Case Report: Extended Duration Andexanet Alfa Infusion in a Surgical Trauma Patient.

Background: Andexanet alfa (andexanet) is the only FDA-approved medication for reversal of apixaban and rivaroxaban anticoagulation for life-threatening or uncontrolled bleeding. Infusion modifications may be required in surgical patients undergoing prolonged operative intervention but have not previously been described. Case Report: A 78-year-old woman on rivaroxaban for atrial fibrillation was admitted to the trauma service for a mechanical fall, sustaining a T4 burst fracture with severe canal stenosis and spinal cord edema resulting in loss of strength and sensation in her legs. Clinically relevant rivaroxaban activity was verified with an elevated low molecular weight heparin anti-factor Xa assay, and laboratory confirmed coagulopathy was demonstrated by a prolonged prothrombin time, thromboelastography (TEG) R-time, and activated clotting time (ACT). The patient required urgent surgical intervention for spinal fixation. Given the expected prolonged duration of the procedure, standard dose andexanet was initiated with a prolonged infusion at half the standard rate during the operation. The procedure was successful and intraoperative TEGs demonstrated normalization of R-time and ACT throughout the procedure. The patient did not experience any complications postoperatively and successfully discharged to inpatient rehabilitation. Conclusion: Modifications to the andexanet infusion may be required in surgical patients requiring rivaroxaban reversal for a prolonged procedure. Further data are needed to determine the optimal approach to infusion modification.

Clinical Experience, Characteristics, and Performance of an Acetaminophen Absorption Test in Critically Ill Patients.

BACKGROUND: Altered drug and nutrient absorption presents a unique challenge in critically ill patients. Performing an acetaminophen absorption test (AAT) has been used as a marker for gastric motility and upper small bowel absorption; thus, it may provide objective data regarding enteral absorptive ability in critically ill patients. STUDY QUESTION: What is the clinical experience with AAT when used as a surrogate marker for enteral absorption in critically ill patients? STUDY DESIGN: This single-center, retrospective, cohort study evaluated serum acetaminophen concentrations within 180 minutes following 1-time enteral administration of an AAT. Patients admitted to the surgical and medical intensive care units and medical intensive care units over a 7-year period were evaluated. Groups were defined as positive (acetaminophen concentration of ≥10 mg/L) or negative (acetaminophen concentration of <10 mg/L) AAT. MEASURES AND OUTCOMES: The outcomes were to describe the clinical experience, characteristics, and performance of AAT. RESULTS: Forty-eight patients were included. Patients were 58.5 ± 14 years of age, mostly male (58.3%), and admitted to the surgical intensive care unit (66.7%). Median hospital length of stay was 47.5 (27-78.8) days. Thirty-four patients (70.8%) had a positive AAT [median concentration, 14 (12-18) mg/L]. Median time to first detectable concentration was 37 (33-64) minutes. AAT characteristics were similar between the groups including total dose, weight-based dose, time to first and second assays, drug formulation, and site of administration between groups. There were no independent risk factors identified on regression analysis for negative AAT. CONCLUSIONS: An acetaminophen dose of 15 mg/kg with 2 coordinated serum concentrations approximately 30 and 60 minutes after administration is a reasonable construct for AAT. Future research is needed to assess AAT utility, safety, and clinical outcomes for predicting patient ability to absorb enteral feeds and medications.

Assessment of Detectable Serum Tobramycin Concentrations in Patients Receiving Inhaled Tobramycin for Ventilator-Associated Pneumonia.

