Higher incidence of acute kidney injury in patients treated with piperacillin/tazobactam than in patients treated with cefepime: a single-center retrospective cohort study

Drug Utilization Evaluation and Impact of Pharmacist Interventions on Optimization of Piperacillin/Tazobactam Use: A Retrospective Analysis and Prospective Audit

(1) Background: Piperacillin/tazobactam is a broad-spectrum antimicrobial encompassing most Gram-positive and Gram-negative aerobic and anaerobic bacteria. The inappropriate use of such broad-spectrum antibiotics is an important contributor to the rising rates of antimicrobial drug resistance worldwide. Drug utilization evaluation studies and pharmacists' interventions are vital to assess, develop, and promote the rational use of antibiotics. This drug utilization study aimed to evaluate the current utilization practice of piperacillin/tazobactam in a hospital setting and assess the impact of pharmacist intervention in improving its appropriate use. (2) Methodology: In this study, we used a retrospective cohort and a prospective cohort, a cross-sectional, observational method. It included a retrospective (Cycle A/pre-intervention-CycA) phase followed by an educational interventional phase conducted by the pharmacists. During the 2 months of educational intervention, pharmacists used several methods, including workshops, lectures, oral presentations, and the development and reinforcement of clinical pathways to promote the judicious use of piperacillin/tazobactam. This was followed by a prospective (Cycle B/post-intervention-CycB) phase to improve piperacillin/tazobactam usage appropriateness. The appropriateness criteria for this drug utilization evaluation were established based on antimicrobial guidelines, the published literature, the institutional antibiogram, consultation from the antimicrobial stewardship committee, and the product monograph (Tazocin). The appropriateness of CycA and CycB patients was compared using the measurable elements, including indication and dose based on renal function, timely order for cultures, de-escalation, and use of extended infusion protocol. (3) Results: The study population comprised 100 patients in both CycA and CycB. The mean age of the patients was 66.28 ± 16.15 and 67.35 ± 17.98, and the ratios of men to women were found to be 49:51 and 61:39 in CycA and CycB, respectively. It was observed that inappropriate usage was high in CycA patients, and the appropriateness was improved in CycB patients. A total of 31% of inappropriate empirical broad-spectrum use was found in CycA, and it was reduced to 12% in CycB patients. The transition of appropriateness was observed in all measurable criteria, which includes the optimized dose according to the renal function (CycA = 49% to CycB = 94%), timely bacterial culture orders (CycA = 47% to CycB = 74%), prompt de-escalation (CycA = 31% to CycB = 53%), and adherence to extended infusion institutional guidelines (CycA = 34% to CycB = 86%). (4) Conclusions: The study highlighted important aspects of inappropriate piperacillin/tazobactam use. This can be considerably improved by proper education and timely interventions based on the pharmacists' vigilant approach. The study results emphasized the need for surveillance of piperacillin/tazobactam usage by conducting similar drug utilization evaluations and practice to improve quality and safety in healthcare organizations globally.

Underdiagnosed CKD in Geriatric Trauma Patients and Potent Prevention of Renal Impairment from Polypharmacy Risks through Individual Pharmacotherapy Management (IPM-III)

