Development of Modernized Acinetobacter baumannii Susceptibility Test Interpretive Criteria for Recommended Antimicrobial Agents Using Pharmacometric Approaches.

Acinetobacter baumannii-Acinetobacter calcoaceticus complex (referred to herein as A. baumannii) treatment guidelines contain numerous older antimicrobial agents with susceptibility test interpretive criteria (STIC, also known as susceptibility breakpoints) set using only epidemiological data. We utilized a combination of in vitro surveillance data, preclinical murine thigh and lung infection models, population pharmacokinetics, simulation, and pharmacokinetic/pharmacodynamic (PK/PD) target attainment analyses to evaluate A. baumannii STIC for four commonly recommended antimicrobials from different classes (amikacin, ceftazidime, ciprofloxacin, and minocycline). Antimicrobial in vitro surveillance data were based on 1,647 clinical A. baumannii isolates obtained from 109 centers in the United States and Europe. Among these isolates, 5 were selected for evaluation in murine infection models based on fitness and MIC variability. PK and dose-ranging studies were conducted using neutropenic murine thigh and lung infection models The MIC ranges for the 5 isolates evaluated were as follows: amikacin, 2 to 32 µg/mL; ceftazidime, 4 to 16 µg/mL; ciprofloxacin, 0.12 to 2 µg/mL; minocycline, 0.25 to 4 µg/mL. All organisms grew ≥1.5 log10 CFU in both models in untreated controls. Plasma and epithelial lining fluid (ELF) pharmacokinetics for all drugs were determined in mice using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. For each isolate, 5 dose levels of each drug were tested individually in the thigh and lung infection model. The inoculum ranged from 7.9 to 8.4 and 6.8 to 7.7 log10 CFU/mL for the lung and thigh models, respectively. PK/PD targets associated with net bacterial stasis and 1- and 2-log10 CFU reductions from baseline were identified for each organism/infection model using Hill-type models. Population pharmacokinetic models for each agent were identified from the literature. Using demographic variables for simulated patients with hospital-acquired or ventilator-associated bacterial pneumonia or urinary tract infections (including acute pyelonephritis) who were administered maximal dosing regimens of each agent, estimates of protein binding, and ELF penetration ratios based on data from the literature, free-drug plasma and total-drug concentration-time profiles were generated, and PK/PD indices by MIC were calculated. Percent probabilities of attaining median and randomly assigned PK/PD targets associated with the above-described endpoints were determined. Recommended susceptible breakpoints for each agent were those representing the highest MIC at which the percent probabilities of achieving PK/PD targets associated with a 1-log10 CFU reduction from baseline approached or were ≥90%. The following susceptible breakpoints for A. baumannii were identified: amikacin, ≤8 µg/mL for pneumonia; ceftazidime, ≤32 and ≤8 µg/mL for pneumonia; ciprofloxacin, ≤1 µg/mL; and minocycline, ≤0.5/≤1 µg/mL which correspond to the standard and high minocycline dosing regimens of 200 mg per day and 200 mg every 12 h, respectively. Implementation of appropriate STIC will help clinicians optimally use the above-described agents and improve the likelihood of successful patient outcomes.

Pharmacokinetic-Pharmacodynamic Target Attainment Analyses as Support for Meropenem-Vaborbactam Dosing Regimens and Susceptibility Breakpoints.

