The Association of Low Admission Serum Creatinine with the Risk of Respiratory Failure Requiring Mechanical Ventilation: A Retrospective Cohort Study

Low serum creatinine levels are associated with major post-operative complications in patients undergoing surgery with gynecologic oncologists

OBJECTIVE

Serum creatinine is a byproduct of muscle metabolism, and low creatinine is postulated to be associated with diminished muscle mass. This study examined the association between low pre-operative serum creatinine and post-operative outcomes.

METHODS

This retrospective cohort study utilized the 2014-2021 National Surgical Quality Improvement Program to identify patients undergoing surgery with gynecologic oncologists. Patients with missing pre-operative creatinine, end-stage renal disease, sepsis, septic shock, dialysis, or pregnancy were excluded. Pre-operative creatinine was categorized into markedly low (≤0.44 mg/dL), mildly low (0.45-0.64 mg/dL), normal (0.65-0.84 mg/dL), and four categories of elevated levels (0.85-1.04, 1.05-1.24, 1.25-1.44, and ≥1.45 mg/dL). Outcomes included major (≥Grade 3) 30-day complications, categorized into any complications, wound, cardiovascular and pulmonary, renal, infectious, and thromboembolic complications. Also examined were 30-day readmissions, reoperations, and mortality. Logistic regressions assessed the association between creatinine and complications, with stratification by albumin and sensitivity analysis with propensity score matching.

RESULTS

Among 84 786 patients, 0.8% had markedly low, 19.6% mildly low, and 50.2% normal creatinine; the remainder had elevated creatinine. As creatinine decreased, the risks of major complications increased in a dose-dependent manner on univariable and multivariable analyses. A total of 9.6% (n=63) markedly low patients experienced major complications, second to creatinine ≥1.45 mg/dL (9.9%, n=141). On multivariable models, both markedly and mildly low creatinine were associated with higher odds of major complications (OR 1.715, 95% CI 1.299 to 2.264 and OR 1.093, 95% CI 1.001 to 1.193) and infections (OR 1.575, 95% CI 1.118 to 2.218 and OR 1.165, 95% CI 1.048 to 1.296) versus normal. Markedly low creatinine had similar ORs to creatinine ≥1.45 mg/dL and was further associated with higher odds of cardiovascular and pulmonary complications (OR 2.301, 95% CI 1.300 to 4.071), readmissions (OR 1.403, 95% CI 1.045 to 1.884), and mortality (OR 2.718, 95% CI 1.050 to 7.031). After albumin stratification, associations persisted for markedly low creatinine. Propensity-weighted analyses demonstrated congruent findings.

CONCLUSIONS

Low creatinine levels are associated with major post-operative complications in gynecologic oncology in a dose-dependent manner. Low creatinine can offer useful information for pre-operative risk stratification, surgical counseling, and peri-operative management.

VAP risk index: Early prediction and hospital phenotyping of ventilator-associated pneumonia using machine learning

BACKGROUND

Ventilator-associated pneumonia (VAP) is a leading cause of morbidity and mortality in intensive care units (ICUs). Early identification of patients at risk of VAP enables early intervention, which in turn improves patient outcomes. We developed a predictive model for individualized risk assessment utilizing machine learning to identify patients at risk of developing VAP.

METHODS

The Philips eRI dataset, a multi-institution electronic medical record (EMR), was used for model development. For adult (≥18y) patients, we propose a set of criteria using indications of the start of a new antibiotic treatment temporally contiguous to a microbiological test to mark suspected infection events, of which those with a positive culture are labeled as presumed VAP if 1) the event occurs at least 48 h after intubation, and 2) there are no indications of community-acquired pneumonia (CAP) or other hospital-acquired infections (HAI) in the patient charts. The resulting VAP and no-VAP (control) cases were then used to build an ensemble of decision trees to predict the risk of VAP in the next 24 h using data on patients' demographics, vitals, labs, and ventilator settings.

RESULTS

The resulting model predicts the development of VAP 24 h in advance with an AUC of 76 % and AUPRC of 75 %. Additionally, we group hospitals that are similar in healthcare processes into distinct clusters and characterize VAP prediction for the identified hospital clusters. We show inter-hospital (teaching status and healthcare processes) and cohort-specific (age groups, gender, early vs late VAP, ICU mortality status) differences in VAP prediction and associated symptomologies.

