Oslo government district bombing and Utøya island shooting July 22, 2011: the immediate prehospital emergency medical service response.

BACKGROUND: On July 22, 2011, a single perpetrator killed 77 people in a car bomb attack and a shooting spree incident in Norway. This article describes the emergency medical service (EMS) response elicited by the two incidents. METHODS: A retrospective and observational study was conducted based on data from the EMS systems involved and the public domain. The study was approved by the Data Protection Official and was defined as a quality improvement project. RESULTS: We describe the timeline and logistics of the EMS response, focusing on alarm, dispatch, initial response, triage and evacuation. The scenes in the Oslo government district and at Utøya island are described separately. CONCLUSIONS: Many EMS units were activated and effectively used despite the occurrence of two geographically separate incidents within a short time frame. Important lessons were learned regarding triage and evacuation, patient flow and communication, the use of and need for emergency equipment and the coordination of helicopter EMS.

Mechanical chest compressions with trapezoidal waveform improve haemodynamics during cardiac arrest.

BACKGROUND: During manual chest compressions for cardiac arrest the waveforms of chest compressions are generally sinusoidal, whereas mechanical chest compression devices can have different waveforms, including trapezoidal. We studied the haemodynamic differences of such waveforms in a porcine model of cardiac arrest. METHODS: Eight domestic pigs (weight 31±3kg) were anaesthetised and instrumented to continuously monitor aortic (AP) and right atrial pressure (RAP), carotid (CF) and cerebral cortical microcirculation blood flow (CCF). Coronary perfusion pressure (CPP) was calculated as the maximal difference between AP and RAP during diastole or decompression phase. After 4 min of electrically induced ventricular fibrillation, mechanical chest compressions were performed with four different waveforms in a factorial design, and in randomized sequence for 3 min each. Resulting differences are presented as mean with 95% confidence intervals. RESULTS: Mean AP and RAP were higher with trapezoid than sinusoid chest compressions, difference 5.7 (0.7, 11) and 6.3 (2.1, 11)mmHg, respectively. Flow measured as CF and CCF was also improved with trapezoidal waveform, difference 14 (2.8, 26)ml/min and 11 (5.6, 17)% of baseline, respectively, with a parallel, non-significant (P=0.08) trend for CPP. Active vs. passive decompression to zero level improved CF, but without even a trend for CPP. CONCLUSION: Trapezoid chest compressions and active decompression to zero level improved blood flow to the brain. The compression waveform is an additional factor to consider when comparing mechanical and manual chest compressions and when comparing different compression devices.

Transthoracic impedance changes as a tool to detect malpositioned tracheal tubes.

BACKGROUND: Undetected malpositioned or dislodged ventilation tubes during cardiac arrest have fatal consequences, and no single method can detect the tube position reliably during such low-flow states. We wanted to test the ability of impedance changes as measured across the chest via the standard defibrillation pads to distinguish between oesophageal and tracheal ventilations in non-circulated patients. MATERIALS AND METHODS: After the end of futile resuscitation transthoracic impedance was measured with a prototype defibrillator, and ventilation variables were collected with a spirometer-capnography unit during tracheal ventilations and after repositioning of the tube; during oesophageal ventilations for paired comparisons. RESULTS: We registered 123 oesophageal and 178 tracheal ventilations in nine patients. Transthoracic impedance changes associated with ventilations were always larger during tracheal than oesophageal ventilations (mean difference 1.3 ohms (95% CI 1.0, 1.5), P<0.001), and all such changes above 1.2 ohms were associated with tracheal ventilations, while changes below 0.4 ohms always were associated with oesophageal ventilations. By subtracting 0.5 ohms from the individual mean transthoracic change associated with tracheal ventilations, tube position was predicted with sensitivity 0.99 and specificity 0.97. CONCLUSION: Transthoracic impedance changes may be used to detect malpositioned and dislodged tubes also during situations without spontaneous circulation. Our predictive values must be retested in another population.

A failed attempt to improve quality of out-of-hospital CPR through performance evaluation.

INTRODUCTION: Quality of CPR performed by professionals has been reported to be substandard even with automated corrective feedback. Our hypothesis was that providing CPR performance evaluation (CPR-PE) to three ambulance services would facilitate local education and implementation of CPR guidelines and, consequently, improve CPR quality. METHODS: Quality of CPR in 85 consecutive cases of adult out-of-hospital cardiac arrests after CPR-PE was compared to 39 cases prior to CPR-PE. Real-time automated verbal and visual feedback on CPR performance was given in all cases. No general implementation strategy was provided because the sites were expected to use the CPR-PEs in development of local strategies. Because the strategies were expected to vary, the sites were analyzed separately. RESULTS: No significant improvement was seen in quality of CPR after CPR-PE. No chest compressions were given 40% of the time before versus 41% after CPR-PE. The median (95% confidence interval) percentage of chest compressions within the recommended depth range (38-51 mm) was 35% (27-57) before versus 51% (42-60) after CPR-PE (p = 0.12). In site-specific analysis, chest compressions within guideline depth increased from 31% to 61% after CPR-PE (p = 0.05) in one site. CONCLUSIONS: Overall our attempt to improve CPR-quality was unsuccessful. Quality improvement likely requires a full range of implementation strategies to change current attitudes and practices.