BACKGROUND: Inhaled tobramycin can be used for empiric or definitive therapy of ventilator-associated pneumonia (VAP) in mechanically ventilated patients. This is believed to minimize systemic exposure and potential adverse drug toxicities including acute kidney injury (AKI). However, detectable serum tobramycin concentrations have been reported after inhaled tobramycin therapy with AKI. METHODS: This retrospective, observational study evaluated mechanically ventilated adult subjects admitted to ICUs at a large, urban academic medical center that received empiric inhaled tobramycin for VAP. Subjects were separated into detectable (ie, ≥ 0.6 mg/L) or undetectable serum tobramycin concentration groups, and characteristics were compared. Independent predictors for detectable serum tobramycin concentration and new onset AKI during or within 48 h of therapy discontinuation were assessed. RESULTS: Fifty-nine inhaled tobramycin courses in 53 subjects were included in the analysis, of which 39 (66.1%) courses administered to 35 (66.0%) subjects had detectable serum tobramycin concentrations. Subjects with detectable serum tobramycin concentrations were older (57.1 y ± 11.4 vs 45.9 ±15.0, P = .004), had higher PEEP (9.2 cm H2O [7.0-11.0] vs 8.0 [5.6-8.9], P = .049), chronic kidney disease stage ≥ 2 (10 [29.4%] vs 0 [0%], P = .009), and higher serum creatinine before inhaled tobramycin therapy (1.26 mg/dL [0.84-2.18] vs 0.76 [0.47-1.28], P = .004). Age (odds ratio 1.09 [95% CI 1.02-1.16], P = .009) and PEEP (odds ratio 1.47 [95% CI 1.08-2.0], P =.01) were independent predictors for detectable serum tobramycin concentration. Thirty-seven subjects had no previous renal disease or injury, of which 9 (24.3%) developed an AKI. Sequential Organ Failure Assessment score (odds ratio 1.72 [95% CI 1.07-2.76], P = .03) was the only independent predictor for AKI. CONCLUSIONS: Detectable serum tobramycin concentrations were frequently observed in critically ill, mechanically ventilated subjects receiving empiric inhaled tobramycin for VAP. Subject age and PEEP were independent predictors for detectable serum tobramycin concentration. Serum monitoring and empiric dose reductions should be considered in older patients and those requiring higher PEEP.

Comparison of Ceftriaxone and Antipseudomonal ß-Lactam Antibiotics Utilized for Potential AmpC ß-Lactamase-Producing Organisms.

Background: Induction of antibiotic resistance is associated with increased morbidity and mortality in AmpC ß-lactamase producing Enterobacteriaceae. The use of ceftriaxone is controversial for treatment of these organisms due to concerns for inducible resistance. This study was designed to compare treatment failure rates between ceftriaxone and antipseudomonal ß-lactam antibiotics when used as definitive therapy for organisms most commonly associated with chromosomal AmpC ß-lactamase production. Methods: A retrospective, single-center cohort study was performed enrolling patients hospitalized with monomicrobial Enterobacter, Citrobacter, or Serratia spp. infections. The primary objective compared proportion of treatment failure between groups. All patients received either ceftriaxone or an antipseudomonal ß-lactam alone within 24 hours of culture finalization, and with a duration of at least 72 hours for definitive treatment. Treatment failure was defined as either clinical failure (abnormal white blood cell count or temperature on day 7 or 14 post-antibiotics) or microbiologic failure (regrowth of the same organism at same site within 14 or 21 days). Results: Of 192 total patients, treatment failure was observed in 24/71 patients (34%) receiving ceftriaxone and in 42/121 patients (35%) receiving antipseudomonal ß-lactam (P = .98). No difference was observed between clinical or microbiologic failure rates between groups. The ceftriaxone group had significantly more patients undergoing treatment for urinary tract infections (51% vs 17%, P < .001), but treatment failure rates remained similar between groups when comparing infections of all other sources. Conclusion: Ceftriaxone has comparable treatment failure rates to antipseudomonal ß-lactams for susceptible Enterobacteriaceae infections and may be considered as a therapeutic option. Further, prospective research is needed to validate optimal dosing and application in all sites of infection.

Cefepime Population Pharmacokinetics and Target Attainment in Critically Ill Patients on Continuous Renal Replacement Therapy.

Sepsis causes half of acute kidney injuries in the intensive care unit (ICU). ICU patients may need continuous renal replacement therapy (CRRT), which will affect their antimicrobial exposure. We aimed to build a cefepime population pharmacokinetic (PK) model in CRRT ICU patients and perform simulations to assess target attainment. Patients who were ≥18 years old, were admitted to the ICU, and received cefepime 2 g every 8 h as a 4-h infusion while on CRRT were enrolled prospectively. Samples were collected from the predialyzer ports, postdialyzer ports, and effluent fluid at 1, 2, 3, 4, and 8 h after the first dose and at steady state. Age, sex, weight, urine output, and CRRT parameters were recorded. Pmetrics was used for population PK and simulations. The target exposure was 100% of the dosing interval during which the free beta-lactam concentration is above the MIC (fT>MIC). Ten patients were included; their mean age was 53 years, and mean weight was 119 kg. Seventy percent were males. Cefepime was described by a five-compartment model. The downtime was applied to the CRRT flow rates, which were used to describe the rates of transfer between the compartments. At MICs of ≤8 mg/liter, intermittent infusion of 2 g cefepime every 8 h achieved good target attainment both early in therapy and at steady state. Only extended- and continuous-infusion regimens achieved good target attainment at MICs of 16 mg/liter. In conclusion, 2 g cefepime infused over 30 min followed by extended infusion of 2 g every 8 h achieved good target attainment at MICs of ≤16 mg/liter with different CRRT flow rates and may be considered in resistant bacterial infections.

