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Biomedical subjects

P Dodek

Publications and source records attributed to P Dodek.

At least 19 recordsLinked to original sources
PubMed2001

Cardiopulmonary resuscitation directives on admission to intensive-care unit: an international observational study.

BACKGROUND: Resuscitation directives should be a sign of patient's preference. Our objective was to ascertain prevalence, predictors, and procurement pattern of cardiopulmonary resuscitation directives within 24 h of admission to the intensive-care unit (ICU). METHODS: We enrolled 2916 patients aged 18 years and older from 15 ICUs in four countries, and recorded whether, when, and by whom their cardiopulmonary resuscitation directives were established. By polychotomous logistic regression we identified factors associated with a resuscitate or do-not-resuscitate directive. FINDINGS: Of 2916 patients, 318 (11%; 95% CI 9.8-12.1) had an explicit resuscitation directive. In 159 (50%; 44.4-55.6) patients, the directive was do-not-resuscitate. Directives were established by residents for 145 (46%; 40.0-51.3) patients. Age strongly predicted do-not-resuscitate directives: for 50-64, 65-74, and 75 years and older, odds ratios were 3.4 (95% CI 1.6-7.3), 4.4 (2.2-9.2), and 8.8 (4.4-17.8), respectively. APACHE II scores greater than 20 predicted resuscitate and do-not-resuscitate directives in a similar way. An explicit directive was likely for patients admitted at night (odds ratio 1.4 [1.0-1.9] and 1.6 [1.2-2.3] for resuscitate and do-not-resuscitate, respectively) and during weekends (1.9 [1.3-2.7] and 2.2 [1.5-3.2], respectively). Inability to make a decision raised the likelihood of a do-not-resuscitate (3.7 [2.6-5.4]) than a resuscitate (1.7 [1.2-2.3]) directive (p=0.0005). Within Canada and the USA, cities differed strikingly, as did centres within cities. INTERPRETATION: Cardiopulmonary resuscitation directives established within 24 h of admission to ICU are uncommon. As well as clinical factors, timing and location of admission might determine rate and nature of resuscitation directives.

APACHE↗
PubMed2001

Prevention and diagnosis of venous thromboembolism in critically ill patients: a Canadian survey.

BACKGROUND: Venous thromboembolism (VTE) confers considerable morbidity and mortality in hospitalized patients, although few studies have focused on the critically ill population. The objective of this study was to understand current approaches to the prevention and diagnosis of deep venous thrombosis (DVT) and pulmonary embolism (PE) among patients in the intensive care unit (ICU). DESIGN: Mailed self-administered survey of ICU Directors in Canadian university affiliated hospitals. RESULTS: Of 29 ICU Directors approached, 29 (100%) participated, representing 44 ICUs and 681 ICU beds across Canada. VTE prophylaxis is primarily determined by individual ICU clinicians (20/29, 69.0%) or with a hematology consultation for challenging patients (9/29, 31.0%). Decisions are usually made on a case-by-case basis (18/29, 62.1%) rather than by preprinted orders (5/29, 17.2%), institutional policies (6/29, 20.7%) or formal practice guidelines (2/29, 6.9%). Unfractionated heparin is the predominant VTE prophylactic strategy (29/29, 100.0%) whereas low molecular weight heparin is used less often, primarily for trauma and orthopedic patients. Use of pneumatic compression devices and thromboembolic stockings is variable. Systematic screening for DVT with lower limb ultrasound once or twice weekly was reported by some ICU Directors (7/29, 24.1%) for specific populations. Ultrasound is the most common diagnostic test for DVT; the reference standard of venography is rarely used. Spiral computed tomography chest scans and ventilation-perfusion scans are used more often than pulmonary angiograms for the diagnosis of PE. ICU Directors recommend further studies in the critically ill population to determine the test properties and risk:benefit ratio of VTE investigations, and the most cost-effective methods of prophylaxis in medical-surgical ICU patients. INTERPRETATION: Unfractionated subcutaneous heparin is the predominant VTE prophylaxis strategy for critically ill patients, although low molecular weight heparin is prescribed for trauma and orthopedic patients. DVT is most often diagnosed by lower limb ultrasound; however, several different tests are used to diagnose PE. Fundamental research in critically ill patients is needed to help make practice evidence-based.

Anticoagulants↗
PubMed2001

Underutilization of acute care settings in a tertiary care hospital.

