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Biomedical subjects

Steve G Peters

Publications and source records attributed to Steve G Peters.

At least 19 recordsLinked to original sources

Continuous bronchodilator therapy.

Inhaled bronchodilators are first-line treatment for acute exacerbations of asthma. Continuous bronchodilator administration is a novel option for the treatment of bronchospasm, which may be more effective than intermittent therapy for patients with severe airflow obstruction. For 2007, coding and billing changes for this modality become effective. This article reviews clinical aspects and outpatient practice management of continuous bronchodilator therapy.

Administration, Inhalation↗

Bronchoscopy in ventilator-associated pneumonia: agreement of calibrated loop and serial dilution.

RATIONALE: Although the serial dilution technique for quantitative culture of bronchoalveolar fluid is considered to be the gold standard for the diagnosis of ventilator-associated pneumonia, it is more labor intensive than the calibrated loop technique. OBJECTIVE: We sought to determine the agreement between the calibrated loop and serial dilution techniques in the diagnosis of ventilator-associated pneumonia. METHODS: We prospectively measured bacterial colony counts by the serial dilution and calibrated loop techniques in 121 bronchoalveolar lavage samples of 104 patients with suspected ventilator-associated pneumonia. MEASUREMENTS AND MAIN RESULTS: At the time of bronchoscopy, patients had received mechanical ventilation for a median of 8 d. Patients were receiving antibiotics when 90 of the 121 (74.4%) bronchoalveolar samples were obtained. The colony counts of 13 bacterial isolates were too numerous to count by the calibrated loop technique; by serial dilution technique, their counts ranged from 4.70 to 6.74 log10 cfu/ml. Fifty other bacteria had paired colony counts measured by each of the two techniques: the bias (95% confidence interval) between the two techniques was -0.380 (-0.665 to -0.095) log10 cfu/ml, with precision of 1.002 log10 cfu/ml and 95% limits of agreement of -2.344 to 1.584 log10 cfu/ml. Using the threshold of 4 log10 cfu/ml as a criterion for the diagnosis of ventilator-associated pneumonia, there was discordance only for one bacterial organism between the two techniques. CONCLUSIONS: The calibrated loop technique can be used for the diagnosis of ventilator-associated pneumonia using bronchoalveolar lavage fluid.

Anti-Bacterial Agents↗

Major complications following hematopoietic stem cell transplantation.

Tens of thousands of patients undergo hematopoietic stem cell transplantation (HSCT) annually, 15 to 40% of whom are admitted to the intensive care unit. Pulmonary complications are the most life threatening conditions that develop in HSCT recipients. Both infectious and noninfectious complications occur more frequently in allogeneic HSCT. The management of HSCT recipients requires knowledge of their immune status, appropriate diagnostic evaluation, and early treatment. During the pre-engraftment phase (0 to 30 days after transplant), the most prevalent pathogens causing infection are bacteria and Candida species and, if the neutropenia persists, Aspergillus species. The early post-engraftment phase (30 to 100 days) is characterized by cytomegalovirus (CMV), Pneumocystis jiroveci, and Aspergillus infections. During the late posttransplant phase (> 100 days), allogeneic HSCT recipients are at risk for CMV, community-acquired respiratory virus, and encapsulated bacterial infections. Antigen and polymerase chain reaction assays are important for the diagnosis of CMV and Aspergillus infections. Diffuse alveolar hemorrhage (DAH) and peri-engraftment respiratory distress syndrome occur in both allogeneic and autologous HSCT recipients, usually during the first 30 days. Bronchiolitis obliterans occurs exclusively in allogeneic HSCT recipients with graft versus host disease. Idiopathic pneumonia syndrome occurs at any time following transplant. Bronchoscopy is usually helpful for the diagnosis of the infectious pulmonary complications and DAH.

Aspergillosis↗

Evidence-based red cell transfusion in the critically ill: quality improvement using computerized physician order entry.

