Ann Thorac Surg. 2006 Nov;82(5):1796-801. 

Abdominal complications after heart surgery.

Khan JH, Lambert AM, Habib JH, Broce M, Emmett MS, Davis EA.

Charleston Area Medical Center, Charleston, West Virginia, USA.
jamal.khan@camc.org

BACKGROUND: Up to 3% of patients undergoing heart surgery suffer from an
intraabdominal complication (IAC). These complications carry a high mortality
besides adding to the morbidity and cost. This review was undertaken to see if a
subset of patients with increased risk of IAC could be identified. METHODS:
Medical records of 7,731 consecutive patients undergoing heart surgery in a
single center were screened for identification of postoperative IAC. One hundred
and twenty (120) cases were found. One hundred and six (106) cases were compared
with the same number of matched controls. RESULTS: Significant predictors of the
development of IAC were increased cardiopulmonary bypass times (> 99 minutes),
peripheral vascular disease, chronic steroid use, and low left ventricular
ejection fraction. Patients on postoperative antiplatelet therapy or warfarin
had a lower risk of IAC. Significant predictors of mortality in IAC were
increased cardiopulmonary bypass times (> or = 120 minutes.), use of inotropes,
cerebral vascular disease, and incremental age. CONCLUSIONS: A subset of
patients can be identified who are at higher risk for IAC and an associated
adverse outcome. Patients who have prolonged cardiopulmonary bypass, have a low
left ventricular ejection fraction, are on steroids, and suffer from other
vascular disease should be observed carefully for development of IAC.
Postoperative anticlotting strategies may be helpful. Early diagnosis and
intervention are essential for improving outcomes in cases of IAC.

Crit Care. 2006 Nov 29;10(6):R167 [Epub ahead of print] 

Hyperlactatemia during cardiopulmonary bypass: determinants and impact on
postoperative outcome.

Ranucci M, De Toffol B, Isgro G, Romitti F, Conti D, Vicentini M.

BACKGROUND: hyperlactatemia during cardiopulmonary bypass is
relatively frequent and is associated with an increased postoperative morbidity.
The aim of this study is to determine which perfusion-related factors may be
responsible for hyperlactatemia, with specific respect to hemodilution and
oxygen delivery, and to verify the clinical impact of hyperlactatemia during
cardiopulmonary bypass in terms of postoperative morbidity and mortality rate.
Methods: 500 consecutive patients undergoing cardiac surgery with
cardiopulmonary bypass have been admitted to this prospective observational
study. During cardiopulmonary bypass, serial arterial blood gas analyses with
blood lactate and glucose determinations have been obtained. Hyperlactatemia was
defined as a peak arterial blood lactate concentration exceeding 3 mMol/L. Pre
and intraoperative factors have been tested for independent association with the
peak arterial lactate concentration and hyperlactatemia. The postoperative
outcome of patients with or without hyperlactatemia was compared. Results:
factors independently associated with hyperlactatemia were the preoperative
serum creatinine value, the presence of active endocarditis, the cardiopulmonary
bypass duration, the lowest oxygen delivery during cardiopulmonary bypass and
the peak blood glucose level. Once corrected for other explanatory variables,
hyperlactatemia during cardiopulmonary bypass remained significantly associated
with an increased morbidity, mainly related to a postoperative low cardiac
output syndrome, but not to mortality. Conclusions: hyperlactatemia during
cardiopulmonary bypass appears to be mainly related to a condition of
insufficient oxygen delivery (type A hyperlactatemia). During cardiopulmonary
bypass it seems therefore mandatory a careful coupling of pump flow and arterial
oxygen content, in order to guarantee a sufficient oxygen supply to the
peripheral tissues.

Cytometry B Clin Cytom. 2006 Nov 28; [Epub ahead of print] 

Granulocyte- and monocyte-platelet adhesion index in coronary and peripheral
blood after extracorporeal circulation and reperfusion.

Sbrana S, Buffa M, Bevilacqua S, Spiller D, Parri MS, Gianetti J, De Filippis R,
Clerico A.

Laboratory of Hematology and Flow Cytometry, CNR Institute of Clinical
Physiology, Massa, Italy.

