[Show abstract][Hide abstract] ABSTRACT: To derive a clinical prediction rule that uses bedside clinical variables to predict extubation failure (reintubation within 48 h) after a successful spontaneous breathing trial.
This prospective observational cohort study was performed at the Northwestern Memorial Hospital in Chicago, Illinois, which is a large tertiary-care university hospital. Among 673 consecutive patients who received mechanical ventilation during a 15-month period, 122 were ventilated for at least 2 days and did not undergo withdrawal of support or tracheostomy. These patients were followed after extubation to identify those who were reintubated within 48 h (extubation failure). We used logistic regression analysis to identify variables that predict reintubation, and we used bootstrap resampling to internally validate the predictors and adjust for overoptimism.
Sixteen (13%) of the 122 patients required reintubation within 48 h. Three clinical variables predicted reintubation: moderate to copious endotracheal secretions (p = 0.001), Glasgow Coma Scale score < or =10 (p = 0.004), and hypercapnia (P(aCO(2)) > or = 44 mm Hg) during the spontaneous breathing trial (p = 0.001). Using logistic regression and bootstrap resampling to adjust for overfitting, we derived a clinical prediction rule that combined those 3 clinical variables (area under the receiver operating characteristic curve 0.87, 95% confidence interval 0.74-0.94).
With our clinical prediction rule that incorporates an assessment of mental status, endotracheal secretions, and pre-extubation P(aCO(2)), clinicians can predict who will fail extubation despite a successful spontaneous breathing trial.
[Show abstract][Hide abstract] ABSTRACT: To improve antimicrobial use in patients receiving long-term care (LTC).
Prospective, quasi-experimental before-after assessment of the effects of physician education and guideline implementation.
Public LTC and acute care hospital.
Twenty salaried internists who provided most of the medical care to LTC patients.
National guidelines, hospital resistance data, and physician feedback were incorporated into a series of four teaching sessions presented over 18 months and into booklets detailing institutional guidelines on the optimal management of common LTC infection syndromes.
One hundred randomly selected LTC patients treated with antimicrobials were reviewed before these interventions were implemented and 100 after, and measures of the quality of care were compared. The effect of the interventions on antimicrobial days and starts were also assessed using interrupted time series analysis.
Charted clinical abnormalities met guideline diagnostic criteria (62% vs 38%, P=.006), and initial therapy agreed with guideline recommendations (39% vs 11%, P<.001), more often in the post- than in the preintervention cohort. Mean census-adjusted monthly LTC antimicrobial days fell 29.7%, and antimicrobial starts fell 25.9% during the intervention period; both decreases were sustained during the 2-year postintervention period.
The teaching and guideline intervention improved the quality and reduced the quantity of antimicrobial use in LTC patients.
No preview · Article · Aug 2007 · Journal of the American Geriatrics Society
[Show abstract][Hide abstract] ABSTRACT: Patients with obesity hypoventilation syndrome (OHS) have a lower quality of life, more healthcare expenses, a greater risk of pulmonary hypertension, and a higher mortality compared to eucapnic patients with obstructive sleep apnea (OSA). Despite significant morbidity and mortality associated with OHS, it is often unrecognized and treatment is frequently delayed. The objective of this observational study was to determine the prevalence of OHS in patients with OSA seen at the sleep disorders clinic of a large public urban hospital serving predominantly minority population and to identify clinical--not mechanistic--predictors that should prompt clinicians to measure arterial blood gases. In the first stage, we randomly selected 180 patients referred to our sleep disorders clinic between 2000 and 2004 for suspicion of OSA. From this retrospective random sample we calculated the prevalence of OHS in patients with OSA and identified independent clinical predictors using logistic regression. In the second stage, we prospectively validated these predictors in a sample of 410 consecutive patients referred to the sleep disorders clinic for suspicion of OSA between 2005 and 2006. The prevalence of OHS in patients with OSA was 30% in the retrospective random sample and 20% in the prospective sample. Three variables independently predicted OHS in both samples: serum bicarbonate level (p < 0.001), apnea-hypopnea index (p = 0.006), and lowest oxygen saturation during sleep (p < 0.001). Due to the serious morbidity associated with OHS, we selected a highly sensitive threshold of serum bicarbonate level. A threshold of 27 mEq/l had a sensitivity of 92% and a specificity of 50%. Only 3% of patients with a serum bicarbonate level <27 mEq/l had hypercapnia compared to 50% with a serum bicarbonate > or =27 mEq/l. In conclusion, OHS is common in severe OSA. A normal serum bicarbonate level excludes hypercapnia and an elevated serum bicarbonate level should prompt clinicians to measure arterial blood gases.