The aging global patient population with multimorbidity and concomitant polypharmacy is at increased risk for acute and chronic kidney disease, particularly with severe additional disease states or invasive surgical procedures. Because from the expertise of more than 58,600 self-reviewed medications, adverse drug reactions, drug interactions, inadequate dosing, and contraindications all proved to cause or exacerbate the worsening of renal function, we analyzed the association of an electronic patient record- and Summaries of Product Characteristics (SmPCs)-based comprehensive individual pharmacotherapy management (IPM) in the setting of 14 daily interdisciplinary patient visits with the outcome: further renal impairment with reduction of eGFR ≥ 20 mL/min (redGFR) in hospitalized trauma patients ≥ 70 years of age. The retrospective clinical study of 404 trauma patients comparing the historical control group (CG) before IPM with the IPM intervention group (IG) revealed a group-match in terms of potential confounders such as age, sex, BMI, arterial hypertension, diabetes mellitus, and injury patterns. Preexisting chronic kidney disease (CKD) > stage 2 diagnosed as eGFR < 60 mL/min/1.73 m² on hospital admission was 42% in the CG versus 50% in the IG, although in each group only less than 50% of this was coded as an ICD diagnosis in the patients' discharge letters (19% in CG and 21% in IG). IPM revealed an absolute risk reduction in redGFR of 5.5% (11 of 199 CG patients) to 0% in the IPM visit IG, a relative risk reduction of 100%, NNT 18, indicating high efficacy of IPM and benefit in improving outcomes. There even remained an additive superimposed significant association that included patients in the IPM group before/beyond the 14 daily IPM interventions, with a relative redGFR risk reduction of 0.55 (55%) to 2.5% (5 of 204 patients), OR 0.48 [95% CI 0.438-0.538] (p < 0.001). Bacteriuria, loop diuretics, allopurinol, eGFR ≥ 60 mL/min/1.73 m², eGFR < 60 mL/min/1.73 m², and CKD 3b were significantly associated with redGFR; of the latter, 10.5% developed redGFR. Further multivariable regression analysis adjusting for these and established risk factors revealed an additive, superimposed IPM effect on redGFR with an OR 0.238 [95% CI 0.06-0.91], relative risk reduction of 76.2%, regression coefficient -1.437 including patients not yet visited in the IPM period. As consequences of the IPM procedure, the IG differed from the CG by a significant reduction of NSAIDs (p < 0.001), HCT (p = 0.028) and Würzburger pain drip (p < 0.001), and significantly increased prescription rate of antibiotics (p = 0.004). In conclusion, (1) more than 50% of CKD in geriatric patients was not pre-recognized and underdiagnosed, and (2) the electronic patient records-based IPM interdisciplinary networking strategy was associated with effective prevention of further periinterventional renal impairment and requires obligatory implementation in all elderly patients to urgently improve patient and drug safety.

Protocol and statistical analysis plan for the Antibiotic Choice On ReNal outcomes (ACORN) randomised clinical trial

INTRODUCTION

Antibiotics are time-critical in the management of sepsis. When infectious organisms are unknown, patients are treated with empiric antibiotics to include coverage for gram-negative organisms, such as antipseudomonal cephalosporins and penicillins. However, in observational studies, some antipseudomonal cephalosporins (eg, cefepime) are associated with neurologic dysfunction while the most common antipseudomonal penicillin (piperacillin-tazobactam) is associated with acute kidney injury (AKI). No randomised control trials have compared these regimens. This manuscript describes the protocol and analysis plan for a trial designed to compare the effects of antipseudomonal cephalosporins and antipseudomonal penicillins among acutely ill patients receiving empiric antibiotics.

METHODS AND ANALYSIS

The Antibiotic Choice On ReNal outcomes trial is a prospective, single-centre, non-blinded randomised trial being conducted at Vanderbilt University Medical Center. The trial will enrol 2500 acutely ill adults receiving gram-negative coverage for treatment of infection. Eligible patients are randomised 1:1 to receive cefepime or piperacillin-tazobactam on first order entry of a broad-spectrum antibiotic covering gram-negative organisms. The primary outcome is the highest stage of AKI and death occurring between enrolment and 14 days after enrolment. This will be compared between patients randomised to cefepime and randomised to piperacillin-tazobactam using an unadjusted proportional odds regression model. The secondary outcomes are major adverse kidney events through day 14 and number of days alive and free of delirium and coma in 14 days after enrolment. Enrolment began on 10 November 2021 and is expected to be completed in December 2022.

ETHICS AND DISSEMINATION

The trial was approved by the Vanderbilt University Medical Center institutional review board (IRB#210591) with a waiver of informed consent. Results will be submitted to a peer-reviewed journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

NCT05094154.

Risk of Acute Kidney Injury and Fracture-Related Infection After Antibiotic Prophylaxis With Piperacillin-Tazobactam in Open Fractures

OBJECTIVES

To evaluate the effects of prophylactic piperacillin-tazobactam (PT) on inpatient acute kidney injury (AKI) and fracture-related infection (FRI) in patients with open fractures.

SETTING

The study was conducted at a Level 1 trauma center.

PATIENTS

We reviewed 358 Gustilo-Anderson type II and III open fractures at our institution from January 2013 to December 2017.

INTERVENTION

Administration of PT (the PT group) or antibiotics other than PT (the historical control group) during the first 48 hours of arrival for open fracture antibiotic prophylaxis.

MAIN OUTCOME MEASUREMENTS

The main outcome measurements were rates of inpatient AKI and FRI within six months after definitive fixation.

