Download Extracorporeal membrane oxygenation in 108 patients with low

DOI: 10.5301/IJAO.2011.7727
Int J Artif Organs 2011 ; 34 ( 4): 365- 373
ORIGINAL ARTICLE
Extracorporeal membrane oxygenation in 108 patients
with low cardiac output – a single-center experience
Andres Beiras-Fernandez*, Marcus-André Deutsch*, Sandra Kainzinger, Ingo Kaczmarek, Ralf Sodian,
Peter Ueberfuhr, Bruno Meiser, Michael Schmoeckel, Bruno Reichart, Paolo Brenner
Department of Cardiac Surgery, Grosshadern University Hospital, Ludwig-Maximilians-University (LMU) Munich Germany
*A Beiras-Fernandez and M-A Deutsch contributed equally to this work
ABSTRACT
Background: For short-term ventricular and pulmonary support the extracorporeal membrane oxygenation (ECMO) system using the Bio-Medicus centrifugal pump (Medtronic®, Minneapolis, MN, USA)
was applied in 108 patients with cardiac low-output.
Methods: From December 1996 to July 2006 the ECMO was implanted in 108 patients (73 adult, mean
age: 49.3±18.0 yrs and 35 children, mean age: 1.3 ± 2.7 yrs) with mostly postcardiotomy cardiac low
output. The surgical procedures included congenital heart surgery (n=35), heart transplantation (HTx)
(n=21), coronary artery bypass operation (CABG) and/or valvular operation (n=33), other operations
(n=6) and 13 patients with ECMO support for bridge to recovery.
Results: The mean supporting time was 5.1±5.6 days. Overall, 30-day-survival was 40.2%. Best survival rates were seen after congenital heart surgery (24/35, 65.7%) and after HTx (9/21, 42.9%); the
worst rates were in the group of CABG and/or valvular operations (5/33, 15.2%), only ECMO support
(3/13, 23.1%) and other operations (1/6, 16.7%). Fifty-four patients died while supported by ECMO,
15 were weaned from ECMO but died in hospital, 39 patients were weaned and survived. Causes
of death were multi-organ failure (40.6%), bleeding (23.2%), persistent cardiac low output (21.7%),
thrombembolic events (8.7%), and graft failure (5.8%). Markers for adverse outcome were identified as
older age, high body weight, increased AST/GOT levels, and lower thrombocyte count in adults; and
as higher levels of serum creatinine in pediatric patients.
Conclusions: ECMO support showed best results in pediatric patients after congenital heart surgery
and in patients after HTx in contrast to multimorbid, older patients with often irreversible myocardial
damage.
KEY WORDS: Low cardiac output, ECMO, VAD, Acute heart failure, Heart surgery
Accepted: January 24, 2011
INTRODUCTION
Although surgical techniques and methods for myocardial protection have been continuously improved over the
last few decades, low cardiac output is seen frequently
in the perioperative phase during and after weaning from
cardiopulmonary bypass (CPB) (1, 2). The etiology of car-
diac low-output is often multifactorial but includes myocardial ischemia during cross-clamping, reperfusion injury,
cardioplegia-induced myocardial dysfunction, systemic
inflammatory response syndrome, and pre-existing myocardial damage (3). The majority of these patients can successfully be managed by intensified inotropic drug therapy
or intra-aortic balloon counterpulsation (IABP). Neverthe-
© 2011 Wichtig Editore - ISSN 0391-3988
365
ECMO for low cardiac output syndrome
less, a small proportion of patients who are refractory to
conventional treatment need additional mechanical circulatory support postoperatively. Extracorporeal membrane
oxygenation (ECMO) is a modified form of cardiopulmonary bypass which can successfully be used to transitionally provide mechanical circulatory support in patients with
low cardiac output and pulmonary failure. The aim of this
support is to stabilize hemodynamics, to simultaneously
unload the heart in order to gain time for the recovery of
stunned myocardium, and to guarantee adequate blood
supply of the other vital organs. Distinct advantages in
this setting are rapid delivery of adequate blood flow for
unloading of the left and right ventricles, and adequate
oxygenation without the deleterious effects of high dose
inotropic medication and high-inspired oxygen, and the
possibility to regulate the systemic body temperature (4).
