Introduction: Patients with chronic respiratory disease and oxyhemoglobin desaturation (SpO2) on exertion prefer portable oxygen concentrator (POC) despite not achieving adequate SpO2 correction (1). One study showed that 20% of patients had a lower SpO2 with POC than with portable liquid oxygen (PLO) (2).

Objective: To evaluate how many patients with desaturation on exertion do not adequately correct SpO2 with POC and require a change to PLO.

 Method: Patients with criteria for portable oxygen in our service are retrospectively analyzed. We included patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) with mean SpO2? 88% in the 6-minute walking test (6MWT).

 Results: 211 patients were analyzed, 140 COPD patients and 71 ILD patients.40 COPD (28.6%) and 32 ILD (45.1%) patients showed inadequate SpO2 correction with maximum pulses/min with POC. 6MWT with OLP was performed in 54 of those patients. In 18 patients (10 COPD and 8 ILD)  was performed directly with POL for intense oxygen desaturation and in 36 patients (17 COPD and 19 ILD) after finding inadequate correction with POC. 22 patients covered adequately with PLO, but 32 failed despite a maximum flow of 6L/min.

The patients with COPD walked an average of 34.6 meters more with the POL than with the POC (p=0.017). Patients with ILD walked an average of 14.7 meters more with the POL than with the POC, but without a statistically significant difference.

Conclusions: There is a high percentage of patients who fail to correct SpO2 with portable concentrador with maximum pulse flow.This should alert us.

(1)   Marti S. et al Respiratory Care.  2013; 58: 1606

(2) Gloeckl et al Repiratory Medicine 2019 2019; 156:26