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Berve PO, Irusta U, Kramer-Johansen J, Skålhegg T, Aramendi E, Wik L. Tidal volume measurements via transthoracic impedance waveform characteristics: The effect of age, body mass index and gender. A single centre interventional study. Resuscitation 2021; 167:218-224. [PMID: 34480974 DOI: 10.1016/j.resuscitation.2021.08.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND AIM Measuring tidal volumes (TV) during bag-valve ventilation is challenging in the clinical setting. The ventilation waveform amplitude of the transthoracic impedance (TTI-amplitude) correlates well with TV for an individual, but poorer between patients. We hypothesized that TV to TTI-amplitude relations could be improved when adjusted for morphometric variables like body mass index (BMI), gender or age, and that TTI-amplitude cut-offs for ventilations with adequate TV (>400ml) could be established. MATERIALS AND METHODS Twenty-one consenting adults (9 female, and 9 overall overweight) during positive pressure ventilation in anaesthesia before scheduled surgery were included. Seventeen ventilator modes were used (⩾ five breaths per mode) to adjust different TVs (150-800 ml), ventilation frequencies (10-30 min-1) and insufflation times (0.5-3.5 s). TTI from the defibrillation pads was filtered to obtain ventilation TTI-amplitudes. Linear regression models were fitted between target and explanatory variables, and compared (coefficient of determination, R2). RESULTS The TV to TTI-amplitude slope was 1.39 Ω/l (R2=0.52), with significant differences (p<0.05) between male/female (1.04 Ω/l vs 1.84 Ω/l) and normal/overweight subjects (1.65 Ω/l vs 1.04 Ω/l). The median (interquartile range) TTI-amplitude cut-off for adequate TV was 0.51 Ω(0.14-1.20) with significant differences between males and females (0.58 Ω/0.39 Ω), and normal and overweight subjects (0.52 Ω/0.46 Ω). The TV to TTI-amplitude model improved (R2=0.66) when BMI, age and gender were included. CONCLUSIONS TTI-amplitude to TV relations were established and cut-offs for ventilations with adequate TV determined. Patient morphometric variables related to gender, age and BMI explain part of the variability in the measurements.
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Affiliation(s)
- P O Berve
- Norwegian National Advisory Unit for Prehospital Emergency Medicine (NAKOS), Oslo University Hospital - Ullevål and University of Oslo, Po Box 4956 Nydalen, N-0424 Oslo, Norway; Air Ambulance Department, Division of Prehospital Services, Oslo University Hospital, Oslo, Norway.
| | - U Irusta
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain; Biocruces Bizkaia Health Research Institute, Cruces Plaza, 48903 Barakaldo, Bizkaia, Spain
| | - J Kramer-Johansen
- Norwegian National Advisory Unit for Prehospital Emergency Medicine (NAKOS), Oslo University Hospital - Ullevål and University of Oslo, Po Box 4956 Nydalen, N-0424 Oslo, Norway; Air Ambulance Department, Division of Prehospital Services, Oslo University Hospital, Oslo, Norway
| | - T Skålhegg
- Air Ambulance Department, Division of Prehospital Services, Oslo University Hospital, Oslo, Norway; Ambulance Department, Division of Prehospital Services, Oslo University Hospital, Oslo, Norway
| | - E Aramendi
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain; Biocruces Bizkaia Health Research Institute, Cruces Plaza, 48903 Barakaldo, Bizkaia, Spain
| | - L Wik
- Norwegian National Advisory Unit for Prehospital Emergency Medicine (NAKOS), Oslo University Hospital - Ullevål and University of Oslo, Po Box 4956 Nydalen, N-0424 Oslo, Norway; Air Ambulance Department, Division of Prehospital Services, Oslo University Hospital, Oslo, Norway
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Skåre C, Calisch TE, Saeter E, Rajka T, Boldingh AM, Nakstad B, Niles DE, Kramer-Johansen J, Olasveengen TM. Implementation and effectiveness of a video-based debriefing programme for neonatal resuscitation. Acta Anaesthesiol Scand 2018; 62:394-403. [PMID: 29315458 DOI: 10.1111/aas.13050] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/02/2017] [Accepted: 11/24/2017] [Indexed: 01/03/2023]
Abstract
