Diagnosis of urinary tract infection in older persons in the emergency department: To pee or not to pee, that is the question

Doreen is a 79-year-old woman referred by her general practitioner to the ED for intravenous antibiotics for a urinary tract infection (UTI). She lives in a residential aged care facility (RACF) and staff report malodourous and cloudy urine. She denies dysuria or frequency. On examination Doreen is frail with vital signs of: temperature 37.7°C, pulse 87 bpm, blood pressure 130/70; there is no suprapubic or flank tenderness. Do you perform a dipstick test on Doreen’s urine for a suspected UTI?

Evaluating Antibiotic Sensitivity Patterns of Pseudomonas in Relation to Specimen Type in Jordanian Hospital

OBJECTIVE

To evaluate the sensitivity patterns of different antibiotics of pseudomonas in relation to specimen types.

METHODS

The quantitative retrospective study was conducted at Princess Iman Research and Laboratory Sciences Centre of Royal Medical Services, Amman, Jordan. The specimens of USS, urine, cerebral spinal fluid, and blood were collected from patients, who visited the hospital from January to September 2015. Drugs analysed included ampicillin, ceftazidime, ciprofloxacin, cefotaxime, cefoxitin, nitrofurantoin and gentamicin.

RESULTS

There were 358 samples collected. Ampicillin was found effective (p=0.002). There was a weaker correlation between amikacin and amoxicillin/clavulanic acid (r=-0.001). Similarly, nitrofurantoin was also effective (p=0.001), and the association between amikacin and ceftazidime was positive (r=0.998).

CONCLUSIONS

The selected antibiotics were only examined, concerning the sensitivity patterns as data collected from the patients was insufficient for other drugs.

Pre-analytical Factors Influence Accuracy of Urine Spot Iodine Assessment in Epidemiological Surveys

Urinary iodine concentration (UIC) is commonly used to assess iodine status of subjects in epidemiological surveys. As pre-analytical factors are an important source of measurement error and studies about this phase are scarce, our objective was to assess the influence of urine sampling conditions on UIC, i.e., whether the child ate breakfast or not, urine void rank of the day, and time span between last meal and urine collection. A nationwide, two-stage, stratified, cross-sectional study including 1560 children (6-12 years) was performed in 2012. UIC was determined by the Sandell-Kolthoff method. Pre-analytical factors were assessed from children's mothers by using a questionnaire. Association between iodine status and pre-analytical factors were adjusted for one another and socio-economic characteristics by multivariate linear and multinomial regression models (RPR: relative prevalence ratios). Skipping breakfast prior to morning urine sampling decreased UIC by 40 to 50 μg/L and the proportion of UIC < 100 μg/L was higher among children having those skipped breakfast (RPR = 3.2[1.0-10.4]). In unadjusted analyses, UIC was less among children sampled more than 5 h from their last meal. UIC decreased with rank of urine void (e.g., first vs. second, P < 0.001); also, the proportion of UIC < 100 μg/L was greater among 4th rank samples (vs. second RPR = 2.1[1.1-4.0]). Subjects' breakfast status and urine void rank should be accounted for when assessing iodine status. Providing recommendations to standardize pre-analytical factors is a key step toward improving accuracy and comparability of survey results for assessing iodine status from spot urine samples. These recommendations have to be evaluated by future research.

Measurement duration affects the calculation of whole body protein turnover kinetics but not between-day variability

BACKGROUND

Assessment of whole body protein turnover (WBPT) can provide fundamental information about protein kinetics which underpins the conservation of lean tissue. Reliability and methodology studies on the measurement of WBPT are scarce. This study aimed to assess the effects of urine collection duration (9 versus 12 h) and the reproducibility of WBPT with the end product method calculated from ammonia as the end product.

METHODS

WBPT was assessed in 21 healthy participants (11M, 10F) on 2 test days. WBPT was assessed using the end product method with a single dose of ¹⁵N glycine with ammonia as end product in a postprandial state with 9 and 12-h urine collections.

RESULTS

The CV for protein flux averaged 10% and 12% for 9 and 12-h urine collections respectively. Protein flux, synthesis and balance were significantly higher and protein breakdown significantly lower with 9-h urine collections compared to 12-h collections (P < 0.01) and there was a trend towards increasingly greater overestimation of 9-h calculated WBPT kinetics with greater overall rates of WBPT. Correlations between the 9 and 12-h values were strong (r > 0.962, P < 0.001 for all variables).

CONCLUSIONS

The reproducibility of WBPT with ammonia as the end product was similar to previously reported reproducibility of the gold standard precursor technique. The use of a 12-h urine collection is more effective to achieve full turnover of the ammonia free amino acid (AA) pool.

Storage Time and Urine Biomarker Levels in the ASSESS-AKI Study

BACKGROUND

Although stored urine samples are often used in biomarker studies focused on acute and chronic kidney disease, how storage time impacts biomarker levels is not well understood.

METHODS

866 subjects enrolled in the NIDDK-sponsored ASsessment, Serial Evaluation, and Subsequent Sequelae in Acute Kidney Injury (ASSESS-AKI) Study were included. Samples were processed under standard conditions and stored at -70°C until analyzed. Kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), and liver fatty acid binding protein (L-FABP) were measured in urine samples collected during the index hospitalization or an outpatient visit 3 months later. Mixed effects models were used to determine the effect of storage time on biomarker levels and stratified by visit.

