ORIGINAL PAPER

Feasibility and influence of hTEE monitoring on postoperativemanagement in cardiac surgery patients

S. Treskatsch1 • F. Balzer1 • F. Knebel2 • M. Habicher1 •

J. P. Braun3 • M. Kastrup1 • H. Grubitzsch4 •

K.-D. Wernecke5 • C. Spies1 • M. Sander1

Received: 26 March 2015 / Accepted: 1 June 2015 / Published online: 6 June 2015

� Springer Science+Business Media Dordrecht 2015

Abstract Monoplane hemodynamic TEE (hTEE) moni-

toring (ImaCor�ClariTEE�) might be a useful alternative to

continuously evaluate cardiovascular function andwe aimed

to investigate the feasibility and influence of hTEE moni-

toring 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 examina-

tion 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 cumula-

tive dose of epinephrine was significantly reduced

(p = 0.034) and levosimendan administration was signifi-

cantly 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 post-

operative management of cardiac surgery patients.

Keywords Goal directed therapy � Echocardiography �hTEE � Monoplane probe � Cardiac surgery � Postoperativemanagement

Abbreviations

GDT Goal-directed therapy

DO2 Delivery of oxygen

CO Cardiac output

LCOS Low cardiac output syndrome

hTEE Hemodynamic monoplane transesophageal

echocardiography

ICU Intensive care unit

PICCO� Pulse contour cardiac output (monitor)

ESC European Society of Cardiology

EACVI European Association of Cardiovascular

Imaging

EACTA European Association of Cardiothoracic

Anaesthesiologists

TG SAX Transgastric short axis (view)

Electronic supplementary material The online version of thisarticle (doi:10.1007/s10554-015-0689-8) contains supplementarymaterial, which is available to authorized users.

& S. Treskatsch

sascha.treskatsch@charite.de

1 Department of Anesthesiology and Intensive Care Medicine,

Campus Charite Mitte and Campus Virchow Klinikum,

Charite - Universitatsmedizin Berlin, Chariteplatz 1,

10117 Berlin, Germany

2 Department of Cardiology, Campus Charite Mitte, Charite -

Universitatsmedizin Berlin, Berlin, Germany

3 Department of Anesthesiology, Intensive Care Medicine and

Pain Therapy, Klinikum Hildesheim GmbH, Hildesheim,

Germany

4 Department of Cardiovascular Surgery, Campus Charite

Mitte, Charite - Universitatsmedizin Berlin, Berlin, Germany

5 SOSTANA GmbH, Berlin, Germany

123

Int J Cardiovasc Imaging (2015) 31:1327–1335

DOI 10.1007/s10554-015-0689-8

4C Midesophageal four chamber (view)

SVC Superior vena cava (view)

LV Left ventricle

RV Right ventricle

IAS Interatriale septum

TEE Multiplane transesophageal echocardiography

SD Standard deviation

IQR Interquartiles

SAPS-II Simplified acute physiology score II

NYHA New York Heart Association

CPB Cardiopulmonary bypass

CABG Coronary bypass grafting

VR Valve reconstruction and/or replacement

EVLWI Extravascular lung water index

Introduction

Several studies in the last decade found benefit in ‘‘goal

directed therapy’’ (GDT) [1, 2]. Goal directed fluid

administration reduced the length of hospital stay [3] and

improved patient outcome after surgery [4, 5]. Excessive

fluid restriction consistently increased the level of hypov-

olemia and the incidence of postoperative complications

[6]. The fundamental principle behind GDT is optimization

of oxygen delivery to tissues (DO2) by optimizing car-

diovascular function using fluids, catecholamines, red

blood cells and supplementary oxygen [7].

Cardiac output (CO) is one of the major determinates of

oxygen delivery [8]. CO depends on: (a) preload,

(b) afterload, (c) myocardial contractility, (d) valve func-

tion and (e) heart rate/rhythm, all of which can be exam-

ined using echocardiography. Postoperative low cardiac

output syndrome (LCOS), especially in cardiac surgery,

thus results in deficient oxygen delivery. Therefore, in

cases of unexplained life-threatening hemodynamic insta-

bility—possibly persisting despite corrective therapy—a

multiplane transesophageal echocardiographic examination

is recommended (Class I indication) to identify the

underlying pathophysiological cause, e.g. hypovolemia,

reduced myocardial contractility, pericardial tamponade

[9], and to guide goal-directed therapy [10, 11].

However, in practice conventional transesophgeal

echocardiography can only be performed intermittently

[12]. Hence, the new ImaCor� ClariTEE� might be a

useful alternative in daily clinical practice. Because of its

small size it can be introduced orally in the patients

esophagus and can remain up to 72 h in situ. With its

flexible probe tip the three most important two-dimensional

views of the heart can be obtained on demand to identify

and manage the pathophysiological causes of LCOS, thus

the name ‘‘hemodynamic TEE’’ (hTEE).