BACKGROUND:: Neutrophil-granulocyte and mononuclear-cell functional changes
occur during cardiopulmonary bypass and cardiovascular surgery. In particular,
leukocyte-platelet interaction, leading to generation of heterotypic
coaggregates, represents an amplification mechanism of the local inflammatory
response and tissue damage. METHODS:: Samples of 20 patients were drawn from
venous coronary sinus before cardioplegic arrest and immediately after
reperfusion, as well as from peripheral blood at 5 and 24 h postoperatively. The
granulocyte and monocyte surface expression of CD162, CD15s, CD18, and CD11b
were quantified by flow cytometry at the different times. Parallel variations of
circulating leukocyte-platelet conjugates (percentages) and a derived (cell
number-normalized) leukocyte-platelet adhesion index were measured using a
combination of antibodies against CD45, CD14, and CD41a. The evaluation of
platelet functional state was carried out using antibodies against CD62P
(P-selectin) and PAC-1. RESULTS:: Monocyte and granulocyte cell number increased
markedly in coronary blood at reperfusion and in peripheral blood
postoperatively when compared with measurements done before cardioplegia. A very
different course characterized the changes of the leukocyte-platelet adhesion
index with respect to the variations of circulating leukocyte-platelet
coaggregates (percentages). Leukocyte molecules expression showed no significant
variations for CD15s on both the leukocyte subsets, while a significant
up-modulation for CD162 was observed on monocytes at 24 h after extracorporeal
circulation (P = 0.0002), and for CD11b on granulocytes at 5 h postoperatively
(P = 0.033). A loss of CD162 expression was observed in coronary blood at
reperfusion (P = 0.0038) on granulocytes, associated to a down-modulation of
CD18 (P = 0.0033) and CD11b (P = 0.0184) in peripheral blood at 24 h
postoperatively. No significant up-regulation of platelet activatory molecules
expression was found at coronary reperfusion, as well as postoperatively in the
peripheral blood, when compared with the before-cardioplegia derived data.
CONCLUSIONS:: The over time variations of a normalized leukocyte-platelet
adhesion index seem to reflect the cumulative leukocyte-platelet functional
interaction more accurately than the parallel measurements of cellular
conjugates. The absence of platelet activation suggests that the leukocyte
membrane modifications play a main role in controlling the formation and
stability of heterotypic leukocyte-platelet coaggregates after cardiac surgery
with extracorporeal circulation. (c) 2006 International Society for Analytical
Cytology.

Crit Care Med. 2006 Nov 22; [Epub ahead of print] 

Mechanisms of a reduced cardiac output and the effects of milrinone and
levosimendan in a model of infant cardiopulmonary bypass.

Stocker CF, Shekerdemian LS, Norgaard MA, Brizard CP, Mynard JP, Horton SB,
Penny DJ.

From the Departments of Intensive Care (CFS, LSS), Cardiac Surgery (MAN, CPB,
SBH), and Cardiology (DJP), The Royal Children's Hospital, Melbourne, Australia;
and the Australia and New Zealand Children's Heart Research Centre, Murdoch
Children's Research Institute, Melbourne, Australia (CFS, LSS, CPB, JPM, DJP).

OBJECTIVES:: A low cardiac output state is an important cause of morbidity after
pediatric cardiopulmonary bypass. The objectives of our study were to define the
early precipitants of the reduced cardiac output and to investigate the effects
on these of milrinone and levosimendan in a model of pediatric cardiopulmonary
bypass. DESIGN:: Experimental study. SETTING:: Research laboratory at a
university-affiliated, tertiary pediatric center. SUBJECTS:: Eighteen piglets.
INTERVENTIONS:: Piglets, instrumented with systemic, pulmonary arterial, and
coronary sinus catheters, pulmonary and circumflex arterial flow probes, and a
left ventricular conductance-micromanometer-tipped catheter, underwent
cardiopulmonary bypass with aortic cross-clamp and cardioplegic arrest. At 120
mins, they were assigned to control, milrinone, or levosimendan groups and
studied for a further 120 mins. MEASUREMENTS AND MAIN RESULTS:: In controls,
between 120 and 240 mins, cardiac output decreased by 15%. Systemic vascular
resistance was unchanged, but pulmonary vascular resistance increased by 19%.
Systemic arterial elastance increased by 17%, indicating increased afterload.
End-systolic elastance was unchanged, and coronary sinus oxygen tension
decreased by 4.0 +/- 1.7 mm Hg. In animals receiving milrinone cardiac output
was preserved, and in animals receiving levosimendan cardiac output increased by
14%. Both drugs prevented an increase in arterial elastance and pulmonary
vascular resistance after cardiopulmonary bypass. Systemic vascular resistance
decreased by 31% after levosimendan, and end-systolic elastance increased by
48%, indicating improved contractility. Both agents prevented a decrease in
coronary sinus oxygen tension. CONCLUSIONS:: Increased afterload, which is not
matched by an equivalent elevation in contractility, contributes to the reduced
cardiac output early after pediatric cardiopulmonary bypass in this model. This
increase is prevented by milrinone and levosimendan. Both agents exert
additional beneficial effects on pulmonary vascular resistance and myocardial
oxygen balance, although levosimendan has greater inotropic properties.