RESULTS

Median storage was 17.8 months (25-75% IQR 10.6-23.7) for samples from the index hospitalization and 14.6 months (IQR 7.3-20.4) for outpatient samples. In the mixed effects models, the only significant association between storage time and biomarker concentration was for KIM-1 in outpatient samples, where each month of storage was associated with a 1.7% decrease (95% CI -3% to -0.3%). There was no relationship between storage time and KIM-1 levels in samples from the index hospitalization.

CONCLUSION

There was no significant impact of storage time over a median of 18 months on urine KIM-1, NGAL, IL-18 or L-FABP in hospitalized samples; a statistically significant effect towards a decrease over time was noted for KIM-1 in outpatient samples. Additional studies are needed to determine whether longer periods of storage at -70°C systematically impact levels of these analytes.

How and when nurses collect urine cultures on catheterized patients: A survey of 5 hospitals

BACKGROUND

Obtaining a specimen for urine culture is a key element in evaluating for catheter-associated urinary tract infections (CAUTIs). Evaluating nurses' knowledge regarding appropriate reasons and methods to obtain urine culture specimens are the first steps to improving practice.

METHODS

Nurses at 5 hospitals completed a 40-question survey regarding their knowledge, training, and practices of appropriate reasons for obtaining urine cultures. The survey included different scenarios of patients with urinary catheters and when they would expect to obtain urine cultures. A 12-point scoring system calculated responses regarding urine collection appropriateness.

RESULTS

There were 394 nurses who responded to the survey. Of them, 76.1% reported receiving education on CAUTI risk reduction within the last 12 months. Although 327 (83%) of all nurses surveyed reported that they never collect urine samples by draining directly from the drainage bag, only 58.4% viewed others to be fully compliant with that standard (P < .001). Nurses who considered their knowledge to be above average to excellent had similar knowledge assessment scores (out of 12 points) for triggers to obtain urine cultures (mean score, 4.9 ± 1.72) compared with those that reported average to poor knowledge (mean score, 4.64 ± 1.78; P = .15).

CONCLUSIONS

Important opportunities exist for nurses to optimize the decisions to obtain urine cultures and the process for obtaining them. Addressing nurses' knowledge and practice may lead to more appropriate use of urine cultures.

Number and frequency of albuminuria measurements in clinical trials in diabetic nephropathy

BACKGROUND AND OBJECTIVES

Albuminuria change is often used to assess drug efficacy in intervention trials in nephrology. The change is often calculated using a variable number of urine samples collected at baseline and end of treatment. Yet more albuminuria measurements usually occur. Because albuminuria shows a large day-to-day variability, this study assessed to what extent the average and the precision of the antialbuminuric drug effect varies with the number of urine collections at each visit and the number of follow-up visits.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study used data from three randomized intervention trials (Aliskiren Combined with Losartan in Type 2 Diabetes and Nephropathy, Selective Vitamin D Receptor Activation for Albuminuria Lowering, and Residual Albuminuria Lowering with Endothelin Antagonist Atrasentan) including patients with type 2 diabetes and macroalbuminuria. Albuminuria-lowering drug effects were estimated from one, two, or three urine collections at consecutive days before each study visit and reported as albuminuria change from baseline to end of treatment or the change over time considering an average of all follow-up albuminuria measurements.

RESULTS

Increasing the number of urine collections for an albuminuria measurement at baseline and end of treatment or using all study visits during follow-up did not alter the average drug effect. The precision of the drug effect increased (decreased SEM) when the number of study visits and the number of urine collections per visit were increased. Using all albuminuria measurements at all study visits led to a 4- to 6-fold reduction in sample size to detect a 30% albuminuria-lowering treatment effect with 80% power compared with using baseline and end-of-treatment albuminuria measurements alone.

CONCLUSIONS

Increasing the number of urine collections per study visit and the number of visits over time does not change the average drug effect estimate but markedly increases the precision, thereby enhancing statistical power. Thus, clinical trial designs in diabetic nephropathy using albuminuria as an end point can be significantly improved, leading to smaller sample sizes and less complex trials.

Intraindividual variation in urinary iodine concentrations: effect of adjustment on population distribution using two and three repeated spot urine collections

OBJECTIVES

To determine the effect of adjustment for intraindividual variation on estimations of urinary iodine concentrations (UIC), prevalence of iodine deficiency and population distribution of iodine status.

SETTING

Community-dwelling older adults from New South Wales, Australia.

PARTICIPANTS

84 healthy men and women aged 60-95 years were recruited prior to introduction of the mandatory iodine fortification programme.

PRIMARY AND SECONDARY OUTCOME MEASURES

UIC data were collected from three spot urine samples, each 1 week apart. Repeated measures analysis of variance were determined between-person (sb) and total (sobs) SDs. Adjusted UIC values were calculated as ((person's UIC-group mean)×(sb/sobs))+group mean, and a corrected UIC distribution was calculated.

RESULTS

The sb/sobs for using three samples and two samples were 0.83 and 0.79, respectively. Following adjustment for intraindividual variation, the proportion with UIC <50 μg/L reduced from 33% to 19%, while the proportion with UIC ≥100 μg/L changed from 21% to 17%. The 95th centile for UIC decreased from 176 to 136 μg/L. Adjustment by taking averages yielded a lesser degree of contraction in the distribution than the analysis of variance method.

CONCLUSIONS

The addition of information about intraindividual variability has potential for increasing the interpretability of UIC data collected to monitor the iodine status of a population.