Technical performance and reflection capacity of the anaesthetic conserving device--a bench study with isoflurane and sevoflurane.

OBJECTIVE: The anaesthetic conserving device (AnaConDa), Sedana Medical, Sundbyberg, Sweden) facilitates administration of isoflurane or sevoflurane by liquid infusion. An anaesthetic reflector inside the device conserves exhaled anaesthetic and re-supplies it during inspiration. In this bench study, we examined the influence of infusion rates and ventilatory settings on the resulting anaesthetic concentrations on patient (C(pat)) and ventilator side of the reflector (C(loss)) to describe its technical performance. METHODS: A Puritan Bennett 840 ICU ventilator (Pleasanton, US), AnaConDa, and a test lung (3 l-chloroprene-bag) were assembled. Infusion rates (IR, 0.2-50 ml h(-1)), respiratory rates (RR, 5-40 breaths min(-1)), and tidal volumes (V(T), 0.3, 0.5, and 1.0 l) were varied. C(pat) was measured via a thin catheter in the middle of the 3 l-bag in steady state (online data storage and averaging over >10 min). C(loss) was calculated from IR (to yield the volume of vapour per unit of time), and expired minute volume (in which the vapour is diluted) on the assumption that, in the steady state, input by liquid infusion equals output through the reflector. RESULTS: At lower concentrations (C(pat) < 1 vol%) the ratio C(loss)/C(pat) was constant (R(C) = 0.096 +/- 0.012) for all combinations of IR, RR and V(T), both for isoflurane and sevoflurane. The device could efficiently reflect up to 10 ml vapour per breath (e.g. 2 vol% in 0.5 l). When exceeding this capacity, surplus vapour "spilled over" and R(C) markedly increased indicating decreased performance. CONCLUSIONS: The triple product minute volume times R(C) times C(pat) describes anaesthetic losses through the reflector. It can easily be calculated as long as the 10 ml reflection capacity is not exceeded and thus R(C) is constant. Increased minute ventilation necessitates increasing the IR to keep C(pat) constant. When using large V(T) and high C(pat) "spill over" occurs. This effect offers some protection against an inadvertent overdose.

Hospital-wide first-responder automated external defibrillator programme: 1 year experience.

The first year experience with a hospital-wide first-responder automated external defibrillator (AED) programme implemented in a 683-bed University Hospital is reported. Throughout the hospital, 14 "AED access spots" were identified which could be easily reached from all wards and diagnostic rooms within 30s. AEDs were installed (Lifepak 500; Medtronik PhysioControl Corp., Redmond, USA, equipped with a Biolog 3000i portable ECG monitor; Micromedical Industries Ltd., Labrador, Australia). Within 3 months, 120 medical officers, 750 nurses, and 50 administrative or technical staff underwent a 2h training programme. An AED was applied and activated by nurses/medical staff before the cardiac arrest team arrived in 27 of 33 cases (81.8%) of witnessed cardiac arrest. The median time from onset of the emergency call to the activation of the AED (record of ECG) was on average 2.1 min (range 1.0--4.5 min). In 18 of 27 cases in which the AED was installed promptly, the primary arrest rhythm was either VT or VF, and the AED delivered a shock. For this subgroup, the rate of return of spontaneous circulation and the rate of discharge at home were 88.9 and 55.6%, respectively. This encourages us to extend the concept of first-responder AED-defibrillation throughout our hospital.

Prehospital therapy with the platelet glycoprotein IIb/IIIa inhibitor eptifibatide in patients with suspected acute coronary syndromes: the Bochum feasibility study.

STUDY OBJECTIVES: To assess the practical application and safety of prehospital antithrombotic therapy with the glycoprotein (GP) IIb/IIIa inhibitor eptifibatide for patients with suspected acute coronary syndrome (ACS) or myocardial infarction (MI). DESIGN: Open-labeled pilot study. Patients with typical chest pain who were seen within 6 h of the onset of symptoms were enrolled in the mobile emergency ambulance. Patients were stratified by even/uneven days to receive standard treatment or standard treatment plus an IV bolus of eptifibatide (180 microg/kg body weight) followed by a continuous eptifibatide infusion (2 microg/kg/min). The main outcome measurement was a combination of prehospital or in-hospital death, reinfarction, revascularization of target vessels, and major bleeding complications. RESULTS: A total of 356 patients (age range, 29 to 75 years; women, 24.7%) were included in the analysis. On admission to the hospital, the diagnosis of ACS or MI was confirmed in approximately 60% of patients, and alternative diagnoses were made in 40% of patients. The rates of complications, including fatal and nonfatal complications occurring during transportation and during subsequent hospitalization, were similar in both study groups. The primary end point occurred in 11.8% of patients in the control group, and in 9.6% of those in the eptifibatide group (difference not significant). CONCLUSION: The prehospital administration of the GP IIb/IIIa inhibitor eptifibatide is feasible and safe in patients with clinically suspected ACS and MI. The benefit of this treatment has yet to be established in a large-scale multicenter study.