From ICU Syndromes to ICU Subphenotypes: Consensus Report and Recommendations for Developing Precision Medicine in the ICU.

Critical care uses syndromic definitions to describe patient groups for clinical practice and research. There is growing recognition that a "precision medicine" approach is required and that integrated biologic and physiologic data identify reproducible subpopulations that may respond differently to treatment. This article reviews the current state of the field and considers how to successfully transition to a precision medicine approach. To impact clinical care, identification of subpopulations must do more than differentiate prognosis. It must differentiate response to treatment, ideally by defining subgroups with distinct functional or pathobiological mechanisms (endotypes). There are now multiple examples of reproducible subpopulations of sepsis, acute respiratory distress syndrome, and acute kidney or brain injury described using clinical, physiological, and/or biological data. Many of these subpopulations have demonstrated the potential to define differential treatment response, largely in retrospective studies, and that the same treatment-responsive subpopulations may cross multiple clinical syndromes (treatable traits). To bring about a change in clinical practice, a precision medicine approach must be evaluated in prospective clinical studies requiring novel adaptive trial designs. Several such studies are underway, but there are multiple challenges to be tackled. Such subpopulations must be readily identifiable and be applicable to all critically ill populations around the world. Subdividing clinical syndromes into subpopulations will require large patient numbers. Global collaboration of investigators, clinicians, industry, and patients over many years will therefore be required to transition to a precision medicine approach and ultimately realize treatment advances seen in other medical fields.

Evolving Management Practices for Early Sepsis-induced Hypoperfusion: A Narrative Review.

Sepsis causes significant morbidity and mortality worldwide. Resuscitation is a cornerstone of management. This review covers five areas of evolving practice in the management of early sepsis-induced hypoperfusion: fluid resuscitation volume, timing of vasopressor initiation, resuscitation targets, route of vasopressor administration, and use of invasive blood pressure monitoring. For each topic, we review the seminal evidence, discuss the evolution of practice over time, and highlight questions for additional research. Intravenous fluids are a core component of early sepsis resuscitation. However, with growing concerns about the harms of fluid, practice is evolving toward smaller-volume resuscitation, which is often paired with earlier vasopressor initiation. Large trials of fluid-restrictive, vasopressor-early strategies are providing more information about the safety and potential benefit of these approaches. Lowering blood pressure targets is a means to prevent fluid overload and reduce exposure to vasopressors; mean arterial pressure targets of 60-65 mm Hg appear to be safe, at least in older patients. With the trend toward earlier vasopressor initiation, the need for central administration of vasopressors has been questioned, and peripheral vasopressor use is increasing, although it is not universally accepted. Similarly, although guidelines suggest the use of invasive blood pressure monitoring with arterial catheters in patients receiving vasopressors, blood pressure cuffs are less invasive and often sufficient. Overall, the management of early sepsis-induced hypoperfusion is evolving toward fluid-sparing and less-invasive strategies. However, many questions remain, and additional data are needed to further optimize our approach to resuscitation.

Electric impedance tomography-guided PEEP titration reduces mechanical power in ARDS: a randomized crossover pilot trial.

BACKGROUND: In patients with acute respiratory distress syndrome undergoing mechanical ventilation, positive end-expiratory pressure (PEEP) can lead to recruitment or overdistension. Current strategies utilized for PEEP titration do not permit the distinction. Electric impedance tomography (EIT) detects and quantifies the presence of both collapse and overdistension. We investigated whether using EIT-guided PEEP titration leads to decreased mechanical power compared to high-PEEP/FiO2 tables. METHODS: A single-center, randomized crossover pilot trial comparing EIT-guided PEEP selection versus PEEP selection using the High-PEEP/FiO2 table in patients with moderate-severe acute respiratory distress syndrome. The primary outcome was the change in mechanical power after each PEEP selection strategy. Secondary outcomes included changes in the 4 × driving pressure + respiratory rate (4 ΔP, + RR index) index, driving pressure, plateau pressure, PaO2/FiO2 ratio, and static compliance. RESULTS: EIT was consistently associated with a decrease in mechanical power compared to PEEP/FiO2 tables (mean difference - 4.36 J/min, 95% CI - 6.7, - 1.95, p = 0.002) and led to lower values in the 4ΔP + RR index (- 11.42 J/min, 95% CI - 19.01, - 3.82, p = 0.007) mainly driven by a decrease in the elastic-dynamic power (- 1.61 J/min, - 2.99, - 0.22, p = 0.027). The elastic-static and resistive powers were unchanged. Similarly, EIT led to a statistically significant change in set PEEP (- 2 cmH2O, p = 0.046), driving pressure, (- 2.92 cmH2O, p = 0.003), peak pressure (- 6.25 cmH2O, p = 0.003), plateau pressure (- 4.53 cmH2O, p = 0.006), and static respiratory system compliance (+ 7.93 ml/cmH2O, p = 0.008). CONCLUSIONS: In patients with moderate-severe acute respiratory distress syndrome, EIT-guided PEEP titration reduces mechanical power mainly through a reduction in elastic-dynamic power. Trial registration This trial was prospectively registered on Clinicaltrials.gov (NCT03793842) on January 4th, 2019.

