Ouellette, Yves

Objective: The Society of Critical Care Medicine PICU Liberation ABCDEF (A–F) Campaign Collaborative aimed to implement best practices for analgesia (A), breathing (B), comfort/consciousness (C), delirium (D), early mobilization (E), and family engagement and empowerment (F). Our post hoc study of Mayo Clinic data sought to compare the pre-implementation rounding process, which used a nursing script organized by organ systems, with a novel, liberation-focused rounding process emphasizing A–F bundle elements. Design: Secondary analysis of pre- vs. post-implementation surveys collected by independent observers during rounds. Setting: Medical/surgical PICU in a quaternary-care, academic medical center during April to July 2017. Subjects: The observed participants included PICU physicians, nurses, respiratory therapists, pharmacists, and dietitians. Interventions: None. Measurements and Main Results: Survey responses from 145 team members pre-implementation and 67 post-implementation showed improved team satisfaction, communication, and understanding of daily plans (all p < 0.05). Respondents reported an increased frequency of discussions on bundle components A–E (all p < 0.01). Observations of 41 pre-implementation and 46 post-implementation rounds showed an increase in the frequency of discussion of all components of the bundle (all p < 0.01). However, this finding was not at the expense of increased duration of individual rounds since we failed to find a difference in pre- vs. post-implementation duration per patient (480 vs. 544 s per patient, p = 0.20). Conclusions: In 2017, around the time of introducing the nurse-led PICU Liberation rounding process to our practice, we found that after implementation, there was an associated increase in discussions about bundle elements and improved communications and satisfaction in team members.

OBJECTIVES To review, analyze, and synthesize the literature on endothelial dysfunction in critically ill children with multiple organ dysfunction syndrome and to develop a consensus biomarker-based definition and diagnostic criteria. DATA SOURCES Electronic searches of PubMed and Embase were conducted from January 1992 to January 2020, using a combination of medical subject heading terms and key words to define concepts of endothelial dysfunction, pediatric critical illness, and outcomes. STUDY SELECTION Studies were included if they evaluated critically ill children with endothelial dysfunction, evaluated performance characteristics of assessment/scoring tools to screen for endothelial dysfunction, and assessed outcomes related to mortality, functional status, organ-specific outcomes, or other patient-centered outcomes. Studies of adults or premature infants (≤36 weeks gestational age), animal studies, reviews or commentaries, case series with sample size ≤10, and non-English language studies with the inability to determine eligibility criteria were excluded. DATA EXTRACTION Data were abstracted from each eligible study into a standard data extraction form along with risk of bias assessment. DATA SYNTHESIS We identified 62 studies involving 84 assessments of endothelial derived biomarkers indirectly linked to endothelial functions including leukocyte recruitment, inflammation, coagulation, and permeability. Nearly all biomarkers studied lacked specificity for vascular segment and organ systems. Quality assessment scores for the collected literature were low. CONCLUSIONS The Endothelial Subgroup concludes that there exists no single or combination of biomarkers to diagnose endothelial dysfunction in pediatric multiple organ dysfunction syndrome. Future research should focus on biomarkers more directly linked to endothelial functions and with specificity for vascular segment and organ systems.

Pertussis has re-emerged in both developed and developing countries and is an ongoing public health problem, even in countries with high rates of vaccination. Pertussis encephalopathy is a known complication of the disease, but the pathophysiology of this complication and the role of the pertussis bacteria have not been elucidated. We report three confirmed cases of pertussis infant younger than 3 months of age with neurological complications including lethargy, encephalopathy, and seizures. In each case, the cerebrospinal fluid was positive for Bordetella pertussis as determined by polymerase chain reaction. One patient did not survive and two were discharged with a normal neurological exam on follow-up. The cases emphasize the importance of analyzing cerebrospinal fluid in cases of pertussis-associated encephalopathy including polymerase chain reaction.