However, although ECMO support as a therapeutic means
in neonates and pediatric patients is well established, its
role in adults is less well scrutinized and morbidity as well
as mortality is considerable. Criteria for ECMO implantation in adults are not precisely defined. Furthermore, there
is limited knowledge and controversy about the factors
predictive of survival.
Thus, the objective of this single-center study was to review the outcome of all patients who received ECMO sup-
port for cardiac low output after cardiac surgery and to
identify measurable variables predictive of adverse events
and mortality in our patients.
PATIENTS AND METHODS
Patient population and indications for ECMO
implantation
Between December 1996 and July 2006 a total of 15662
patients underwent cardiac surgical intervention with the
use of cardiopulmonary bypass in the Grosshadern Clinic in Munich. During this time, ECMO was implanted for
mechanical circulatory support in 108 patients (mean age:
33.8±27.0 years) with low cardiac output. Overall, 73 adult
(50 male/23 female patients) and 35 pediatric patients were
connected to ECMO support after failure to be weaned
from cardiopulmonary bypass. The surgical procedures are
listed in Table I. Mean age of adult patients was 49.3±18.0
years and 1.3±2.7 in pediatric patients, mean duration in
days of ECMO support was 4.4±4.0 in adult and 7.0±8.0
in pediatric patients. A number of 36 patients (49.3%)
were either on intra-aortic balloon counterpulsation before
TABLE I - PATIENT DEMOGRAPHICS AND SURGICAL DATA (N = 108)
Parameter
Adult Patients
Pediatric Patients
Gender, male/female
Age (years)
Body weight (kg)
Height (cm)
BMI (kg/m²)
BSA (m²)
Primary indications for surgery
47/26
49.3 ± 8.0
77.6 ± 19.8
175.1 ± 9.7
25.27 ± 5.78
1.91 ± 0.22
CABG and/or valve
CABG
CABG and valve
Mitral valve
Other valve
Double valve
Post-HTx
Emergency ECMO
Others
22/13
1.3 ± 2.7
11.2 ± 6.1
78.9 ± 16.6
17.2 ± 4.1
0.41 ± 0.21
Congenital
TGA
Fallot
Norwood I
Emergency
Others
CPB time (min)
Aortic clamp time (min)
IABP (only adults) (n)
Mean ECMO duration (d)
Redo sternotomy (n)
254.3 ± 18,3
110.9 ± 14.0
36 (49.3%)
5.14 ± 5.6
43 (39.8%)
366
33 (31%)
14
6
6
6
1
21 (19%)
13 (12%)
6
© 2011 Wichtig Editore - ISSN 0391-3988
290.1 ± 22,3
110.5 ± 12.2
-
35 (32%)
9
5
5
9
7
Beiras-Fernandez et al
surgery or it was instituted in addition to ECMO support.
Mean aortic cross-clamping time was 110.9±4.0 minutes
in adults and 110.5±12.2 minutes in children. Mean bypass
time was 254.3±18.3 minutes in adults and 290.1±22.3
minutes in children.
Intraoperatively, ECMO support was considered on a caseby-case basis in patients who failed to be weaned from cardiopulmonary bypass. Patients were considered for ECMO
implantation if they had a cardiac index less than 2 l/min/
m² with systolic blood pressure of 75 mm Hg, a pulmonary
capillary wedge pressure (PCWP) of more than 20 mm Hg,
a maximum oxygen uptake of <12 ml/min/kg body weight
despite adequate filling pressures, the use of maximal inotropic pharmacological support and/or intra-aortic balloon
counterpulsation. ECMO was our first choice of mechanical support independently of associated pulmonary damage for various reasons, including the rapid implantation,
the absence of further cardial damage, and the possibility
of bridging to another VAD under elective conditions.
ECMO circuit design and patient management
The Bio-Medicus Perfusion system consisted of a Carmeda Bioactive Surface-coated circuit made of polyvinyl
tubing (Carmeda®; Vasby, Sweden), a centrifugal blood
pump (Bio-Pump, Medtronic®, Minneapolis, MN, USA:
50 cc pump head when flow <1.5 l/min; an 80 cc pump
head when flow >1.5 l/min was required), a hollow-fiber
oxygenator (Medos® Hilite 7000 LT or 2400 LT, Stolberg,
Germany), a heater/cooler unit, and an oxygen saturation/
hematocrit monitor (Medtronic®, Minneapolis, MN, USA).