Admission thrombelastography does not guide dose adjustment of enoxaparin in trauma patients.

BACKGROUND: Enoxaparin is used as chemoprophylaxis to reduce incidence of venous thromboembolism and its complications following trauma. Serum anti-Xa monitoring is used to assess efficacy but requires several doses to be administered. Thrombelastography assesses hypercoagulability and may have utility identifying high-risk patients for venous thromboembolism. The objective was to evaluate whether thrombelastography parameters could identify trauma patients requiring enoxaparin dose adjustment earlier than serum anti-Xa concentrations. METHODS: A single-center, retrospective medical record review evaluated patients admitted to a regional level I trauma center that received an admission thrombelastography and a dose of enoxaparin with a serum trough anti-Xa concentration drawn. Patients were divided into standard-dose or dose-adjusted enoxaparin. Venous thromboembolism incidence between groups and risk factors for enoxaparin dose adjustment and venous thromboembolism development were evaluated. RESULTS: A total of 204 patients were included. Differences observed between groups included age (standard-dose enoxaparin, 48.5 [29.3-72] vs dose-adjusted enoxaparin, 38.5 [25-55.7] years; P = .005), admission creatinine clearance (standard-dose enoxaparin, 92.9 [67.4-113.4] vs dose-adjusted enoxaparin, 102.1 [83.8-129.2] mL/min; P = .017), and time to venous thromboembolism prophylaxis initiation (standard-dose enoxaparin, 23.8 [11.2-36.4] vs dose-adjusted enoxaparin, 34.5 [18.3-52.7] hours; P = .004). No differences in thrombelastography parameters or venous thromboembolism incidence were observed. No independent risk factors for enoxaparin dose adjustment were identified; however, risk assessment profile score > 10 was an independent risk factor for venous thromboembolism development. CONCLUSION: No relationship between admission thrombelastography and need for enoxaparin dose adjustment in trauma patients was observed. As thrombelastography continues growing in clinical use, it is prudent to investigate other potential applications. Currently, thrombelastography should not be used to guide enoxaparin dosing.

Retrospective Evaluation of Venous Thromboembolism Prophylaxis in Elderly, High-Risk Trauma Patients.

BACKGROUND: Venous thromboembolism (VTE) risk increases with age. Scarce data exist for patients age ≥65 y. This study evaluated VTE incidence in elderly, high-risk trauma patients receiving unfractionated heparin (UFH) or enoxaparin chemoprophylaxis. MATERIALS AND METHODS: This retrospective, single-center, cohort study included trauma patients age ≥ 65 y with risk assessment profile (RAP) ≥ 5 who received UFH or enoxaparin chemoprophylaxis. The primary outcome was VTE incidence requiring therapeutic anticoagulation. An age-modified RAP (RAP-AM) was calculated as RAP without age distribution points. Logistic regression analyses were performed to identify independent predictors for VTE development and chemoprophylactic agent selection. Bleeding incidence compared packed red blood cells utilized. RESULTS: A total of 1090 patients were included (UFH, n = 655; enoxaparin, n = 435). VTE occurred in 39 (3.6%) patients with no difference between groups in proximal deep vein thrombosis (2.1% versus 3.0%, P = 0.52) or pulmonary embolism (1.2% versus 1.4%, P = 0.96). Weight ≥125 kg (OR 4.12, 95% CI 1.06-16.11) and RAP-AM ≥ 5 (OR 6.52, 95% CI 2.65-16.03) were independently associated with VTE development. Increasing age (OR 1.04, 95% CI 1.03-1.06), initiation ≤ 24 h (OR 2.17, 95% CI 1.66-2.84) and creatinine clearance ≤ 30 mL/min (OR 1.61, 95% CI 1.17-2.21) were independent predictors of receiving UFH whereas increasing ISS (OR 0.97, 95% CI 0.95-0.99) was associated with receiving enoxaparin. CONCLUSIONS: VTE incidence may be similar for high-risk, elderly trauma patients receiving UFH and enoxaparin chemoprophylaxis. Further research is necessary to determine noninferiority of UFH to enoxaparin in this patient population.