Meropenem-vaborbactam is a fixed-dose beta-lactam/beta-lactamase inhibitor with potent in vitro and in vivo activity against Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales. Pharmacokinetic-pharmacodynamic (PK-PD) target attainment analyses were undertaken using population pharmacokinetic models, nonclinical PK-PD targets for efficacy, in vitro surveillance data, and simulation to provide support for 2 g meropenem-2 g vaborbactam every 8 h (q8h) administered as a 3-h intravenous (i.v.) infusion, and dosing regimens adjusted for patients with renal impairment. Simulated patients varying by renal function measure (estimated glomerular filtration rate [eGFR], mL/min/1.73 m2 and absolute eGFR, mL/min) and resembling the clinical trial population (complicated urinary tract infection, including acute pyelonephritis) were generated. The PK-PD targets for meropenem, the percentage of time on day 1 that free-drug plasma concentrations were above the MIC (%T>MIC), and vaborbactam, the ratio of free-drug plasma area under the concentration-time curve (AUC) on day 1 to the MIC (AUC:MIC ratio), were calculated. Percent probabilities of achieving meropenem free-drug plasma %T>MIC and vaborbactam free-drug plasma AUC:MIC ratio targets were assessed. MIC distributions for Enterobacterales, KPC-producing Enterobacterales, and Pseudomonas aeruginosa were considered as part of an algorithm to assess PK-PD target attainment. For assessments of free-drug plasma PK-PD targets associated with a 1-log10 CFU reduction from baseline, percent probabilities of PK-PD target attainment ranged from 81.3 to 100% at meropenem-vaborbactam MIC values of 4 or 8 µg/mL among simulated patients. The results of these PK-PD target attainment analyses provide support for a dosing regimen of 2 g meropenem-2 g vaborbactam q8h administered as a 3-h i.v. infusion, with dosing regimens adjusted for patients with renal impairment and a meropenem-vaborbactam susceptibility breakpoint of ≤8 µg/mL (tested with a fixed vaborbactam concentration of 8 µg/mL) for Enterobacterales and P. aeruginosa based on these dosing regimens.

The impact of mesenteric tension on pouch outcome and quality of life in patients undergoing restorative proctocolectomy.

AIM: The study aimed to establish a method for the measurement of mesenteric tension after ileal pouch-anal anastomosis (IPAA) and to evaluate the impact of tension on clinical outcome and quality of life. METHODS: All consecutive patients undergoing an open IPAA from July 2008 to October 2009 were prospectively enrolled. After the creation of the anastomosis, mesenteric tension was estimated by the surgeon in the operating room on a 10-point scale (1, least tension; 10, most tension). The association was analysed between mesenteric tension defined as low (1-2), medium (3-7) and high (8-10) and postoperative complications and quality of life (Cleveland Clinic Global Scale). RESULTS: A mesenteric tension score was obtained in 134 patients (71 men, 53.0%). Median age was 38.5 (29.3-47.0) years. Fifty-six patients (41.8%) had a low, 59 (44.0%) a medium and 19 (14.2%) a high degree of mesenteric tension. Patients with a high mesenteric tension had a shorter anal transitional zone, a longer distance from the upper border of the symphysis pubis to the apex of the small bowel loop designated for the ileoanal anastomosis, a thinner abdominal wall at the stoma site and a longer distance from the pouch to the ileostomy. The proportion of patients with high mesenteric tension was less after stapled anastomosis. On long-term follow-up, patients with high mesenteric tension were more likely to suffer from anastomotic stricture and pouch failure. Pouch function was not influenced by mesenteric tension. CONCLUSION: High mesenteric tension after IPAA is adversely associated with postoperative complications and pouch survival.

Pharmacokinetic-pharmacodynamic determinants of oseltamivir efficacy using data from phase 2 inoculation studies.

Given the limited understanding about pharmacokinetic-pharmacodynamic (PK-PD) determinants of oseltamivir efficacy, data from two phase 2 influenza virus inoculation studies were evaluated. Healthy volunteers in studies 1 and 2 were experimentally infected with influenza A/Texas (the concentration of neuraminidase inhibitor which reduced neuraminidase activity by 50% [IC(50)] = 0.18 nM) or B/Yamagata (IC(50) = 16.76 nM), respectively. In study 1, 80 subjects received 20, 100, or 200 mg of oral oseltamivir twice daily (BID), 200 mg oseltamivir once daily, or placebo for 5 days. In study 2, 60 subjects received 75 or 150 mg of oral oseltamivir BID or placebo for 5 days. Oseltamivir carboxylate (OC) (active metabolite) PK was evaluated using individual PK data and a population PK model to derive individual values for area under the concentration-time curve from 0 to 24 h (AUC(0-24)), minimum concentration of OC in plasma (C(min)), and maximum concentration of OC in plasma (C(max)). Exposure-response relationships were evaluated for continuous (area under composite symptom score curve [AUCSC], area under the viral titer curve, and peak viral titer) and time-to-event (alleviation of composite symptom scores and cessation of viral shedding) efficacy endpoints. Univariable analyses suggested the existence of intuitive and highly statistically significant relationships between OC AUC(0-24 )evaluated as a 3-group variable and AUCSC, time to alleviation of composite symptom scores, and time to cessation of viral shedding. The upper OC AUC(0-24) threshold (~14,000 ng · h/ml) was similar among these endpoints. Multivariable analyses failed to demonstrate the influence of study/strain on efficacy endpoints. These results provide the first demonstration of exposure-response relationships for efficacy for oseltamivir against influenza and suggest that OC exposures beyond those achieved with the approved oseltamivir dosing regimen will provide enhanced efficacy. The clinical applicability of these observations requires further investigation.