All surfaces in contact with blood were heparin coated. For
safety reasons, the circuit was equipped with two oxygenators which were assembled in parallel. Cannulation was
performed via the ascending aorta and right atrium in most
patients. In patients failing to wean from CPB, the cannulas
in the right atrial (adults: 28 F Medtronic two-stage cannula; Medtronic, Minneapolis, MN, USA) and ascending aorta
(Adults: 22 F EOPA© arterial cannula; Medtronic, Minneapolis, MN, USA) were left in place and then connected to the
ECMO. The chest was mostly left open, covered by a sterile adhesive plastic or Esmarch membrane. In emergency
cases, transfemoral cannulation was used (preferred cannulae: arterial 16-18 F EOPA© arterial cannula; Medtronic,
Minneapolis, MN, US; venous: 19-21 F Biomedicus Multistage; Medtronic, Minneapolis, US). Mechanical ventilation
was continued in order to achieve oxygenation and CO2
elimination. Positive end-expiratory pressure was adjusted
to a level of 10 cm H2O for the prevention of atelectasis.
All patients were anticoagulated as follows. Heparin was
administered intravenously to maintain an activated clotting time (ACT) of 160-200 seconds (s) and a PTT of 60
to 80 s to prevent coagulation in the ECMO. Procoagulative products and platelets were administered to maintain
platelets >100-150 x 109, fibrinogen >2.0 g/l and a prothrombin time <14 s. Red packed blood cells were used
when hemoglobin level was lower than 8-9 mg/dl. In order to minimize third-space fluid accumulation in patients
with renal failure, excessive crystalloid administration was
avoided and hemofiltration was used. The hemodynamic
management was targeted to maintain a mean blood pressure level of 70-80 mm Hg. For adequate systemic circulatory support a blood flow of at least 2.0 to 2.5 l/min/m²
was warranted with a target of a mixed venous oxygen
saturation of more than 70%. Oxygen flow was gradually
adjusted as necessary to meet the oxygen requirements
according to repetitive blood gas sample measurements.
All patients were supported with the intention to wean from
ECMO.
Statistics
Patient cumulative survival was calculated using KaplanMeier analysis. Differences in actuarial survival were determined by the log-rank test. For univariate analysis of
continuous variables Student’s t-test was performed. Categorical variables are expressed as percentages and were
analyzed with the Fisher’s exact test. All analyses were performed using SPSS software (version 15.0 for Windows,
SPSS, Chicago, IL, US). A p-value <0.05 was considered
statistically significant. All parameter are expressed as
mean ± standard deviation or ± standard error of the mean
(SEM) when indicated.
RESULTS
ECMO support was required by 0.7% of all patients undergoing cardiac surgery including transplantation. The
mean supporting time was 5.1±5.6 days. In adults, mean
supporting time was 4.4±4.0 days (survivors: 6.5±4.7 days,
non-survivors: 3.8±3.7 days), in children 7.0±8.0 days (survivors: 4.6±1.8 days, non-survivors: 10.5±11.9 days).
Fifty-four patients (50%) died while supported by ECMO,
© 2011 Wichtig Editore - ISSN 0391-3988
367
ECMO for low cardiac output syndrome
Fig. 1 - Overall 30-day survival
(left). Survival based on patient age (age 0-14 vs. others:
p<0.05) (right).
Fig. 2 - Causes of death (p<0.05 in all causes of death of adults vs.
children).
while 15 (13.9%) were weaned from ECMO but died in hospital. The 30-day-survival was 40.7%, after 50 days it was
still 38.9% and after 100 days 38.0%. We documented a
total survival of 36.1% after a 1-year follow-up. After an
average of 33.5 days in the intensive care unit a total of 39
patients survived and were discharged (Fig. 1).
When looking at survival related to the primary indication
for support, best 30-day-survival was seen in the group
with congenital heart surgery (74.3%) and heart transplantation (42.9%). Worst survival rates were found in the group
of ECMO after cardiogenic shock as a means of bridge-torecovery (23.1%), and after CABG and/or valvular operations (15.2%). A separate statistical analysis of the adult
368
patients was performed: 5 patients died during the first 24
hours, 17 died the second day (during the first 24 to 48
hours), further 11 died during the first 48 to 96 hours. Only
40 adult patients could survive more than four days, 24 of
these patients died in the following days. In children, the
first patient died on the second day of ECMO support. One
child died after 48 to 96 hours. The remaining 33 children
survived more than 96 hours, while 10 died in the further
follow-up. The main cause of death was multi-organ failure (MOF) with refractory ventricular failure (40.6%) during
support. Other reasons for mortality were coagulopathyrelated profuse bleeding (23.2%), isolated persistent low
cardiac output (21.7%), thrombembolic events (8.7%), and
allograft failure (5.8%) (Fig. 2).
