Does Point-of-care Ultrasound Improve Survival when Used During Cardiac Arrest? A Systematic Review and Meta-analysis
Main Article Content
Abstract
Aim of the review: This review aimed to evaluate the impact of Point-of-care Ultrasound during cardio- pulmonary resuscitation for adult non-traumatic CA on clinical outcomes and survival.
Data sources: This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed and Embase databases were searched on 14 November 2022. The eligibility criteria were studies including: adults with non-traumatic cardiac arrest and Point-of-care Ultrasound utilisation, a control group, and an analysis of short- and long-term outcomes and neurological outcomes. The risk of bias and certainty of evidence were assessed using the Grading of Recommendations Assessment, Development and Evaluation form. Data are reported as risk of ratios for each outcome.
Results: From the two databases, 7658 studies were identified, of which 3 met the predefined eligibility criteria. The main findings showed no difference in rate of return of spontaneous circulation (RR 0.83, 95% CI 0.24–1.66, p=0.60) (very low certainty of evidence) and a significant decrease in rate of survival to hospital discharge (RR 0.44, 95% CI 0.22–0.88, p=0.02) (very low quality of evidence). No study reported data regarding neurological status at hospital discharge, 30-day survival rate, or neurological outcome.
Conclusion: The impact of Point-of-care Ultrasound during cardiopulmonary resuscitation on clinical outcomes during cardiac arrest is hampered by the very low certainty of evidence, heterogeneity, and high risk of bias. Studies have shown no difference in return of spontaneous circulation but a significant decrease in survival to hospital discharge when Point-of-care Ultrasound was performed.
Keywords:
POCUS, cardiac arrest, resuscitation, systematic review, meta-analysis
Article Details
How to Cite
VENTORP, Simon; WAGNER, Henrik; HÄRDIG, Bjarne Madsen.
Does Point-of-care Ultrasound Improve Survival when Used During Cardiac Arrest? A Systematic Review and Meta-analysis.
Medical Research Archives, [S.l.], v. 11, n. 8, aug. 2023.
ISSN 2375-1924.
Available at: <https://esmed.org/MRA/mra/article/view/4235>. Date accessed: 04 dec. 2024.
doi: https://doi.org/10.18103/mra.v11i8.4235.
Section
Review Articles
The Medical Research Archives grants authors the right to publish and reproduce the unrevised contribution in whole or in part at any time and in any form for any scholarly non-commercial purpose with the condition that all publications of the contribution include a full citation to the journal as published by the Medical Research Archives.
References
1. Smallwood N, Dachsel M. Point-of-care ultrasound (POCUS): unnecessary gadgetry or evidence-based medicine? Clin Med (Lond) 2018;18(3):219–24.
2. Labovitz AJ, Noble VE, Bierig M, et al. Focused cardiac ultrasound in the emergent setting: a consensus statement of the American Society of Echocardiography and American College of Emergency Physicians. J Am Soc Echocardiogr 2010;23(12):1225–30.
3. Desbiens NA. Simplifying the diagnosis and management of pulseless electrical activity in adults: a qualitative review. Crit Care Med 2008;36(2):391–6.
4. Hayhurst C, Lebus C, Atkinson PR, et al. An evaluation of echo in life support (ELS): is it feasible? What does it add? Emerg Med J 2011;28(2):119–21.
5. Ozen C, Salcin E, Akoglu H, Onur O, Denizbasi A. Assessment of ventricular wall motion with focused echocardiography during cardiac arrest to predict survival. Turk J Emerg Med 2016;16(1):12–6.
6. Salen P, O'Connor R, Sierzenski P, et al. Can cardiac sonography and capnography be used independently and in combination to predict resuscitation outcomes? Acad Emerg Med 2001;8(6):610–5.
7. Salen P, Melniker L, Chooljian C, et al. Does the presence or absence of sonographically identified cardiac activity predict resuscitation outcomes of cardiac arrest patients? Am J Emerg Med 2005; 23(4):459–62.
8. Tomruk O, Erdur B, Cetin G, Ergin A, Avcil M, Kapci M. Assessment of cardiac ultrasonography in predicting outcome in adult cardiac arrest. J Int Med Res 2012;40(2):804–9.
