18 Nov 09
Posted in Cardiac arrest/Resuscitation, ECG, Pre-operatie evaluation at 21:20 by Laci
By J Tikkanen, O Anttonen, M Junttila, A Aro, T Kerola, H Rissanen, A Reunanen and H Huikuri
NEJM 2009;361:2529-2537
Early repolarization, which is characterized by an elevation of the QRS–ST junction (J point) in leads other than V1 through V3 on 12-lead electrocardiography, has been associated with vulnerability to ventricular fibrillation, but little is known about the prognostic significance of this pattern in the general population.
Methods
We assessed the prevalence and prognostic significance of early repolarization on 12-lead electrocardiography in a community-based general population of 10,864 middle-aged subjects (mean [±SD] age, 44±8 years). The primary end point was death from cardiac causes, and secondary end points were death from any cause and death from arrhythmia during a mean follow-up of 30±11 years. Early repolarization was stratified according to the degree of J-point elevation (0.1 mV or >0.2 mV) in either inferior or lateral leads.
Results
The early-repolarization pattern of 0.1 mV or more was present in 630 subjects (5.8%): 384 (3.5%) in inferior leads and 262 (2.4%) in lateral leads, with elevations in both leads in 16 subjects (0.1%). J-point elevation of at least 0.1 mV in inferior leads was associated with an increased risk of death from cardiac causes (adjusted relative risk, 1.28; 95% confidence interval [CI], 1.04 to 1.59; P=0.03); 36 subjects (0.3%) with J-point elevation of more than 0.2 mV in inferior leads had a markedly elevated risk of death from cardiac causes (adjusted relative risk, 2.98; 95% CI, 1.85 to 4.92; P<0.001) and from arrhythmia (adjusted relative risk, 2.92; 95% CI, 1.45 to 5.89; P=0.01). Other electrocardiographic risk markers, such as a prolonged QT interval corrected for heart rate (P=0.03) and left ventricular hypertrophy (P=0.004), were weaker predictors of the primary end point.
Conclusions
An early-repolarization pattern in the inferior leads of a standard electrocardiogram is associated with an increased risk of death from cardiac causes in middle-aged subjects.
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16 Nov 09
Posted in Glycemic control, Monitoring at 4:00 by Laci
By I Meynaar, M van Spreuwel, P Tangkau, L Dawson, S Visser, L Rijks, T Vlieland
Crit Care Med 2009; 37:2691-2696
To evaluate the accuracy of the AccuChek Inform point-of-care glucose measurement device as compared with central laboratory glucose measurement.
Design
Prospective, observational study.
Setting
A ten-bed mixed closed format intensive care unit in a 500-bed general hospital. The unit has a computerized insulin protocol aiming for 81 to 135 mg/dL.
Patients
All intensive care unit patients were eligible.
Interventions
None.
Measurements and main results
Paired samples (AccuChek glucose in whole blood calibrated to give whole blood results and central laboratory glucose in serum) were taken simultaneously. In 32 critically ill patients, we obtained the following information: mean ± standard deviation age 71.6 ± 11.9 yrs; mean Acute Physiology and Chronic Health Evaluation II score at admission 17.8 ± 6.7; 239 paired samples were taken from arterial catheters. Mean AccuChek whole blood glucose was 126 ± 36 mg/dL (7.0 ± 2.0 mmol/L); mean central laboratory serum glucose was 137 ± 38 mg/dL (7.6 ± 2.1 mmol/L). Mean difference was 11 mg/dL (0.61 mmol/L) (8%) (95% Confidence Interval = 9-13 mg/dL, p < .001). ISO 15197 guideline requires 95% of point-of-care measurements to be within 15 mg/dL margins with reference <75 mg/dL or within 20% if reference is higher. In total, 216 (90.4%) of AccuChek measurements were within ISO 15197 margins. Because AccuChek was calibrated to give whole blood results, we calculated a correction factor of 1.086 from the two mean values to correct whole blood AccuChek into serum-like results. This is almost the same as the correction factor of 1.080 given by Roche Diagnostics. By multiplying AccuChek whole blood results with 1.086, 225 (94.1%) of results were within the ISO 15197 margins. Hematocrit did not influence AccuChek results in the 0.20 to 0.44 range. Beyond this range, there were not enough data to draw conclusions.
Conclusions
In critically ill patients, the accuracy of AccuChek glucose measurement calibrated to give serum-like results with blood samples derived from arterial catheters is acceptable but falls short by about 1% of complying with the ISO 15197 guideline.