RESULTS

There were 176 patients in the PT group and 182 patients in the historical control group. The PT group had worse American Society of Anesthesiologists class ( P = 0.004) and injury severity scores ( P < 0.001), a higher average number of debridements before closure/coverage ( P = 0.043), and higher rates of gross soil contamination ( P = 0.049) and staged procedures ( P = 0.008) compared with the historical control group.There was no difference in the rate of AKI between the PT and historical control groups (5.7% vs. 2.7%, P = 0.166) nor when stratified by Gustilo-Anderson fracture classification (type II: 5.8% vs. 3.6%, P = 0.702; type III: 5.6% vs. 2.0%, P = 0.283). There was no significant difference in the rate of FRI between the PT and historical control groups (23.6% vs. 19.6%, P = 0.469).

CONCLUSION

The use of PT in prophylactic antimicrobial treatment in patients with Gustilo-Anderson type II and III open fractures does not increase the rate of AKI or FRI. We believe PT can be used as an effective monotherapy in these patients without an increased risk of renal injury, but future investigations are necessary.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Broad vs Narrow Spectrum Antibiotics in Common Bile Duct Stones: A Post Hoc Analysis of an Eastern Association for the Surgery of Trauma Multicenter Study

BACKGROUND

Antimicrobial guidance for common bile duct stones during the perioperative period is limited. We sought to examine the effect of broad-spectrum (BS) vs narrow-spectrum (NS) antibiotics on surgical site infections (SSIs) in patients with common bile duct stones undergoing same-admission cholecystectomy.

STUDY DESIGN

We performed a post hoc analysis of a prospective, observational, multicenter study of patients undergoing same-admission cholecystectomy for choledocholithiasis and/or acute biliary pancreatitis between 2016 and 2019. We excluded patients with cholangitis, perforated cholecystitis, and nonbiliary infections on admission. Patients were divided based on receipt of BS or NS antibiotics. Our primary outcome was the incidence of SSIs, and secondary outcomes included hospital length of stay, acute kidney injury (AKI), and 30-day readmission for SSI.

RESULTS

The cohort had 891 patients: 51.7% (n= 461) received BS antibiotics and 48.3% (n = 430) received NS antibiotics. Overall antibiotic duration was longer in the BS group than in the NS group (6 vs 4 d, p = 0.01); however, there was no difference in rates of SSI (0.9% vs 0.5%, p = 0.7) or 30-day readmission for SSI (1.1% vs 1.2%, p = 1.0). Hospital length of stay was significantly longer in the BS group (p < 0.001) as were rates of AKI (5% vs 1.4%, p = 0.001). On multivariable regression, BS antibiotic use was a risk factor for AKI (adjusted odds ratio 2.8, 95% CI 1.16 to 7.82, p = 0.02).

CONCLUSION

The incidence of SSI and 30-day readmission for SSI was similar between antibiotic groups. However, BS antibiotic use was associated with a longer hospitalization and greater likelihood of AKI.

Lowered Risk of Nephrotoxicity through Intervention against the Combined Use of Vancomycin and Tazobactam/Piperacillin: A Retrospective Cohort Study

The combined use of vancomycin (VCM) and tazobactam/piperacillin (TAZ/PIPC) is a major risk factor for nephrotoxicity. We sought to evaluate interventions against the combined use of VCM and TAZ/PIPC. This retrospective cohort study involved patients who considered the combined use of VCM and TAZ/PIPC as a treatment. Patients that had either or both antimicrobials replaced were assigned to the intervention group, whereas those who were continued on combination therapy were assigned to the comparison group. The primary endpoint was the incidence of acute kidney injury (AKI). The survival rate of patients on day 30 was evaluated as the secondary endpoint. The comparison and intervention groups were composed of 65 and 68 patients, respectively, and the incidence rates of AKI were 44.6% and 17.6%, respectively. Cox proportional hazard analysis identified the intervention as the only independent factor against AKI development, with a hazard ratio of 0.282 (95% confidence interval [CI], 0.141 to 0.565). For the incidence of AKI of grade greater than 1, the hazard ratio was 0.114 (95% CI, 0.025 to 0.497). The survival rates on day 30 in the comparison and intervention groups were 92.3% and 91.2%, respectively, with a relative risk of 0.988 (95% CI, 0.892 to 1.094). The trough VCM concentration was not associated with the incidence of AKI in patients receiving the combination therapy. This study demonstrated that intervention against the combined use of VCM and TAZ/PIPC can lower the risk of nephrotoxicity. IMPORTANCE The combined use of vancomycin (VCM) and tazobactam/piperacillin (TAZ/PIPC) is a major risk factor for nephrotoxicity. We retrospectively evaluated interventions against the combined use of VCM and TAZ/PIPC. Patients for whom either or both antimicrobials were replaced were assigned to the intervention group (65 patients), whereas those who were continued on combination therapy were assigned to the comparison group (68 patients). The primary endpoint was the incidence of acute kidney injury (AKI). The incidence rates of AKI in the intervention and comparison groups were 44.6% and 17.6%, respectively. Cox proportional hazard analysis identified intervention as the only independent factor against AKI development, with a hazard ratio of 0.282 (95% confidence interval [CI], 0.141 to 0.565). In conclusion, this study demonstrated that intervention against the combined use of VCM and TAZ/PIPC can lower the risk of nephrotoxicity.

