A randomized trial comparing two intraosseous access devices in intrahospital healthcare providers with a focus on retention of knowledge, skill, and self-efficacy.

INTRODUCTION: Intraosseous access is recommended in vitally compromised patients if an intravenous access cannot be easily obtained. Intraosseous infusion can be initiated by various healthcare providers. Currently, there are two mechanical intraosseous devices approved by the U.S. Food and Drug Administration (FDA) for use in adults and children. A comparison is made in this study of the theoretical and practical performance by anesthesiologists and registered nurses of anesthesia (RNAs) in the use of the battery-powered device (device A) versus the spring-loaded needle device (device B). This study entailed a 12-month follow-up of knowledge, skill retention, and self-efficacy measured by standardized testing. METHODS: A prospective randomized trial was performed, initially comparing 15 anesthesiologists and 15 RNAs, both on using the two types of intraosseous devices. A structured lecture and skill station was given with the educational aids provided by the respective manufacturers. Individual knowledge and practical skills were tested at 0, 3, and 12 months after the initial course. RESULTS: There was no statistical significant difference in the retention of theoretical knowledge between RNAs and anesthesiologists on all testing occasions. However, the self-efficacy of the anesthesiologists is significantly higher (p < 0.01) than the self-efficacy of the RNAs for both devices, on any testing occasion. Insufficient skills were local disinfection (both groups, both devices) and attachment of the needle to the intravenous line (RNAs with both devices). In 33 % of all device B handlings, unsafe practice occurred. CONCLUSION: The use of device A is safer in handling in comparison to device B at 12 months follow-up. The hypothesis that doctors are more qualified in obtaining intraosseous access has been disproven, as anesthesiologists were as successful as RNAs. However, the low self-efficacy of RNAs in the use of intraosseous devices could diminish the chance of them actually using one.

Effect of the colloids gelatin and HES 130/0.4 on blood coagulation in cardiac surgery patients: a randomized controlled trial.

OBJECTIVE: The choice of the prime solution for cardiopulmonary bypass can play an important role in limiting the effect on blood coagulation, but it is still unclear what the effect of colloids on blood coagulation is. The aim of this study was to investigate the effect of synthetic colloids on blood loss and blood coagulation in patients after on-pump coronary artery bypass graft (CABG) procedures. METHODS: Sixty elective, on-pump CABG patients were randomly assigned to receive the prime solutions lactated Ringer's solution combined with hydroxyethyl starch 130/0.4 (HES, 6% Volulyte, Fresenius Kabi Nederland BV, Zeist, the Netherlands) (HES group) or gelatin (Gelofusin(®), B Braun Melsung AG, Melsungen, Germany) (Gelo group). Blood loss was assessed using post-operative chest tube output; secondary endpoints were number of blood component transfusions, routine coagulation test values and rotation thromboelastometry values (Rotem(®) delta, Pentapharm GmbH, Munich, Germany). RESULTS: Total post-operative chest tube output was 500 ± 420 ml in the HES group versus 465 ± 390 ml in the Gelo group (p = 0.48). No significant differences were observed in any of the routine coagulation tests values, thromboelastometry parameters or number of blood component transfusions between the groups. CONCLUSIONS: In this randomized, controlled trial of adults after on-pump CABG procedures, there was no significant difference in blood loss or blood coagulation between the HES group and the Gelo group.

Clinical evaluation of a new tracheal impedance cardiography method.

Non-invasive cardiac output measurement by means of impedance cardiography has been evaluated before, and agreement with other methods has been variable. We decided to study a newly developed tracheal impedance device, that is claimed to be more accurate and reliable. This incorporates new software and mathematical formulae, that are designed to reduce signal noise from diathermy, leading to improved accuracy. In 25 cardiothoracic surgery patients, simultaneous measurements were performed using both pulmonary artery thermodilution and the tracheal impedance device, at five peri-operative time points: before skin incision; after weaning from cardiopulmonary bypass; after sternal closure; and 30 min and 2 h after arrival in the intensive care unit. Mean cardiac output, bias and 95% limits of agreement were 5.3, 0.03 and -2.8 to 2.8 l.min(-1) , respectively. Tracheal impedance showed good correlation with measurement trends using thermodilution in 88% of measurements, with a mean (95% limit of agreement) angular bias of -9.0° (-83.3 to 65.3°). However, the wide limits of agreement and high percentage error of 53% that were apparent in this study mean that, in its present guise, tracheal impedance is not an acceptable alternative to thermodilution in cardiac surgical patients.

Predictors of sustained ventricular arrhythmia episodes in patients with primary ICD indication: male gender and AF in primary ICD prophylaxis.