Pharmacokinetics and Pharmacodynamics of Extended-Infusion Cefepime in Critically Ill Patients Receiving Continuous Renal Replacement Therapy: A Prospective, Open-Label Study.

STUDY OBJECTIVE: To evaluate extended-infusion (EI) cefepime pharmacokinetics (PK) and pharmacodynamic target attainment in critically ill patients receiving continuous venovenous hemofiltration (CVVH) or continuous venovenous hemodialysis (CVVHD). DESIGN: Prospective, open-label, PK study. SETTING: Intensive care units at a large, academic, tertiary-care medical center. PATIENTS: Ten critically ill adults who were receiving cefepime 2 g intravenously every 8 hours as a 4-hour infusion while receiving CVVH (eight patients) or CVVHD (two patients). INTERVENTION: Two sets of five serum cefepime concentrations were collected for each patient to assess pharmacokinetics before and during presumed steady state. Concurrent serum and CRRT effluent samples were collected at hours 1, 2, 3, 4, and 8 after the first cefepime dose and after either the fourth, fifth, or sixth (steady-state) cefepime doses. MEASUREMENTS AND MAIN RESULTS: Reversed-phase high-performance liquid chromatography was used to determine free cefepime concentrations. PK analyses included CRRT clearance, half-life, and sieving coefficient or saturation coefficient. Cefepime peak (4 hrs) concentrations, trough (8 hrs) concentrations (Cmin ), and minimum inhibitory concentration breakpoint of 8 µg/ml for the pathogen (MIC8 ) were used to evaluate attainment of pharmacodynamic targets: 100% of the dosing interval that free drug remains above MIC8 (100% fT > MIC8 ), 100% fT > 4 × MIC8 (optimal), percentage of time fT > 4 × MIC8 (%fT > 4 × MIC8 ) at steady state, and ratio of Cmin to MIC8 (fCmin /MIC8 ). Total CRRT effluent flow rate was a mean ± SD of 30.1 ± 5.4 ml/kg/hr, CRRT clearance was 39.6 ± 9.9 ml/min, and half-life was 5.3 ± 1.7 hours. Sieving coefficient or saturation coefficient were 0.83 ± 0.13 and 0.69 ± 0.22, respectively. First and steady-state dose Cmin were 23.4 ± 10.1 µg/ml and 45.2 ± 14.6 µg/ml, respectively. All patients achieved 100% fT > MIC8 on first and steady-state doses. First and steady-state dose 100% fT > 4 × MIC8 were achieved in 22% (2/9 patients) and 87.5% (7/8 patients) of patients, respectively. The mean %fT > 4 × MIC8 at steady state was 97.5%. The fCmin /MIC8 was 2.92 ± 1.26 for the first dose and 5.65 ± 1.83 at steady state. CONCLUSION: Extended-infusion cefepime dosing in critically ill patients receiving CRRT successfully attained 100% fT > MIC8 in all patients and an appropriate fCmin /MIC8 for both first and steady-state doses. All but one patient achieved 100% fT > 4 × MIC8 at steady state. No significant differences were observed in PK properties between first and steady-state doses among or between patients. It may be reasonable to initiate an empiric or definitive regimen of EI cefepime in critically ill patients receiving concurrent CRRT who are at risk for resistant organisms. Further research is needed to identify the optimal dosing regimen of EI cefepime in this patient population.

Recognition, Assessment, and Pharmacotherapeutic Treatment of Alcohol Withdrawal Syndrome in the Intensive Care Unit.