9. Aichinger G, Zechner PM, Prause G, et al. Cardiac movement identified on prehospital echocardiography predicts outcome in cardiac arrest patients. Prehosp Emerg Care 2012;16(2):251–5.
10. Breitkreutz R, Uddin S, Steiger H, et al. Focused echocardiography entry level: new concept of a 1-day training course. Minerva Anestesiol 2009;75(5):285–92.
11. Breitkreutz R, Walcher F, Seeger FH. Focused echocardiographic evaluation in resuscitation management: concept of an advanced life support-conformed algorithm. Crit Care Med 2007;35(5 Suppl):S150–61.
12. Hernandez C, Shuler K, Hannan H, Sonyika C, Likourezos A, Marshall J. C.A.U.S.E.: Cardiac arrest ultra-sound exam--a better approach to managing patients in primary non-arrhythmogenic cardiac arrest. Resuscitation 2008;76(2):198–206.
13. Gardner KF, Clattenburg EJ, Wroe P, Singh A, Mantuani D, Nagdev A. The Cardiac Arrest Sonographic Assessment (CASA) exam - A standardized approach to the use of ultrasound in PEA. Am J Emerg Med 2018;36(4):729–31.
14. Reed MJ, Gibson L, Dewar A, Short S, Black P, Clegg GR. Introduction of paramedic led Echo in Life Support into the pre-hospital environment: The PUCA study. Resuscitation 2017;112:65–9.
15. Testa A, Cibinel GA, Portale G, et al. The proposal of an integrated ultrasonographic approach into the ALS algorithm for cardiac arrest: the PEA protocol. Eur Rev Med Pharmacol Sci 2010;14(2):77–88.
16. Lichtenstein D, Malbrain ML. Critical care ultrasound in cardiac arrest. Technological requirements for performing the SESAME-protocol--a holistic approach. Anaesthesiol Intensive Ther 2015;47(5):471–81.
17. Atkinson P, Bowra J, Milne J, et al. International Federation for Emergency Medicine Consensus Statement: Sonography in hypotension and cardiac arrest (SHoC): An international consensus on the use of point of care ultrasound for undifferentiated hypotension and during cardiac arrest. CJEM 2017;19(6):459–70.
18. Bughrara N, Herrick SL, Leimer E, Sirigaddi K, Roberts K, Pustavoitau A. Focused Cardiac Ultrasound and the Periresuscitative Period: A Case Series of Resident-Performed Echocardiographic Assessment Using Subcostal-Only View in Advanced Life Support. A A Pract 2020;14(10):e01278.
19. Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll. Emerg Med Clin North Am 2010;28(1):29–56.
20. Hussein L, Rehman MA, Jelic T, et al. Transoesophageal echocardiography in cardiac arrest: A systematic review. Resuscitation 2021;168:167–75.
21. Botker MT, Jacobsen L, Rudolph SS, Knudsen L. The role of point of care ultrasound in prehospital critical care: a systematic review. Scand J Trauma Resusc Emerg Med 2018;26(1):51.
22. Dudek M, Szarpak L, Peacock FW, et al. Diagnostic performance of point-of-use ultrasound of resuscitation outcomes: A systematic review and meta-analysis of 3265 patients. Cardiol J 2021. https://doi.org/10.5603/CJ.a2021.0044.
23. Long B, Alerhand S, Maliel K, Koyfman A. Echocardiography in cardiac arrest: An emergency medicine review. Am J Emerg Med 2018;36(3):488–93.
24. Reynolds JC, Issa MS, Nicholson TC, et al. Prognostication with point-of-care echocardiography during cardiac arrest: A systematic review. Resuscitation 2020;152:56–68.
25. Brooke M, Walton J, Scutt D. Paramedic application of ultrasound in the management of patients in the prehospital setting: a review of the literature. Emerg Med J 2010;27(9):702–7.
26. Rudolph SS, Sorensen MK, Svane C, Hesselfeldt R, Steinmetz J. Effect of prehospital ultrasound on clinical outcomes of non-trauma patients--a systematic review. Resuscitation 2014;85(1):21–30.
27. Soar J, Callaway CW, Aibiki M, et al. Part 4: Advanced life support: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation 2015;95:e71–120.
