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Three Part Question

In [patients with in-hospital cardiac arrest],does [ventricular activity seen on POCUS], [predict the ability to obtain ROSC]?

Clinical Scenario

EMS brings in a 65-year-old female who was found weak and confused at home after being found on the ground by her spouse. You complete a general assessment and rule out any major injuries. Unfortunately, you find that the patient cannot give you a useful history due to her confusion and decide to call her spouse for more information. As you are calling her spouse, the patient's nurse alerts you that she suddenly lost her pulse. Chest compressions are on-going as you enter the room and find she has PEA at the next pulse and rhythm check. You perform POCUS and find there is evidence of cardiac activity. You wonder what the likelihood of obtaining ROSC will be.

Search Strategy

OVID Medline was searched since inception until January 19, 2023.
Inclusion criteria for studies included research involving in-hospital cardiac arrest and use of point of care ultrasound.

Exclusion criteria included studies investigating:
- Pediatric or animal subjects
- Formal echocardiography
- Ultrasonography done after the resuscitation
- traumatic cardiac arrest
- case reports or narrative reviews
- Out of hospital cardiac arrests. In studies that were mixed, at least 50% needed to be IHCA to be included.

[[point of care.mp. or exp Point-of-Care Systems] OR [exp Ultrasonography/ or POCUS.mp.] OR ultraso$.mp. OR exp Echocardiography/ OR echo$.mp. OR bedside.mp.]] AND [[cardiac arrest.mp. or exp Heart Arrest/] OR IHCA.mp OR in hospital cardiac arrest.mp. OR xp Cardiopulmonary Resuscitation/]] AND [ROSC.mp. OR exp Survival/ or survival.mp.]

Search Outcome

710 studies were screened by title and abstract after duplicates were excluded. 27 studies were selected to proceed to full text review. 8 articles met inclusion criteria including 4 systematic reviews and 4 primary research studies. Only the primary research articles were considered for final analysis.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Chardoli, Mojtaba; Heidari, Farhad; Rabiee, Helaleh; Sharif-Al 2012 Iran	100 patients in PEA in 2 academic emergency departments	Patients were randomized to two groups, A, which utilized POCUS during their pauses in standard ACLS, and B, which maintained standard ACLS care without ultrasonography. Ultrasonographers were not the physicians leading the code, and could feed back any findings related to the ethology of PEA back to the leader except mechanical ventricular activity. The ultrasonographer utilized a subxiphoid cardiac view.	ROSC	34% in POCUS + ACLS vs 28% in ACLS; p=0.52	This was a randomized trial but there was no mention of blinding involved. There was no indication as to how the groups were randomized or how many different sonographers were used. There was no table 1 demonstrating the demographics between the groups, however, the few demographics that were mentioned in the text appeared to be well balanced (age, gender). There was no mention if any of these patients were out-of-hospital arrests or if they all occurred in the emegengency department.
			Presence of mechanical ventricular activity during resuscitation	Presence was found in 43% of patients with ROSC; absence was found in 100% of participants who died.
			Etiology of arrest	Ultrasonographic findings of hypovolemia and mild-moderate pericardial effusion were found in 22% and 14% respectively. There were no findings of reversible etiology in the standard care group.
Devia Jaramillo, German; Navarrete Aldana, Norberto; Rojas Ortiz, Zaira 2020 Colombia	108 adult patients with cardiac arrest excluding VT/VF arrest in the emergency department	This was a historic cohort study collecting data in patients meeting inclusion criteria from June 2018- June 2019. Excluded patients included traumatic arrests, patients transferred to outside centres, and those in VT/VF arrest. 88% of the study patients experienced in hospital cardiac arrest. Images obtained included parasternal long axis, apical 4-5 chamber, and subxiphoid cardiac views	Cardiac and valvular activity and ROSC	Patients with cardiac and valvular activity on ultrasound had significantly higher rates of ROSC (85.7 vs 42.1; p=0.011) compared to those with just valvular activity	No clear outcomes were stated. It appears that this study used retrospectively collected data to try and determine which variables are associated with better cardiac arrest outcomes without having a specific focused question. There were some methodological inconsistencies and they included patients that they said they would exclude. VT/VF patients were excluded from their analysis, but the results had 15% of patients with VT/VF. They stated that ultrasound was performed on every patient, however the results reported that only 85% had ultrasound done.
Flato et al. 2015 Brazil	49 adult patients admitted to ICU with subsequent development of PEA or asystolic cardiac arrest.	This was a prospective observational cohort study that involved ICU patients in cardiac arrest (PEA or asystole). Patients were not included in the study if there was no physician trained in ultrasonography available. Cardiac ultrasonography was conducted during ACLS care by trained physician sonographers according to the FEEL protocol.	ROSC > 20 min	Pseudo-PEA as identified by US was associated with a significantly higher rate of ROSC (19/27) than true PEA (1/5) and asystole (4/17). OR 8.08 (CI 95% 2.21- 29.48).	The study population was heterogenous and had numerous significant comorbidities, however, this likely reflects the true population of ICU patients. There were 88 total cases identified for eligibility in the study with 39 exclusions. Of the 39 patients excluded, 25 were not included due lack of available sonographer. This is greater than half of their published study population and could have bolstered their small sample size.
			Diagnosis	In 51% of cases POCUS provided a cause for PEA. POCUS was able to identify PEA vs pseudo-PEA (5 vs 27).
Salen et al. 2001 USA	Participants were 102 adult cardiac arrest patients in two community emergency departments.	This was a prospective observational study. Participants underwent focused cardiac sonography primarily via the subxiphoid view by emergency physicians and residents during the pulse check in a standard ACLS cardiac arrest protocol. There were no written inclusion or exclusion criteria. Apical 4-chamber view was used in patients who were obese or had difficult to obtain subxiphoid views.	Survival rates to hospital admission	Patients with sonographically detected cardiac activity at any time were significantly more likely to survive to hospital admission (27% vs 3%; p <0.001). 100% of patients with sonographically detected cardiac activity during each ultrasound check (6/6) survived to admission, vs 7% of those who lacked contractions at any time (p<0.001).	There is a lack of baseline patient characteristics, therefore we don't know if those without cardiac function on ultrasound also had other reasons for worse outcomes. There was no specification whether patients had an in-hopsital or out of hospital arrest (i.e. were brought in pulseless and had CPR in the field for 30 min vs arrested in the ER). This limits the specific application of results.