Risk factors for acute kidney injury in vancomycin and piperacillin/tazobactam combination therapy: A retrospective study

INTRODUCTION

Combined use of vancomycin (VCM) and piperacillin/tazobactam (PIPC/TAZ) has been reported to increase the incidence of acute kidney injury (AKI). However, the risk factors associated with AKI after VCM and PIPC/TAZ (VPT) administration have not yet been identified. Therefore, we retrospectively assessed patients treated with VPT to investigate the risk factors for AKI development.

METHODS

The study involved patients who were treated with VPT from January 1, 2016 to March 31, 2020. The patients were divided into the AKI or non-AKI group. The clinical characteristics of patients and antimicrobial therapy were compared between the groups. Their association with AKI risk was evaluated using multivariate logistic regression analysis.

RESULTS

In total, 182 patients were included, with 118 in the non-AKI group and 64 in the AKI group. Therefore, the incidence of AKI was 35.2 %. The initiation of VPT combination therapy on the same day and concomitant use of vasopressors were associated with an increased risk of AKI (odds ratio [OR] 2.55, 95 % confidential interval [CI] 1.20-5.44 and OR 3.22, 95 % CI 1.31-7.89, respectively).

CONCLUSION

Our findings suggest that the concomitant use of vasopressors and initiating VPT combination therapy on the same day are likely risk factors for AKI development.

Nephrotoxicity of teicoplanin-based combination therapy: focus on piperacillin/tazobactam and other anti-pseudomonal β-lactams

BACKGROUND

The concurrent use of vancomycin and piperacillin/tazobactam increases the risk of acute kidney injury (AKI) compared with vancomycin use with other anti-pseudomonal β-lactams (OAPBs). Teicoplanin is a glycopeptide antibiotic with lower nephrotoxicity than that of vancomycin. Whether the concomitant use of teicoplanin and piperacillin/tazobactam also increases the risk of AKI remains unknown.

OBJECTIVES

To evaluate the AKI risk between teicoplanin-piperacillin/tazobactam and teicoplanin-OAPBs.

METHODS

This was a retrospective, propensity score-matched cohort study. Adult patients receiving teicoplanin-based combination therapy were included. OAPBs included cefepime, cefoperazone/sulbactam, ceftazidime, doripenem, imipenem/cilastatin and meropenem. Propensity score matching was performed to balance demographic and confounding factors. The primary endpoint was AKI during combination therapy.

RESULTS

After propensity score matching, 954 patients (teicoplanin-piperacillin/tazobactam: teicoplanin-OAPBs, 1:3 matched, 243 pairs in total) were included for analysis. The mean age was 66.3 years in the matched cohort and 17.1% of patients had shock. Use of nephrotoxic medications (45.7% versus 48.7%) and baseline renal function (78.88 ± 31.26 versus 81.05 ± 31.53 mL/min/1.73 m2) were similar in the two groups. The median teicoplanin dose was 10.7 mg/kg in both groups. The groups did not differ significantly in terms of AKI risk (14.8% versus 14.2%, P = 0.815). However, the time to AKI appeared shorter in the teicoplanin-piperacillin/tazobactam group (4.64 ± 2.33 versus 6.29 ± 4.72 days, P = 0.039).

CONCLUSIONS

The combination of teicoplanin and piperacillin/tazobactam was not associated with an increased risk of AKI compared with teicoplanin and OAPBs.