BACKGROUND Approximately 5%-10% of newly born babies need intervention to assist transition from intra- to extrauterine life. All providers in the delivery ward are trained in neonatal resuscitation, but without clinical experience or exposure, training competency is transient with a decline in skills within a few months. The aim of this study was to evaluate whether neonatal resuscitations skills and team performance would improve after implementation of video-assisted, performance-focused debriefings. METHODS We installed motion-activated video cameras in every resuscitation bay capturing consecutive compromised neonates. The videos were used in debriefings led by two experienced facilitators, focusing on guideline adherence and non-technical skills. A modification of Neonatal Resuscitation Performance Evaluation (NRPE) was used to score team performance and procedural skills during a 7 month study period (2.5, 2.5 and 2 months pre-, peri- and post-implementation) (median score with 95% confidence interval). RESULTS We compared 74 resuscitation events pre-implementation to 45 events post-implementation. NRPE-score improved from 77% (75, 81) to 89% (86, 93), P < 0.001. Specifically, the sub-categories "group function/communication", "preparation and initial steps", and "positive pressure ventilation" improved (P < 0.005). Adequate positive pressure ventilation improved from 43% to 64% (P = 0.03), and pauses during initial ventilation decreased from 20% to 0% (P = 0.02). Proportion of infants with heart rate > 100 bpm at 2 min improved from 71% pre- vs. 82% (P = 0.22) post-implementation. CONCLUSION Implementation of video-assisted, performance-focused debriefings improved adherence to best practice guidelines for neonatal resuscitation skill and team performance.
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Affiliation(s)
- C. Skåre
- Norwegian National Advisory Unit for Prehospital Emergency Care (NAKOS); Department of Anaesthesiology; Oslo University Hospital; University of Oslo; Oslo Norway
| | - T. E. Calisch
- Neonatal Intensive Care Unit; Oslo University Hospital; Oslo Norway
| | - E. Saeter
- Department of Anaesthesiology; Oslo University Hospital; Oslo Norway
| | - T. Rajka
- Paediatric Intensive Care Unit; Oslo University Hospital; Oslo Norway
| | - A. M. Boldingh
- Department of Paediatric and Adolescent Medicine and Institute of Clinical Medicine; University of Oslo; Akershus University Hospital; Lørenskog Norway
| | - B. Nakstad
- Department of Paediatric and Adolescent Medicine and Institute of Clinical Medicine; University of Oslo; Akershus University Hospital; Lørenskog Norway
| | - D. E. Niles
- Center for Simulation; Advanced Education and Innovation; The Children`s Hospital in Philadelphia; Philadelphia PA USA
| | - J. Kramer-Johansen
- Norwegian National Advisory Unit for Prehospital Emergency Care (NAKOS); Department of Anaesthesiology; Oslo University Hospital; University of Oslo; Oslo Norway
| | - T. M. Olasveengen
- Norwegian National Advisory Unit for Prehospital Emergency Care (NAKOS); Department of Anaesthesiology; Oslo University Hospital; Oslo Norway
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Ringh M, Hollenberg J, Palsgaard-Moeller T, Svensson L, Rosenqvist M, Lippert FK, Wissenberg M, Malta Hansen C, Claesson A, Viereck S, Zijlstra JA, Koster RW, Herlitz J, Blom MT, Kramer-Johansen J, Tan HL, Beesems SG, Hulleman M, Olasveengen TM, Folke F. The challenges and possibilities of public access defibrillation. J Intern Med 2018; 283:238-256. [PMID: 29331055 DOI: 10.1111/joim.12730] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Out-of-hospital cardiac arrest (OHCA) is a major health problem that affects approximately four hundred and thousand patients annually in the United States alone. It is a major challenge for the emergency medical system as decreased survival rates are directly proportional to the time delay from collapse to defibrillation. Historically, defibrillation has only been performed by physicians and in-hospital. With the development of automated external defibrillators (AEDs), rapid defibrillation by nonmedical professionals and subsequently by trained or untrained lay bystanders has become possible. Much hope has been put to the concept of Public Access Defibrillation with a massive dissemination of public available AEDs throughout most Western countries. Accordingly, current guidelines recommend that AEDs should be deployed in places with a high likelihood of OHCA. Despite these efforts, AED use is in most settings anecdotal with little effect on overall OHCA survival. The major reasons for low use of public AEDs are that most OHCAs take place outside high incidence sites of cardiac arrest and that most OHCAs take place in residential settings, currently defined as not suitable for Public Access Defibrillation. However, the use of new technology for identification and recruitment of lay bystanders and nearby AEDs to the scene of the cardiac arrest as well as new methods for strategic AED placement redefines and challenges the current concept and definitions of Public Access Defibrillation. Existing evidence of Public Access Defibrillation and knowledge gaps and future directions to improve outcomes for OHCA are discussed. In addition, a new definition of the different levels of Public Access Defibrillation is offered as well as new strategies for increasing AED use in the society.
