Risk factors for respiratory depression in Opioid Use Disorder

Abstract

<b>Background:</b> Opioid-related deaths are increasing globally and are usually caused by respiratory failure. <b>Aims &amp; Objectives:</b> To investigate risk factors for respiratory depression (RD) in Opioid Use Disorder (OUD) through study of the relationship between RD and drug use characteristics. <b>Methods:</b> Four groups were compared (Table 1): OUD with comorbid COPD (OUD-COPD, n=13); OUD without COPD (OUD, n=7); opioid-naïve COPD patients (COPD, n=13); and healthy controls (HC, n=7). SpO₂%, end-tidal CO₂ (ETCO₂), transcutaneous CO₂ (TcCO₂), respiratory airflow and neural respiratory drive index (NRDI) derived from 2^nd intercostal space parasternal muscle electromyography were recorded continuously during resting tidal breathing. RD was defined as any of: ETCO₂ per breath &gt;6.6kPa, TcCO₂ &gt;6kPa, apnoea or SpO₂%&lt;90% for &gt;10s. <b>Results:</b> RD indices were observed in all OUD-COPD and OUD participants, but in only 2/7 HC and 2/13 COPD patients. Results of bivariate correlation analysis are shown in Table 2. <b>Conclusions:</b> Our data suggest that RD is common in OUD and is influenced by opioid agonist treatment dose and drug use duration. Capnography and NRDI are potentially useful to the study of overdose risk.