The role of gap junctional intercellular communication during the inflammatory process is not well understood. In particular, the role of vascular connexins (gap junction proteins) in regulating blood flow in response to inflammatory agents such as lipopolysaccharide (LPS) has not been fully investigated. Our hypothesis is that agonist‐mediated vasoconstriction is dependent on the presence of connexin 40 (Cx40) within the microvessel wall. Wild‐type (WT) and Cx40 −/− animals were treated with LPS (15 mg/kg ip) or saline for 18 hours. Small mesenteric resistance arteries (190–220 μm) were isolated, mounted on glass cannulae, pressurized at 60 mmHg with no lumen flow and placed on the stage of an inverted microscope. External arteriolar diameter was measured and concentration‐response curves to phenylephrine (PE, 10 −9 −10 −4 M) and to extracellular Ca 2+ (0 to 2 mM) under depolarizing conditions (120 mM K + ) were conducted. The half‐maximal effect (EC 50 ) was determined for each dose response curve. LPS treatment resulted in hyporesponsiveness to PE in WT mice (EC 50 2.07±0.45 mM vs 0.56±0.15 mM in shams) but resulted in hyperresponsiveness in Cx40 −/‐ (EC 50 0.27±0.03 mM vs 3.15±1.50 mM in shams). However, LPS treatment resulted in hyporesponsiveness to Ca 2+ in both WT mice (EC 50 0.39±0.03 mM vs 0.23±0.01mM in shams) and Cx40 −/− (EC 50 0.75±0.24 mM vs 0.23±0.03 mM in shams). We conclude that agonist‐mediated but not Ca 2+ ‐mediated vasoconstriction is modulated by the presence of Cx40.

Myocardial performance is depressed in both sepsis and endotoxin shock. Altered gap junctional coupling of ventricular myocytes may play an important role in myocardial dysfunction during sepsis. Since phosphorylation is known to regulate turnover of gap junction protein, we hypothesized that the phosphorylation status of connexin 43 (Cx43) is altered in vivo following exposure to lipopolysacccharide (LPS). Saline or LPS (25 mg/kg; E. coli 055:B5) was injected intraperitoneally into c57bl/6 mice. At 18 h, hearts were excised and snap frozen on dry ice. Tissue was homogenized in Triton X‐100 lysate buffer, centrifuged and prepared for Western blot. Cx43 was immunoprecipitated from the supernatant and tyrosine phosphorylation of Cx43, detected by immunoblot. Phosphorylated forms of Cx43 are seen as three major bands on Western blots. After LPS treatment, there is a decrease in the intensity of the fastest migrating band (Cx43‐P0) and an increase in the two slower migrating forms, (Cx43‐P1 and Cx43‐P2). This corresponds to a decrease in tyrosine phosphorylation of Cx43. LPS results in decrease in myocardial Cx43 tyrosine phosphorylation possibly mediating LPS‐induced myocardial dysfunction.

We studied the effects of TNF on cell‐to‐cell communication in HeLa cells expressing vascular connexin 37, 40 or 43. HeLa cells were treated with TNF (20 ng/ml) for up to 2 h. In dye‐transfer experiments, carboxyfluroscein (HeLaCx40 and HeLaCx43) or Alexa Fluor‐480 (HeLaCx37) was injected into one cell for 10 s and cell transfer allowed to proceed for 10 m and the number of labeled cells counted. Cell lysates were prepared in Triton X‐100 lysate buffer and detergent‐soluble fractions collected. Cx37, 40 and 43 were detected by Western blot. After 1 hour, TNF treatment resulted in near total loss of dye‐coupling in HeLaCx37 and HeLaCx43 (p<0.02, n=14‐16) and remained constant up to 2 hours. Dye coupling in HeLaCx40 cells remained unchanged after 1 hour and decreased after 2 hours (p<0.05, n=10). Western blots indicated that TNF treatment did not affect detergent solubility of Cx40 and 43. However, TNF caused a significant increase in detergent solubility of Cx37. These results suggest that inflammatory mediators affect connexins differently, and that the loss of Cx37 function may be due to the loss of detergent resistance.