraspinal muscles resulting in severe scoliosis causing restrictive lung disease. This phenomenon is uncommon in itself but even more uncommon is the ensuing PH.

Conclusions: Our patient presented with acute hypoxic and hypercapnic respiratory failure associated with severe scoliosis. It is important for clinicians to remember that musculoskeletal abnormalities can lead to restrictive lung disease which, if severe, can lead to PH. Few reports have been published on the treatment of PH related to kyphoscoliosis related alveolar hypoventilation and similar cases have suggested and demonstrated efficacy of vasoactive medications (inhaled prostanoids, tadalafil, nifedipine) in addition to initial diuretics for improvement of symptoms and pulmonary artery pressure. Patients with this presentation should be screened for PH via transthoracic echocardiogram or other modality so that appropriate care may be administered early.

IMAGE 1: Figure 1: Severe kyphoscoliosis due to childhood Polio infection

IMAGE 2: Figure 2: CT image demonstrating severe kyphoscoliosis with moderate cardiomegaly, dilated main pulmonary arteries, and asymmetric enlargement of the right atrium and ventricle