28. Prosen G, Križmarić M, Završnik J, Grmec S. Impact of modified treatment in echocardiographically confirmed pseudo-pulseless electrical activity in out-of-hospital cardiac arrest patients with constant end-tidal carbon dioxide pressure during compression pauses. J Int Med Res 2010;38(4):1458–67.
29. Higgins JPT, Thomas J, Chandler J, et al. Cochrane Handbook for Systematic Reviews of Interventions version 6.3 (updated February 2022). Cochrane, 2022. Available from: www.training.cochrane.org/handbook.
30. Guyatt G, Oxman AD, Akl EA, et al. GRADE guidelines: 1. Introduction-GRADE evidence profiles and summary of findings tables. J Clin Epidemiol 2011;64(4):383–94.
31. Perkins GD, Jacobs IG, Nadkarni VM, et al. Cardiac arrest and cardiopulmonary resuscitation outcome reports: update of the Utstein Resuscitation Registry Templates for Out-of-Hospital Cardiac Arrest: a statement for healthcare professionals from a task force of the International Liaison Committee on Resuscitation (American Heart Association, European Resuscitation Council, Australian and New Zealand Council on Resuscitation, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Southern Africa, Resuscitation Council of Asia); and the American Heart Association Emergency Cardiovascular Care Committee and the Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation. Circulation 2015;132(13):1286–300.
32. Balshem H, Helfand M, Schünemann HJ, et al. GRADE guidelines: 3. Rating the quality of evidence. J Clin Epidemiol 2011;64(4):401–6.
33. Morley PT, Atkins DL, Finn JC, et al. Evidence Evaluation Process and Management of Potential Conflicts of Interest: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Resuscitation 2020;156:a23–a34.
34. Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ 2003;327(7414):557–60.
35. Atkinson PR, Beckett N, French J, Banerjee A, Fraser J, Lewis D. Does Point-of-care Ultrasound Use Impact Resuscitation Length, Rates of Intervention, and Clinical Outcomes During Cardiac Arrest? A Study from the Sonography in Hypotension and Cardiac Arrest in the Emergency Department (SHoC-ED) Investigators. Cureus 2019;11(4):e4456.
36. Chardoli M, Heidari F, Rabiee H, Sharif-Alhoseini M, Shokoohi H, Rahimi-Movaghar V. Echocardiography integrated ACLS protocol versus conventional cardiopulmonary resuscitation in patients with pulseless electrical activity cardiac arrest. Chin J Traumatol 2012;15(5):284–7.
37. Chou EH, Wang CH, Monfort R, et al. Association of ultrasound-related interruption during cardiopulmonary resuscitation with adult cardiac arrest outcomes: A video-reviewed retrospective study. Resuscitation 2020;149:74–80.
38. Pyo SY, Park GJ, Kim SC, Kim H, Lee SW, Lee JH. Impact of the modified SESAME ultrasound protocol implementation on patients with cardiac arrest in the emergency department. Am J Emerg Med 2021;43:62–8.
39. Guyatt GH, Oxman AD, Kunz R, et al. GRADE guidelines 6. Rating the quality of evidence--imprecision. J Clin Epidemiol 2011; 64(12):1283–93.
40. Wood L, Egger M, Gluud LL, et al. Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study. BMJ 2008;336(7644):601–5.
41. Ioannidis JP, Haidich AB, Pappa M, et al. Comparison of evidence of treatment effects in randomized and nonrandomized studies. JAMA 2001;286(7):821–30.
42. Lalande E, Burwash-Brennan T, Burns K, et al. Is point-of-care ultrasound a reliable predictor of outcome during atraumatic, non-shockable cardiac arrest? A systematic review and meta-analysis from the SHoC investigators. Resuscitation 2019;139:159–66.
43. Soar J, Berg KM, Andersen LW, et al. Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation 2020;156:a80–a119.
44. Blanco P, Martinez Buendia C. Point-of-care ultrasound in cardiopulmonary resuscitation: a concise review. J Ultrasound 2017;20(3):193–8.
45. Reynolds JC, Nicholson T, O'Neil B, Drennan IR, Issa M, Welsford M. Diagnostic test accuracy of point-of-care ultrasound during cardiopulmonary resuscitation to indicate the etiology of cardiac arrest: A systematic review. Resuscitation 2022;172:54–63.
