Urinary creatinine excretion is used as a marker of completeness of timed urine collections, which are a keystone of several metabolic evaluations in clinical investigations and epidemiological surveys. The current reference values for 24-hour urinary creatinine excretion rely on observations performed in the 1960s and 1970s in relatively small and mostly selected groups, and may thus poorly fit to the present-day general European population. The aim of this study was to establish and validate anthropometry-based age- and sex-specific reference values of the 24-hour urinary creatinine excretion on adult populations with preserved renal function. We used data from two independent Swiss cross-sectional population-based studies with standardised 24-hour urinary collection and measured anthropometric variables. Only data from adults of European descent, with estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2 and reported completeness of the urinary collection were retained. A linear regression model was developed to predict centiles of the 24-hour urinary creatinine excretion in 1,137 participants from the Swiss Survey on Salt and validated in 994 participants from the Swiss Kidney Project on Genes in Hypertension. The mean urinary creatinine excretion was 193 ± 41 μmol/kg/24 hours in men and 151 ± 38 μmol/kg/24 hours in women in the Swiss Survey on Salt. The values were inversely correlated with age and body mass index (BMI). Based on current reference values (177 to 221 μmol/kg/24 hours in men and 133 to 177 μmol/kg/24 hours in women), 56% of the urinary collections in the whole population and 67% in people >60 years old would have been considered as inaccurate. A linear regression model with sex, BMI and age as predictor variables was found to provide the best prediction of the observed values and showed a good fit when applied to the validation population. We propose a validated prediction equation for 24-hour urinary creatinine excretion in the general European population, based on readily available variables such as age, sex and BMI, and a few derived normograms to ease its clinical application. This should help healthcare providers to interpret the completeness of a 24-hour urine collection in daily clinical practice and in epidemiological population studies.

A concentrate for bicarbonate haemodialysis acidified with citrate instead of acetate has been marketed in recent years. The small amount of citrate used (one-fifth of the concentration adopted in regional anticoagulation) protects against intradialyser clotting while minimally affecting the calcium concentration. The aim of this study was to compare the impact of citrate- and acetate-based dialysates on systemic haemodynamics, coagulation, acid-base status, calcium balance and dialysis efficiency.

Background. The bicarbonate concentration in dialysis fluids for intermittent haemodialysis usually is between 32 and 35 mmol/l. The severity of chronic metabolic acidosis secondary to end-stage renal failure is very variable, however, so that in some patients pre-dialysis acidosis is overcorrected. This study aimed to analyse haemodynamic tolerances to metabolic alkalosis during intermittent haemodialysis. Methods. In this randomized controlled trial with a single blind, cross-over design, we used dialysis liquids with two different bicarbonate concentrations, 32 (modality A) and 26 (modality B) mmol/l, and in 26 patients, 468 dialysis sessions, compared blood pressure, heart rate, incidence of hypotension and the frequency of corrections required with saline or hypertonic glucose infusions. Results. The results of intradialytic haemodynamic monitoring for modalities A and B, respectively, were: lowest systolic blood pressure 120.8±20.8 vs 124.3±20.6 mmHg (P < 0.01); mean systolic blood pressure 138.5±23.8 vs 144.6±24.8 mmHg (P < 0.001); and highest heart rate 73.5±12.0 vs 75.8 ± 12.9 (NS); with modality A, patients had more dialysis sessions with hypotensive episodes (5.55 vs 1.7%, P < 0.05) and required more saline or hypertonic glucose infusions (20.9 vs 13.7% of the dialysis sessions, P < 0.05). Conclusions. Mild metabolic alkalosis resulting from standard bicarbonate haemodialysis (32 mmol/l) may induce symptomatic hypotension. While normalizing chronic metabolic acidosis is desirable, reducing bicarbonate concentrations should be considered in cases of significant alkalaemia or otherwise untreatable haemodynamic instability.