External Validation of an Acute Respiratory Distress Syndrome Prediction Model Using Radiology Reports.

OBJECTIVES: Acute respiratory distress syndrome is frequently under recognized and associated with increased mortality. Previously, we developed a model that used machine learning and natural language processing of text from radiology reports to identify acute respiratory distress syndrome. The model showed improved performance in diagnosing acute respiratory distress syndrome when compared to a rule-based method. In this study, our objective was to externally validate the natural language processing model in patients from an independent hospital setting. DESIGN: Secondary analysis of data across five prospective clinical studies. SETTING: An urban, tertiary care, academic hospital. PATIENTS: Adult patients admitted to the medical ICU and at-risk for acute respiratory distress syndrome. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The natural language processing model was previously derived and internally validated in burn, trauma, and medical patients at Loyola University Medical Center. Two machine learning models were examined with the following text features from qualifying radiology reports: 1) word representations (n-grams) and 2) standardized clinical named entity mentions mapped from the National Library of Medicine Unified Medical Language System. The models were externally validated in a cohort of 235 patients at the University of Chicago Medicine, among which 110 (47%) were diagnosed with acute respiratory distress syndrome by expert annotation. During external validation, the n-gram model demonstrated good discrimination between acute respiratory distress syndrome and nonacute respiratory distress syndrome patients (C-statistic, 0.78; 95% CI, 0.72-0.84). The n-gram model had a higher discrimination for acute respiratory distress syndrome when compared with the standardized named entity model, although not statistically significant (C-statistic 0.78 vs 0.72; p = 0.09). The most important features in the model had good face validity for acute respiratory distress syndrome characteristics but differences in frequencies did occur between hospital settings. CONCLUSIONS: Our computable phenotype for acute respiratory distress syndrome had good discrimination in external validation and may be used by other health systems for case-identification. Discrepancies in feature representation are likely due to differences in characteristics of the patient cohorts.

Understanding How Clinicians Personalize Fluid and Vasopressor Decisions in Early Sepsis Management.

Importance: Recent sepsis trials suggest that fluid-liberal vs fluid-restrictive resuscitation has similar outcomes. These trials used generalized approaches to resuscitation, and little is known about how clinicians personalize fluid and vasopressor administration in practice. Objective: To understand how clinicians personalize decisions about resuscitation in practice. Design, Setting, and Participants: This survey study of US clinicians in the Society of Critical Care Medicine membership roster was conducted from November 2022 to January 2023. Surveys contained 10 vignettes of patients with sepsis where pertinent clinical factors (eg, fluid received and volume status) were randomized. Respondents selected the next steps in management. Data analysis was conducted from February to September 2023. Exposure: Online Qualtrics clinical vignette survey. Main Outcomes and Measures: Using multivariable logistic regression, the associations of clinical factors with decisions about fluid administration, vasopressor initiation, and vasopressor route were tested. Results are presented as adjusted proportions with 95% CIs. Results: Among 11 203 invited clinicians, 550 (4.9%; 261 men [47.5%] and 192 women [34.9%]; 173 with >15 years of practice [31.5%]) completed at least 1 vignette and were included. A majority were physicians (337 respondents [61.3%]) and critical care trained (369 respondents [67.1%]). Fluid volume already received by a patient was associated with resuscitation decisions. After 1 L of fluid, an adjusted 82.5% (95% CI, 80.2%-84.8%) of respondents prescribed additional fluid and an adjusted 55.0% (95% CI, 51.9%-58.1%) initiated vasopressors. After 5 L of fluid, an adjusted 17.5% (95% CI, 15.1%-19.9%) of respondents prescribed more fluid while an adjusted 92.7% (95% CI, 91.1%-94.3%) initiated vasopressors. More respondents prescribed fluid when the patient examination found dry vs wet (ie, overloaded) volume status (adjusted proportion, 66.9% [95% CI, 62.5%-71.2%] vs adjusted proportion, 26.5% [95% CI, 22.3%-30.6%]). Medical history, respiratory status, lactate trend, and acute kidney injury had small associations with fluid and vasopressor decisions. In 1023 of 1127 vignettes (90.8%) where the patient did not have central access, respondents were willing to start vasopressors through a peripheral intravenous catheter. In cases where patients were already receiving peripheral norepinephrine, respondents were more likely to place a central line at higher norepinephrine doses of 0.5 µg/kg/min (adjusted proportion, 78.0%; 95% CI, 74.7%-81.2%) vs 0.08 µg/kg/min (adjusted proportion, 25.2%; 95% CI, 21.8%-28.5%) and after 24 hours (adjusted proportion, 59.5%; 95% CI, 56.6%-62.5%) vs 8 hours (adjusted proportion, 47.1%; 95% CI, 44.0%-50.1%). Conclusions and Relevance: These findings suggest that fluid volume received is the predominant factor associated with ongoing fluid and vasopressor decisions, outweighing many other clinical factors. Peripheral vasopressor use is common. Future studies aimed at personalizing resuscitation must account for fluid volumes and should incorporate specific tools to help clinicians personalize resuscitation.