Up to now, there have only been a few clinical trials

investigating the possible benefit of using the ImaCor�

ClariTEE� to guide hemodynamic therapy in high-risk

surgical and/or critically ill patients [13–19]. Monoplane

TEE in the hands of intensivists has been shown to provide

clinically useful estimates of LV function, RV dilation,

hypovolemia and occurrence of pericardial effusion, as

shown evaluated by between experienced echocardiogra-

phers [16]. Furthermore, hTEE frequently led to changes in

clinical management of hemodynamic unstable patients on

ventilator support [15] and also of patients on ventricular

assist devices [14]. We were therefore interested in the

feasibility (=ease of insertion and technical operation) and

influence (=utility as hemodynamic monitor) of hTEE

monitoring on postoperative management in cardiac sur-

gery patients during its clinical implementation.

Methods

After approval of the Charite Ethics Committee, Berlin,

Germany (Study ID number: EA1-249-13; ClinGov. reg-

istration number: NCT02046954), we reviewed charts and

data derived from two electronic patient data management

systems (PDMS: COPRA GmbH, Sasbachwalden, Ger-

many and SAP AG, Walldorf, Germany) of cardiac surgery

patients admitted to our intensive care unit (ICU) of the

department of anesthesiology and intensive care medicine

at the Campus Charite Mitte, Berlin, between 01/01/2012

and 30/06/2013. Written informed consent was waived by

the ethics committee.

Patients were eligible for the study when they presented

with a sustained hemodynamic instability (i.e. lasting

longer than 1 h after ICU admission) despite corrective

therapy, and needed extended hemodynamic monitoring

according to current recommendations [20, 21]. Hemody-

namic instability was clinically defined as (two or more

criteria): persistent tachycardia (heart rate [100/min),

arterial hypotension (mean arterial pressure\60 mmHg),

need for catechlominergic support (norepinephrine

C0.1 lg/kg/min in combination with epinephrine C0.1 lg/kg/min and/or dobutamine C5 lg/kg/min and/or enoxi-

mone C1 lg/kg/min), lactate acidosis (pH\ 7.2) and/or

negative base excess (BE\-2 mmol/l), declining diure-

sis (\0.5 ml/kg/h), and/or suspicion of pericardial tam-

ponade. Those criteria were used to define ‘‘hemodynamic

instability’’ for the purpose of increasing assay sensitivity

by (a) detecting the most hemodynamic compromised

patients by means of (b) the most frequently documented

values in the local PDMS. In order to estimate the influence

of hTEE monitoring, we retrospectively investigated the

following time periods where (a) hTEE (01/10/2012–30/

06/2013), or (b) transpulmonary thermodilution (PICCO�,

1328 Int J Cardiovasc Imaging (2015) 31:1327–1335

123

bolus administration technique) (01/01/2012–30/09/2012,

e.g. before implementation of hTEE) was used. Exclusion

criteria were: (a) age less than 18 years, (b) use of pul-

monary artery catheter and (c) incomplete medical records.

In addition to comparing morphometric, demographic and

operative data, we evaluated (a) the feasibility (=ease of

insertion and technical operation) of hTEE, (b) its utility as

a hemodynamic monitor: amount and frequency of hemo-

dynamic evaluations per patient, use and cumulative doses

of catecholamines in the first week after extending hemo-

dynamic monitoring, postoperative lactate time course, net

fluid balance of the subsequent three postoperative days

(POD), and (c) overall in-hospital mortality.

The ClariTEE� probe (Imacor, New York, USA) is a

single use, miniaturized, single-plane (angle = 0�), two-dimensional transesophageal probe, which was orally

inserted in the patients esophagus and remained up to 72 h

in situ for continuously available (‘‘on demand’’) use (as

approved by the Federal Drug Agency) (Fig. 1). The probe

has a flexible tip providing ante- and retroflexion, and was

connected to a standard echocardiographic system (Zura,

Imacor, New York, USA) including standard recording

capabilities (one loop consist of approximately five ECG

cycles), provided by the company (http://imacorinc.com/

htee/products/zura-evo-1-imaging-system.html). Two-di-

mensional measurements, e.g. left ventricular end-diastolic

dimension (LVEDD) and pericardial effusion, and color

Doppler mapping were possible.

During implementation of this transesophageal mono-

plane probe into clinical routine, residents of our ICU

received a training session of approximately 6 h on this

device in vivo and on a hTEE simulator under supervision

of a team of certified echocardiographers (EACVI/EACTA

Adult TEE accreditation and/or national certification by the

German Society of Anesthesiology and Intensive Care

Medicine)—available for 24 h 7 days a week. In addition,

hTEE loops presenting specific hemodynamic conditions

were shown on computer. Residents were trained to obtain

the three most important two-dimensional hTEE views to

determine hemodynamics: (a) transgastric short axis view

(TG SAX) to evaluate global systolic left ventricular (LV)

