Dean K. Sorenson

A replicable method for blood glucose control in critically Ill patients.

Context:To ensure interpretability and replicability of clinical experiments, methods must be adequately explicit and should elicit the same decision from different clinicians who comply with the study protocol. Objective:The objective of this study was to determine whether clinician compliance with protocol recommendations exceeds 90%. Design:We developed an adequately explicit computerized protocol (eProtocol-insulin) for managing critically ill adult patient blood glucose. We monitored clinician compliance with eProtocol-insulin recommendations in four intensive care units in four hospitals and compared blood glucose distributions with those of a simple clinical guideline at one hospital and a paper-based protocol at another. All protocols and the guideline used intravenous insulin and 80 to 110 mg/dL (4.4–6.1 mmol/L) blood glucose targets. Setting:The setting for this study was four academic hospital intensive care units. Patients:This study included critically ill adults requiring intravenous insulin. Intervention:Intervention used in this study was a bedside computerized protocol for managing blood glucose. Main Outcome Measure:The main outcome measure was clinician compliance with eProtocol-insulin recommendations. Results:The number of patients was 31 to 458 and the number of blood glucose measurements was 2,226 to 19,925 among the four intensive care units. Clinician compliance with eProtocol-insulin recommendations was 91% to 98%. Blood glucose distributions were similar in the four hospitals (generalized linear model p = .18). Compared with the simple guideline, eProtocol-insulin glucose measurements within target increased from 21% to 39%, and mean blood glucose decreased from 142 to 115 mg/dL (generalized linear model p < .001). Compared with the paper-based protocol, eProtocol-insulin glucose measurements within target increased from 28% to 42%, and mean blood glucose decreased from 134 to 116 mg/dL (generalized linear model p = .001). Conclusions:The 91% to 98% clinician compliance indicates eProtocol-insulin is an exportable instrument that can establish a replicable experimental method for clinical trials of blood glucose management in critically ill adults. Control of blood glucose was better with eProtocol-insulin than with a simple clinical guideline or a paper-based protocol.

Multicenter Validation of a Computer-Based Clinical Decision Support Tool for Glucose Control in Adult and Pediatric Intensive Care Units

Introduction: Hyperglycemia during critical illness is common, and intravenous insulin therapy (IIT) to normalize blood glucose improves outcomes in selected populations. Methods differ widely in complexity, insulin dosing approaches, efficacy, and rates of hypoglycemia. We developed a simple bedside-computerized decision support protocol (eProtocol-insulin) that yields promising results in the development center. We examined the effectiveness and safety of this tool in six adult and five pediatric intensive care units (ICUs) in other centers. Methods: We required attending physicians of eligible patients to independently intend to use intravenous insulin to normalize blood glucose. We used eProtocol-insulin for glucose control for a duration determined by the clinical caregivers. Adults had an anticipated length of stay of 3 or more days. In pediatric ICUs, we also required support or intended support with mechanical ventilation for greater than 24 hours or with a vasoactive infusion. We recorded all instances in which eProtocol-insulin instructions were not accepted and all blood glucose values. An independent data safety and monitoring board monitored study results and subject safety. Bedside nurses were selected randomly to complete a paper survey describing their perceptions of quality of care and workload related to eProtocol-insulin use. Results: Clinicians accepted 93% of eProtocol-insulin instructions (11,773/12,645) in 100 adult and 48 pediatric subjects. Forty-eight percent of glucose values were in the target range. Both of these results met a priori-defined efficacy thresholds. Only 0.18% of glucose values were ≤40 mg/dl. This is lower than values reported in prior IIT studies. Although nurses reported eProtocol-insulin required as much work as managing a mechanical ventilator, most nurses felt eProtocol-insulin had a low impact on their ability to complete non-IIT nursing activities. Conclusions: A multicenter validation demonstrated that eProtocol-insulin is a valid, exportable tool that can assist clinicians in achieving control of glucose in critically ill adults and children.

Evaluation of the Model

In the evaluation phase, the expert system is tested by comparing the differential diagnosis at each stage of the patient workup with the expert’s opinion and determining where the knowledge base might be revised to improve performance. This process is carried out first. If the system appears to be overconfident about a particular diagnosis (i.e., assigns a higher probability to that diagnosis than the expert thinks appropriate), suspicion is raised that the false positive rate assigned to some data item already entered for the patient being diagnosed is too low. Another explanation might be that highly associated findings are being treated as independent; i.e., they need to be represented as an “or” group or built into a cluster.

The evolution of eProtocols that enable reproducible clinical research and care methods

Unnecessary variation in clinical care and clinical research reduces our ability to determine what healthcare interventions are effective. Reducing this unnecessary variation could lead to further healthcare quality improvement and more effective clinical research. We have developed and used electronic decision support tools (eProtocols) to reduce unnecessary variation. Our eProtocols have progressed from a locally developed mainframe computer application in one clinical site (LDS Hospital) to web-based applications available in multiple languages and used internationally. We use eProtocol-insulin as an example to illustrate this evolution. We initially developed eProtocol-insulin as a local quality improvement effort to manage stress hyperglycemia in the adult intensive care unit (ICU). We extended eProtocol-insulin use to translate our quality improvement results into usual clinical care at Intermountain Healthcare ICUs. We exported eProtocol-insulin to support research in other US and international institutions, and extended our work to the pediatric ICU. We iteratively refined eProtocol-insulin throughout these transitions, and incorporated new knowledge about managing stress hyperglycemia in the ICU. Based on our experience in the development and clinical use of eProtocols, we outline remaining challenges to eProtocol development, widespread distribution and use, and suggest a process for eProtocol development. Technical and regulatory issues, as well as standardization of protocol development, validation and maintenance, need to be addressed. Resolution of these issues should facilitate general use of eProtocols to improve patient care.