Use and Outcomes of Peripheral Vasopressors in Early Sepsis-Induced Hypotension Across Michigan Hospitals: A Retrospective Cohort Study.

BACKGROUND: Vasopressors traditionally are administered via central access, but newer data suggest that peripheral administration may be safe and may avoid delays and complications associated with central line placement. RESEARCH QUESTION: How commonly are vasopressors initiated through peripheral IV lines in routine practice? Is vasopressor initiation route associated with in-hospital mortality? STUDY DESIGN AND METHODS: This retrospective cohort study included adults hospitalized with sepsis (November 2020-September 2022) at 29 hospitals in the Michigan Hospital Medicine Safety Consortium, a Collaborative Quality Initiative sponsored by Blue Cross Blue Shield of Michigan. We assessed route of early vasopressor initiation, factors and outcomes associated with peripheral initiation, and timing of central line placement. RESULTS: Five hundred ninety-four patients received vasopressors within 6 h of hospital arrival and were included in this study. Peripheral vasopressor initiation was common (400/594 [67.3%]). Patients with peripheral vs central initiation were similar; BMI was the only patient factor associated independently with initiation route (adjusted OR [aOR] of peripheral initiation [per 1-kg/m2 increase], 0.98; 95% CI, 0.97-1.00; P = .015). The specific hospital showed a large impact on initiation route (median OR, 2.19; 95% CI, 1.31-3.07). Compared with central initiation, peripheral initiation was faster (median, 2.5 h vs 2.7 h from hospital arrival; P = .002), but was associated with less initial norepinephrine use (84.3% vs 96.8%; P = .001). We found no independent association between initiation route and in-hospital mortality (32.3% vs 42.2%; aOR, 0.66; 95% CI, 0.39-1.12). No tissue injury from peripheral vasopressors was documented. Of patients with peripheral initiation, 135 of 400 patients (33.8%) never received a central line. INTERPRETATION: Peripheral vasopressor initiation was common across Michigan hospitals and had practical benefits, including expedited vasopressor administration and avoidance of central line placement in one-third of patients. However, the findings of wide practice variation that was not explained by patient case mix and lower use of first-line norepinephrine with peripheral administration suggest that additional standardization may be needed.

Development and Validation of the Hospital Medicine Safety Sepsis Initiative Mortality Model.

