Association of Kidney Cysts With Progressive CKD After Radical Nephrectomy.

RATIONALE & OBJECTIVE: Simple kidney cysts, which are common and usually considered of limited clinical relevance, are associated with older age and lower glomerular filtration rate (GFR), but little has been known of their association with progressive chronic kidney disease (CKD). STUDY DESIGN: Observational cohort study. SETTING & PARTICIPANTS: Patients with presurgical computed tomography or magnetic resonance imaging who underwent a radical nephrectomy for a tumor; we reviewed the retained kidney images to characterize parenchymal cysts at least 5mm in diameter according to size and location. EXPOSURE: Parenchymal cysts at least 5mm in diameter in the retained kidney. Cyst characteristics were correlated with microstructural findings on kidney histology. OUTCOME: Progressive CKD defined by dialysis, kidney transplantation, a sustained≥40% decline in eGFR for at least 3 months, or an eGFR<10mL/min/1.73m2 that was at least 5mL/min/1.73m2 below the postnephrectomy baseline for at least 3 months. ANALYTICAL APPROACH: Cox models assessed the risk of progressive CKD. Models adjusted for baseline age, sex, body mass index, hypertension, diabetes, eGFR, proteinuria, and tumor volume. Nonparametric Spearman's correlations were used to examine the association of the number and size of the cysts with clinical characteristics, kidney function, and kidney volumes. RESULTS: There were 1,195 patients with 50 progressive CKD events over a median 4.4 years of follow-up evaluation. On baseline imaging, 38% had at least 1 cyst, 34% had at least 1 cortical cyst, and 8.7% had at least 1 medullary cyst. A higher number of cysts was associated with progressive CKD and was modestly correlated with larger nephrons and more nephrosclerosis on kidney histology. The number of medullary cysts was more strongly associated with progressive CKD than the number of cortical cysts. LIMITATIONS: Patients who undergo a radical nephrectomy may differ from the general population. A radical nephrectomy may accelerate the risk of progressive CKD. Genetic testing was not performed. CONCLUSIONS: Cysts in the kidney, particularly the medulla, should be further examined as a potentially useful imaging biomarker of progressive CKD beyond the current clinical evaluation of kidney function and common CKD risk factors. PLAIN-LANGUAGE SUMMARY: Kidney cysts are common and often are considered of limited clinical relevance despite being associated with lower glomerular filtration rate. We studied a large cohort of patients who had a kidney removed due to a tumor to determine whether cysts in the retained kidney were associated with kidney health in the future. We found that more cysts in the kidney and, in particular, cysts in the deepest tissue of the kidney (the medulla) were associated with progressive kidney disease, including kidney failure where dialysis or a kidney transplantation is needed. Patients with cysts in the kidney medulla may benefit from closer monitoring.

Prognostic Implications of a Morphometric Evaluation for Chronic Changes on All Diagnostic Native Kidney Biopsies.

BACKGROUND: Semiquantitative visual inspection for glomerulosclerosis, interstitial fibrosis, and arteriosclerosis is often used to assess chronic changes in native kidney biopsies. Morphometric evaluation of these and other chronic changes may improve the prognostic assessment. METHODS: We studied a historical cohort of patients who underwent a native kidney biopsy between 1993 and 2015 and were followed through 2021 for ESKD and for progressive CKD (defined as experiencing 50% eGFR decline, temporary dialysis, or ESKD). Pathologist scores for the percentages of globally sclerosed glomeruli (GSG), interstitial fibrosis and tubular atrophy (IFTA), and arteriosclerosis (luminal stenosis) were available. We scanned biopsy sections into high-resolution images to trace microstructures. Morphometry measures were percentage of GSG; percentage of glomerulosclerosis (percentage of GSG, ischemic-appearing glomeruli, or segmentally sclerosed glomeruli); percentage of IFTA; IFTA foci density; percentage of artery luminal stenosis; arteriolar hyalinosis counts; and measures of nephron size. Models assessed risk of ESKD or progressive CKD with biopsy measures adjusted for age, hypertension, diabetes, body mass index, eGFR, and proteinuria. RESULTS: Of 353 patients (followed for a median 7.5 years), 75 developed ESKD and 139 experienced progressive CKD events. Visually estimated scores by pathologists versus morphometry measures for percentages of GSG, IFTA, and luminal stenosis did not substantively differ in predicting outcomes. However, adding percentage of glomerulosclerosis, IFTA foci density, and arteriolar hyalinosis improved outcome prediction. A 10-point score using percentage of glomerulosclerosis, percentage of IFTA, IFTA foci density, and any arteriolar hyalinosis outperformed a 10-point score based on percentages of GSG, IFTA, and luminal stenosis >50% in discriminating risk of ESKD or progressive CKD. CONCLUSION: Morphometric characterization of glomerulosclerosis, IFTA, and arteriolar hyalinosis on kidney biopsy improves prediction of long-term kidney outcomes.

