Trends in Therapy and Outcomes Associated With Respiratory Failure in Patients Admitted to the Cardiac Intensive Care Unit

PURPOSE

To describe the epidemiology, outcomes, and temporal trends of respiratory failure in the cardiac intensive care unit (CICU).

MATERIALS AND METHODS

Retrospective cohort analysis of 2,986 unique Mayo Clinic CICU patients from 2007 to 2018 with respiratory failure. Temporal trends were analyzed, along with hospital and 1-year mortality. Multivariable logistic regression was used to determine adjusted hospital mortality trends.

RESULTS

The prevalence of respiratory failure in the CICU increased from 15% to 38% during the study period (P < 0.001 for trend). Among patients with respiratory failure, the utilization of invasive ventilation decreased and noninvasive ventilation modalities increased over time. Hospital mortality and 1-year mortality were 24% and 54%, respectively, with variation according to the type of respiratory support (highest among patients receiving invasive ventilation alone: 35% and 46%, respectively). Hospital mortality was highest among patients with concomitant cardiac arrest and/or shock (52% for patients with both). Hospital mortality decreased in the overall population from 35% to 25% (P < 0.001 for trend), but was unchanged among patients receiving positive-pressure ventilation.

CONCLUSIONS

The prevalence of respiratory failure in CICU more than doubled during the last decade. The use of noninvasive respiratory support increased, while overall mortality declined over time. Cardiac arrest and shock accounted for the majority of deaths. Further research is needed to optimize the outcomes of high-risk CICU patients with respiratory failure.

Derivation and Validation of an Automated Search Strategy to Retrospectively Identify Acute Respiratory Distress Patients Per Berlin Definition

Purpose: Acute respiratory distress syndrome (ARDS) is common in critically ill patients and linked with serious consequences. A manual chart review for ARDS diagnosis could be laborious and time-consuming. We developed an automated search strategy to retrospectively identify ARDS patients using the Berlin definition to allow for timely and accurate ARDS detection.

Methods: The automated search strategy was created through sequential steps, with keywords applied to an institutional electronic medical records (EMRs) database. We included all adult patients admitted to the intensive care unit (ICU) at the Mayo Clinic (Rochester, MN) from January 1, 2009 to December 31, 2017. We selected 100 patients at random to be divided into two derivation cohorts and identified 50 patients at random for the validation cohort. The sensitivity and specificity of the automated search strategy were compared with a manual medical record review (gold standard) for data extraction of ARDS patients per Berlin definition.

Results: On the first derivation cohort, the automated search strategy achieved a sensitivity of 91.3%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 93.1%. On the second derivation cohort, it reached the sensitivity of 90.9%, specificity of 100%, PPV of 100%, and NPV of 93.3%. The strategy performance in the validation cohort had a sensitivity of 94.4%, specificity of 96.9%, PPV of 94.4%, and NPV of 96.9%.

Conclusions: This automated search strategy for ARDS with the Berlin definition is reliable and accurate, and can serve as an efficient alternative to time-consuming manual data review.

A Descriptive Study of Late Intensive Care Unit Admissions After Adult Solitary Kidney Transplantation

OBJECTIVE

Kidney transplant recipients are at lifetime risk of requiring high acuity care. In the current study, we aimed to assess the reasons for delayed (> 30 days) intensive care unit (ICU) admissions post-transplant and causes of ICU-related mortality.

METHODS

This is a retrospective study of a cohort of adult kidney transplant patients from January 1, 2007, through December 31, 2016, who required ICU admission after 30 days of transplantation. The admissions were divided into 3 groups based on their timeline between transplantation and ICU admission: 1. group 1 from 30 days to 6 months, 2. group 2 between 6-24 months, and 3. group 3 after 2 years. All admissions were categorized according to the primary organ system involved.

RESULTS

A total of 285 (group 1: 50, group 2: 89, group 3: 146) patients required 404 ICU admissions (group 1: 57, group 2: 108, group 3: 239). Overall, cardiovascular system-related admissions (29.9%, 18.5%, 15.9%), infections (19.3%, 25.9%, 27.2%), and respiratory-related admissions (12.3%, 8.3%, 8.8%) were main causes in all 3 groups. A total of 24 (8.4%) patients died in the ICU. Most of the deaths occurred in men (79.2%), infection-related admissions (45.8%), and individuals with a functioning allograft (66.7%). Infections (45.8%) were the main causes of ICU-related mortality. Median time from transplantation to death was 2.3 years (interquartile range: 1.2-4.6).

CONCLUSION

Kidney transplant patients continue to be at risk of requiring high acuity care long after transplantation. Most of these admissions are related to cardiopulmonary system involvement or infections. Overall, infections were the leading cause of ICU-related mortality.

In adults with hypertension, more- vs. less-intensive BP-lowering treatment reduces orthostatic hypotension

Juraschek SP, Hu JR, Cluett JL, et al. Effects of intensive blood pressure treatment on orthostatic hypotension: a systematic review and individual participant-based meta-analysis. Ann Intern Med. 2020. [Epub ahead of print.] 32909814.

