Sigurd Aarrestad1, Magnus Qvarfort2, Anne Louise Kleiven3, Elin Tollefsen4, Ole Henning Skjønsberg5, Jean-Paul Janssens6. 1. Department of Pulmonary Medicine, Oslo University Hospital, Ullevål, Norway; Norwegian National Advisory Unit on Long Term Mechanical Ventilation, Haukeland University Hospital, Norway; University of Oslo, Oslo, Norway. Electronic address: UXSIRR@ous-hf.no. 2. Department of Pulmonary Medicine, Oslo University Hospital, Ullevål, Norway. Electronic address: UXQVMA@ous-hf.no. 3. Department of Pulmonary Medicine, Oslo University Hospital, Ullevål, Norway. Electronic address: ANKLEI@ous-hf.no. 4. Department of Thoracic Medicine, St. Olavs Hospital, Trondheim, Norway; Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, St. Olavs Hospital, Postboks 3250 Sluppen, 7006 Trondheim, Norway. Electronic address: elin.tollefsen@ntnu.no. 5. Department of Pulmonary Medicine, Oslo University Hospital, Ullevål, Norway; University of Oslo, Oslo, Norway. Electronic address: o.h.skjonsberg@medisin.uio.no. 6. Division of Pulmonary Diseases, Geneva University Hospitals, Switzerland, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland. Electronic address: Jean-Paul.Janssens@hcuge.ch.
Abstract
BACKGROUND: Non-invasive ventilation (NIV) is increasingly used in the treatment of patients with chronic hypercapnic respiratory failure (CRF). Residual sleep related respiratory events under NIV such as obstructive or central apnea/hypopnea (AH), or patient-ventilator asynchrony (PVA), may compromise treatment efficacy and/or comfort. AIMS OF STUDY: 1/to quantify the frequency and describe the types of both AH and PVA in a large group of stable patients with CRF during night-time NIV; 2/to analyze the influence of these events on overnight pulse oximetry and transcutaneous CO2 and 3/to assess interrater agreement in identifying and quantifying AH and PVA. METHODS: We quantified AH and PVA by performing sleep polygraphy in 67 patients during elective follow-up visits. Traces were scored by two trained physicians. RESULTS: Residual AH were frequent: 34% of the patients had an AH Index >5/hour, with obstructive hypopnea being the most frequent event. In addition, 21% of the patients had PVA >10% of total recording time. No correlation was found between respiratory events and overnight hypercapnia. The intraclass correlation coefficients for scoring AHI and time with PVA were 0.97 (0.94-0.98) and 0.85 (0.75-0.91) respectively. CONCLUSIONS: Residual respiratory events are common in patients treated with long term NIV for chronic hypercapnic respiratory failure and can be scored with a very high interobserver agreement. However, these events were not associated with persistent nocturnal hypercapnia; thus, their clinical relevance has yet to be clarified. CLINICALTRIALS.GOV REGISTRATION N°: NCT01845233.
BACKGROUND: Non-invasive ventilation (NIV) is increasingly used in the treatment of patients with chronic hypercapnic respiratory failure (CRF). Residual sleep related respiratory events under NIV such as obstructive or central apnea/hypopnea (AH), or patient-ventilator asynchrony (PVA), may compromise treatment efficacy and/or comfort. AIMS OF STUDY: 1/to quantify the frequency and describe the types of both AH and PVA in a large group of stable patients with CRF during night-time NIV; 2/to analyze the influence of these events on overnight pulse oximetry and transcutaneous CO2 and 3/to assess interrater agreement in identifying and quantifying AH and PVA. METHODS: We quantified AH and PVA by performing sleep polygraphy in 67 patients during elective follow-up visits. Traces were scored by two trained physicians. RESULTS: Residual AH were frequent: 34% of the patients had an AH Index >5/hour, with obstructive hypopnea being the most frequent event. In addition, 21% of the patients had PVA >10% of total recording time. No correlation was found between respiratory events and overnight hypercapnia. The intraclass correlation coefficients for scoring AHI and time with PVA were 0.97 (0.94-0.98) and 0.85 (0.75-0.91) respectively. CONCLUSIONS: Residual respiratory events are common in patients treated with long term NIV for chronic hypercapnic respiratory failure and can be scored with a very high interobserver agreement. However, these events were not associated with persistent nocturnal hypercapnia; thus, their clinical relevance has yet to be clarified. CLINICALTRIALS.GOV REGISTRATION N°: NCT01845233.