A systematic review of the cost-effectiveness of noncardiac transitional care units.

OBJECTIVE: To critically appraise and summarize the studies examining the cost-effectiveness of noncardiac transitional care units (TCUs). DATA SOURCES: We conducted a computerized literature search using MEDLINE, and Current Contents from January 1, 1986 to December 31, 1995 and HealthSTAR from January 1, 1989 to December 31, 1995 with the key words intermediate care unit, respiratory care unit, and step-down unit. Bibliographies of all selected articles and review articles were examined. Personal files were also reviewed. STUDY SELECTION: (1) POPULATION: patients in a noncardiac TCU of an acute-care institution; (2) intervention: addition of a noncardiac TCU to the institution; and (3) outcomes: patient outcome-survival and associated costs. DATA EXTRACTION: The necessary data were abstracted and study validity was evaluated by two independent reviewers using a modification of previously published criteria. DATA SYNTHESIS: The studies were summarized qualitatively; upon inspection, they were too heterogeneous to allow quantitative analysis. While the studies all claimed that their TCUs were cost-effective, the economic evaluation designs were flawed to such an extent that the validity of the conclusions is suspect. CONCLUSIONS: To date, the evidence in the literature is insufficient to determine under which circumstances, if any, TCUs are a cost-effective alternative technology to the traditional institution with only ICU and general ward beds.

Does implementing pulse oximetry in a critical care unit result in substantial arterial blood gas savings?

OBJECTIVES: To examine the impact of pulse oximetry on the use of arterial blood gas and other laboratory determinations and to examine predictors of the use of arterial blood gas measurements. DESIGN: Before (preoximetry)/after (postoximetry) study. SETTING: Thirty-bed multidisciplinary critical care unit. PATIENTS: Consecutive admissions of 300 patients (150 before and 150 after oximetry). MEASUREMENTS: For each patient examined, the number of arterial blood gas determinations, serum electrolyte levels, complete blood chemistries, arterial lactate levels, and creatinine samples were recorded for the initial 9 days of the stay in the critical care unit. These data were stratified by nursing shift (day vs night) and by the source of the admission (medical vs surgical). Other information collected included demographic variables, the severity of illness, the length of stay in the critical care unit, and various ventilatory parameters. RESULTS: Introducing pulse oximetry was associated with a marginal (10.3 percent; p < 0.025) reduction in the use of arterial blood gas determinations. This decrease was accounted for by changes occurring on the night shift and in the surgical patient. These findings were also observed for serum electrolyte determinations. No significant differences in the use of arterial blood gas measurements were found for medical patients. No significant differences were found in the use of arterial lactate levels, complete blood chemistries, or creatinine determinations. Significant predictors of arterial blood gas determinations included the number of days intubated, the number of ventilator orders, the number of days on an inspired oxygen content (FIO2) greater than 50 percent, and the acute physiology and chronic health evaluation II (APACHE II) score. CONCLUSIONS: The implementation of pulse oximetry in this manner gives an idea how effective the technology will be in reducing the use of arterial blood gas determinations without guidelines for the use of pulse oximetry. As only a marginal decrease was observed in the total population of medical and surgical patients, and only on the night shift, formal and standardized guidelines for the most efficient use of pulse oximetry should be considered. If these were considered, pulse oximetry may indeed make a significant contribution to improving the efficiency of care services.

Assessing the efficiency of the admission process to a critical care unit: does the literature allow the use of benchmarking?

OBJECTIVES: To determine the ability of the current literature to supply appropriate data for benchmarking admission practice to a multidisciplinary critical care unit. DESIGN: Retrospective review of data collected prospectively on a cohort of 614 patients and a systematic review of the literature. SETTING: A 30-bed multidisciplinary critical care unit at a university teaching hospital. PATIENTS: Consecutive admissions to the critical care unit over a 6-month period. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: For each patient, demographic data and admitting diagnosis were recorded on admission. Information necessary to calculate the Acute Physiology and Chronic Health Evaluation II and Therapeutic Intervention Scoring System (TISS) scores were collected daily. TISS variables were categorized as "active" or "non-active" treatment variables. Patients were then identified on a daily basis as receiving or not receiving active treatment. A review of the literature, using MEDLINE and the search term "Therapeutic Intervention Scoring Index" (as a textword), was conducted to identify studies that had similarly divided their patients. Using the method of benchmarking, the proportion of patients admitted who received active treatment during their stay in the critical care units was compared between the index critical care unit and those in the literature. A greater proportion of the patients admitted to our unit received active treatment (97.7%) when compared to other studies in the literature (20-66%). However, a number of potential confounding factors were present, such as the availability of intermediate care units, overnight recovery room ventilation, and critical care bed availability between the index critical care unit and those described in the literature. CONCLUSIONS: The current literature does not provide adequate data on critical care unit admission practices to allow useful application of the method of benchmarking. There is a need for publicly accessible large databases to allow individual critical care units to determine their level of efficiency when compared to similar institutions.

