Effects of increasing nurse staffing on missed nursing care.

BACKGROUND: Inadequate nurse staffing has been reported to lead nurses to omit required nursing care. In South Korea, to reduce informal caregiving by patient families and sitters and to improve the quality of nursing care, a public hospital operated by the Seoul Metropolitan Government has implemented a policy of increasing nurse staffing from 17 patients per registered nurse to 7 patients per registered nurse in 4 out of 13 general nursing units since January 2013. AIM: The study aims to compare missed nursing care (omission of required care) in high-staffing (7 patients per nurse) units vs. low-staffing (17 patients per nurse) units to examine the effects of nurse staffing on missed care. METHODS: A nurse survey conducted in July 2013 targeted all staff nurses in all four high-staffing and all nine low-staffing units; 115 nurses in the high-staffing units (response rate = 94.3%) and 117 nurses in the low-staffing units (response rate = 88.6%) participated. Missed nursing care was measured using the MISSCARE survey that included 24 nursing care elements. Nurses were asked how frequently they had missed each element on a 4-point scale from 'rarely' to 'always'. RESULTS: Overall, nurses working in high-staffing units had a significantly lower mean score of missed care than those in low-staffing units. Seven out of 24 nursing care elements were missed significantly less often in high-staffing (vs. low-staffing) units: turning, mouth care, bathing/skin care, patient assessments in each shift, assistance with toileting, feeding and setting up meals. CONCLUSION: The findings suggest that increasing nurse staffing is associated with a decrease in missed care. Less omission of required nursing care is expected to improve nursing surveillance and patient outcomes, such as patient falls, pressure ulcers and pneumonia. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Adequate nurse staffing should be ensured to reduce unmet nursing needs and improve patient outcomes.

A residence-time distribution analysis of the hydrodynamics within the intestine in man during a regional single-pass perfusion with Loc-I-Gut: in-vivo permeability estimation.

The goal of this study was to determine the most appropriate hydrodynamic model for the Loc-I-Gut in-vivo perfusion system. The general mixing-tank-in-series model, which can approximate single mixing tank and laminar and plug-flow hydrodynamics, was fitted to the observed experimental residence-time distribution curves for the non-absorbable marker [14C]PEG 4000. The residence-time distribution analysis shows that the hydrodynamics of the perfusion solution within the jejunal segment in man is well approximately by a model containing on average between 1-2 mixing tanks in series. The solution is well mixed when using perfusion rates of 2.0, 3.0 and 6.0 mL min-1. The average mean residence time estimates from the fitted residence-time distribution were 12 +/- 7.6, 15 +/- 4.2 and 7.7 +/- 4.6 min, respectively, at these three perfusion rates. The mean volumes of the segment (Vs) were 25 +/- 15, 45 +/- 12 and 46 +/- 27 mL, respectively. There were no statistical differences between 2.0, 3.0 and 6.0 mL min-1 in respect of the number of mixing tanks (n) and mean residence times. This residence-time distribution analysis indicates that the luminal fluid in the Loc-I-Gut perfusion system is well-mixed, and that permeability calculations based on the well-mixed assumption most closely approximate the actual local (average) membrane permeability within the perfused segment.

A Macintosh software package for simulation of human red blood cell metabolism.

We have developed a computer software package for Macintosh to simulate the metabolism and hemoglobin binding affinity of human red blood cell. The model is capable of simulating hemoglobin binding of ligands, metabolite concentrations, and metabolic fluxes at physiological steady state and in response to extracellular parameter variations, such as pH, osmolarity, glucose, and adenine concentrations. The kinetic parameters of enzymes, extracellular conditions, and initial intracellular metabolite concentrations can be specified by the user in order to model a particular situation. The software is use friendly, utilizing menu, window, and mouse to interact with the user. It also provides a pathway map of the red cell, which allows a direct access to enzyme kinetics by clicking the enzymes in the map.

Model complexity has a significant effect on the numerical value and interpretation of metabolic sensitivity coefficients.

Logarithmic sensitivity coefficients were promulgated for the analysis of metabolic regulation about 20 years ago. Interest in their use has risen significantly since their introduction. However, no comprehensive evaluation of the utility of these metabolic sensitivity coefficients is available for realistic metabolic models. In this study, logarithmic sensitivity coefficients calculated from three progressively simpler metabolic models of red blood cell metabolism were compared. Two simpler models were obtained from a comprehensive red cell model by first removing volume regulation, and second by removing two pathways. The comparisons of sensitivity coefficients obtained for these three models showed that model complexity has significant effects on the numerical values and interpretation of the metabolic sensitivity coefficients. Additionally, it was found that the physiochemical volume regulatory mechanism, namely electroneutrality and osmotic balances, play an important role in the red cell metabolic flux control. In general, there is no proportionate relationship between sensitivity coefficients calculated from the three different red cell metabolic models or other simple red cell models reported in the early literature. Some sensitivity coefficients determined by different models even have opposite signs. Thus, analysis of incomplete metabolic models can be seriously misleading and produce inappropriate indicators of the characteristics of a full model for the same metabolic network.

