Effect on Patient Safety of a Resident Physician Schedule without 24-Hour Shifts.

BACKGROUND: The effects on patient safety of eliminating extended-duration work shifts for resident physicians remain controversial. METHODS: We conducted a multicenter, cluster-randomized, crossover trial comparing two schedules for pediatric resident physicians during their intensive care unit (ICU) rotations: extended-duration work schedules that included shifts of 24 hours or more (control schedules) and schedules that eliminated extended shifts and cycled resident physicians through day and night shifts of 16 hours or less (intervention schedules). The primary outcome was serious medical errors made by resident physicians, assessed by intensive surveillance, including direct observation and chart review. RESULTS: The characteristics of ICU patients during the two work schedules were similar, but resident physician workload, described as the mean (±SD) number of ICU patients per resident physician, was higher during the intervention schedules than during the control schedules (8.8±2.8 vs. 6.7±2.2). Resident physicians made more serious errors during the intervention schedules than during the control schedules (97.1 vs. 79.0 per 1000 patient-days; relative risk, 1.53; 95% confidence interval [CI], 1.37 to 1.72; P<0.001). The number of serious errors unitwide were likewise higher during the intervention schedules (181.3 vs. 131.5 per 1000 patient-days; relative risk, 1.56; 95% CI, 1.43 to 1.71). There was wide variability among sites, however; errors were lower during intervention schedules than during control schedules at one site, rates were similar during the two schedules at two sites, and rates were higher during intervention schedules than during control schedules at three sites. In a secondary analysis that was adjusted for the number of patients per resident physician as a potential confounder, intervention schedules were no longer associated with an increase in errors. CONCLUSIONS: Contrary to our hypothesis, resident physicians who were randomly assigned to schedules that eliminated extended shifts made more serious errors than resident physicians assigned to schedules with extended shifts, although the effect varied by site. The number of ICU patients cared for by each resident physician was higher during schedules that eliminated extended shifts. (Funded by the National Heart, Lung, and Blood Institute; ROSTERS ClinicalTrials.gov number, NCT02134847.).

Pediatric Resident Engagement With an Online Critical Care Curriculum During the Intensive Care Rotation.

OBJECTIVES: Residents are often assigned online learning materials as part of blended learning models, superimposed on other patient care and learning demands. Data that describe the time patterns of when residents interact with online learning materials during the ICU rotation are lacking. We describe resident engagement with assigned online curricula related to time of day and ICU clinical schedules, using website activity data. DESIGN: Prospective cohort study examining curriculum completion data and cross-referencing timestamps for pre- and posttest attempts with resident schedules to determine the hours that they accessed the curriculum and whether or not they were scheduled for clinical duty. Residents at each site were cohorted based on two differing clinical schedules-extended duration (>24 hr) versus shorter (maximum 16 hr) shifts. SETTING: Two large academic children's hospitals. SUBJECTS: Pediatric residents rotating in the PICU from July 2013 to June 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One-hundred and fifty-seven pediatric residents participated in the study. The majority of residents (106/157; 68%) completed the curriculum, with no statistically significant association between overall curriculum completion and schedule cohort at either site. Residents made more test attempts at nighttime between 6 PM and 6 AM (1,824/2,828; 64%) regardless of whether they were scheduled for clinical duty. Approximately two thirds of test attempts (1,785/2,828; 63%) occurred when residents were not scheduled to work, regardless of time of day. Forty-two percent of all test attempts (1,199/2,828) occurred between 6 PM and 6 AM while off-duty, with 12% (342/2,828) occurring between midnight and 6 AM. CONCLUSIONS: Residents rotating in the ICU completed online learning materials mainly during nighttime and off-duty hours, including usage between midnight and 6 AM while off-duty. Increasing nighttime and off-duty workload may have implications for educational design and trainee wellness, particularly during busy, acute clinical rotations, and warrants further examination.

A novel workplace-based assessment for competency-based decisions and learner feedback.

BACKGROUND: Increased recognition of the importance of competency-based education and assessment has led to the need for practical and reliable methods to assess relevant skills in the workplace. METHODS: A novel milestone-based workplace assessment system was implemented in 15 pediatrics residency programs. The system provided: (1) web-based multisource feedback (MSF) and structured clinical observation (SCO) instruments that could be completed on any computer or mobile device; and (2) monthly feedback reports that included competency-level scores and recommendations for improvement. RESULTS: For the final instruments, an average of five MSF and 3.7 SCO assessment instruments were completed for each of 292 interns; instruments required an average of 4-8 min to complete. Generalizability coefficients >0.80 were attainable with six MSF observations. Users indicated that the new system added value to their existing assessment program; the need to complete the local assessments in addition to the new assessments was identified as a burden of the overall process. CONCLUSIONS: Outcomes - including high participation rates and high reliability compared to what has traditionally been found with workplace-based assessment - provide evidence for the validity of scores resulting from this novel competency-based assessment system. The development of this assessment model is generalizable to other specialties.

