Improving awareness of kidney function through electronic urine output monitoring: a comparative study.

BACKGROUND: The current classification for acute kidney injury (AKI) according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria integrates both serum creatinine (SCr) and urine output (UO). Most reports on AKI claim to use KDIGO guidelines but fail to include the UO criterion. It has been shown that patients who had intensive UO monitoring, with or without AKI, had significantly less cumulative fluid volume and fluid overload, reduced vasopressor use, and improved 30-day mortality. We examined whether real-time monitoring of this simple, sensitive, and easy-to-use biomarker in the ICU led to more appropriate intervention by healthcare providers and better outcomes.  METHODS: RenalSense Clarity RMS Consoles were installed in the General ICU at the Hadassah Medical Center, Israel, from December 2019 to November 2020. The Clarity RMS system continuously and electronically monitors UO in real-time. 100 patients were randomly selected from this period as the study group (UOelec) and compared to a matched control group (UOmanual) from the same period two years earlier. To test whether there was an association between oliguric hours and fluid treatment in each group, the correlation was calculated and analyzed for each of the different UO monitoring methods. RESULTS: Therapeutic intervention: The correlation of the sum of all oliguric hours on Day 1 and 2 with the sum of any therapeutic intervention (fluid bolus or furosemide) showed a significant correlation for the study group UOelec (P = 0.017). The matched control group UOmanual showed no such correlation (P = 0.932). Length of Stay (LOS): Median LOS [IQR] in the ICU of UOelec versus UOmanual was 69.46 [44.7, 125.9] hours and 116.5 [62.46, 281.3] hours, respectively (P = 0.0002). CONCLUSIONS: The results of our study strongly suggest that ICU patients had more meaningful and better medical intervention, and improved outcomes, with electronic UO monitoring than with manual monitoring.

Early identification of acute kidney injury in the ICU with real-time urine output monitoring: a clinical investigation.

BACKGROUND: KDIGO (Kidney Disease: Improving Global Outcomes) provides two sets of criteria to identify and classify acute kidney injury (AKI): serum creatinine (SCr) and urine output (UO). Inconsistencies in the application of KDIGO UO criteria, as well as collecting and classifying UO data, have prevented an accurate assessment of the role this easily available biomarker can play in the early identification of AKI. STUDY GOAL: To assess and compare the performance of the two KDIGO criteria (SCr and UO) for identification of AKI in the intensive care unit (ICU) by comparing the standard SCr criteria to consistent, real-time, consecutive, electronic urine output measurements. METHODS: Ninety five catheterized patients in the General ICU (GICU) of Hadassah Medical Center, Israel, were connected to the RenalSense™ Clarity RMS™ device to automatically monitor UO electronically (UOelec). UOelec and SCr were recorded for 24-48 h and up to 1 week, respectively, after ICU admission. RESULTS: Real-time consecutive UO measurements identified significantly more AKI patients than SCr in the patient population, 57.9% (N = 55) versus 26.4% (N = 25), respectively (P < 0.0001). In 20 patients that had AKI according to both criteria, time to AKI identification was significantly earlier using the UOelec criteria as compared to the SCr criteria (P < 0.0001). Among this population, the median (interquartile range (IQR)) identification time of AKI UOelec was 12.75 (8.75, 26.25) hours from ICU admission versus 39.06 (25.8, 108.64) hours for AKI SCr. CONCLUSION: Application of KDIGO criteria for AKI using continuous electronic monitoring of UO identifies more AKI patients, and identifies them earlier, than using the SCr criteria alone. This can enable the clinician to set protocol goals for earlier intervention for the prevention or treatment of AKI.

Use of tidal breathing curves for evaluating expiratory airway obstruction in infants.

OBJECTIVE: To evaluate tidal breathing (TB) flow-volume and flow-time curves for identification of expiratory airway obstruction in infants. METHODS: Pulmonary function tests were analyzed retrospectively in 156 infants aged 3-24 months with persistent or recurrent respiratory complaints. Parameters derived from TB curves were compared to maximal expiratory flow at functional residual capacity ( V˙ maxFRC) measured by rapid thoracoabdominal compression technique. Analyzed parameters were: inspiratory time (tI), expiratory time (tE), tidal volume, peak tidal expiratory flow (PTEF), time to peak tidal expiratory flow (tPTEF), expiratory flow when 50% and 25% of tidal volume remains in the lungs (FEF50, FEF25, respectively), and the ratios tPTEF/tE, tI/tE, FEF50/PTEF, and FEF25/PTEF. Statistical comparisons between flow indices and TB parameters were performed using mean squared error and Pearson's sample correlation coefficient. The study population was also divided into two groups based on severity of expiratory obstruction (above or below z-score for V˙ maxFRC of -2) to generate receiver operating characteristic (ROC) curves and calculate discriminatory values between the groups. RESULTS: TB parameters that were best correlated to V˙ maxFRC were: tPTEF/tE, FEF50/PTEF, and FEF25/PTEF, with r = 0.61, 0.67, 0.65, respectively (p < 0.0001 for all). ROC curves for FEF50/PTEF, FEF25/PTEF and tPTEF/tE showed areas under the curve of 0.813, 0.797, and 0.796, respectively. Cutoff value z-scores of -0.35, -0.34, and -0.43 for these three parameters, respectively, showed an 86% negative predictive value for severe airway obstructions. CONCLUSION: TB curves can assist in ruling out severe expiratory airway obstruction in infants.

Bronchodilator responsiveness in wheezy infants predicts continued early childhood respiratory morbidity.

OBJECTIVE: Spirometry including bronchodilator responsiveness is considered routine in the workup of asthma in older children. However, in wheezy infants the existence of bronchodilator responsiveness and its prognostic significance remain unclear. METHODS: Infants (< 2 years) with chronic or recurrent wheezing or coughing were evaluated by infant pulmonary function testing (PFT). Maximal expiratory flow at the point of functional residual capacity (V̇maxFRC) was measured before and 20 minutes after salbutamol administration. Only infants with an obstructive profile (V̇maxFRC < 80% predicted) were included. The infants were divided into two groups with regard to whether or not a response to salbutamol was observed on PFT. A response was defined as a mean V̇maxFRC after salbutamol administration exceeding the upper confidence interval limit of individual pre-bronchodilator V̇maxFRC measurements. Follow-up data was gathered after a mean of 2 years. MEASUREMENTS AND MAIN RESULTS: Sixty infants were included in the study of which 32 (53%) demonstrated responsiveness to bronchodilators. The infants in the responsive group had a significantly higher frequency of physician visits for wheezing than the non-responders (3.0 mean visits/yr vs. 1.5 respectively, P = 0.03), and had a higher likelihood of having received asthma medication in the last year of the follow-up period (84% vs. 50% respectively, RR: 1.68[1.10-2.56]). At the end of the follow-up period, more parents in the responsive group reported continued respiratory disease (71% vs. 22%, RR:3.21[1.30-7.95]). CONCLUSIONS: Bronchodilator responsiveness can be demonstrated by infant PFT in infants with recurrent wheezing and can predict increased respiratory morbidity until 3 years of age.

Infant pulmonary function testing in chronic pneumonitis of infancy due to surfactant protein C mutation.

Pulmonary function testing is a vital tool in evaluation and management of adult ILD patients and is rarely overlooked during workup. However, there is paucity of data regarding its usefulness in management of infants with suspected interstitial lung disease. In this paper, we present the contribution of infant pulmonary function testing (iPFT) to the management of two infants with biopsy confirmed chronic pneumonitis of infancy due to surfactant protein C mutation. We have productively and safely used serial iPFT for decision making both during diagnosis and follow-up of these infants.