Jean Micheels

Safety of fully automatic external defibrillation by untrained lay rescuers in the presence of a bystander

OBJECTIVE Automated external defibrillators (AEDs) are becoming increasingly available in public places to be used by citizens in case of cardiac arrest. Most AEDs are semi-automatic (SAEDs), but some are fully automatic (FAEDs) and there is ongoing debate and concern that they may lead to inadvertent shocks to rescuers or bystanders because the timing of the shock is not controlled by the rescuer. We therefore compared the behaviour of untrained citizens using an FAED or an SAED in a simulated cardiac arrest scenario. DESIGN AND PARTICIPANTS One hundred and seventy-six laypeople were randomised to use an FAED or an SAED (Lifepak CR+, Medtronic, Redmond, USA) in a simulated cardiac arrest scenario on a manikin (Ambu, Denmark) where a bystander was touching the victims upper arm. Each rescuers performance was recorded on video and analysed afterwards using a modified Cardiff Score. The rescuer or the bystander was considered unsafe if either of them touched the victim during shock delivery. RESULTS Eleven cases could not be analysed because of technical problems. Fifteen participants violated the protocol making further analysis impossible. Of the remaining 150 participants, 68 used the FAED and 82 used the SAED. The rescuers were safe in 97/150 (65%) cases, without a difference between FAED and SAED. The bystander was safe in 25/68 (37%) cases in the FAED group versus 19/82 (23%) in the SAED group (p=0.07). Combined safety of both rescuer and bystander was observed in 23/68 (34%) cases in the FAED group versus 15/82 (18%) in the SAED group (p=0.03). CONCLUSIONS Safety was not compromised when untrained lay rescuers used an FAED compared with an SAED. The observation of overall safer behaviour by FAED users in the presence of bystanders may be related to the additional instructions provided by the FAED, and the reduced interaction of the rescuer with the bystander when using the SAED.

Biochemical investigations after burning injury: Complement system, protease-antiprotease balance and acute-phase reactants

Seventeen burned patients were investigated--Group I (n=10) with a mean burned area expressed as unit burn standard (UBS) of 69 +/- 24 and Group II (n = 7) with a mean UBS of 23 +/- 8. Blood samples were collected immediately after admission, 6-12 h after injury, during the morning and evening of day 1, and then daily for 2 weeks. This prospective study demonstrated complement activation in vivo in all burned patients, measured by C3d/C3 ratio index which was not related to the extent of the burned surface. A significant protease-antiprotease imbalance, correlated to the severity of burns, was found, leukocyte elastase was increased throughout the observation period, alpha 2-macroglobulin drastically decreased in severely burned patients, and alpha 1-proteinase inhibitor promptly decreased below the normal level in patients with more than 40 UBS. Finally, there was a delayed but then persistent acute-phase reactant protein response involving C-reactive protein, haptoglobin and alpha 1-acid glycoprotein, the concentrations of which reached a plateau on days 6 or 7.

Biochemical Mediators in Acute Respiratory Distress Syndrome (ARDS) after Burning Injury

Seventeen burned patients, 5 of whom developed the adult respiratory distress syndrome (ARDS), were investigated. Occurrence of ARDS was correlated with the severity of burn in ARDS patients (UBS: 82±27) and non ARDS patients (UBS: 36 ± 18) respectively (p < 0.005) and with inhalation injury.