[Patients with implanted ventricular assist devices : Challenge for emergency medicine]. / Patienten mit implantierten Herzunterstützungssystemen : Herausforderung in der Notfallmedizin.

Due to a huge increase in the implantation of ventricular assist devices (VAD) over the last few years and the enormous technical advances in functional safety, a growing number of patients with VAD are discharged from hospital, who are still considered to be severely ill. This results in an increased probability of these patients interacting with emergency services where personnel are unaware of the presence of a VAD, creating anxiety and uncertainty regarding how to treat these patients. This article presents an overview of the most common problems and pitfalls regarding VADs. It also presents an algorithm for dealing with emergencies involving these patients including the diagnostics, treatment and primary transport.

Reliability of different body temperature measurement sites during aortic surgery.

OBJECTIVE: We retrospectively performed a comparative analysis of temperature measurement sites during surgical repair of the thoracic aorta. METHODS: Between January 2004 and May 2006, 22 patients (mean age: 63 ± 12 years) underwent operations on the thoracic aorta with arterial cannulation of the aortic arch concavity and selective antegrade cerebral perfusion (ACP) during deep hypothermic circulatory arrest (HCA). Indications for surgical intervention were acute type A dissection in 14 (64%) patients, degenerative aneurysm in 6 (27%), aortic infiltration of thymic carcinoma in 1 (4.5%) and intra-aortic stent refixation in 1 (4.5%). Rectal, tympanic and bladder temperatures were evaluated to identify the best reference to arterial blood temperature during HCA and ACP. RESULTS: There were no operative deaths and the 30-day mortality rate was 13% (three patients). Permanent neurological deficits were not observed and transient changes occurred in two patients (9%). During re-warming, there was strong correlation between tympanic and arterial blood temperatures (r = 0.9541, p<0.001), in contrast to the rectal and bladder temperature (r = 0.7654, p = n.s; r = 0.7939, p = n.s., respectively). CONCLUSION: We conclude that tympanic temperature measurements correlate with arterial blood temperature monitoring during aortic surgery with HCA and ACP and, therefore, should replace bladder and rectal measurements.

First experience with the new portable extracorporeal membrane oxygenation system Cardiohelp for severe respiratory failure in adults.

BACKGROUND: Over the last decade, technical improvements in extracorporeal membrane oxygenation (ECMO) equipment have reduced procedure-related complications and have made ECMO an effective option for patients with acute respiratory distress syndrome (ARDS) if conventional therapy fails. METHODS: In this report, we present our early experience with the Cardiohelp, a new portable miniaturized ECMO system, in 22 consecutive patients with ARDS. All patients were placed on venovenous ECMO. Cannulas were inserted percutaneously, employing the Seldinger technique. Data were collected prospectively. RESULTS: The median patient age was 47 years (36 to 61). Fifteen patients from regional hospitals were too unstable for conventional transport and were placed on Cardiohelp at the referring hospital and then transported to our institution. The patients were transported by ambulance (n=2) or helicopter (n=13) over a distance of 50-250 km. Cardiohelp support resulted in immediate improvement of gas exchange and highly protective ventilation. The median duration of support was 13 days (8 to 19). An exchange of the device was necessary in 9 patients. Sixteen patients (72.7%) were successfully weaned from ECMO and fifteen patients (68.2%) survived. Device-related complications were not observed. CONCLUSIONS: The compact portable ECMO device Cardiohelp is a highly effective method to secure vital gas exchange and to reduce further ventilator-induced lung injury in patients with acute respiratory failure. Crucial technical innovations and ease of device transport and implantation allow location-independent stabilization with consecutive inter-hospital transfer.

Interhospital transportation of patients with severe lung failure on pumpless extracorporeal lung assist.

BACKGROUND: To describe the use of pumpless extracorporeal interventional lung assist (iLA) for transportation of patients with severe life-threatening acute lung failure from tertiary hospitals to a specialized centre. METHODS: Retrospective analysis in eight patients with severe lung failure requiring interhospital transport, in whom implementation of an iLA system at a tertiary hospital for air/ground transportation was performed. RESULTS: After implementation of iLA, a rapid increase in CO2-elimination (Pa(CO2) before iLA: 8.92+/-2.9 kPa, immediately after implementation: 5.06+/-0.93 kPa, 24 h after implementation: 4.53+/-1.20 kPa [mean+/-SD], P<0.05) was observed and a significant improvement in oxygenation (Pa(O2) before iLA: 6.66+/-2.26 kPa, immediately after implementation: 10.39+/-3.33 kPa, 24 h after implementation: 10.25+/-5.46 kPa, P<0.05) was noted. During transport, no severe complications occurred. Four patients died during further treatment due to multiple trauma or multiple organ failure. CONCLUSIONS: Due to ease of handling, high effectiveness and relatively low costs, iLA seems to be a useful system for treatment and transportation of patients with severe acute lung injury or ARDS suffering from life-threatening hypoxia and/or hypercapnia.

Adequacy of perfusion during hypothermia: regional distribution of cardiopulmonary bypass flow, mixed venous and regional venous oxygen saturation - hypothermia and distribution of flow and oxygen.

BACKGROUND: Hypothermia during CPB is used to reduce metabolic activity, thus protecting organs and tissues. The aim of this study was to investigate the relationship between regional and mixed venous oxygen saturation and distribution of pump flow with respect to hypothermia. METHODS: Twenty-five patients undergoing a Ross procedure were included in a prospective, controlled study. During standard CPB, temperature was reduced stepwise to 28 degrees C. Blood gases (a-stat regimen) were analysed in samples from the inferior (IVC) and the superior vena cava (SVC), arterial and mixed venous blood. Flow was detected separately in the SVC, IVC, arterial, and collecting venous line. Samples were taken, and flows were measured before CPB, during hypothermia, during rewarming, and 30 min after CPB discontinuation. RESULTS: Oxygen saturation in the IVC was lower than in the SVC and in mixed venous blood at all times (max. difference - 17.3 +/- 3.0 % during hypothermia, - 23.8 +/- 2.9 % during rewarming, p < 0.01). There was a statistical correlation of mixed and IVC venous oxygen saturation (r = 0.79, p < 0.001) but not of SVC venous blood. Hypothermia had a major influence on pump flow distribution as backflow from the SVC decreased significantly in favour of IVC flow with increasing degree of hypothermia (increase of flow difference from 1.15 +/- 0.23 l/min to 1.49 +/- 0.36 l/min, p < 0.01). Temperature profiles were similar when detected in aorta, pulmonary artery, tympanum and nasopharygeum, but differed significantly from other sites. CONCLUSIONS: During hypothermic CPB, regional deoxygenation occurs in spite of normal mixed venous saturation. The level of hypothermia has a major impact on bypass flow distribution with cerebral perfusion reduction. Methods of regional oxygenation assessment are needed, and altered strategies during hypothermia have to be taken into consideration.