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Abstracts / Resuscita

P114

echanical ventilation during CPR: Influence of intermitted positive pressure venti-ation and BILEVEL ventilation on tidal volumes in a pig model

euhaus C. 1, Dietz F. 2, Hahn O. 3, Schwarz S. 3, Mahling R. 3, Wulf H. 3, Kill C. 3

Institut für Automatisierungstechnik und Qualitätssicherung e.V., Heidelberg, GermanyWeinmann Geräte für Medizin GmbH+Co.KG, Hamburg, GermanyDepartement of Anesthesiology and Critical Care, Philipps-University, Marburg, Germany

Objective: During CPR with secured airway, mechanical ventilation with an automatedentilator is recommend with a tidal volume of 6–7 ml/kg and a frequency of 10 breathser minute. We investigated the mechanical ventilation in a CPR pigmodel with an auto-ated ventilator using volume controlled intermitted positive pressure ventilation (IPPV)

r pressure controlled BILEVEL positive pressure ventilation (BILEVEL).Methods: After approval by local authorities 16 pigs underwent anaesthesia with

ndotracheal intubation. Ventricular fibrillation was induced followed by 3 min untreatedardiac arrest. Pigs were randomized to 10 min continuous chest compressions with eitherPPV (Tv 7 ml/kg, f = 10/min, 100% oxygen, no PEEP) or BILEVEL (pinsp 15–19 mbar tochieve a Tv of 7 ml/kg, f = 10/min, 100% oxygen, PEEP = 5 mbar) using an automated trans-ort ventilator “Medumat Transport” (Weinmann GmbH, Germany). After 10 min chestompressions with mechanical ventilation ALS was performed. The airflow was measurednd separated using digital high- and lowpass-filters. Tidal volumes were calculated fromhe first minute of CPR. Lowpass filtered signals represent mandatory ventilation, highpasshe passive ventilation caused by chest compressions.

Passive ventilation volumes were separately calculated during endexpiratory andndinspiratory cycle. Groups were compared using Mann–Whitney-U-Test.

Results: The flow data of 14 pigs (IPPV = 7, BILEVEL = 7) could be included.

Tidal volumepreset

Tidal volumemandatory

Tidal volumepassive(endexp.)

Tidal volumepassive(endinsp.)

IPPV [ml] 273 (282/253) 245 (265/207) 30 (47/18) 65 (114/56)BILEVEL [ml] 255 (266/249) 250 (326/201) 65 (98/60) 95 (113/79)p 0.702 0.035 0.160

Data shown as median (75/25 percentiles).Conclusions: IPPV and BILEVEL show similar mandatory volumes, that are consis-

ent with the preset values. Passive ventilation by chest compressions are low, BILEVELhows higher passive volumes than IPPV during expiration, probably due to the activatedowtrigger during PEEP-level.

oi:10.1016/j.resuscitation.2010.09.259

P115

ardiac life mechanical support in extrahospitalary donors after cardiac dead

ateos-Rodriguez, Navalpotro-Pascual J.M., Pardillos-Ferrer L., Martin-Maldonado

ME SUMMA112 Spain, Andres-Belmonte A Hospital 12 de Octubre Spain

Introduction: The Madrid Emergency Medical Service (SUMMA112) in collaborationith Madrid’s hospitals are employed at a program of donation of patients’ organs thatave suffered out-of-hospital cardiac arrest and no response of advanced life supportALS). The study’s aim is to assessment the use of mechanical cardio pump in this program.

Material and method: descriptive retrospective study based on the summary of infor-ation of the clinical records of all the cases in which the donor’s protocol has been

ctivated in asystole (Code O) during the year 2009.It use two mechanical cardio pump:utopulse – Zoll© and Lucas – Physio Control©.

Results: A total of 52 cases. 84.6% men and 15.4% women. The average’s age was 41ears (20–61). The average’s time of arrival to place of the intervention was 11 min and6 s. The average’s time of arrival to the hospital from the entry of the alarm call was9 min. There were obtained 100 organs (17 liver, 1 lungs, 56 kidneys, 10 bones and 16ye tissue), an average near 2 by patient. In 17.3% they were not valid donors. The reasonsf not donation were a failure extracorporeal pump in 1 cases, family denial in 5 cases,udge negative in 2 cases and biological reason in 2 of the cases (tumoral active pathology,ositive serology, etc.). Autopulse© was used in 20 cases and Lucas© in 30 cases. In twoases do not use anyone.

Conclusions: The use of these devices joins perfectly the non-heart beating donorsrocedure. The quality improves of the RCP and facilitates the work of the emergencyeam. It is necessary more studies to verify if his use increases the number of donatedrgans.

oi:10.1016/j.resuscitation.2010.09.260

1S (2010) S1–S114 S63

AP116

Compression velocity during CPR: Why automated CPR may perform better thanmanual CPR

Aelen P. 1, Paulussen I. 1, van Berkom P. 2, Venema A. 2, Noordergraaf G.J. 2, Woerlee P. 1

1 Biomedical Sensor Systems, Philips Research, Eindhoven, The Netherlands2 Dept of Anaesthesiology & Resuscitation, St. Elisabeth Hospital, Tilburg, The Netherlands

Introduction: Complete chest recoil may promote venous return to the heart, nec-essary for effective CPR.1 Fast, mechanical, retraction times have resulted in superiorhemodynamics in animal models when compared to manual sinusoidal compressionwaveforms.2 In this study the compression velocity of in-hospital manual CPR is quanti-fied and compared with the retraction velocity.