New-onset atrial fibrillation in patients with acute kidney injury on continuous renal replacement therapy

PURPOSE

The mortality of critically ill patients with acute kidney injury (AKI) who require continuous renal replacement therapy (CRRT) remains high. We assessed the incidence and predictors of new-onset atrial fibrillation (NOAF) in this population and its impact on outcomes.

MATERIALS AND METHODS

This is a retrospective cohort study of adult intensive care units (ICU) patients who had AKI and received CRRT from December 2006 through November 2015 in a tertiary academic medical center. Cox proportional hazard model was used to evaluate the impact of NOAF on overall mortality.

RESULTS

Out of 1398 screened patients, NOAF occurred in 193 (14%) cases. NOAF occurring on CRRT was independently associated with an increased hazard of death at follow-up (HR: 1.26; 95% CI: 1.03-1.56), compared to the group who did not have NOAF. In the multivariable analysis using time-dependent covariates, higher potassium (HR 1.24, 95%CI: 1.01-1.54) and bicarbonate (HR 0.95, 95%CI: 0.92-0.98) levels were associated with increased and decreased risk of NOAF on CRRT, respectively.

CONCLUSIONS

NOAF in critically ill patients with AKI receiving CRRT is common and carries an unfavorable prognosis. Prospective studies are required to elucidate modifiable risk factors for NOAF occurring on CRRT.

Prediction of Vancomycin Levels Using Cystatin C in Overweight and Obese Patients: a Retrospective Cohort Study of Hospitalized Patients

The use of the kidney function biomarker cystatin C (cysC) can improve the accuracy of vancomycin dosing for target trough attainment in nonobese patients. It is unknown whether cysC can also improve vancomycin target trough attainment in overweight and obese patients. We conducted a retrospective observational study of overweight or obese hospitalized adults with stable renal function administered intravenous vancomycin between January 2011 and July 2019. Linear regression models were used to predict initial steady-state vancomycin troughs using several factors, including various cysC- and serum creatinine (SCr)-based estimates of kidney function. We compared the predicted proportion of patients within the target trough range (10 to 20 mg/liter) using the derived models to that observed from usual care. Of the 200 included patients, the mean trough level was 15 ± 6.3 mg/liter. The optimal model to predict the initial trough included both cysC and SCr (R2 = 0.48) rather than either biomarker alone. This model predicted that 79% (95% confidence interval [CI], 73% to 85%) of troughs could be between 10 and 20 mg/liter compared to the 62% observed in clinical practice (P < 0.001), a 1.3-fold increase. This study is the first to examine the role of cysC in predicting vancomycin levels in an exclusively overweight or obese population. While dosing models based on cysC appear promising in this setting, prospective validation is needed.

Clinician perspectives on inpatient cystatin C utilization: A qualitative case study at Mayo Clinic

Introduction

Serum creatinine (SCr) testing has been the mainstay of kidney function assessment for decades despite known limitations. Cystatin C (CysC) is an alternative biomarker that is generally less affected than SCr by pertinent non-renal factors in hospitalized patients, such as muscle mass. Despite its potential advantages, the adoption of CysC for inpatient care is not widespread. At one hospital with CysC testing, we demonstrated a significant rise in non-protocolized use over the last decade. This study uses qualitative methods to provide the first report of how clinicians understand, approach, and apply CysC testing in inpatient care.

Methods

Fifteen clinicians from various disciplines were interviewed about their experience with inpatient CysC testing. The semi-structured interviews were audio-recorded, transcribed verbatim, and analyzed thematically using a phenomenological approach.

Results

Knowledge and confidence with CysC varied greatly. Clinicians reported first learning about the test from colleagues on consulting services or multidisciplinary teams. The majority believed CysC to provide a more accurate measure of kidney function than SCr. Common scenarios for CysC ordering included medication dosing, evaluation of acute kidney injury, and a thorough evaluation of kidney function in patients with risk factors for an altered SCr. Facilitators for ordering CysC included the availability of rapid results turnaround and the automated calculation of glomerular filtration rate based on the biomarker. Barriers to use included a lack of education about CysC, and the absence of an institutional protocol for use.

Discussion

Clinicians at our site decided independent of institutional guidance whether and when CysC added value to patient care. While the majority of study participants indicated advantages to rapid turnaround CysC testing, its use depended not just on the features of the specific case but on clinician familiarity and personal preference. Findings from this research can guide the implementation and expansion of CysC testing.

Systemic Inflammatory Response Syndrome Is Associated With Increased Mortality Across the Spectrum of Shock Severity in Cardiac Intensive Care Patients

BACKGROUND

The systemic inflammatory response syndrome (SIRS) frequently occurs in patients with cardiogenic shock and may aggravate shock severity and organ failure. We sought to determine the association of SIRS with illness severity and survival across the spectrum of shock severity in cardiac intensive care unit (CICU) patients.