Comment(s)

A 2x2 table was constructed using the the data from the 4 studies above and test characteristics were calculated. There were 4 systematic reviews identified in the literature. No additional relevant studies were found by searching through the references of the systematic reviews. All primary research studies lacked blinding and there was no indication that compliance to the intervention or non-intervention (i.e. standard ACLS without POCUS) was maintained. There was only one study that compared POCUS + ACLS to ACLS standard of care. Unfortunately we are lacking high quality randomized controlled trials in this domain that would better inform future research and clinical care.

Clinical Bottom Line

Ultrasound detected cardiac activity during in-hospital cardiac arrest has a sensitivity of 77.9% (77.6-78.2 95%CI) and a specificity of 64.7% (64.5-64.9 95%CI) for obtaining ROSC.

References

1. Chardoli, Mojtaba; Heidari, Farhad; Rabiee, Helaleh; Sharif-Alhoseini, Mahdi; Shokoohi, Hamid; Rahimi-Movaghar, Vafa Echocardiography integrated ACLS protocol versus conventional cardiopulmonary resuscitation in patients with pulseless electrical activity cardiac arrest. Chinese Journal of Traumatology 2012; 284-287
2. Devia Jaramillo, German; Navarrete Aldana, Norberto; Rojas Ortiz, Zaira Rhythms and prognosis of patients with cardiac arrest, emphasis on pseudo- pulseless electrical activity: another reason to use ultrasound in emergency rooms in Colombia International Journal of Emergency Medicine 2020
3. Flato, Uri Adrian Prync; Paiva, Edison Ferreira; Carballo, Mariana Teixeira; Buehler, Anna Maria; Marco, Roberto; Timerman, Ari Echocardiography for prognostication during the resuscitation of intensive care unit patients with non-shockable rhythm cardiac arrest Resuscitation 2015; 1-6
4. Salen, P; O'Connor, R; Sierzenski, P; Passarello, B; Pancu, D; Melanson, S; Arcona, S; Reed, J; Heller, M Can cardiac sonography and capnography be used independently and in combination to predict resuscitation outcomes? Academic Emergency Medicine 2001; 610-615