OBJECTIVE: To estimate underutilization of acute care settings in a tertiary care hospital. DESIGN: A retrospective and concurrent cohort study using chart reviews and the Intensity of service, Severity of illness, Discharge screen for Acute Care (ISD-AC(R)) tool to measure appropriateness of acute care for patients who were receiving care in a less acute setting, as an indicator of underutilization. SETTING: A 450-bed tertiary care teaching hospital. STUDY PARTICIPANTS: Patients discharged from the emergency department, patients discharged from acute care inpatient units and patients in acute, non-critical care settings. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The percentage of patients discharged from the emergency department who did not meet the criteria for acute care discharge screens; the percentage of patients discharged from an acute care inpatient unit who did not meet the criteria for discharge screens; and the percentage of patients who were in acute, non-critical care beds and who met the criteria for critical care. RESULTS: It was found that six out of 168 patients [3.57%; 95% confidence interval (CI), 1.32-7.61%] did not meet the discharge screens at the time of discharge from the emergency department. Four out of 156 patients (2.56%; 95% CI, 0.70-6.43%) did not meet the discharge screens at the time of discharge from an acute care inpatient service and two out of 156 acute care patients (1.33%; 95% CI, 0.02-4.73%) who were in non-critical care beds met the criteria for critical care. CONCLUSION: These findings of underutilization may help to quantitate an unmet need in health care.

Acute Disease↗
PubMed2001

Intravenous insulin nomogram improves blood glucose control in the critically ill.

OBJECTIVE: To improve control of blood glucose concentrations in critically ill patients through use of a bedside, nurse-managed, intravenous insulin nomogram. DESIGN: Retrospective, before-after cohort study. SETTING: Fifteen-bed mixed medical/surgical intensive care unit in a tertiary, teaching hospital. PATIENTS: A total of 167 intensive care unit patients requiring intravenous insulin infusions during two 9-month periods. INTERVENTION: The sliding scale group was treated using ad hoc sliding scale infusion therapy. The intervention group was treated using a dosing nomogram that allowed the nurse to adjust the insulin infusion rate based on current glucose concentration and concurrent insulin infusion rates. The adjustments were made independent of physician input. MEASUREMENTS AND MAIN RESULTS: Time from initiating the insulin infusion to initial control of glucose concentration (<11.5 mmol/L) was determined. Effectiveness of glucose control was determined retrospectively by measuring the area under the curve of blood concentrations >11.5 mmol/L versus time of insulin infusion, divided by total duration of insulin infusion. The median time to initial control of glucose (<11.5 mmol/L) was 4 hr (range 1-38 hr) for the baseline and 2 hr (range 1-22 hr) for nomogram group (p =.0004). The median area under the curve of glucose concentration divided by duration of insulin infusion was 0.9 (range 0.0-5.9) for sliding scale group and 0.3 (range 0.0-11.1) for nomogram (p =.0001), without any increase in the frequency of episodes of hypoglycemia. CONCLUSION: Use of an insulin nomogram in critically ill patients improves control of blood glucose concentrations and is safe.

Area Under Curve↗
PubMed1999

Questionable history of immediate-type hypersensitivity to penicillin in Staphylococcal endocarditis: treatment based on skin-test results vers-us empirical alternative treatment--A decision analysis.

Approximately 10% of the population claim to be allergic to penicillins, but only approximately 10%-30% of these have IgE-mediated reactions to penicillin skin tests. Alternatives to penicillins may be less effective, more toxic, and more expensive. Therefore, we used decision analysis to calculate maximum expected utility and minimum cost for skin-testing or not skin-testing patients who have endocarditis due to Staphylococcus aureus that is susceptible to cloxacillin and who have a questionable history of immediate-type hypersensitivity to penicillin. We used known probabilities of intermediate outcomes, actual costs, and measured utilities and included one-way sensitivity analysis. Whether utility, cost, or average cost-utility was the outcome of interest, skin-testing was preferred to no skin-testing in most conditions. Patients who have endocarditis due to S. aureus that is susceptible to cloxacillin and who also have a questionable history of immediate-type hypersensitivity to penicillin should be skin-tested before starting antibiotic therapy.

Cloxacillin↗
PubMed1999

Discordance between physicians and coders in assignment of diagnoses.

OBJECTIVE: To measure concordance between physicians and medical record coders in their assignment of diagnoses. DESIGN: Prospective cohort series. SETTING: Five hundred and fifty-bed, tertiary-care, university teaching hospital. Study participants. In-patients who were discharged from either the Cardiac Sciences Program (n=125), the Renal Program (n=43), or the HIV-AIDS Program (n=25) during the period May 18-July 1, 1995. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Physicians and coders assigned diagnoses for individual in-patients based on their independent interpretations of the patient chart and discharge summary sheet. All assigned diagnoses were coded using the ICD-9-CM classification system. Concordance was measured for the most responsible diagnosis and for all assigned diagnoses. Difference in calculated resource intensity weights based on physicians' and coders' assignment of diagnoses was also calculated. RESULTS: Concordance rates for the most responsible diagnosis in each program were: Cardiac Sciences [27%; 95% confidence interval (CI)=20-36%], Renal Program (35%; 95% CI=21-53%), and HIV-AIDS Program (20%; 95% CI, 6-41%). Concordance rates for all diagnoses per chart were similar: Cardiac Sciences (20%; 95% CI, 14-25%), Renal Program (25%; 95% CI, 20-33%), and HIV-AIDS Program (29%; 95% CI, 25-44%). Resource intensity weights assigned by coders for the Cardiac Sciences and HIV-AIDS Program were significantly higher than those assigned by the physicians.