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Affiliation(s)
- M Ringh
- Department for Medicine, Center for Resuscitation Science, Karolinska Institutet, Stockholm, Sweden
| | - J Hollenberg
- Department for Medicine, Center for Resuscitation Science, Karolinska Institutet, Stockholm, Sweden
| | - T Palsgaard-Moeller
- Emergency Medical Services Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - L Svensson
- Department for Medicine, Center for Resuscitation Science, Karolinska Institutet, Stockholm, Sweden
| | - M Rosenqvist
- Department of Clinical Sciences, Danderyd University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - F K Lippert
- Emergency Medical Services Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - M Wissenberg
- Emergency Medical Services Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - C Malta Hansen
- Emergency Medical Services Copenhagen, University of Copenhagen, Copenhagen, Denmark.,Department of Cardiology, Copenhagen University Hospital Gentofte, Hellerup, Denmark
| | - A Claesson
- Department for Medicine, Center for Resuscitation Science, Karolinska Institutet, Stockholm, Sweden
| | - S Viereck
- Emergency Medical Services Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - J A Zijlstra
- Department of Cardiology, Heart Center, Academic Medical Center, Amsterdam, The Netherlands
| | - R W Koster
- Department of Cardiology, Heart Center, Academic Medical Center, Amsterdam, The Netherlands
| | - J Herlitz
- Institute of Internal Medicine, Department of Metabolism and Cardiovascular Research, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - M T Blom
- Department of Cardiology, Heart Center, Academic Medical Center, Amsterdam, The Netherlands
| | - J Kramer-Johansen
- Norwegian National Advisory Unit on Prehospital Emergency Medicine (NAKOS), Air Ambulance Department, Oslo, Norway.,Department of Anaesthesiology Oslo University Hospital and University of Oslo, Oslo, Norway
| | - H L Tan
- Department of Cardiology, Heart Center, Academic Medical Center, Amsterdam, The Netherlands
| | - S G Beesems
- Department of Cardiology, Heart Center, Academic Medical Center, Amsterdam, The Netherlands
| | - M Hulleman
- Department of Cardiology, Heart Center, Academic Medical Center, Amsterdam, The Netherlands
| | - T M Olasveengen
- Department of Anaesthesiology Oslo University Hospital and University of Oslo, Oslo, Norway
| | - F Folke
- Emergency Medical Services Copenhagen, University of Copenhagen, Copenhagen, Denmark.,Department of Cardiology, Copenhagen University Hospital Gentofte, Hellerup, Denmark
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Ayala U, Irusta U, Ruiz J, Eftestøl T, Kramer-Johansen J, Alonso-Atienza F, Alonso E, González-Otero D. A reliable method for rhythm analysis during cardiopulmonary resuscitation. Biomed Res Int 2014; 2014:872470. [PMID: 24895621 PMCID: PMC4033593 DOI: 10.1155/2014/872470] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 03/26/2014] [Accepted: 03/28/2014] [Indexed: 11/29/2022]
Abstract
Interruptions in cardiopulmonary resuscitation (CPR) compromise defibrillation success. However, CPR must be interrupted to analyze the rhythm because although current methods for rhythm analysis during CPR have high sensitivity for shockable rhythms, the specificity for nonshockable rhythms is still too low. This paper introduces a new approach to rhythm analysis during CPR that combines two strategies: a state-of-the-art CPR artifact suppression filter and a shock advice algorithm (SAA) designed to optimally classify the filtered signal. Emphasis is on designing an algorithm with high specificity. The SAA includes a detector for low electrical activity rhythms to increase the specificity, and a shock/no-shock decision algorithm based on a support vector machine classifier using slope and frequency features. For this study, 1185 shockable and 6482 nonshockable 9-s segments corrupted by CPR artifacts were obtained from 247 patients suffering out-of-hospital cardiac arrest. The segments were split into a training and a test set. For the test set, the sensitivity and specificity for rhythm analysis during CPR were 91.0% and 96.6%, respectively. This new approach shows an important increase in specificity without compromising the sensitivity when compared to previous studies.