Alcohol withdrawal syndrome (AWS) is a complex neurologic disorder that develops after an acute reduction in or cessation of chronic alcohol consumption that alters neurotransmitter conduction. The incidence of AWS in the intensive care unit varies, but has been associated with poor outcomes. This is primarily driven by downregulation of gamma-aminobutyric acid (GABA) leading to autonomic excitability and psychomotor agitation. No clinical assessment tools have been validated to assess for AWS in the intensive care unit, particularly for patients requiring mechanical ventilation. The Clinical Institute Withdrawal Assessment for Alcohol Scale, Revised, may be considered to gauge the extent of withdrawal, but is not particular with acute presentations in this population. Symptom-triggered use of GABA agonist such as benzodiazepines remains the mainstay of pharmacotherapeutic intervention. Nonbenzodiazepine GABA agonists such as barbiturates and propofol as well as non-GABA adjunctive agents such as dexmedetomidine, ketamine, and antipsychotic agents may help reduce the need for symptom-triggered benzodiazepine dosing, but lack robust data. Agent selection should be based on patient-specific factors such as renal and hepatic metabolism, duration of action, and clearance. Institution-specific protocols directing GABA-acting medications and adjunctive medications for excitatory, adrenergic, and delirium assessments could be considered to improve patient outcomes and caregiver satisfaction.

Evaluation of Thrombocytopenia in Critically Ill Patients Receiving Continuous Renal Replacement Therapy.

BACKGROUND: Continuous renal replacement therapy (CRRT) may be associated with thrombocytopenia in critically ill patients. A confounding factor is concomitant use of unfractionated heparin (UFH) and suspicion for heparin-induced thrombocytopenia (HIT). OBJECTIVE: To determine the impact of CRRT on platelet count and development of thrombocytopenia. METHODS: Retrospective analyses evaluated the intrapatient change in platelet count following CRRT initiation. Critically ill adult patients who received CRRT for at least 48 hours were included. The primary outcome was intrapatient change in platelet count from CRRT initiation through the first 5 days of therapy. Secondary outcomes included thrombocytopenia incidence, identification of concomitant factors associated with thrombocytopenia, and frequency of HIT. RESULTS: 80 patients were included. Median platelet count at CRRT initiation (D0) was 128000/µL (81500-212500/µL), which was higher than those on subsequent post-CRRT days (D1: 104500/µL [63000-166750/µL]; D2: 88500/µL [53500-136750/µL]; D3: 91000/µL [49000-138000/µL]; D4: 93000/µL [46000-134000/µL]; and D5: 76000/µL [45500-151000/µL]; P < 0.05 for all). Twenty-five (35%) patients had thrombocytopenia on CRRT D0 compared with D2 (56.3%), D3 (58.7%), and D5 (59.1%); P < 0.05 for all. Controlling for potential confounders, Sequential Organ Failure Assessment score at the time of CRRT initiation was the only independent factor associated with thrombocytopenia. One (1.3%) patient had confirmed HIT. Conclusion and Relevance: This study is the first to demonstrate serial decreases in platelet count across multiple days after CRRT initiation. These data may provide additional insight to thrombocytopenia development in critically ill patients receiving heparin while on CRRT that is not associated with HIT.

Impact of Norepinephrine Weight-Based Dosing Compared With Non-Weight-Based Dosing in Achieving Time to Goal Mean Arterial Pressure in Obese Patients With Septic Shock.

Obesity presents a growing challenge in critically ill patients because of variable medication pharmacokinetics and pharmacodynamics. Vasopressors used in the treatment of septic shock, including norepinephrine, are dosed using weight-based (WB) or non-weight-based (NWB) strategies. Retrospective research has evaluated the effect of total body weight and body mass index on vasopressor requirements, consequently finding that obese patients require less total vasopressor per kilogram to obtain clinical end points such as mean arterial pressure. Although this effect is not completely understood, this may suggest that a NWB dosing strategy is preferred over a WB strategy in obese patients to minimize potential for error.

Long acting muscarinic antagonists for the treatment of chronic obstructive pulmonary disease: a review of current and developing drugs.

