<i>N</i>-acetylcysteine for the prevention of contrast-induced nephropathy in patients with pre-existing renal insufficiency or diabetes: a systematic review and meta-analysis

<div><p></p><p><i>Purpose</i>: To identify benefit of <i>N</i>-acetylcysteine (NAC) on patients with pre-existing renal insufficiency or diabetes. <i>Background</i>: NAC administration is a common method for prevention of contrast-induced nephropathy (CIN). Nevertheless, its benefit on patients with pre-existing renal insufficiency or diabetes remains uncertain and controversial. <i>Methods:</i> Randomized controlled trials (RCTs) to evaluate the efficacy of NAC for the prevention of CIN in patients with pre-existing renal insufficiency or diabetes were searched from the databases of MEDLINE, EMBASE, and Cochrane library. Pooled odds ratio (OR) with 95% confidence interval (95% CI) were calculated using fixed-effects model by the Mantel–Haenszel test. <i>Results</i>: Twenty RCTs involving 3466 subjects (1756 assigned to NAC and 1710 assigned to the control) were included in the pre-existing renal dysfunction group. Pooled analysis suggested a significant reduction in CIN among this group (OR, 0.76; 95% CI, 0.61–0.93; <i>p</i> = 0.008). However, the nine trials comparing NAC versus control among patients with diabetes (NAC, 367 subjects; control, 358 subjects) showed no benefit of NAC for prevention of CIN (OR = 0.87; 95% CI, 0.58–1.30; <i>p</i> = 0.50). No significant heterogeneity was detected (<i>p</i> = 0.07; <i>I</i>² = 34% for the group of pre-existing renal dysfunction; <i>p</i> = 0.40; <i>I</i>² = 5% for the group of diabetes). <i>Conclusion</i>: Our results suggest that NAC decreases the incidence of contrast-induced nephropathy among patients with pre-existing renal insufficiency. The benefit was not existed in patients with diabetes.</p></div

The Volume Ratio of Ground Glass Opacity in Early Lung CT Predicts Mortality in Acute Paraquat Poisoning

<div><p>Background</p><p>Pulmonary injury is the main cause of death in acute paraquat (PQ) poisoning. However, whether quantitative lung computed tomography (CT) can be useful in predicting the outcome of PQ poisoning remains unknown. We aimed to identify early findings of quantitative lung CT as predictors of outcome in acute PQ poisoning.</p><p>Methods</p><p>Lung CT scanning (64-slide) and quantitative CT lesions were prospectively measured for patients after PQ intoxication within 5 days. The study outcome was mortality during 90 days follow-up. Survival curves were derived by the Kaplan-Meier method, and mortality risk factors were analyzed by the forward stepwise Cox regression analysis.</p><p>Results</p><p>Of 97 patients, 41 (42.3%) died. Among the eight different types of lung CT findings which appeared in the first 5-day of PQ intoxication, four ones discriminated between survivors and non-survivors including ground glass opacity (GGO), consolidation, pneumomediastinum and “no obvious lesion”. With a cutoff value of 10.8%, sensitivity of 85.4% and specificity of 89.3%, GGO volume ratio is better than adopted outcome indicators in predicting mortality, such as estimated amount of PQ ingestion, plasma or urine PQ concentration, acute physiology and chronic health evaluation (APACHE) II and sequential organ failure assessment (SOFA) scores. GGO volume ratios above 10.8% were associated with increased mortality (hazard ratio, 5.82; 95% confidence interval, 4.77-7.09; <i>P</i> < 0.001).</p><p>Conclusions</p><p>The volume ratio of GGO exceeding 10.8% is a novel, reliable and independent predictors of outcome in acute PQ poisoning.</p></div

Cox Proportional Hazards Models for Mortality Prediction of PQ Poisoning.

<p><i>Definition of abbreviations</i>: PQ = paraquat; HR = harzard ratio; N/A = not applicable.</p><p>Note: * indicates variables were categorical using the presence of CT finding as a dichotomous variable; other variables were categorical according whether lesion volume ratio was above or below the optimal cutoff point.</p><p>Cox Proportional Hazards Models for Mortality Prediction of PQ Poisoning.</p

Kaplan-Meier survival curves of 97 paraquat poisoned cases stratified according to levels of GGO volume ratios within the first 5-day period.

<p>Patients were categorized into three groups based on quartile levels of GGO volume ratios. Comparisons between curves showing difference with statistical significance (P < 0.05) are indicated.</p

Kaplan-Meier survival curves of 97 paraquat poisoned cases stratified according to different CT findings within the first 5-day period.

<p>Patients were categorized into two groups based on whether or not they presented the specific CT finding. The P values were derived by log-rank test.</p

Comparison of Predictors for Mortality of PQ Poisoning.

<p><i>Definition of abbreviations</i>: PQ = paraquat; AUC = area under a receiver operator curve; Sen = sensitivity; Spe = specificity; PPV = positive predictive value; NPV = negative predictive value; ACC = Accuracy; APACHEII = Acute Physiology and Chronic Health Evaluation; SOFA = Sequential Organ Failure Assessment;</p><p>Note: amount of PQ ingestion, plasma PQ concentration, and urine PQ concentration were collected on admission; other parameters were the peak values within 5 days following intake of paraquat.</p><p>Comparison of Predictors for Mortality of PQ Poisoning.</p

Demographic and Clinical Data of Patients during the first 5-day of PQ Poisoning.

<p><i>Definition of abbreviations</i>: PQ = paraquat; APACHEII = Acute Physiology and Chronic Health Evaluation; SOFA = Sequential Organ Failure Assessment; continuous variable are presented as means ± SD or median (interquartile range) and categorical variable is presented as no. (%).</p><p>Note: the values of Symptom, Scoring, renal function, liver function and arterial blood gases were the peak values during the first 5-day.</p><p>Demographic and Clinical Data of Patients during the first 5-day of PQ Poisoning.</p

The receiver operating characteristic (ROC) curves constructed for outcome prediction by amount of paraquat (PQ) ingestion, plasma and urine concentrations of PQ, scores of Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA), as well as volume ratio of Ground glass opacity and consolidation following PQ poisoning.

<p>The receiver operating characteristic (ROC) curves constructed for outcome prediction by amount of paraquat (PQ) ingestion, plasma and urine concentrations of PQ, scores of Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA), as well as volume ratio of Ground glass opacity and consolidation following PQ poisoning.</p

Flow chart.

<p>Flow chart.</p

Eight Lung CT Findings during the First 5 Days after PQ Intoxication.

<p><i>Definition of abbreviations</i>: PQ = paraquat; OR = odds ratio.</p><p>Eight Lung CT Findings during the First 5 Days after PQ Intoxication.</p