When comparing parameters of survivors and non-survivors in the univariate analysis we found that in adults,
patients over 60 years of age were less likely to survive
(p=0.038) (Fig. 3). The mean age of surviving patients was
16.7±21.9 years versus 43.6±24.8 years of the deceased
patients (Tab. II). The other 15 survivors in adult patients
were younger than 60 years. Other parameters which predicted an unfavorable outcome in adults were higher body
weight with the corresponding higher body surface area
(BSA). A significantly better survival (p<0.001) was evident
in patients up to 60 kg body weight (Fig. 4).
Similarly, we could not find a significant difference for the
cardiopulmonary bypass time or aortic clamp time when
comparing survivors and non-survivors. A subgroup data
analysis of 86 patients showed that in 41 (47.7 %) of these
patients the intraoperative bypass time was longer than 4
hours. Overall, 28 of these 41 died (68.3 %). Of our 45 patients with a bypass time longer than four hours, 27 (60%)
did not survive. In 16 (18.6%) of all patients, intraoperative
© 2011 Wichtig Editore - ISSN 0391-3988
Beiras-Fernandez et al
Fig. 3 - Survival rates based on adult patient body weight (kg) (body
weight 0- 60 vs. >60: p<0.05).
bypass time was longer than 6 hours. Of these patients
12 (75%) died in course of the ECMO therapy. These results cannot show a statistically significant advantage of
shorter bypass time for patient survival. The use of an IABP
also showed a trend but no significant effect on mortality
(p=0.5). Patient gender did not influence survival rates. In
adults, 21.7% of female and 22.0% of male patients survived. Within the pediatric group, 68.8% of the girls and
63.2% of the boys survived. Redo-sternotomy for bleeding was necessary in 37 adults and in 6 children. Of these
43 patients, 30 died (28 adults). No statistically significant
disadvantage for patients with redo-sternotomy could be
observed (Tab. II).
Adult patients after HTx were separately compared with the
other adult patients. Of all 21 heart transplanted adults, 9 patients survived after ECMO (42.9%). Within the other groups
of the resting 52 adult patients, only 7 survived (13.5%) after
one year. Results are shown in Figure 5 comparing outcomes
of congenital heart surgery with heart transplantation and
other groups (p=0.008). The best survival rate was seen in
the group with congenital heart surgery (24/35, 65.7%), significantly higher than after HTx (9/21, 42.9%). Both groups
had significantly better survival rates than the group with
CABG and valvular operations (5/33, 15.2%).
Univariate analysis of common laboratory markers revealed
that in adults non-survivors had mean AST/GOT levels of
656±640 IU/l after 72 hours if compared to 172±263 IU/L in
survivors (p=0.010). Platelet count after 24 and 72 hours was
significantly lower in non-survivors if compared with survivors (p=0.001 and p=0.023). For hemoglobin, bilirubin, serum
creatine kinase (CK), and creatinine no significant difference
could be observed (Tab. III). Within the pediatric group we
found a significant difference (p=0.023) in levels of creatinine
after 72 hours (0.8±0.4 m/dL in survivors, 1.3±0.8 mg/dL in
non-survivors) (Tab. III). Altogether significantly better routine
laboratory parameters could be seen in survivors.
For a better evaluation of the single factors influencing
TABLE II - SURVIVOR AND NON-SURVIVOR CHARACTERISTICS OF ADULT PATIENTS
Female gender
Age (years)
Weight (kg)
Height (cm)
BSA (m²)
Primary indication for Cardiac surgery
CABG and/or valve (n)
Post-HTx (n)
Emergency ECMO (n)
Others (n)
IABP (n/%)
Aortic clamp time (min)
CBP time (min)
Duration of support (d)
Survivors
Non-survivors
P value
5/31,3%
39.3±21.0
63±12.3
178±12.9
1.79±0.2
18/31,6 %
58.1±15.1
80±17.1
174±8.1
1.94±0.2
0.872;n.s.