J Clin Monit Comput. 2006 Nov 11; [Epub ahead of print] 

Variation in Blood Pressure as a Guide to Volume Loading in Children Following
Cardiopulmonary Bypass.

Tran H, Froese N, Dumont G, Lim J, Ansermino JM.

Departments of Electrical & Computer Engineering, The University of British
Columbia, Vancouver, V6H 3V4, Canada.

OBJECTIVE: Intravascular volume loading is used to optimize cardiac output in
children following weaning from cardiopulmonary bypass. Central venous pressure
(CVP) is frequently used to titrate fluid administration but it is often
misleading in predicting fluid responsiveness. Variation in the arterial
pressure waveform is exaggerated in patients with deficient intravascular volume
and has been shown to be a good predictor of fluid responsiveness in adults
following cardiac surgery. The aim of this study was to compare the measures of
variation in blood pressure as a guide to volume loading in children following
cardiopulmonary bypass. METHODS: After ethical approval, we collected continuous
real-time measurements from 25 children during volume loading after
cardiopulmonary bypass. Subjects with moderate or severe tricuspid incompetence
or who did not require volume loading during weaning from cardiopulmonary bypass
were excluded from the study. Unstable readings were excluded from analysis.
Systolic Pressure Variation (SPV), Pulse Pressure Variation (PPV) and Systolic
Volume Variation (SVV) were retrospectively calculated before and after each
bolus of fluid. Fluid responsiveness was classified as a change in blood
pressure of >/=80 mmHg/L/m(2). RESULTS: Forty-four boluses were analyzed from
the 25 children. Respiratory variables were similar. CVP was a poor predictor of
fluid responsiveness and a negative relationship between change in blood
pressure and DeltaDown was observed. Performance in predicting fluid
responsiveness as measured by the areas under the ROC curves were CVP (0.58),
PPV (0.67), SPV (0.74) and SVV (0.74). CONCLUSIONS: Variation in blood pressure
was a better guide to volume loading in children than CVP. Deltadown was not
useful in predicting fluid responsiveness in children with open chests following
bypass surgery. SPV and SVV require further testing in prospective clinical
trials.

Blood Coagul Fibrinolysis. 2006 Nov;17(8):639-45. 

Tranexamic acid does not correct the haemostatic impairment caused by
hydroxyethyl starch (200 kDa/0.5) after cardiac surgery.

Kuitunen AH, Suojaranta-Ylinen RT, Kukkonen SI, Niemi TT.

Department of Anaesthesiology and Intensive Care Medicine, Helsinki University
Hospital, Meilahti Hospital, Helsinki, Finland.

We investigated the effect of intravenous tranexamic acid on hydroxyethyl starch
(HES)-induced clot strength impairment after cardiac surgery. Patients were
randomized to receive either 1 g tranexamic acid or the same volume of 0.9%
saline after administration of 15 ml/kg of 6% HES (molecular weight, 200 kDa;
degree of substitution, 0.5) in the immediate postoperative period. Modified
thromboelastometry (ROTEM) using different activators [intrinsic ROTEM (InTEM),
extrinsic ROTEM (ExTEM), fibrinogen ROTEM (FibTEM)] was carried out to evaluate
clot formation and lysis. The clot formation time was prolonged, and the maximum
clot firmness (MCF) and shear elastic modulus [G = 5000 x MCF / (100-MCF),
dynes/cm] decreased (all activators of ROTEM) after completion of HES (P <
0.001, two-factor analysis of variance). These abnormalities in blood
coagulation persisted despite tranexamic acid. Maximal lysis (FibTEM),
indicative of fibrinolytic activity, was increased after HES but no effect of
tranexamic acid was observed. The cumulative chest tube drainage until the first
postoperative morning was not different between the groups (1008 +/- 251 and
1081 +/- 654 ml, P = 0.698, respectively). We conclude that after
cardiopulmonary bypass, HES-induced impairment in clot formation and strength,
or increased fibrinolytic capacity, is not reversed by the administration of
tranexamic acid.