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Affiliation(s)
- U. Ayala
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain
| | - U. Irusta
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain
| | - J. Ruiz
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain
| | - T. Eftestøl
- Department of Electrical Engineering and Computer Science, Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
| | - J. Kramer-Johansen
- Norwegian Centre for Prehospital Emergency Care (NAKOS), Oslo University Hospital and University of Oslo, 0424 Oslo, Norway
| | - F. Alonso-Atienza
- Department of Signal Theory and Communications, University Rey Juan Carlos, Camino del Molino S/N, 28943 Madrid, Spain
| | - E. Alonso
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain
| | - D. González-Otero
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain
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Ayala U, Eftestøl T, Alonso E, Irusta U, Aramendi E, Wali S, Kramer-Johansen J. Automatic detection of chest compressions for the assessment of CPR-quality parameters. Resuscitation 2014; 85:957-63. [PMID: 24746788 DOI: 10.1016/j.resuscitation.2014.04.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 02/17/2014] [Accepted: 04/09/2014] [Indexed: 10/25/2022]
Abstract
AIM Accurate chest compression detection is key to evaluate cardiopulmonary resuscitation (CPR) quality. Two automatic compression detectors were developed, for the compression depth (CD), and for the thoracic impedance (TI). The objective was to evaluate their accuracy for compression detection and for CPR quality assessment. METHODS Compressions were manually annotated using the force and ECG in 38 out-of-hospital resuscitation episodes, comprising 869 min and 67,402 compressions. Compressions were detected using a negative peak detector for the CD. For the TI, an adaptive peak detector based on the amplitude and duration of TI fluctuations was used. Chest compression rate (CC-rate) and chest compression fraction (CCF) were calculated for the episodes and for every minute within each episode. CC-rate for rescuer feedback was calculated every 8 consecutive compressions. RESULTS The sensitivity and positive predictive value were 98.4% and 99.8% using CD, and 94.2% and 97.4% using TI. The mean CCF and CC-rate obtained from both detectors showed no significant differences with those obtained from the annotations (P>0.6). The Bland-Altman analysis showed acceptable 95% limits of agreement between the annotations and the detectors for the per-minute CCF, per-minute CC-rate, and CC-rate for feedback. For the detector based on TI, only 3.7% of CC-rate feedbacks had an error larger than 5%. CONCLUSION Automatic compression detectors based on the CD and TI signals are very accurate. In most cases, episode review could safely rely on these detectors without resorting to manual review. Automatic feedback on rate can be accurately done using the impedance channel.
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Affiliation(s)
- U Ayala
- Department of Electrical Engineering and Computer Science, Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway; Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain.
| | - T Eftestøl
- Department of Electrical Engineering and Computer Science, Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
| | - E Alonso
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain
| | - U Irusta
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain
| | - E Aramendi
- Communications Engineering Department, University of the Basque Country UPV/EHU, Alameda Urquijo S/N, 48013 Bilbao, Spain
| | - S Wali
- Department of Electrical Engineering and Computer Science, Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
| | - J Kramer-Johansen
- Norwegian Centre for Prehospital Emergency Care (NAKOS), OsloUniversity Hospital and University of Oslo, Pb 4956 Nydalen, 0424 Oslo, Norway
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Ruiz J, Alonso E, Aramendi E, Kramer-Johansen J, Eftestøl T, Ayala U, González-Otero D. Reliable extraction of the circulation component in the thoracic impedance measured by defibrillation pads. Resuscitation 2013; 84:1345-52. [DOI: 10.1016/j.resuscitation.2013.05.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 05/03/2013] [Accepted: 05/23/2013] [Indexed: 10/26/2022]