OBJECTIVE: The implementation of evidence-based practice poses a significant challenge in the intensive care unit. In this quality improvement intervention we assessed the effect of an institutional protocol and computerized decision support for red cell transfusion in the critically ill. DESIGN: We compared processes of care and outcomes during the two 3-month periods before and after the introduction of a multidisciplinary quality improvement intervention. SETTING: Multidisciplinary intensive care units--medical, surgical, and mixed--in a tertiary academic center. PATIENTS: Consecutive critically ill patients with anemia (hemoglobin of <10 g/dL). INTERVENTION: Using the computerized provider order entry, we developed an evidence-based decision algorithm for red cell transfusion in adult intensive care units. MEASUREMENTS AND MAIN RESULTS: We collected information on demographics, diagnosis, severity of illness, transfusion complications, and laboratory values. The main outcome measures were number of transfusions, proportion of patients who were transfused outside evidence-based indications, transfusion complications, and adjusted hospital mortality. The mean number of red cell transfusions per intensive care unit admission decreased from 1.08 +/- 2.3 units before to 0.86 +/- 2.3 units after the protocol (p<.001). We observed a marked decrease in the percentage of patients receiving inappropriate transfusions (17.7% vs. 4.5%, p< .001). The rate of transfusion complications was also lower in the period after the protocol (6.1% vs. 2.7%, p = .015). In the multivariate analysis, protocol introduction was associated with decreased likelihood of red cell transfusion (odds ratio, 0.43; 95% confidence interval, 0.30 to 0.62). Adjusted hospital mortality did not differ before and after protocol implementation (odds ratio, 1.12; 95% confidence interval, 0.69 to 1.8). CONCLUSIONS: The implementation of an institutional protocol and decision support through a computerized provider order entry effectively decreased inappropriate red cell transfusions.

Algorithms↗

The influence of missing components of the Acute Physiology Score of APACHE III on the measurement of ICU performance.

OBJECTIVE: To determine the impact of missing Acute Physiology Score (APS) values on risk-adjusted mortality. DESIGN: Retrospective review of prospectively collected Acute Physiology and Chronic Health Evaluation (APACHE) III database. SETTING: The intensive care units (ICUs) of an academic medical center. PATIENTS: 38,411 patients admitted to ICU between October 1994 and December 2003. MEASUREMENTS AND RESULTS: Data were collected on ICU type, missing first ICU day APS values, predicted and observed hospital mortality, standardized mortality ratio (SMR), 95% confidence interval (CI), odds ratio (OR). The overall observed and predicted hospital mortality rates were 8.7% and 10.8%, respectively, with SMR of 0.806 (95% CI 0.779-0.834). Complete data were available in 829 (2.2%). Vital signs were missing in almost none and serum albumin and bilirubin in over 80% of the patients. The number of missing variables was higher in less sick and surgical ICU patients. Logistic regression analysis showed that the risk of dying in the hospital was significantly associated with the number of missing APS variables (OR 1.058, 95% CI 1.027-1.090) when adjusted for the severity of illness. The risk of death was also associated with the type of missing variables. CONCLUSIONS: Since missing APS values may lead to underestimation of the predicted mortality rates, the number and type of missing variables should be taken into consideration when assessing the performance of an ICU. Unless data collection is standardized, future prognostic models should use variables that are routinely measured in most critically ill patients without sacrificing statistical precision.

APACHE↗

Acute lung injury after hematopoietic stem cell transplantation.

Hematopoietic stem cell transplantation (HSCT) has emerged as a common therapeutic option for a variety of life-threatening disorders, especially hematologic malignancies. Pulmonary complications are reported in 30% to 60% of all recipients and represent a major cause of mortality. A major proportion of these complications are the direct result of infection. This article addresses early, noninfectious causes of acute lung injury in the HSCT recipient.

Hematologic Neoplasms↗

Chronic lung disease after hematopoietic stem cell transplantation.

Tens of thousands of patients undergo hematopoietic stem cell transplantation (HSCT) each year, mainly for hematologic disorders. In addition to the underlying diseases, the chemotherapy and radiation therapy that HSCT recipients receive can result in damage to multiple organ systems. Pulmonary complications develop in 30% to 60% of HSCT recipients. With the widespread use of prophylaxis for certain infections, the spectrum of pulmonary complications after HSCT has shifted from more infectious to noninfectious complications. This article reviews some of the noninfectious, chronic pulmonary complications.

Chronic Disease↗

Sepsis and myocardial depression in a young woman.

Severe sepsis may be associated with depression of myocardial function, attributed to various inflammatory mediators. Myocardial dysfunction in sepsis is characterized by biventricular failure and complicates usual therapy with high-volume fluid resuscitation and vasopressors. However, in patients who survive septic shock, myocardial dysfunction can improve rapidly. We describe a young woman with septic shock due to Streptococcus pneumoniae, complicated by severe but reversible biventricular dysfunction.

Adult↗

Pulmonary complications in adult blood and marrow transplant recipients: autopsy findings.