CONCLUSIONS

Our proposed VAP criteria use clinical actions to mark incidences of presumed VAP infection, which enables the development of models for early detection of these events. We curated a patient cohort using these criteria and used it to build a model for predicting impending VAP events prior to clinical suspicions. We present a clustering approach for tailoring the VAP prediction model for different hospital types based on their EMR data characteristics. The model provides an instantaneous risk score that allows early interventions and confirmatory diagnostic actions.

The age-related association between serum creatinine and cardiorespiratory morbidity and mortality and fractures among adults with cerebral palsy

PURPOSE

Serum creatinine may be an objective biomarker of salient health issues in adults with cerebral palsy (CP). The objective was to assess the age-related association between serum creatinine with 3-year risk of cardiorespiratory morbidity/mortality and fracture among adults with CP.

PATIENTS AND METHODS

This retrospective cohort study used medical records between Jan. 1, 2012 and Oct. 2, 2022 from adults ≥18 years old with CP. The association between baseline serum creatinine with the 3-year risk of all-cause mortality, respiratory/cardiovascular morbidity/mortality, and fracture was assessed by age and sex using logistic regression. The discriminative ability of serum creatinine alone and in conjunction with other variables was assessed.

RESULTS

Over the 3-year follow-up, 8.3% of 1368 adults with CP had all-cause mortality, 25.6% had respiratory morbidity/mortality, 12.4% had cardiovascular morbidity/mortality, and 8.9% sustained a fracture. The association between serum creatinine with outcomes was dependent on age. For younger adults, lower creatinine had a higher odds ratio (OR) for all-cause mortality, respiratory morbidity/mortality, and fracture. For 51-60 year olds, higher creatinine had a higher OR for cardiovascular morbidity/mortality. Serum creatinine alone had modest prediction of outcomes, and generally improved prediction when added to models that included sex and co-occurring intellectual disabilities and epilepsy (c-statistic range, 0.54-0.84).

CONCLUSIONS

Lower serum creatinine may reflect frailty while higher levels may reflect kidney dysfunction, helping to explain the differential associations by age. Serum creatinine may be a useful biomarker as part of risk prediction models for these salient health issues for adults with CP.

Novel nutritional strategies to prevent muscle wasting

PURPOSE OF REVIEW

Muscle wasting in critical illness has proven to be refractory to physical rehabilitation, and to conventional nutritional strategies. This presents one of the central challenges to critical care medicine in the 21st century. Novel strategies are needed that facilitate nutritional interventions, identify patients that will benefit and have measurable, relevant benefits.

RECENT FINDINGS

Drug repurposing was demonstrated to be a powerful technique in the coronavirus disease 2019 pandemic, and may have similar applications to address the metabolic derangements of critical illness. Newer biological signatures may aid the application of these techniques and the association between changes in urea:creatinine ratio and the development of skeletal muscle wasting is increasing. A core outcome set for nutrition interventions in critical illness, supported by multiple international societies, was published earlier this year should be adopted by future nutrition trials aiming to attenuate muscle wasting.

SUMMARY

The evidence base for the lack of efficacy for conventional nutritional strategies in preventing muscle wasting in critically ill patients continues to grow. Novel strategies such as metabolic modulators, patient level biological signatures of nutritional response and standardized outcome for measurements of efficacy will be central to future research and clinical care of the critically ill patient.

Low Preoperative Serum Creatinine is Common and Associated With Poor Outcomes After Nonemergent Inpatient Surgery

OBJECTIVE

To assess the association between low preoperative serum creatinine and postoperative outcomes.

BACKGROUND

The association between low creatinine and poor surgical outcomes is not well understood.

METHODS

We identified patients with creatinine in the 7 days preceding nonemergent inpatient surgery in the American College of Surgeons National Surgical Quality Improvement Program database from 2005 to 2020. Multivariable logistic regression was used to examine the association between creatinine and 30-day mortality and major complications.

