Background: High-flow nasal cannula (HFNC) oxygen therapy is being increasingly used to prevent postextubation hypoxemic respiratory failure and reintubation. However, evidence to support the use of HFNC in chronic obstructive pulmonary disease (COPD) patients with hypercapnic respiratory failure after extubation is limited. This study was conducted to test if HFNC is non-inferior to non-invasive ventilation (NIV) in preventing post-extubation treatment failure in COPD patients previously intubated for hypercapnic respiratory failure. Methods: COPD patients with hypercapnic respiratory failure who were already receiving invasive ventilation were randomized to HFNC or NIV at extubation at two large tertiary academic teaching hospitals. The primary endpoint was treatment failure, defined as either resumption of invasive ventilation or switching to the other study treatment modality (NIV for patients in the NFNC group or vice versa). Results: Ninety-six patients were randomly assigned to the HFNC group or NIV group. After secondary exclusion, 44 patients in the HFNC group and 42 patients in the NIV group were included in the analysis. The treatment failure rate in the HFNC group was 22.7% and 28.6% in the NIV group-risk difference of − 5.8% (95% CI, − 23.8-12.4%, p = 0.535), which was significantly lower than the non-inferior margin of 9%. Analysis of the causes of treatment failure showed that treatment intolerance in the HFNC group was significantly lower than that in the NIV group, with a risk difference of − 50.0% (95% CI, − 74.6 to − 12.9%, p = 0.015). One hour after extubation, the mean respiratory rates of both groups were faster than their baseline levels before extubation (p < 0.050). Twenty-four hours after extubation, the respiratory rate of the HFNC group had returned to baseline, but the NIV group was still

Background High-flow nasal cannula (HFNC) oxygen therapy in acute hypoxic respiratory failure is becoming increasingly popular. However, evidence to support the use of HFNC in acute respiratory failure (ARF) with hypercapnia is limited. Methods Chronic obstructive pulmonary disease (COPD) patients with moderate hypercapnic ARF (arterial blood gas pH 7.25–7.35, PaCO 2 >50 mmHg) who received HFNC or non-invasive ventilation (NIV) in the intensive care uint from April 2016 to March 2018 were analyzed retrospectively. The endpoint was treatment failure, defined as either invasive ventilation, or a switch to the other study treatment (NIV for patients in the NFNC group, and vice-versa), and 28-day mortality. Results Eighty-two COPD patients (39 in the HFNC group and 43 in the NIV group) were enrolled in this study. The mean age was 71.8±8.2 and 54 patients (65.9%) were male. The treatment failed in 11 out of 39 patients with HFNC (28.2%) and in 17 of 43 patients with NIV (39.5%) ( P =0.268). No significant differences were found for 28-day mortality (15.4% in the HFNC group and 14% in the NIV group, P =0.824). During the first 24 hrs of treatment, the number of nursing airway care interventions in the HFNC group was significantly less than in the NIV group, while the duration of device application was significantly longer in the HFNC group (all P <0.05). Skin breakdown was significantly more common in the NIV group (20.9% vs 5.1%, P <0.05). Conclusion Among COPD patients with moderate hypercarbic ARF, the use of HFNC compared with NIV did not result in increased rates of treatment failure, while there were fewer nursing interventions and skin breakdown episodes reported in the HFNC group.

Painful peripheral neuropathy is a common complication of diabetes mellitus. The symptom of pain can become a major factor that decreases the quality of life of patients with diabetes, while effective treatment is lacking. In the present study, we aimed to investigate the changes of pain threshold in the early stage of diabetes in db/db mice, an animal model of type 2 diabetes mellitus, and the underlying molecular mechanisms. We found that (1) db/db mice (with a leptin receptor-null mutation and characterized by obesity and hyperglycemia) showed hypersensitivity to mechanical and thermal stimuli at the early stage of diabetes; (2) phosphorylated extracellular signalregulated kinase (pERK), but not total ERK in the spinal cord and dorsal root ganglia in db/db mice signifi cantly increased compared with wild-type mice. The increased pERK immunoreactivity occurred in both NeuN-expressing neurons and GFAPexpressing astrocytes, but not in Iba-1-expressing microglia; (3) both single and consecutive (for 5 days) intrathecal injections of U0126 (2 nmol per day), a selective MEK (an ERK kinase) inhibitor beginning at 8 weeks of age, attenuated the bilateral mechanical allodynia in the von-Frey test and heat hyperalgesia in Hargreave's test; and (4) db/db mice also displayed increased nocifensive behavior during the formalin

Painful diabetic neuropathy (PDN) is a diabetes mellitus complication. Unfortunately, the mechanisms underlying PDN are still poorly understood. Adenosine triphosphate (ATP)-gated P2X7 receptor (P2X7R) plays a pivotal role in non-diabetic neuropathic pain, but little is known about its effects on streptozotocin (STZ)-induced peripheral neuropathy. Here, we explored whether spinal cord P2X7R was correlated with the generation of mechanical allodynia (MA) in STZ-induced type 1 diabetic neuropathy in mice. MA was assessed by measuring paw withdrawal thresholds and western blotting. Immunohistochemistry was applied to analyze the protein expression levels and localization of P2X7R. STZ-induced mice expressed increased P2X7R in the dorsal horn of the lumbar spinal cord during MA. Mice injected intrathecally with a selective antagonist of P2X7R and P2X7R knockout (KO) mice both presented attenuated progression of MA. Double-immunofluorescent labeling demonstrated that P2X7R-positive cells were mostly co-expressed with Iba1 (a microglia marker). Our results suggest that P2X7R plays an important role in the development of MA and could be used as a cellular target for treating PDN.