STUDY OBJECTIVE: To describe the pulmonary findings at autopsy of blood and bone marrow transplant (BMT) recipients. DESIGN: Retrospective. SETTING: An academic medical center. PATIENTS: Seventy-one deceased adult BMT recipients. INTERVENTIONS: None. MEASUREMENTS: Antemortem and postmortem pulmonary findings. RESULTS: The transplants were allogeneic in 39 patients (55%), with a peripheral stem cell source in 43 patients (61%). Death occurred at a median of 1.30 months after transplant. Ninety-six pulmonary complications were noted in 63 patients (89%): 27 infectious (bacterial bronchopneumonia, n = 13; pulmonary aspergillosis, n = 11; cytomegalovirus pneumonia, n = 2; and Candida bronchopneumonia, n = 1) and 69 noninfectious (diffuse alveolar damage, n = 35; diffuse alveolar hemorrhage [DAH], n = 10; amyloidosis, n = 9; pulmonary embolism, n = 5; lymphoma/leukemia, n = 4; bronchiolitis obliterans, n = 2; bronchiolitis obliterans organizing pneumonia, n = 1; pulmonary alveolar proteinosis, n = 1; aspiration pneumonia, n = 1; and acute and organizing pneumonia, n = 1). Twenty-seven of the 96 complications (28%) were diagnosed antemortem. Infectious complications were more likely to be diagnosed antemortem compared to noninfectious complications (48% vs 20%, p = 0.006). Six of the 13 patients with bronchopneumonia (46%), 5 of the 11 patients with pulmonary aspergillosis (45%), and 7 of the 8 patients with DAH (88%) at autopsy were not receiving treatment for these conditions at the time of death. Ten patients being treated for suspected pulmonary aspergillosis, 7 patients treated for suspected pulmonary cytomegalovirus infection, 22 patients treated for suspected bacterial pneumonia, 2 patients treated for suspected Pneumocystis carinii pneumonia, and 12 patients treated for DAH at the time of death had no evidence of these conditions at autopsy. The most common immediate cause of death was respiratory failure (n = 37, 52%). CONCLUSIONS: Pulmonary complications, the majority not diagnosed antemortem, are the most common cause of death in BMT recipients. As the result of underdiagnosis, BMT recipients may not receive appropriate therapy for potentially treatable pulmonary complications.

Adult↗

Evaluating the performance of an institution using an intensive care unit benchmark.

OBJECTIVES: To describe the performances of selected intensive care units (ICUs) in a single institution using the Acute Physiology and Chronic Health Evaluation (APACHE) III benchmark and to propose interventions that may improve performance. PATIENTS AND METHODS: In this retrospective study, we analyzed APACHE III data from critically ill patients admitted to ICUs at the Mayo Clinic in Rochester, Minn, between October 1994 and December 2003. We retrieved ICU performance measures based on first ICU day APACHE III values. Standardized ratios were defined as ratios of measured to predicted values. The primary performance measure was the standardized mortality ratio, and secondary performance measures were length of stay (LOS) ratios, low-risk monitor ICU admission rates, and ICU readmission rates. We calculated 95% confidence intervals (CIs) for each performance, graded as good, average, or poor. RESULTS: Among 46,381 patients admitted during the study period, 57.5% were in surgical ICUs, 24.8% in a medical ICU, and 17.7% in a surgical-medical ICU. Low-risk monitoring accounted for 37.2% of admissions. Hospital standardized mortality ratios (95% CI) were 0.95 (0.90-0.99), 0.86 (0.81-0.91), and 0.70 (0.66-0.74) for medical, multispecialty, and surgical ICUs, respectively. Hospital LOS ratios (95% CI) were 0.83 (0.81-0.85), 0.91 (0.88-0.93), and 0.99 (0.97-1.00) for medical, multispecialty, and surgical ICUs, respectively. The ICU readmission rate for each ICU was higher than the 6.7% reported in the medical literature. Performances were good in mortality, average to good in LOS, average in low-risk admission, and poor in ICU readmission. CONCLUSIONS: A national benchmarking database can highlight the strengths and weaknesses of ICUs. The performances of ICUs in a single institution may differ; therefore, the performance of each unit should be evaluated individually.

APACHE↗

Mortality rate and length of stay of patients admitted to the intensive care unit in July.