Diabetes Metab Res Rev. 2006 Nov 6; [Epub ahead of print] 

Insulin-based regimens decrease mortality rates in critically ill patients: a
systematic review.

Langley J, Adams G.

Intensive Care, Lincoln County Hospital, Greetwell Road, Lincoln, Lincolnshire,
LN2 5QY, UK.

OBJECTIVES: To determine whether treatment with glucose-insulin-potassium (GIK),
insulin and glucose, or insulin by itself is beneficial in limiting organ damage
after acute myocardial infarction (AMI) and reducing mortality and morbidity
among critically ill hyperglycaemic patients. METHODS: Systematic review of
randomized controlled trials. MAIN OUTCOME MEASURE: To assess whether tight
glycaemic control reduces morbidity and mortality. STUDIES REVIEWED: Randomized
controlled trials of insulin-based regimens in the treatment of critically ill
patients. RESULTS: Nine hundred and twenty-four potentially relevant studies
were identified and screened for retrieval. Of these, 16 randomized controlled
trials met the inclusion criteria (Table 1). Ten studies examined the effects of
GIK, and six of these studies reported a mortality reduction with GIK treatment
in addition to enhanced myocardial performance. Five studies examined the
administration of insulin. Among these studies, tight glycaemic control of blood
glucose in one study was shown to reduce morbidity and mortality of patients in
intensive care. Only one study examined insulin/glucose therapy, and it showed a
post-myocardial infarction mortality reduction of one year. 1Description of
Studies in Order of Treatment(Glucose-Insulin-Potassium-GIK)Study
No.SourceYearStudy titleStudy design/descriptionStudy findings-whether tight
glycaemic control improves morbidity and mortality2Lazar et al.1997GIK solutions
enhance recovery after urgent coronary artery bypass graftingStudy undertaken to
determine whether GIK solutions would benefit patients undergoing coronary
artery bypass grafting.Although no mortality was evident in either group. GIK
therapy enhances myocardial performance and results in faster recovery from
urgent coronary artery bypass grafting.The study group consisted of 30 patients
with unstableangina who required coronary artery bypass surgery: 15 patients
randomized to treatment with GIK solution administered intravenously after
induction of anaesthesia and continued for 12 h after aortic unclamping, the
remaining 15 patients received intravenous 5% dextrose in water.3Diaz et
al.1998Metabolic modulation of AMI: The ECLA GIK pilot trialStudy conducted to
evaluate the impact of a GIK infusion administered during the first few hours of
AMI.A trend toward a non-significant reduction in major and minor in-hospital
events was observed in patients allocated to GIK. However, in the patients
treated with reperfusion strategies, a statistically significant reduction in
mortality and a consistent trend toward fewer in-hospital events in the GIK
group was observed.A total of 407 patients with suspected AMI were studied. In a
ratio of 2 : 1 patients, 268 were randomized to receive GIK (high or low dose)
and 139 to receive control.4Scott et al.1999GIK infusions in the treatment of
acute stroke patients with mild to moderate hyperglycaemia. The glucose-insulin
in stroke trial (GIST)Study designed to determine whether glucose/insulin
induced and maintained euglycaemia in acute stroke patients with mild to
moderate hyperglycaemia can improve outcome after stroke. Fiftythree acute
stroke patients with mild to moderate hyperglycaemia (7-17 mmol/L) were studied:
25 randomized to treatment with a GIK infusion (insulin concentration in the GIK
was altered according to BM glucose values) and 28 to the control, which were
administered as sodium chloride infusion.Results confirm that GKI infusion in
mild to moderate hyperglycaemia following acute stroke is a safe, practical, and
pragmatic intervention that effectively lowers the plasma glucose levels to
within normal range; however, the beneficial effects of this treatment remain to
be elucidated.5Ceremuzynski et al.1999Low-dose GIK is ineffective in AMI:
results of a randomized multi-centre Pol-GIK trialStudy designed to assess the
clinical efficacy of GIK infusion in AMI.Low-dose GIK treatment does not improve
the survival and clinical course in AMI.The study consisted of 954 patients: 494
randomized to treatment with low-dose GIK infusion and 460 to the control group,
which was administered sodium chloride by IV infusion.Total mortality at 35 days
was significantly higher in the GIK infusion group than in the control
group.6Besogul et al.1999Chemical, biochemical and histochemical assessment of