Morbidity and mortality of the Hartmann procedure for diverticular disease over 18 years in a single institution.

AIM: Hartmann's procedure for perforated diverticulitis is associated with substantial morbidity and mortality. This study analyses factors associated with morbidity/mortality and possible changes over time. METHOD: Patients treated by urgent Hartmann's procedure for perforated diverticulitis between 1992 and 2010 were studied, and information was collected on age, sex, perioperative details, 30-day morbidity and mortality recorded in an institutional review board approved database supplemented by chart review. Patients were divided into four groups based on the year of surgery. Univariate and multivariate logistic regression analysis was performed to identify risk factors associated with morbidity and mortality. RESULTS: In all, 199 patients (51% female, mean age 65 years, mean body mass index 28 kg/m(2)) were identified. The American Society of Anesthesiologists (ASA) score was 4 in 30% of patients and Hinchey Stage IV in 16%. The mean length of stay was 12.5 ± 10 days. Mortality was 15% and did not change significantly over time. Overall morbidity was 52% and significantly increased over time on univariate analysis (P = 0.007) but not on multivariate analysis (P = 0.11). Independent predictors of morbidity on multivariate analysis were Hinchey IV (P < 0.001) and hypoproteinaemia (P = 0.001). Independent predictors for mortality were ASA > 3 (P = 0.01), abnormal creatinine (P = 0.007), steroid use (P = 0.007), Hinchey IV (P = 0.032), low albumin (P < 0.001) and low body mass index (P = 0.001). CONCLUSION: Mortality after Hartmann's procedure for perforated diverticulitis has not decreased during the last 18 years. Morbidity has actually increased over time although this is related to increased disease severity and comorbidity. Future efforts should focus on the identification of patient subgroups benefiting from earlier elective surgery and alternative surgical approaches when perforated diverticulitis does occur.

Surgery of recurrent parastomal hernia: direct repair or relocation?

PURPOSE: Parastomal hernia is a common late complication after stoma creation. The management options are many; unfortunately, most literature suggests unsatisfactory results. There are few studies comparing the outcomes after repair of parastomal hernias especially in recurrent cases, and the results are controversial. The aim of this study was to compare outcomes after repair of recurrent parastomal hernias between direct repair (DR) and relocation (RL). METHOD: We performed a retrospective chart review of patients who underwent direct repair or RL for recurrent parastomal hernia during the period between 1990 and 2005. Perioperative data and re-recurrence rates were obtained and analysed with appropriate statistical methods. RESULTS: With mean follow-up time of 2 years, 50 operations were available for evaluation; 27 (54%) DR and 23 (46%) RL [five same-side RL (SSRL) and 18 opposite-side RL (OSRL)]. There were no deaths and there were similar complication rates between groups. Four of five (80%) SSRL had a re-recurrent parastomal hernia. Considering only DR with OSRL, although OSRL had longer operative time and hospital stay than DR, the re-recurrence rate was lower (38%vs 74%; P = 0.02). However, with Kaplan-Meier calculated and longer predicted follow-up time, re-recurrence rates were similar (Log rank P = 0.09). CONCLUSION: Recurrent parastomal hernia repair is associated with high re-recurrence rates.OSRL seems to have promising short-term outcomes; however, whether these results hold up long-term remains unclear. Therefore, larger cohorts of patients with longer follow-up or prospective randomized trials are needed.

