RESUMO
Ankylosing Spondylitis (AS) presents with both musculoskeletal and cardiorespiratory pathophysiological manifestations. Inspiratory muscle training (IMT) may be a useful intervention to address deficits in respiratory and functional status. CASE DESCRIPTION: A 25-year-old male with AS initially sought treatment for low back and right hip pain, but 7 weeks of IMT was also provided due to abnormal respiratory performance. OUTCOMES: At baseline, the patient presented with a resting respiratory rate (RR) of 14.5 breaths/minute, tidal volume (TV) of 0.76 L, minute ventilation (VE) of 10.87 L/min, and end tidal CO2 (PetCO2) of 30.56 mmHg. Baseline exercise test results revealed a VO2max of 44 ml/kg/min and VE to CO2 output (VE/VCO2) slope of 30. Baseline MIP, SMIP, and MEP were 54 cm H2O, 507 PTU, and 87 cm H2O, respectively, and increased to 176 cm H2O, 807 PTU, and 151 cm H2O, respectively, after IMT. The VO2max increased to 51 ml/kg/min with decreases in the VE/VCO2 slope (29), resting RR (12 breaths/minute), resting TV (0.52 L), and resting VE (6.83 L/min) after IMT. Improvements during postural challenges were also observed. DISCUSSION: This case demonstrates the clinical utility of respiratory gas analysis and respiratory performance measures to identify functional deficits and manage a patient with AS. The improvements in respiratory performance at rest, during postural challenges, and during maximal exercise after a relatively short period of IMT highlights the role IMT may have to improve functional status in patients with AS. Further investigation of IMT in patients with AS is warranted.