A Reassessment of Sodium Correction Rates and Hospital Length of Stay Accounting for Admission Diagnosis.

Background: Recent studies have challenged assumptions about slow correction of severe hyponatremia and have shown that rapid correction is associated with shorter hospital length of stay. However, the confounding effect of admission diagnosis has not been fully explored. The objective of this study was to determine whether rapid correction is still associated with shorter length of stay when controlling for admission diagnosis. Methods: This retrospective cohort study is based on the Medical Information Mart for Intensive Care, including data from both MIMIC-III (2001-2012) and MIMIC-IV (2008-2019). Patients were identified who presented to the hospital with initial sodium <120 mEq/L and were categorized according to total sodium correction achieved in the first day (<6 mEq/L; 6-10 mEq/L; >10 mEq/L). Linear regression was used to assess for an association between correction rate and hospital length of stay, and to determine if this association was significant when controlling for admission diagnosis classifications based on diagnosis related groups (DRGs). Results: There were 636 patients included in this study. Median [IQR] hospital length of stay was 7 [4, 11] days. Patients had a median [IQR] initial sodium value of 117 [114, 118] mEq/L and final sodium value of 124 [119, 128] mEq/L. In a univariate linear regression, the highest rate of correction (>10 mEq/L) was associated with a shorter length of stay than a moderate rate of correction (coef. -2.363, 95% CI [-4.710, -0.017], p=0.048), but the association was not significant when controlling for admission diagnosis group (coef. -1.685, 95% CI [-3.836, 0.467], p=0.125). Conclusions: Faster sodium correction was not associated with shorter length of stay when controlling for admission diagnosis categories, suggesting that the disease state confounds this association. While some patients may be discharged earlier if sodium is corrected more rapidly, others may not benefit or may be harmed by this strategy.

Estimated GFR With Cystatin C and Creatinine in Clinical Practice: A Retrospective Cohort Study.

Rationale & Objective: Estimation of glomerular filtration rate (eGFR) and staging of chronic kidney disease (CKD) are essential to guide management. Although creatinine is routinely used, a recent national task force recommended the use of cystatin C for confirmation. The objective of this study was to examine the following parameters: (1) how cystatin C correlates with creatinine eGFR; (2) how it indicates differences in CKD staging; and (3) how it may affect kidney care delivery. Study Design: Retrospective observational cohort study. Setting & Participants: 1,783 inpatients and outpatients who had cystatin C and creatinine levels drawn within 24 hours at Brigham Health-affiliated clinical laboratories. Predictors: Serum creatinine levels, basic clinical/sociodemographic variables, and reasons for ordering cystatin C from a structured partial chart review. Analytical Approach: Univariate and multivariable linear and logistic regression. Results: Cystatin C-based eGFR was very strongly correlated with creatinine-based eGFR (Spearman correlation ρ = 0.83). Cystatin C eGFR resulted in a change to a later CKD stage in 27%, an earlier stage in 7%, and no change in 66% of patients. Black race was associated with a lower likelihood of change to a later stage (OR, 0.53; 95% CI [0.36, 0.75]; P < 0.001), whereas age (OR per year OR, 1.03; 95% CI [1.02, 1.04]; P < 0.001) and Elixhauser score (OR per point OR, 1.22; 95% CI [1.10, 1.36]; P < 0.001) were associated with a higher likelihood of change to a later stage. Limitations: Single center, no direct measurement of clearance for comparison, and inconsistent self-identification of race/ethnicity. Conclusions: Cystatin C eGFR correlates strongly with creatinine eGFR but can have a substantial effect on CKD staging. As cystatin C is adopted, clinicians must be informed on this impact.

Assessment of Racial and Ethnic Differences in Oxygen Supplementation Among Patients in the Intensive Care Unit.

Importance: Pulse oximetry (SpO2) is routinely used for transcutaneous monitoring of blood oxygenation, but it can overestimate actual oxygenation. This is more common in patients of racial and ethnic minority groups. The extent to which these discrepancies are associated with variations in treatment is not known. Objective: To determine if there are racial and ethnic disparities in supplemental oxygen administration associated with inconsistent pulse oximeter performance. Design, Setting, and Participants: This retrospective cohort study was based on the Medical Information Mart for Intensive Care (MIMIC)-IV critical care data set. Included patients were documented with a race and ethnicity as Asian, Black, Hispanic, or White and were admitted to the intensive care unit (ICU) for at least 12 hours before needing advanced respiratory support, if any. Oxygenation levels and nasal cannula flow rates for up to 5 days from ICU admission or until the time of intubation, noninvasive positive pressure ventilation, high-flow nasal cannula, or tracheostomy were analyzed. Main Outcomes and Measures: The primary outcome was time-weighted average supplemental oxygen rate. Covariates included race and ethnicity, sex, SpO2-hemoglobin oxygen saturation discrepancy, data duration, number and timing of blood gas tests on ICU days 1 to 3, partial pressure of carbon dioxide, hemoglobin level, average respiratory rate, Elixhauser comorbidity scores, and need for vasopressors or inotropes. Results: This cohort included 3069 patients (mean [SD] age, 66.9 [13.5] years; 83 were Asian, 207 were Black, 112 were Hispanic, 2667 were White). In a multivariable linear regression, Asian (coefficient, 0.602; 95% CI, 0.263 to 0.941; P = .001), Black (coefficient, 0.919; 95% CI, 0.698 to 1.140; P < .001), and Hispanic (coefficient, 0.622; 95% CI, 0.329 to 0.915; P < .001) race and ethnicity were all associated with a higher SpO2 for a given hemoglobin oxygen saturation. Asian (coefficient, -0.291; 95% CI, -0.546 to -0.035; P = .03), Black (coefficient, -0.294; 95% CI, -0.460 to -0.128; P = .001), and Hispanic (coefficient, -0.242; 95% CI, -0.463 to -0.020; P = .03) race and ethnicity were associated with lower average oxygen delivery rates. When controlling for the discrepancy between average SpO2 and average hemoglobin oxygen saturation, race and ethnicity were not associated with oxygen delivery rate. This discrepancy mediated the effect of race and ethnicity (-0.157; 95% CI, -0.250 to -0.057; P = .002). Conclusions and Relevance: In this cohort study, Asian, Black, and Hispanic patients received less supplemental oxygen than White patients, and this was associated with differences in pulse oximeter performance, which may contribute to known race and ethnicity-based disparities in care.

Life-space mobility is associated with frequency of hospitalization in adults with cystic fibrosis.

INTRODUCTION AND OBJECTIVES: The Life-Space Assessment can be used to measure a patient's level of mobility. This study evaluated the relationship between life-space mobility and frequency of hospitalization in the previous year and other clinical markers of health among adults with cystic fibrosis (CF). METHODS: The Life-Space Assessment was administered to ambulatory adults with CF in clinic or by telephone. Life-space mobility was correlated with the most recent forced expiratory volume in one second as a percent of the predicted value (FEV(1) % predicted), body mass index (BMI) and number of hospitalizations in the previous year. RESULTS: Forty-eight subjects completed the Life-Space Assessment. Subjects had a life-space score of 88 ± 26, FEV(1) % predicted of 66% ± 26% and BMI of 22.5 ± 3.3. There was a statistically significant negative linear correlation between the number of times a subject was hospitalized in the previous year and life-space mobility (P = 0.001, R(2) = 0.20). This association was independent of FEV(1) % predicted and BMI. CONCLUSION: The life-space mobility score is associated with frequency of hospitalization in adults with CF. A prospective study should be undertaken to assess the ability of the Life-Space Assessment to predict hospitalization and other outcomes in adults with CF.