METHODS

We retrospectively analyzed 8995 unique patients admitted to the Mayo Clinic CICU between 2007 and 2015. Patients with ≥2/4 SIRS criteria based on admission laboratory and vital sign data were considered to have SIRS. Patients were stratified by the 2019 Society for Cardiovascular Angiography and Interventions (SCAI) shock stages using admission data. The association between SIRS and mortality was evaluated across SCAI shock stage using logistic regression and Cox proportional-hazards models for hospital and 1-year mortality, respectively.

RESULTS

The study population had a mean age of 67.5±15.2 years, including 37.2% women. SIRS was present in 33.9% of patients upon CICU admission and was more prevalent in advanced SCAI shock stages. Patients with SIRS had higher illness severity, worse shock, and more organ failure, with an increased risk of mortality during hospitalization (16.8% versus 3.8%; adjusted odds ratio, 2.1 [95% CI, 1.7-2.5]; P<0.001) and at 1 year (adjusted hazard ratio, 1.4 [95% CI, 1.3-1.6]; P<0.001). After multivariable adjustment, SIRS was associated with higher hospital and 1-year mortality among patients in SCAI shock stages A through D (all P<0.01) but not SCAI shock stage E.

CONCLUSIONS

One-third of CICU patients meet clinical criteria for SIRS at the time of admission, and these patients have higher illness severity and worse outcomes across the spectrum of SCAI shock stages. The presence of SIRS identified CICU patients at increased risk of short-term and long-term mortality. Further study is needed to determine whether systemic inflammation truly drives SIRS in this population and whether patients with SIRS respond differently to supportive therapies for shock.

Association of serum magnesium level change with in-hospital mortality

The objective of this study was to assess the association of in-hospital mortality risk based on change in serum magnesium levels in hospitalised patients. All adult patients admitted to our hospital from years 2009 to 2013 with at least two serum magnesium measurements during hospitalisation were included. Serum magnesium change, defined as the absolute difference between the highest and lowest serum magnesium, was categorised into six groups: 0-0.2, 0.3-0.4, 0.5-0.6, 0.7-0.8, 0.9-1.0, ≥1.1 mg/dL. In-hospital mortality was the outcome of interest. Logistic regression was used to assess the association between serum magnesium change and in-hospital mortality, using serum magnesium change of 0.0-0.2 mg/dL as the reference group. A total of 42 141 patients, with the median serum magnesium change during hospital stay of 0.3 (IQR 0.2-0.6) mg/dL, were studied. In-hospital mortality based on serum magnesium change of 0-0.2, 0.3-0.4, 0.5-0.6, 0.7-0.8, 0.9-1.0, ≥1.1 mg/dL was 1.3%, 2.3%, 3.1%, 5.0%, 6.5%, and 8.8%, respectively (p<0.001). After adjustment for potential confounders, increased serum magnesium change was significantly associated with higher in-hospital mortality with adjusted OR of 1.39 (95% 1.14-1.69) in serum magnesium change of 0.3-0.4, 1.48 (95% CI 1.21 to 1.81) in 0.5-0.6, 1.89 (95% CI 1.53 to 2.34) in 0.7-0.8, 1.85 (95% CI 1.45 to 2.37) in 0.9-1.0 and 1.89 (95% CI 1.48 to 2.41) in ≥1.1 mg/dL when compared with serum magnesium change group of 0-0.2 mg/dL. Increased in-hospital mortality was associated with both downward and upward trends of serum magnesium change during hospitalisation. The greater extent of change in serum magnesium levels was progressively associated with increased in-hospital mortality.

Change in right ventricular systolic function after continuous renal replacement therapy initiation and renal recovery

OBJECTIVE

To describe the associations between right ventricular (RV) function and outcomes of patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT).

METHODS

This is a retrospective study, conducted 2006-2015 at an academic hospital in USA. We included patients with AKI requiring CRRT who had paired echocardiograms within 2 weeks before and after CRRT initiation. We defined improvement in RV systolic function as 2-point improvement on the semiquantitative scale.

RESULTS

The cohort included 201 patients. The mean(±SD) age was 59(±16) years with 83(41%) female. The median time of the pre and post echocardiograms relative to CRRT initiation were - 1 day (IQR-3;0) prior to and 3 days (IQR1;7) after CRRT initiation. Thirty-one (15%) patients showed an improvement in their RV function. Using a multivariable logistic regression model, improvement in RV systolic function was associated with lower odds of major adverse kidney events (composite of mortality, need for dialysis or persistently elevated serum creatinine) at 90 days with odds ratio (OR) of 0.37(95%CI:0.17-0.84, p.016). Positive cumulative fluid balance was associated with lower odds of improvement in RV function (OR 0.95 per 1-l increase, p 0.045).

