Mathijs Vogelzang

Design and implementation of GRIP: a computerized glucose control system at a surgical intensive care unit

BackgroundTight glucose control by intensive insulin therapy has become a key part of critical care and is an important field of study in acute coronary care. A balance has to be found between frequency of measurements and the risk of hypoglycemia. Current nurse-driven protocols are paper-based and, therefore, rely on simple rules. For safety and efficiency a computer decision support system that employs complex logic may be superior to paper protocols.MethodsWe designed and implemented GRIP, a stand-alone Java computer program. Our implementation of GRIP will be released as free software. Blood glucose values measured by a point-of-care analyzer were automatically retrieved from the central laboratory database. Additional clinical information was asked from the nurse and the program subsequently advised a new insulin pump rate and glucose sampling interval.ResultsImplementation of the computer program was uneventful and successful. GRIP treated 179 patients for a total of 957 patient-days. Severe hypoglycemia (< 2.2 mmol/L) only occurred once due to human error. With a median (IQR) of 4.9 (4.2 – 6.2) glucose measurements per day the median percentage of time in which glucose fell in the target range was 78%. Nurses rated the program as easy to work with and as an improvement over the preceding paper protocol. They reported no increase in time spent on glucose control.ConclusionA computer driven protocol is a safe and effective means of glucose control at a surgical ICU. Future improvements in the recommendation algorithm may further improve safety and efficiency.

Incidence and clinical consequences of distal embolization on the coronary angiogram after percutaneous coronary intervention for ST-elevation myocardial infarction

AIMS We investigated the incidence and sequelae of angiographically visible distal embolization (AVDE) after primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction patients treated with aspirin, heparin, clopidogrel, and glycoprotein-IIb/IIIa inhibitors. METHODS AND RESULTS As part of TAPAS, AVDE was a predefined secondary endpoint. We compared angiographic and clinical characteristics, and outcomes of patients with and without AVDE after PCI. AVDE was present on 6.3% of 883 post-procedural angiograms. Angiographically visible distal embolization was associated with significantly worse outcomes, as expressed by lower myocardial blush grade, impaired ST-segment resolution, and higher enzyme levels (all P </= 0.001). Mortality 1 year after PCI was 4 of 56 (7.1%) in patients with AVDE and 43 of 827 (5.2%) in patients without AVDE (P= ns), re-infarction occurred in 5 of 56 (8.9%), and 25 of 827 (3.0%) patients (P = 0.018). The thrombus aspirate more often contained erythrocytes in patients with AVDE than in patients without AVDE (50.0% vs. 15.7%, P < 0.001), and the size of the aspirated thrombus was larger in patients with AVDE (P = 0.002). CONCLUSION In patients with triple anti-platelet therapy, the incidence of AVDE after PCI is low, compared with previous reports. Nevertheless, AVDE is associated with impaired myocardial reperfusion and poor outcome. Thrombus composition and size are related to AVDE after PCI.

Effect of High-Dose Intracoronary Adenosine Administration During Primary Percutaneous Coronary Intervention in Acute Myocardial Infarction A Randomized Controlled Trial

BACKGROUND Coronary microvascular dysfunction is frequently seen in patients with ST-elevation myocardial infarction after primary percutaneous coronary intervention. Previous studies have suggested that the administration of intravenous adenosine resulted in an improvement of myocardial perfusion and a reduction in infarct size. Intracoronary adenosine (bolus of 30 to 60 microg) is a guideline-recommended therapy to improve myocardial reperfusion. The effect of intracoronary adenosine during primary percutaneous coronary intervention has not been investigated in a large randomized trial. METHODS AND RESULTS Patients presenting with acute ST-elevation myocardial infarction were randomized to 2 bolus injections of intracoronary adenosine (2 x 120 microg in 20 mL NaCl) or placebo (2 x 20 mL NaCl). The first bolus injection was given after thrombus aspiration and the second after stenting of the infarct-related artery. The primary end point was the incidence of residual ST-segment deviation <0.2 mV, 30 to 60 minutes after percutaneous coronary intervention. Secondary end points were ST-segment elevation resolution, myocardial blush grade, Thrombolysis in Myocardial Infarction flow on the angiogram after percutaneous coronary intervention, enzymatic infarct size, and clinical outcome at 30 days. A total of 448 patients were randomized to intracoronary adenosine (N=226) or placebo (N=222). The incidence of residual ST-segment deviation <0.2 mV did not differ between patients randomized to adenosine or placebo (46.2% versus 52.2%, P=NS). In addition, there were no significant differences in secondary outcome measures. CONCLUSIONS In this randomized placebo controlled trial enrolling 448 patients with ST-elevation myocardial infarction, administration of intracoronary adenosine after thrombus aspiration and after stenting of the infarct-related artery did not result in improved myocardial perfusion.