RESULTS

Of 1,809,576 patients, 27.8% of males and 23.5% of females had low preoperative serum creatinine, 14.6% experienced complications, and 1.2% died. For males, compared with the reference creatinine of 0.85 to 1.04, those with serum creatinine ≤0.44 had 55% increased odds of mortality [ adjusted odds ratio (aOR), 1.55; 95% CI, 1.29-1.86] and 82% increased odds of major complications (aOR, 1.82; 95% CI, 1.69-1.97). Similarly, for females, compared with the reference range of 0.65 to 0.84, those with serum creatinine ≤0.44 had 49% increased odds of mortality (aOR, 1.49; 95% CI, 1.32-1.67) and 76% increased odds of major complications (aOR, 1.76; 95% CI, 1.70-1.83). These associations persisted for the total cohort, among those with mildly low albumin, and for those with creatinine values measured 8 to 30 days preoperatively.

CONCLUSIONS

A low preoperative creatinine is common and associated with poor outcomes after nonemergent inpatient surgery. A low creatinine may help identify high-risk patients who may benefit from further evaluation and optimization.

Association between predialysis creatinine and mortality in acute kidney injury patients requiring dialysis

Background

Creatinine is widely used to estimate renal function, but this is not practical in critical illness. Low creatinine has been associated with mortality in many clinical settings. However, the associations between predialysis creatinine level, Sepsis-related Organ Failure Assessment (SOFA) score, fluid overload, and mortality in acute kidney injury patients receiving dialysis therapy (AKI-D) has not been fully addressed.

Methods

We extracted data for AKI-D patients in the eICU and MIMIC databases. We conducted a retrospective observational cohort study using the eICU dataset. The study cohort was divided into the high-creatine group and the low-creatinine group by the median value (4 mg/dL). The baseline patient information included demographic data, laboratory tests, medications, and comorbid conditions. The independent association of creatinine level with 30-day mortality was examined using multivariate logistic regression analysis. In sensitivity analyses, the associations between creatinine, SOFA score, and mortality were analyzed in patients with or without fluid overload. We also carried out an external validity using the MIMIC dataset.

Results

In all 1,600 eICU participants, the 30-day mortality rate was 34.2%. The crude overall mortality rate in the low-creatinine group (44.9%) was significantly higher than that in the high-creatinine group (21.9%; P < 0.001). In the fully adjusted models, the low-creatinine group was associated with a higher risk of 30-day mortality (odds ratio, 1.77; 95% confidence interval, 1.29–2.42; P < 0.001) compared with the high-creatinine group. The low-creatinine group had higher SOFA and nonrenal SOFA scores. In sensitivity analyses, the low-creatinine group had a higher 30-day mortality rate with regard to the BMI or albumin level. Fluid overloaded patients were associated with a significantly worse survival in the low-creatinine group. The results were consistent when assessing the external validity using the MIMIC dataset.

Conclusions

In patients with AKI-D, lower predialysis creatinine was associated with increased mortality risk. Moreover, the mortality rate was substantially higher in patients with lower predialysis creatinine with concomitant elevation of fluid overload status.

Influence of Fasting Plasma Glucose Level on Admission of COVID-19 Patients: A Retrospective Study

BACKGROUND

The coronavirus disease 2019 (COVID-19) is a serious global health threat and has spread dramatically worldwide. Prolonged viral shedding is associated with a more severe disease course and inflammatory reaction. Blood glucose levels were significantly associated with an increased hazard ratio (HR) for poor outcomes in COVID-19 patients.

OBJECTIVE

Previous studies focused primarily on the relationship between blood glucose and mortality or severe outcomes, but there were few research studies on the relationship between fasting plasma glucose (FPG) and duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA positive status. To explore the relationship between FPG levels and prolonged duration of SARS-CoV-2 viral positivity, the clinical data of COVID-19 patients were analyzed.

METHOD

In this retrospective study, 99 cases of COVID-19 patients in Beijing Ditan Hospital were recruited, and their clinical and laboratory findings at admission were collected and analyzed. Furthermore, the risk factors for prolonged duration of SARS-CoV-2 RNA shedding were identified, and the relationship between FPG levels and the prolonged presence of SARS-CoV-2 RNA was evaluated.

RESULT

We found that elevated FPG levels were correlated with longer duration of SARS-CoV-2 RNA positivity, classification of COVID-19, imaging changes of chest CT, inflammation-related biomarkers, and CD8+ T cell number in COVID-19 patients. In a logistic regression model, after adjusting for gender and age, COVID-19 patients with elevated FPG were more likely to had longer duration of SARS-CoV-2 RNA positivity than those with normal FPG levels (OR 3.053 [95% CI 1.343, 6.936]).