Personalized Piperacillin Dosing for the Critically Ill: A Retrospective Analysis of Clinical Experience with Dosing Software and Therapeutic Drug Monitoring to Optimize Antimicrobial Dosing

Optimization of antibiotic dosing is a treatment intervention that is likely to improve outcomes in severe infections. The aim of this retrospective study was to describe the therapeutic exposure of steady state piperacillin concentrations (c_PIP) and clinical outcome in critically ill patients with sepsis or septic shock who received continuous infusion of piperacillin with dosing personalized through software-guided empiric dosing and therapeutic drug monitoring (TDM). Therapeutic drug exposure was defined as c_PIP of 32–64 mg/L (2–4× the ‘MIC breakpoint’ of Pseudomonas aeruginosa). Of the 1544 patients screened, we included 179 patients (335 serum concentrations), of whom 89% achieved the minimum therapeutic exposure of >32 mg/L and 12% achieved potentially harmful c_PIP > 96 mg/L within the first 48 h. Therapeutic exposure was achieved in 40% of the patients. Subsequent TDM-guided dose adjustments significantly enhanced therapeutic exposure to 65%, and significantly reduced c_PIP > 96 mg/L to 5%. Mortality in patients with c_PIP > 96 mg/L (13/21; 62%) (OR 5.257, 95% CI 1.867–14.802, p = 0.001) or 64–96 mg/L (30/76; 45%) (OR 2.696, 95% CI 1.301–5.586, p = 0.007) was significantly higher compared to patients with therapeutic exposure (17/72; 24%). Given the observed variability in critically ill patients, combining the application of dosing software and consecutive TDM increases therapeutic drug exposure of piperacillin in patients with sepsis and septic shock.

Vancomycin-Associated Tubular Casts and Vancomycin Nephrotoxicity

Introduction

Vancomycin nephrotoxicity is frequent and may be due to drug-induced acute tubular necrosis (ATN) or tubulointerstitial nephritis (TIN). Vancomycin-associated tubular cast (VTC) was recently described and may represent a novel cause of vancomycin nephrotoxicity. However, much is still unknown about VTC.

Materials and Methods

Thirty-seven kidney biopsy specimens from patients who were treated with vancomycin and developed acute kidney injury (AKI) were found among a total of 4673 biopsy samples between 2010 and 2019. These biopsy specimens were subjected to light microscopy, immunofluorescence, electron microscopy, and immunolocalization for vancomycin, uromodulin, myoglobin, tubular segment–specific markers, and examined for VTCs. The findings were correlated with the clinical course.

Results

VTCs displayed precipitated vancomycin casts in a background of uromodulin; the casts were limited to the distal tubules, and always associated with a background of more diffuse renal injury (ATN or TIN). The diagnosis of vancomycin nephrotoxicity was made in in 28 of 37 patients. VTC was noted in 25 of 28 biopsy samples from patients diagnosed with vancomycin nephrotoxicity and in one of nine biopsy samples from patients without this diagnosis. Vancomycin nephrotoxicity was diagnosed in 25 of 26 patients whose biopsy specimens showed VTC, but in only 3 of 11 patients without VTC in the biopsy samples.

Conclusions

VTC displays a characteristic morphologic profile amenable to ready recognition in biopsy specimens. It results from coprecipitation of vancomycin and uromodulin. It facilitates the biopsy diagnosis of vancomycin nephrotoxicity. It may have a nephrotoxic effect superimposing on and independent from the ATN or interstitial nephritis in the pathogenesis of vancomycin nephrotoxicity.

Validation and Application of an HPLC-UV Method for Routine Therapeutic Drug Monitoring of Cefiderocol

Cefiderocol is a new siderophore cephalosporin approved for the treatment of multidrug resistant bacteria including activity against carbapenem-resistant Enterobacterales and Pseudomonas aeruginosa. As cephalosporins are known for their high pharmacokinetic variability in critically ill patients, cefiderocol therapeutic drug monitoring might become a valuable tool. Therefore, we aimed to develop and validate a simple, rapid, cost-effective high performance liquid chromatography (HPLC) method for the quantification of cefiderocol in serum. Samples were treated for protein precipitation followed by chromatographic separation on a reverse phase column (HPLC C-18) with gradient elution of the mobile phase. Cefiderocol was detected via UV absorption and quantification was performed with the internal standard (metronidazole) method. The calibration range showed linearity from 4 to 160 mg/L. The intra and interday precision was less than 10% with a recovery rate of 81%. The method was successfully used for the analysis of subsequent serum samples of critically ill patients and showed good performance in monitoring serum levels and optimizing antibiotic therapy.