A comprehensive model of human erythrocyte metabolism: extensions to include pH effects.

A mathematical model of the human erythrocyte, which accounts both for metabolism of the cell and its interactions with the environment, has been constructed. The pH dependence of enzyme activities is added to a previous model, which accounts for glycolysis, pentose phosphate pathway, nucleotide synthesis, membrane transport, osmotic balance, and conditions of electroneutrality. The extended model predicts well the dynamic behavior of the red cell in response to glucose depletion and pH variation.

Effects of food and sucralfate on a single oral dose of 500 milligrams of levofloxacin in healthy subjects.

The effects of food and sucralfate on the pharmacokinetics of levofloxacin following the administration of a single 500-mg oral dose were investigated in a randomized, three-way crossover study with young healthy subjects (12 males and 12 females). Levofloxacin was administered under three conditions: fasting, fed (immediately after a standardized high-fat breakfast), and fasting with sucralfate given 2 h following the administration of levofloxacin. The concentrations of levofloxacin in plasma and urine were determined by high-pressure liquid chromatography. By noncompartmental methods, the maximum concentration of drug in serum (Cmax), the time to Cmax (Tmax), the area under the concentration-time curve (AUC), half-life (t1/2), clearance (CL/F), renal clearance (CLR), and cumulative amount of levofloxacin in urine (Ae) were estimated. The individual profiles of the drug concentration in plasma showed little difference among the three treatments. The only consistent effect of the coadministration of levofloxacin with a high-fat meal for most subjects was that levofloxacin absorption was delayed and Cmax was slightly reduced (Tmax, 1.0 and 2.0 h for fasting and fed conditions, respectively [P = 0.002]; Cmax, 5.9 +/- 1.3 and 5.1 +/- 0.9 microg/ml [90% confidence interval = 0.79 to 0.94] for fasting and fed conditions, respectively). Sucralfate, which was administered 2 h after the administration of levofloxacin, appeared to have no effect on levofloxacin's disposition compared with that under the fasting condition. Mean values of Cmax and AUC from time zero to infinity were 6.7 +/- 3.2 microg/ml and 47.9 +/- 8.4 microg x h/ml, respectively, following the administration of sucralfate compared to values of 5.9 +/- 1.3 microg/ml and 50.5 +/- 8.1 microg x h/ml, respectively, under fasting conditions. The mean t1/2, CL/F, CLR, and Ae values were similar among all three treatment groups. In conclusion, the absorption of levofloxacin was slightly delayed by food, although the overall bioavailability of levofloxacin following a high-fat meal was not altered. Finally, sucralfate did not alter the disposition of levofloxacin when sucralfate was given 2 h after the administration of the antibacterial agent, thus preventing a potential drug-drug interaction.

Celiprolol double-peak occurrence and gastric motility: nonlinear mixed effects modeling of bioavailability data obtained in dogs.

Investigation of the underlying mechanism leading to inter- and intrasubject variations in the plasma concentration-time profiles of drugs (1) can considerably benefit rational drug therapy. The significant effect of gastric emptying on the rate and extent of celiprolol absorption and its role with respect to double-peak formation was demonstrated in the present study. In four dogs racemic celiprolol was dosed perorally in a crossover design during four different phases of the fasted-state gastric cycle and gastric motility was recorded simultaneously using a manometric measurement system. Intravenous doses were also given to obtain disposition and bioavailability parameters. The blood samples were assayed by a stereoselective HPLC method (2). The time to onset of the active phase of the gastric cycle showed an excellent correlation with the time to celiprolol peak concentration. Furthermore, bioavailability was increased when celiprolol was administered during the active phase. Double peaks were observed when the first active phase was relatively short, suggesting that a portion of the drug remained in the stomach until the next active phase. Population pharmacokinetic modeling of the data with a two-compartment open model with two lag times incorporating the motility data confirmed the effect of time to gastric emptying on the variability of the oral pharmacokinetics of celiprolol. The fasted-state motility phases determine the rate and extent of celiprolol absorption and influence the occurrence of double peaks. Peak plasma levels of celiprolol exhibit less variability if lag times, and therefore gastric emptying times, are taken into consideration.