Thrombocytopenia-associated multi-organ failure caused by diabetic ketoacidosis.

Thrombocytopenia-associated multi-organ failure (TAMOF) is an increasingly reported entity in the pediatric intensive care unit. The clinical presentation is similar to thrombotic thrombocytopenic purpura, but with no evidence of hemolysis and no schistocytes on peripheral smear. We report a case of TAMOF induced by diabetic ketoacidosis and treated with therapeutic plasma exchange (TPE). Early diagnosis and initiation of TPE significantly decrease the morbidity associated with TAMOF.

Non-typeable Haemophilus influenzae purulent pericarditis in a child with cystic fibrosis.

Early airway colonization and infection with Haemophilus influenzae in children with cystic fibrosis (CF) is common. Although the pathogenicity of non-typeable H. influenzae (NTHi) in patients with CF is controversial, this organism can cause both upper and lower respiratory tract infections. Extra-pulmonary disease, however, is rare. Purulent pericarditis is a suppurative complication of bacterial infection of the pericardial space that can arise as a result of direct extension from an adjacent infection. We describe a case of purulent pericarditis due to NTHi in a young child with CF that developed as a complication of inadequately treated bronchopneumonia.

Integrating education for clinical practice change.

BACKGROUND: Children with chronic medical conditions and their families have significant emotional health concerns, yet paediatricians are often ill-equipped to address these needs. The American Board of Pediatrics launched the Roadmap Project to better support emotional health as part of routine care. We present pilot work in paediatric training programmes to test educational approaches and explore lessons learned. APPROACH: Four institutions implemented Roadmap tools into their paediatric training programmes, either incorporating them into existing educational structures or embedding them into the clinical workplace. One programme utilised an existing longitudinal curriculum, and another incorporated into a block rotation. Two programmes embedded training for residents into a larger programme for the healthcare team within the clinical space, one in outpatient clinics and one in an inpatient service. EVALUATION: Evaluation strategies at each site matched the intended outcomes. Sites working within education programmes evaluated learners, demonstrating increases in resident skills and confidence on pre-/post-self-assessments. Sites embedding tools into the practice context measured changes in the clinical practice of the healthcare team. Despite variability in implementation, all approaches improved trainee skills; sites embedding education into a clinical setting saw greater changes in clinical practice. IMPLICATIONS: Our pilot provided structure yet allowed for flexibility, and all sites improved trainee skills. Engaging the entire healthcare team within practice settings appears advantageous, thus embedding education into clinical practice may be preferable to a separate education programme. Similar to outcomes found in interprofessional education (IPE), educating clinical teams together may be more impactful for cultural shifts needed for changing clinical practice.

Effect of a Novel Mindfulness Curriculum on Burnout During Pediatric Internship: A Cluster Randomized Clinical Trial.

