Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

The involvement of older inpatients in medical student education

Objectives

To examine older inpatients’ experiences with medical student education, their views on future interactions, and to seek their opinion on the most important curricular topics related to geriatric medicine.

Methods

The study involved 112 non-confused inpatients older than 65 years of age, who completed a uniformed questionnaire on the day of their discharge from a teaching hospital.

Results

The mean age was 81 years, with equal number of male and female participants. 57% interacted with the students during their admission, the majority being interviewed and examined. Almost all (92%) of these patients described their experience as positive, some described it as time-consuming (23%), repetitive (19%) and tiresome (9%). 92% of all participants agreed that the older patients should be part of medical students’ education. Dementia, cardiac conditions, cancer, arthritis, isolation/loneliness were highlighted as the most important topics to teach medical students related to geriatric medicine, while patience and listening were listed as important skills. They suggested practical, easily implemented advice for the improvement of the interaction between students and older patients; including allowing more time for interactions and for students to speak louder.

Conclusions

Older patients felt positively about their interactions with medical students, and believed that older patients should be involved in medical student education. As well as medical conditions such as dementia, cardiac disease and cancer, these patients highlighted isolation and loneliness as important topics for undergraduate geriatric medical education, implying that students should learn about broader aspects of older patients’ health and wellbeing.

A comparative evaluation of the effect of polymer chemistry and fiber orientation on mesenchymal stem cell differentiation

Bioengineered tissue scaffolds in combination with cells hold great promise for tissue regeneration. The aim of this study was to determine how the chemistry and fiber orientation of engineered scaffolds affect the differentiation of mesenchymal stem cells (MSCs). Adipogenic, chondrogenic, and osteogenic differentiation on aligned and randomly orientated electrospun scaffolds of Poly (lactic‐co‐glycolic) acid (PLGA) and Polydioxanone (PDO) were compared. MSCs were seeded onto scaffolds and cultured for 14 days under adipogenic‐, chondrogenic‐, or osteogenic‐inducing conditions. Cell viability was assessed by alamarBlue metabolic activity assays and gene expression was determined by qRT‐PCR. Cell‐scaffold interactions were visualized using fluorescence and scanning electron microscopy. Cells grew in response to scaffold fiber orientation and cell viability, cell coverage, and gene expression analysis showed that PDO supports greater multilineage differentiation of MSCs. An aligned PDO scaffold supports highest adipogenic and osteogenic differentiation whereas fiber orientation did not have a consistent effect on chondrogenesis. Electrospun scaffolds, selected on the basis of fiber chemistry and alignment parameters could provide great therapeutic potential for restoration of fat, cartilage, and bone tissue. This study supports the continued investigation of an electrospun PDO scaffold for tissue repair and regeneration and highlights the potential of optimizing fiber orientation for improved utility. © 2016 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2843–2853, 2016.

Safety profile of dalfampridine extended release in multiple sclerosis: 5-year postmarketing experience in the United States

BACKGROUND

Dalfampridine extended release tablets (dalfampridine-ER; prolonged-, modified, or sustained-release fampridine outside the US), 10 mg twice daily, was approved by the US Food and Drug Administration (FDA) in January 2010 to improve walking in people with multiple sclerosis, as determined by an increase in walking speed.

OBJECTIVE

To provide a descriptive analysis of reported adverse events (AEs) for commercially available dalfampridine-ER from March 2010 through March 31, 2015.

METHODS

Five-year postmarketing data for dalfampridine-ER were available from the exposure of approximately 107,000 patients in the US (103,700 patient-years). Commonly reported AEs (≥2% of all reported AEs) and serious AEs were determined. The incidence of reported seizures was determined and the events were further investigated.

RESULTS

Among the 107,000 patients exposed to dalfampridine-ER (70% female; mean age 52.1), the most common AEs were dizziness (3.7%), insomnia (3.2%), balance disorder (3%), fall (2.4%), headache (2.4%), nausea (2.1%), and urinary tract infection (2%). Other common AEs were drug ineffectiveness (5.8%), gait disturbance (4.6%), and inappropriate dosing (3.1%). Serious AEs included rare anaphylactic reactions (five cases) and drug hypersensitivity reactions (eight cases). A total of 657 seizure cases were reported (6.3/1,000 patient-years); of these, 324 were medically confirmed (3.1/1,000 patient-years). Incidence of reported seizures was stable over time. Duration of treatment prior to a seizure ranged from a single dose to >4 years; 12% of the seizures occurred within a week of starting treatment.

CONCLUSION

The 5-year US postmarketing safety data of dalfampridine-ER is consistent with the safety profile observed in clinical trials. Incidence of reported seizures remained stable over time. Since commercial availability in March 2010, a warning regarding the risk of anaphylaxis and severe allergic reactions was added to the US prescribing information.

[Working overseas and cardiovascular diseases: application of a screening method on Oil&Gas employees]

Working overseas is a reality for decades in the Oil&Gas Industry and many noxae impact on the cardiovascular system. In fitness to work evaluation the physician should consider besides the conventional risk factors, the presence of cardiovascular diseases, and prevent their evolution. A cardiovascular screening and follow up after 2 years was carried out on 42 Oil&Gas employees, over 45 of age, during medical fitness to work. The main tests were ECG, exercise tolerance test (ETT) and echocardiocolordoppler, completed with other instrumental tests. Cardiovascular diseases causing unfitness to working overseas occurred in 7%, blood hypertension in 23%. The screening permitted to diagnose and correct acute cardiovascular diseases, that caused unfitness to work, and disease that can get worse related to occupational risk. Moreover it was fundamental for evaluation of fitness and timing of health surveillance.