CONCLUSION

Serial assessment of RV function among patients with AKI requiring CRRT could provide prognostic value.

Impact of serum phosphate changes on in-hospital mortality

Background

Fluctuations in serum phosphate levels increased mortality in end-stage renal disease patients. However, the impacts of serum phosphate changes in hospitalized patients remain unclear. This study aimed to test the hypothesis that serum phosphate changes during hospitalization were associated with in-hospital mortality.

Methods

We included all adult hospitalized patients from January 2009 to December 2013 that had at least two serum phosphate measurements during their hospitalization. We categorized in-hospital serum phosphate changes, defined as the absolute difference between the maximum and minimum serum phosphate, into 5 groups: 0–0.6, 0.7–1.3, 1.4–2.0, 2.1–2.7, ≥2.8 mg/dL. Using serum phosphate change group of 0–0.6 mg/dL as the reference group, the adjusted odds ratio of in-hospital mortality for various serum phosphate change groups was obtained by multivariable logistic regression analysis.

Results

A total of 28,149 patients were studied. The in-hospital mortality in patients with serum phosphate changes of 0–0.6, 0.7–1.3, 1.4–2.0, 2.1–2.7, ≥2.8 mg/dL was 1.5, 2.0, 3.1, 4.4, and 10.7%, respectively (p < 0.001). When adjusted for confounding factors, larger serum phosphate changes were associated with progressively increased in-hospital mortality with odds ratios of 1.35 (95% 1.04–1.74) in 0.7–1.3 mg/dL, 1.98 (95% CI 1.53–2.55) in 1.4–2.0 mg/dL, 2.68 (95% CI 2.07–3.48) in 2.1–2.7 mg/dL, and 5.04 (95% CI 3.94–6.45) in ≥2.8 mg/dL compared to serum phosphate change group of 0–0.6 mg/dL. A similar result was noted when we further adjusted for either the admission or mean serum phosphate during hospitalization.

Conclusion

Greater serum phosphate changes were progressively associated with increased in-hospital mortality.

The prognostic importance of serum sodium levels at hospital discharge and one-year mortality among hospitalized patients

BACKGROUND

The optimal range of serum sodium at hospital discharge is unclear. Our objective was to assess the one-year mortality based on discharge serum sodium in hospitalized patients.

METHODS

We analyzed a cohort of hospitalized adult patients between 2011 and 2013 who survived hospital admission at a tertiary referral hospital. We categorized discharge serum sodium into five groups; ≤132, 133-137, 138-142, 143-147, and ≥148 mEq/L. We assessed one-year mortality risk after hospital discharge based on discharge serum sodium, using discharge sodium of 138-142 mEq/L as the reference group.

RESULTS

Of 55 901 eligible patients, 4.9%, 29.8%, 56.1%, 8.9%, 0.3% had serum sodium of ≤132, 133-137, 138-142, 143-147, and ≥148 mEq/L, respectively. We observed a U-shaped association between discharge serum sodium and one-year mortality, with nadir mortality in discharge serum sodium of 138-142 mEq/L. When adjusting for potential confounders, including admission serum sodium, one-year mortality was significantly higher in both discharge serum sodium ≤137 and ≥143 mEq/L, compared with discharge serum sodium of 138-142 mEq/L. The mortality risk was the most prominent in elevated discharge serum sodium of ≥148 mEq/L (HR 3.86; 95% CI 3.05-4.88), exceeding the risk associated with low discharge serum sodium of ≤132 mEq/L (HR 1.43; 95% CI 1.30-1.57).

CONCLUSION

The optimal range of serum sodium at discharge was 138-142 mEq/L. Both hypernatremia and hyponatremia at discharge were associated with higher one-year mortality. The impact on higher one-year mortality was more prominent in hypernatremia than hyponatremia.

Quality of care after AKI development in the hospital: Consensus from the 22nd Acute Disease Quality Initiative (ADQI) conference

BACKGROUND

Acute kidney injury (AKI) is independently associated with increased morbidity and mortality. Quality improvement has been identified as an important goal in the care of patients with AKI. Different settings can be targeted to improve AKI care, broadly classified these include the inpatient and outpatient environments. In this paper, we will emphasize quality indicators associated with the management and secondary prevention of AKI in hospitalized patients to limit the severity, duration, and complications.

METHODS

During the 22nd Acute Disease Quality Initiative (ADQI) consensus conference, a multidisciplinary group of experts discussed the evidence and used a modified Delphi process to achieve consensus on recommendations for AKI-related quality indicators (QIs) and care processes to improve patient outcomes. The management and secondary prevention of AKI in hospitalized patients were discussed, and recommendations were summarized.

RESULTS

The first step in optimizing the quality of AKI management is the determination of baseline performance. Data regarding each institution's/center's performance can provide a reference point from which to benchmark quality efforts. Quality program initiatives should prioritize achievable goals likely to have the highest impact according to the setting and context. Key AKI quality metrics should include improvement in timely recognition, appropriate diagnostic workup, and implementation of known interventions that limit progression and severity, facilitating recovery, and mitigating AKI-associated complications. We propose the Recognition-Action-Results framework to plan, measure, and report the progress toward improving AKI management quality.