Abstracting and Indexing↗
PubMed1998

Implementation of a clinical practice guideline for stress ulcer prophylaxis increases appropriateness and decreases cost of care.

OBJECTIVE: To develop, implement and evaluate a practice guideline for stress ulcer prophylaxis. DESIGN: Before-after study. SETTING: Ten-bed Intensive Care Unit (ICU) and 4-bed Step-down Unit in a teaching hospital. PATIENTS AND PARTICIPANTS: Fifty patients admitted during 1 year before and 50 patients admitted 3-6 months after introduction of the guideline. INTERVENTION: Introduction of the practice guideline by dissemination of pocket cards, seminars and "academic detailing". MEASUREMENTS AND RESULTS: Appropriateness (defined as proportion of days in which the prophylaxis met the criteria in the guideline), incidence of gastrointestinal bleeding and of ventilator-associated pneumonia, length of stay in ICU and in hospital, ventilator days. ICU mortality and medication costs for stress ulcer prophylaxis. After the introduction of the guideline, appropriateness increased from 75.8% to 91.1%, and medication costs decreased from C $2.50/day to C $1.30/day. There were no differences in any clinical outcomes. Predictors of appropriate use or the withholding of prophylaxis were the introduction of the guideline, lack of an indication for prophylaxis and number of days studied. CONCLUSIONS: Introduction of this guideline was associated with an increase in appropriateness of prophylaxis and a decrease in medication costs.

Algorithms↗
PubMed1997

An evaluation of empiric vs. nomogram-based dosing of heparin in an intensive care unit.

OBJECTIVE: To compare the time to achieve therapeutic anticoagulation with heparin using two dosing methods. DESIGN: A retrospective before and after time series. SETTING: An 11-bed medical-surgical intensive care unit of a tertiary, teaching hospital. PATIENTS: Critically ill patients who required full dose anticoagulation as part of treatment of hemodynamic or respiratory failure. INTERVENTION: The use of a weight-based dosing nomogram with independent adjustment of infusion rates by nursing staff utilizing the nomogram dosing directions. This nomogram was compared with prior empiric heparin dosing by physicians. MEASUREMENTS AND MAIN RESULTS: The time to achieve a therapeutic activated partial thromboplastin time (PTT) (> 60 secs) was significantly less during use of the nomogram than during use of the empiric dosing method. The number of adjustments required to achieve the therapeutic PTT was less during use of the nomogram. Heparin dosing using the nomogram resulted in larger initial heparin infusion rates (unit/kg) and significantly higher initial PTT results. There was no difference in the initial bolus dose, time to first measured PTT, number of PTT measurements outside the therapeutic range, or signs of toxicity from subtherapeutic or supratherapeutic anticoagulation. CONCLUSIONS: Use of a weight-based heparin dosing nomogram by intensive care unit nursing staff can shorten the time to achieve therapeutic anticoagulation compared with empiric dosing by physicians.

Anticoagulants↗
PubMed1996

Reduced length of stay and improved appropriateness of care with a clinical path for total knee or hip arthroplasty.

BACKGROUND: In 1991 the orthopedics department at St Paul's Hospital, Vancouver, British Columbia, Canada, identified the clinical path as a way to shorten length of stay, improve efficiency of resource use, and minimize variation in care processes without compromising clinical outcomes for patients admitted for elective knee or hip arthroplasty. METHODS: A team of direct care providers collected baseline data for 77 patients to identify variables influencing length of stay (LOS) and variability in care processes. The team proposed an improved sequence of coordinated clinical decisions and treatments on a daily basis. The clinical path was disseminated by educating nursing and medical staff and by developing pre-printed orders and modifying the nursing care plan. RESULTS: Nine months after implementation of the clinical path, there was a statistically significant reduction in median LOS (12 to 9 days; p < 0.001), which was sustained for at least 18 additional months. Decreased use of inappropriate perioperative antibiotics and laboratory tests and no change in postoperative complications or readmission rate were also found. DISCUSSION: A new team is now developing a clinical path for hip fracture patients. In addition, other programs are using the template employed by the arthroplasty team to develop clinical paths for acute myocardial infarction, coronary artery bypass grafting, stroke, and drug overdose in the intensive care unit. SUMMARY: The team is now working toward a seven-day LOS for these patients. This experience has served as a model for development and implementation of other clinical paths for other groups of patients at the hospital.