BACKGROUND: When comparing outcomes after sepsis, it is essential to account for patient case mix to make fair comparisons. We developed a model to assess risk-adjusted 30-day mortality in the Michigan Hospital Medicine Safety sepsis initiative (HMS-Sepsis). RESEARCH QUESTION: Can HMS-Sepsis registry data adequately predict risk of 30-day mortality? Do performance assessments using adjusted vs unadjusted data differ? STUDY DESIGN AND METHODS: Retrospective cohort of community-onset sepsis hospitalizations in the HMS-Sepsis registry (April 2022-September 2023), with split derivation (70%) and validation (30%) cohorts. We fit a risk-adjustment model (HMS-Sepsis mortality model) incorporating acute physiologic, demographic, and baseline health data and assessed model performance using concordance (C) statistics, Brier scores, and comparisons of predicted vs observed mortality by deciles of risk. We compared hospital performance (first quintile, middle quintiles, fifth quintile) using observed vs adjusted mortality to understand the extent to which risk adjustment impacted hospital performance assessment. RESULTS: Among 17,514 hospitalizations from 66 hospitals during the study period, 12,260 hospitalizations (70%) were used for model derivation and 5,254 hospitalizations (30%) were used for model validation. Thirty-day mortality for the total cohort was 19.4%. The final model included 13 physiologic variables, two physiologic interactions, and 16 demographic and chronic health variables. The most significant variables were age, metastatic solid tumor, temperature, altered mental status, and platelet count. The model C statistic was 0.82 for the derivation cohort, 0.81 for the validation cohort, and ≥ 0.78 for all subgroups assessed. Overall calibration error was 0.0%, and mean calibration error across deciles of risk was 1.5%. Standardized mortality ratios yielded different assessments than observed mortality for 33.9% of hospitals. INTERPRETATION: The HMS-Sepsis mortality model showed strong discrimination and adequate calibration and reclassified one-third of hospitals to a different performance category from unadjusted mortality. Based on its strong performance, the HMS-Sepsis mortality model can aid in fair hospital benchmarking, assessment of temporal changes, and observational causal inference analysis.

High-Flow Nasal Cannula Versus Noninvasive Ventilation as Initial Treatment in Acute Hypoxia: A Propensity Score-Matched Study.

IMPORTANCE: Patients presenting to the emergency department (ED) with hypoxemia often have mixed or uncertain causes of respiratory failure. The optimal treatment for such patients is unclear. Both high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) are used. OBJECTIVES: We sought to compare the effectiveness of initial treatment with HFNC versus NIV for acute hypoxemic respiratory failure. DESIGN SETTING AND PARTICIPANTS: We conducted a retrospective cohort study of patients with acute hypoxemic respiratory failure treated with HFNC or NIV within 24 hours of arrival to the University of Michigan adult ED from January 2018 to December 2022. We matched patients 1:1 using a propensity score for odds of receiving NIV. MAIN OUTCOMES AND MEASURES: The primary outcome was major adverse pulmonary events (28-d mortality, ventilator-free days, noninvasive respiratory support hours) calculated using a win ratio. RESULTS: A total of 1154 patients were included. Seven hundred twenty-six (62.9%) received HFNC and 428 (37.1%) received NIV. We propensity score matched 668 of 1154 (57.9%) patients. Patients on NIV versus HFNC had lower 28-day mortality (16.5% vs. 23.4%, p = 0.033) and required noninvasive treatment for fewer hours (median 7.5 vs. 13.5, p < 0.001), but had no difference in ventilator-free days (median [interquartile range]: 28 [26, 28] vs. 28 [10.5, 28], p = 0.199). Win ratio for composite major adverse pulmonary events favored NIV (1.38; 95% CI, 1.15-1.65; p < 0.001). CONCLUSIONS AND RELEVANCE: In this observational study of patients with acute hypoxemic respiratory failure, initial treatment with NIV compared with HFNC was associated with lower mortality and fewer composite major pulmonary adverse events calculated using a win ratio. These findings underscore the need for randomized controlled trials to further understand the impact of noninvasive respiratory support strategies.

Extubation of Patients Receiving Vasopressor Infusions: Results of a Survey on Statewide Practices.

Current guidelines recommend extubation only if a patient is not receiving vasopressor therapy or is receiving minimal doses of vasopressors. However, recent data indicate that extubation of patients receiving higher vasopressor doses may be safe. This study was undertaken to examine practices regarding extubation of patients receiving vasopressor therapy reported by clinician respondents to a survey by the Michigan Health and Hospital Association Keystone Center. One-third of respondents indicated that they would extubate a patient receiving vasopressors, and one-quarter indicated that it depended on the agent used, but more than half reported that their unit did not have a vasopressor use protocol or they did not know whether it did. Practices regarding extubation of patients receiving vasopressor therapy differed significantly by unit type and by role as a direct care provider. These data indicate that patient and clinician factors may drive practice patterns. Additional research to inform guidelines and local protocols is warranted.

High-flow nasal cannula vs non-invasive ventilation in acute hypoxia: Propensity score matched study.