INTRODUCTION: Long acting muscarinic receptor antagonists (LAMA) reverse airflow obstruction by antagonizing para-sympathetic bronchoconstricting effects within the airways. For years, tiotropium, has been the cornerstone LAMA for chronic obstructive pulmonary disease (COPD) management. Recently, new agents, aclidinium bromide, glycopyrronium bromide, and umeclidinium bromide, have been developed and introduced into clinical practice. Areas covered: This article reviews the clinical efficacy and adverse effects of currently available LAMAs in COPD treatment as well as developing LAMAs in early clinical trials and preclinical studies (V0162, TD-4208, CHF 5407, AZD9164, AZD8683, bencycloquidium). In addition, a new class of molecule that combines muscarinic antagonist and ß2-adrenergic properties (MABA) is described and current developmental progress discussed (GSK-961081, THRX-200495). Expert opinion: Future key areas for developing drugs for the management of COPD include prolonged duration of action, optimal delivery systems, synergistic combinations with other drugs, maximization of benefits and minimization of adverse effects. The development of new LAMA and MABA molecules provides exciting progress towards simpler and more effective COPD management.

Phosphodiesterase 4 inhibitors for the treatment of chronic obstructive pulmonary disease: a review of current and developing drugs.

INTRODUCTION: Phosphodiesterase (PDE) inhibitors modulate lung inflammation and cause bronchodilation by increasing intracellular cyclic adenosine 3', 5'-monophosphate in airway smooth muscle and inflammatory cells. Roflumilast is the only approved PDE-4 inhibitor (PDE4I) for use in chronic obstructive pulmonary disease (COPD). Its beneficial clinical effects occur preferentially in patients with chronic bronchitis and frequent COPD exacerbations. Use of roflumilast as adjunctive or alternate therapy to other COPD medications reduces exacerbations and modestly improves lung function. AREAS COVERED: This article reviews the current role of PDE4I in COPD treatment emphasizing roflumilast's clinical efficacy and adverse effects. This article also reviews developing PDE4Is in early clinical trials and in preclinical studies. EXPERT OPINION: After decades of research in drug development, PDE4Is are a welcomed addition to the COPD therapeutic armamentarium. In its current clinical role, the salubrious clinical effects of PDE4I in reducing exacerbations and stabilizing the frequent exacerbator phenotype have to be cautiously balanced with numerous adverse effects. Developing drugs may provide similar or better clinical benefits while minimizing adverse effects by changing the mode of drug delivery to inhaled formulations, combining dual PDE isoenzyme inhibitors (PDE1/4I and PDE3/4I) and by forming hybrid molecules with other bronchodilators (muscarinic receptor antagonist/PDE4I and ß2-agonist/PDE4I).

Effect of a dalteparin prophylaxis protocol using anti-factor Xa concentrations on venous thromboembolism in high-risk trauma patients.

BACKGROUND: Low anti-factor Xa (anti-Xa) concentrations with twice-daily enoxaparin are associated with venous thromboembolism (VTE) in high-risk trauma patients. Concerns have been raised with once-daily dalteparin regarding effectiveness and achievable anti-Xa concentrations. The purpose of this before-and-after study was to evaluate the effectiveness of a VTE prophylaxis protocol using anti-Xa concentrations and associated dalteparin dose adjustment in high-risk trauma patients. METHODS: Adult trauma patients receiving VTE chemoprophylaxis and hospitalized for at least 3 days were prospectively followed during two 6-month epochs before (PRE) and after (POST) implementation of anti-Xa monitoring. In both groups, high-risk patients received dalteparin 5,000 U subcutaneously once daily; low-risk patients received subcutaneous unfractionated heparin. High-risk POST patients with anti-Xa less than 0.1 IU/mL 12 hours after initial dalteparin dose received dalteparin every 12 hours. All patients underwent routine VTE ultrasound surveillance of the lower extremities. The primary outcome was incidence of VTE. RESULTS: A total of 785 patients (PRE, n = 428; POST, n = 357) were included. Demographics, injury patterns, Injury Severity Score (ISS), red blood cell transfusions, intensive care unit and hospital stays, and mortality did not differ between groups. Overall, POST patients had lower VTE (7.0% vs. 13%, p = 0.009) including acute VTE (6.4% vs. 12%, p = 0.01) and proximal deep vein thromboembolism (2.2% vs. 5.7%, p = 0.019). Between high-risk patients, VTE occurred in 53 (16.3%) PRE compared with 24 (9.0%) POST patients (p = 0.01); there was no difference in VTE between low-risk patients (PRE, 2.0% vs. POST, 1.1%; p = 0.86). Among 190 high-risk POST patients with anti-Xa, 97 (51%) were less than 0.1 IU/mL. Patients with low anti-Xa had higher rates of VTE (14.0% vs. 5.4%, p = 0.05) and deep vein thromboembolism (14.4% vs. 3.2%, p = 0.01). Younger age (odds ratio, 0.97; 95% confidence interval, 0.95-0.99) and greater weight (odds ratio, 1.02; 95% confidence interval, 1.00-1.03) predicted low anti-Xa on multivariate regression. CONCLUSION: A VTE prophylaxis protocol using anti-Xa-based dalteparin dosage adjustment in high-risk trauma patients was associated with decreased VTE. Once-daily dalteparin 12-hour anti-Xa concentrations are suboptimal in a majority of patients and associated with VTE. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Effects of critical illness and organ failure on therapeutic argatroban dosage requirements in patients with suspected or confirmed heparin-induced thrombocytopenia.