OBJECTIVE: At the beginning of each academic year in July, inexperienced residents and fellows begin to care for patients. This inexperience can lead to poor patient outcome, especially in patients admitted to the intensive care unit (ICU). The objective of this study was to determine the impact of July ICU admission on patient outcome. DESIGN: Retrospective, cohort study. SETTING: Academic, tertiary medical center. PATIENTS: Patients admitted to the ICU from October 1994 through September 2002. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographics, Acute Physiology and Chronic Health Evaluation (APACHE) III score and predicted mortality, admission source, admission date, intensity of treatment, ICU length of stay (LOS), and hospital mortality of 29,084 patients were obtained. The actual and predicted weighted ICU LOS and their ratio were calculated. Logistic regression analysis was used to compare the hospital mortality rate of patients admitted to the ICU in July with those admitted during the rest of the year, with adjustment for potentially confounding variables. The patients' mean age was 62.3 +/- 17.6 yrs; 57.3% were male and 95.5% white. Both the customized predicted and observed hospital mortality rates of the entire cohort were 8.2%. The majority (76.7%) of the patients were discharged home, and 15.1% were discharged to other facilities. When adjusted for potentially confounding variables, ICU admission in July was not associated with higher hospital mortality rate compared with any other month. There were no significant differences in the discharge location of patients between July and any one of the other months. There were no statistically significant differences in the weighted ICU LOS ratio between July and any of the other months. CONCLUSIONS: ICU admission in July is not associated with increased hospital mortality rate or ICU length of stay.

APACHE↗

The hospital mortality of patients admitted to the ICU on weekends.

STUDY OBJECTIVES: Previous studies have suggested that patients are more likely to die in the hospital if they are admitted on a weekend than on a weekday. This study was conducted to determine whether weekend admission to the ICU increases the risk of dying in the hospital. DESIGN: Retrospective cohort study. SETTING: ICU of a single tertiary care medical center. PATIENTS: A total of 29,084 patients admitted to medical, surgical, and multispecialty ICUs from October 1994 through September 2002. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The weekend ICU admissions comprised 27.9% of all ICU admissions (8,108 ICU admissions). The overall hospital mortality rate was 8.2% (2,385 deaths). Weekend ICU admission was associated with a higher unadjusted hospital mortality rate than that for weekday ICU admission (11.3% vs 7.0%, respectively; odds ratio [OR], 1.70; 95% confidence interval [CI], 1.55 to 1.85). In multivariable analyses controlling for the factors associated with mortality such as APACHE (acute physiology and chronic health evaluation) III predicted mortality rate, ICU admission source, and intensity of treatment, no statistically significant difference in hospital mortality was found between weekend and weekday admissions in the overall study population (OR, 1.06; 95% CI, 0.95 to 1.17). For weekend ICU admissions, the observed hospital mortality rates of the medical, multispecialty, and surgical ICUs were 15.2%, 17.2%, and 6.4%, respectively, and for weekday ICU admissions the rates were 16.3%, 10.1%, and 3.5%, respectively. Subgroup analyses showed that weekend ICU admission was associated with higher adjusted hospital mortality rates than was weekday ICU admission in the surgical ICU (OR, 1.23; 95% CI, 1.03 to 1.48), but not in the medical or multispecialty ICUs. CONCLUSIONS: The overall adjusted hospital mortality rate of patients admitted to the ICU on a weekend was not higher than that of patients admitted on a weekday. However, weekend ICU admission to the surgical ICU was associated with an increased hospital mortality rate.

APACHE↗

Identifying potentially ineffective care in the sickest critically ill patients on the third ICU day.