IMPORTANCE: Mindfulness curricula can improve physician burnout, but implementation during residency presents challenges. OBJECTIVE: To examine whether a novel mindfulness curriculum implemented in the first 6 months of internship reduces burnout. DESIGN, SETTING, AND PARTICIPANTS: This pragmatic, multicenter, stratified cluster randomized clinical trial of a mindfulness curriculum randomized 340 pediatric interns to the intervention or control arm within program pairs generated based on program size and region. Fifteen US pediatric training programs participated from June 14, 2017, to February 28, 2019. INTERVENTIONS: The intervention included 7 hour-long sessions of a monthly mindfulness curriculum (Mindfulness Intervention for New Interns) and a monthly mindfulness refresher implemented during internship. The active control arm included monthly 1-hour social lunches. MAIN OUTCOMES AND MEASURES: The primary outcome was emotional exhaustion (EE) as measured by the Maslach Burnout Inventory 9-question EE subscale (range, 7-63; higher scores correspond to greater perceived burnout). Secondary outcomes were depersonalization, personal accomplishment, and burnout. The study assessed mindfulness with the Five Facet Mindfulness Questionnaire and empathy with the Interpersonal Reactivity Index subscales of perspective taking and empathetic concern. Surveys were implemented at baseline, month 6, and month 15. RESULTS: Of the 365 interns invited to participate, 340 (93.2%; 255 [75.0%] female; 51 [15.0%] 30 years or older) completed surveys at baseline; 273 (74.8%) also participated at month 6 and 195 (53.4%) at month 15. Participants included 194 (57.1%) in the Mindfulness Intervention for New Interns and 146 (42.9%) in the control arm. Analyses were adjusted for baseline outcome measures. Both arms' EE scores were higher at 6 and 15 months than at baseline, but EE did not significantly differ by arm in multivariable analyses (6 months: 35.4 vs 32.4; adjusted difference, 3.03; 95% CI, -0.14 to 6.21; 15 months: 33.8 vs 32.9; adjusted difference, 1.42; 95% CI, -2.42 to 5.27). None of the 6 secondary outcomes significantly differed by arm at month 6 or month 15. CONCLUSIONS AND RELEVANCE: A novel mindfulness curriculum did not significantly affect EE, burnout, empathy, or mindfulness immediately or 9 months after curriculum implementation. These findings diverge from prior nonrandomized studies of mindfulness interventions, emphasizing the importance of rigorous study design and suggesting that additional study is needed to develop evidence-based methods to reduce trainee burnout. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03148626.

Validation of a gene expression-based subclassification strategy for pediatric septic shock.

OBJECTIVE: Septic shock heterogeneity has important implications for clinical trial implementation and patient management. We previously addressed this heterogeneity by identifying three putative subclasses of children with septic shock based exclusively on a 100-gene expression signature. Here we attempted to prospectively validate the existence of these gene expression-based subclasses in a validation cohort. DESIGN: Prospective observational study involving microarray-based bioinformatics. SETTING: Multiple pediatric intensive care units in the United States. PATIENTS: Separate derivation (n = 98) and validation (n = 82) cohorts of children with septic shock. INTERVENTIONS: None other than standard care. MEASUREMENTS AND MAIN RESULTS: Gene expression mosaics of the 100 class-defining genes were generated for 82 individual patients in the validation cohort. Using computer-based image analysis, patients were classified into one of three subclasses ("A," "B," or "C") based on color and pattern similarity relative to reference mosaics generated from the original derivation cohort. After subclassification, the clinical database was mined for phenotyping. Subclass A patients had higher illness severity relative to subclasses B and C as measured by maximal organ failure, fewer intensive care unit-free days, and a higher Pediatric Risk of Mortality score. Patients in subclass A were characterized by repression of genes corresponding to adaptive immunity and glucocorticoid receptor signaling. Separate subclass assignments were conducted by 21 individual clinicians using visual inspection. The consensus classification of the clinicians had modest agreement with the computer algorithm. CONCLUSIONS: We have validated the existence of subclasses of children with septic shock based on a biologically relevant, 100-gene expression signature. The subclasses have relevant clinical differences.

Extended Work Shifts and Neurobehavioral Performance in Resident-Physicians.

OBJECTIVES: Extended-duration work rosters (EDWRs) with shifts of 24+ hours impair performance compared with rapid cycling work rosters (RCWRs) that limit shifts to 16 hours in postgraduate year (PGY) 1 resident-physicians. We examined the impact of a RCWR on PGY 2 and PGY 3 resident-physicians. METHODS: Data from 294 resident-physicians were analyzed from a multicenter clinical trial of 6 US PICUs. Resident-physicians worked 4-week EDWRs with shifts of 24+ hours every third or fourth shift, or an RCWR in which most shifts were ≤16 consecutive hours. Participants completed a daily sleep and work log and the 10-minute Psychomotor Vigilance Task and Karolinska Sleepiness Scale 2 to 5 times per shift approximately once per week as operational demands allowed. RESULTS: Overall, the mean (± SE) number of attentional failures was significantly higher (P =.01) on the EDWR (6.8 ± 1.0) compared with RCWR (2.9 ± 0.7). Reaction time and subjective alertness were also significantly higher, by ∼18% and ∼9%, respectively (both P <.0001). These differences were sustained across the 4-week rotation. Moreover, attentional failures were associated with resident-physician-related serious medical errors (SMEs) (P =.04). Although a higher rate of SMEs was observed under the RCWR, after adjusting for workload, RCWR had a protective effect on the rate of SMEs (rate ratio 0.48 [95% confidence interval: 0.30-0.77]). CONCLUSIONS: Performance impairment due to EDWR is improved by limiting shift duration. These data and their correlation with SME rates highlight the impairment of neurobehavioral performance due to extended-duration shifts and have important implications for patient safety.