Full-text · Article · Jun 2007 · Sleep And Breathing
[Show abstract][Hide abstract] ABSTRACT: To determine if structured teaching of bedside cardiac examination skills improves medical residents' examination technique and their identification of key clinical findings.
Firm-based single-blinded controlled trial.
Inpatient service at a university-affiliated public teaching hospital.
Eighty Internal Medicine residents.
The study assessed 2 intervention groups that received 3-hour bedside teaching sessions during their 4-week rotation using either: (1) a traditional teaching method, "demonstration and practice" (DP) (n=26) or (2) an innovative method, "collaborative discovery" (CD) (n=24). The control group received their usual ward teaching sessions (n=25). The main outcome measures were scores on examination technique and correct identification of key clinical findings on an objective structured clinical examination (OSCE).
All 3 groups had similar scores for both their examination technique and identification of key findings in the preintervention OSCE. After teaching, both intervention groups significantly improved their technical examination skills compared with the control group. The increase was 10% (95% confidence interval [CI] 4% to 17%) for CD versus control and 12% (95% CI 6% to 19%) for DP versus control (both P<.005) equivalent to an additional 3 to 4 examination skills being correctly performed. Improvement in key findings was limited to a 5% (95% CI 2% to 9%) increase for the CD teaching method, CD versus control P=.046, equivalent to the identification of an additional 2 key clinical findings.
Both programs of bedside teaching increase the technical examination skills of residents but improvements in the identification of key clinical findings were modest and only demonstrated with a new method of teaching.
Full-text · Article · Feb 2006 · Journal of General Internal Medicine
[Show abstract][Hide abstract] ABSTRACT: Daytime hypercapnia is common in morbidly obese patients with obstructive sleep apnea and is associated with serious complications. Our objective was to quantify the effect of adherence with positive airway pressure on hypercapnia and hypoxia in these patients.
We performed a retrospective cohort study of 75 patients using a multivariable general linear model analysis to identify variables that predicted changes in PaCO2 and PaO2 after therapy. Bootstrap resampling methods were used to calculate confidence intervals for the effects of significant predictors and to internally validate the predictive models.
The variables that predicted the change in PaCO2 were average daily hours of positive pressure therapy, FEV1 percentage of predicted, and baseline PaCO2 (model R(2) = 0.70). The PaCO2 dropped 1.84 mm Hg per hour of adherence and plateaued at 7 hours of average daily use. The PaO2 improved by approximately 3 mm Hg per hour of adherence and plateaued after 4.5 hours of therapy (model R2 = 0.48). Patients who used therapy for more than 4.5 hours per day experienced significant improvements in PaCO2 and PaO2 compared with less-adherent patients (APaCO2 7.7+/-5 vs 2.4+/-4 mm Hg, p < .001; delta PaO2 9.2+/-11 vs 1.8+/-9 mm Hg, p < .001). For adherent patients, the need for daytime home oxygen therapy decreased from 30% to 6% (p = .02).
In hypercapnic patients with obstructive sleep apnea, adherence with positive airway pressure is an important modifiable predictor of improvements in PaCO2 and PaO2, and its benefit plateaus between 5 and 7 hours of daily therapy.
Full-text · Article · Jan 2006 · Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine
[Show abstract][Hide abstract] ABSTRACT: The effectiveness of an infectious diseases (ID) consultation is dependent on adherence to the recommendations. To delineate the factors that affect adherence, we conducted a prospective cohort study of 465 consultations at 2 academic institutions in which we evaluated the consultation process, patient and consultant characteristics, types of recommendations, and compliance with recommendations. The overall compliance rate was 80%, with 85% adherence to crucial recommendations. Multivariate analysis revealed that adherence to ID recommendations was higher when the recommendations were therapeutic instead of diagnostic, when they related to a specific clinical question, when recommendations were deemed crucial by the ID service, if the primary service was medicine, and if the consultation note was legible and organized. Whether modification of consultant practice will lead to improved recommendation compliance and patient outcomes warrants further study.