0.008
0.002
0.24;n.s.
0.037
4
9
3
0
6/37.5 %
92±43
212±104
6.5±4.7
29
12
10
6
30/52,6 %
116±118
266±146
3.8±3.7
0.5;n.s.
0.504;n.s.
0.234;n.s.
0.023 .
(n.s. = not significant)
© 2011 Wichtig Editore - ISSN 0391-3988
369
ECMO for low cardiac output syndrome
TABLE III - LABORATORY VARIABLES OF SURVIVORS AND NON-SURVIVORS
All
a) Adults
Hemoglobin (g/dL)
Bilirubin (mg/dL)
Creatinine (mg/dL)
CK (IU/L)
Thrombocytes
AST/GOT (IU/L)
b) Children
hemoglobin (g/dL)
Bilirubin (mg/dL)
Creatinine (mg/dL)
CK (IU/L)
Thrombocytes
AST/GOT (IU/L)
Survivors
Non-survivors
P value
24h
72h
pre-op
24h
72h
pre-op
24h
72h
24h
72h
(G/l)
72h
24h
72h
8.8±1.7
9.3±1.2
2.6±5.3
3.4±3.4
4.4±3.5
1.8±1.1
2.0±0.9
2.1±0.8
246±4297
2931±4319
24h 87±81
82±104
1261±2499
495±587
9.1±1.4
9.3±1.3
1.8±1.6
3.8±2.2
4.1±3.4
1.5±0.5
1.7±0.5
1.9±0.7
824±911
1178±2236
147±133
133±169
215±209
172±263
8,8±1,8
9.4±1.2
2.9±6.1
3.2±3.7
4.5±3.6
1.9±1.3
2.1±1.1
2.3±0.8
2910±4739
3807±4851
72±51
57±25
1573±2775
656±640
0.466; n.s.
0.774; n.s.
0.540; n.s.
0.584; n.s.
0.765; n.s.
0.267; n.s.
0.210; n.s.
0.130; n.s.
0.108; n.s.
0.062; n.s.
0.001
0.023
0.074; n.s.
0.010
24h
72h
pre-op
24h
72h
pre-op
24h
72h
24h
72h
(G/l)
72h
24h
72h
11.3±1.7
11.5±1.1
2.8±2.4
2.9±2.3
3.5±3.7
0.8±0.5
0.9±0.5
1.0±0.6
1118±1862
528±734
24h 173±112
127±67
511±999
481±1499
11.4±1.6
11.3±1.1
2.5±2.0
2.5±1.3
2.8±2.9
0.7±0.2
0.8±0.4
0.8±0.4
1469±2250
615±819
185±110
136±56
454±903
201±272
11.0±1.8
12.0±0.9
3.5±3.3
3.6±3.4
5.0±4.8
0.9±0.8
1.2±0.7
1.3±0.8
512±557
354±520
149±118
109±85
626±1215
1072±2614
0.478;n.s.
0.062;n.s.
0.336;n.s.
0.171;n.s.
0.129;n.s.
0.173;n.s.
0.052;n.s.
0.023
0.180;n.s.
0.367;n.s.
0.386; n.s.
0.320;n.s.
0.666;n.s.
0.154,n.s.
(n.s.= not significant).
patient survival a multivariate analysis using the Cox regression model was performed. Only patients age could
be found as an independent predictive factor with better
results in young patients.
DISCUSSION
Critical hemodynamic compromise in terms of postcardiotomy myocardial dysfunction is encountered in approximately 2% to 6% of all patients undergoing routine cardiac
surgery procedures (1, 2). The majority of these patients
can be managed with intensified inotropic support and/
or short-term mechanical support with IABP. Fortunately,
more advanced circulatory assistance is necessary in only
0.2% to 1.2% of patients. Similarly, in our experience,
370
0.7% of all patients undergoing cardiac surgery including
transplant procedures required ECMO support.