CONCLUSIONS

These recommendations identified and outlined an approach to define and evaluate the quality of AKI management in hospitalized patients.

Predicting acute kidney injury in critically ill patients using comorbid conditions utilizing machine learning

Background

Acute kidney injury (AKI) carries a poor prognosis. Its incidence is increasing in the intensive care unit (ICU). Our purpose in this study is to develop and externally validate a model for predicting AKI in the ICU using patient data present prior to ICU admission.

Methods

We used data of 98 472 adult ICU admissions at Mayo Clinic between 1 January 2005 and 31 December 2017 and 51 801 encounters from Medical Information Mart for Intensive Care III (MIMIC-III) cohort. A gradient-boosting model was trained on 80% of the Mayo Clinic cohort using a set of features to predict AKI acquired in the ICU.

Results

AKI was identified in 39 307 (39.9%) encounters in the Mayo Clinic cohort. Patients who developed AKI in the ICU were older and had higher ICU and in-hospital mortality compared to patients without AKI. A 30-feature model yielded an area under the receiver operating curve of 0.690 [95% confidence interval (CI) 0.682–0.697] in the Mayo Clinic cohort set and 0.656 (95% CI 0.648–0.664) in the MIMIC-III cohort.

Conclusions

Using machine learning, AKI among ICU patients can be predicted using information available prior to admission. This model is independent of ICU information, making it valuable for stratifying patients at admission.

Incidence and mortality of acute kidney injury in patients undergoing hematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

While acute kidney injury (AKI) is commonly reported following hematopoietic stem cell transplant (HCT), the incidence and impact of AKI on mortality among patients undergoing HCT are not well described. We conducted this systematic review to assess the incidence and impact of AKI on mortality risk among patients undergoing HCT.

METHODS

Ovid MEDLINE, EMBASE and the Cochrane Databases were searched from database inceptions through August 2019 to identify studies assessing the incidence of AKI and mortality risk among adult patients who developed AKI following HCT. Random-effects and generic inverse variance method of DerSimonian-Laird were used to combine the effect estimates obtained from individual studies.

RESULTS

We included 36 cohort studies with a total of 5144 patients undergoing HCT. Overall, the pooled estimated incidence of AKI and severe AKI (AKI Stage III) were 55.1% (95% confidence interval (CI) 46.6-63.3%) and 8.3% (95% CI 6.0-11.4%), respectively. The pooled estimated incidence of AKI using contemporary AKI definitions (RIFLE, AKIN and KDIGO criteria) was 49.8% (95% CI 41.6-58.1%). There was no significant correlation between study year and the incidence of AKI (P = 0.12) or severe AKI (P = 0.97). The pooled odds ratios of 3-month mortality and 3-year mortality among patients undergoing HCT with AKI were 3.05 (95% CI 2.07-4.49) and 2.23 (95% CI 1.06-4.73), respectively.

CONCLUSION

The incidence of AKI among patients who undergo HCT remains high, and it has not changed over the years despite advances in medicine. AKI after HCT is associated with increased short- and long-term mortality.

Angiotensin II Infusion for Shock: A Multicenter Study of Postmarketing Use

BACKGROUND

Vasodilatory shock refractory to catecholamine vasopressors and arginine vasopressin is highly morbid and responsible for significant mortality. Synthetic angiotensin II is a potent vasoconstrictor that may be suitable for use in these patients.

RESEARCH QUESTION

What is the safety and effectiveness of angiotensin II and what variables are associated with a favorable hemodynamic response?

STUDY DESIGN AND METHODS

We performed a multicenter, retrospective study at five tertiary medical centers in the United States. The primary end point of hemodynamic responsiveness to angiotensin II was defined as attainment of mean arterial pressure (MAP) of ≥ 65 mm Hg with a stable or reduced total vasopressor dosage 3 h after drug initiation.

RESULTS

Of 270 included patients, 181 (67%) demonstrated hemodynamic responsiveness to angiotensin II. Responders showed a greater increase in MAP (+10.3 mm Hg vs +1.6 mm Hg, P < .001) and reduction in vasopressor dosage (-0.20 μg/kg/min vs +0.04 μg/kg/min; P < .001) compared with nonresponders at 3 h. Variables associated with favorable hemodynamic response included lower lactate concentration (OR 1.11; 95% CI, 1.05-1.17, P < .001) and receipt of vasopressin (OR, 6.05; 95% CI, 1.98-18.6; P = .002). In severity-adjusted multivariate analysis, hemodynamic responsiveness to angiotensin II was associated with reduced likelihood of 30-day mortality (hazard ratio, 0.50; 95% CI, 0.35-0.71; P < .001). Arrhythmias occurred in 28 patients (10%) and VTE was identified in 4 patients.

