Colistin nephrotoxicity in the ICU: Is it different in the geriatric patients?

Novel method for determination of colistin sulfate in human plasma by high-performance liquid chromatography-tandem mass spectrometry and its clinical applications in critically ill patients

Colistin is a last-resort antibiotic used for treating infections caused by carbapenem-resistant Gram-negative bacteria, particularly in critically patients, nevertheless its therapeutic window is narrow, and requires monitoring. A determination method suitable for clinical detection is conducive to ensure its efficacy and safety of patients with severe infection. We developed and validated a concise and accurate high-performance liquid chromatography-tandem mass spectrometry method for the determination of colistin A and B in human plasma. We used a Kinetex C18 column (50 mm × 2.1 mm, 2.6 μm) with acetonitrile (containing 0.1% formic acid) as the protein precipitant and water (containing 0.2% formic acid and 5 mmol/L ammonium formate) - acetonitrile (containing 0.2% formic acid) as the gradient elution. The calibration curves were linear over concentration ranges of 0.06-4.00 μg/mL (colistin A) and 0.1-7.0 μg/mL (colistin B). The precision, accuracy, matrix effect, extraction recovery, and stability were all validated. This method was applied to the therapeutic drug monitoring for 50 critically ill patients. The trough, peak, and average steady-state concentrations of these patients were 0.8 ± 0.4, 1.4 ± 0.5, and 1.0 ± 0.4 μg/mL, respectively. And the concentrations of colistin in human plasma were closely related to the patient's renal function.

Dexmedetomidine may reduce the risk of acute kidney injury development in critically ill patients during colistin therapy

INTRODUCTION

Colistin is considered as a last resort therapy for multidrug-resistant gram-negative organisms. It is widely used despite the significant risk of nephrotoxicity. Experimental studies showed the nephroprotective effect of dexmedetomidine, a sedative agent, against colistin toxicity. This study was performed to show the possible nephroprotective effect of dexmedetomidine among critically ill patients who received colistin.

METHODS

Adult (>17 years) patients who were admitted to our surgical and medical intensive care unit (ICU) from March 2018 through March 2021, and who received colistin were included. Patients who receive Colistin therapy or intensive care unit follow-up of <72 h (discharge or death) and Acute kidney injury (AKI) or need hemodialysis prior to colistin therapy at the same hospitalization were excluded. AKI risk factors were examined by grouping patients with and without AKI. Patients, receiving colistin concomitantly with dexmedetomidine were also evaluated.

RESULTS

Of the 139 patients included, 27 (17.8%) patients received dexmedetomidine. Sixty-five patients (47%) had AKI, at a median 5 (4-7) days after the initiation of colistin. Older age, lower baseline estimated glomerular filtration rate, and vasopressor use were associated with a higher risk of AKI, while dexmedetomidine use was associated with a lower risk. In the multivariate regression model, dexmedetomidine use was independently associated with a lower risk of AKI development (OR 0.20 95% CI 0.07-0.59, p = 0.003).

CONCLUSION

In respect to these findings, dexmedetomidine may provide protection against AKI during colistin therapy in critically ill patients.

Prevalence of polymyxin-induced nephrotoxicity and its predictors in critically ill adult patients: A meta-analysis

BACKGROUND

Polymyxin-induced nephrotoxicity is a major safety concern in clinical practice due to long-term adverse outcomes and high mortality.

AIM

To conducted a systematic review and meta-analysis of the prevalence and potential predictors of polymyxin-induced nephrotoxicity in adult intensive care unit (ICU) patients.

METHODS

PubMed, EMBASE, the Cochrane Library and Reference Citation Analysis database were searched for relevant studies from inception through May 30, 2022. The pooled prevalence of polymyxin-induced nephrotoxicity and pooled risk ratios of associated factors were analysed using a random-effects or fixed-effects model by Stata SE ver. 12.1. Additionally, subgroup analyses and meta-regression were conducted to assess heterogeneity.

RESULTS

A total of 89 studies involving 12234 critically ill adult patients were included in the meta-analysis. The overall pooled incidence of polymyxin-induced nephrotoxicity was 34.8%. The pooled prevalence of colistin-induced nephrotoxicity was not higher than that of polymyxin B (PMB)-induced nephrotoxicity. The subgroup analyses showed that nephrotoxicity was significantly associated with dosing interval, nephrotoxicity criteria, age, publication year, study quality and sample size, which were confirmed in the univariable meta-regression analysis. Nephrotoxicity was significantly increased when the total daily dose was divided into 2 doses but not 3 or 4 doses. Furthermore, older age, the presence of sepsis or septic shock, hypoalbuminemia, and concomitant vancomycin or vasopressor use were independent risk factors for polymyxin-induced nephrotoxicity, while an elevated baseline glomerular filtration rate was a protective factor against colistin-induced nephrotoxicity.