BACKGROUND: Critically ill patients often require therapeutic argatroban dosages lower than those recommended in package labeling. The magnitude of dosage alteration in relation to severity of organ failure is unknown. OBJECTIVE: To compare therapeutic argatroban dosages between critically ill and noncritically ill patients with confirmed or suspected heparin-induced thrombocytopenia and investigate the relationship between total Sequential Organ Failure Assessment (SOFA) score and therapeutic argatroban dosage. METHODS: This retrospective cohort study was conducted at an urban academic medical center. Adults without Child-Pugh class C hepatic dysfunction who received argatroban for more than 24 hours over a 3-year period were included. Therapeutic argatroban dosage was that resulting in 2 consecutive activated partial thromboplastin time (aPTT) values 1.5-3 times the patient-specific baseline obtained at least 4 hours apart. Initial argatroban dosages were at the discretion of the managing service. RESULTS: Fifty-three patients (critically ill, n = 34; noncritically ill, n = 19) were included. Critically ill patients had higher median [interquartile range] Acute Physiology and Chronic Health Evaluation (APACHE II) (17 [12-21] vs 10 [3.25-17.75]; p = 0.007) and SOFA (11 [7-13] vs 2 [0-2.75]; p < 0.001) scores. Critically ill patients required lower mean +/- SD therapeutic argatroban dosage (0.6 +/- 0.5 vs 1.4 +/- 0.9 microg/kg/min; p < 0.001). There was no significant difference in time to therapeutic aPTT or proportion of aPTTs within therapeutic range. Argatroban dosage was inversely related to SOFA score tertiles (<6: 1.34 +/- 0.82 microg/kg/min; 6-9: 0.93 +/- 0.54; > or =10: 0.40 +/- 0.27; p < 0.001). Total SOFA score at the time of argatroban initiation was independently associated with an argatroban dosage less than 0.75 microg/kg/min (OR 1.5, 95% CI 1.2 to 1.8; p < 0.001). Adverse events were similar between groups. CONCLUSIONS: Critically ill patients with single or multiple organ failure require lower therapeutic argatroban dosages compared with noncritically ill patients. Because of an inverse relationship with SOFA score, initial argatroban dosage in critically ill patients should be based on the presence and magnitude of organ failure.

Utility of bilateral bronchoalveolar lavage for the diagnosis of ventilator-associated pneumonia in critically ill surgical patients.

BACKGROUND: Bronchoalveolar lavage (BAL) is recommended to facilitate the diagnosis of ventilator-associated pneumonia (VAP). It is unclear if bilateral sampling improves the accuracy of BAL. METHODS: Consecutive patients with clinical suspicion for VAP were analyzed. All patients underwent bilateral BAL. A threshold of >10(4) colony-forming units (cfu)/mL was diagnostic for VAP (VAP positive). Samples were concordant if the organism(s) and thresholds from both lungs were diagnostically consistent. Organisms 10(4) cfu/mL were considered false-negative samples. RESULTS: Between November 2005 and April 2006, 73 patients were considered clinically suspicious for VAP. Forty-four (60%) patients were VAP positive. Twenty-eight (64%) VAP patients had concordant samples. Overall, there were 15 false-negative samples. Sole use of the unilateral samples to guide treatment would have inappropriately directed antibiotic avoidance and/or discontinuation in 25% of VAP patients. Influence of the chest radiograph was equivocal because of the presence of bilateral infiltrates in 80% of discordant samples. CONCLUSIONS: Bilateral BAL improves the accuracy of bronchoscopy in diagnosing VAP. Unilateral BAL may be insensitive in patients with clinically significant contralateral infection.