ASAIO Journal 2014
Clinical Critical Care
Perioperative Use of the Imacor Hemodynamic Transesophageal Echocardiography Probe in Cardiac Surgery Patients: Initial Experience Konrad Sarosiek, Christopher Y. Kang, Caitlyn M. Johnson, Harrison Pitcher, Hitoshi Hirose, and Nicholas C. Cavarocchi
Echocardiography is the standard to assess heart function although obtaining transesophageal echocardiography (TEE) on an emergent basis may be limited by its availability. A transoral miniaturized hemodynamic TEE (hTEE) probe (ImaCor Inc.) was developed to provide direct visualization of the heart, and we hypothesized that the probe could provide hemodynamic information useful for patient management. Data from 2011 to 2012 was retrospectively collected. Four hundred ninety patients were treated in the cardiovascular intensive care unit of which 61 underwent hTEE monitoring and were divided into three groups: patients on extracorporeal membrane oxygenation (ECMO) (n = 25), ventricular assist device (VAD) (n = 6), and others (n = 30). Patient charts were reviewed to investigate the indications for the use of hTEE, findings, and the interventions performed. The indications for probe insertion were hemodynamic instability (n = 32), ECMO weaning (n = 10), VAD alarm (n = 1), tamponade (n = 14), pulmonary embolism (n = 2), and intra-aortic balloon pump wean (n = 2). In all 61 cases, we were successfully able to diagnose and treat the etiology of instability based on the hTEE findings. Utilization of the hTEE probe successfully diagnosed and aided therapy in all patients with hemodynamic instability refractory to initial therapy and provides a valuable tool to aid clinicians in the management of postoperative hemodynamics. ASAIO Journal 2014; 60:553–558.
volume following fluid administration.1 The failure of pressure measurements to correlate with ventricular volume is secondary to changes in myocardial compliance resulting from cardiac surgery.1 The relationship between pressure, volume, and flow is further altered in the setting of mechanical circulatory support—including ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO). Although most decisions for straightforward patients can be made with readily available information, complex patients with acute situations may need more comprehensive investigations. Another modality of cardiac monitoring is the visualization of the cardiac silhouette through echocardiography.2 In the cardiac operating room, anesthesiologists make hemodynamic assessments and subsequent interventions using transesophageal echocardiography (TEE).3 Imaging obtained from TEE allows for an accurate assessment of cardiac function and volume status. However, while TEE is readily available in the operating room, obtaining one in the intensive care unit (ICU) requires additional time and personnel. In the ICU, TEE serves as the gold standard for determining the cause of hemodynamic instability,4 although the assembly of additional equipment and staff can delay the intervention. Meanwhile, if clinicians have a high suspicion that the TEE will reveal a possible indication for surgical intervention (eg, cardiac tamponade), the operating room is commonly placed on standby for emergent surgery while the clinician awaits the study. To overcome the widespread lack of availability of conventional TEE, a miniaturized TEE probe (ImaCor Inc., Garden City, NY) with a diameter of 5.5 mm was developed. The hemodynamic TEE (hTEE) probe is inserted transorally and can transmit images of the cardiac silhouette from its resting place in the esophagus. The images allow for an immediate assessment of cardiac function and volume status, while, at the same time, intensivists may make additional decisions to improve a patient’s hemodynamics because the probe can remain indwelling for up to 72 hours. In this report, we describe our experience using the hTEE probe and review its ability to be used as a point-of-care device to guide management or make the appropriate diagnosis
Key Words: hemodynamic monitoring, cardiac surgery, TEE
Following high-risk cardiac surgery, optimization of fluid and hemodynamic status is fundamental during perioperative patient care. Historically, central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) as determined from pulmonary artery catheters (PACs) were surrogates for ventricular volume to guide fluid resuscitation; however, in recent years, studies have shown that CVP and PCWP do not always have a predictable correlation to ventricular preload and do not adequately reflect the change in intravascular
From the Department of Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania. Submitted for consideration July 2013; accepted for publication in revised form June 2014. Disclosure: The authors have no conflicts of interest to report. Reprint Requests: Nicholas C. Cavarocchi, MD, Department of Surgery, Thomas Jefferson University Hospital, 1025 Walnut St., Ste. 605, Philadelphia, PA 19107. Email: [email protected]. Copyright © 2014 by the American Society for Artificial Internal Organs
Methods Patients From May 2011 through June 2012, a total of 490 patients were admitted to our ICU. The ImaCor hTEE system was used as a point-of-care device in 61 (12%) patients. Patients who had the hTEE probe used experienced a triggering event during which conventional methods of assessing hemodynamics
DOI: 10.1097/MAT.0000000000000113
553
554 SAROSIEK et al. Table 1. Patient Demographics, All Data Are Shown as n (%) Except Age
Age, mean ± SD Male Primary diagnosis ECMO Ventricular assist device Other Coronary artery bypass Transplant Valve surgery Thoracic surgery Aortic surgery Myocardial infarction General surgery
Patients With hTEE (n = 61)
Patients Without hTEE (n = 429)
56 ± 13 40 (66%)
63 ± 13 296 (69%)
25 (41%) 6 (10%)
30 (7%) 26 (6%)
< 0.0001 0.2670
8 (13%) 5 (8%) 3 (5%) 2 (3%) 6 (10%) 4 (7%) 2 (3%)
240 (56%)* 13 (3%) 173 (40%)* N/A 27 (6%)* N/A N/A