Toward a clinically feasible gene expression-based subclassification strategy for septic shock: proof of concept.

OBJECTIVE: To develop a clinically feasible stratification strategy for pediatric septic shock, using gene expression mosaics and a 100-gene signature representing the first 24 hrs of admission to the pediatric intensive care unit. DESIGN: Prospective, observational study involving microarray-based bioinformatics. SETTING: Multiple pediatric intensive care units in the United States. PATIENTS: Ninety-eight children with septic shock. INTERVENTIONS: None other than standard care. MEASUREMENTS AND MAIN RESULTS: Patients were classified into three previously published, genome-wide, expression-based subclasses (subclasses A, B, and C) having clinically relevant phenotypic differences. The class-defining 100-gene signature was depicted for each individual patient, using mosaics generated by the Gene Expression Dynamics Inspector (GEDI). Composite mosaics were generated representing the average expression patterns for each of the three subclasses. Nine individual clinicians served as blinded evaluators. Each evaluator was shown the 98 individual patient mosaics and asked to classify each patient into one of the three subclasses, using the composite mosaics as the reference point. The respective sensitivities, specificities, positive predictive values, and negative predictive values of the subclassification strategy were ≥ 4% across the three subclasses. The classification strategy also generated positive likelihood ratios of ≥ 6.8 and negative likelihood ratios of ≤ .2 across the three subclasses. The κ coefficient across all possible interevaluator comparisons was 0.81. CONCLUSIONS: We have provided initial evidence (proof of concept) for a clinically feasible and robust stratification strategy for pediatric septic shock based on a 100-gene signature and gene expression mosaics.

Extracellular Hsp72, an endogenous DAMP, is released by virally infected airway epithelial cells and activates neutrophils via Toll-like receptor (TLR)-4.

BACKGROUND: Neutrophils play an important role in the pathophysiology of RSV, though RSV does not appear to directly activate neutrophils in the lower airways. Therefore locally produced cytokines or other molecules released by virally-infected airway epithelial cells are likely responsible for recruiting and activating neutrophils. Heat shock proteins (HSPs) are generally regarded as intracellular proteins acting as molecular chaperones; however, HSP72 can also be released from cells, and the implications of this release are not fully understood. METHODS: Human bronchial epithelial cells (16HBE14o-) were infected with RSV and Hsp72 levels were measured by Western blot and ELISA. Tracheal aspirates were obtained from critically ill children infected with RSV and analyzed for Hsp72 levels by ELISA. Primary human neutrophils and differentiated HL-60 cells were cultured with Hsp72 and supernatants analyzed for cytokine production. In some cases, cells were pretreated with polymyxin B prior to treatment with Hsp72. IkappaBalpha was assessed by Western blot and EMSA's were performed to determine NF-kappaB activation. HL-60 cells were pretreated with neutralizing antibody against TLR4 prior to Hsp72 treatment. Neutrophils were harvested from the bone marrow of wild type or TLR4-deficient mice prior to treatment with Hsp72. RESULTS: Infection of 16HBE14o- with RSV showed an induction of intracellular Hsp72 levels as well as extracellular release of Hsp72. Primary human neutrophils from normal donors and differentiated HL-60 cells treated with increasing concentrations of Hsp72 resulted in increased cytokine (IL-8 and TNFalpha) production. This effect was independent of the low levels of endotoxin in the Hsp72 preparation. Hsp72 mediated cytokine production via activation of NF-kappaB translocation and DNA binding. Using bone marrow-derived neutrophils from wild type and TLR4-mutant mice, we showed that Hsp72 directly activates neutrophil-derived cytokine production via the activation of TLR4. CONCLUSION: Collectively these data suggest that extracellular Hsp72 is released from virally infected airway epithelial cells resulting in the recruitment and activation of neutrophils.

Design and recruitment of the randomized order safety trial evaluating resident-physician schedules (ROSTERS) study.

