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Abstract Introduction We were able to treat a patient with acute exacerbation of chronic obstructive pulmonary disease who also suffered from sleep-disordered breathing by using the average volume-assured pressure support mode of a Respironics V60 Ventilator (Philips Respironics: United States). This allows a target tidal volume to be set based on automatic changes in inspiratory positive airway pressure. This removed the need to change the noninvasive positive pressure ventilation settings during the day and during sleep. The Respironics V60 Ventilator, in the average volume-assured pressure support mode, was attached to our patient and improved and stabilized his sleep-related hypoventilation by automatically adjusting force to within an acceptable range. Case presentation Our patient was a 74-year-old Japanese man who was hospitalized for treatment due to worsening of dyspnea and hypoxemia. He was diagnosed with acute exacerbation of chronic obstructive pulmonary disease and full-time biphasic positive airway pressure support ventilation was initiated. Our patient was temporarily provided with portable noninvasive positive pressure ventilation at night-time following an improvement in his condition, but his chronic obstructive pulmonary disease again worsened due to the recurrence of a respiratory infection. During the initial exacerbation, his tidal volume was significantly lower during sleep (378.9 ± 72.9mL) than while awake (446.5 ± 63.3mL). A ventilator that allows ventilation to be maintained by automatically adjusting the inspiratory force to within an acceptable range was attached in average volume-assured pressure support mode, improving his sleep-related hypoventilation, which is often associated with the use of the Respironics V60 Ventilator. Polysomnography performed while our patient was on noninvasive positive pressure ventilation revealed obstructive sleep apnea syndrome (apnea-hypopnea index = 14), suggesting that his chronic obstructive pulmonary disease was complicated by obstructive sleep apnea syndrome. Conclusion In cases such as this, in which patients with severe acute respiratory failure requiring full-time noninvasive positive pressure ventilation therapy also show sleep-disordered breathing, different ventilator settings must be used for waking and sleeping. On such occasions, the Respironics V60 Ventilator, which is equipped with an average volume-assured pressure support mode, may be useful in improving gas exchange and may achieve good patient compliance, because that mode allows ventilation to be maintained by automatically adjusting the inspiratory force to within an acceptable range whenever ventilation falls below target levels.

Abstract Background Recently, hypothalamus-pituitary-adrenal (HPA) axis function assessed with the combined dexamethasone (DEX)/corticotropin releasing hormone (CRH) test has been shown to be associated with response to antidepressant treatment. A polymorphism (rs16944) in the interleukin-1beta (IL-1β) gene has also been reported to be associated with the medication response in depression. These findings prompted us to examine the possible association between IL-1β gene polymorphisms and HPA axis function assessed with the DEX/CRH test. Methods DEX/CRH test was performed in 179 healthy volunteers (45 males: mean age 40.5 ± 15.8 years; 134 females: mean age 47.1 ± 13.2 years). Five tagging single nucleotide polymorphisms (SNPs) of IL-1β gene (rs2853550, rs1143634, rs1143633, rs1143630, rs16944) were selected at an r2 threshold of 0.80 with a minor allele frequency > 0.1. Genotyping was performed by the TaqMan allelic discrimination assay. A two-way factorial analysis of variance (ANOVA) was performed with the DEX/CRH test results as the dependent variable and genotype and gender as independent variables. To account for multiple testing, P values < 0.01 were considered statistically significant for associations between the genotypes and the cortisol levels. Results The cortisol levels after DEX administration (DST-Cortisol) showed significant associations with the genotypes of rs16944 (P = 0.00049) and rs1143633 (P = 0.0060), with no significant gender effect or genotype × gender interaction. On the other hand, cortisol levels after CRH administration (DEX/CRH-Cortisol) were affected by gender but were not significantly influenced by the genotype of the examined SNPs, with no significant genotype × gender interaction. Conclusions Our results suggest that genetic variations in the IL-1β gene contribute to the HPA axis alteration assessed by DST-Cortisol in healthy subjects. On the other hand, no significant associations of the IL-1β gene polymorphisms with the DEX/CRH-Cortisol were observed. Confirmation of our findings in futures studies may add new insight into the communication between the immune system and the HPA axis.