Outcomes After Noncardiac Surgery for Patients with Pulmonary Hypertension: A Historical Cohort Study.

OBJECTIVE: Pulmonary hypertension (PH) is a substantial preoperative risk factor. For this study, morbidity and mortality were examined after noncardiac surgery in patients with precapillary PH. DESIGN: A retrospective cohort study. SETTING: Quaternary medical center in Rochester, MN. PARTICIPANTS: Adults with PH undergoing noncardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The PH and surgical databases were reviewed from 2010 to 2017. Patients were excluded if PH was attributable to left-sided heart disease or they had undergone cardiac or transplantation surgeries. To assess whether PH-specific diagnostic or cardiopulmonary testing parameters were predictive of perioperative complications, generalized estimating equations were used. Of 196 patients with PH, 53 (27%) experienced 1 or more complications, including 5 deaths (3%) within 30 days. After adjustment for age and PH type, there were more complications in those undergoing moderate- to high-risk versus low-risk procedures (odds ratio [OR] 4.17 [95% confidence interval {CI} 2.07-8.40]; p < 0.001). After adjustment for age, surgical risk, and PH type, the complication risk was greater for patients with worse functional status (OR 2.39 [95% CI 1.19-4.78]; p = 0.01 for classes III/IV v classes I/II) and elevated serum N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) (OR 2.28 [95% CI 1.05-4.96]; p = 0.04 for ≥300 v <300 pg/mL). After adjusting for age, surgical risk, and functional status, elevated NT-proBNP remained associated with increased risk (OR 2.23 [95% CI 1.05-4.76]; p = 0.04). CONCLUSION: PH patients undergoing noncardiac surgery have a high frequency of complications. Worse functional status, elevated serum NT-proBNP, and higher-risk surgery are predictive of worse outcome.

Features of Adult Hyperammonemia Not Due to Liver Failure in the ICU.

OBJECTIVES: To evaluate the epidemiology of hyperammonemia unrelated to liver failure in the critical care setting. DESIGN: Retrospective case series. SETTING: Critically ill patients admitted to ICUs at Mayo Clinic, Rochester, MN (medical ICU, two mixed medical-surgical ICUs, coronary care unit, or the cardiosurgical ICU) between July 1, 2004, and October 31, 2015. PATIENTS: Adult critically ill patients with hyperammonemia not related to acute or chronic liver failure. We excluded patients with diagnosis of moderate or severe liver disease, hyperbilirubinemia, and patients who denied the use of their medical records. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 3,908 ICU patients with hyperammonemia, 167 (4.5%) had no evidence of acute or chronic liver failure. One-hundred one patients (60.5%) were male with median age of 65.7 years (interquartile range, 50-74.5 yr) and median serum ammonia level of 68 µg/dL (interquartile range, 58-87 µg/dL). Acute encephalopathy was present in 119 patients (71%). Predisposing conditions included malnutrition 27 (16%), gastric bypass six (3.6%), total parenteral nutrition four (2.4%); exposure to valproic acid 17 (10%); status epilepticus 11 (6.6%), high tumour burden 19 (11.3%), and renal failure 82 (49.1%). Urea cycle defects were diagnosed in seven patients (4.1%). Hospital mortality was high (30%), and median ammonia level was higher among the nonsurvivors (74 vs 67 µg/dL; p = 0.05). Deaths were more likely in hyperammonemic patients who were older (p = 0.016), had greater illness severity (higher Acute Physiology and Chronic Health Evaluation III score, p < 0.01), malignancy (p < 0.01), and solid organ transplantation (p = 0.04), whereas seizure disorder was more common in survivors (p = 0.02). After adjustment, serum ammonia level was not associated with increased mortality. CONCLUSIONS: Hyperammonemia occurs in a substantial minority of critically ill patients without liver failure. These patients have a poor prognosis, although ammonia level per se is not independently associated with mortality. Serum ammonia should be measured when risk factors are present, such as nutritional deficiencies and protein refeeding, treatment with valproic acid, high tumour burden, and known or suspected urea cycle abnormalities.