An Electronic Protocol for Translation of Research Results to Clinical Practice: A Preliminary Report

Introduction: We evaluated the feasibility of using an electronic protocol developed for research use (Research-eProtocol-insulin) for blood glucose management in usual intensive care unit clinical practice. Methods: We implemented the rules of Research-eProtocol-insulin in the electronic medical record of the Intermountain Healthcare hospital system (Clinical-eProtocol-insulin) for use in usual clinical practice. We evaluated the performance of Clinical-eProtocol-insulin rules in the intensive care units of seven Intermountain Healthcare hospitals and compared this performance with the performance of Research-eProtocol-insulin at the LDS Hospital Shock/Trauma/Respiratory Intensive Care Unit. Results: Clinician (nurse or physician) compliance with computerized protocol recommendations was 95% (of 21,325 recommendations) with Research-eProtocol-insulin and 92% (of 109,458 recommendations) with Clinical-eProtocol-insulin. The blood glucose distribution in clinical practice (Clinical-eProtocol-insulin) was similar to the research use distribution (Research-eProtocol-insulin); however, the mean values (119 mg/dl vs 113 mg/dl) were statistically different (P = 0.0001). Hypoglycemia rates in the research and practice settings did not differ: the percentage of measurements ≤40 mg/dl (0.11% vs 0.1%, P = 0.65) and the percentage of patients with at least one blood glucose ≤40 mg/dl (4.2% vs 3%, P = 0.23) were not statistically significantly different. Conclusion: Our electronic blood glucose protocol enabled translation of a research decision-support tool (Research-eProtocol-insulin) to usual clinical practice (Clinical-eProtocol-insulin).

A frame-based representation for a bedside ventilator weaning protocol

We describe the use of a frame-based knowledge representation to construct an adequately-explicit bedside clinical decision support application for ventilator weaning. The application consists of a data entry form, a knowledge base, an inference engine, and a patient database. The knowledge base contains database queries, a data dictionary, and decision frames. A frame consists of a title, a list of findings necessary to make a decision or carry out an action, and a logic or mathematical statement to determine its output. Frames for knowledge representation are advantageous because they can be created, visualized, and conceptualized as self-contained entities that correspond to accepted medical constructs. They facilitate knowledge engineering and provide understandable explanations of protocol outputs for clinicians. Our frames are elements of a hierarchical decision process. In addition to running diagnostic and therapeutic logic, frames can run database queries, make changes to the user interface, and modify computer variables.

Corticosteroids stimulate an increase in phospholipase A2 inhibitor in human serum.

A corticosteroid induced increase in a circulating inhibitor of serum phospholipase A2 activity is described. Inhibitor activity was found to be normally present in serum in agreement with the findings of other workers, and this activity was significantly increased by either acute or chronic administration of corticosteroids. The possible relation of this inhibitor to the known inhibitory effects of lipocortin and sphingomyelin on phospholipase A2 activity is briefly discussed.

SV40 RNA: Filter hybridization for rapid isolation and characterization of rare RNAs

Abstract Modifications of the filter hybridization method for the measurement and isolation of simian virus 40 (SV40) RNA from transformed cells are described. The modified method used small (0.02 cm 2 ) nitrocellulose filters with > 30 μg/cm 2 SV40 DNA applied following formaldehyde denaturation. The small volume and high DNA densities allowed hybridization to be completed in 2 h and washing after hybridization to be completed in 6 h. The washing reduced background to 1 × 10 −5 of input radioactivity without using nucleases. The efficiency of hybridization after washing was 40% or greater. These procedures have allowed the quantification of proportions of SV40 RNA in labeled RNA from transformed lines and the characterization of SV40 RNAs by electrophoresis and cell-free translation. A 3.7-kb SV40 RNA from SV80 cells was discovered in this work.

A role for glucocorticoids in the polyphosphoinositide second messenger system

Glucocorticoids have been shown to be involved in numerous secretory and activation processes which are known to be mediated by the polyphosphoinositide second messenger system. A connection between glucocorticoids and the polyphosphoinositide system has not been made because of the marked temporal differences in their effects and the fact that most of the known effects of glucocorticoids involve transcription and/or protein synthesis. An attempt is made to to rationalize these apparent incongruities. The recently reported stimulation of glucose transport by kinase C suggests an experimental system to investigate glucocorticoid effects on the polyphosphoinositide system.

An adventitious role of cortisol in degenerative processes due to decreased opposition by insulin: Implications for aging

Cortisol can be implicated as contributing to a number of degenerative processes including arteriosclerosis, atherosclerosis, diabetes, and deterioration of muscle and the immune system. These effects of cortisol are amplified in diabetes due to a diminished opposition by insulin. In addition, this phenomena may not be restricted to diabetes. There is evidence that tissue sensitivity to insulin generally decreases with age, although insulin levels and metabolism may remain constant; this is not generally true for cortisol. This results in an increased cortisol activity with some pathological consequences which are most evident in vascular connective tissue and the immune system. The decrease in tissue responsiveness to insulin with respect to cortisol may reflect relative aging differences in the corresponding receptor-effector systems.