CONCLUSION

Higher FPG levels (≥6.1 mmol/l) at admission was an independent predictor for prolonged SARS-CoV-2 shedding, regardless of a known history of diabetes. It suggests that intensive monitoring and control of blood glucose are important for all COVID-19 patients.

BIOCHEMICAL PARAMETERS OF KIDNEY FUNCTION IN DONORS UNDER THE PRESENCE OF ANTI-SARS-CoV-2 IgG IN BLOOD

Pandemic caused by SARS-CoV-2 virus in the world influences negatively on economic and social life, health care system. Conctracted COVID-19 patients suffered from outcome this disease after recovery because of SARS-CoV-2 has affected system disorder of body. Problems of digestion, blood coagulation, humoral and nervous systems could be discovered background disorder of respiratory system working. Besides, the clinical researches agree the changes of functioning kidneys in hospitalized patients suffered by SARS-CoV-2 virus. Therefore the pathological status of kidneys could develop in post-COVID-19 period. Our research is aimed to analysis of changes of concentration albumin, creatinine, urea and urea acid in blood plasma of donors with different titers of anti-SARS-CoV-2 IgG. Groups of donors were selected, in which the maximum and minimum values of the studied parameters were observed relative to the control group - donors without anti-SARS-CoV-2 IgG in blood. We determined that donor group with minimum titer of anti-SARS-CoV-2 IgG – 10 ± 3 Index (S/C) – have been characterized the maximum concentration of creatinine, urea and urea acid. Moreover the donor group with titer of anti-SARS-CoV-2 IgG 75 ± 5 Index (S/C) had the minimum concentration of albumin, creatinine, urea and urea acid. Obtained results could be linked with the potential influence of SARS-CoV-2 virus to kindey cells and consequents of immune response to infection caused by COVID-19 disease. Our research could be useful for treatment of COVID-19, which would involve the clinical therapy aimed not only at neutralizing the virus in the body, but also at reducing the negative load on the kidneys to prevent the development of pathological conditions in the post-COVID-19 period.

Novel methods to identify and measure catabolism

PURPOSE OF REVIEW

Assess current potential catabolism-biomarkers to characterize patients developing prolonged critical illness.

RECENT FINDINGS

A raised urea-to-creatinine ratio (UCR) during critical illness is negatively associated with muscle mass with greater increases in UCR seen patients developing persistent critical illness. Similarly, sarcopenia index (a ratio of creatinine to cystatin-c concentrations) correlates well to muscle mass in intensive care populations. Elevated growth/differentiation factor-15 (GDF-15) has been inconsistently associated with muscle loss. Although GDF-15 was a poor marker of feeding tolerance, it has been associated with worse prognosis in intensive care.

SUMMARY

UCR is an available and clinically applicable biomarker of catabolism. Similarly, sarcopenia index can be used to assess muscle mass and indirectly measure catabolism based on readily available biochemical measurements. The utility of novel biomarkers, such as GDF-15 is less established.

Serum ionised calcium and the risk of acute respiratory failure in hospitalised patients: a single-centre cohort study in the USA

OBJECTIVES

The objective of this study was to evaluate the risk of acute respiratory failure in all hospitalised patients based on admission serum ionised calcium.

DESIGN

A retrospective cohort study.

SETTING

A tertiary referral hospital in Rochester, Minnesota, USA.

PARTICIPANTS

All hospitalised patients who had serum ionised calcium measurement within 24 hours of hospital admission from January 2009 to December 2013. Patients who were mechanically ventilated at admission were excluded.

PREDICTORS

Admission serum ionised calcium levels was stratified into six groups: ≤4.39, 4.40-4.59, 4.60-4.79, 4.80-4.99, 5.00-5.19 and ≥5.20 mg/dL.

PRIMARY OUTCOME MEASURE

The primary outcome was the development of acute respiratory failure requiring mechanical ventilation during hospitalisation. Logistic regression analysis was fit to assess the independent risk of acute respiratory failure based on various admission serum ionised calcium, using serum ionised calcium of 5.00-5.19 mg/dL as the reference group.