British Columbia↗
PubMed1988

Exchange of labeled bicarbonate and carbon dioxide with erythrocytes suspended in an elutriator.

An elutriator was used to study exchange of labeled CO2 and bicarbonate with erythrocytes. Rabbit erythrocytes were suspended by centrifugation in a stream of fluid and exposed to transient injections of an extracellular indicator (125I-albumin or 22Na+), a water indicator (3H2O), and H14CO3- and/or 14CO2. Diffusion of indicators into erythrocytes was judged by comparison of initial concentrations of diffusible and extracellular indicators in the elutriator outflow. It was possible to conduct these experiments at normal hematocrits because any carbonic anhydrase released from erythrocytes by hemolysis was washed away in the elutriator flow, and ambient pH, PO2, and PCO2 were kept constant by the inflow of fresh fluid. Equilibration of HCO3- with erythrocytes was complete during the 7- to 10-s transit time through the chamber. After this exchange was irreversibly inhibited by the anion exchange inhibitor, DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonic acid), addition of carbonic anhydrase (100 mg/dl) accelerated exchange, but acetazolamide (20 mg/dl) was without effect. These observations were consistent with the absence of carbonic anhydrase on the surface of the erythrocytes.

Animals↗
PubMed1987

Estimation of endothelial receptor sites with the mean transit time approach.

A new procedure for quantitating endothelial receptor sites is described. The mean transit time of the passage of an appropriate radio-labeled ligand from the artery to vein of an organ is compared to the mean transit times of a vascular indicator and a water label. The concentration of the unlabeled ligand is progressively increased to define that concentration at which half of the enzyme sites are occupied. Values are calculated for the number of receptor sites accessible during a single circulation in each ml of exchangeable tissue water. This approach is illustrated by estimating the sites of carbonic anhydrase present on the pulmonary endothelium, utilizing labeled acetazolamide as a ligand. Preliminary studies of the receptor sites on isolated endothelial cells suspended in an elutriator are also presented.

Acetazolamide↗
PubMed1978

Effect of fasting on free and esterified carnitine levels in human serum and urine: correlation with serum levels of free fatty acids and beta-hydroxybutyrate.

Serum levels of free L-carnitine, acylcarnitines, creatinine, beta-hydroxybutyrate, free fatty acids, cholesterol, triglycerides, and glucose were determined in healthy volunteers during a 24-36-hr fast. The effect of oral administration of free L-carnitine (1 g/person) on these parameters was studied. Urinary excretion of carnitine and creatinine was monitored throughout. Serum and urine levels of free carnitine and its renal clearance decreased during the fast. However, the serum concentration and urinary excretion of acylcarnitines increased during the same interval. Following the ingestion of free L-carnitine, both serum and urinary levels of free L-carnitine rose. Within 6 hr of ingestion, 10% of the administered dose could be accounted for by urinary excretion. No significant effect on the other serum constituents under study was seen following the oral L-carnitine dose. A significant negative correlation was found between serum levels of free L-carnitine and beta-hydroxybutyrate and free fatty acids (r equal -0.567, p less than 0.001 and r equal -0.607, p less than 0.001, respectively) during the fast.

Acetylcarnitine↗
PubMed1976

Automated method for L-carnitine determination.

Because of renewed interest in a possible connection between carnitine, lipid disorders, and myopathy, an automated method of analysis is desirable. Deproteinization of serum by use of membrane filter cones and automated assay with a bichromatic analyzer (the ABA-100) substantially increases efficiency without sacrificing the specificity and accuracy of the original manual enzymatic method. The described procedure allows for analysis of 80 speciments a day and is thus suitable for screening of selected populations. Normal values found in blood sera of adults were in the range of 25.0-73.8 mu mol/liter and the method has sufficient sensitivity to accurately measure concentrations as small as 10 mu mol/liter.

Adult↗
PubMed1975

High glucose concentration and phosphoenolpyruvate carboxykinase activity in human and rat fetal liver cultures.

In cultures of human and rat fetal liver, phosphoenolpyruvate carboxykinase activity increases during the first 24 hr of culturing. This increase can be suppressed by adding cycloheximide to the culture medium or by adding a high glucose concentration. This, however, applies only to human fetal liver and to fetal liver from rats obtained just before term. In younger rat fetal liver, glucose, on the contrary, increases the activity of phosphoenolpyruvate carboxykinase. A high glucose concentration in the medium also leads to higher citrate cleavage enzyme activity and to lower alpha-glycerolphosphate dehydrogenase (cytoplasmic) activity in rat fetal liver cultures.

Animals↗