Emergency trauma score: an instrument for early estimation of trauma severity.

Objectives:Early estimation of the mortality risk of severely injured patients is mandatory. To estimate the seriousness of the condition of patients with trauma, we developed the emergency trauma score (EMTRAS) for ease of use, with simple parameters that are available within 30 minutes. Design:Prospective analysis of the German Trauma Registry of multitrauma patients. Setting:EMTRAS was derived from data from 1993 through 2003. Potential parameters that were prognostic for mortality in univariate analysis were evaluated by multivariate binary logistic regression. Selected parameters were then assigned a subscore that varied from 0 to 3. The EMTRAS score was a simple addition of these subscores. EMTRAS was compared with other scores’ receiver operating characteristic curves. After completion, EMTRAS was validated in patients from 2004 and 2005. Patients:A total of 11,533 patients were to be used for developing the score and 3314 patients for validating it. Main Results:The strongest predictors of mortality were age, prehospital Glasgow Coma Scale, base excess (mmol/L), and prothrombin time (% of reference). These parameters were categorized in subscores of 0 through 3. Age: <40, 40 through 60, 61 through 75, and >75 scored 0, 1, 2, and 3, respectively. Glasgow Coma Scale: 13 through 15, 10 through 12, 6 through 9, and 3 through 5 scored 0, 1, 2, and 3, respectively. Base excess: >−1, −5 through −1, −10 through −5.1, and <−10 scored 0, 1, 2, and 3, respectively. Prothrombin time: <80%, 80% through 50%, 49% through 20%, and >20% received a score of 0, 1, 2, and 3, respectively. In the validation dataset, the area under the receiver operating characteristic curve for EMTRAS was 0.828. Conclusions:EMTRAS combines four early parameters from the emergency room and accurately predicts mortality. Knowledge of the anatomical injuries is not necessary. The determination of the EMTRAS will inform caregivers of the seriousness of patients with trauma at an early stage.

Effect of High-Dose Intracoronary Adenosine Administration During Primary Percutaneous Coronary Intervention in Acute Myocardial InfarctionCLINICAL PERSPECTIVE

BACKGROUND Coronary microvascular dysfunction is frequently seen in patients with ST-elevation myocardial infarction after primary percutaneous coronary intervention. Previous studies have suggested that the administration of intravenous adenosine resulted in an improvement of myocardial perfusion and a reduction in infarct size. Intracoronary adenosine (bolus of 30 to 60 microg) is a guideline-recommended therapy to improve myocardial reperfusion. The effect of intracoronary adenosine during primary percutaneous coronary intervention has not been investigated in a large randomized trial. METHODS AND RESULTS Patients presenting with acute ST-elevation myocardial infarction were randomized to 2 bolus injections of intracoronary adenosine (2 x 120 microg in 20 mL NaCl) or placebo (2 x 20 mL NaCl). The first bolus injection was given after thrombus aspiration and the second after stenting of the infarct-related artery. The primary end point was the incidence of residual ST-segment deviation <0.2 mV, 30 to 60 minutes after percutaneous coronary intervention. Secondary end points were ST-segment elevation resolution, myocardial blush grade, Thrombolysis in Myocardial Infarction flow on the angiogram after percutaneous coronary intervention, enzymatic infarct size, and clinical outcome at 30 days. A total of 448 patients were randomized to intracoronary adenosine (N=226) or placebo (N=222). The incidence of residual ST-segment deviation <0.2 mV did not differ between patients randomized to adenosine or placebo (46.2% versus 52.2%, P=NS). In addition, there were no significant differences in secondary outcome measures. CONCLUSIONS In this randomized placebo controlled trial enrolling 448 patients with ST-elevation myocardial infarction, administration of intracoronary adenosine after thrombus aspiration and after stenting of the infarct-related artery did not result in improved myocardial perfusion.