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14 Nov 09
Posted in Cardiac arrest/Resuscitation, Hypothermia at 2:31 by Laci
ByC Don, W Longstreth, C Maynard, M Olsufka, G Nichol, T Ray et al
Crit Care Med – published ahead of print
To evaluate whether implementation of a therapeutic hypothermia protocol on arrival in a community hospital improved survival and neurologic outcomes in patients initially found to have ventricular fibrillation, pulseless electrical activity, or asystole, and then successfully resuscitated from out-of-hospital cardiac arrest.
Design
A retrospective study of patients who presented after implementation of a therapeutic hypothermia protocol compared with those who presented before the protocol was implemented.
Setting
Harborview Medical Center, Seattle, WA.
Patients
A total of 491 consecutive adults with out-of-hospital, nontraumatic cardiac arrest who presented between January 1, 2000 and December 31, 2004.
Interventions
An active cooling therapeutic hypothermia protocol, using ice packs, cooling blankets, or cooling pads to achieve a temperature of 32oC to 34oC was initiated on November 18, 2002 for unconscious patients resuscitated from cardiac arrest.
Measurements and main results
Demographics and outcomes were obtained from medical records and an emergency medical database. The primary outcomes were survival and favorable neurologic outcome at discharge associated with the therapeutic hypothermia protocol. An adjusted analysis was performed, using a multivariate regression. During the therapeutic hypothermia period, 204 patients were brought to the emergency department; of these 204 patients, 132 (65%) ultimately achieved temperatures of <34oC. Of the 72 patients who did not achieve goal temperatures: 40 (20%) died in the emergency department or shortly after being admitted to the hospital, 15 (7%) regained consciousness, four (2%) had contraindications, 13 (6%) had temperature increase or did not have documented use of the therapeutic hypothermia protocol. In the prior period, none of the 287 patients received active cooling. Patients admitted in the therapeutic hypothermia period had a mean esophageal temperature of 34.1oC during the first 12 hrs compared with 35.2oC in the pretherapeutic hypothermia period (p < 0.01). Survival to hospital discharge improved in the therapeutic hypothermia period in patients with an initial rhythm of ventricular fibrillation (odds ratio = 1.88, 95% confidence interval = 1.03-3.45), however not in patients with nonventricular fibrillation (odds ratio = 1.17, 95% confidence interval = 0.66-2.05). In adjusted analysis, ventricular fibrillation patients during the therapeutic hypothermia period trended toward improved survival (odds ratio = 1.71, 95% confidence interval = 0.85-3.46) and had favorable neurologic outcome (odds ratio = 2.62, 95% confidence interval = 1.1-6.27) compared with the earlier period. This benefit was not observed in patients whose initial rhythm was pulseless electrical activity or asystole.
Conclusions
The therapeutic hypothermia period was associated with a significant improvement in neurologic outcomes in patients whose initial rhythm was ventricular fibrillation, but not in patients with other rhythms.
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13 Nov 09
Posted in Mechanical ventilation at 2:27 by Laci
By C Teixeira, N da Silva, A Savi, S Rios Vieira, L Nasi, G Friedman et al
Crit Care Med – published ahead of print
To evaluate the predictive value of central venous saturation to detect extubation failure in difficult-to-wean patients.
Design
Cohort, multicentric, clinical study.
Setting
Three medical-surgical intensive care units.
Patients
All difficult-to-wean patients (defined as failure to tolerate the first 2-hr T-tube trial), mechanically ventilated for >48 hrs, were extubated after undergoing a two-step weaning protocol (measurements of predictors followed by a T-tube trial). Extubation failure was defined as the need of reintubation within 48 hrs.
Interventions
The weaning protocol evaluated hemodynamic and ventilation parameters, and arterial and venous gases during mechanical ventilation (immediately before T-tube trial), and at the 30th min of spontaneous breathing trial.
Measurements and main results
Seventy-three patients were enrolled in the study over a 6-mo period. Reintubation rate was 42.5%. Analysis by logistic regression revealed that central venous saturation was the only variable able to discriminate outcome of extubation. Reduction of central venous saturation by >4.5% was an independent predictor of reintubation, with odds ratio of 49.4 (95% confidence interval = 12.1-201.5), a sensitivity of 88%, and a specificity of 95%. Reduction of central venous saturation during spontaneous breathing trial was associated with extubation failure and could reflect the increase of respiratory muscles oxygen consumption.
Conclusions
Central venous saturation was an early and independent predictor of extubation failure and may be a valuable accurate parameter to be included in weaning protocols of difficult-to-wean patients.
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