Does an individualized feedback mechanism improve quality of out-of-hospital CPR?

BACKGROUND: Despite its prevalence, survival from out-of-hospital cardiac arrest remains low. High quality CPR has been associated with improved survival in cardiac arrest patients. In early 2014, a program was initiated to provide feedback on CPR quality to prehospital providers after every treated cardiac arrest. OBJECTIVE: To assess whether individualized CPR feedback was associated with improved CPR quality measures in the prehospital setting. METHODS: This before and after retrospective review included all treated adult out-of-hospital cardiac arrest in patients in an urban community. Data was compared prior to and after the initiation of the CPR feedback program. We compared the percent of encounters reaching the system defined benchmarks as well as the average values for compression fraction, compression rate, compression depth, and pre-shock pause in the before period compared to the after period. RESULTS: There were 159 encounters in the before period and 117 in the after. Compared to the before group, the after group had higher average compression rates (111.2/min vs 113.8/min; p=0.042), increased compression depths (4.9cm vs 5.6cm; p<0.001), and increased rates of benchmark achievement for compression depth greater than 5cm (48.1% vs 72.6%; p<0.001). No significant difference was noted in pre-shock pause (21.4s vs 14.7s; p=0.068). Additionally, no difference was noted between groups for compression fraction, though goal achievement was high in both groups. CONCLUSION: We found that individual CPR feedback is associated with marginally improved quality of CPR in the prehospital setting. Further investigation with larger samples is warranted to better quantify this effect.

Expression, purification, crystallization and preliminary X-ray diffraction studies of recombinant class B non-specific acid phosphatase of Salmonella typhimurium.

The aphA gene of Salmonella enterica sv. Typhimurium strain MD6001 was cloned in the multicopy plasmid pBluescript SK(-). The recombinant AphA protein was purified to homogeneity. The protein crystallized in the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 112.4, b = 130.2, c = 139.6 A. Consistent with the self-rotation function, there are two tetramers in the asymmetric unit, indicating a solvent content of approximately 54%. The crystals are composed of biologically active AphA molecules.

Regulation of catalytic function by molecular association: structure of phospholipase A2 from Daboia russelli pulchella (DPLA2) at 1.9 A resolution.

The crystal structure of phospholipase A(2) from the venom of Daboia russelli pulchella has been refined to an R factor of 0.216 using 17,922 reflections to 1.9 A resolution. The structure contains two crystallographically independent molecules in the asymmetric unit. The overall conformations of the two molecules are essentially the same except for three regions, namely the calcium-binding loop including Trp31, the beta-wing and the C-terminal residues 119-131. Although these differences have apparently been caused by molecular packing, they seem to have functional relevance. Particularly noteworthy is the conformation of Trp31, which is favourable for substrate binding in one molecule as it is aligned with one of the side walls of the hydrophobic channel, whereas in the other molecule it is located at the mouth of the channel, thereby blocking the entry of substrates leading to loss of activity. This feature is unique to the present structure and does not occur in the dimers and trimers of other PLA(2)s.