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Ruiz J, Ayala U, de Gauna SR, Irusta U, González-Otero D, Alonso E, Kramer-Johansen J, Eftestøl T. Feasibility of automated rhythm assessment in chest compression pauses during cardiopulmonary resuscitation. Resuscitation 2013; 84:1223-8. [DOI: 10.1016/j.resuscitation.2013.01.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 01/17/2013] [Accepted: 01/29/2013] [Indexed: 10/27/2022]
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Aramendi E, Ayala U, Irusta U, Alonso E, Eftestøl T, Kramer-Johansen J. Suppression of the cardiopulmonary resuscitation artefacts using the instantaneous chest compression rate extracted from the thoracic impedance. Resuscitation 2012; 83:692-8. [DOI: 10.1016/j.resuscitation.2011.11.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 10/14/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
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Birkenes T, Myklebust H, Neset A, Olasveengen T, Kramer-Johansen J. Video analysis of dispatcher-rescuer teamwork—Effects on CPR technique and quality. Resuscitation 2010. [DOI: 10.1016/j.resuscitation.2010.09.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mykletun R, Neset A, Birkenes T, Furunes T, Myklebust H, Odegaard S, Olasveengen T, Kramer-Johansen J. Cognitive and emotional coping strategies used during CPR in full scale cardiac arrest simulation—A qualitative analysis of post-test interviews. Resuscitation 2010. [DOI: 10.1016/j.resuscitation.2010.09.401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Neset A, Birkenes T, Furunes T, Myklebust H, Mykletun R, Odegaard S, Olasveengen T, Kramer-Johansen J. Stress and CPR quality in a full scale clinical cardiac arrest simulation compared to a traditional test—A randomised trial. Resuscitation 2010. [DOI: 10.1016/j.resuscitation.2010.09.212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Brunner S, Eilevstjønn J, Ødegaard S, Kramer-Johansen J, Myklebust H. Why is compression depth less consistent on humans than on manikins? Resuscitation 2010. [DOI: 10.1016/j.resuscitation.2010.09.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Gundersen K, Kvaløy J, Kramer-Johansen J, Steen P, Eftestøl T. Using ECG-analysis to quantify the effect of increasing pre-shock pauses in chest compressions on the probability of ROSC. Resuscitation 2008. [DOI: 10.1016/j.resuscitation.2008.03.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Ødegaard S, Olasveengen T, Wik L, Kramer-Johansen J. Quality of CPR during transport of patients after out-of-hospital cardiac arrest. Resuscitation 2008. [DOI: 10.1016/j.resuscitation.2008.03.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Gundersen K, Kvaløy J, Kramer-Johansen J, Olasveengen J, Eilevstjønn T, Eftestøl T. The effect of using within-patient correlation to improve shock outcome prediction. Resuscitation 2008. [DOI: 10.1016/j.resuscitation.2008.03.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Kvaløy J, Skogvoll E, Eftestøl T, Gundersen K, Kramer-Johansen J, Olasveengen T, Steen P. Identifying factors influencing clinical state transitions in cardiac arrest resuscitation. Resuscitation 2008. [DOI: 10.1016/j.resuscitation.2008.03.215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Kramer-Johansen J, Dorph E, Steen PA. Detection of carbon dioxide in expired air after oesophageal intubation; the role of bystander mouth-to-mouth ventilation. Acta Anaesthesiol Scand 2008; 52:155-7. [PMID: 17999713 DOI: 10.1111/j.1399-6576.2007.01503.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The identification of a correctly placed tube during anaesthesia routinely depends on the detection of carbon dioxide (CO2) in the expired air. RESULTS We describe a previously unreported cause of false-positive prediction in two patients with high initial values of CO2 in expired air after oesophageal intubation. Both patients had received bystander cardiopulmonary resuscitation with mouth-to-mouth ventilation, and the CO2 from the rescuers' expired air was trapped and subsequently detected after oesophageal intubation.
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Affiliation(s)
- J Kramer-Johansen
- Institute for Experimental Medical Research and Pre-Hospital Division, Ullevål University Hospital, Oslo, Norway.