Background. In a previous study we demonstrated that mild metabolic alkalosis resulting from standard bicarbonate haemodialysis induces hypotension. In this study, we have further investigated the changes in systemic haemodynamics induced by bicarbonate and calcium, using non-invasive procedures. Methods. In a randomized controlled trial with a single-blind, crossover design, we sequentially changed the dialysate bicarbonate and calcium concentrations (between 26 and 35 mmol/l for bicarbonate and either 1.25 or 1.50 mmol/l for calcium). Twenty-one patients were enrolled for a total of 756 dialysis sessions. Systemic haemodynamics was evaluated using pulse wave analysers. Bioimpedance and BNP were used to compare the fluid status pattern. Results. The haemodynamic parameters and the pre-dialysis BNP using either a high calcium or bicarbonate concentration were as follows: systolic blood pressure (+5.6 and −4.7 mmHg; P < 0.05 for both), stroke volume (+12.3 and +5.2 ml; P < 0.05 and ns), peripheral resistances (−190 and −171 dyne s cm ⁻⁵ ; P < 0.05 for both), central augmentation index (+1.1% and −2.9%; ns and P < 0.05) and BNP (−5 and −170 ng/l; ns and P < 0.05). The need of staff intervention was similar in all modalities. Conclusions. Both high bicarbonate and calcium concentrations in the dialysate improve the haemodynamic pattern during dialysis. Bicarbonate reduces arterial stiffness and ameliorates the heart tolerance for volume overload in the interdialytic phase, whereas calcium directly increases stroke volume. The slight hypotensive effect of alkalaemia should motivate a probative reduction of bicarbonate concentration in dialysis fluid for haemodynamic reasons, only in the event of failure of classical tools to prevent intradialytic hypotension.

In this systematic review, we carried out an assessment of perioperative costs of local or regional anesthesia versus general anesthesia in the ambulatory setting. A systematic literature search was conducted to find relevant data on costs and cost-effectiveness analyses of anesthesia regimens in outpatients, regardless of the medical procedure they underwent. The hypothesis was that local or regional anesthesia has a lower economic impact on hospital costs in the outpatient setting. The primary outcome was the average total cost of anesthesia calculated on perioperative costs (drugs, staff, resources used). One-thousand-six-hundred-ninety-eight records were retrieved, and 28 articles including 27,581 patients were selected after reviewing the articles. Data on the average total costs of anesthesia and other secondary outcomes (anesthesia time, recovery time, time to home readiness, hospital stay time, complications) were retrieved. Taken together, these findings indicated that local or regional anesthesia is associated with lower average total hospital costs than general anesthesia when performed in the ambulatory setting. Reductions in operating room time and postanesthesia recovery time and a lower hospital stay time may account for this result. Despite the limitations of this systematic review, mainly the heterogeneity of the studies and the lack of cost-effectiveness analysis, the economic impact of the anesthesia regimes on healthcare costs appears to be relevant and should be further evaluated.

Blood pressure variability (BPV) is an independent cardiovascular risk factor in hypertensive patients. The best method for quantifying BPV is still an object of debate. The existence of different BPV patterns, particularly age and arterial stiffness related, is postulated. Our aims were: Cross-sectional study in 108 elderly hypertensive hospitalized patients. Each patient underwent blood pressure measurements with 5 different modalities: 24 hour BP and pulse wave velocity (PWV) monitoring (24hBPM), measurement by nurses or physicians, self-measurement and beat-to-beat monitoring. Differences between maximum and minimum values (ΔBP), averages of the absolute differences between consecutive values (ARV) and coefficients of variation (CV) were calculated. ΔBP showed the wider values’ dispersion (Δ systolic blood pressure (SBP): 66.4 ± 22.9 and Δ diastolic blood pressure [DBP]: 45.0 ± 13.5 mmHg). ARV and CV were highest with nurses’ measurements (SBP-ARV 9.2 ± 6.2; DBP-ARV 6.9 ± 5.2; SBP-CV 7.6 ± 5.3; DBP-CV 9.6 ± 5.5). The strongest correlation was found comparing physicians’ SBP measurements and 24hBPM ARVs (R2 0.23, P <.05). 24hBPM ΔSBP in a multivariate analysis was significantly associated with age (β −3.85, SE 0.83; P <.001) and PWV (β 20.29, SE 3.70; P <.001). Calcium antagonists were associated with a lower ΔSBP (β −14.6, SE 6.1, P <.05) while diuretics and alpha-blockers with a significant increase (β 14.4 SE 5.4, P <.01; β 26.9 SE 11.7, P <.05). Age, PWV, diuretics, alpha-blockers, but also measurements obtained by nurses, increase BP variability while calcium antagonists reduce it. BP profiles in elderly in-hospital patients potentially provide important information; they should, however, be interpreted cautiously.