Ventilatory care in a selection of Ontario hospitals: bigger is not necessarily better! Critical Care Research Network (CCR-Net).

OBJECTIVE: To determine whether there is variability in the structure and process of ventilatory care in intensive care units (ICUs) of the hospitals of Southwestern Ontario. DESIGN: Self-administered questionnaire-based survey. SETTING: ICUs of selected community and teaching hospitals of Southwestern Ontario. PARTICIPANTS: Head of respiratory therapy service of respective hospitals; in those hospitals without respiratory therapists, the ICU nurse manager. INTERVENTION: Self-administered questionnaire. OUTCOME MEASURE(S): The availability of different models of ventilators and respiratory therapist and physician coverage were assessed. In addition, the use of clinical practice guidelines, respiratory therapists, and the nursing role in ventilatory care were determined. RESULTS: In general, the structure of ventilatory care, including availability of different modes of ventilation, and coverage by respiratory therapists and physicians was more comprehensive in larger hospitals. However, the availability of some modes of ventilation varied more than expected among hospitals of comparable size. Similarly, variability in the process of ventilatory care, defined by the availability of clinical practice guidelines and the roles of respiratory therapists varied both within and among hospitals of different size. CONCLUSIONS: The structure and process of ventilatory care in this sample of Southwestern Ontario ICUs was found to be variable. Not all this variability could be accounted for by hospital size, suggesting a potential for improvement in overall ventilatory care. Further study is required before any specific recommendations can be considered.

Hyperdynamic sepsis depresses circulatory compensation to normovolemic anemia in conscious rats.

This study was designed to determine whether sepsis modifies the ability to preserve vital organ O2 delivery (QO2) across a clinically relevant range of hematocrits. Ninety rats were randomly allocated to cecal ligation and perforation (CLP) or a sham (Sham) procedure. With the use of rat plasma, rat whole blood, or packed rat red blood cells, respectively, randomization into three different hematocrit subgroups followed: low (21-28%), middle (33-40%), and high (45-52%). Organ blood flow values (Q) were measured by the radioactive microsphere technique, and organ QO2 values were calculated. Twenty-four hours after laparotomy, the hematocrit grouping had not modified the interorgan distribution of Q or QO2 in either the CLP or Sham rats. To characterize overall metabolic O2 reserve, rats were then exposed to hypoxia (inspired O2 fraction, 0.08) for 20 min. Whereas cardiac output increased significantly during hypoxia in all experimental groups, myocardial QO2 failed to increase in the low hematocrit Sham subgroup and fell significantly in both the middle- and low-hematocrit CLP subgroups. There was also a lesser redistribution of QO2 away from the small intestine in the low-hematocrit compared with the high-hematocrit CLP subgroup. We conclude that myocardial QO2 is more effectively maintained in septic hypoxic rats if the hematocrit is maintained at levels >45%.

Circulatory sequelae of administering CPAP in hyperdynamic sepsis are time dependent.