Methods: Compression and retraction velocity data from 74 patients were studied.Data was obtained with a Philips HeartStart MRX QCPR pad and were corrected for mat-tress effects.3 For comparison, compression and retraction velocity measurements wereperformed with three rescuers using a Resusci Anni manikin, with a weak [60 N/cm],medium [100 N/cm], stiff [150 N/cm] and a progressive spring load.

Results: Patients received compressions with a depth of 4.51 ± 0.87 cm. The com-pression and retraction velocities were 35 ± 8 cm/s and 26 ± 6 cm/s respectively, with thelatter being a factor 1.36 ± 0.31 smaller (p < 0.001). The manikin series showed similarcompression and retraction velocities for the linear loads (depth = 5.33 ± 0.77, compres-sion velocity = 45.0 ± 15.9 cm/s, retraction velocity = 45.0 ± 15.9 cm/s) but a significantdifference (p < 0.001) for the test with the progressive load (depth 5.56 ± 0.74, compres-sion velocity = 43.3 ± 9.1, retraction velocity = 32.1 ± 5.5).

Conclusion: The difference between compression and retraction velocity in manualCPR is related to the progressive distance-force relation of the human chest. With a patientresembling a non-linear load, the rescuer has to push harder in the deeper part of thecompression. This diminishes the ability to switch from compression to retraction quickly,and limits the retraction velocity. These findings suggest that mechanical automated CPRdevices may outperform manual CPR, as they can deliver retractions without limiting therecoil of the chest and thereby having increased time for venous return.

References

1. 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation andEmergency Cardiovascular Care. Circulation 2005;112(Suppl. I):IV1–203.

2. Tømte Ø, et al. Discriminating the effect of accelerated compression from acceler-ated decompression during high-impulse CPR in a porcine model of cardiac arrest.Resuscitation 2010;81:488–92.

3. Noordergraaf GJ, et al. The impact of compliant surfaces on in-hospital chest compres-sions: effects of common mattresses and a backboard. Resuscitation 2009;80:546–52.

doi:10.1016/j.resuscitation.2010.09.261

AP117

A single rescuer uses a manually powered mechanical assist device for resuscitation:A simulation study

Fischer H. 1, Neuhold S. 2, Zapletal B. 3, Karner P. 3, Maurer C. 3, Stumpf D. 3, Hochbrug-ger E. 4, Koinig H. 1, Greif R. 5

1 Department of Anaesthesia, General Intensive Care and Pain Control, Division of Cardio-thoracic and Vascular Anaesthesia and Intensive Care, Medical University Vienna, Vienna,Austria2 Department of Internal Medicine II, Division of Cardiology, Medical University Vienna,Vienna, Austria3 Medical University Vienna, Vienna, Austria4 Department of Internal Medicine III, Division of Endocrinology and Metabolism, MedicalUniversity Vienna, Vienna, Austria5 Department of Anaesthesiology and Pain Therapy, University Hospital Bern and Universityof Bern, Bern, Switzerland

Purpose of the study: The goal of this prospective, open, randomized crossovermanikin study was to compare the mechanical cardiopulmonary resuscitation (CPR)device “Animax”1 to standard single rescuer CPR.

Materials and methods: With ethics committee approval and informed consent, 80medical students trained in standard CPR and the mechanical CPR device performed basiclife support according to the European Resuscitation Council (ERC) guidelines 2005 for12-min in random order.2 Primary outcome parameter comparing efficacy and quality ofchest compressions was the number of effective compressions. An effective compressionwas defined as a compression with the correct depth of 4–5 cm, correct compression pointon the chest and sufficient decompression. This compound parameter adequately reflectseffective thorax compressions generating haemodynamically efficient circulation duringCPR. Furthermore, compression depth and rate, absolute hands-off time and ventilationparameters (minute volume, tidal volume and gastric inflations) were compared.

Results: The use of the mechanical CPR device resulted in a higher number of effec-tive compressions compared to standard CPR (58 ± 36% vs. 24 ± 29%, p < 0.001). With the

CPR device the absolute hands-off time was lower (79 ± 40 s vs. 264 ± 57 s, p < 0.001)and minute-volume was higher (1.9 ± 0.7 L vs. 1.6 ± 0.7 L, p < 0.02). However, ventilationvolumes achieved were below current ERC guidelines in both groups (370 ± 96 ml vs.421 ± 132 ml, p < 0.001). Gastric inflation occurred only once with the CPR device com-pared to 115 gastric inflations during standard CPR (p < 0.001).

Conclusion: Single rescuer CPR with the manually operated mechanical resuscitationdevice was superior to standard CPR on manikins. The CPR device delivered a higher