{
  "abstract": "Introduction Home non-invasive ventilation (NIV) is an established treatment for chronic hypercapnic respiratory failure, but physiological responses and adherence may differ between disease phenotypes. We compared three-month outcomes between chronic obstructive pulmonary disease (COPD) and obesity-related respiratory failure (ORRF) patients initiated on remotely monitored outpatient NIV.Methods We analysed prospectively collected data from all patients initiated on remotely monitored outpatient NIV at a UK tertiary centre (February 2023-January 2025). Data included baseline and first follow-up data, including gas exchange, COPD Assessment Test (CAT), Epworth Sleepiness Scale (ESS) and device usage. The primary endpoint was change in (Δ) PaCO 2 at first follow-up. Secondary endpoints included ΔPaO2, ΔHCO3 −, ESS and CAT scores at first follow-up and responder rate (defined as ΔPaCO2 ≥ 0.5 kPa). Acceptable adherence was pre-defined as ≥4 hours nightly use (30 day mean).Results Fifty-one patients were analysed, 37 with COPD (72.5%) and 14 with ORRF (27.5%): mean age 63 ±13 years, 26 (51%) were female. Adherence data were available for 49 (96%) patients, with median follow-up of 3.7 months. Adherence was similar between groups, COPD patients 4.45h (IQR 1.51–7.80) versus ORRF patients 4.34h (IQR 2.30–5.47), p=0.56. Acceptable adherence was achieved by 20/37 (54%) of COPD patients and 8/14 (57%) of ORRF patients.Mean PaCO2 decreased in all groups with the largest reduction in adherent ORRF patients (–1.21 kPa [95% CI: -2.00, -0.42]) (table 1). Adherent COPD patients experienced an improved PaO2 (+1.04 kPa [95% CI: 0.40, 1.49]) and reduced bicarbonate (–3.15 mmol L− 1 [95% CI: -3.92, -1.14]). Responder rate was 7/14 (50%) in ORRF and 15/37 (40.5%) of COPD patients. Median CAT scores improved in COPD patients (-8.5 [95% CI: -15.00, -1.00]).Abstract S78 Table 1Changes in physiological parameters and symptom/quality of life scores from baseline to first follow-up COPD all (n=37) COPD Adherence ≥ 4 h (n=20) COPD Adherence < 4 h (n=15) ORRF all (n=14) ORRF Adherence ≥ 4 h (n=8) ORRF Adherence < 4 h (n=6) ΔPaCO2 (kPa) –0.20 (± 1.41) [6.92→6.72] –0.47 (± 1.30) [6.89→6.43] –0.10 (± 1.00) [6.88→6.77] –0.78* (± 0.91) [6.71→5.93] –1.21* (± 0.95) [6.89→5.68] –0.21 (± 0.43) [6.48→6.27] ΔPaO2 (kPa) +0.54 (± 2.65) [8.26→8.80] +1.04* (± 0.94) [8.05→9.09] –0.20 (± 3.98) [8.68→8.48] +0.88 (± 2.65) [8.72→9.60] +1.76 (± 4.67) [8.77→10.53] +0.22 (± 0.36) [8.64→8.86] ΔHCO3 − (mmol L− 1) –1.59* (± 8.56) [31.13→29.54] –3.15* (± 2.30) [31.03→27.88] +2.28 (± 8.09) [30.84→33.12] –1.14 (±12.46) [30.46→29.3] –1.57 (± -) [30.20→28.63] –0.97 (± 0.10) [30.85→29.88] ΔESS –1.0 (-4 to 0) [7.0→6.0] –3.0 (-5 to 0) [9.0→6.0] –1.0 (-4 to 0) [7.0→6.0] –3.0 (-7 to 0) [8.5→5.5] –2.0 (-9 to 2) [7.5→5.5] –2.5 (-5.5 to -0.5) [8.5→6.0] ΔCAT –8.5* (-12 to 3) [22.5→14.0] –9.0* (-12 to -4 ) [23.0→14.0] –4.0 (-15 to 3) [18.0→14.0] — — — PaCO2 reduction ≥ 0.5 (kPa) N (%) 15 (41%) 9 (45%) 5 (33%) 7 (50%) 6 (75%) 1 (25%) Data are presented as mean change (SD) [baseline mean to follow-up mean] for physiological parameters (ΔPaCO2, ΔPaO2, ΔHCO3 −) and median change (IQR) [baseline median to follow-up median] for symptom/quality of life scores (ΔESS, ΔCAT). *p < 0.05.Conclusions With similar usage of NIV, ORRF patients demonstrated a better response to normalise hypercapnic respiratory failure, while COPD patients had greater improvement in oxygenation and reduction in their bicarbonate levels. There was an effect of adherence on therapeutic efficacy. However, these findings underline the effectiveness of outpatient set-up of home NIV in improving respiratory failure and symptoms in patients with COPD and ORRF.",
  "authors": [
    {
      "affiliations": [
        "GKT School of Medicine, Kings College London, London, UK"
      ],
      "name": "HY Yap"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "K Abernethy"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "N Shah"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "KA Arif"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "S Bokhari"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "R D’Cruz"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "N Hart"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "G Kaltsakas"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "M Ramsay"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "S Srivastava"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "J Steier"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "P Murphy"
    },
    {
      "affiliations": [
        "Lane Fox Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK"
      ],
      "name": "ES Suh"
    }
  ],
  "title": "S78 Exploring phenotype-specific response to home non-invasive ventilation in chronic hypercapnic respiratory failure",
  "uid": "1be5cae0-72ee-57cc-b489-2f7f29189200"
}