Full-text · Article · Jun 2004 · Clinical Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Most observational studies indicate that hormone replacement therapy (HRT) protects women from cardiovascular disease. Two recent randomized trials, however, showed no reduction in coronary events with HRT in postmenopausal women. A randomized study evaluating subclinical atherosclerosis showed a beneficial effect of estrogen. In the current study we evaluated the association between HRT and coronary artery atherosclerosis, as quantified by coronary artery calcium score. Current users of HRT were significantly more likely to have a coronary artery calcium score less than 100 and were less likely to have a score greater than 400 than non-HRT users. After adjustment for cardiac risk factors, current use of HRT was associated with a significant reduction of coronary artery calcium score (-28; 95% confidence interval, -48 to -10). The average age of users was 59 yr, the mean duration of use was 9 yr, and the duration of HRT use was significantly associated with a reduction in coronary artery calcium. These results suggest that HRT suppresses atherosclerosis in the coronary arteries. The failure to modify the cardiovascular event rate in clinical trials could result from the adverse effect of HRT on complicated lesions. Additional mechanistic studies may help identify therapeutic strategies that could maximize a potential benefit of HRT on early atherogenesis while minimizing adverse proinflammatory and procoagulant effects on complicated plaque lesions.
Preview · Article · Jan 2004 · Journal of Clinical Endocrinology & Metabolism
[Show abstract][Hide abstract] ABSTRACT: The value of azithromycin for treatment of acute bronchitis is unknown, even though this drug is commonly prescribed. We have investigated this question in a randomised, double-blind, controlled trial.
Adults diagnosed with acute bronchitis, without evidence of underlying lung disease, were randomly assigned azithromycin (n=112) or vitamin C (n=108) for 5 days (total dose for each 1.5 g). All individuals were also given liquid dextromethorphan and albuterol inhaler with a spacer. The primary outcome was improvement in health-related quality of life at 7 days; an important difference was defined as 0.5 or greater. Analysis was by intention to treat.
The study was stopped by the data-monitoring and safety committee when 220 patients had been recruited. On day 7, the adjusted difference in health-related quality of life was small and not significant (difference 0.03 [95% CI -0.20 to 0.26], p=0.8). 86 (89%) of 97 patients in the azithromycin group and 82 (89%) of 92 in the vitamin C group had returned to their usual activities by day 7 (difference 0.5% [-10% to 9%], p>0.9). There were no differences in the frequency of adverse effects; three patients in the vitamin C group discontinued the study medicine because of perceived adverse effects, compared with none in the azithromycin group. Most patients (81%) reported benefit from the albuterol inhaler.
Azithromycin is no better than low-dose vitamin C for acute bronchitis. Further studies are needed to identify the best treatment for this disorder.
[Show abstract][Hide abstract] ABSTRACT: Little is known about physicians' triage decisions for patients with chest pain in the emergency department. We sought to understand better the variability and accuracy of physicians' triage decisions.
We used 20 simulated cases to compare triage decisions by 147 physicians (46 emergency medicine, 87 internal medicine, and 14 cardiology physicians) with triage decisions recommended by a previously validated prediction rule. We calculated triage sensitivity and specificity using the prediction rule to estimate the likelihood that each of the simulated patients would suffer a major complication. Triage sensitivity was defined as the proportion of all patients expected to have major complications who were triaged to the coronary care or inpatient telemetry unit.
Triage specificity was defined as the proportion of all patients without complications who were triaged to sites other than the coronary care or inpatient telemetry unit.Physicians' triage decisions were less sensitive (85% vs. 96%, P <0.001) and less specific (38% vs. 41%, P = 0.02) than decisions recommended by the prediction rule. Physicians overestimated patients' risk of complications and triaged more patients to inpatient monitored beds. Despite their preference for inpatient monitored beds, physicians' decisions would have resulted in four times as many major complications in patients who were not triaged to inpatient monitored beds, compared with decisions recommended by the prediction rule (2.4% vs. 0.6%, P <0.001). Although physicians' decisions were best explained by their provisional diagnoses, interphysician agreement about triage decisions (kappa = 0.34) and diagnosis (kappa = 0.31) was only fair.
In simulated cases, physicians' triage decisions varied widely and their predictions of patient outcomes differed markedly from that of the validated prediction rule, suggesting that use of the prediction rule in the emergency department could improve physicians' decisions and patients' outcomes.
Full-text · Article · Mar 2002 · The American Journal of Medicine