function, paradoxical septal motion, and pericardial effu-

sion; (b) midesophageal four chamber view (4C) to eval-

uate global systolic biventricular morphology/function,

paradoxical septal motion, mitral valve morphology, and

pericardial effusion; and (c) midesophageal superior vena

cava (SVC) view to evaluate volume responsiveness and

aortic valve morphology/function [17]. A complete exam-

ination was defined to consist of these three views. After

each examination residents had to complete a report with

their qualitative results: (1) global systolic function of the

left ventricle (LV): normal, slightly/moderately/severely

reduced; (2) systolic function of the right ventricle: normal,

reduced; (3) RV/LV-Index: normal, moderately/severely

dilated [22]; (4) position and mobility of the interatrial

septum (IAS): (hyper-)mobile, centered, right- or leftward

shift [23]; (5) position/motion of the interventricular sep-

tum: normal, paradoxical motion; (6) signs of hypov-

olemia: kissing papillary muscles, small cardiac chamber

areas, (hyper-)mobile IAS, collapse of SVC under

mechanical ventilation [24]; (7) presence of pericardial

effusion with potential signs of cardiac tamponade. Certi-

fied echocardiographers then reviewed findings and inter-

pretations of ICU residents. Additionally, overall image

quality was evaluated by the ICU residents as optimal,

adequate (not optimal but sufficient for hemodynamic

guidance), or inadequate and was further reviewed by

certified echocardiographers. ICU residents then had to

propose a therapy based on their findings according to an

institutional algorithm (Fig. 2). In case of unexpected

findings and/or difficulties in interpretation of the gained

images a cardiologist and/or a certified echocardiographer

had to be called to perform a multiplane TEE (‘‘seek expert

help’’). Patients who were monitored with transpulmonary

thermodilution were treated in a similar approach: therapy

was guided by the measured parameters (cardiac index,

Fig. 1 Comparison of an hTEE (blue) and a conventional multiplane TEE probe (black)

Int J Cardiovasc Imaging (2015) 31:1327–1335 1329

123

systemic vascular resistance, pulmonary artery pressure,

etc.) according to institutional standards guided by the

German S3 guidelines [20].

For informational purposes, cardiopulmonary bypass

(CPB) and anesthesia management were performed

according to our standard operating procedures [25]. Nor-

mothermic CPBwas established with a non-pulsatile flow of

2.5 l min-1 m2 and a mean arterial pressure[60 mmHg.

Cardioplegic arrest was induced and maintained by inter-

mittent administration of antegrade warm potassium enri-

ched blood [26]. After chest closure, the patient was

transferred intubated and mechanically ventilated (pressure-

controlled mode) to ICU. Patients were kept sedated with

propofol (1–3 mg kg-1 h-1) and opioid bolus administra-

tion until cardiopulmonary stabilitywas achieved, chest tube

drainage was insignificant (\100 ml/h), and the patient was

judged to be extubated. If mechanical ventilation was

required for C12 h, analgesic sedation was switched to

midazolam 0.01–0.2 mg kg-1 h-1 combined with sufen-

tanil 0.15–0.7 lg kg-1 h-1, and weaning from mechanical

ventilation was performed according to the standard

operating procedures at our hospital [27]. Further therapy

was based on actual medical standards.

Results are expressed as mean ± standard deviation

(SD), median ± interquartile range (IQR) or percentage, as

appropriate. Normality of continuous variables was checked

with the Kolmogorov–Smirnov test. The exact Mann–

Whitney U-test was used to analyze differences between

groups. The relative frequencies of variables were analyzed

by the exact Chi square test. Non-inferiority of guiding

norepinephrine therapy was based on the on the used

cumulative doses of norepinephrine in the first week after

extending hemodynamic monitoring using hTEE or

transpulmonary thermodilution and was tested by means of

the one-sided Schuirmann-test with an inferiority margin of

‘‘0.3 9 mean (control)’’. p\ 0.05 was considered statisti-

cally significant. All tests should be understood as consti-

tuting exploratory data analysis, such that no adjustments

for multiple tests have been made. Statistics were per-

formed using SPSS 20.0 software (IBM Corporation,

Armonk, New York, USA) and EquivTest 2.0 Copyright�2001 Statistical Solutions Ltd. Cork Ireland.

Fig. 2 Institutional echocardiography-based management-algorithm

1330 Int J Cardiovasc Imaging (2015) 31:1327–1335

123

Results

18 patients were eligible according to the aforementioned

criteria during the study period and were thus monitored

with hTEE (hTEE group). These patients were retrospec-

tively case-controlled matched based on their SAPS-II

admission score on ICU (score ± 5) to 18 patients moni-

tored with transpulmonary thermodilution before hTEE

implementation (control group).

Basic patient characteristics and surgical data are pre-

sented in Table 1. There were no significant differences in

preoperative functional status, e.g. NYHA classification,

surgical procedures, or other comorbidities between

groups. Concerning the nature of valve surgery (VR)

patients with reconstructive, replacement or redo of the

aortic valve due to aortic stenosis and/or insufficiency and/

or endocarditis were included.

ICU residents at the first attempt in all patients blindly

inserted the hTEE probe. Image quality was judged to be

adequate to guide hemodynamic therapy or better in all

patients (adequate: n = 11, 61 %; optimal: n = 7, 39 %).

Image quality was never inadequate and we never had to

proceed to a conventional multiplane TEE based on hTEE

findings. In 4 patients (22 %) only 2 of the 3 views could

be obtained (no TG SAX: n = 3, no SVC: n = 1), how-

ever, these missing views were not assessed to have any

further influence on clinical decision-making. Therefore all

studies were rated to be complete. In addition, supervisors

were also not able to obtain these missing views and their

interpretations were equal with those of the residents.