46. Gaspari R, Weekes A, Adhikari S, et al. Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest. Resuscitation 2016;109:33–9.
47. Reynolds JC, Frisch A, Rittenberger JC, Callaway CW. Duration of resuscitation efforts and functional outcome after out-of-hospital cardiac arrest: when should we change to novel therapies? Circulation 2013;128(23):2488–94.
48. Kim WY, Ahn S, Hong JS, et al. The impact of downtime on neurologic intact survival in patients with targeted temperature management after out-of-hospital cardiac arrest: National multicenter cohort study. Resuscitation 2016;105:203–8.
49. Kim HB, Suh JY, Choi JH, Cho YS. Can serial focussed echocardiographic evaluation in life support (FEEL) predict resuscitation outcome or termination of resuscitation (TOR)? A pilot study. Resuscitation 2016;101:21–6.
50. Lien WC, Hsu SH, Chong KM, et al. US-CAB protocol for ultrasonographic evaluation during cardiopulmonary resuscitation: Validation and potential impact. Resuscitation 2018; 127:125–31.
51. Ketelaars R, Beekers C, Van Geffen GJ, Scheffer GJ, Hoogerwerf N. Prehospital Echocardiography During Resuscitation Impacts Treatment in a Physician-Staffed Helicopter Emergency Medical Service: an Observational Study. Prehosp Emerg Care 2018;22(4):406–13.
2. Labovitz AJ, Noble VE, Bierig M, et al. Focused cardiac ultrasound in the emergent setting: a consensus statement of the American Society of Echocardiography and American College of Emergency Physicians. J Am Soc Echocardiogr 2010;23(12):1225–30.
3. Desbiens NA. Simplifying the diagnosis and management of pulseless electrical activity in adults: a qualitative review. Crit Care Med 2008;36(2):391–6.
4. Hayhurst C, Lebus C, Atkinson PR, et al. An evaluation of echo in life support (ELS): is it feasible? What does it add? Emerg Med J 2011;28(2):119–21.
5. Ozen C, Salcin E, Akoglu H, Onur O, Denizbasi A. Assessment of ventricular wall motion with focused echocardiography during cardiac arrest to predict survival. Turk J Emerg Med 2016;16(1):12–6.
6. Salen P, O'Connor R, Sierzenski P, et al. Can cardiac sonography and capnography be used independently and in combination to predict resuscitation outcomes? Acad Emerg Med 2001;8(6):610–5.
7. Salen P, Melniker L, Chooljian C, et al. Does the presence or absence of sonographically identified cardiac activity predict resuscitation outcomes of cardiac arrest patients? Am J Emerg Med 2005; 23(4):459–62.
8. Tomruk O, Erdur B, Cetin G, Ergin A, Avcil M, Kapci M. Assessment of cardiac ultrasonography in predicting outcome in adult cardiac arrest. J Int Med Res 2012;40(2):804–9.
9. Aichinger G, Zechner PM, Prause G, et al. Cardiac movement identified on prehospital echocardiography predicts outcome in cardiac arrest patients. Prehosp Emerg Care 2012;16(2):251–5.
10. Breitkreutz R, Uddin S, Steiger H, et al. Focused echocardiography entry level: new concept of a 1-day training course. Minerva Anestesiol 2009;75(5):285–92.
11. Breitkreutz R, Walcher F, Seeger FH. Focused echocardiographic evaluation in resuscitation management: concept of an advanced life support-conformed algorithm. Crit Care Med 2007;35(5 Suppl):S150–61.
12. Hernandez C, Shuler K, Hannan H, Sonyika C, Likourezos A, Marshall J. C.A.U.S.E.: Cardiac arrest ultra-sound exam--a better approach to managing patients in primary non-arrhythmogenic cardiac arrest. Resuscitation 2008;76(2):198–206.
13. Gardner KF, Clattenburg EJ, Wroe P, Singh A, Mantuani D, Nagdev A. The Cardiac Arrest Sonographic Assessment (CASA) exam - A standardized approach to the use of ultrasound in PEA. Am J Emerg Med 2018;36(4):729–31.
14. Reed MJ, Gibson L, Dewar A, Short S, Black P, Clegg GR. Introduction of paramedic led Echo in Life Support into the pre-hospital environment: The PUCA study. Resuscitation 2017;112:65–9.
