Opioid painkillers are a promising treatment for chronic breathlessness, but are associated with potentially fatal side effects. In the treatment of breathlessness, their mechanisms of action are unclear. A better understanding might help to identify safer alternatives. Learned associations between previously neutral stimuli (e.g. stairs) and repeated breathlessness induce an anticipatory threat response that may worsen breathlessness, contributing to the downward spiral of decline seen in clinical populations. As opioids are known to influence associative learning, we hypothesized that they may interfere with the brain processes underlying a conditioned anticipatory response to breathlessness in relevant brain areas, including the amygdala and the hippocampus.Healthy volunteers viewed visual cues (neutral stimuli) immediately before induction of experimental breathlessness with inspiratory resistive loading. Thus, an association was formed between the cue and breathlessness. Subsequently, this paradigm was repeated in two identical neuroimaging sessions with intravenous infusions of either low-dose remifentanil (0.7 ng/ml target-controlled infusion) or saline (randomised).During saline infusion, breathlessness anticipation activated the right anterior insula and the adjacent operculum. Breathlessness was associated with activity in a network including the insula, operculum, dorsolateral prefrontal cortex, anterior cingulate cortex and the primary sensory and motor cortices.Remifentanil reduced breathlessness unpleasantness but not breathlessness intensity. Remifentanil depressed anticipatory activity in the amygdala and the hippocampus that correlated with reductions in breathlessness unpleasantness. During breathlessness, remifentanil decreased activity in the anterior insula, anterior cingulate cortex and sensory motor cortices. Remifentanil-induced reduction in breathlessness unpleasantness was associated with increased activity in the rostral anterior cingulate cortex and nucleus accumbens, components of the endogenous opioid system known to decrease the perception of aversive stimuli.These findings suggest that in addition to effects on brainstem respiratory control, opioids palliate breathlessness through an interplay of altered associative learning mechanisms. These mechanisms provide potential targets for novel ways to develop and assess treatments for chronic breathlessness.

Background: The optimal method for diagnosing ventilator-associated pneumonia (VAP) is controversial and its effect on reported incidence uncertain. This study aimed to model the impact of using either endotracheal aspirate or bronchoalveolar lavage on the reported incidence of pneumonia and then to test effects suggested from theoretical modelling in clinical practice. Methods: A three-part single-centre study was undertaken. First, diagnostic performance of aspirate and lavage were compared using paired samples from 53 patients with suspected VAP. Secondly, infection surveillance data were used to model the potential effect on pneumonia incidence and antibiotic use of using exclusively aspirate or lavage to investigate suspected pneumonia (643 patients; 110 clinically suspected pneumonia episodes). Thirdly, a practice change initiative was undertaken to increase lavage use; pneumonia incidence and antibiotic use were compared for the 12 months before and after the change. Results: Aspirate overdiagnosed VAP compared with lavage (89% vs 21% of clinically suspected cases, p,0.0001). Modelling suggested that changing from exclusive aspirate to lavage diagnosis would decrease reported pneumonia incidence by 76% (95% CI 67% to 87%) and antibiotic use by 30% (95% CI 20% to 42%). After the practice change initiative, lavage use increased from 37% to 58%. Although clinically suspected pneumonia incidence was unchanged, microbiologically confirmed VAP decreased from 18 to 9 cases per 1000 ventilator days (p = 0.001; relative risk reduction 0.61 (95% CI 0.46 to 0.82)), and mean antibiotic use fell from 9.1 to 7.2 antibiotic days (21% decrease, p = 0.08). Conclusions: Diagnostic technique impacts significantly on reported VAP incidence and potentially on antibiotic use.

Literature on New-Onset Refractory Status Epilepticus (NORSE) is scarce and management is guided mainly by retrospective reports, short case series or expert opinions. We aimed to add to the pool of the available data by retrospectively reviewing seven cases of NORSE cases admitted to our hospital over the last five years between January 2014 and March 2019. Methods: Fully anonymised data from medical charts, EEG reports, imaging reports, laboratory test results, types of antiepileptic medications, intravenous anaesthetic therapy, and immune therapies received was collected, along with response to treatment, length of hospital stay and outcome at discharge. Results: The mean age was 43.5 ± 23.8 years (range 18-75) and three patients were females. Prodromal symptoms consisted mainly of fever (4/7), headache (4/7) and self terminating seizures (7/7), before presenting with status epilepticus. Initial imaging findings were abnormal in 3/7 and CSF analysis in 3/7. All patients underwent intermittent EEG recordings, mainly for titration or tapering of the anaesthetic agents, with the initial goal of achieving burst suppression and cessation of electrographic seizures. Our index case spent the longest time in therapeutic burst suppression (102 days) and remained on thiopentone for 214 days. The mean duration of NICU stay was 88 ± 85.4 days (range 4-225 days) while the mean duration of hospital stay was 113.8 ± 111.2 days (range 17-292). Conclusions: The management of patients with NORSE remains challenging, often requiring multiple intravenous anaesthetic treatments, leading to complicated and prolonged hospital and intensive care unit stays but good outcome remains possible.

Capillary blood gas measurements provide an accurate assessment of PCO(2), H(+) and HCO(3)(-) and can be used to reliably measure the ventilatory status of patients. Combined with continuous pulse oximetry they can be used as an alternative to arterial blood gas measurements in patients with acute exacerbations of COPD.