CONCLUSION

Our findings indicated that the incidence of polymyxin-induced nephrotoxicity among ICU patients was high. It emphasizes the importance of additional efforts to manage ICU patients receiving polymyxins to decrease the risk of adverse outcomes.

Systematic review on estimated rates of nephrotoxicity and neurotoxicity in patients treated with polymyxins

BACKGROUND

Nephrotoxicity and neurotoxicity are commonly associated with polymyxin treatment; however, the emergence of multidrug-resistant Gram-negative bacteria with limited therapeutic options has resulted in increased use of polymyxins.

OBJECTIVES

To determine the rates of nephrotoxicity and neurotoxicity during polymyxin treatment and whether any factors influence these.

DATA SOURCES

Medline, Embase and Cochrane Library databases were searched on 2 January 2020.

STUDY ELIGIBILITY CRITERIA

Studies reporting nephrotoxicity and/or neurotoxicity rates in patients with infections treated with polymyxins were included. Reviews, meta-analyses and reports not in English were excluded.

PARTICIPANTS

Patients hospitalized with infections treated with systemic or inhaled polymyxins were included. For comparative analyses, patients treated with non-polymyxin-based regimens were also included.

METHODS

Meta-analyses were performed using a random-effects model; subgroup meta-analyses were conducted where data permitted using a mixed-effects model.

RESULTS

In total, 237 reports of randomized controlled trials, cohort and case-control studies were eligible for inclusion; most were single-arm observational studies. Nephrotoxic events in 35,569 patients receiving polymyxins were analysed. Overall nephrotoxicity rate was 0.282 (95% confidence interval (CI) 0.259-0.307). When excluding studies where >50% of patients received inhaled-only polymyxin treatment or nephrotoxicity assessment was by methods other than internationally recognized criteria (RIFLE, KDIGO or AKIN), the nephrotoxicity rate was 0.391 (95% CI 0.364-0.419). The odds of nephrotoxicity were greater with polymyxin therapies compared to non-polymyxin-based regimens (odds ratio 2.23 (95% CI 1.58-3.15); p < 0.001). Meta-analyses showed a significant effect of polymyxin type, dose, patient age, number of concomitant nephrotoxins and use of diuretics, glycopeptides or vasopressors on the rate of nephrotoxicity. Polymyxin therapies were not associated with a significantly different rate of neurotoxicity than non-polymyxin-based regimens (p 0.051). The overall rate of neurotoxicity during polymyxin therapy was 0.030 (95% CI 0.020-0.043).

CONCLUSIONS

Polymyxins are associated with a higher risk of nephrotoxicity than non-polymyxin-based regimens.

Polymyxin-induced nephrotoxicity and its predictors: a systematic review and meta-analysis of studies conducted using RIFLE criteria of acute kidney injury

Polymyxins are last-resort antibiotics re-emerged to treat infections caused by multidrug resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacterial infections. However, polymyxin-associated nephrotoxicity has become the main safety concern. Therefore, we conducted this systematic review and meta-analysis on polymyxin-induced nephrotoxicity and its predictors using studies conducted based on the validated RIFLE (Risk, Injury, Failure, Loss of Function and End-stage renal disease) criteria of acute kidney damage. Literature search was carried out through visiting legitimate databases and indexing services including PubMed, MEDLINE (Ovid®), EMBASE (Ovid®), and Scopus to retrieve relevant studies. Following screening and eligibility evaluation, relevant data were extracted from included studies and analyzed using STATA 15.0 and Rev-Man 5.3. Inverse variance method with random effects pooling model was used for the analysis of outcome measures at 95% confidence interval. Besides, meta-regression, meta-influence, and publication bias analyses were conducted. A total of 48 studies involving 6,199 adult patients aged ≥ 18 years were included for systematic review and meta-analysis. The pooled incidence of polymyxin-induced nephrotoxicity was found to be 45% (95% CI: 41- 49%; I² = 92.52%). Stratifying with RIFLE severity scales, pooled estimates of polymyxin-treated patients identified as 'risk', 'injury' and 'failure' were 17% (95% CI: 14-20%), 13% (95% CI: 11-15%), and 10% (95% CI: 9-11%), respectively. Besides, the pooled incidence of colistin-induced nephrotoxicity was about 48% (95% CI: 42-54%), whereas that of polymyxin B was 38% (95% CI: 32-44%). Likewise, colistin had 37% increased risk of developing nephrotoxicity compared to the polymyxin B treated cohorts (RR = 1.37, 95% CI: 1.13-1.67; I² = 57%). Older age (AOR = 1.03, 95% CI: 1.01-1.05), daily dose (AOR = 1.46, 95% CI: 1.09-1.96), underlying diabetes mellitus (AOR = 1.81, 95% CI: 1.25-2.63), and concomitant nephrotoxic drugs (AOR = 2.31, 95% CI: 1.79-3.00) were independent risk factors for polymyxin-induced nephrotoxicity. Patients with high serum albumin level were less likely (AOR = 0.69, 95% CI: 0.56-0.85] to experience nephrotoxicity compared to those with low albumin level. Despite the resurgence of these antibiotics for the chemotherapy of MDR/XDR-Gram-negative superbugs, the high incidence of nephrotoxicity has become a contemporary clinical concern. Being elderly, high daily dose, having underlying diseases such as diabetes, and use of concomitant nephrotoxic drugs were independent predictors of nephrotoxicity. Therefore, therapeutic drug monitoring should be done to these patients to outweigh the potential benefits of polymyxin therapy from its risk.

