Pulmonary haemodynamics and gasometric parameters associated with exercise induced oxygen desaturation in idiopathic pulmonary fibrosis

Abstract

Background: Patients with idiopathic pulmonary fibrosis (IPF) usually presented with exercise induced oxygen desaturation (EID). We hypothesize that pulmonary function tests (PFTs), pulmonary haemodynamics, and gasometric parameters may contribute to EID. Objective: Randomized, double blind, prospective study conducted to evaluate different parameters that may contribute to EID in IPF. Patients and methods: Thirty-five patients with stable IPF were enrolled in this study. Resting PFTs, arterial blood gases, echocardiography, and incremental cardiopulmonary exercise testing (CPET) were done for all patients. Desaturated patients (DS) were those with reduced oxygen saturation ⩾4% in comparison to resting value and post exercise SaO2 ⩽88%, the remaining patients were considered non desaturated (NDS) group. Results: Nearly half of patients had EID (17/35); it was observed in those who had lower FVC%, FEV1%, DLCO%, Resting PaO2, Resting PaCO2, higher mPAP with statistically significant difference between DS & NDS. DLCO ⩽25 had the highest specificity (100%), and mPAP ⩾25 had the highest sensitivity (88.9%) among functional and heamogasometric parameters in detection of EID. Conclusion: Exercise induced oxygen desaturation in IPF can be predicted from PFTs and haemogasometric parameters.

Keywords

• Idiopathic pulmonary fibrosis
• Survival
• Desaturation
• Predictors
• Exercise testing