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Tomlinson AE, Nysaether J, Kramer-Johansen J, Steen PA, Dorph E. Compression force–depth relationship during out-of-hospital cardiopulmonary resuscitation. Resuscitation 2007; 72:364-70. [PMID: 17141936 DOI: 10.1016/j.resuscitation.2006.07.017] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 07/08/2006] [Accepted: 07/13/2006] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recent clinical studies reporting the high frequency of inadequate chest compression depth (<38 mm) during CPR, have prompted the question if adult human chest characteristics render it difficult to attain the recommended compression depth in certain patients. MATERIAL AND METHODS Using a specially designed monitor/defibrillator equipped with a sternal pad fitted with an accelerometer and a pressure sensor, compression force and depth was measured during CPR in 91 adult out-of-hospital cardiac arrest patients. RESULTS There was a strong non-linear relationship between the force of compression and depth achieved. Mean applied force for all patients was 30.3+/-8.2 kg and mean absolute compression depth 42+/-8 mm. For 87 of 91 patients 38 mm compression depth was obtained with less than 50 kg. Stiffer chests were compressed more forcefully than softer chests (p<0.001), but softer chests were compressed more deeply than stiffer chests (p=0.001). The force needed to reach 38 mm compression depth (F38) and mean compression force were higher for males than for females: 29.8+/-14.5 kg versus 22.5+/-10.2 kg (p<0.02), and 32.0+/-8.3 kg versus 27.0+/-7.0 kg (p<0.01), respectively. There was no significant variation in F38 or compression depth with age, but a significant 1.5 kg mean decrease in applied force for each 10 years increase in age (p<0.05). Chest stiffness decreased significantly (p<0.0001) with an increasing number of compressions performed. Average residual force during decompression was 1.7+/-1.0 kg, corresponding to an average residual depth of 3+/-2 mm. CONCLUSION In most out-of-hospital cardiac arrest victims adequate chest compression depth can be achieved by a force<50 kg, indicating that an average sized and fit rescuer should be able to perform effective CPR in most adult patients.
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Affiliation(s)
- A E Tomlinson
- Institute for Experimental Medical Research, Ulleval University Hospital, N-0407 Oslo, Norway
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Melsom MN, Kramer-Johansen J, Flatebø T, Müller C, Nicolaysen G. Distribution of pulmonary ventilation and perfusion measured simultaneously in awake goats. Acta Physiol Scand 1997; 159:199-208. [PMID: 9079150 DOI: 10.1046/j.1365-201x.1997.92355000.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Gravity has been regarded as the major determinant for local pulmonary perfusion and ventilation. Recent reports, describing major gravity independent heterogeneity in both variables, have questioned the importance of gravity. We asked to what extent ventilation and perfusion were related, and if they showed similar distributions along the vertical axis in the lung. We gave 99mTc-aerosols as tracers for ventilation and radioactive microspheres as blood flow tracers in five awake goats over 4 min. Ventilation and perfusion were determined in approximately 1.5 cm3 pieces of the lung. For both variables the vertical distribution could vary considerably from lung to lung, but within each lung the two distributions were similar. Both ventilation and perfusion were heterogeneously distributed (CV approximately 40% for both), they were highly correlated (r = 0.81) and the average 25-75-interpercentile interval for ventilation to perfusion ratio (0.84-1.13) was significantly less wide than for both ventilation (0.76-1.38) and perfusion (0.76-1.40). Some pieces were considerably overventilated while a few were correspondingly underventilated. This could indicate that perfusion is adjusted to ventilation in normoxic lungs with a low sensitivity to overventilation.
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Affiliation(s)
- M N Melsom
- Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Norway
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Melsom MN, Flatebø T, Kramer-Johansen J, Aulie A, Sjaastad OV, Iversen PO, Nicolaysen G. Both gravity and non-gravity dependent factors determine regional blood flow within the goat lung. Acta Physiol Scand 1995; 153:343-53. [PMID: 7618481 DOI: 10.1111/j.1748-1716.1995.tb09872.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Distribution of pulmonary blood flow has traditionally been regarded as determined by gravity. This view has been challenged recently by reports describing marked gravity-independent distribution of flow. These reports were based on experiments in which local blood flow was measured by methods that have not been thoroughly evaluated. In the present study, we showed that in the goat lung regional trapping of i.v. infused microspheres (O = 15 microns) correlated to endothelial uptake of a simultaneously i.v. infused diamine (r = 0.99, region size approximately 1.5 cm3, dry weight approximately 40 mg). This indicates that the deposition of microspheres reflects true regional pulmonary blood flow. Using the microsphere method, we found a marked gravity-independent heterogeneity in blood flow (coefficient of variation approximately 40%) in the awake goat. We could find no pattern related to anatomy that could account for this variability. We re-examined the influence of gravity by analysing the distribution of pulmonary blood flow in anaesthetized goats both in prone and supine positions. The dorsal to sternal distribution of flow appeared to be inverted when the animals were turned from prone to supine recumbency, indicating that gravity influenced the distribution of pulmonary blood flow along this axis. However, along the gravitational axis, distribution of blood flow varied considerably from lung to lung. It appears that in awake goats the distribution of pulmonary blood flow is the result of several different determinants.
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Affiliation(s)
- M N Melsom
- Department of Physiology, University of Oslo, Norway
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