Improving Diagnostic Fidelity: An Approach to Standardizing the Process in Patients With Emerging Critical Illness.

OBJECTIVE: To reliably improve diagnostic fidelity and identify delays using a standardized approach applied to the electronic medical records of patients with emerging critical illness. PATIENTS AND METHODS: This retrospective observational study at Mayo Clinic, Rochester, Minnesota, conducted June 1, 2016, to June 30, 2017, used a standard operating procedure applied to electronic medical records to identify variations in diagnostic fidelity and/or delay in adult patients with a rapid response team evaluation, at risk for critical illness. Multivariate logistic regression analysis identified predictors and compared outcomes for those with and without varying diagnostic fidelity and/or delay. RESULTS: The sample included 130 patients. Median age was 65 years (interquartile range, 56-76 years), and 47.0% (52 of 130) were women. Clinically significant diagnostic error or delay was agreed in 23 (17.7%) patients (κ=0.57; 95% CI, 0.40-0.74). Median age was 65.4 years (interquartile range, 60.3-74.8) and 9 of the 23 (30.1%) were female. Of those with diagnostic error or delay, 60.9% (14 of 23) died in the hospital compared with 19.6% (21 of 107) without; P<.001. Diagnostic error or delay was associated with higher Charlson comorbidity index score, cardiac arrest triage score, and do not intubate/do not resuscitate status. Adjusting for age, do not intubate/do not resuscitate status, and Charlson comorbidity index score, diagnostic error or delay was associated with increased mortality; odds ratio, 5.7; 95% CI, 2.0-17.8. CONCLUSION: Diagnostic errors or delays can be reliably identified and are associated with higher comorbidity burden and increased mortality.

Effect of Cognitive Status on the Receipt of Procedures Requiring Anesthesia and Critical Care Admissions in Older Adults.

OBJECTIVE: To investigate whether older adults with mild cognitive impairment (MCI) or dementia have higher rates of procedures requiring general anesthesia or intensive care unit (ICU) admissions compared with cognitively normal (CN) patients. PATIENTS AND METHODS: A population-based cohort, 70 to 89 years old at enrollment, underwent clinical and longitudinal neurocognitive testing to identify those with MCI and dementia. We analyzed the effects of cognitive status (CN, MCI, or dementia) at entry into the study from October 1, 2004, through December 31, 2014, on the risk of receiving procedures requiring surgical anesthesia and ICU admission. RESULTS: Of 2436 participants, 1977 (81%) were CN, 387 (16%) had MCI, and 72 (3%) had dementia. Cognitively impaired individuals were sicker. Compared with CN individuals, the likelihood of receiving a procedure requiring anesthesia was similar in participants with MCI (adjusted hazard ratio [aHR]=0.98; P=.78). Participants with dementia were less likely to receive these procedures (aHR=0.50; P=.02). Compared with CN participants, the likelihood of ICU admission for any indication was increased for those with MCI (aHR=1.24; P=.03) and dementia (aHR=1.59; P=.04). Admissions to the ICU after procedures were not different in patients with either MCI or dementia (aHR=0.96; P=.83 and aHR=1.01; P=.98, respectively). CONCLUSION: Patients with MCI or dementia are not more likely to undergo surgery, and neither are they more likely to require ICU admission after procedures. An increased rate of nonsurgical ICU admissions requires vigilance to prevent deterioration of nonsurgical diseases that may lead to ICU admissions.