Palliative care in critically ill COVID-19 patients: the early New York City experience.

OBJECTIVES: The COVID-19 pandemic in the USA has been accompanied by high rates of mortality and an unprecedented need for palliative care delivery. Little is known about the use of palliative care services in intensive care unit (ICU) settings during the COVID-19 pandemic. METHODS: This is a retrospective cohort study of critically ill COVID-19 patients requiring ICU admission, between 7 March and 14 April 2020 to two academic teaching hospitals in New York City. Palliative care consultation included a one-time telemedicine consultation or continued telemedicine consultation and follow-up with multidisciplinary team involvement. Patient information was collected from the electronic health record and analyses were conducted with Stata V.15.1 (StataCorp) statistical software. RESULTS: A total of 151 critically ill patients with COVID-19 pneumonia requiring ICU admission were identified, of whom 59 (39.07%) received an inpatient palliative care consultation. More than half of patients died (n=85/151, 56.29%), with 57.65% (n=49/85) of these patients receiving palliative care services during their hospitalisation. Patients who received palliative care consultation were more likely to be older, sicker and receive mechanical ventilation than their counterparts. Patients who died and did not receive palliative care were younger and required non-invasive ventilation support. CONCLUSION: There is a lack of utilisation of palliative care in COVID-19 patients admitted to the ICU. Further research into predictors of poor outcomes in critically ill COVID-19 patients may help identify patients that would benefit from early palliative care involvement going forward.

Slow-frequency electroencephalography activity during wake and sleep in obesity hypoventilation syndrome.

STUDY OBJECTIVE: Neurophysiological activity during wake and sleep states in obesity hypoventilation (OHS) and its relationship with neurocognitive function is not well understood. This study compared OHS with equally obese obstructive sleep apnea (OSA) patients, with similar apnea-hypopnea indices. METHODS: Resting wake and overnight sleep electroencephalography (EEG) recordings, neurocognitive tests, and sleepiness, depression and anxiety scores were assessed before and after 3 months of positive airway pressure (PAP) therapy in 15 OHS and 36 OSA patients. RESULTS: Pretreatment, greater slow frequency EEG activity during wake and sleep states (increased delta-alpha ratio during sleep, and theta power during awake) was observed in the OHS group compared to the OSA group. EEG slowing was correlated with poorer performance on the psychomotor vigilance task (slowest 10% of reciprocal reaction times, psychomotor vigilance test [PVT SRRT], primary outcome), and worse sleep-related hypoxemia measures in OHS. There was no between-group significant difference in PVT performance at pre or post-treatment. Similarly, despite both groups demonstrating improved sleepiness, anxiety and depression scores with PAP therapy, there were no differences in treatment response between the OSA and OHS groups. CONCLUSION: Patients with OHS have greater slow frequency EEG activity during sleep and wake than equally obese patients with OSA. Greater EEG slowing was associated with worse vigilance and lower oxygenation during sleep. CLINICAL TRIAL: This trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12615000122550).

Intra-individual stability of NREM sleep quantitative EEG measures in obstructive sleep apnea.

Electroencephalography is collected routinely during clinical polysomnography, but is often utilised to simply determine sleep time to calculate apnea-hypopnea indices. Quantitative analysis of these data (quantitative electroencephalogram) may provide trait-like information to predict patient vulnerability to sleepiness. Measurements of trait-like characteristics need to have high test-retest reliability. We aimed to investigate the intra-individual stability of slow-wave (delta power) and spindle frequency (sigma power) activity during non-rapid eye movement sleep in patients with obstructive sleep apnea. We recorded sleep electroencephalograms during two overnight polysomnographic recordings in 61 patients with obstructive sleep apnea (median days between studies 47, inter-quartile range 53). Electroencephalograms recorded at C3-M2 derivation were quantitatively analysed using power spectral analysis following artefact removal. Relative delta (0.5-4.5 Hz) and sigma (12-15 Hz) power during non-rapid eye movement sleep were calculated. Intra-class correlation coefficients and Bland-Altman plots were used to assess agreement between nights. Intra-class correlation coefficients demonstrated good-to-excellent agreement in the delta and sigma frequencies between nights (intra-class correlation coefficients: 0.84, 0.89, respectively). Bland-Altman analysis of delta power showed a mean difference close to zero (-0.4, 95% limits of agreement -9.4, 8.7) and no heteroscedasticity with increasing power. Sigma power demonstrated heteroscedasticity, with reduced stability as sigma power increased. The mean difference of sigma power between nights was close to zero (0.1, 95% limits -1.6, 1.8). We have demonstrated the stability of slow-wave and spindle frequency electroencephalograms during non-rapid eye movement sleep within patients with obstructive sleep apnea. The electroencephalogram profile during non-rapid eye movement sleep may be a useful biomarker for predicting vulnerability to daytime impairment in obstructive sleep apnea and responsiveness to treatment.

Cough Augmentation Techniques in the Critically Ill: A Canadian National Survey.

BACKGROUND: Critically ill mechanically ventilated patients experience impaired airway clearance due to ineffective cough and impaired secretion mobilization. Cough augmentation techniques, including mechanical insufflation-exsufflation (MI-E), manually assisted cough, and lung volume recruitment, improve cough efficiency. Our objective was to describe use, indications, contraindications, interfaces, settings, complications, and barriers to use across Canada. METHODS: An e-mail survey was sent to nominated local survey champions in eligible Canadian units (ICUs, weaning centers, and intermediate care units) with 4 telephone/e-mail reminders. RESULTS: The survey response rate was 157 of 238 (66%); 78 of 157 units (50%) used cough augmentation, with 50 (64%) using MI-E, 53 (68%) using manually assisted cough, and 62 (79%) using lung volume recruitment. Secretion clearance was the most common indication (MI-E, 92%; manually assisted cough, 88%; lung volume recruitment, 76%), although the most common units (44%) used it <50% of the time. Use during weaning from invasive (MI-E, 21%; manually assisted cough, 39%; lung volume recruitment, 3%) and noninvasive ventilation (MI-E, 21%; manually assisted cough, 33%; lung volume recruitment, 21%) was infrequent. The most common diagnoses were neuromuscular disease (97%) and spinal cord injury (83%). Pneumothorax was the most frequently identified absolute contraindication for MI-E (93%) and lung volume recruitment (83%); rib fracture was most frequently identified for manually assisted cough (69%). MI-E mean inspiratory pressure was 31 cm H2O, and expiratory pressure was -32 cm H2O. Mucus plugging requiring tracheostomy inner change was the most frequent complication for MI-E (23%), chest pain for manually assisted cough (36%), and hypotension for lung volume recruitment (17%). The most commonly cited barriers were lack of expertise (70%), knowledge (65%), and resources (52%). CONCLUSIONS: We found moderate adoption of cough augmentation techniques, particularly for secretion management. Lack of expertise and knowledge are potentially modifiable barriers addressed with educational interventions.

Recent Advances in Nanostructured Thermoelectric Half-Heusler Compounds.

Half-Heusler (HH) alloys have attracted considerable interest as promising thermoelectric (TE) materials in the temperature range around 700 K and above, which is close to the temperature range of most industrial waste heat sources. The past few years have seen nanostructuing play an important role in significantly enhancing the TE performance of several HH alloys. In this article, we briefly review the recent progress and advances in these HH nanocomposites. We begin by presenting the structure of HH alloys and the different strategies that have been utilized for improving the TE properties of HH alloys. Next, we review the details of HH nanocomposites as obtained by different techniques. Finally, the review closes by highlighting several promising strategies for further research directions in these very promising TE materials.