30 ± 20 hTEE loops were recorded per patient with a

mean duration of probe insertion of 26.2 ± 17.6 h. This

resulted in approximately ten complete hTEE examinations

per patient, one every 2.6 h. In the control group,

extravascular lung water index (EVLWI) as a surrogate

parameter for the frequency of transpulmonary thermodi-

lutions was determined an average of 9 times per patients

in a 3 day period resulting in approximately one complete

examination every 8 h.

Results of the hTEE examination changed the current ther-

apy in nearly all cases (n = 16, 89 %): (1) administration of

levosimendan due to a severely reduced left ventricular func-

tion (n = 10, 56 %), (2) supporting right ventricular function,

i.e. administration of iloprost and/or PDE-III-inhibitors and/or

levosimendan, due to new/unexpected postoperative right heart

failure (n = 5, 28 %) (Fig. 2) (supplementary videos), and (3)

re-operation due to pericardial tamponade (n = 1, 6 %). The

first documented transpulmonary thermodilution led to a

change in current therapy in 44.4 % (n = 8): (a) volume

administration (n = 6) and (b) adding PDE-III-inhibitor

(n = 2). In addition, interpretation of the first transpulmonary

thermodilution parameters never triggered administration of

levosimendan (Fig. 3).

7 patients in the control group and only 3 patients in the

hTEE group died in hospital, but the difference did not

reach statistical significance (p = 0.264). Data on the

postoperative management in survivors (hTEE: n = 15;

control: n = 11) are presented in Table 2. Maximum

arterial lactate level and its decline in the observed post-

operative course were comparable in both groups. Net fluid

balance in the first three postoperative days was not sig-

nificantly different between groups. However, the cumu-

lative dose of epinephrine in the first week after extending

hemodynamic monitoring was significantly reduced

(p = 0.034) along with a significantly increased frequency

of levosimendan administration (p = 0.047) in the hTEE

group. There was a non-significant trend towards a lower

daily cumulative dose of enoximone in the hTEE group

(p = 0.051). Finally, hTEE was non-inferior to the control

group in guiding norepinephrine treatment (p = 0.038).

Discussion

The main findings of this retrospective, single center

analysis were that postoperative hTEE monitoring after

cardiac surgery is feasible and immediately influences

hemodynamic therapy and patient management.

After a short and intensive training programme, residents

of our ICU were able to achieve adequate or optimal quality

of obtainable images in all cases comparable to a previous

study [17]. In 22 % of the patients only two of the three

hTEE views could be acquired. However, in face of

hemodynamic guidance the missing views were not rated to

Table 1 Morphometric and demographic data and surgical

procedures

Control

(n = 18)

hTEE

(n = 18)

P value

Age (years) 69 ± 11 72 ± 9 0.389

Weight (kg) 77 ± 14 80 ± 16 0.521

Height (m) 1.73 ± 0.9 1.72 ± 0.8 0.621

Sex (men/women) 15/3 15/3 1.000

SAPS-II ICU admission 47 ± 20 49 ± 21 1.000

Procedure (n)

CABG 10 11 0.735

VR 11 6 0.095

CABG ? VR 4 1 0.148

Ventricle Rupture 0 1 0.310

NYHA III/IV (patients) 9 8 0.738

Coronary artery disease 14 15 0.674

Atrial fibrillation 10 9 0.738

Pulmonary arterial hypertension 6 6 1.000

Data are expressed as mean ± SD, numbers or percentage

Int J Cardiovasc Imaging (2015) 31:1327–1335 1331

123

have any further influence on clinical decision-making. This

is in line with a previous prospective trial in 94 ventilated

critically ill patients where image quality allowed hemo-

dynamic monitoring in 85 % [16]. Furthermore, the tech-

nical limitations of the small, monoplane hTEE probe were

the main cause for an overall lower image quality image

quality compared to a conventional multiplane probe in this

retrospective analysis [16]. This may be caused by (a) the

small, more flexible probe establishing too less surface

contact area and (b) the inability to rotate the probe

resulting in suboptimal cross-sections. In particular, at

times the lateral wall of the left ventricle was poorly visu-

alized in the midesophageal four chamber view, but always

optimal in the transgastric short axis view. However, image

quality was never inadequate for guiding hemodynamic

optimization. Indeed, residents of our department felt

quickly familiar with the probe focusing on only three

views and the possibility to frequently repeat the exami-

nation. Nevertheless, owing to these technical limitations, a

comprehensive echocardiographic evaluation cannot be

conducted with the ClariTEE� probe. Therefore, in case of

unexpected findings a multiplane TEE has to be performed

according to our institutional algorithm (Fig. 2: ‘‘Seek

expert help’’). This was never the case in this study. In

addition, we did not observe any harmful event related to

probe insertion in this retrospective analysis [28]. Espe-

cially, we saw no thermal injury since by design, imaging is

‘‘frozen’’ (the system is off) and pressure is removed (no

flexion) between two examinations (mean time interval

2.6 h).