Implementation and evaluation of a nurse-centered computerized potassium regulation protocol in the intensive care unit - a before and after analysis

BackgroundPotassium disorders can cause major complications and must be avoided in critically ill patients. Regulation of potassium in the intensive care unit (ICU) requires potassium administration with frequent blood potassium measurements and subsequent adjustments of the amount of potassium administrated. The use of a potassium replacement protocol can improve potassium regulation. For safety and efficiency, computerized protocols appear to be superior over paper protocols. The aim of this study was to evaluate if a computerized potassium regulation protocol in the ICU improved potassium regulation.MethodsIn our surgical ICU (12 beds) and cardiothoracic ICU (14 beds) at a tertiary academic center, we implemented a nurse-centered computerized potassium protocol integrated with the pre-existent glucose control program called GRIP (Glucose Regulation in Intensive Care patients). Before implementation of the computerized protocol, potassium replacement was physician-driven. Potassium was delivered continuously either by central venous catheter or by gastric, duodenal or jejunal tube. After every potassium measurement, nurses received a recommendation for the potassium administration rate and the time to the next measurement. In this before-after study we evaluated potassium regulation with GRIP. The attitude of the nursing staff towards potassium regulation with computer support was measured with questionnaires.ResultsThe patient cohort consisted of 775 patients before and 1435 after the implementation of computerized potassium control. The number of patients with hypokalemia (<3.5 mmol/L) and hyperkalemia (>5.0 mmol/L) were recorded, as well as the time course of potassium levels after ICU admission. The incidence of hypokalemia and hyperkalemia was calculated. Median potassium-levels were similar in both study periods, but the level of potassium control improved: the incidence of hypokalemia decreased from 2.4% to 1.7% (P < 0.001) and hyperkalemia from 7.4% to 4.8% (P < 0.001). Nurses indicated that they considered computerized potassium control an improvement over previous practice.ConclusionsComputerized potassium control, integrated with the nurse-centered GRIP program for glucose regulation, is effective and reduces the prevalence of hypo- and hyperkalemia in the ICU compared with physician-driven potassium regulation.

Feasibility and applicability of computer-assisted myocardial blush quantification after primary percutaneous coronary intervention for ST-segment elevation myocardial infarction†

Objectives: The aim of the study was to evaluate whether the “Quantitative Blush Evaluator” (QuBE) score is associated with measures of myocardial reperfusion in patients with ST‐segment elevation myocardial infarction (STEMI) treated in two hospitals with 24/7 coronary intervention facilities. Background: QuBE is an open source computer program to quantify myocardial perfusion. Although QuBE has shown to be practical and feasible in the patients enrolled in the Thrombus Aspiration during Percutaneous Coronary Intervention in Acute Myocardial Infarction Study (TAPAS), QuBE has not yet been verified on reperfusion outcomes of primary percutaneous coronary intervention (PCI) patients treated in other catheterization laboratories. Methods: Core lab adjudicated angiographic outcomes and QuBE values were assessed on angiograms of patients who were enrolled in the PRoximal Embolic Protection in Acute myocardial infarction and Resolution of ST‐Elevation (PREPARE) trial. ST‐segment resolution immediately after PCI measured by continuous ST Holter monitoring was calculated by a blinded core lab. Results: The QuBE score could be assessed on 229 of the 284 angiograms (81%) and was significantly associated with visually assessed myocardial blush grade (P < 0.0001). Patients with improved postprocedural Thrombolysis in Myocardial Infarction‐graded flow, myocardial blush grade, ST‐segment resolution immediately after PCI, or a small infarct size measured by peak CK‐MB had a significant better QuBE score. Conclusions: QuBE is feasible and applicable at angiograms of patients with STEMI recorded at other catheterization laboratories and is associated with measures of myocardial reperfusion.