INTRODUCTION: While the Accreditation Council for Graduate Medical Education limited first year resident-physicians to 16 consecutive work hours from 2011 to 2017, resident-physicians in their second year or higher were permitted to work up to 28 h consecutively. This paper describes the Randomized Order Safety Trial Evaluating Resident-physician Schedules (ROSTERS) study, a clustered-randomized crossover clinical trial designed to evaluate the effectiveness of eliminating traditional shifts of 24 h or longer for second year or higher resident-physicians in pediatric intensive care units (PICUs). METHODS: ROSTERS was a multi-center non-blinded trial in 6 PICUs at US academic medical centers. The primary aim was to compare patient safety between the extended duration work roster (EDWR), which included shifts ≥24 h, and a rapidly cycling work roster (RCWR), where shifts were limited to a maximum of 16 h. Information on potential medical errors was gathered and used for classification by centrally trained physician reviewers who were blinded to the study arm. Secondary aims were to assess the relationship of the study arm to resident-physician sleep duration, work hours and neurobehavioral performance. RESULTS: The study involved 6577 patients with a total of 38,821 patient days (n = 18,749 EDWR, n = 20,072 RCWR). There were 413 resident-physician rotations included in the study (n = 203 EDWR, n = 210 RCWR). Resident-physician questionnaire data were over 95% complete. CONCLUSIONS: Results from data collected in the ROSTERS study will be evaluated for the impact of resident-physician schedule roster on patient safety outcomes in PICUs, and will allow for examination of a number of secondary outcome measures. ClinicalTrials.gov Identifier: NCT02134847.

Effects on resident work hours, sleep duration, and work experience in a randomized order safety trial evaluating resident-physician schedules (ROSTERS).

STUDY OBJECTIVES: We compared resident physician work hours and sleep in a multicenter clustered-randomized crossover clinical trial that randomized resident physicians to an Extended Duration Work Roster (EDWR) with extended-duration (≥24 hr) shifts or a Rapidly Cycling Work Roster (RCWR), in which scheduled shift lengths were limited to 16 or fewer consecutive hours. METHODS: Three hundred two resident physicians were enrolled and completed 370 1 month pediatric intensive care unit rotations in six US academic medical centers. Sleep was objectively estimated with wrist-worn actigraphs. Work hours and subjective sleep data were collected via daily electronic diary. RESULTS: Resident physicians worked fewer total hours per week during the RCWR compared with the EDWR (61.9 ± 4.8 versus 68.4 ± 7.4, respectively; p < 0.0001). During the RCWR, 73% of work hours occurred within shifts of ≤16 consecutive hours. In contrast, during the EDWR, 38% of work hours occurred on shifts of ≤16 consecutive hours. Resident physicians obtained significantly more sleep per week on the RCWR (52.9 ± 6.0 hr) compared with the EDWR (49.1 ± 5.8 hr, p < 0.0001). The percentage of 24 hr intervals with less than 4 hr of actigraphically measured sleep was 9% on the RCWR and 25% on the EDWR (p < 0.0001). CONCLUSIONS: RCWRs were effective in reducing weekly work hours and the occurrence of >16 consecutive hour shifts, and improving sleep duration of resident physicians. Although inclusion of the six operational healthcare sites increases the generalizability of these findings, there was heterogeneity in schedule implementation. Additional research is needed to optimize scheduling practices allowing for sufficient sleep prior to all work shifts.Clinical Trial: Multicenter Clinical Trial of Limiting Resident Work Hours on ICU Patient Safety (ROSTERS), https://clinicaltrials.gov/ct2/show/NCT02134847.

The Pediatrics Milestones Assessment Pilot: Development of Workplace-Based Assessment Content, Instruments, and Processes.

PURPOSE: To report on the development of content and user feedback regarding the assessment process and utility of the workplace-based assessment instruments of the Pediatrics Milestones Assessment Pilot (PMAP). METHOD: One multisource feedback instrument and two structured clinical observation instruments were developed and refined by experts in pediatrics and assessment to provide evidence for nine competencies based on the Pediatrics Milestones (PMs) and chosen to inform residency program faculty decisions about learners' readiness to serve as pediatric interns in the inpatient setting. During the 2012-2013 PMAP study, 18 U.S. pediatric residency programs enrolled interns and subinterns. Faculty, residents, nurses, and other observers used the instruments to assess learner performance through direct observation during a one-month rotation. At the end of the rotation, data were aggregated for each learner, milestone levels were assigned using a milestone classification form, and feedback was provided to learners. Learners and site leads were surveyed and/or interviewed about their experience as participants. RESULTS: Across the sites, 2,338 instruments assessing 239 learners were completed by 630 unique observers. Regarding end-of-rotation feedback, 93% of learners (128/137) agreed the assessments and feedback "helped me understand how those with whom I work perceive my performance," and 85% (117/137) agreed they were "useful for constructing future goals or identifying a developmental path." Site leads identified several benefits and challenges to the assessment process. CONCLUSIONS: PM-based instruments used in workplace-based assessment provide a meaningful and acceptable approach to collecting evidence of learner competency development. Learners valued feedback provided by PM-based assessment.