Colistin co-administration with other nephrotoxins: experience of teaching hospital of Latvia

Background Colistin is a potentially nephrotoxic antibiotic used for the management of multidrug-resistant bacterial infections in critically ill patients. Co-administration with other nephrotoxins was reported as a potentially modifiable risk factor of colistin acute kidney injury. Objective To establish the role of colistin dosing and co-medications in development of colistin kidney injury. Setting Community teaching hospital in Latvia. Method Adult patients from intensive care units with diagnosed Gram-negative bacterial infections, undergoing colistin treatment for longer than 72 h, and not receiving renal replacement therapy were included in this retrospective study. Main outcome measure Colistin nephrotoxicity was defined as an increase in the serum creatinine level by at least 50% from the baseline after ≥ 48 h. Results In 73 of 87 cases, Acinetobacter baumannii pneumonia was diagnosed. The nephrotoxicity rate was 27.6% with a median onset of 8 days. In 79% of the cases, colistin was co-administrated with at least one potentially nephrotoxic agent. The most used nephrotoxins were loop diuretics (44 cases), non-steroidal anti-inflammatory drugs (19 cases) and vancomycin (11 cases). The use of nephrotoxins was similar in patients with colistin nephrotoxicity (group-1) and without it (group-2). Carbapenems were more common in group-2 (37% vs 62%, p = 0.004) and a colistin loading dose of 9 MU in group-1 (87% vs 62%, p = 0.027). However, in the multifactor regression analysis, the protective role of carbapenems was not confirmed. Conclusion Potentially nephrotoxic agents are commonly co-administrated with colistin. This study failed to prove their role in the development of acute kidney injury.

Acute kidney injury following colistin treatment in critically-ill patients: may glucocorticoids protect?

Nephrotoxicity following colistin administration is common and factors alleviating nephrotoxicity are yet to be determined. We retrospectively evaluated outcomes of subjects who were treated with colistin (n = 133) and with antibiotics other than colistin (control, n = 133) in intensive care units. Acute kidney injury (AKI) occurred in 69.2% and 29.3% of patients in colistin and control groups, respectively (p < 0.001). In the colistin group, glucocorticoid exposure was more common in subjects who did not develop AKI (p < 0.001). This was not the case in the control group. In the colistin cohort, older age (per 10 years, odds ratio [OR] 1.41, 95% CI 1.05-1.91; p = 0.025), PPI use (OR 3.30, 95% CI 1.18-9.23; p = 0.023) and furosemide treatment (OR 2.66, 95% CI 1.01-6.98; p = 0.047) were independently associated with the development of AKI while glucocorticoid treatment (OR 0.23, 95% CI 0.10-0.53; p = 0.001) was independently associated with reduced risk of AKI. Mortality was observed in 74 patients in the colistin cohort (55.6%). A higher APACHE-II score (OR 1.17, 95% CI 1.08-1.26; p < 0.001) was independently associated with mortality while a higher serum albumin level (per 1 g/dL increase, OR 0.20, 95% CI 0.070-0.60; p = 0.004) was associated with a lower risk of mortality. In conclusion, glucocorticoid exposure is associated with a lower risk of AKI caused by colistin therapy in critically-ill patients. Prospective studies are needed to confirm these findings and determine the optimal type, dose and duration of glucocorticoid therapy.

Complete Genome and Plasmid Sequences of Seven Isolates of Salmonella enterica subsp. enterica Harboring the mcr-1 Gene Obtained from Food in China

Seven Salmonella enterica subsp. enterica isolates were identified as carrying the mcr-1 gene, by using a real-time fluorescence quantitative PCR method, from a total of 2,558 isolates which were cultured from various food origins in China between 2011 and 2016. Few complete genomes of Salmonella strains harboring the mcr-1 gene have been reported to date, so we report here the complete genome and plasmid sequences of all of these isolates to provide useful references for understanding the prevalence of foodborne Salmonella enterica subsp. enterica isolates carrying mcr-1.