Safety considerations of current drug treatment strategies for nosocomial pneumonia

Introduction: Nosocomial pneumonia unfortunately remains a frequent event for which appropriate antibiotic treatment is central to improving outcomes. Physicians must choose an early and appropriate empirical treatment, basing their decision on the safety profile and possible side effects. Areas covered: In this review, we analyzed the safety profiles of the most common antimicrobials for treating nosocomial pneumonia. Beta-lactams are used most often for these infections, with a high percentage (6% to 25%) of patients reporting allergy or hypersensitivity reactions; however, exhaustive evaluation is key because it seems possible to de-label as many as 90% by proper assessment. Combinations including a beta-lactam are recommended in patients with risk factors for drug-resistant microorganisms and septic shock. Although aminoglycosides are safe for 3-5 days of therapy, renal function should be monitored. Fluoroquinolones must also be used with care given the risk of collagen degradation and cardiovascular events, mainly aneurysm or aortic dissection. Linezolid or vancomycin are both viable for the treatment of methicillin-resistant Staphylococcus aureus, but linezolid seems to be the superior option. Antibiotic stewardships programs must be developed for each center. Expert opinion: Choosing the most appropriate antimicrobial based on information from national and international guidelines, local microbiology data, and stewardship programs may reduce the use of broad-spectrum antibiotics. Daily assessment for the emergence of adverse events related to antimicrobial use is essential.

Risk of acute kidney injury and Clostridioides difficile infection with piperacillin/tazobactam, cefepime and meropenem with or without vancomycin

BACKGROUND

Empiric antimicrobial therapy for healthcare-acquired infections often includes vancomycin plus an antipseudomonal beta-lactam (AP-BL). These agents vary in risk for adverse events, including acute kidney injury (AKI) and Clostridium difficile infection (CDI). Studies have only examined these risks separately; thus, our objective was to simultaneously evaluate AKI and CDI risks with AP-BL in the same patient cohort.

METHODS

This retrospective cohort study included 789,200 Veterans Health Administration medical admissions from July 1, 2010 through June 30, 2016. The antimicrobials examined were vancomycin, cefepime, piperacillin/tazobactam, and meropenem. Cox proportional hazards regression was used to contrast risks for AKI and CDI across individual target antimicrobials and vancomycin combination therapies, including adjustment for known confounders.

RESULTS

With respect to the base rate of AKI among patients who did not receive a target antibiotic (4.6%), the adjusted hazards ratios for piperacillin/tazobactam, cefepime, and meropenem were 1.50 (95% CI: 1.43-1.54), 1.00 (0.95-1.05), 0.92 (0.83-1.01), respectively. Co-administration of vancomycin increased AKI rates (data not shown). Similarly, against the base rate of CDI (0.7%), these ratios were 1.21 (1.07-1.36), 1.89 (1.62-2.20), and 1.99 (1.55-2.56), respectively. Addition of vancomycin had minimal impact on CDI rates (data not shown).

CONCLUSIONS

Piperacillin/tazobactam increased AKI risk, which was exacerbated by concurrent vancomycin. Cefepime and meropenem increased CDI risk relative to piperacillin/tazobactam. Clinicians should consider the risks and benefits of AP-BL when selecting empiric regimens. Further well-designed studies evaluating the global risks of AP-BL and patient specific characteristics that can guide empiric selection are needed.

The higher the better? Defining the optimal beta-lactam target for critically ill patients to reach infection resolution and improve outcome

OBJECTIVES

Beta-lactam antibiotics are often subject to therapeutic drug monitoring, but breakpoints of target attainment are mostly based on expert opinions. Studies that show a correlation between target attainment and infection resolution are missing. This analysis investigated whether there is a difference in infection resolution based on two breakpoints of target attainment.

METHODS

An outcome group out of 1392 critically ill patients treated with meropenem or piperacillin-tazobactam was formed due to different selection criteria. Afterwards, three groups were created: group 1=free drug concentration (f) was < 100% of the time (T) above the minimal inhibitory concentration (MIC) (< 100% fT > MIC), group 2=100% fT > MIC < 4xMIC, and group 3=100% fT > 4xMIC. Parameters for infection control, renal and liver function, and estimated and observed in-hospital mortality were compared between those groups. Statistical analysis was performed with one-way analysis of variance, Tukey post hoc test, U test, and bivariate logistic regression.