Determinants of renal potassium excretion in critically ill patients : The role of insulin therapy

Objectives:Insulin administration lowers plasma potassium concentration by augmenting intracellular uptake of potassium. The effect of insulin administration on renal potassium excretion is unclear. Some studies suggest that insulin has an antikaliuretic effect although plasma potassium levels were poorly controlled. Since the introduction of glycemic control in the intensive care unit, insulin use has increased. We examined the relation between administered insulin and renal potassium excretion in critically ill patients under computer-assisted glucose and potassium regulation. Design:Prospective observational study. Setting:Twelve-bed surgical intensive care unit of a university teaching hospital. Patients:Consecutive intensive care unit patients. Interventions:Potassium and glucose levels were regulated by a computer-assisted decision support system. Both potassium and insulin were continuously administered by syringe pump. Measurements and Main Results:Renal potassium excretion was measured daily in the 24-hr urine collections. The 24-hr urinary samples of patients with kidney failure or on renal replacement therapy were excluded. Multivariate analysis with potassium excretion as the dependent variable was performed. In 178 consecutive patients, 1,456 24-hr urinary samples, were analyzed. Mean ± SD plasma potassium was 4.2 ± 0.3 mmol/L, with 79 ± 46 mmol/d of potassium administered and a mean insulin dose of 53 ± 38 U/day. Renal potassium excretion was 126 ± 51 mmol/day. After multivariate analysis correcting for relevant variables (including diuretics, pH, potassium levels and renal sodium excretion), insulin administration was independently and positively associated with renal potassium excretion. Other significant variables were potassium levels, potassium administration, renal sodium and chloride excretion, creatinine clearance, diuretic therapy, pH, known diabetes and intensive care unit admission day (R2 = .52; p <. 001). Conclusion:Insulin administration is associated with an increase in the renal potassium excretion in critically ill patients.

Predictive value of Q waves on the 12-lead electrocardiogram after reperfusion therapy for ST elevation myocardial infarction

DESIGN The data used for the present study were obtained as part of a clinical trial evaluating the effect of thrombus aspiration after primary percutaneous coronary intervention (PCI). SETTING The study was conducted at a tertiary referral facility for primary PCI at a University Medical Center Groningen in The Netherlands. BACKGROUND Prognosis after ST elevation myocardial infarction (STEMI) is strongly related to infarct size. METHODS As part of a randomized clinical trial, the first electrocardiogram (ECG) after primary PCI for STEMI was analyzed for the incidence of Q waves (>0.1 mV) on the 12-lead ECG. Infarct size was measured as area under curve (AUC) of creatine kinase (CK) and CK-myocardial band (CK-MB). RESULTS AND CONCLUSION Nine hundred thirty-three patients were included, the median number of Q waves on the postprocedural ECG was 3 (interquartile range, 1-4). The number of Q waves on the postprocedural ECG was an independent predictor of infarct size measured either as AUC of CK (P < .001) or AUC of CK-MB (P < .001) and was a significant predictor of mortality during follow-up of 14 months. In conclusion, the number of Q waves on the postprocedural 12-lead ECG after primary PCI for STEMI is a strong predictor of infarct size and long-term mortality.

The impact of a reduced dose of dexamethasone on glucose control after coronary artery bypass surgery

BackgroundIntensive insulin therapy to maintain normoglycemia after cardiac surgery reduces morbidity and mortality. We investigated the magnitude and duration of hyperglycemia caused by dexamethasone administered after cardiopulmonary bypass.MethodsA single-center before-after cohort study was performed. All consecutive patients undergoing coronary artery bypass grafting with cardiopulmonary bypass during a 6-month period were included. Insulin administration was guided by a sliding scale protocol. Halfway the observation period, the dexamethasone protocol was changed. The single dose (1D) group received a pre-operative dose of dexamethasone of 1 mg/kg. The double dose group (2D) received an additional dose of 0.5 mg/kg of dexamethasone post-operatively at ICU admission.ResultsWe included 116 patients in the 1D group and 158 patients in the 2D group. There were no significant baseline differences between the groups. Median Euroscore was 5. In univariable analysis, the glucose level was different between groups 1D and 2D at 4, 6, 9, 12 and 24 hours after ICU admission (all p < 0.001). Insulin infusion was higher in the 1D group. Corrected for insulin dose in multivariable linear analysis, the difference in glucose between the 1D and 2D groups was 1.5 mmol/L (95% confidence interval 1.0–2.0, p < 0.001) 12 hours after ICU admission.ConclusionDexamethasone exerts a hyperglycemic effect in cardiac surgery patients. Patients receiving high-dose corticosteroid therapy should be monitored and treated more intensively for hyperglycemic episodes.