pre-treatment with GIK for patients undergoing mitral valve replacement in the
third and forth functional groups of the New York Heart Association.A study
designed to investigate the potentially beneficial effects of pre-operative
treatment with GIK for patients undergoing mitral valve replacement.No
significant reduction in mortality was evident throughout the period of the
trial; however, the patients receiving GIK required less inotropic support, had
fewer ventricular arrhythmias, and exhibited improved haemodynamic indices:
cardiac output increased & systemic vascular resistance decreased.A total of 30
patients were studied: 15 randomly assigned to treatment with GIK infusion and
15 to the control group, which was administered an equivalent volume of sodium
chloride.7Lazar et al.2000GIK solutions improve outcomes in diabetic patients
who have coronary artery operations.Study undertaken to determine whether GIK
would improve myocardial performance and limit morbidity after coronary artery
bypass grafting in diabetic patients.Although no mortality was evident in either
group. GIK therapy enhances myocardial performance and results in faster
recovery from urgent coronary artery bypass grafting.A total of 40 patients were
studied: 20 randomized to receive a GIK infusion and 20 to the control group,
which received 5% dextrose in water.9Ulgen et al.2001The effect of GIK solution
on ventricular late potentials and heart rate variability in AMI.Study designed
to investigate the effects of GIK solution on ventricular late potentials (VLP)
and high rate variability (HRV) during the early period of AMI.Although
treatment with GIK solution did not find a statistically significant reduction
in mortality, the results suggest that GIK therapy in the early periods of AMI
shows beneficial effects: decreased post-myocardial infarction angina and
ischaemia.(High rate variability and presence of VLP are known to correlate with
an increased risk of ventricular tachycardia and sudden death in AMI.)A total of
72 patients were studied: 34 randomized to treatment with GIK and 38 to the
placebo.10Szabo et al.2001Effects of high-dose GIK on myocardial metabolism
after coronary surgery in patients with type 2 diabetes.Study designed to
investigate the effects of high-dose GIK on myocardial substrate utilization
after coronary surgery in patients with type 2 diabetes.Although no mortality
was evident in either group, it can be concluded that high-dose GIK
significantly enhances myocardial performance.A total of 20 patients were
randomly allocated: 10 received high-dose GIK infusion post-operatively and the
remaining 10 in the control group received standard post-operative care,
including insulin infusion if required, to maintain blood glucose below 10
mmol/L.11Smith et al.2002Coronary revascularisation: a procedure in transition
from on-pump to off-pump? The role of GIK revisited in a randomized,
placebo-controlled studyA study designed to investigate an optimized GIK
solution regimen as an alternative myocardial protective strategy in off-pump
coronary artery bypass graft surgery and as a supplement to conventional
coronary artery bypass surgery using cardiopulmonary bypass (CPB). The study
consisted of 44 patients scheduled for elective multi vessel surgery using
either conventional CPB (n = 22) or off-pump coronary artery bypass techniques
(n = 22). Pre-ischaemic, ischaemic, and post-ischaemic administration of GIK
solution was carried out, (optimally dosed to ensure non-esterfied fatty acid
suppression (NEFA), and supplemented with magnesium (a glycolytic cofactor).GIK
solution did not achieve any clinical benefit. However, compared with CPB,
off-pump coronary artery bypass surgery significantly reduced ischaemic injury
and post-operative infections.13Lell et al.2002GIK infusion for myocardial
protection during off-pump coronary artery surgery.Study undertaken to evaluate
the clinical effectiveness of GIK infusion in preventing myocardial damage and
maintaining cardiac performance in patients undergoing off-pump myocardial
revascularization.A GIK infusion used as an adjunct to reperfusion therapy for
AMI causes insulin-resistant hyperglycaemia in elective off-pump coronary artery
bypass patients, with no demonstrable benefit.A total of 46 patients undergoing
off-pump coronary artery bypass were studied: 21 were randomly assigned to
treatment with GIK infusion and 20 to the control group, which was administered
sodium chloride (five patients were excluded due to cardiovascular
instability).Insulin-only Infusion16Ingels et al.2006Strict blood glucose
control with insulin during intensive care after cardiac surgery: impact on 4
