Comparison of Two Waves of COVID-19 in Critically Ill Patients: A Retrospective Observational Study.

Background: The SARS-CoV-2 virus caused the global COVID-19 pandemic, with waxing and waning course. This study was conducted to compare outcomes in the first two waves, in mechanically ventilated patients. Methods: This retrospective observational study included all mechanically ventilated COVID-19 patients above 18 years of age, between March 2020 and January 2021. Patients were grouped into first wave from March 2020 to July 2020, and second wave from August 2020 to January 2021. Outcome measures were mortality, the development of acute kidney injury (AKI), and need for renal replacement therapy (RRT). Univariate and multivariate cox regression analysis were used to delineate risk factors for the outcome measures. Results: A total of 426 patients, 285 in the first wave and 185 in the second wave, were included. The incidence of AKI was significantly lower in the second wave (72% vs. 63%; p=0.04). There was no significant difference in mortality (70% vs. 63%; p=0.16) and need for RRT (36% vs. 30%; p=0.1). Risk factors for mortality were increasing age and AKI in both waves, and chronic kidney disease (CKD) (adj. HR 1.7; 95% CI 1.02-2.68; p=0.04) in the second wave. Risk factors for AKI were CKD in both the waves, while it was diabetes (adj. HR 1.4; 95% CI 1.02-1.95; p=0.04) and increasing age in the first wave. Remdesivir (adj. HR 0.5; 95% CI 0.3-0.7; p < 0.01) decreased the risk of AKI, and convalescent plasma (adj. HR 0.5; 95% CI 0.3-0.9; p=0.02) decreased the risk of mortality in the first wave, however, such benefit was not observed in the second wave. Conclusions: Our study shows a decrease in the incidence of AKI in critically ill patients, however, the reason for this decrease is still unknown. Studies comparing the waves of the pandemic would not only help in understanding disease evolution but also to develop tailored management strategies.

Clotting of Hemodialysis Access in Patients with COVID-19 in an Inner-City Hospital.

BACKGROUND: An increased incidence of thrombotic complications in patients with coronavirus disease 2019 (COVID-19) has been reported. Severe acute kidney injury (AKI) is one of the major clinical manifestations of COVID-19 with the need for renal replacement therapy. It was observed that hemodialysis (HD) accesses tended to thrombose more often in the COVID-19 population than in non-COVID-19 patients. We hypothesize that the hypercoagulable state of COVID-19 is associated with higher incidence of access clotting. METHOD: In this retrospective single-centered study at Kings County Hospital in New York City, 1,075 patients with COVID-19 were screened, and 174 patients who received HD from January 3, 2021 to May 15, 2020 were enrolled to examine the risk factors of dialysis access clotting in patients with COVID-19. RESULTS: Of the 174 patients, 109 (63%) were COVID-19 positive. 39 (22.6%) patients had dialysis access clotting at least once during their hospitalization, and they had significantly higher body mass index (BMI) (p = 0.001), higher rates of COVID-19 (p = 0.015), AKI (p < 0.001), higher platelet counts (p = 0.029), higher lactate dehydrogenase levels (p = 0.009), and lower albumin levels (p = 0.001) than those without access malfunctions. Low albumin levels (p = 0.008), AKI (p = 0.008), and high BMI (p = 0.018) were risk factors associated with HD access clotting among COVID-19 patients. CONCLUSION: Patients with COVID-19 who receive HD for AKI with high BMI are at a higher risk of clotting their HD access.

Predicting ionized hypocalcemia: External validation of an ionized calcium prediction model in patients with COVID-19 and renal failure.

BACKGROUND: Ionized hypocalcemia is common in critically ill patients with COVID-19 and is associated with adverse outcomes. We previously developed a linear model that estimates ionized calcium (ICa) by adjusting total calcium (TCa) for the three components of the anion gap and albumin. On internal validation, it outperformed the popular method that corrects TCa for albumin alone (cTCa) in diagnosing low ICa. In this study, we sought to externally validate our ICa model in hospitalized COVID-19 positive patients. METHODS: We retrospectively studied all 200 patients with COVID-19 who were admitted to the State University of New York Downstate Medical Center between March 11th and April 30th 2020 and referred to the nephrology service for renal failure, and who had ICa measured on a venous blood gas within 25 min of a comprehensive metabolic panel. We compared the performance of the ICa model and cTCa in diagnosing low ICa by ROC analysis, and also examined the accuracy of the absolute values predicted by the two methods relative to measured ICa. RESULTS: On ROC analysis, the ICa model was better than cTCa (area under ROC curve: 0.872 [0.025] vs. 0.835 [0.028]; p = 0.045). The ICa model estimated ICa accurately, but the cTCa method seemed to overcorrect TCa, as a substantial number of patients with clearly normal cTCa values had low ICa. CONCLUSIONS: In an external validation cohort, the ICa model estimated ICa accurately and was better than cTCa in the diagnosis of low ICa. This finding can be useful in guiding direct ICa testing.

Opioids and Acute Kidney Injury.

Opioid use and misuse in the United States has been at epidemic proportions and is predicted to increase further in the setting of the Coronavirus disease 19 pandemic. Acute kidney injury is a condition associated with significant morbidity and increased mortality. We review the literature on the effect of opioids on kidney function and critically examine the association between opioid use and acute kidney injury and identify at-risk populations in whom opioids should be used with caution. We also discuss the role of biomarkers in elucidating this condition and propose preventive measures, novel therapeutic options, and research directions.