Optimisation of medication reconciliation using queueing theory: a computer experiment.

BACKGROUND: Medication reconciliation (MedRec) in hospitals is an important tool to enhance the continuity of care, but completing MedRec is challenging. AIM: The aim of this study was to investigate whether queueing theory could be used to compare various interventions to optimise the MedRec process to ultimately reduce the number of patients discharged prior to MedRec being completed. Queueing theory, the mathematical study of waiting lines or queues, has not been previously applied in hospital pharmacies but enables comparisons without interfering with the baseline workflow. METHOD: Possible interventions to enhance the MedRec process (replacing in-person conversations with telephone conversations, reallocating pharmacy technicians (PTs) or adjusting their working schedule) were compared in a computer experiment. The primary outcome was the percentage of patients with an incomplete discharge MedRec. Due to the COVID-19 pandemic, it was possible to add a real-life post hoc intervention (PTs starting their shift later) to the theoretical interventions. Descriptive analysis was performed. RESULTS: The queueing model showed that the number of patients with an incomplete discharge MedRec decreased from 37.2% in the original scenario to approximately 16% when the PTs started their shift 2 h earlier and 1 PT was reassigned to prepare the discharge MedRec. The number increased with the real-life post hoc intervention (PTs starting later), which matches a decrease in the computer experiment when started earlier. CONCLUSION: Using queueing theory in a computer experiment could identify the most promising theoretical intervention to decrease the percentage of patients discharged prior to MedRec being completed.

Promising results of a new treatment in patients with bowel obstruction in colorectal surgery.

INTRODUCTION: Bowel obstruction increases risk of emergency surgery and leads to suboptimal physical and nutritional condition. Preventing emergency surgery and prehabilitation might improve outcomes. This pilot study aimed to examine the effect of a multimodal obstruction protocol for bowel obstruction patients on the risk of emergency surgery and postoperative morbidity and mortality. MATERIALS AND METHODS: All bowel obstruction patients treated according to the obstruction protocol in the period 2013-2017 were included in this uncontrolled observational cohort study. Benign and malignant causes of bowel obstruction were included. The protocol consisted of: 1. specific dietary adjustments to reduce prestenotic dilatation, 2. oral laxatives and 3. prehabilitation. Emergency surgery and postoperative morbidity and mortality rates were compared to known rates from the literature. RESULTS: Sixty-one patients were included: 44 (72%) were treated for colorectal cancer and 17 (28%) for Crohn's disease or diverticulitis. Four patients (7%) underwent emergency surgery. Primary anastomosis was constructed in 49 out of 57 elective patients (86%). Severe complications (Clavien-Dindo ≥ III) occurred in four patients (7%). No bowel perforation, anastomotic leakages or 30-day mortality was observed. These rates were much lower than rates reported in the literature after surgery for colorectal cancer (3% bowel perforation, 8% anastomotic leakage, 4% 30-day mortality, 15% severe complications) and benign disease (30-day mortality 17%, severe complications 7%). CONCLUSION: Using the obstruction protocol in patients with bowel obstruction reduced emergency surgery and postoperative morbidity and mortality in this pilot study. This protocol seems to be a viable and efficient alternative to emergency surgery.

On the prosthetic group(s) of component II from nitrogenase. EPR of the Fe-protein from Azotobacter vinelandii.

The EPR spectrum of the reduced Fe-protein from nitrogenase has been reinvestigated. The dependences on temperature, microwave power, and microwave frequency all suggest that the observed signal represents a magnetically isolated [4Fe-4S]1+(2+;1+) cluster. Also, the signal can be simulated assuming a simple, g-strained S = 1/2 system. However, the integrated intensity amounts to no more than 0.2 spins per protein molecule. It is, therefore, impossible that Fe-protein preparations contain a single type of [4Fe-4S] cluster.

The importance of quantitative Mössbauer spectroscopy of MoFe-protein from Azotobacter vinelandii.

The Mössbauer spectra of MoFe-protein of Azotobacter vinelandii, as isolated under dithionite and taken at temperatures from 125 K to 175 K, are the sums of four resolved quadrupole doublets. Our results indicate that the currently accepted interpretation of these doublets can be questioned. Our data reduction method converts the Mössbauer transmission spectra to source lineshape deconvolved absorption spectra linear in iron. We used these absorption spectra to determine the stoichiometry of the Fe clusters in MoFe-protein and we obtained much better fits if we assumed that there are four iron atoms in the 'Fe2+, doublet, two iron atoms in the 'S' doublet, twelve iron atoms in the 'D' doublet and sixteen iron atoms in the 'M' doublet. Therefore we propose that the MoFe-cofactor contains one molybdenum and eight iron atoms ('M'). We also argue that none of the previous Mössbauer spectroscopic studies have been performed on the highest-activity preparation now obtainable, nor has there been any study to prove that the Mössbauer spectra are independent of activity. We consider that the Mössbauer spectroscopic studies of the MoFe-protein of nitrogenase are a re-opened and unsolved problem.

Fully active Fe-protein of the nitrogenase from Azotobacter vinelandii contains at least eight iron atoms and eight sulphide atoms per molecule.

The Fe-protein of the Azotobacter vinelandii nitrogenase enzyme complex contains a variable iron and sulphide content. The iron and sulphide content of the protein is dependent upon the specific activity. Up to a specific activity of 1000 nmol C2H4 produced X min-1 X mg Av-1(2), three iron and three sulphide atoms per molecule Av2 are found. At specific activities above 1000 nmol C2H4 produced X min-1 X mg Av-1(2), a linear relationship between specific activity and iron and sulphide content of Av2 is found. The maximum values found are 8.8 iron atoms and 8.6 sulphide atoms/molecule at a specific activity of 2250 nmol C2H4 produced X min-1 X mg Av-1(2). Also the experimental molar absorption coefficients at 430 nm of the oxidized and reduced forms depend on the specific activity. The highest values found are 15.9 mM-1 cm-1 and 9.1 mM-1 cm-1, respectively. Since occasionally the preparations with specific activities around 3000 nmol X min-1 X mg-1 are isolated which contain more than 10 iron atoms and 11 sulphide atoms per molecule, it cannot be excluded that under certain physiological conditions Av2 contains even more than two [4 Fe-4 S] clusters. The addition of MgATP induces a conformational change in the Fe-protein which results in a higher reactivity with iron chelators. But irrespective of the specific activity, the amount of iron extracted from the protein after addition of MgATP never exceeds four atoms/molecule. The results are discussed with respect to the present molecular model of the Fe-protein.