RATIONALE: The optimal treatment for early hypoxemic respiratory failure is unclear, and both high-flow nasal cannula and non-invasive ventilation are used. Determining clinically relevant outcomes for evaluating non-invasive respiratory support modalities remains a challenge. OBJECTIVES: To compare the effectiveness of initial treatment with high-flow nasal cannula versus non-invasive ventilation for acute hypoxemic respiratory failure. METHODS: We conducted a retrospective cohort study of patients with acute hypoxemic respiratory failure treated with high-flow nasal cannula or non-invasive ventilation within 24 hours of Emergency Department arrival (1/2018-12/2022). We matched patients 1:1 using a propensity score for odds of receiving non-invasive ventilation. The primary outcome was major adverse pulmonary events (28-day mortality, ventilator-free days, non-invasive respiratory support hours) calculated using a Win Ratio. MEASUREMENTS AND MAIN RESULTS: 1,265 patients met inclusion criteria. 795 (62.8%) received high-flow oxygen and 470 (37.2%) received non-invasive ventilation. We propensity score matched 736/1,265 (58.2%) patients. There was no difference between non-invasive ventilation vs high-flow nasal cannula in 28-day mortality (17.7% vs 23.1%, p=0.08) or ventilator-free days (median [Interquartile Range]: 28 [25, 28] vs 28 [13, 28], p=0.50), but patients on non-invasive ventilation required treatment for fewer hours (median 7 vs 13, p< 0.001). Win Ratio for composite major adverse pulmonary events favored non-invasive ventilation (1.26, 95%CI 1.06-1.49, p< 0.001). CONCLUSIONS: In this observational study of patients with acute hypoxemic respiratory failure, initial treatment with non-invasive ventilation was superior to high-flow nasal cannula for major pulmonary adverse events. Evaluation of composite outcomes is important in the assessment of respiratory support modalities.

Institutional Structures and Processes to Support Sepsis Care: A Multihospital Study.

OBJECTIVES: To identify opportunities for improving hospital-based sepsis care and to inform an ongoing statewide quality improvement initiative in Michigan. DESIGN: Surveys on hospital sepsis processes, including a self-assessment of practices using a 3-point Likert scale, were administered to 51 hospitals participating in the Michigan Hospital Medicine Safety Consortium, a Collaborative Quality Initiative sponsored by Blue Cross Blue Shield of Michigan, at two time points (2020, 2022). Forty-eight hospitals also submitted sepsis protocols for structured review. SETTING: Multicenter quality improvement consortium. SUBJECTS: Fifty-one hospitals in Michigan. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the included hospitals, 92.2% (n = 47/51) were nonprofit, 88.2% (n = 45/51) urban, 11.8% (n = 6/51) rural, and 80.4% (n = 41/51) teaching hospitals. One hundred percent (n = 51/51) responded to the survey, and 94.1% (n = 48/51) provided a sepsis policy/protocol. All surveyed hospitals used at least one quality improvement approach, including audit/feedback (98.0%, n = 50/51) and/or clinician education (68.6%, n = 35/51). Protocols included the Sepsis-1 (18.8%, n = 9/48) or Sepsis-2 (31.3%, n = 15/48) definitions; none (n = 0/48) used Sepsis-3. All hospitals (n = 51/51) used at least one process to facilitate rapid sepsis treatment, including order sets (96.1%, n = 49/51) and/or stocking of commonly used antibiotics in at least one clinical setting (92.2%, n = 47/51). Treatment protocols included guidance on antimicrobial therapy (68.8%, n = 33/48), fluid resuscitation (70.8%, n = 34/48), and vasopressor administration (62.5%, n = 30/48). On self-assessment, hospitals reported the lowest scores for peridischarge practices, including screening for cognitive impairment (2.0%, n = 1/51 responded "we are good at this") and providing anticipatory guidance (3.9%, n = 2/51). There were no meaningful associations of the Centers for Medicare and Medicaid Services' Severe Sepsis and Septic Shock: Management Bundle performance with differences in hospital characteristics or sepsis policy document characteristics. CONCLUSIONS: Most hospitals used audit/feedback, order sets, and clinician education to facilitate sepsis care. Hospitals did not consistently incorporate organ dysfunction criteria into sepsis definitions. Existing processes focused on early recognition and treatment rather than recovery-based practices.

The Association of Vasopressor Administration through a Midline Catheter with Catheter-related Complications.