RESULTS

Of 25 709 eligible patients, with the mean serum ionised calcium of 4.8±0.4 mg/dL, acute respiratory failure requiring mechanical ventilation occurred in 2563 patients (10%). The incidence of acute respiratory failure was lowest when admission serum ionised calcium was 5.00-5.19 mg/dL, with the progressively increased risk of acute respiratory failure with decreased serum ionised calcium. In multivariate analysis with adjustment for potential confounders, the increased risk of acute respiratory failure requiring mechanical ventilation was significantly associated with admission serum ionised calcium of ≤4.39 (OR 2.52; 95% CI 2.12 to 3.00), 4.40-4.59 (OR 1.76; 95% CI 1.49 to 2.07) and 4.60-4.79 mg/dL (OR 1.48; 95% CI 1.27 to 1.72), compared with serum ionised calcium of 5.00-5.19 mg/dL. The risk of acute respiratory failure was not significantly increased when serum ionised calcium was at least 4.80 mg/dL.

CONCLUSION

The increased risk of acute respiratory failure requiring mechanical ventilation was observed when admission serum ionised calcium was lower than 4.80 mg/dL in hospitalised patients.

Risk of respiratory failure among hospitalized patients with various admission serum potassium levels

BACKGROUND

The objective of this study was to assess the relationship between admission serum potassium and the risk of respiratory failure requiring mechanical ventilation in all hospitalized patients.

METHODS

All non-dialysis and non-mechanically ventilated patients who had serum potassium measurement at admission from 2011 to 2013 were studied. Serum potassium levels were stratified into five groups; ≤3.4, 3.5 to 3.9, 4.0 to 4.4, 4.5 to 4.9, 5.0 to 5.4, and ≥5.5 mEq/L. The outcome of interest was the respiratory failure requiring mechanical ventilation during hospitalization. Logistic regression analysis was performed to assess the independent risk of in-hospital respiratory failure requiring mechanical ventilation based on various admission serum potassium, using serum potassium of 4.0 to 4.4 mEq/L as the reference group.

RESULTS

Of 67,034 eligible patients, with the mean admission serum potassium of 4.2 ± 0.5 mEq/L, 2,886 (4.3%) patients developed respiratory failure requiring mechanical ventilation during hospitalization. As demonstrated by U-shaped association, increased risk of in-hospital respiratory failure was significantly associated with low admission serum potassium ≤ 3.4 mEq/L (odds ratio 1.36, p-value <0.001) and high admission serum potassium ≥5.5 mEq/L (odds ratio 1.37, p-value = 0.01).

CONCLUSION

Increased risk of in-hospital respiratory failure requiring mechanical ventilation was noted when serum potassium was below 3.5 mEq/L or above 5.4 mEq/L at the time of hospital admission. Patients with either hypokalemia or hyperkalemia are at risk of respiratory failure requiring mechanical ventilation.

Risk of acute respiratory failure among hospitalized patients with various admission serum albumin levels: A cohort study

Serum albumin is a marker of nutritional and frailty status. This study aimed to assess the association between serum albumin at the time of admission and the risk of acute respiratory failure (ARF) in hospitalized patientsThis cohort study, performed at a tertiary referral hospital, included all hospitalized adult patients from January 2009 to December 2013 who had serum albumin measurement and were not on mechanical ventilation within 24 hours of hospital admission. Serum albumin was stratified into 2.4, 2.5 to 2.9, 3.0 to 3.4, 3.5 to 3.9, 4.0 to 4.4, and ≥4.5 g/dL. Multivariate logistic regression analysis was performed to obtain adjusted odds ratio (OR) of risk of ARF requiring mechanical ventilation based on various admission serum albumin levels.Of 12,719 patients, ARF requiring mechanical ventilation occurred in 1128 (8.9%) during hospitalization. Hypoalbuminemia was associated with increased risk of ARF, in particular when serum albumin was ≤2.4 g/dL. Compared with serum albumin of 4.0-4.4 g/dL, serum albumin ≤2.4 g/dL at admission was associated with 2.38-time higher odds of ARF during hospitalization (OR 2.38, 95% confidence interval [CI] 1.84-3.07). In contrast, elevated serum albumin ≥4.5 g/dL was associated with lower odds of ARF (OR 0.68, 95% CI 0.48-0.97).Admission serum albumin level lower than 3.5 g/dL was associated with a higher risk of ARF requiring mechanical ventilation, whereas elevated serum albumin level at least 4.5 g/dL was associated with a lower risk of ARF. Therefore, admission albumin level at admission might be useful in the prediction of ARF during hospitalization.