Conducting Prospective Research as a Trainee: Experiences with the DRIVE-SAFE Study.

Conducting clinical research during a 2-year critical care fellowship is a challenging endeavor. Fellows are often met with multiple barriers when considering clinical research projects during fellowship, including time, mentorship, resources, and clinical support. This paper presents the perspective and experiences of a group of critical care fellows who conducted the DRIVE-SAFE (Driving Pressure in Assisted Ventilation as a Predictor for Successful Liberation from Invasive Mechanical Ventilation) feasibility study, which aimed to determine measurable physiological variables that could be associated with lung injury and affect duration of mechanical ventilation. This paper provides a guide for trainees on how to conduct prospective clinical research at the bedside. We describe three key steps, including formulating a research question, developing appropriate methodology, and establishing outcomes. We also present the challenges that trainees may encounter when conducting prospective studies and how to overcome these challenges with proper mentorship, training, and collaboration with key stakeholders. These perspectives may provide useful guidance for current and future trainees interested in conducting prospective clinical research at the bedside.

Internal jugular vein ultrasound for the diagnosis of hypovolemia and hypervolemia in acutely ill adults: a systematic review and meta-analysis.

Accurate volume status assessments allow physicians to rapidly implement therapeutic measures in acutely unwell patients. However, existing bedside diagnostic tools are often unreliable for assessing intravascular volume. We searched PUBMED, EMBASE, CENTRAL, and Web of Science for English language articles without date restrictions on January 20, 2022. Studies reporting the diagnostic accuracy of IJV-US for hypovolemia and/or hypervolemia in an acute care setting were screened for inclusion. We included studies using any method of IJV-US assessment as the index test, compared against any reference standard. We fitted hierarchical summary receiver operating characteristic (HSROC) models for meta-analysis of diagnostic test accuracy, separately for hypovolemia and hypervolemia. Two reviewers independently extracted data and assessed risk of bias using QUADAS-2. We assessed certainty of evidence using the GRADE approach. A total of 26 studies were included, of which 19 studies (956 patients) examined IJV-US for hypovolemia and 13 studies (672 patients) examined IJV-US for hypervolemia. For the diagnosis of hypovolemia, IJV-US had a pooled sensitivity of 0.82 (95% CI 0.76 to 0.87; moderate-certainty evidence) and specificity of 0.82 (95% CI 0.73 to 0.88; moderate-certainty evidence). Measurement of IJV collapsibility indices had higher diagnostic accuracy (sensitivity 0.85, 95% CI 0.80 to 0.89; specificity 0.78, 95% CI 0.64 to 0.88) than static IJV indices (sensitivity 0.73, 95% CI 0.60 to 0.82; specificity 0.70, 95% CI 0.48 to 0.86). For the diagnosis of hypervolemia, IJV-US had a pooled sensitivity of 0.84 (95% CI 0.70 to 0.92; moderate-certainty evidence) and specificity of 0.70 (95% CI 0.55 to 0.82; very low-certainty evidence). IJV-US has moderate sensitivity and specificity for the diagnosis of hypervolemia and hypovolemia. Randomized controlled trials are needed to determine the role of IJV-US for guiding therapeutic interventions aimed at optimizing volume status.

Development of a continuous cell line from larval Atlantic cod (Gadus morhua) and its use in the study of the microsporidian, Loma morhua.

In vitro cell culture methods are crucial for the isolation, purification and mass propagation of intracellular pathogens of aquatic organisms. Cell culture infection models can yield insights into infection mechanisms, aid in developing methods for disease mitigation and prevention, and inform commercial-scale cultivation approaches. This study details the establishment of a larval cell line (GML-5) from the Atlantic cod (Gadus morhua) and its use in the study of microsporidia. GML-5 has survived over 100 passages in 8 years of culture. The line remains active and viable between 8 and 21°C in Leibovitz-15 (L-15) media with 10% foetal bovine serum and exhibits a myofibroblast phenotype as indicated by immuno-positive results for vimentin, α-smooth muscle actin, collagen I and S-100 proteins, while being desmin-negative. GML-5 supports the infection and development of two microsporidian parasites, an opportunistic generalist (Anncaliia algerae) and cod-specific Loma morhua. Using GML-5, spore germination and proliferation of L. morhua was found to require exposure to basic pH and cool incubation temperatures (8°C), in contrast to A. algerae, which required no cultural modifications. Loma morhua-associated xenoma-like structures were observed 2 weeks postexposure. This in vitro infection model may serve as a valuable tool for cod parasitology and aquaculture research.