Rationale: Little is known about the safety of infusing vasopressors through a midline catheter. Objectives: To evaluate safety outcomes after vasopressor administration through a midline. Methods: We conducted a cohort study of adults admitted to 39 hospitals in Michigan (December 2017-March 2022) who received vasopressors while either a midline or peripherally inserted central catheter (PICC) was in place. Patients receiving vasopressors through a midline were compared with those receiving vasopressors through a PICC and, separately, to those with midlines in place but who received vasopressors through a different catheter. We used descriptive statistics to characterize and compare cohort characteristics. Multivariable mixed effects logistic regression models were fit to determine the association between vasopressor administration through a midline with outcomes, primarily catheter-related complications (bloodstream infection, superficial thrombophlebitis, exit site infection, or catheter occlusion). Results: Our cohort included 287 patients with midlines through which vasopressors were administered, 1,660 with PICCs through which vasopressors were administered, and 884 patients with midlines who received vasopressors through a separate catheter. Age (median [interquartile range]: 68.7 [58.6-75.7], 66.6 [57.1-75.0], and 67.6 [58.7-75.8] yr) and gender (percentage female: 50.5%, 47.3%, and 43.8%) were similar in all groups. The frequency of catheter-related complications was lower in patients with midlines used for vasopressors than PICCs used for vasopressors (5.2% vs. 13.4%; P < 0.001) but similar to midlines with vasopressor administration through a different device (5.2% vs. 6.3%; P = 0.49). After adjustment, administration of vasopressors through a midline was not associated with catheter-related complications compared with PICCs with vasopressors (adjusted odds ratios [aOR], 0.65 [95% confidence interval, 0.31-1.33]; P = 0.23) or midlines with vasopressors elsewhere (aOR, 0.85 [0.46-1.58]; P = 0.59). Midlines used for vasopressors were associated with greater risk of systemic thromboembolism (vs. PICCs with vasopressors: aOR, 2.69 [1.31-5.49]; P = 0.008; vs. midlines with vasopressors elsewhere: aOR, 2.42 [1.29-4.54]; P = 0.008) but not thromboses restricted to the ipsilateral upper extremity (vs. PICCs with vasopressors: aOR, 2.35 [0.83-6.63]; P = 0.10; model did not converge for vs. midlines with vasopressors elsewhere). Conclusions: We found no significant association of vasopressor administration through a midline with catheter-related complications. However, we identified increased odds of systemic (but not ipsilateral upper extremity) venous thromboembolism warranting further evaluation.

A motivational interviewing-based counseling intervention to increase postabortion uptake of contraception: A pilot randomized controlled trial.

OBJECTIVE: To determine if a counseling intervention using the principles of motivational interviewing (MI) would impact uptake of long-acting reversible contraception (LARC) after abortion. METHODS: We conducted a pilot randomized controlled trial comparing an MI-based contraception counseling intervention to only non-standardized counseling. Sixty women 15-29 years-old were randomized. PRIMARY OUTCOME: uptake of LARC within four weeks of abortion. SECONDARY OUTCOMES: uptake of any effective contraceptive, contraceptive use three months after abortion and satisfaction with counseling. Bivariate analysis was used to compare outcomes. RESULTS: In the intervention arm, 65.5% of participants received a long-acting method within four weeks compared to 32.3% in the control arm (p=0.01). Three months after the abortion, differences in LARC use endured (60.0% vs. 30.8%, p=0.05). Uptake and use of any effective method were not statistically different. More women in the intervention arm reported satisfaction with their counseling than women in the control arm (92.0% vs. 65.4%, p=0.04). CONCLUSION: Twice as many women in the MI-based contraception counseling intervention initiated and continued to use LARC compared to women who received only non-standardized counseling. PRACTICE IMPLICATIONS: A contraception counseling session using the principles and skills of motivational interviewing has the potential to impact LARC use after abortion.

Homologous recombination using bacterial artificial chromosomes.

This protocol introduces the technique of homologous recombination in bacteria to insert a linear DNA fragment into bacterial artificial chromosomes (BACs). Homologous recombination allows the modification of large DNA molecules, in contrast with conventional restriction endonuclease-based strategies, which cleave large DNAs into numerous fragments and are unlikely to permit the precise targeting afforded by recombination-based approaches. The method uses a phage lambda-derived recombination system (using exo, beta, and gam) as well as other enzymatic activities provided by the host (Escherichia coli). In the method described here, a DNA fragment encoding enhanced cyan fluorescent protein is inserted immediately after the start codon of the gene encoding choline acetyltransferase ("ChAT"), the final enzyme in acetylcholine biosynthesis, using homologous recombination between sequences that are present both on the introduced DNA fragment and in the target BAC. The desired recombination products are identified via positive selection for resistance to kanamycin. In principle, the resulting modified BAC could be used to produce transgenic mice that express this fluorescent protein in cholinergic neurons. The approach described here could be used to insert any DNA fragment.