ECMO is the most common form used for initial support after failure to wean from extracorporeal circulation or for delayed postoperative cardiogenic shock. In most institutions
ECMO is rapidly available, providing both emergent cardiac
and pulmonary support; it is easy to apply, and compared
to other mechanical assist devices is rather inexpensive
(3). Additionally, in contrast to VADs, ECMO can provide
pulmonary support. During postcardiotomy, low output
ECMO can be easily connected to the cannulas used for
cardiopulmonary bypass. A percutaneous transfemoral
cannulation can be set up at bedside. Consequently, fewer
bleeding complications and less sedation can be observed
if compared with VADs (6). As stated by Magovern et al,
transthoracic cannulation is preferred by virtue of the pos-
© 2011 Wichtig Editore - ISSN 0391-3988
Beiras-Fernandez et al
sibility to more effectively increase available flow rate when
compared to the femoral access. Further advantages of
central cannulation include a better unloading of the ventricles, and a reduction in the risk of peripheral vascular complications. Disadvantages of central cannulation include an
increased bleeding rate, which could be documented in
our patients in comparison to transfemoral access, without
having any relevance upon survival (7). However, several
disadvantages have to be kept in mind when considering
ECMO support. First, ECMO is not designed for long-term
support, since mobilization of the patient is heavily limited.
Moreover, patients with thoracic application of the ECMO
cannula need to be sedated and often the chest cannot be
closed. Besides, ECMO support leads to severe platelet
activation loss and dysfunction with possibilities of profound bleeding and/or stroke.
The results of our retrospective study show an overall
30-day-survival of 41% (adults: 25%, children: 74%). If
compared with results of other study groups, the variant
survival rates (22-47%) between different studies might in
part be influenced by patient selection and the doubtful
reasonable employment of ECMO as an ultima ratio therapy. The outcome of patients that were placed on ECMO
in the postoperative period is considerably better if compared with patients in whom ECMO is required to separate
them from extracorporeal circulation (8). Fiser et al tried
to establish guidelines to simplify the decision when to
discontinue ECMO support as a bridge-to-recovery. They
concluded that after 48 to 72 hours, consideration should
be given to move to an implantable long term VAD (ECMO
as a bridge-to-bridge) or to stop support, except in patients after heart transplantation (9, 10).
The duration of ECMO support in our collective was considerably longer when compared with the almost 5-day duration seen in other study groups, given that our survivors
were supported for a period of 6.5 ± 4.7 days. Our strategy
was to provide sufficient time to recover from myocardial
injury, especially in patients after HTx being supported for
6.0 ± 5.0 days.
In our patients secondary MOF was the most frequent
causes of death. In a prospective study Rastan et al
evaluated the autopsy findings of 78 patients who died
on ECMO support. Clinically unrecognized postoperative complications and unexpected causes of death were
found by autopsy in 76% and 28% of all patients, respectively, including a high incidence of venous thrombus formation and fatal events secondary to local and systemic
thrombembolic events (11). These results demonstrate that
anticoagulation during ECMO therapy is still suboptimal to
prevent thrombembolic events and avoid bleeding in patients with MOF.
Several risk factors for the postoperative mortality were
shown in the literature. They include older age (over 50
years old), extended aortic operations, shorter aortic
clamp time, shorter height, rethoracotomy, previous myocardial infarction, and lack of IABP (1, 6, 7, 12). In our study
we observed a significantly better survival of the under
60-year-old adult patients. We also observed that patients
with higher body weight and larger body surface area had
a higher risk for mortality during support. Therefore, these
patients might benefit from more advanced forms of mechanical circulatory support and could be considered for
primary VAD implantation.
ECMO support in our adult patients after cardiac transplantation had a significantly better outcome than after
other procedures. Magovern et al described the use of early post-transplant use of ECMO for providing support after
early graft failure due to pulmonary hypertension refractory
to inhaled nitric oxide and pulmonary vasodilators resulting
in right ventricular overload and dysfunction, a potentially
reversible condition (7).
ECMO support in neonatal and pediatric patients is a well
established concept and a good outcome has been described (15-18). ECMO implantation in our pediatric patients resulted in a good outcome, with 74.3% survival rate
after 30 days. The malformations of the immature myocardium result in liability to postoperative heart failure and cardiac low output (15). Balsubramanian et al described neurological complications after cardiopulmonal resuscitation,
bleeding, and cardiac arrhythmia in their pediatric patients
(18). Especially in children, increasing renal failure is seen
as a risk factor for mortality under ECMO support (19, 20).
The adverse alteration of serum creatinine in our non-survivors provides striking confirmation of this observation.
