Penn State equation versus indirect calorimetry for nutritional assessment in patients with traumatic brain injury.

BACKGROUND: Nutritional assessment can be challenging in patients with traumatic brain injury (TBI), and indirect calorimetry may be a more suitable method than predictive equations. We compared the Penn State equation versus the gold standard of indirect calorimetry for the nutritional assessment of patients with TBI, and quantified the difference between nutritional requirements and actual patient intake. METHODS: This single-centre, prospective cohort study included patients with moderate (Glasgow Coma Scale score 9-12) and severe (Glasgow Coma Scale score 3-8) TBI admitted to the Montreal General Hospital intensive care unit (ICU) between June 2018 and March 2019. Penn State equation estimates and indirect calorimetry measurements were collected, and actual intake was drawn from medical records. We compared the 2 assessment methods using a Spearman correlation coefficient. RESULTS: Twenty-three patients with TBI (moderate in 7 and severe in 16) were included in the study. Overall, there was a moderate positive correlation between the Penn State equation estimate and indirect calorimetry readings (correlation coefficient 0.457, p = 0.03); however, the correlation was weaker in severe TBI (correlation coefficient 0.174, p = 0.5) than in moderate TBI (correlation coefficient 0.929, p = 0.003). When compared to indirect calorimetry assessment, patients received 5.4% (p = 0.5) of required intake on the first day and 43.9% (p = 0.8) of required daily intake throughout their ICU stay. CONCLUSION: Patients with moderate or severe TBI in the ICU received less than 50% of their nutritional requirements. The difference between the Penn State equation and indirect calorimetry assessments was most noticeable for patients with severe TBI, which indicates that indirect calorimetry may be a more suitable tool for assessment of nutritional needs in this population.

Percutaneous Tracheostomy With a Demistifier Canopy in the COVID-19 Era: A Safe Technique in the Intensive Care Unit.

BACKGROUND: Endoscopic percutaneous tracheostomy (PT) is a safe technique that is performed frequently by otolaryngologists and intensivists. New challenges have been identified in order to maintain the safety of this procedure during the COVID-19 pandemic. A novel approach, using a modified demistifier canopy, was developed during the first wave of the pandemic and implemented for 17 consecutive percutaneous tracheostomies in order to enhance procedural safety. METHODS: A protocol was developed after performing a literature review of tracheostomy in COVID-19 patients. A multidisciplinary tracheostomy team was established, including the departments of otolaryngology, critical care, and respiratory therapy. Simulation was performed prior to each PT, and postoperative debriefings were done. RESULTS: A protocol and technical description of PT using a modified demistifier canopy covering was written and video documented. Data were collected on 17 patients who underwent this procedure safely in our tertiary care hospital. There were no procedure-related complications, and no evidence of COVID-19 transmission to any member of the health care team during the study period. CONCLUSION: As patients continue to recover from COVID-19, their need for tracheostomy will increase. The technique described provides a safe, multidisciplinary method of performing PT in COVID-19 patients.

IFN-gamma-induced MHC class II expression: transactivation of class II transactivator promoter IV by IFN regulatory factor-1 is regulated by protein kinase C-alpha.

Previous studies based on pharmacological evidence suggested a requirement for protein kinase C (PKC) activity in the regulation of IFN-gamma-induced MHC class II (MHC-II) expression. In the present study, we investigated the molecular mechanisms by which PKC-alpha modulates IFN-gamma-induced MHC-II expression in the mouse macrophage cell line RAW 264.7. Overexpression of a dominant-negative (DN) mutant of PKC-alpha inhibited the expression of IFN-gamma-induced MHC-II but had no effect on IFN-gamma-induced STAT1 nuclear translocation and DNA binding activity, as well as on the expression of inducible NO synthase, IFN consensus sequence binding protein, MHC class I, IFN regulatory factor (IRF)-1, and IFN-gamma-inducible protein-10. Further analysis showed that IFN-gamma-induced expression of the MHC class II transactivator (CIITA), a transcriptional coactivator essential for MHC-II expression, was inhibited in DN PKC-alpha-overexpressing cells. Studies with reporter constructs containing the promoter IV region of CIITA revealed that overexpression of a constitutively active mutant of PKC-alpha enhanced IRF-1, but not IRF-2, transcriptional activity. Furthermore, characterization of IRF-1 from both normal and DN PKC-alpha-overexpressing cells revealed differences in IRF-1 posttranslational modifications. Collectively, our data suggest a novel regulatory mechanism for IFN-gamma-induced MHC-II expression, whereby PKC regulates CIITA expression by selectively modulating the transcriptional activity of IRF-1.