Combined surgery in pelvic organ prolapse is safe and effective.

OBJECTIVE: In women, rectal prolapse is often accompanied by other signs of generalized pelvic floor weakness including uterine and bladder prolapse. The purpose of this study was to compare whether there are differences in outcomes of rectal prolapse surgery between women having combined pelvic organ prolapse (POP) surgery with a urologist or urogynecologist (CS) vs those having abdominal rectal prolapse surgery alone (RP). METHOD: Charts were reviewed to collect perioperative data on those having surgery from 1995 to 2001. Phone surveys were conducted to obtain Cleveland Clinic Foundation (CCF) Incontinence score, Knowles-Eccersley-Scott-Symptom (KESS) Constipation Score, Short Form 36 (SF-36) quality of life score and recurrence rate. Appropriate statistical analysis was performed. RESULTS: Ninety-four operations were performed (23 CS and 71 RP). Forty-six (49%) could be contacted by phone. Mean follow-up was similar in both groups (CS 4.1 vs RP 3.6 years; P = 0.796). There were no significant differences between both groups regarding age, American Society of Anesthesiology classification Score, complications, length of hospital stay, CCF Incontinence score, KESS Constipation Score, SF-36 Score and recurrence rate of rectal prolapse. The operative time (CS 226 vs RP 122 min; P < 0.001) and blood loss (CS 377 vs RP 183 ml; P < 0.001) were significantly increased in the CS group. CONCLUSION: Combined surgery for POP is safe and effective when considering outcomes of rectal prolapse surgery. Therefore surgeons should not hesitate to address all pelvic floor issues during the same operation by working in partnership with the anterior pelvic floor colleagues.

Cost-Effectiveness of daptomycin versus vancomycin and gentamicin for patients with methicillin-resistant Staphylococcus aureus bacteremia and/or endocarditis.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an increasingly common cause of bacteremia and endocarditis. The cost-effectiveness (CE) of daptomycin was compared with that of vancomycin-gentamicin in patients with MRSA bacteremia with or without endocarditis. METHODS: With use of data from an open-label, randomized study comparing daptomycin with vancomycin-gentamicin in the aforementioned patient population, 3 cost strata were considered: (1) study drug acquisition (daptomycin, $0.37/mg; vancomycin, $7/g; and gentamicin, $0.12/mg); (2) stratum 1 plus the cost of therapy for treatment failures and adverse events, therapeutic drug monitoring, and preparation and administration of all medications; and (3) stratum 2 plus hospital bed costs. Drug costs were based on mean wholesale price, with other costs based on those for a typical community hospital. Cost-effectiveness ratios were calculated as cost divided by proportion of successes. Sensitivity analyses were performed by varying the study drug cost. RESULTS: Forty-five (20 successes) and 44 (14 successes) patients received daptomycin and vancomycin-gentamicin, respectively. The respective median cost-effectiveness ratios for daptomycin and vancomycin-gentamicin for each cost stratum were as follows: $4082 (range, $1062-$13,893) and $560 (range, $66-$1649) for stratum 1 (P < .001); $4582 (range, $1109-$21,882) and $1635 (range, $163-$33,444) for stratum 2 (P = .026); $23,639 (range, $6225-$141,132) and $26,073 (range, $5349-$187,287) for stratum 3 (P = .82). Sensitivity analyses indicated that if the cost of vancomycin was $0, strata 3 cost-effectiveness ratios did not differ ($23,639 and $25,668, respectively; P = .85). Similar results between groups were seen among patients with bacteremia. CONCLUSIONS: When all costs of therapy were considered, the cost-effectiveness of daptomycin and vancomycin-gentamicin was similar, even if the cost of vancomycin was $0.

Typical and atypical chronic lymphocytic leukemia differ clinically and immunophenotypically.