In adult non-survivors, thrombocyte counts were lower after 24 hours as well as after 72 hours. This is compatible
with higher blood loss. In pediatric patients, higher thrombocyte counts were found because of fewer bleeding complications. Due to the existence of thrombocytopenia and
thrombocyte dysfunction there is also an increased risk of
intracranial bleeding with a mortality of 92.3% (21, 22). A
reasonable level of anticoagulation, prevention of renal failure, and aggressive replacement of thrombocytes must be
aimed for. In all patients AST/GOT was massively elevated.
© 2011 Wichtig Editore - ISSN 0391-3988
371
ECMO for low cardiac output syndrome
In adult non-survivors it was even 7 times higher than in
survivors. Serum creatinine levels as a marker for renal failure were constantly elevated in adults and higher levels
were registered in non-survivors. Comparing CK of survivors with non-survivors, a trend for the benefit of survivors
could be observed (p=0.11 after 24 h, p=0.06 after 72 h).
In conclusion, several laboratory parameters can describe
the patients’ state of health and progression of MOF or
recovery. Smedira et al assessed a decreased survival rate
in older patients with higher levels of creatinine and bilirubin (12). The specific series of routine laboratory values we
have discussed above are predictive for patients prognosis, they can help to identify potential complications, and
offer guidance on how to proceed.
In the future, it will be of interest to know the extent to
which third-generation blood pumps with higher blood
flow rates and reduced contact activation of blood cells,
along with coagulation components with potentially less
systemic inflammatory response, will improve the outcome
of ECMO patients. Magnetic-levitation blood pumps deserve attention in particular since they allow the suspension of the blood impeller without any mechanical contact,
thus eliminating wear that takes place at the contact surface. They also reduce heat generation, which is crucial for
the improvement of biocompatibility properties (23).
REFERENCES
7. Magovern GJ Jr, Simpson KA. Extracorporeal membrane
oxygenation for adult cardiac support: the Allegheny experience. Ann Thorac Surg. 1999;68(2):655-661. Medline.
doi:10.1016/S0003-4975(99)00581-0
8. Muehrcke DD, McCarthy PM, Stewart RW, et al. Extracorporeal membrane oxygenation for postcardiotomy cardiogenic
shock. Ann Thorac Surg. 1996;61(2):684-691. Medline.
doi:10.1016/0003-4975(95)01042-4
9. Fiser SM, Tribble CG, Kaza AK, et al. When to discontinue
extracorporeal membrane oxygenation for postcardiotomy
support. Ann Thorac Surg. 2001;71(1):210-214. Medline.
doi:10.1016/S0003-4975(00)02340-7
10. Chou NK, Chi NH, Ko WJ, et al. Extracorporeal membrane
oxygenation for perioperative cardiac allograft failure.
ASAIO J. 2006;52(1):100-103. Medline. doi:10.1097/01.
mat.0000196514.69525.d9
11. Rastan AJ, Lachmann N, Walther T, et al. Autopsy findings in
patients on postcardiotomy extracorporeal membrane oxygenation (ECMO). Int J Artif Organs. 2006;29(12):1121-1131.
Medline.
12. Smedira NG, Moazami N, Golding CM, et al. Clinical experience with 202 adults receiving extracorporeal membrane oxygenation for cardiac failure: survival at five years. J Thorac
Cardiovasc Surg. 2001;122(1):92-102. Medline. doi:10.1067/
mtc.2001.114351
13. Combes A, Leprince P, Luyt CE, et al. Outcomes and longterm quality-of-life of patients supported by extracorporeal
1. Doll N, Kiaii B, Borger M, et al. Five-year results of 219 consecutive patients treated with extracorporeal membrane
oxygenation for refractory postoperative cardiogenic shock.
Ann Thorac Surg. 2004;77(1):151-157. Medline. doi:10.1016/
S0003-4975(03)01329-8
2. Noon GP, Lafuente JA, Irwin S. Acute and temporary ventricular support with BioMedicus centrifugal pump. Ann Thorac Surg. 1999;68(2):650-654. Medline. doi:10.1016/S00034975(99)00580-9
3. Murphy GJ, Angelini GD. Side effects of cardiopulmonary
bypass: what is the reality? J Card Surg. 2004;19(6):481488. Medline. doi:10.1111/j.0886-0440.2004.04101.x
4. Goldstein DJ, Oz MC. Mechanical support for postcardiotomy cardiogenic shock. Semin Thorac Cardiovasc Surg.
2000;12(3):220-228. Medline.
