Early goal enteral nutrition associated with decreased in-hospital death in mechanically ventilated critically ill adults: a retrospective cohort study.

INTRODUCTION: Early enteral nutrition (EN) in critically ill adult patients is thought to improve mortality and morbidity; expert guidelines recommend early initiation of EN in critically ill adults. However, the ideal schedule and dose of EN remain understudied. STUDY OBJECTIVE: Our objective was to evaluate the relationship between achieving 70% of recommended EN within 2 days of intubation ('early goal EN') and clinical outcomes in mechanically ventilated medically critically ill adults. We hypothesised that early goal EN would be associated with reduced in-hospital death. METHODS: We conducted a retrospective cohort study of mechanically ventilated adult patients admitted to our medical intensive care unit during 2013-2019. We assessed the proportion of recommended total EN provided to the patient each day following intubation until extubation, death or 7 days whichever was shortest. Patients who received 70% or more of their recommended total daily EN within 2 days of intubation (ie, 'baseline period') were considered to have achieved 'early goal EN'; these patients were compared with patients who did not ('low EN'). The primary outcome was in-hospital death; secondary outcomes were successful extubation and discharge alive. RESULTS: 938 patients met eligibility criteria and survived the baseline period. During the 7-day postintubation period, 64% of all patients reached 70% of recommended daily calories; 33% of patients achieved early goal EN. In unadjusted and adjusted models, early goal EN versus low EN was associated with a lower incidence of in-hospital death (subdistribution HR (SHR) unadjusted=0.63, p=0.0003, SHR adjusted=0.73, p=0.02). Early goal EN was also associated with a higher incidence of successful extubation (SHR unadjusted=1.41, p<0.00001, SHR adjusted=1.27, p=0.002) and discharge alive (SHR unadjusted=1.54, p<0.00001, SHR adjusted=1.24, p=0.02). CONCLUSIONS: Early goal EN was associated with significant improvement in clinical metrics of decreased in-hospital death, increased extubation and increased hospital discharge alive.

Transition to multiple mini interview (MMI) interviewing for medical school admissions.

INTRODUCTION: The multiple mini interview (MMI) has been incorporated into the holistic review process in the selection of students to US medical schools. The MMI has been used to evaluate interpersonal and intrapersonal attributes which are deemed as necessary for future physicians. We hypothesized that there would be little difference in overall MMI evaluation data compared with traditional interview ratings. METHODS: The University of North Carolina School of Medicine developed an interview process that included a traditional interview and MMI format during the 2019 admissions cycle. Evaluation data along with key demographic variables for 608 MD program applicants were analyzed using descriptive and inferential statistical analyses. RESULTS: The MMI format slightly favored female over male applicants (p = 0.002) but did not select for or against applicants based on age, race/ethnicity, underserved/rural area upbringing, or indicators of disadvantage. Out of 608 applicants, 356 (59%) completed a post-interview survey in which the experience was positively rated. DISCUSSION: Based on our experience, the use of a hybrid model of traditional interviews complemented with MMI stations provided greater details in the assessment of medical school applicants while obtaining equivalent data and acceptability amongst applicants.

Validation of a Self-Monitoring Tool for Use in Exercise Therapy.

BACKGROUND: Aerobic exercise at a subsymptom heart rate has been recommended as therapy for postconcussion syndrome. Assessing adherence with an accurate heart rate-monitoring instrument is difficult, limiting the proliferation of large-scale randomized controlled trials. OBJECTIVE: To evaluate the validity of the Fitbit Charge HR compared with electrocardiogram (EKG) to monitor heart rate during a treadmill-based exercise protocol. DESIGN: A methods comparison study. SETTING: Sports medicine research center within a tertiary care institution. PARTICIPANTS: A convenience sample of 22 healthy participants (12 female) aged 18-26 years (mean age: 22 ± 2 years). METHODS: Fitbit Charge HR heart rate measurements were compared with EKG data concurrently collected while participants completed the Buffalo Concussion Treadmill Test. MAIN OUTCOME MEASURES: Agreement between Fitbit Charge HR and EKG was assessed by intraclass correlation coefficients (ICC3,1), Bland-Altman limits of agreement, and percent error. RESULTS: We observed a strong single-measure absolute agreement between Fitbit Charge HR and EKG (intraclass correlation coefficient = 0.83; 95% confidence interval 0.67-0.90). Fitbit Charge HR underestimated heart rate compared with EKG (mean difference = -6.04 bpm; standard deviation = 10.40 bpm; Bland-Altman 95% limits of agreement = -26.42 to 14.35 bpm). A total of 69.9% of Fitbit heart rate measurements were within 10% error compared with EKG, and 91.5% of all heart rate measurements were within 20% error. CONCLUSIONS: Although the mean bias in measuring heart rate was relatively small, the limits of agreement between the Fitbit Charge HR and EKG were broad. Thus, the Fitbit Charge HR would not be a suitable option for monitoring heart rate within a narrow range. For the purposes of postconcussion exercise therapy, the relatively inexpensive cost, easy implementation, and low maintenance make Fitbit Charge HR a viable option for assessing adherence to an exercise program when expensive clinical equipment is unavailable. LEVEL OF EVIDENCE: II.

Does topology drive fiber polymerization?

We have developed new procedures to examine the early steps in fibrin polymerization. First, we isolated fibrinogen monomers from plasma fibrinogen by gel filtration. Polymerization of fibrinogen monomers differed from that of plasma fibrinogen. The formation of protofibrils was slower and the transformation of protofibrils to fibers faster for the fibrinogen monomers. Second, we used formaldehyde to terminate the polymerization reactions. The formaldehyde-fixed products obtained at each time point were examined by dynamic light scattering and transmission electron microscopy (TEM). The data showed the formaldehyde-fixed products were stable and representative of the reaction intermediates. TEM images showed monomers, short oligomers, protofibrils, and thin fibers. The amount and length of these species varied with time. Short oligomers were less than 5% of the molecules at all times. Third, we developed models that recapitulate the TEM images. Fibrin monomer models were assembled into protofibrils, and protofibrils were assembled into two-strand fibers using Chimera software. Monomers were based on fibrinogen crystal structures, and the end-to-end interactions between monomers were based on D-dimer crystal structures. Protofibrils assembled from S-shaped monomers through asymmetric D:D interactions were ordered helical structures. Fibers were modeled by duplicating a protofibril and rotating the duplicate 120° around its long axis. No specific interactions were presumed. The two protofibrils simply twisted around one another to form a fiber. This model suggests that the conformation of the protofibril per se promotes the assembly into fibers. These findings introduce a novel mechanism for fibrin assembly that may be relevant to other biopolymers.