We compared the features of 17 cases of atypical chronic lymphocytic leukemia (aCLL) with those of a clinical control group of 24 cases of CLL. Quantitative flow cytometric data, available for 12 cases, were compared with an immunophenotypic control group of 58 cases using a relative fluorescence indexfor CD5, CD23, CD79b, and surface immunoglobulin light chain (sIg). Compared with the clinical control group, patients with aCLL had a higher mean WBC count and a lower platelet count. Patients with aCLL had a significantly higher probability of disease progression. Compared with an immunophenotypic control group of 58 CLL cases, 12 cases of aCLL demonstrated significantly higher expression of CD23. There was no significant difference in expression of sIg, CD79b, or CD5 between the groups. CD38 expression was noted in only 1 (9%) of 11 tested cases; 2 (18%) of 11 cases had trisomy 12. aCLL can be distinguished from typical CLL morphologically, clinically, and immunophenotypically. Atypical morphologic features in CLL seem to be a marker of aggressive clinical behavior.

Impact of apolipoprotein(a) isoform size heterogeneity on the lysine binding function of lipoprotein(a) in early onset coronary artery disease.

Elevated plasma Lp(a) is an independent risk factor for cardiovascular disease. Unique to Lp(a) is the apoprotein, apo(a) which can vary from 250 to 800 kDa in molecular weight. Small isoforms are also associated with the risk of cardiovascular disease. The purpose of this study was to examine the association of Lp(a) concentration, apo(a) size, and Lp(a) lysine-binding site(s) (LBS) function in patients with early onset heart disease, and age-matched controls. Mean values of Lp(a) were significantly higher in the patients than for the age-matched group. The smallest molecular weight isoform for each subject had significantly fewer kringles for the patients than the age-matched controls. There was a significant correlation between LBS activity and kringle number in the single-banded phenotypes of the patients, but not the controls. LBS activity was significantly higher in patients with small isoforms (< or =18 kringles) compared to controls. The odds ratio for coronary artery disease for high LBS activity and high Lp(a) concentration was 4.4 (p = 0.002) and for high LBS activity and small isoforms was 10.1 (p = 0.002). In the patients, Lp(a) concentration was higher, apo(a) size was smaller, and LBS activity higher in the small isoforms compared to the controls. This study suggests an association of high LBS activity in small isoforms of Lp(a) with disease in humans.

Feasibility of a nurse-run asthma education program for urban African-Americans: a pilot study.

The objective of the study was to assess the feasibility of implementing and evaluating a culturally appropriate in-patient asthma education program specifically targeted for African-Americans. A consecutive sample of 28 African-American patients ages 18-50 who were hospitalized for asthma were randomized to an intervention group, which received three one-on-one sessions on chronic asthma management, or a control group, which received the usual care. Data on symptom frequency, self-management behaviors, quality of life, depression, and health care resource use were collected at baseline and at 3 and 6 months. Although the time required to recruit our sample took longer than anticipated, 28 subjects agreed to be in the study (70% acceptance rate) and complete the baseline interview. We observed no statistically significant differences from baseline or changing trends in frequency of asthma symptoms, self-management behaviors, and health care resource use between the intervention and control groups at 3 and 6 months. However patients in the intervention group demonstrated a greater average increase in asthma-related quality of life and a greater average decrease in depression than the control group. Feasibility issues included shortened length of stay, which necessitated conducting all three self-management sessions together; multiple interruptions during the sessions, and retention issues at 3- and 6-month follow-ups. The lessons learned from this pilot study are invaluable in that they will enable us to make changes in our existing protocol to ensure the success of a larger clinical trial.

Usefulness of CD79b expression in the diagnosis of B-cell chronic lymphoproliferative disorders.

