Apnoeic and obstructive nonapnoeic sleep respiratory events.

Obstructive nonapnoeic event (ONE) scoring is shrouded in confusion. This is important in patients with mild disease, in whom precision is crucial. The aims of the present study were: 1) to identify ONEs using oesophageal pressure (OP) (OP-ONEs) and a noninvasive (NI) method (NI-ONEs); 2) to compare both methods of scoring; and 3) to determine the contribution of ONE definitions to clinical findings. Patients with suspected sleep apnoeas (respiratory disturbance index <or=10) during a first polysomnography were subjected to a second with an OP measurement. OP-ONEs and NI-ONEs were defined as an increase in OP or discernible reduction in the amplitude of thoracoabdominal bands with both desaturation and/or arousal. Bland-Altman analysis established agreement. Comparisons were made between OP-ONEs, NI-ONEs and clinical findings. In our sample (n = 90), the addition of an arousal to the NI-ONEs or OP-ONEs with only desaturation increased the number of NI-ONEs by 329 and 362%, respectively. NI-ONEs with arousal and/or desaturation detected 91% of OP-ONEs. The association with sleepiness depended on the incorporation of arousal into the definition of ONEs. In patients with mild disease, the addition of an arousal to ONEs, with only desaturation, markedly increased respiratory disturbance index, with probable therapeutic implications. Scoring respiratory events as apnoea and ONEs is easier and sufficiently accurate.