A Standardized Telephone Intervention Algorithm Improves the Survival of Ventricular Assist Device Outpatients.

Ventricular assist devices (VADs) are an established therapeutic option for patients with chronic heart failure. Continuous monitoring of VAD parameters and their adherence to guidelines are crucial to detect problems in an early stage to optimize outcomes. A telephone intervention algorithm for VAD outpatients was developed, clinically implemented and evaluated. During the phone calls, a structured inquiry of pump parameters, alarms, blood pressure, INR, body weight and temperature, exit-site status and heart failure symptoms was performed and electronically categorized by an algorithm into 5 levels of severity. VAD outpatient outcomes without (n = 71) and with bi-weekly telephone interviews in their usual care (n = 25) were conducted using proportional hazard Cox regression, with risk adjustment based on a propensity score model computed from demographics and risk factors. From February 2015 through October 2017, 25 patients (n = 3 HeartMate II, n = 4 HeartMate 3 and n = 18 HeartWare HVAD) underwent 637 telephone interventions. In 57.5% of the calls no problems were identified, 3.9% were recalled on the next day because of alarms. In 26.5% (n = 169), the VAD Coordinator had to refer to the physician due to elevated blood pressure (n = 125, >85 mm Hg), INR < 2.0 or > 4.0 (n = 24) or edema (n = 10), 11.9% of the calls led to a follow-up because of equipment or exit-site problems. Propensity-adjusted 2-year survival (89% vs. 57%, P = 0.027) was significantly higher for the telephone intervention group. Continuous, standardized communication with VAD outpatients is important for early detection of upcoming problems and leads to significantly improved survival.

Repair of left ventricular assist device driveline damage directly at the transcutaneous exit site.

With increasing support duration of cardiac assist devices, transcutaneous drivelines remain a weak point of the therapy. First, they can be an entry point for infections, and second, cable lesions and even electrical failures due to material fatigue and eventual carelessness can occur. We report a case of a damaged outer sheath of a ventricular assist device driveline cable directly at the exit site, where the standard repair procedure with self-fusing tape may lead to biocompatibility problems and irritation of the entrance through the skin. Therefore, a new procedure was developed using a special sleeve expander tool and a highly expandable latex tubing to stabilize the defect in a flexible and biocompatible manner. A patient experienced a fracture of the outer sheath of a HeartWare HVAD driveline directly at the skin entrance (approximately 15 mm long, 5 mm distal from the skin). The metal strands and the electrical functionality were yet not affected, therefore, a pump exchange was not indicated. After considering several conventional solutions for repair as not applicable, a new approach was developed: a sleeve expander tool was applied, which allowed radial stretching of the latex tubing. After preparations of the tool and the cable site, the pump was briefly disconnected, the tubing was moved over the connector and was released at the site of fracture. The problem could be solved by keeping the cable's flexibility and without additional risks to the skin. Within a still ongoing (5-month) follow-up, the skin entrance returned to perfect condition and no further intervention was necessary. In conclusion, this method allows a quick stabilization and repair of damaged driveline isolations even near the exit site, resulting in a biocompatible surface and consistent flexibility of the cable.

Importance of linguistic details in alarm messages of ventricular assist devices.

PURPOSE: In the daily use of ventricular assist devices (VAD), and especially in emergency situations, an easy, self-explanatory handling of the peripheral components is essential to solving life-threatening situations, for non-experienced bystanders as well as professional staff members. It has been proven that displaying messages can significantly improve proper reactions. However, in the case we report, an accidental pump cable disconnection could not be solved without the assistance of the VAD coordinator.
 CASE REPORT: A long-term HeartWare® HVAD patient inadvertently disconnected himself from the pump, most probably due to a metabolically caused mental disorder, for which he had been readmitted to the hospital. Unluckily, the pump cable slipped beneath the bed sheet and the ward staff was not able to solve the problem. The staff who were involved claimed that the messages on the controller did not help them to resolve the difficulty. A comparison between the German and English texts revealed some ambivalence in the German wordings. 
 RESULTS: Laypersons were asked to respond to this situation in a simulated scenario, starting with the original alarm messages "VAD stopped"-"VAD gestoppt" and "Connect Driveline"-"Verb-Kabel anschl." If they were unable to solve the problem within 3 minutes, another translation was offered orally: "Pumpe steht" and "Pumpenkabel anschließen". None of the 5 test persons were able to respond correctly to the emergency situation with the original translation, but when provided with a modified translation, everybody solved the problem within 30 seconds.
 CONCLUSIONS: Even small linguistic differences can lead to critical differences in the usability and, thus, the safety of VAD peripherals. Detailed discussions with professional translators and/or practical tests of failure scenarios may optimize usability.

Rapid induction of mild therapeutic hypothermia by extracorporeal veno-venous blood cooling in humans.

AIM: Mild therapeutic hypothermia is beneficial in patients successfully resuscitated from non-traumatic out-of-hospital cardiac arrest. The effect of fast induction of hypothermia in these patients remains to be investigated. The aim of this study was to evaluate the efficacy and safety of extracorporeal veno-venous blood cooling in humans successfully resuscitated from cardiac arrest. METHODS: We performed an interventional study in patients after successful resuscitation from cardiac arrest admitted to the emergency department of a tertiary care centre. The extracorporeal veno-venous circulation was established via a percutaneously introduced double lumen dialysis catheter in the femoral vein, and a tubing circuit and heat exchanger. A paediatric cardiopulmonary bypass roller pump and a heater-cooler system were used to circulate the blood. Main outcome measures were feasibility, efficacy, and safety. RESULTS: We included eight consecutive cardiac arrest patients with a median oesophageal temperature of 35.9°C (interquartile range 34.9-37.0). A median time of 8 min elapsed (interquartile range 5-15 min) to reach oesophageal temperatures below 34°C, which reflects a cooling rate of 12.2°C/h (interquartile range 10.8°C/h to 14.1°C/h). The predefined target temperature of 33.0°C was reached after 14 min (interquartile range 8-21 min). No device or method related adverse events were reported. CONCLUSION: Extracorporeal veno-venous blood cooling is a feasible, safe, and very fast approach for induction of mild therapeutic hypothermia in patients successfully resuscitated from cardiac arrest.