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Three Part Question

In [adults in cardiac arrest] does [Emergency Physician performed bedside transthoracic echocardiography] have [accurate prognostic accuracy]?

Clinical Scenario

A 62 year old male emergency patient arrives in cardiac arrest. During resuscitation he is found to have pulseless electrical activity (PEA). Several rounds of ACLS are performed with no improvement in the patient's condition. You wonder if a rapid bedside cardiac ultrasound (echocardiography) would be of any prognostic or diagnostic utility.

Search Strategy

Ovid Medline(R) 1950 to August 2011



((exp ultrasonography OR exp echocardiography) AND (exp cardiopulmonary resuscitation OR exp heart arrest OR cardiac arrest)). Limited to English and human.

Search Outcome

457 papers were found of which six were considered relevant to the three-part question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Niendorff et al, 2005, USA	17 consecutive patients suffering 18 PEA arrests over a 6 month period at a major academic hospital. Bedside echocardiography was attempted in 7 arrests and completed in 5	Prospective feasibility study	Evaluate performance and reliability of Ultrasound assessment as an integrated part of the ACLS PEA arrest protocol	In four of five cases the nonexpert interpretation was confirmed	Extremely small sample size. Low compliance with study protocol. No follow up on cause of PEA arrest. Non-Emergency Physicians with limited ultrasound training.
Blaivas and Fox , 2001, USA	Convenience sample of 169 adult non-traumatic patients arriving to a single ED over a 20-month period receiving ongoing CPR. Rapid bedside echocardiogram was performed during pulse check pauses. No patients with cardiac standstill on arrival (136) survived to leave the ED. 100% of patients presenting with asystole (65) had cardiac standstill on initial ECHO.	Prospective observational study	Survival of patients with cardiac motion at arrival to the ED.	20 patients (12/67% with PEA, 8/53% with VF) survived to leave the ED. 13 patients (6/33% in PEA, 7/47% in VF) died despite cardiac activity on arrival.	Small convenience sample (800 eligible pts during study). No follow-up of survivors. 'Survival' included only to hospital admission.
			Survival of patients in asystole on arrival to the ED.	No patients (65) in asystole on arrival survived. 100% had cardiac standstill on ultrasound.
			Survival of patients arriving to the ED with cardiac standstill.	No patients (136) arriving with cardiac standstill on ultrasound survived to leave the ED.
Salen et al, 2005, USA	Convenience sample of 70 adult non-traumatic patients arriving to four EDs over a 12-month period in either PEA or asystole. Rapid bedside echocardiogram was performed during pulse check pauses by Emergency Physicians.	Prospective observational study	Survival of patients arriving with cardiac standstill	No patients with cardiac standstill on arrival (59/70) survived to leave the hospital	Convenience sample. Small sample size. Resuscitation teams were not blinded to US results. Most patients arrived with cardiac standstill. 17 of 70 subjects did not get sequential US exams.
			Return of spontaneous circulation	0 of 59 patients with cardiac standstill had ROSC. 8/11 patients in PEA with cardiac motion had ROSC.
			Survival to hospital discharge	Only 1/8 patients survived to hospital discharge
Salen et al, 2001, USA	102 nonconsecutive adult pulseless non-traumatic patients presenting to 2 community EDs over a 12 month period. All received a subxiphoid cardiac ultrasound during CPR pauses. 53 also had capnography levels recorded.	Prospective clinical observational study	Survival to hospital admission	27% (11/41) of patients with cardiac motion survived to admission vs. 3% (2/61) of patients with cardiac standstill.	Convenience sample. No quantification of cardiac contractility. Only measured survival to admission. Small sample size. Resuscitation team not blinded to ultrasound results.
			Usefulness of US in management of cardiac arrest	96% of EPs felt US was helpful.
			Presence of pericardial effusion	4% (4/102) of patients had a pericardial effusion
Tayal and Kline, 2003, USA	Twenty adult patients arriving at the ED in non-traumatic hemodynamic collapse over an 18 month period at a level 1 trauma center.	Prospective observational study	Cardiac standstill	8/20 (40%) were in cardiac standstill	Not randomized. Small sample size. Selection bias (higher pre-test probability of pericardial effusion). Resuscitation team not blinded to ultrasound results Patients not necessarily in cardiac arrest, inclusion criteria included patients with hypotension
			Survival	None of the 8 in cardiac standstill survived
			Pericardial Effusion	8/12 (69%) of patients with cardiac activity had pericardial effusions. Bedside Echo diagnosed tamponade in 3 cases.
Hayhurst et al, 2011, UK	Convenience sample of 56 patients in cardiac arrest recruited over a 29-month period from two hospitals. Six patients excluded because scans were performed outside the cardiac arrest period	Prospective feasibility study	Return of spontaneous circulation	Ventricular wall movement present in 20 cases, 11 had ROSC. 1 Patients without VWM had ROSC	Small study
			Survival to ED discharge	Four patients with VWM and one patient without VWM survived to ED discharge

Comment(s)

Cardiac standstill on bedside echocardiography performed during cardiac arrest is an extremely poor prognostic indicator. Only 0.9% of patients with cardiac standstill across all six studies (3/320) survived to hospital admission. One study, Niendorff DF et al, demonstrated that non-emergency physicians with minimal ultrasound experience might carry out inadequate examinations and/or misinterpret the results. However, in the other four studies where this was examined, for all studying emergency physicians in EDs with formal ultrasound training programmes, there was excellent correlation between EP and radiologist interpretations and quick and reliable assessments of cardiac activity were obtained. Several cases of tamponade were identified at the bedside and emergent drainage permitted survival to hospital admission. Few physicians felt that the sonography interfered with, or delayed, resuscitation. All the studies had small sample sizes and the resuscitation teams were not blinded to the ultrasound results. However, the results were highly consistent between studies and cardiac standstill was almost universally associated with failed resuscitations.

Editor Comment

ACLS, advanced cardiac life support; CPR, cardiopulmonary resuscitation; ED, emergency department; EP, emergency physician; PEA, pulseless electrical activity; ROSC, return of spontaneous circulation; US, ultrasound; VWM, ventricular wall movement.

Clinical Bottom Line

Cardiac standstill seen on physician-performed bedside echocardiography during cardiac arrest virtually predicts unsuccessful resuscitation. Even physicians with minimal training can reliably differentiate cardiac standstill from contractile myocardium. Experienced EP sonographers can also use bedside echocardiography to accurately diagnose reversible causes of cardiac arrest (ie, pericardial effusion, hypovolaemia, right heart strain, etc) and therefore potentially improve their patient's prognosis by treating the underlying process.

References

1. Niendorff DF, Rassias AJ, Palac R, et al. Rapid cardiac ultrasound of inpatients suffering PEA arrest performed by nonexpert sonographers Resuscitation 2005; 67: 81-87.
2. Blaivas M, Fox JCl. Outcome in cardiac arrest patients found to have cardiac standstill on the bedside emergency department echocardogram Acad Emerg Med 2001;8:616-62.
3. 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; 23:459-462
4. 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: 610-15.
5. Tayal VS, Kline JA. Emergency echocardiography to detect pericardial effusion in patients in PEA and near-PEA states Resuscitation 2003;59: 315-318.
6. 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;28:119–21.