RESULTS

The outcome group consisted of 55 patients (groups 1-3, 17, 24, and 14 patients, respectively). Patients allocated to group 2 or 3 had a significantly faster reduction of the C-reactive protein in contrast to patients allocated to group 1 (p = 0.033 and p = 0.026). Patients allocated to group 3 had a worse renal function, a higher Acute Physiology and Chronic Health Evaluation (APACHE II) score, were older, and had a significantly higher in-hospital mortality compared to group 1 (p = 0.017) and group 2 (p = 0.001). The higher mortality was significantly influenced by worse liver function, higher APACHE II, and higher Sequential Organ Failure Assessment (SOFA) score and norepinephrine therapy.

CONCLUSION

Achieving the target 100% fT > MIC leads to faster infection resolution in the critically ill. However, there was no benefit for patients who reached the highest target of 100% fT > 4xMIC, although the mortality rate was higher possibly due to confounding effects. In conclusion, we recommend the target 100% fT > MIC < 4xMIC for critically ill patients.

TRIAL REGISTRATION

NCT03985605.

Evaluation of the risk of acute kidney injury with the use of piperacillin/tazobactam among adult critically ill patients

PURPOSE

Piperacillin/tazobactam (PT), when combined with vancomycin, is associated with an increased risk of acute kidney injury (AKI). It is not known whether PT alone is associated with a higher incidence of AKI compared to other β-lactams among critically ill patients. The objective of this study was to compare the incidence of AKI associated with the use of PT to other β-lactams among adult critically ill patients METHODS: This retrospective study was conducted in the surgical and the medical intensive care units at two hospitals within Hamad Medical Corporation (HMC) in Qatar and included adult critically ill patients who received at least one dose of anti-pseudomonal β-lactams. The primary outcome was acute kidney injury, defined using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Multiple logistic regression with adjustment for pre-specified potential confounders was used for the primary outcome analysis.

RESULTS

A total of 669 patients were included in the analysis: 507 patients in the PT group and 162 patients in the control (meropenem/cefepime) group. AKI occurred in 136 (26.8%) members of the PT group and 38 (23.5%) members of the control group [odds ratio (OR) 1.2; 95% confidence interval (CI) 0.79-1.8]. The results were not significantly altered after adjusting for the pre-specified potential confounders (adjusted OR 1.38; 95% CI 0.88-2.15).

CONCLUSION

In this study, PT was not associated with a higher risk of AKI compared to cefepime or meropenem among adult critically ill patients.

Acute Kidney Injury Risk in Patients Treated with Vancomycin Combined with Meropenem or Cefepime

Background: No previous studies have determined the incidence of acute kidney injury (AKI) in trauma patients treated with vancomycin + meropenem (VM) versus vancomycin + cefepime (VC). The purpose of this study was to fill this gap. Methods: A series of 99 patients admitted to an American College of Surgeons-verified level 1 trauma center over a two-year period who received VC or VM for >48 hours were reviewed retrospectively. Exclusion criteria were existing renal dysfunction or on renal replacement therapy. The primary outcome was AKI as defined by a rise in serum creatinine (SCr) to 1.5 times baseline. Multi-variable analysis was performed to control for factors associated with AKI (age, obesity, gender, length of stay [LOS], nephrotoxic agent(s), and baseline SCr), with significance defined as p < 0.05. Results: The study population was 50 ± 19 years old, 76% male, with a median LOS of 21 [range 15-39] days, and baseline SCr of 0.9 ± 0.2 mg/dL. Antibiotics, diabetes mellitus, and Injury Severity Score were independent predictors of AKI (odds ratio [OR] 4.4; 95% confidence interval [CI] 1.4-12; OR 9.3; 95% CI 1-27; OR 1.2; 95% CI 1.023-1.985, respectively). The incidence of AKI was higher with VM than VC (10/26 [38%] versus 14/73 [19.1%]; p = 0.049). Conclusions: The renal toxicity of vancomycin is potentiated by meropenem relative to cefepime in trauma patients. We recommend caution when initiating vancomycin combination therapy, particularly with meropenem.