INTERPRETATION

In postmarketing use for vasopressor-refractory shock, 67% of angiotensin II recipients demonstrated a favorable hemodynamic response. Patients with lower lactate concentrations and those receiving vasopressin were more likely to respond to angiotensin II. Patients who responded to angiotensin II experienced reduced mortality.

Characteristics and Outcomes of Kidney Transplant Recipients Requiring High-Acuity Care After Transplant Surgery: A 10-Year Single-Center Study

Objective

To study the characteristics and outcomes of a cohort of kidney transplant recipients who required high-acuity care after transplant surgery.

Patients and Methods

All adult (aged ≥18 years) solitary kidney transplant recipients from January 1, 2007, through December 31, 2016, were screened and those who required high-acuity care within the same hospitalization were enrolled. Patient demographic and clinical data were collected from the departmental database and electronic DataMart.

Results

Of 1525 patients, 266 (17.4%) required high-acuity care after the kidney transplant operation: 166 (62.4%) directly from the operating room and 100 (37.6%) after an interval during the same hospitalization. Overall, 2 main indications were hypotension (n=87; 32.7%) and cardiac rhythm disturbances (n=83; 31.2%). Recipients in the direct admission group had higher medium body mass index (31.0 [interquartile range, 26.6-36.0] vs 28.0 [interquartile range, 24.3-32.4] kg/m²; P<.001) and were more likely to have undergone a concomitant procedure with the transplant surgery. Overall, in-hospital mortality was 1.9% (n=5).

Conclusion

In contemporary practice, patients with higher body mass index are more likely to require high-acuity care immediately after kidney transplant surgery. The most common reasons are hypotension and cardiac rhythm disorders. The overall intensive care unit mortality rate of these patients is low. However, these patients are at risk for graft loss and death in the long term compared with patients who do not require intensive care unit care after transplant surgery.

Patterns of Cystatin C Uptake and Use Across and Within Hospitals

OBJECTIVE

To characterize the use of cystatin C (cysC) across and within hospitals.

PATIENTS AND METHODS

This 2-part study first evaluated access to cysC testing across 129 hospitals in the state of Minnesota, using a telephone-based survey. Second, granular data from a single center (Mayo Clinic) with on-site, rapid-turnaround testing (<1 day) and automated estimated glomerular filtration rate (eGFR) reporting was used to describe temporal patterns. The characteristics of hospitals that offered cysC testing and of patients who underwent rapid cysC testing at Mayo Clinic between January 1, 2011, and March 31, 2018, were described. Poisson regression analyzed temporal trends in cysC testing.

RESULTS

Of the 114 hospitals (88%) that responded to the statewide survey, cysC was available in 91 (80%), but only 3 of 91 (3%) reported a turnaround time of <1 day. At Mayo Clinic, cysC use increased from 0.74 tests per 1000 patient-days in 2011 to 14 tests per 1000 patient-days in 2018 (P=.004). Of the 3774 patients with cysC tests, the mean first available eGFR was 46 mL/min per 1.73 m2 using cysC and 59 mL/min per 1.73 m2 using serum creatinine (P<.001). CysC testing was used across all intensities of care and was ordered by a variety of specialties. Nephrology was consulted in only 42% of cases.

CONCLUSION

In the hospital, rapid-turnaround cysC testing is necessary for practical use but was not widely available in Minnesota. When available, a marked increase in cysC testing was observed over the study timeframe. Additional research is needed to determine optimal strategies for implementation of cysC within hospitals.

Elastic Bandage vs Hypertonic Albumin for Diuretic-Resistant Volume-Overloaded Patients in Intensive Care Unit: A Propensity-Match Study

OBJECTIVE

To compare elastic bandage (EB) vs hypertonic albumin solution administration to increase fluid removal by enhancing loop diuretic efficiency (DE) in patients with volume overload and diuretic resistance.

PATIENTS AND METHODS

In this historic cohort study with propensity matching, we included diuretic-resistant adult (≥18 years) patients with volume overload after fluid resuscitation admitted in the intensive care unit from January 1, 2006, through June 30, 2017. Regression models and propensity matching were used to assess the associations of these interventions with changes in DE and other clinical outcomes.

RESULTS

Of 1147 patients (median age, 66; interquartile range [IQR], 56-76 years; 51% [n=590] men), 384 (33%) received EB and 763 (67%) received hypertonic albumin solution. In adjusted models, EB was significantly associated with higher DE compared with hypertonic albumin solution (odds ratio, 1.37; 95% CI, 1.04 to 1.81; P=.004). After propensity matching of 345 pairs, DE remained significantly different between the 2 groups (median, 2111; IQR, 1092 to 4665 mL for EB vs median, 1829; IQR, 1032 to 3436 mL for hypertonic albumin solution; P=.02). EB, male sex, lower baseline serum urea nitrogen level, lower Charlson Comorbidity Index score, and higher baseline left ventricular ejection fraction were DE determinants. The lowest DE quartile (<1073 mL/40-mg furosemide equivalent) following adjustment for known predictors of mortality remained independently associated with higher 90-day death rate (odds ratio, 1.64; 95% CI, 1.13 to 2.36; P=.009).