Evidence questions the circulation's ability to acutely compensate for abrupt changes in O2 delivery (Qo2). Because both sepsis and continuous positive airway pressure (CPAP) may alter the metabolic regulation of tissue oxygenation, we designed an experiment to determine the interaction, if any, between sepsis and time on circulatory homeostasis after the application of CPAP. Twenty-four sheep were randomized to cecal ligation and perforation (CLP) or sham procedure (Sham) and then rerandomized to receive either CPAP (10 mmHg) or no CPAP (No CPAP; CLP/CPAP, n = 8; CLP/No CPAP, n = 8; Sham/CPAP, n = 4; Sham/No CPAP, n = 4). Forty-eight hours later, CLP animals demonstrated an elevated cardiac index (+63%), systemic Qo2 (+49%), and systemic O2 uptake (+28%). Organ blood flow, measured with radiolabeled microspheres, was augmented to the heart and depressed in organs comprising the splanchnic circulation. Compared with the CLP/No CPAP group and both Sham groups, myocardial Qo2 in the CLP/ CPAP group was significantly elevated when measured both 2 and 8 h after CPAP. These changes were unrelated to differences in mean heart work between the study groups. Simultaneously, QO2 to all of the small gut, large gut, pancreas, and kidney in the CLP/CPAP group was elevated during the 2-h study yet reverted to levels not different from baseline by the 8-h study. These data demonstrate 1) a unique sepsis x time interaction with the use of 10 mmHg of CPAP, particularly in the "nonvital" circulations, and 2) CPAP effects on the septic coronary circulation, which were unexplained by changes in external determinants of myocardial O2 need.

A Bayesian statistical method for the detection and quantification of rotational diffusion anisotropy from NMR relaxation data.

It has recently become more widely appreciated that the presence of rotational diffusional anisotropy in proteins and other macromolecules can have a significant affect on the interpretation of NMR relaxation data in terms of molecular motion. In this paper, we show how commonly used NMR relaxation data (R(1), R(2), and NOE) obtained at two spectrometer frequencies can be analyzed using a Bayesian statistical approach to reliably detect and quantify the degree of rotational diffusion anisotropy. Our approach differs from previous methods in that it does not make assumptions concerning the internal motions experienced by the residues which are used to quantify the diffusion anisotropy, but rather averages the results over all internal motions consistent with the data. We demonstrate our method using synthetic data corresponding to isotropic, axially symmetric anisotropic, and fully asymmetric anisotropic rotational diffusion, as well as experimental NMR data. We compare the Bayesian statistical approach with a widely used method for extracting tumbling parameters using both synthetic and experimental data. While it can be difficult to separate the effects of chemical exchange from rotational anisotropy using this "standard" method, these effects are readily separated using Bayesian statistics. In addition, we find that the Bayesian statistical approach requires considerably less CPU time than an equivalent standard analysis.

The origin of evidence.

Forensic science is an applied science based on the laws of physics and chemistry. Over time, a set of fundamental concepts has developed that apply specifically to a forensic analysis. Traditionally, five concepts have been articulated: transfer, identification, individualization, association between source and target, and reconstruction. We suggest that an additional sixth concept, the idea that matter must divide before it can be transferred, is necessary to complete the paradigm. Divisible matter is particularly useful in describing physical match evidence. Additionally, we propose a paradigm that logically divides into scientific principles that govern the generation of evidence, and processes that pertain to the recognition, analysis, and interpretation of evidence. The principles of divisible matter and transfer pertain to the generation of evidence before and during the crime event; the processes of identification, classification or individualization, association, and reconstruction describe the practice of forensic science starting with the recognition of an item as evidence.

Comparison of placental findings in type 1 and type 2 diabetic pregnancies.

INTRODUCTION: The aim of this study is to compare placental pathology and related clinical parameters between gravidas with type 1 and type 2 pregestational diabetes. METHODS: This is a retrospective cohort study of women with singleton gestations and pregestational diabetes who delivered at Women and Infants Hospital from 2003 to 2011. Pathology reports, maternal and neonatal outcomes were extracted and compared between the two groups. RESULTS: In our cohort, 293 pregnancies were studied, including 117 with type 1 diabetes and 176 with type 2 diabetes. Women with type 1 diabetes had worse glycemic control during pregnancy, as characterized by higher HbA1c values and average fasting and postprandial blood sugars. More infants from the type 1 group were admitted to Neonatal ICU. Pregestational diabetes led to small for gestational age (SGA) placentas in nearly 20% pregnancies and large for gestational age (LGA) placentas in 30% of cases. Both groups shared similar incidences of preeclampsia and significant placental pathology related to uteroplacental (maternal) and fetal circulatory disorders; however, maternal decidual vasculopathy and placentas with insufficiency (fetal-to-placental weight ratio < 10th %tile) were more commonly found in placentas from women with type 2 diabetes. DISCUSSION: Both types of pregestational diabetes have significant impact on placental growth and development. The comparison between the two groups suggests different pathogenetic mechanisms and may be helpful for better management of diabetic pregnancy.