Diagnosis of aortic dissection by transesophageal echocardiography during cardiopulmonary resuscitation

Focused Ultrasonography in Cardiac Arrest

Rapid diagnostic tools available to the emergency physician caring for cardiac arrest patients are limited. Focused ultrasound (US), and in particular, focused echocardiography, is a useful tool in the evaluation of patients in cardiac arrest. It can help identify possible causes of cardiac arrest like tamponade and pulmonary embolism, which can guide therapy. US can also yield prognostic information, with lack of cardiac activity being highly specific for failure to achieve return of spontaneous circulation. US may also be used to aid in procedural guidance. Recently, focused transesophageal echocardiography has been used in the emergency department setting.

Indications, Clinical Impact, and Complications of Critical Care Transesophageal Echocardiography: A Scoping Review

BACKGROUND

Critical care transesophageal echocardiography (ccTEE) is an increasingly popular tool used by intensivists to characterize and manage hemodynamics at the bedside. Its usage appears to be driven by expanded diagnostic scope as well as the limitations of transthoracic echocardiography (TTE) - lack of acoustic windows, patient positioning, and competing clinical interests (eg, the need to perform chest compressions). The objectives of this scoping review were to determine the indications, clinical impact, and complications of ccTEE.

METHODS

MEDLINE, EMBASE, Cochrane, and six major conferences were searched without a time or language restriction on March 31^st, 2021. Studies were included if they assessed TEE performed for adult critically ill patients by intensivists, emergency physicians, or anesthesiologists. Intraoperative or post-cardiac surgical TEE studies were excluded. Study demographics, indication for TEE, main results, and complications were extracted in duplicate.

RESULTS

Of the 4403 abstracts screened, 289 studies underwent full-text review, with 108 studies (6739 patients) included. Most studies were retrospective (66%), performed in academic centers (84%), in the intensive care unit (73%), and were observational (55%). The most common indications for ccTEE were hemodynamic instability, trauma, cardiac arrest, respiratory failure, and procedural guidance. Across multiple indications, ccTEE was reported to change the diagnosis in 52% to 78% of patients and change management in 32% to79% patients. During cardiac arrest, ccTEE identified the cause of arrest in 25% to 35% of cases. Complications of ccTEE included two cases of significant gastrointestinal bleeding requiring intervention, but no other major complications (death or esophageal perforation) reported.

CONCLUSIONS

The use of ccTEE has been described for the diagnosis and management of a broad range of clinical problems. Overall, ccTEE was commonly reported to offer additional diagnostic yield beyond TTE with a low observed complication rate. Additional high quality ccTEE studies will permit stronger conclusions and a more precise understanding of the trends observed in this scoping review.

Incidence of acute aortic dissections in patients with out of hospital cardiac arrest: A systematic review and meta-analysis of observational studies

Objectives

Acute Aortic dissection (AAD) may present as out-of-hospital cardiac arrest (OHCA). However, the incidence of this presentation is not well known. Our aim was to perform a systematic review and meta-analysis of all observational studies reporting on the incidence of AAD in patients with OHCA.

Methods

We searched MEDLINE, CENTRAL, PsycInfo, Web of Science Core Collection and OpenGrey databases from inception to March-2021, for observational studies reporting on the incidence of AAD in patients with OHCA. Data was pooled using a random-effects model of proportions. The primary outcome was the incidence of AAD in OHCA patients. Secondary outcomes were the incidence of type A aortic dissections (TAAD) and type B aortic dissections (TBAD) in OHCA patients, overall mortality following AAD-OHCA and risk of death in AAD-OHCA patients compared to risk of death of non-AAD-OHCA patients.

Results

Fourteen studies were included. The pooled calculated incidence of OHCA due to AAD was 4.39% (95 %CI: 2.55; 6.8). Incidence of OHCA due to TAAD was 7.18% (95 %CI: 5.61; 8.93) and incidence of OHCA due to TBAD was 0.47% (95 %CI: 0.18; 0.85). Overall mortality following OHCA due to AAD was 100% (95 %CI: 97.62; 100). The risk of death in AAD-OHCA patients compared with non-AAD-OHCA patients was 1.10 (95 %CI: 0.94; 1.30).

Conclusion

AAD as a cause of OHCA is more frequent than previously thought. Prognosis is dire, as it is invariably lethal. These findings should lead to a higher awareness of AAD when approaching a patient with OHCA and to future studies on this matter.

Transoesophageal echocardiography in cardiac arrest: A systematic review

AIMS

To identify, appraise and synthesize all available clinical evidence to evaluate the diagnostic role of transoesophageal echocardiography (TEE) during resuscitation of in-hospital (IHCA) and out-of-hospital cardiac arrest (OHCA) in the identification of reversible causes of cardiac arrest and cardiac contractility.

METHODS

We conducted a systematic review following PRISMA guidelines. Medline, EMBASE, Web of Science Core Collection, Proquest Dissertations, Open Grey, CDSR, Cochrane Central, Cochrane Clinical Answers, and the clinicaltrials.gov registry were searched for eligible studies. Studies involving adult patients, with non-traumatic cardiac arrest in whom TEE was used for intra-arrest evaluation, were included. Case studies and case series, animal studies, reviews, guidelines and editorials were excluded. The QUADAS-2 tool was used for quality assessment of all studies.

RESULTS

Eleven studies with a total of 358 patients were included. Four studies involved perioperative IHCA, three involved OHCA, and four were mixed population settings. Overall, the risk of bias in the selected studies was either high or unclear due to evidence or lack of information. In all 11 studies, TEE allowed the identification of reversible causes of arrest. We found significant heterogeneity in the criteria used to interpret findings, TEE protocol used, and timing of TEE.

CONCLUSION

Due to heterogeneity of studies, small sample size and inconsistent reference standard, the evidence for TEE in cardiac arrest resuscitation is of low certainty and is affected by a high risk of bias. Further studies are needed to better understand the true diagnostic accuracy of TEE in identifying reversible causes of arrest and cardiac contractility.