Feasibility of diagnosis of postcardiotomy tamponade by miniaturized transesophageal echocardiography

Is hemodynamic transesophageal echocardiography needed for patients with left ventricular assist device?

BACKGROUND

Interventions in patients with a left ventricular assist device (LVAD) in the intensive care unit (ICU) are typically performed based on the results of conventional monitoring, such as vital signs and Swan-Ganz catheter (SGC) and LVAD parameters. These variables might not always accurately reflect a patient's cardiac function, volume status, and interventricular septal configuration, however. To assess the accuracy of standard monitoring, we performed routine continuous hemodynamic transesophageal echocardiography (hTEE) to evaluate cardiac function, volume status, and septal position.

METHODS

Between 2011 and 2015, 93 HeartMate II LVADs were implanted. The study group comprised 30 patients with an SGC in place who were monitored routinely by hTEE in the ICU every 1 to 3 hours until extubation. A total of 147 hTEE studies were analyzed retrospectively to observe differences between conventional monitoring and hTEE.

RESULTS

Among the 30 patients studied, 26 (87%) had at least 1 disagreement between conventional monitoring and hTEE findings. In 22 patients (73%), at least 1 of the hTEE studies was abnormal whereas conventional parameters were normal. Abnormal hTEE findings included a shift in the interventricular septum in 19 patients (63%), abnormal ventricular volume status in 22 patients (73%), and right ventricular failure in 9 patients (30%). Based on conventional monitoring, none of the patients required an LVAD speed change, whereas hTEE showed that 14 patients (47%) needed an LVAD speed adjustment.

CONCLUSIONS

Conventional monitoring in the ICU might not provide an accurate representation of cardiac function, ventricular volume status, or septal position in patients with LVAD. Continuous monitoring with hTEE in patients with an LVAD may help guide optimal intervention in the ICU setting during the early postoperative period.

Transthoracic and transoesophageal echocardiography: a systematic review of feasibility and impact on diagnosis, management and outcome after cardiac surgery

Transthoracic and transoesophageal echocardiography are increasingly used as tools to improve clinical assessment following cardiac surgery. However, most physicians are not trained in echocardiography, and there is no widespread agreement on the feasibility, indications or effect on outcome of transthoracic or transoesophageal echocardiography for patients after cardiac surgery. We performed a systematic review of electronic databases for focused transthoracic and transoesophageal echocardiography after cardiac surgery which revealed 15 full-text articles. They consistently reported that echocardiography is feasible, whether performed by a novice or expert, and frequently resulted in important changes in diagnosis of cardiac abnormalities and their management. However, most were observational studies and there were no well-designed trials investigating the impact of echocardiography on outcome. We conclude that both transthoracic and transoesophageal echocardiography are useful following cardiac surgery.

Feasibility and influence of hTEE monitoring on postoperative management in cardiac surgery patients

Monoplane hemodynamic TEE (hTEE) monitoring (ImaCor(®) ClariTEE(®)) might be a useful alternative to continuously evaluate cardiovascular function and we aimed to investigate the feasibility and influence of hTEE monitoring on postoperative management in cardiac surgery patients. After IRB approval we reviewed the electronic data of cardiac surgery patients admitted to our intensive care between 01/01/2012 and 30/06/2013 in a case-controlled matched-pairs design. Patients were eligible for the study when they presented a sustained hemodynamic instability postoperatively with the clinical need of an extended hemodynamic monitoring: (a) hTEE (hTEE group, n = 18), or (b) transpulmonary thermodilution (control group, n = 18). hTEE was performed by ICU residents after receiving an approximately 6-h hTEE training session. For hTEE guided hemodynamic optimization an institutional algorithm was used. The hTEE probe was blindly inserted at the first attempt in all patients and image quality was at least judged to be adequate. The frequency of hemodynamic examinations was higher (ten complete hTEE examinations every 2.6 h) in contrast to the control group (one examination every 8 h). hTEE findings, including five unexpected right heart failure and one pericardial tamponade, led to a change of current therapy in 89% of patients. The cumulative dose of epinephrine was significantly reduced (p = 0.034) and levosimendan administration was significantly increased (p = 0.047) in the hTEE group. hTEE was non-inferior to the control group in guiding norepinephrine treatment (p = 0.038). hTEE monitoring performed by ICU residents was feasible and beneficially influenced the postoperative management of cardiac surgery patients.