Clinical presentation in patients with isolated bilateral Diaphragmatic Palsy.and MEP/MIP ratio as an aid to diagnosis

Background: Isolated bilateral diaphragmatic palsy (BDP) in absence of progressive neuromuscular disease is not easy to diagnose. There are limited data on clinical presentation and prognosis. We present retrospective cohort data from 2 large teaching hospitals from United Kingdom.. Results: A total of 56 patients (37 men) with mean age of 58.5 years. Method: can be diivded into 3 groups. Post-op (Heart or Lung transplant)or post-ICU admission (24), Acute hypercapnic respiratory failure 12 Out-patient Clinic with symptoms 12. 2 patients developed BDP following radiofrequency ablation for arrhythmia. mode of presentation was missing in 6 patients. Except post op patients, orthopnoea or inability to lie supine was seen in most patients. Breahtlessness, somnolence and sleep disturbanvce was also present in most patients who presented acutely or in lcinic. 10 patients (post op or post ICU) presented as 9difficult to wean9 from mechanical ventilation. Method: Mean Upright Vital Capacity (VC) was 1.7 L (48% predicted) and mean drop VC when patients were Supine was 42.5%. In a proportion of these patients we measured mouth inspiratory and expiratory pressure (MIP and MEP respectively ) as well as sniff nasal inspiratory pressure (SNIP). MEP was relatively preserved with mean value 108.5 cm H2O. mean MIP was 43 cm H2O and SNIP was 35.3 cm H2O. Ratio of MEP:MIP was 2.88 and MEP to SNIP was 3.22. Conclusion: In patients with BDP without progressive neuromuscular condition, inability to lie down was associated with > 25% Postural drop in VC. MEP/MIP and MEP/SNIP ratio of nrealy 3 was associated with postural drop of 25% in VC and can be a diagnostic tool.