We evaluated anti-CD79b for its usefulness in the diagnosis of B-cell chronic lymphoproliferative disorders (BCLPDs), particularly chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). We analyzed 100 BCLPDs for CD5, CD19, CD20, CD23, CD79b, and surface immunoglobulin light chain (sIg) expression by 4-color flow cytometry. CD20, CD79b, and sIg expression were quantified. Correlational analysis and univariable and multivariable logistic regression models were used to determine the best combination of antigens for the immunophenotypic classification of CLL vs other BCLPDs. Positive and statistically significant Spearman pairwise correlations between CD20, CD79b, and sIg fluorescence intensity were demonstrated. In the simplest models in which a single variable was considered, cutoff points were chosen that gave misclassification rates for CLL of 16% for CD79b, 19% for sIg, and 18% for CD20. Low-intensity CD79b, CD20, and sIg are associated highly with CLL. A panel containing CD5, CD19, CD23, and sIg allowed correct classification of most cases. Addition of CD20 or CD79b improved diagnostic accuracy; CD79b was slightly better than CD20. CD79b seems to be a useful addition to a standard flow cytometry panel for the evaluation of BCLPDs.

Use of tissue-type plasminogen activator for acute ischemic stroke: the Cleveland area experience.

CONTEXT: Little is known regarding outcomes after intravenous tissue-type plasminogen activator (IV tPA) therapy for acute ischemic stroke outside a trial setting. OBJECTIVE: To assess the rate of IV tPA use, the incidence of symptomatic intracerebral hemorrhage (ICH), and in-hospital patient outcomes throughout a large urban community. DESIGN: Historical prospective cohort study conducted from July 1997 through June 1998. SETTING: Twenty-nine hospitals in the Cleveland, Ohio, metropolitan area. PATIENTS: A total of 3948 patients admitted to a study hospital with a primary diagnosis of ischemic stroke (International Classification of Diseases, Ninth Revision, Clinical Modification code 434 or 436). MAIN OUTCOME MEASURES: Rate of IV tPA use and occurrence of symptomatic ICH among patients treated with tPA; proportion of patients receiving tPA whose treatment deviated from national guidelines; in-hospital mortality among patients receiving tPA compared with that among ischemic stroke patients not receiving tPA and with mortality predicted by a model. RESULTS: Seventy patients (1.8%) admitted with ischemic stroke received IV tPA. Of those, 11 patients (15.7%; 95% confidence interval [CI], 8.1%-26.4%) had a symptomatic ICH (of which 6 were fatal) and 50% (95% CI, 37.8%-62.2%) had deviations from national treatment guidelines. In-hospital mortality was significantly higher among patients treated with tPA (15.7%) compared with patients not receiving tPA (5.1%, P<.001) and compared with the model's prediction (7.9%; P<.006). CONCLUSIONS: A small proportion of patients admitted with acute ischemic stroke in Cleveland received tPA; they experienced a high rate of ICH. Cleveland community experience with tPA for acute ischemic stroke may differ from that reported in clinical trials.

Increased glutathione and glutathione peroxidase in lungs of individuals with chronic beryllium disease.

Reactive oxygen species (ROS) are mediators of chronic tissue damage and fibrosis. Endogenous antioxidants may increase in response to oxidants and reduce tissue injury. We investigated the antioxidant response of the lungs to the chronic release of ROS, as occurs in the immune-specific granulomatous inflammation of chronic beryllium disease (CBD), and compared it with that in healthy controls and individuals exposed to cigarette smoke. The antioxidants superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione (GSH) were quantitated in lung epithelial lining fluid (ELF) and serum from control subjects (n = 10), cigarette smokers (n = 8), and individuals with CBD (n = 9). GPx activity and extracellular GPx (eGPx) protein were increased in the ELF of subjects with CBD in comparison with that of control subjects and smokers (eGPx in ELF: controls, 1.3 +/- 0.2 microgram/ml, smokers, 1.9 +/- 0.3 microgram/ml, CBD, 3.8 +/- 0.8 microgram/ml; p = 0.002; GPx U/ml ELF, controls 1.4 +/- 0.3, smokers 1.8 +/- 0.4, CBD, 4.5 +/- 1, p = 0.02). Smokers' ELF had higher levels of GSH than that of controls, but CBD patients' ELF contained much more GSH than that of either controls or smokers (p < 0.001). Increases in GSH were correlated with eGPx, indicating similar inducing mechanisms for these antioxidants. Thus, coordinate augmentation of the glutathione antioxidant system occurs in granulomatous lung inflammation.