[show abstract][hide abstract] ABSTRACT: Cardiac troponins are sensitive and specific biomarkers of myocardial necrosis. We evaluated troponin, creatine kinase (CK), and electrocardiogram (ECG) abnormalities in patients with septic shock; and compared the effect of vasopressin (VP) vs norepinephrine (NE) on troponin, CK, and ECGs.
This was a prospective substudy of a randomized trial. Adults with septic shock randomly received a blinded infusion of low-dose VP (0.01-0.03 U/min) or NE (5-15 mug/min) in addition to open-label vasopressors, titrated to maintain a mean blood pressure of 65-75 mmHg. Troponin I/T, CK, and CKMB were measured and 12-lead ECGs were recorded prior to study drug, and 6 hours, 2 days and 4 days after study drug initiation. Two physician readers, blinded to patient data and drug, independently interpreted ECGs.
We enrolled 121 patients [median age 63.9 years (IQR 51.1,75.3), mean Acute Physiology and Chronic Health Evaluation II (APACHE II) 28.6 (SD 7.7)]: 65 in VP group and 56 in NE group. At the 4 timepoints, 26%, 36%, 32% and 21% of patients had troponin elevations, respectively. Baseline characteristics and outcomes were similar between patients with positive versus negative troponin levels. Troponin and CK levels, and rates of ischemic ECG changes were similar in the VP and NE groups. In multivariable analysis only APACHE II was associated with 28-day mortality (OR 1.07, 95% CI 1.01-1.14, p=0.033).
Troponin elevation is common in adults with septic shock. We observed no significant differences in troponin, CK, and ECGs in patients treated with vasopressin and norepinephrine. Troponin elevation was not an independent predictor of mortality.
Critical care (London, England) 06/2013; 17(3):R117. · 4.72 Impact Factor
[show abstract][hide abstract] ABSTRACT: Objective: The reliability of electrocardiogram interpretation to diagnose myocardial ischemia in critically ill patients is unclear. In adults with septic shock, we assessed intra- and inter-rater agreement of electrocardiogram interpretation, and the effect of knowledge of troponin values on these interpretations.
Design: Prospective substudy of a randomized trial of vasopressin vs. norepinephrine in septic shock.
Setting: Nine Canadian intensive care units.
Patients: Adults with septic shock requiring at least 5 μg/min of norepinephrine for 6 hrs.
Interventions: Twelve-lead electrocardiograms were recorded before study drug, and 6 hrs, 2 days, and 4 days after study drug initiation.
Measurements: Two physician readers, blinded to patient data and group, independently interpreted electrocardiograms on three occasions (first two readings were blinded to patient data; third reading was unblinded to troponin). To calibrate and refine definitions, both readers initially reviewed 25 trial electrocardiograms representing normal to abnormal. Cohen's Kappa and the φ statistic were used to analyze intra- and inter-rater agreement.
Results: One hundred twenty-one patients (62.2 ± 16.5 yrs, Acute Physiology and Chronic Health Evaluation II 28.6 ± 7.7) had 373 electrocardiograms. Blinded to troponin, readers 1 and 2 interpreted 46.4% and 30.0% of electrocardiograms as normal, and 15.3% and 12.3% as ischemic, respectively. Intrarater agreement was moderate for overall ischemia (κ 0.54 and 0.58), moderate/good for “normal” (κ 0.69 and 0.55), fair to good for specific signs of ischemia (ST elevation, T inversion, and Q waves, reader 1 κ 0.40 to 0.69; reader 2 κ 0.56 to 0.70); and good/very good for atrial arrhythmias (κ 0.84 and 0.79) and bundle branch block (κ 0.88 and 0.79). Inter-rater agreement was fair for ischemia (κ 0.29), moderate for ST elevation (κ 0.48), T inversion (κ 0.52), and Q waves (κ 0.44), good for bundle branch block (κ 0.78), and very good for atrial arrhythmias (κ 0.83). Inter-rater agreement for ischemia improved from fair to moderate (κ 0.52, p = .028) when unblinded to troponin.
Conclusions: In patients with septic shock, inter-rater agreement of electrocardiogram interpretation for myocardial ischemia was fair, and improved with troponin knowledge.
Critical Care Medicine 08/2011; 39(9):2080-2086. · 6.12 Impact Factor