Epidemiology of Respiration with Mandibular Movement in Advanced Cancer Patients: A Multicenter Prospective Cohort Study.

Respiration with mandibular movement (RMM) is one of the important clinical signs of impending death. However, there is very limited data on its natural course. This study was conducted in 23 inpatient palliative care units in Japan. It aimed to explore the natural course of RMM. Among a total of 1526 cancer patients included, 1065 patients (69.8%) had RMM. A total of 14.8% patients experienced respiratory arrest within 30 minutes from RMM onset, 14.3% within 30-60 minutes, 34.4% within 1-4 hours, 17.5% within 4-12 hours, 8.9% within 12-24 hours, and 10.4%> 24 hours. Mean oxygen saturation and percentage of patients with SpO ≥90% at RMM onset were found to be significantly higher in patients with longer durations from RMM onset to death ( < 0.001). RMM occurred in a majority (80%) of dying patients within 12 hours. A minority of the patients survived >24 hours.