Fig. 3 Right heart failure detected by hTEE: Left dilated SVC; Middle left ventricular hypovolemia, normal global systolic left ventricular

function, paradoxical septal motion; Right right ventricular dilation, severely reduced systolic right ventricular

Table 2 Postoperative

hemodynamic parameters in

survivors during the observation

period

Control

(n = 11)

hTEE

(n = 15)

p value

Norepinephrineaverage (mg/kg/d) 0.16 ± 0.08 0.13 ± 0.11 0.311

Patients on norepinephrine (n) 10 15 0.234

Epinephrineaverage (mg/kg/d)* 0.04 ± 0.02 0.02 ± 0.02 0.034

Patients on epinephrine (n) 9 13 0.735

Levosimendanaverage (mg/kg/d) 0.05 ± 0.02 0.04 ± 0.01 0.811

Patients on levosimendan (n)* 3 10 0.047

Enoximoneaverage (mg/kg/d) 1.42 ± 0.56 0.91 ± 0.50 0.051

Patients on enoximone (n) 9 11 0.612

Net fluid balance

POD 1 ?2104 ± 2045 ?2143 ± 1214 0.959

POD 2 ?542 ± 1514 ?515 ± 1829 1.000

POD 3 -327 ± 2124 ?170 ± 1543 0.760

Lactatemax (mg/dl) 86 ± 34 86 ± 53 0.878

Interval ‘‘Lactatemax – Lactate\20mg/dl’’ (h) 13 ± 7 14 ± 8 0.936

Data are expressed as mean ± SD or numbers

POD postoperative day

* Significant differences between groups

1332 Int J Cardiovasc Imaging (2015) 31:1327–1335

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As early as 1998 Benjamin et al. [29] demonstrated that

an additional multiplane transesophageal echocardiography

performed by intensivists changed pre-exam hemodynamic

therapy based on pulmonary artery catheter findings in

[50 % of patients. This was especially true in the case of

reduced left ventricular contractility. In the present study,

interpretation of hTEE findings after probe insertion pro-

voked changes of the current therapy in 89 % of patients.

Observers mostly reported echocardiographic findings

consistent with refractory left and/or right ventricular

failure due to chronic heart insufficiency, leading them to

administer levosimendan as ultima ratio add-on medication

[30]. This resulted in a significant reduction in the cumu-

lative dose of epinephrine. In addition, the cumulative dose

of enoximone was non-significantly reduced; however, this

may be explained in part because we do not administer

levosimendan and enoximone simultaneously in our ICU,

based on their pharmacodynamic and -kinetic profiles [31].

Furthermore, we did not observe an increase in the fre-

quency and dose of norepinephrine in the hTEE group

despite vasodilating properties of levosimendan [32]. This

is consistent with a previous study demonstrating that

levosimendan treatment did not lead to an increase in

norepinephrine when goal-directed volume therapy is

applied at the same time [30].

Interestingly, hTEE monitoring detected new and/or

clinically unexpected right ventricular (RV) dysfunction

[19, 33, 34] in approximately one-third of the patients,

comparable to a previous study [14]. Fletcher et al. [19]

also detected even more new right ventricular failure

(67.6 %) in ventilated patients with severe cardiogenic

shock requiring hemodynamic support using hTEE. Also,

one pericardial tamponade by monoplane hTEE was

detected in a very early postoperative time frame with

consequent re-operation [35–39]. In accord with the mean

duration of hTEE probe insertion [17], our results empha-

size the role of cardiac visualization early in the postop-

erative course in order to detect (new) cardiac dysfunction,

i.e. especially RV failure, optimize hemodynamics and

improve patients management [11, 16]. In this context, it is

worth noticing that we observed a non-significant trend

towards improved in-hospital mortality in the hTEE group.

We therefore conclude that the implementation of hTEE

monitoring into clinical practice following an approxi-

mately 6-h teaching session demonstrates that a focused

echocardiographic approach is feasible and sufficient to

enable physicians optimizing hemodynamics [40–43].

We did not detect a difference in the amount of volume

that has been administered between both groups. It may be

that hTEE monitoring only helps in detecting the right time

point when to administer volume, especially when atrial

fibrillation [8, 44–46] and/or right heart dysfunction are

present. In this context it has been shown that concomitant

tricuspid regurgitation is associated with underestimation

of cardiac output measured by thermodilution [47]. In

addition, clinically used parameters to estimate volume

responsiveness seem to be unreliable in patients with right

heart dysfunction [48, 49]. Finally, hTEE monitoring was

non-inferior to standard patient care in guiding nore-

pinephrine treatment.

This study stands out for its clinical approach, and as

such it has some limitations. As with all retrospective

studies, our analysis was limited by the variables available

in routine patient care. First, the number of patients ana-

lyzed in this study may also be regarded as relatively small.