OBJECTIVE: To determine if an increase in the third-ICU-day acute physiology score (APS) of the APACHE (acute physiology and chronic health evaluation) III prognostic system can identify potentially ineffective care. DESIGN: Retrospective cohort study. SETTING: Academic medical center. PATIENTS: Adult patients with first-ICU-day predicted mortality rate > or = 80%. MEASUREMENTS: Demographics, ICU admission source, admission type, ICU admission diagnosis, first- and third-ICU-day APSs, APACHE III score, APACHE III-predicted hospital mortality, hospital discharge status, 100-day survival, and ICU and hospital length of stay. RESULTS: A total of 302 patients (age [mean +/- SD], 64.7 +/- 15.8 years; 54.3% male gender) were included in the study. Respiratory failure was the most common reason for ICU admission. Nonoperative admissions accounted for 94.7%. The first- and third-ICU-day APSs were 106.8 +/- 19.8 and 70.5 +/- 29.9, respectively. The first- and third-ICU-day predicted hospital mortality rates were 87.8 +/- 5.3% and 86.5 +/- 14.8%, respectively. The hospital mortality rate was 61.3%, and the 100-day survival rate 28.5%. The third-ICU-day APS was higher than the first-ICU-day APS in 34 patients (11.3%). Only 2 of these 34 patients (6%) survived to hospital discharge, compared to 115 of 268 patients (43%) without an increase in APS (p < 0.0001). Of the two hospital survivors with increased APS, only one patient survived 100 days after hospital discharge. In predicting 100-day mortality, the sensitivity of an increase in the third-ICU-day APS was 15.3% (95% confidence interval, 11.1 to 20.7%), specificity was 98.8% (95% confidence interval, 93.7 to 99.8%), positive predictive value was 97.1% (95% confidence interval, 85.1 to 99.5%), and negative predictive value was 31.7% (95% confidence interval, 26.4 to 37.5%). CONCLUSIONS: A higher APS on the third ICU day, compared to the first ICU day, identifies potentially ineffective care in patients with the first-day predicted hospital mortality rate > or = 80%.

APACHE↗

Increased risk associated with pulmonary artery catheterization in the medical intensive care unit.

PURPOSE: To determine whether the frequency of use of a pulmonary artery catheter (PAC) was declining over a 5-year period in a medical intensive care unit (ICU), and to assess whether mortality was higher in patients in whom a PAC was used on the day of ICU admission compared with matched controls. METHODS: Observational, retrospective, matched-set study using prospectively collected Acute Pysiology, Age and Chronic Health Evaluation (APACHE) III data during a 5-year period, from 1995 to 2000, at a 15-bed medical ICU in an academic referral center. A total of 360 patients, 202 men and 158 women, in whom a PAC was placed on the first ICU day, were compared with 690 controls without a PAC, matched by primary diagnosis group and APACHE III-predicted hospital mortality. RESULTS: A PAC was used during the first day in 7.7% of ICU admissions (yearly range, 5.7% to 9.1%) and did not change significantly during the study period. A total of 187 study patients (27.0%) without a PAC and 132 (36.7%) with a PAC died during their hospital stay. PAC use was a significant risk factor for hospital death from a univariate analysis (odds ratio = 1.5; 95% confidence interval (CI), 1.1-2.1; P =.006). From multivariate analysis, the use of a pulmonary artery catheter was a significant risk factor for hospital death after adjusting for age, date of ICU admission, and predicted hospital mortality (odds ratio = 1.5; 95% CI; 1.1-2.0; P =.016). CONCLUSION: PAC use on the day of admission to a medical ICU was associated with an increased risk for hospital death.

APACHE↗

Hospital mortality rate and length of stay in patients admitted at night to the intensive care unit.

OBJECTIVE: Although admission of patients to a medical ward after 5:00 pm has been associated with increased mortality rate and possibly shorter hospital stay, the association between timing of admission to the intensive care unit and outcome has not been studied. The objective of this study was to determine whether there are any associations between the timing of patient admission to a medical intensive care unit and hospital outcome. DESIGN: A retrospective cohort study that used an Acute Physiology and Chronic Health Evaluation III database containing prospectively collected demographic, clinical, and outcome information for patients. Patients were divided according to the time of admission into daytime (from 7:00 am to 5:00 pm) and nighttime admissions. We further subdivided nighttime admissions into two groups (regular and heavy workload) according to the number of patients who were admitted during the same shift. SETTING: Medical intensive care unit (a 15-bed unit in an academic referral hospital). PATIENTS: 6,034 patients consecutively admitted to our medical intensive care unit over a 5-yr period starting April 10, 1995. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The patients admitted at night had a lower mortality rate (13.9 vs. 17.2%, p < .0001), adjusted for admission source and severity of illness. Their hospital stay was shorter, 11.0 days +/- 13.5 (median 7) vs. 12.7 +/- 14.8 (median 8; p < .0001), as was their intensive care unit stay, 3.5 +/- 4.4 days (median 2) vs. 3.9 +/- 4.7 (median 2; p < .0001), compared with the daytime admission group. The nighttime shifts that admitted three or more patients (heavy workload) had the same mortality rate (13.2%) as those with fewer admissions (14.5%; p = .5961). Hospital and intensive care unit stays were also similar in both workload groups. CONCLUSIONS: Nighttime admission to our intensive care unit is not associated with a higher mortality rate or a longer hospital or intensive care unit stay compared with daytime admission.

APACHE↗