Dynamic prediction of mortality in COVID-19 patients in the intensive care unit: A retrospective multi-center cohort study.

Background: The COVID-19 pandemic continues to overwhelm intensive care units (ICUs) worldwide, and improved prediction of mortality among COVID-19 patients could assist decision making in the ICU setting. In this work, we report on the development and validation of a dynamic mortality model specifically for critically ill COVID-19 patients and discuss its potential utility in the ICU. Methods: We collected electronic medical record (EMR) data from 3222 ICU admissions with a COVID-19 infection from 25 different ICUs in the Netherlands. We extracted daily observations of each patient and fitted both a linear (logistic regression) and non-linear (random forest) model to predict mortality within 24 h from the moment of prediction. Isotonic regression was used to re-calibrate the predictions of the fitted models. We evaluated the models in a leave-one-ICU-out (LOIO) cross-validation procedure. Results: The logistic regression and random forest model yielded an area under the receiver operating characteristic curve of 0.87 [0.85; 0.88] and 0.86 [0.84; 0.88], respectively. The recalibrated model predictions showed a calibration intercept of -0.04 [-0.12; 0.04] and slope of 0.90 [0.85; 0.95] for logistic regression model and a calibration intercept of -0.19 [-0.27; -0.10] and slope of 0.89 [0.84; 0.94] for the random forest model. Discussion: We presented a model for dynamic mortality prediction, specifically for critically ill COVID-19 patients, which predicts near-term mortality rather than in-ICU mortality. The potential clinical utility of dynamic mortality models such as benchmarking, improving resource allocation and informing family members, as well as the development of models with more causal structure, should be topics for future research.

Fournier's gangrene as first presentation of promyelocytic leukemia.

A 50-year-old male is described who presented with Fournier's gangrene as what is probably the first manifestation of a newly diagnosed acute myelogenous leukemia (AML), promyelocytic type or variant type M3 according to the FAB classification. Despite aggressive fluid resuscitation, tuned infusion of vasoactive drugs, appropriate antibiotics and extensive surgical debridement, the patient died within 24 h as a result of irreversible septic shock.

Clozapine-induced agranulocytosis: a case report. Immunopathophysiological considerations.

A 46-year-old woman is described with a clozapine-induced agranulocytosis. She was treated with a broad-spectrum antibiotic and supportive care was provided with granulocyte colony-stimulating factor (G-CSF). Immune-mediated mechanisms of clozapine-induced agranulocytosis and the role of haematopoietic growth factors are discussed.

ACE inhibitors and the kidney. A risk-benefit assessment.

ACE inhibitors effectively reduce systemic vascular resistance in patients with hypertension, heart failure or chronic renal disease. This antihypertensive efficacy probably accounts for an important part of their long term renoprotective effects in patients with diabetic and non-diabetic renal disease. The renal mechanisms underlying the renal adverse effects of ACE inhibitors--intrarenal efferent vasodilation with a consequent fall in filtration pressure--are held to be involved in their renoprotective effects as well. The fall in filtration pressure presumably contributes to the antiproteinuric effect as well as to long term renoprotection. The former is suggested by the positive correlation between the fall in filtration fraction and the reduction in proteinuria found during ACE inhibition. The latter is suggested by the correlation between the (slight) reduction in glomerular filtration rate at onset of therapy and a more favourable course of renal function in the long term. Such a fall in filtration rate at the onset of ACE inhibitor treatment is reversible after withdrawal, and can be considered the trade-off for long term renal protection in patients with diabetic and nondiabetic chronic renal disease. In conditions in which glomerular filtration is critically dependent on angiotensin II-mediated efferent vascular tone (such as a post-stenotic kidney, or patients with heart failure and severe depletion of circulating volume), ACE inhibition can induce acute renal failure, which is reversible after withdrawal of the drug. Systemic and renal haemodynamic effects of ACE inhibition, both beneficial and adverse, are potentiated by sodium depletion. Consequently, sodium repletion contributes to the restoration of renal function in patients with ACE inhibitor-induced acute renal failure. Our the other hand, co-treatment with diuretics and sodium restriction can improve therapeutic efficacy in patients in whom the therapeutic response of blood pressure or proteinuria is insufficient. Patients at the greatest risk for renal adverse effects (those with heart failure, diabetes mellitus and/or chronic renal failure) also can expect the greatest benefit. Therefore, ACE inhibitors should not be withheld in these patients, but dosages should be carefully titrated, with monitoring of renal function and serum potassium levels.

Relapse Pneumocystis carinii pneumonitis and adverse reaction to current therapy in patients with AIDS: trimetrexate as an alternative.

This is a case report of a 31-yr-old homosexual male with AIDS, admitted to our clinic with a relapse P. carinii pneumonitis (PCP) and a previous history of severe adverse reactions to currently used therapy. He was treated successfully with trimetrexate (TMTX), a dihydrofolate reductase inhibitor combined with leucovorin rescue. Adverse reactions, current therapy and prophylaxis of PCP in AIDS are discussed.