In addition, EVLWI as a surrogate for the frequency of

transpulmonary thermodilutions might be inadequate in

patients with sinus rhythm and continuous pulse contour

analysis. However, there may exist some clinical scenarios

in which testing for validity of continuous pulse contour

analysis is still missing up to date. In this context it is

important to mention that C50 % of the patients of both

groups presented with atrial fibrillation (AF) preoperatively

or developed AF postoperatively. These findings represent

our first clinical experience with a new interesting device

during its implementation into daily routine. In contrast to

conventional hemodynamic monitors, the advantage of

hTEE might be the frequent ‘‘on demand’’ visualization of

the heart in combination with the here presented hemody-

namic optimization algorithm. Secondly, one might assume

that patients in the hTEE group were sicker and therefore

received significantly more often levosimendan. However,

patients functional status, all other comorbidities and their

clinical status upon arrival on ICU were comparable, and

all patients suffered sustained, life-threating hemodynamic

instability after cardiac surgery. Here, hTEE findings in

postoperative cardiac surgery patients lead to a change in

therapy in nearly all cases. Therefore, despite limitations of

its case-controlled matched-pairs approach, this study

clearly demonstrated the benefit of a focused trans-

esophageal echocardiography early in the postoperative

course if hemodynamic instability is present. Thirdly,

because assessment of volume responsiveness, the clear-

ance of lactate and the decrease in catecholaminergic

support is a compound of several factors and physician

expertise, the here presented impact of hTEE monitoring

has to be interpreted on that condition. However, there is a

need for individualized therapeutic strategies and algo-

rithms based on physiology [50, 51].

In conclusion, this retrospective analysis revealed a

beneficial influence of hTEE monitoring on the postoper-

ative management of cardiac surgery patients. Despite a

short training session, ICU residents achieved at least

adequate image quality to guide hemodynamic therapy.

hTEE monitoring is clinically feasible and can simply be

implemented into daily routine. It is not inferior to standard

Int J Cardiovasc Imaging (2015) 31:1327–1335 1333

123

patient care in guiding norepinephrine therapy. Besides one

urgent re-operation due to pericardial tamponade, hTEE

monitoring seemed to influence hemodynamic manage-

ment in patients with postoperative low cardiac output

syndrome. Finally, hTEE monitoring was useful in the

diagnosis and management of unexpected postoperative

right heart failure. Further prospective, randomized trials

are warranted to investigate the capabilities of this new

device.

Acknowledgments This study was performed within an institu-

tional Grant from Charite – Universitatsmedizin Berlin. ImaCor

provided the echocardiographic system (Zura, Imacor, New York,

USA) and the ClariTEE� probes without charge for this study, the

company provided no further financial support.

Conflict of interest S.T. received funding for experimental research

from B. Braun and honoraria for lectures from Edwards and Car-

inopharm. C.S. received (a) funding for research from the following

companies and societies: Abbott, Aspect, Baxter, Care Fusion, Del-

tex, Fresenius, Grunenthal, Hutchinson, Kohler Chemie, MSD, MCN,

Novartis, Pajunk, Pulsion, Roche, Sysmex, University Hospital Sta-

vanger, Argus, BDA, BMBF, DKH, DLR, German Research Society,

GIZ, Charite, Stifterverband, and (b) honoraria for lectures and travel/

accommodations/meeting expenses unrelated to activities listed from

Abbott, Essex Pharma, GSK, Bispebjerg Hospital, Aspect, and

(c) expert testimony from the ethical committee Vienna Faculty of

Medicine. J.P.B. received honoraria for lectures from Edwards, Car-

inopharm, Abbott, Orion and Pfizer. M.S. received funding for

research from Edwards Life Sciences, The Medicines Company and

Pulsion, honoraria for lectures from Edwards and Pulsion. For the

remaining authors none conflict of interests were declared.

References

1. Pearse R, Dawson D, Fawcett J, Rhodes A, Grounds RM et al

(2005) Early goal-directed therapy after major surgery reduces

complications and duration of hospital stay. A randomised,

controlled trial [ISRCTN38797445]. Crit Care 9:R687–R693

2. Hamilton MA, Cecconi M, Rhodes A (2011) A systematic review

and meta-analysis on the use of preemptive hemodynamic

intervention to improve postoperative outcomes in moderate and

high-risk surgical patients. Anesth Analg 112:1392–1402

3. Gan TJ, Soppitt A, Maroof M, el-Moalem H, Robertson KM et al

(2002) Goal-directed intraoperative fluid administration reduces

length of hospital stay after major surgery. Anesthesiology

97:820–826

4. Grocott MPW, Mythen MG, Gan TJ (2005) Perioperative fluid

management and clinical outcomes in adults. Anesth Analg

100:1093–1106

5. Rivers E, Nguyen B, Havstad S, Ressler J, Muzzin A et al (2001)

Early goal directed therapy in the treatment of severe sepsis and

septic shock. N Engl J Med 345:1368–1377

6. Futier E, Constantin JM, Petit A, Chanques G, Kwiatkowski F

et al (2010) Conservative vs restrictive individualized goal-di-

rected fluid replacement strategy in major abdominal surgery: a

prospective randomized trial. Arch Surg 145:1193–1200

7. Della Rocca G, Pompei L (2011) Goal-directed therapy in

anesthesia: any clinical impact or just a fashion? Minerva

Anestesiol 77:545–553

8. McGee WT, Raghunathan K (2013) Physiologic goal-directed

therapy in the perioperative period: the volume prescription for

high-risk patients. J Cardiothorac Vasc Anesth 27:1079–1086

9. Practice guidelines for perioperative transesophageal echocar-

diography (2010) An updated report by the American Society of

Anesthesiologists and the Society of Cardiovascular Anesthesi-

ologists Task Force on Transesophageal Echocardiograph.