Clinical Critical Care
Perioperative Use of the Imacor Hemodynamic Transesophageal Echocardiography Probe in Cardiac Surgery Patients: Initial Experience Konrad Sarosiek, Christopher Y. Kang, Caitlyn M. Johnson, Harrison Pitcher, Hitoshi Hirose, and Nicholas C. Cavarocchi
Echocardiography is the standard to assess heart function although obtaining transesophageal echocardiography (TEE) on an emergent basis may be limited by its availability. A transoral miniaturized hemodynamic TEE (hTEE) probe (ImaCor Inc.) was developed to provide direct visualization of the heart, and we hypothesized that the probe could provide hemodynamic information useful for patient management. Data from 2011 to 2012 was retrospectively collected. Four hundred ninety patients were treated in the cardiovascular intensive care unit of which 61 underwent hTEE monitoring and were divided into three groups: patients on extracorporeal membrane oxygenation (ECMO) (n = 25), ventricular assist device (VAD) (n = 6), and others (n = 30). Patient charts were reviewed to investigate the indications for the use of hTEE, findings, and the interventions performed. The indications for probe insertion were hemodynamic instability (n = 32), ECMO weaning (n = 10), VAD alarm (n = 1), tamponade (n = 14), pulmonary embolism (n = 2), and intra-aortic balloon pump wean (n = 2). In all 61 cases, we were successfully able to diagnose and treat the etiology of instability based on the hTEE findings. Utilization of the hTEE probe successfully diagnosed and aided therapy in all patients with hemodynamic instability refractory to initial therapy and provides a valuable tool to aid clinicians in the management of postoperative hemodynamics. ASAIO Journal 2014; 60:553–558.
volume following fluid administration.1 The failure of pressure measurements to correlate with ventricular volume is secondary to changes in myocardial compliance resulting from cardiac surgery.1 The relationship between pressure, volume, and flow is further altered in the setting of mechanical circulatory support—including ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO). Although most decisions for straightforward patients can be made with readily available information, complex patients with acute situations may need more comprehensive investigations. Another modality of cardiac monitoring is the visualization of the cardiac silhouette through echocardiography.2 In the cardiac operating room, anesthesiologists make hemodynamic assessments and subsequent interventions using transesophageal echocardiography (TEE).3 Imaging obtained from TEE allows for an accurate assessment of cardiac function and volume status. However, while TEE is readily available in the operating room, obtaining one in the intensive care unit (ICU) requires additional time and personnel. In the ICU, TEE serves as the gold standard for determining the cause of hemodynamic instability,4 although the assembly of additional equipment and staff can delay the intervention. Meanwhile, if clinicians have a high suspicion that the TEE will reveal a possible indication for surgical intervention (eg, cardiac tamponade), the operating room is commonly placed on standby for emergent surgery while the clinician awaits the study. To overcome the widespread lack of availability of conventional TEE, a miniaturized TEE probe (ImaCor Inc., Garden City, NY) with a diameter of 5.5 mm was developed. The hemodynamic TEE (hTEE) probe is inserted transorally and can transmit images of the cardiac silhouette from its resting place in the esophagus. The images allow for an immediate assessment of cardiac function and volume status, while, at the same time, intensivists may make additional decisions to improve a patient’s hemodynamics because the probe can remain indwelling for up to 72 hours. In this report, we describe our experience using the hTEE probe and review its ability to be used as a point-of-care device to guide management or make the appropriate diagnosis
Key Words: hemodynamic monitoring, cardiac surgery, TEE
Following high-risk cardiac surgery, optimization of fluid and hemodynamic status is fundamental during perioperative patient care. Historically, central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) as determined from pulmonary artery catheters (PACs) were surrogates for ventricular volume to guide fluid resuscitation; however, in recent years, studies have shown that CVP and PCWP do not always have a predictable correlation to ventricular preload and do not adequately reflect the change in intravascular
From the Department of Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania. Submitted for consideration July 2013; accepted for publication in revised form June 2014. Disclosure: The authors have no conflicts of interest to report. Reprint Requests: Nicholas C. Cavarocchi, MD, Department of Surgery, Thomas Jefferson University Hospital, 1025 Walnut St., Ste. 605, Philadelphia, PA 19107. Email: [email protected]. Copyright © 2014 by the American Society for Artificial Internal Organs
Methods Patients From May 2011 through June 2012, a total of 490 patients were admitted to our ICU. The ImaCor hTEE system was used as a point-of-care device in 61 (12%) patients. Patients who had the hTEE probe used experienced a triggering event during which conventional methods of assessing hemodynamics
DOI: 10.1097/MAT.0000000000000113
553
554 SAROSIEK et al. Table 1. Patient Demographics, All Data Are Shown as n (%) Except Age
Age, mean ± SD Male Primary diagnosis ECMO Ventricular assist device Other Coronary artery bypass Transplant Valve surgery Thoracic surgery Aortic surgery Myocardial infarction General surgery
Patients With hTEE (n = 61)
Patients Without hTEE (n = 429)
56 ± 13 40 (66%)
63 ± 13 296 (69%)
25 (41%) 6 (10%)
30 (7%) 26 (6%)
< 0.0001 0.2670
8 (13%) 5 (8%) 3 (5%) 2 (3%) 6 (10%) 4 (7%) 2 (3%)
240 (56%)* 13 (3%) 173 (40%)* N/A 27 (6%)* N/A N/A