AIMS: Implantable cardioverter-defibrillators (ICD) reduce mortality in patients with severely impaired left ventricular function. In randomized studies, female patients are underrepresented and data on ICD therapy is limited. Atrial fibrillation (AF) is a determinant of poor prognosis but has not been consistently evaluated. We evaluated the risk factors for the occurrence of ventricular arrhythmia episodes in patients with primary ICD prophylaxis. METHODS: Consecutive patients after ICD implantation for primary prophylaxis were followed. During follow-up, detected sustained episodes of ventricular arrhythmia were documented. Multivariate analysis controlled for propensity score was used to evaluate the correlation between gender, history of AF, and the occurrence of ventricular arrhythmia episodes. RESULTS: A total of 400 patients (19.8% female; n = 79) were included. During follow-up, 64 patients (16%) had appropriate ICD therapy episodes. Men (18%) had significantly more often episodes than women (8%; p = 0.025). Patients with a history of AF (102, 25.5%) had significantly more often episodes (30%) compared to patients without a history of AF (11%; p < 0.001). In a multivariate model, only gender (p = 0.02) and history of AF (p < 0.001) were significantly associated predictors of the occurrence of appropriate ICD therapies during follow-up. Based on the propensity score model, the adjusted hazard ratio for male gender was 2.7 (p = 0.02) and 2.6 (p = 0.0004) for history of AF. CONCLUSION: Male gender and history of AF are independent predictors for the occurrence of sustained ventricular arrhythmia in primary ICD prophylaxis. Further studies need to evaluate whether history of AF in female patients might be an indicator for higher risk of sudden cardiac arrhythmic death.

Effects of cardiac resynchronisation therapy in patients with heart failure having a narrow QRS Complex enrolled in PROSPECT.

INTRODUCTION: Current guidelines recommend cardiac resynchronisation therapy (CRT) in patients with severe symptomatic heart failure, depressed left ventricular (LV) systolic function and a wide QRS complex (>or=120 ms). However, patients with heart failure having a narrow QRS complex might also benefit from CRT. DESIGN SETTING PATIENTS INTERVENTIONS: During the Predictors of Response to Cardiac Resynchronisation Therapy (PROSPECT) trial, 41 patients were enrolled in a 'narrow' QRS sub-study. These patients had a QRS complex <130 ms, but documented evidence of mechanical dyssynchrony by any of seven pre-defined echocardiographic measures. RESULTS: After 6 months of CRT, 26 (63.4%) patients showed improvement according to the Clinical Composite Score, 4 (9.8%) remained unchanged and 11 (26.8%) worsened. In patients with paired data, the 6-min walking distance increased from 334+/-118 m to 382+/-128 m, (p=0.003) and quality-of-life score improved from 44.2+/-19.7 to 26.8+/-20.2 (p<0.0001). Furthermore, there was a significant decrease in LV end-systolic diameter (from 59+/-9 to 55+/-12 mm, p=0.002) and in LV end-diastolic diameter (from 67+/-9 to 63+/-11 mm, p=0.007). CONCLUSION: The results suggest that CRT may have a beneficial effect in heart failure patients with a narrow QRS complex and mechanical dyssynchrony as assessed by echocardiography. The majority of patients improved on clinical symptoms, and there was an evident reduction in LV diameters. Larger studies are needed to clearly define selection criteria for CRT in patients with a narrow QRS complex.

Popping phenomena in temperature-controlled radiofrequency ablation: when and why do they occur?

During temperature-controlled radiofrequency (RF) ablation a popping sound sometimes occurs. This popping phenomenon is known to be associated with unwanted effects like blood boiling, endocardial rupture, catheter dislocation, and impedance rise. The present in vitro study determined the influence of cooling, electrode contact, and tip temperature on the occurrence of popping phenomena. Pieces of porcine ventricle were immersed in a bath of saline solution at 37 degrees C. Forty-two RF ablations were performed with different electrode-tissue contact forces (i.e., 0.0-0.44 N) in a temperature-controlled mode (70 degrees C setpoint, 30 s, 50 W maximum power output, 4-mm tip, thermocouple). Half of the 42 ablations were performed with fluid flow (0.1 m/s, group I), the other half without flow (group II). In group I, mean tip temperature and power were 55.6 +/- 8.5 degrees C and 36.2 +/- 13.8 W, resulting in a lesion volume of 121 +/- 57 mm3. In group II, the respective values were 67.3 +/- 1.5 degrees C and 9.9 +/- 5.2 W resulting in a volume of 42 +/- 18 mm3. The differences between groups were statistically significant. Overall, ten popping phenomena occurred in group I and none in group II. Pops occurred significantly more often when the contact force was < 0.1 N (8/10) and the tip temperature was < 60 degrees C (8/10). Two endocardial ruptures occurred, both were associated with a popping phenomenon. Using temperature control, the probability of pops is significantly higher when the ablation electrode and the endocardial tissue surface are exposed to fluid flow and the electrode-tissue contact is poor. Under these conditions the tissue temperature can be much higher than the temperature measured at the tip electrode and can potentially reach 100 degrees C causing intramyocardial steam formation and a popping phenomenon.