Anesthesiology 112:1084–1096

10. Giglio M, Dalfino L, Puntillo F, Rubino G, Marucci M et al

(2012) Haemodynamic goal-directed therapy in cardiac and

vascular surgery. A systematic review and meta-analysis. Interact

CardioVasc Thorac Surg 15:878–887

11. Aya HD, Cecconi M, Hamilton M, Rhodes A (2013) Goal-di-

rected therapy in cardiac surgery: a systematic review and meta-

analysis. Br J Anaesth 110:510–517

12. Geisen M, Spray D, Fletcher N (2014) Echocardiography-based

hemodynamic management in the cardiac surgical intensive care

unit. J Cardiothorac Vasc Anesth 28:733–744

13. Wagner CE, Bick JS, Webster BH, Selby JH, Byrne JG (2012)

Use of a miniaturized transesophageal echocardiographic probe

in the intensive care unit for diagnosis and treatment of a

hemodynamically unstable patient after aortic valve replacement.

J Cardiothorac Vasc Anesth 26:95–97

14. Maltais S, Costello WT, Billings FTt, Bick JS, Byrne JG et al

(2013) Episodic monoplane transesophageal echocardiography

impacts postoperative management of the cardiac surgery patient.

J Cardiothorac Vasc Anesth 27:665–669

15. Haglund NA, Maltais S, Bick JS, Costello W, Keebler M et al

(2014) Hemodynamic transesophageal echocardiography after

left ventricular assist device implantation. J Cardiothorac Vasc

Anesth 28:1184–1190

16. Vieillard-Baron A, Slama M, Mayo P, Charron C, Amiel JB et al

(2013) A pilot study on safety and clinical utility of a single-use

72-hour indwelling transesophageal echocardiography probe.

Intensive Care Med 39:629–635

17. Cioccari L, Baur HR, Berger D, Wiegand J, Takala J et al (2013)

Hemodynamic assessment of critically ill patients using a

miniaturized transesophageal echocardiography probe. Crit Care

17:R121

18. Cavarocchi NC, Pitcher HT, Yang Q, Karbowski P, Miessau J

et al (2013) Weaning of extracorporeal membrane oxygenation

using continuous hemodynamic transesophageal echocardiogra-

phy. J Thorac Cardiovasc Surg 146:1474–1479

19. Fletcher N, Geisen M, Meeran H, Spray D, Cecconi M (2015)

Initial clinical experience with a miniaturized transesophageal

echocardiography probe in a cardiac intensive care unit. J Car-

diothorac Vasc Anesth. doi:10.1053/j.jvca.2014.09.016

20. Carl M, Alms A, Braun J, Dongas A, Erb J et al (2010) S3

guidelines for intensive care in cardiac surgery patients: hemo-

dynamic monitoring and cardiocirculary system. Ger Med Sci 8.

doi:10.3205/000101

21. Cheitlin MD, Armstrong WF, Aurigemma GP, Beller GA, Bier-

man FZ et al (2003) ACC/AHA/ASE 2003 Guideline Update for

the Clinical Application of Echocardiography: summary article.

A report of the American College of Cardiology/American Heart

Association Task Force on Practice Guidelines (ACC/AHA/ASE

Committee to Update the 1997 Guidelines for the Clinical

Application of Echocardiography). J Am Soc Echocardiogr

16:1091–1110

22. Kukucka M, Stepanenko A, Potapov E, Krabatsch T, Redlin M

et al (2011) Right-to-left ventricular end-diastolic diameter ratio

and prediction of right ventricular failure with continuous-flow

left ventricular assist devices. J Heart Lung Transplant 30:64–69

23. Kusumoto FM, Muhiudeen IA, Kuecherer HF, Cahalan MK,

Schiller NB (1993) Response of the interatrial septum to

transatrial pressure gradients and its potential for predicting

1334 Int J Cardiovasc Imaging (2015) 31:1327–1335

123

pulmonary capillary wedge pressure: an intraoperative study

using transesophageal echocardiography in patients during

mechanical ventilation. J Am Coll Cardiol 21:721–728

24. Vieillard-Baron A, Chergui K, Rabiller A, Peyrouset O, Page B

et al (2004) Superior vena caval collapsibility as a gauge of

volume status in ventilated septic patients. Intensive Care Med

30:1734–1739

25. Spies C, Kastrup M, Kerner T, Melzer-Gartzke C, Zielke H, Kox

W (2013) SOPs in Anasthesiologie und Schmerztherapie: Alle

relevanten Standards und Techniken fur die Klinik. 1 ed. Thieme

26. Calafiore AM, Teodori G, Di Giammarco G, Bosco G, Mezzetti

A et al (1994) Intermittent antegrade cardioplegia: warm blood vs

cold crystalloid. A clinical study. J Cardiovasc Surg 35:179–184

27. Spies C, Kastrup M, Kerner T, Melzer-Gartzke C, Zielke H, Kox

W (2013) SOPs in Intensivmedizin und Notfallmedizin: Alle rel-

evanten Standards und Techniken fur die KLinik, 1 ed. Thieme

28. Hilberath JN, Oakes DA, Shernan SK, Bulwer BE, D’Ambra MN

et al (2010) Safety of transesophageal echocardiography. J Am

Soc Echocardiogr 23:1115–1127

29. Benjamin E, Griffin K, Leibowitz AB, Manasia A, Oropello JM

et al (1998) Goal-directed transesophageal echocardiography

performed by intensivists to assess left ventricular function:

comparison with pulmonary artery catheterization. J Cardiothorac

Vasc Anesth 12:10–15

30. Erb J, Beutlhauser T, Feldheiser A, Schuster B, Treskatsch S et al

(2014) Influence of levosimendan on organ dysfunction in

patients with severely reduced left ventricular function under-

going cardiac surgery. J Int Med Res 42:750–764

31. Nieminen MS, Fruhwald S, Heunks LM, Suominen PK, Gordon

AC et al (2013) Levosimendan: current data, clinical use and

future development. Heart Lung Vessel 5:227–245

32. Toller WG, Stranz C (2006) Levosimendan, a new inotropic and

vasodilator agent. Anesthesiology 104:556–569

33. Haddad F, Couture P, Tousignant C, Denault AY (2009) The

right ventricle in cardiac surgery, a perioperative perspective: II.

Pathophysiology, clinical importance, and management. Anesth

Analg 108:422–433

34. Vlahakes GJ (2005) Right ventricular failure following cardiac

surgery. Coron Artery Dis 16:27–30

35. Imren Y, Tasoglu I, Oktar GL, Benson A, Naseem T et al (2008)

The importance of transesophageal echocardiography in diagno-

sis of pericardial tamponade after cardiac surgery. J Card Surg

23:450–453

36. Kuvin JT, Harati NA, Pandian NG, Bojar RM, Khabbaz KR

(2002) Postoperative cardiac tamponade in the modern surgical

era. Ann Thorac Surg 74:1148–1153

37. Bommer WJ, Follette D, Pollock M, Arena F, Bognar M et al

(1995) Tamponade in patients undergoing cardiac surgery: a

clinical-echocardiographic diagnosis. Am Heart J 130:1216–1223

38. Weitzman LB, Tinker WP, Kronzon I, Cohen ML, Glassman E

et al (1984) The incidence and natural history of pericardial

effusion after cardiac surgery—an echocardiographic study.

Circulation 69:506–511

39. Hirose H, GuptaS Pitcher H, Miessau J, Yang Q et al (2014)

Feasibility of diagnosis of postcardiotomy tamponade by minia-

turized transesophageal echocardiography. J Surg Res

190:27276–27279

40. Cholley BP, Vieillard-Baron A, Mebazaa nA (2006) Echocar-

diography in the ICU: time for widespread use! Intensive Care

Med 32:9–10

41. Manasia AR, Nagaraj HM, Kodali RB, Croft LB, Oropello JM

et al (2005) Feasibility and potential clinical utility of goal-di-

rected transthoracic echocardiography performed by noncardiol-

ogist intensivists using a small hand-carried device (SonoHeart)

in critically ill patients. J Cardiothorac Vasc Anesth 19:155–159

42. Jensen MB, Sloth E, Larsen KM, Schmidt MB (2004)

Transthoracic echocardiography for cardiopulmonary monitoring

in intensive care. Eur J Anaesthesiol 21:700–707

43. Kaul S, Stratienko AA, Pollock SG, Marieb MA, Keller MW et al

(1994) Value of two-dimensional echocardiography for deter-

mining the basis of hemodynamic compromise in critically ill

patients: a prospective study. J Am Soc Echocardiogr 7:598–606

44. Wittkowski U, Spies C, Sander M, Erb J, Feldheiser A et al

(2009) Haemodynamic monitoring in the perioperative phase.

Available systems, practical application and clinical data. Der

Anaesthesist 58(764–778):780–786

45. Habicher M, Perrino A Jr, Spies CD, von Heymann C, Wit-

tkowski U et al (2011) Contemporary fluid management in car-

diac anesthesia. J Cardiothorac Vasc Anesth 25:1141–1153

46. Ostergaard M, Nilsson LB, Nilsson JC, Rasmussen JP, Berthelsen

PG (2005) Precision of bolus thermodilution cardiac output

measurements in patients with atrial fibrillation. Acta Anaesthe-

siol Scand 49:366–372

47. Balik M, Pachl J, Hendl J (2002) Effect of the degree of tricuspid

regurgitation on cardiac output measurements by thermodilution.

Intensive Care Med 28:1117–1121

48. Wyler von Ballmoos M, Takala J, Roeck M, Porta F, Tueller D

et al (2010) Pulse-pressure variation and hemodynamic response

in patients with elevated pulmonary artery pressure: a clinical

study. Crit Care 14:R111

49. Ranucci M, Pazzaglia A, Tritapepe L, Guarracino F, Lupo M et al

(2009) Fluid responsiveness and right ventricular function in

cardiac surgical patients. A multicenter study. HSR Proc Inten-

sive Care Cardiovasc Anesth 1:21–29

50. Zhang Z, Ni H, Qian Z (2015) Effectiveness of treatment based

on PiCCO parameters in critically ill patients with septic shock

and/or acute respiratory distress syndrome: a randomized con-

trolled trial. Intensive Care Med 41:444–451

51. Boulain T, Cecconi M (2015) Can one size fit all? The fine line

between fluid overload and hypovolemia. Intensive Care Med

41:544–546

Int J Cardiovasc Imaging (2015) 31:1327–1335 1335

123