15. Testa A, Cibinel GA, Portale G, et al. The proposal of an integrated ultrasonographic approach into the ALS algorithm for cardiac arrest: the PEA protocol. Eur Rev Med Pharmacol Sci 2010;14(2):77–88.
16. Lichtenstein D, Malbrain ML. Critical care ultrasound in cardiac arrest. Technological requirements for performing the SESAME-protocol--a holistic approach. Anaesthesiol Intensive Ther 2015;47(5):471–81.
17. Atkinson P, Bowra J, Milne J, et al. International Federation for Emergency Medicine Consensus Statement: Sonography in hypotension and cardiac arrest (SHoC): An international consensus on the use of point of care ultrasound for undifferentiated hypotension and during cardiac arrest. CJEM 2017;19(6):459–70.
18. Bughrara N, Herrick SL, Leimer E, Sirigaddi K, Roberts K, Pustavoitau A. Focused Cardiac Ultrasound and the Periresuscitative Period: A Case Series of Resident-Performed Echocardiographic Assessment Using Subcostal-Only View in Advanced Life Support. A A Pract 2020;14(10):e01278.
19. Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll. Emerg Med Clin North Am 2010;28(1):29–56.
20. Hussein L, Rehman MA, Jelic T, et al. Transoesophageal echocardiography in cardiac arrest: A systematic review. Resuscitation 2021;168:167–75.
21. Botker MT, Jacobsen L, Rudolph SS, Knudsen L. The role of point of care ultrasound in prehospital critical care: a systematic review. Scand J Trauma Resusc Emerg Med 2018;26(1):51.
22. Dudek M, Szarpak L, Peacock FW, et al. Diagnostic performance of point-of-use ultrasound of resuscitation outcomes: A systematic review and meta-analysis of 3265 patients. Cardiol J 2021. https://doi.org/10.5603/CJ.a2021.0044.
23. Long B, Alerhand S, Maliel K, Koyfman A. Echocardiography in cardiac arrest: An emergency medicine review. Am J Emerg Med 2018;36(3):488–93.
24. Reynolds JC, Issa MS, Nicholson TC, et al. Prognostication with point-of-care echocardiography during cardiac arrest: A systematic review. Resuscitation 2020;152:56–68.
25. Brooke M, Walton J, Scutt D. Paramedic application of ultrasound in the management of patients in the prehospital setting: a review of the literature. Emerg Med J 2010;27(9):702–7.
26. Rudolph SS, Sorensen MK, Svane C, Hesselfeldt R, Steinmetz J. Effect of prehospital ultrasound on clinical outcomes of non-trauma patients--a systematic review. Resuscitation 2014;85(1):21–30.
27. Soar J, Callaway CW, Aibiki M, et al. Part 4: Advanced life support: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation 2015;95:e71–120.
28. Prosen G, Križmarić M, Završnik J, Grmec S. Impact of modified treatment in echocardiographically confirmed pseudo-pulseless electrical activity in out-of-hospital cardiac arrest patients with constant end-tidal carbon dioxide pressure during compression pauses. J Int Med Res 2010;38(4):1458–67.
29. Higgins JPT, Thomas J, Chandler J, et al. Cochrane Handbook for Systematic Reviews of Interventions version 6.3 (updated February 2022). Cochrane, 2022. Available from: www.training.cochrane.org/handbook.
30. Guyatt G, Oxman AD, Akl EA, et al. GRADE guidelines: 1. Introduction-GRADE evidence profiles and summary of findings tables. J Clin Epidemiol 2011;64(4):383–94.
31. Perkins GD, Jacobs IG, Nadkarni VM, et al. Cardiac arrest and cardiopulmonary resuscitation outcome reports: update of the Utstein Resuscitation Registry Templates for Out-of-Hospital Cardiac Arrest: a statement for healthcare professionals from a task force of the International Liaison Committee on Resuscitation (American Heart Association, European Resuscitation Council, Australian and New Zealand Council on Resuscitation, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Southern Africa, Resuscitation Council of Asia); and the American Heart Association Emergency Cardiovascular Care Committee and the Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation. Circulation 2015;132(13):1286–300.