CONCLUSION

EB use is associated with greater DE than hypertonic albumin solution during the deescalation phase of sepsis resuscitation. Prospective clinical trials would validate the findings of this hypothesis-generating study.

Hyperkalemia Is Associated With Increased Mortality Among Unselected Cardiac Intensive Care Unit Patients

Background

Hyperkalemia has been associated with increased mortality in patients with myocardial infarction, but few data exist regarding hyperkalemia in cardiac intensive care unit (CICU) patients. We hypothesize that hyperkalemia is associated with increased mortality in unselected CICU patients.

Methods and Results

We retrospectively reviewed a historical cohort of 9681 CICU patients admitted from January 2007 to December 2015. Hyperkalemia was defined as admission potassium ≥5.0 mEq/L and hypokalemia as admission potassium <3.5 mEq/L. Multivariate logistic regression was used to determine predictors of in‐hospital mortality. Postdischarge survival was assessed using Kaplan–Meier analysis and Cox proportional hazards models. The mean age of included patients was 67±15 years, with 36% females, and in‐hospital mortality was 9%. Hyperkalemia occurred in 1187 (12.3%) and hypokalemia occurred in 719 (7.4%) patients. Both patients with hyperkalemia (unadjusted odds ratio, 2.85; 95% CI, 2.40–3.39; P<0.001) and patients with hypokalemia (unadjusted odds ratio, 2.31; 95% CI, 1.85–2.88; P<0.001) were at increased risk of unadjusted in‐hospital mortality. After adjustment for illness severity and renal function, only patients with hyperkalemia demonstrated increased risk of in‐hospital death (adjusted odds ratio, 1.44; 95% CI, 1.11–1.87; P=0.006). Among hospital survivors, only patients with hyperkalemia had lower postdischarge survival by Kaplan–Meier analysis (P<0.001). After adjustment for illness severity and renal function, hospital survivors with admission hyperkalemia remained at increased risk for postdischarge mortality (adjusted hazard ratio, 1.20; 95% CI, 1.08–1.34; P<0.001).

Conclusions

Hyperkalemia on CICU admission is associated with higher in‐hospital and postdischarge mortality, independent of renal function and illness severity. These findings emphasize the importance of potassium abnormalities as a risk predictor in patients admitted to the CICU.

Incidence of Acute Kidney Injury Among Critically Ill Patients With Brief Empiric Use of Antipseudomonal β-Lactams With Vancomycin

BACKGROUND

Nephrotoxins contribute to 20%-40% of acute kidney injury (AKI) cases in the intensive care unit (ICU). The combination of piperacillin-tazobactam (PTZ) and vancomycin (VAN) has been identified as nephrotoxic, but existing studies focus on extended durations of therapy rather than the brief empiric courses often used in the ICU. The current study was performed to compare the risk of AKI with a short course of PTZ/VAN to with the risk associated with other antipseudomonal β-lactam/VAN combinations.

METHODS

The study included a retrospective cohort of 3299 ICU patients who received ≥24 but ≤72 hours of an antipseudomonal β-lactam/VAN combination: PTZ/VAN, cefepime (CEF)/VAN, or meropenem (MER)/VAN. The risk of developing stage 2 or 3 AKI was compared between antibiotic groups with multivariable logistic regression adjusted for relevant confounders. We also compared the risk of persistent kidney dysfunction, dialysis dependence, or death at 60 days between groups.

RESULTS

The overall incidence of stage 2 or 3 AKI was 9%. Brief exposure to PTZ/VAN did not confer a greater risk of stage 2 or 3 AKI after adjustment for relevant confounders (adjusted odds ratio [95% confidence interval] for PTZ/VAN vs CEF/VAN, 1.11 [.85-1.45]; PTZ/VAN vs MER/VAN, 1.04 [.71-1.42]). No significant differences were noted between groups at 60-day follow-up in the outcomes of persistent kidney dysfunction (P = .08), new dialysis dependence (P = .15), or death (P = .09).

CONCLUSION

Short courses of PTZ/VAN were not associated with a greater risk of short- or 60-day adverse renal outcomes than other empiric broad-spectrum combinations.