Surfactant biology and clinical application.

There is strong evidence that alterations in the pulmonary surfactant system play an important role in the pathophysiology of lung disease, including ARDS . Although it is still unclear whether mortality and morbidity of ARDS will be reduced, surfactant replacement therapy has been shown to improve oxygenation, improve lung compliance, and decrease the need for ventilatory support. The critical need for more standardized studies with one type of intratracheal surfactant and uniform measurements of surfactant proteins and phospholipids by BAL is evident. Further studies will also be needed to elucidate the optimal timing and dosage regimen for different disease processes. Some evidence supports the measurements of surfactant protein levels as markers for predicting the onset and outcome of ARDS and perhaps providing a window for early treatment of patients at risk to develop ARDS. Continued investigation into the role of surfactant in the immune regulation of the lung may also provide additional information to support the efficacy of surfactant replacement in lung disease.

Biological activity of truncated C-terminus human heat shock protein 72.

Heat shock protein 72 (Hsp72), a canonical intracellular molecular chaperone, may also function as an extracellular danger signal for the innate immune system. To further delineate the biological role of Hsp72 in the innate immune system, we generated two truncated versions of the full length human Hsp72 (N-terminus Hsp72, amino acids 1-430; and C-terminus Hsp72 amino acids 420-641) and directly compared their ability to activate cells from the macrophage/monocyte lineage. In RAW 264.7 macrophages transfected with a NF-κB-dependent luciferase reporter plasmid, C-terminus Hsp72 was a more potent inducer of NF-κB activity than N-terminus Hsp72, and this effect did not seem to be secondary to endotoxin contamination. C-terminus Hsp72-mediated activation of the NF-κB pathway was corroborated by increased activation of IκB kinase, degradation of IκBα, and increased NF-κB-DNA binding. C-terminus Hsp72 was a more potent inducer of tumor necrosis factor-α (TNFα) expression in RAW 264.7 macrophages and in primary murine peritoneal macrophages from wild-type mice. C-terminus Hsp72 did not induce TNFα expression in primary murine peritoneal macrophages from Toll-like receptor (TLR4) mutant mice, indicating a role for TLR4. In human THP-1 mononuclear cells, C-terminus Hsp72 induced tolerance to subsequent LPS stimulation, whereas N-terminus Hsp72 did not induce tolerance. Finally, control experiments using equimolar amounts of N-terminus or C-terminus Hsp72 demonstrated a higher biological potency for C-terminus Hsp72. These data demonstrate that the ability of human Hsp72 to serve as an activator for cells of the macrophage/monocyte lineage primarily lies in the C-terminus region spanning amino acids 420-641.

Induction of endotoxin tolerance enhances bacterial clearance and survival in murine polymicrobial sepsis.

The fundamental mechanisms that underlie endotoxin tolerance remain to be elucidated, and the clinical significance of endotoxin tolerance in the context of active systemic infection remains in question. We hypothesized that the endotoxin tolerance phenotype would result in decreased inflammation at the expense of altered bacterial clearance and, thus, higher mortality in a murine model of polymicrobial sepsis induced by cecal ligation and puncture (CLP). Endotoxin tolerance was induced in C57Bl/6 mice with 5 mg/kg LPS or vehicle 18 h before subsequent CLP. Lung tissue, peritoneal fluid, and blood were collected at 1, 3, 6, and 18 h after surgery for subsequent analysis. Peritoneal macrophages were isolated for ex vivo phagocytosis assay. In separate experiments, mice were allowed to recover, and survival was monitored for 7 days. Endotoxin tolerance attenuated plasma TNF-alpha and IL-6 at 6 h after CLP. Peritoneal fluid cytokines were significantly attenuated as well. Endotoxin tolerance significantly improved bacterial clearance in both blood and peritoneal fluid after CLP. Similarly, ex vivo phagocytosis by primary peritoneal macrophages and RAW264.7 murine peritoneal macrophages was significantly improved after induction of the endotoxin tolerance phenotype. Contrary to our original hypothesis, we conclude that endotoxin tolerance significantly attenuates the host inflammatory response, augments bacterial clearance, and improves survival in this murine model of polymicrobial sepsis.