32. Balshem H, Helfand M, Schünemann HJ, et al. GRADE guidelines: 3. Rating the quality of evidence. J Clin Epidemiol 2011;64(4):401–6.
33. Morley PT, Atkins DL, Finn JC, et al. Evidence Evaluation Process and Management of Potential Conflicts of Interest: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Resuscitation 2020;156:a23–a34.
34. Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ 2003;327(7414):557–60.
35. Atkinson PR, Beckett N, French J, Banerjee A, Fraser J, Lewis D. Does Point-of-care Ultrasound Use Impact Resuscitation Length, Rates of Intervention, and Clinical Outcomes During Cardiac Arrest? A Study from the Sonography in Hypotension and Cardiac Arrest in the Emergency Department (SHoC-ED) Investigators. Cureus 2019;11(4):e4456.
36. Chardoli M, Heidari F, Rabiee H, Sharif-Alhoseini M, Shokoohi H, Rahimi-Movaghar V. Echocardiography integrated ACLS protocol versus conventional cardiopulmonary resuscitation in patients with pulseless electrical activity cardiac arrest. Chin J Traumatol 2012;15(5):284–7.
37. Chou EH, Wang CH, Monfort R, et al. Association of ultrasound-related interruption during cardiopulmonary resuscitation with adult cardiac arrest outcomes: A video-reviewed retrospective study. Resuscitation 2020;149:74–80.
38. Pyo SY, Park GJ, Kim SC, Kim H, Lee SW, Lee JH. Impact of the modified SESAME ultrasound protocol implementation on patients with cardiac arrest in the emergency department. Am J Emerg Med 2021;43:62–8.
39. Guyatt GH, Oxman AD, Kunz R, et al. GRADE guidelines 6. Rating the quality of evidence--imprecision. J Clin Epidemiol 2011; 64(12):1283–93.
40. Wood L, Egger M, Gluud LL, et al. Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study. BMJ 2008;336(7644):601–5.
41. Ioannidis JP, Haidich AB, Pappa M, et al. Comparison of evidence of treatment effects in randomized and nonrandomized studies. JAMA 2001;286(7):821–30.
42. Lalande E, Burwash-Brennan T, Burns K, et al. Is point-of-care ultrasound a reliable predictor of outcome during atraumatic, non-shockable cardiac arrest? A systematic review and meta-analysis from the SHoC investigators. Resuscitation 2019;139:159–66.
43. Soar J, Berg KM, Andersen LW, et al. Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation 2020;156:a80–a119.
44. Blanco P, Martinez Buendia C. Point-of-care ultrasound in cardiopulmonary resuscitation: a concise review. J Ultrasound 2017;20(3):193–8.
45. Reynolds JC, Nicholson T, O'Neil B, Drennan IR, Issa M, Welsford M. Diagnostic test accuracy of point-of-care ultrasound during cardiopulmonary resuscitation to indicate the etiology of cardiac arrest: A systematic review. Resuscitation 2022;172:54–63.
46. Gaspari R, Weekes A, Adhikari S, et al. Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest. Resuscitation 2016;109:33–9.
47. Reynolds JC, Frisch A, Rittenberger JC, Callaway CW. Duration of resuscitation efforts and functional outcome after out-of-hospital cardiac arrest: when should we change to novel therapies? Circulation 2013;128(23):2488–94.
48. Kim WY, Ahn S, Hong JS, et al. The impact of downtime on neurologic intact survival in patients with targeted temperature management after out-of-hospital cardiac arrest: National multicenter cohort study. Resuscitation 2016;105:203–8.
49. Kim HB, Suh JY, Choi JH, Cho YS. Can serial focussed echocardiographic evaluation in life support (FEEL) predict resuscitation outcome or termination of resuscitation (TOR)? A pilot study. Resuscitation 2016;101:21–6.
50. Lien WC, Hsu SH, Chong KM, et al. US-CAB protocol for ultrasonographic evaluation during cardiopulmonary resuscitation: Validation and potential impact. Resuscitation 2018; 127:125–31.
51. Ketelaars R, Beekers C, Van Geffen GJ, Scheffer GJ, Hoogerwerf N. Prehospital Echocardiography During Resuscitation Impacts Treatment in a Physician-Staffed Helicopter Emergency Medical Service: an Observational Study. Prehosp Emerg Care 2018;22(4):406–13.