Neuropathology of COVID-19: a spectrum of vascular and acute disseminated encephalomyelitis (ADEM)-like pathology

We report the neuropathological findings of a patient who died from complications of COVID-19. The decedent was initially hospitalized for surgical management of underlying coronary artery disease. He developed post-operative complications and was evaluated with chest imaging studies. The chest computed tomography (CT) imaging results were indicative of COVID-19 and he was subsequently tested for SARS-CoV-2, which was positive. His condition worsened and he died after more than 2 weeks of hospitalization and aggressive treatment. The autopsy revealed a range of neuropathological lesions, with features resembling both vascular and demyelinating etiologies. Hemorrhagic white matter lesions were present throughout the cerebral hemispheres with surrounding axonal injury and macrophages. The subcortical white matter had scattered clusters of macrophages, a range of associated axonal injury, and a perivascular acute disseminated encephalomyelitis (ADEM)-like appearance. Additional white matter lesions included focal microscopic areas of necrosis with central loss of white matter and marked axonal injury. Rare neocortical organizing microscopic infarcts were also identified. Imaging and clinical reports have demonstrated central nervous system complications in patients' with COVID-19, but there is a gap in our understanding of the neuropathology. The lesions described in this case provide insight into the potential parainfectious processes affecting COVID-19 patients, which may direct clinical management and ongoing research into the disease. The clinical course of the patient also illustrates that during prolonged hospitalizations neurological complications of COVID may develop, which are particularly difficult to evaluate and appreciate in the critically ill.

Hospital-Acquired Serum Chloride Derangements and Associated In-Hospital Mortality

Background: We aimed to describe the incidence of hospital-acquired dyschloremia and its association with in-hospital mortality in general hospitalized patients. Methods: All hospitalized patients from 2009 to 2013 who had normal admission serum chloride and at least two serum chloride measurements in the hospital were studied. The normal range of serum chloride was defined as 100–108 mmol/L. Hospital serum chloride levels were grouped based on the occurrence of hospital-acquired hypochloremia and hyperchloremia. The association of hospital-acquired hypochloremia and hyperchloremia with in-hospital mortality was analyzed using logistic regression. Results: Among the total of 39,298 hospitalized patients, 59% had persistently normal hospital serum chloride levels, 21% had hospital-acquired hypochloremia only, 15% had hospital-acquired hyperchloremia only, and 5% had both hypochloremia and hyperchloremia. Compared with patients with persistently normal hospital serum chloride levels, hospital-acquired hyperchloremia only (odds ratio or OR 2.84; p < 0.001) and both hospital-acquired hypochloremia and hyperchloremia (OR 1.72; p = 0.004) were associated with increased in-hospital mortality, whereas hospital-acquired hypochloremia only was not (OR 0.91; p = 0.54). Conclusions: Approximately 40% of hospitalized patients developed serum chloride derangements. Hospital-acquired hyperchloremia, but not hypochloremia, was associated with increased in-hospital mortality.

Inpatient Kidney Function Recovery among Septic Shock Patients Who Initiated Kidney Replacement Therapy in the Hospital

BACKGROUND

Sepsis and septic shock are life-threatening causes of acute kidney injury (AKI) frequently seen and managed in intensive care units (ICUs). Sepsis-associated AKI (SA-AKI) independently contributes to the mortality of sepsis. Understanding the potential factors involved in kidney function recovery may further aid in the prevention and management of SA-AKI. This study aimed to describe the clinical characteristics of septic shock patients who required kidney replacement therapy and factors associated with kidney function recovery.

METHODS

We conducted a retrospective cohort study of adult septic shock patients who received in-hospital kidney replacement therapy at medical intensive care unit (MICU) at the Mayo Clinic, Rochester, from January 1, 2006, to May 31, 2018. Kidney function recovery was defined as liberation from kidney replacement therapy before hospital discharge. Associations between clinical features and kidney recovery were analyzed using multivariable Fine and Gray regression accounting for death as a competing event.

RESULTS

Our retrospective cohort consisted of 229 patients with a median (interquartile range [IQR]) age of 64 (52-74) years: 55% were men, 89% were Caucasians, 39% had diabetes mellitus (DM), 16% had heart failure, APACHE (Acute Physiology and Chronic Health Evaluation) III score was 105 (84-123), and SOFA (Sequential [Sepsis-related] Organ Failure Assessment) score was 12 (9-14). The patients received 1,567 (524-4,108) mL of intravenous fluids in the first 3 h, 92% required vasopressor support, and 83% required mechanical ventilation. The median MICU and hospital stays were 7 (4-13) and 19 (10-31) days, respectively. Median (IQR) kidney replacement therapy duration was 7 (3.5-17.1) days. Among 158 ICU survivors, 73 (46%) patients were weaned from RRT in ICU and 85 (54%) were transitioned to intermittent RRT. A higher volume of fluid resuscitation in the first 3 h (hazard ratio [HR] = 1.07 per 1 L, CI: 1.01-1.14, p = 0.04) and a history of DM (HR = 1.70, CI: 1.14-2.54, p = 0.009) were associated with kidney function recovery.

CONCLUSION

Among septic shock patients who initiated kidney replacement therapy in the MICU, 41% recovered kidney function before discharge. A higher initial fluid resuscitation volume was associated with recovery, and interestingly, patients with DM had a higher chance of recovery.