5. Klotz S, Rukosujew A, Welp H, Schmid C, Tjan TD, Scheld
HH. Primary extracorporeal membrane oxygenation versus primary ventricular assist device implantation in low
cardiac output syndrome following cardiac operation. Artif
Organs. 2007;31(5):390-394. Medline. doi:10.1111/j.15251594.2007.00397.x
6. Ko WJ, Lin CY, Chen RJ, Wang SS, Lin FY, Chen YS. Extracorporeal membrane oxygenation support for adult postcardiotomy cardiogenic shock. Ann Thorac Surg. 2002;73(2):538545. Medline. doi:10.1016/S0003-4975(01)03330-6
372
Conflict of interest statement: The authors have no conflict of interest to disclose.
Address for correspondence:
PD Dr. A. Beiras-Fernandez
Department of Cardiac Surgery
Grosshadern-Hospital
Ludwig-Maximilians-University Munich
Marchioninistrasse 15
81377 Munich, Germany
e-mail:[email protected]
© 2011 Wichtig Editore - ISSN 0391-3988
Beiras-Fernandez et al
14. 15. 16. 17. 18.
membrane oxygenation for refractory cardiogenic shock.
Crit Care Med. 2008;36(5):1404-1411. Medline. doi:10.1097/
CCM.0b013e31816f7cf7
Ghez O, Feier H, Ughetto F, Fraisse A, Kreitmann B, Metras
D. Postoperative extracorporeal life support in pediatric cardiac surgery: recent results. ASAIO J. 2005;51(5):513-516.
Medline. doi:10.1097/01.mat.0000178039.53714.57
Shah SA, Shankar V, Churchwell KB, et al. Clinical outcomes
of 84 children with congenital heart disease managed with
extracorporeal membrane oxygenation after cardiac surgery.
ASAIO J. 2005;51(5):504-507. Medline. doi:10.1097/01.
mat.0000171595.67127.74
Chaturvedi RR, Macrae D, Brown KL, et al. Cardiac ECMO
for biventricular hearts after paediatric open heart surgery. Heart. 2004;90(5):545-551. Medline. doi:10.1136/
hrt.2002.003509
Sachweh JS, Tiete AR, Fuchs A, et al. Efficacy of extracorporeal membrane oxygenation in a congenital heart surgery
program. Clin Res Cardiol. 2007;96(4):204-210. Medline.
doi:10.1007/s00392-007-0484-1
Balasubramanian SK, Tiruvoipati R, Amin M, et al. Factors
influencing the outcome of paediatric cardiac surgical patients during extracorporeal circulatory support. J Cardio-
thorac Surg. 2007;11;2:4.
19. Chan T, Thiagarajan RR, Frank D, Bratton SL. Survival after extracorporeal cardiopulmonary resusciation in infants and children with heart disease. J Thorac Cardiovasc Surg. 2008;136:984-992. Medline. doi:10.1016/j.
jtcvs.2008.03.007
20. Kolovos NS, Bratton SL, Moler FW, et al. Outcome of pediatric patients treated with extracorporeal life support after
cardiac surgery. Ann Thorac Surg. 2003;76(5):1435-1442.
doi:10.1016/S0003-4975(03)00898-1
21. Kasirajan V, Smedira NG, McCarthy JF, Casselman F, Boparai
N, McCarthy PM. Risk factors for intracranial hemorrhage in
adults on extracorporeal membrane oxygenation. Eur J Cardiothorac Surg. 1999;15(4):508-514. Medline. doi:10.1016/
S1010-7940(99)00061-5
22. Jarjour IT, Ahdab-Barmada M. Cerebrovascular lesions in
infants and children dying after extracorporeal membrane
oxygenation. Pediatr Neurol. 1994;10(1):13-19. Medline.
doi:10.1016/0887-8994(94)90061-2
23. Hoshi H, Shinshi T, Takatani S. Third-generation blood
pumps with mechanical noncontact magnetic bearings. Artif
Organs. 2006;30(5):324-338. Medline. doi:10.1111/j.15251594.2006.00222.x
© 2011 Wichtig Editore - ISSN 0391-3988
373