Non-essential blood tests in the intensive care unit: a prospective observational study.

PURPOSE: Non-essential blood testing in the acute care setting can be a prominent source of morbidity, patient discomfort, increased workload for the healthcare provider, and wasteful spending. The magnitude of such non-essential blood testing has not been well described. We aimed to measure the extent of unnecessary blood testing in a 33-bed intensive care unit (ICU) at a tertiary-care teaching hospital in Ontario, Canada. METHODS: Over a period of four weeks, all ICU attending physicians were asked to select, from a comprehensive list, blood tests that they deemed essential to the appropriate care for each of their patients on the following day. The actual tests processed on the following day were recorded. Descriptive statistics were used to determine what proportion of all processed tests were deemed essential blood tests. The association between patient characteristics and the total cost of unnecessary tests was assessed using the Wilcoxon rank-sum test and the Spearman correlation coefficient, as appropriate. RESULTS: Nine attending physicians provided input for a total of 81 patient days. In 65 (80%) of these days, at least one test was considered non-essential. Physicians deemed only 338 (48.7%) of 694 processed blood tests as essential, which amounted to $2,243.41 (46.0%) out of an overall cost of $4,882.11. Patients' age, sex, mechanical ventilation status, and treatment with vasoactive drugs on the study day were not associated with the number of non-essential tests. CONCLUSIONS: Attending physicians deemed a substantial proportion of the blood tests processed in a tertiary care ICU setting as unnecessary. Furthermore, the non-essential tests incurred substantial additional cost. Further work is required to gain a better understanding of the underlying factors contributing to these wasteful practices.

Senescence-associated ß-galactosidase staining in fish cell lines and primary cultures from several tissues and species, including rainbow trout coelomic fluid and milt.

Cell lines and primary cultures from several teleost tissues and species were stained for senescence-associated ß-galactosidase (SA ß-Gal), revealing four general outcomes. (1) For long-standing fish cell lines that can be considered immortal, little or no SA ß-Gal staining was observed, regardless of the culture conditions. (2) For a new walleye cell line from the bulbus arteriosus (WEBA), most cells stained for SA ß-Gal even after 40 passages. This suggested that high SA ß-Gal activity was a unique property of WEBA, perhaps reflecting their endothelial character, rather than cellular senescence. (3) For cell lines developed from the walleye caudal fin and from somatic cells in rainbow trout coelomic fluid, no SA ß-Gal staining was observed in the earliest cultures to over 70 passages later. This suggested that cells from these anatomical sites do not undergo senescence in vitro. (4) By contrast, for cell lines developed from the walleye brain and from somatic cells in rainbow trout milt, most cells in the early-stage cultures stained for SA ß-Gal, but as these were developed into cell lines, SA ß-Gal-negative cells became dominant. This suggested that if cellular senescence occurred in vitro, this happened early in these cultures and subsequently a few SA ß-Gal-negative cells went onto to form the cell line. Overall, the presence of SA ß-Gal-positive cells in cultures could be interpreted in several ways, whereas their absence predicted that in these cultures, cells would proliferate indefinitely.

Derivation of a continuous myogenic cell culture from an embryo of common killifish, Fundulus heteroclitus.

The common killifish or mummichog (Fundulus heteroclitus) is an estuarine teleost increasingly used in comparative physiology, toxicology and embryology. Their ability to withstand extreme environmental conditions and ease of maintenance has made them popular aquatic research organisms. Scientific advances with most popular model organisms have been assisted with the availability of continuous cell lines; however, cell lines from F. heteroclitus appear to be unavailable. The development of a killifish cell line, KFE-5, derived from the mid trunk region of a late stage embryo is described here. KFE-5 grows well in Leibovitz's L-15 media with 10% fetal bovine serum (FBS). This cell line has been passaged over 60 times in a span of three years, and cells at various passages have been successfully cryopreserved and thawed. The cells are mostly fibroblastic but contain myogenic cells that differentiate into mono-, bi- and multi-nucleated striated myocytes. Immunofluorescence detection of muscle specific antigens such as α-actinin, desmin, and myosin confirms KFE-5 as a myogenic cell line. KFE-5 has a temperature preference for 26-28°C and has been shown to withstand temperatures up to 37°C. The cell line responds to chemical signals including growth factors, hormones and extracellular matrix components. KFE-5 could thus be useful not only for mummichog's thermobiology but also for studies in fish muscle physiology and development.