years survival, dependency on medical care, and quality of lifeSub-analysis and
follow-up study of a large, randomized controlled trial on the effects of
intensive insulin therapy during critical illnessShort-term survival benefit was
obtained after 4 years, without inducing increased medical care requirements,
with insulin-titrated glycaemic control maintained during intensive care after
cardiac surgery.15Van den Berghe et al.2006Intensive insulin therapy in the
medical ICUA prospective, randomized, controlled study of adult patients
admitted to our medical ICU. On admission, patients were randomly assigned to
strict normalization of blood glucose levels (80-110 mg/dL, 4.4-6.1 mmol/L) with
the use of insulin infusion or to conventional therapy (insulin administered
when the blood glucose level exceeded 215 mg per/dL (12 mmol/L), with the
infusion tapered when the level fell below 180 mg/dL (10 mmol/L)). There was a
history of diabetes in 16.9% of the patients.Intensive insulin therapy
significantly reduced morbidity, but not mortality, among all patients in the
medical ICU. Although the risk of subsequent death and disease was reduced in
patients treated for three or more days, these patients could not be identified
before therapy.8Van den Berghe et al.2001Intensive insulin therapy in critically
ill patientsStudy designed to assess whether normalization of blood glucose
levels with intensive insulin therapy reduces mortality and morbidity among
critically ill patients.Intensive insulin therapy to maintain blood glucose at
or below 6.1 mmol/L reduces morbidity and mortality among critically ill
patients in the surgical ICU.A total of 1548 were studied: 783 randomly assigned
to the intensive treatment group with the aim of maintaining normoglycaemia
(4.4-6.1 mmol/L) and 765 to the conventional group in which an insulin infusion
was titrated to maintain blood glucose levels between 10 & 11.1 mmol/L.12Groban
et al.2002Intra-operative insulin therapy does not reduce the need for inotropic
or anti-arrhythmic therapy after cardiopulmonary bypassStudy designed to
determine whether attempted glucose control through intra-operative insulin
therapy reduces the need for inotropic or anti-arrhythmic therapy after
cardiopulmonary bypass.Intra-operative insulin therapy did not reduce mortality
or the use of inotropic or anti-arrhythmic support after cardiac surgery with
CPB.A total of 381 patients were studied: 188 randomized to treatment with
insulin infusion in an attempt to maintain blood glucose within set parameters
and 193 to the control group, which was administered sodium chloride.14Rao et
al.2002The insulin cardioplegia trial: myocardial protection for urgent coronary
artery bypass graftingStudy undertaken to evaluate the clinical impact of
insulin-enhanced cardioplegia on patients at high risk and undergoing coronary
artery bypass surgery for unstable angina.Despite encouraging results from
smaller studies, the trial failed to demonstrate any clinical benefit of
insulin-enhanced cardioplegia solution for patients undergoing high-risk
isolated coronary artery bypass grafting.A total of 1127 patients were studied:
557 were randomly assigned at operation to receive cardioplegic solution
supplemented with insulin and 570 were assigned to a placebo.Insulin-Glucose
Method of Administration1Malmberg et al.1995Randomized trial of insulin-glucose
infusion followed by subcutaneous insulin treatment in diabetic patients with
AMI : effects on mortality at one year.Study investigating how insulin-glucose
infusion followed by multi-dose insulin treatment in diabetic patients with AMI
affected mortality during the subsequent 12 months of follow-up.Insulin-glucose
infusion followed by multi-dose insulin regime statistically improved long-term
prognosis in diabetic patients with AMI.A total of 620 patients were studied:
306 were randomized to treatment with insulin-glucose infusion followed by
multi-dose subcutaneous insulin for more that 3 months, and 314 to conventional
therapy (insulin administered only if deemed clinically necessary). CONCLUSIONS:
There is increasing evidence that maintaining normoglycaemia and treatment with
insulin-based regimens is beneficial in limiting organ damage and significantly
reduces both morbidity and mortality in critically ill patients who require
intensive care therapy.

J Clin Monit Comput. 2006 Nov 4; [Epub ahead of print] 

Conductivity-Based Hematocrit Measurement During Cardiopulmonary Bypass.

Steinfelder-Visscher J, Weerwind PW, Teerenstra S, Pop GA, Brouwer RM.

Department of Extra-Corporeal Circulation (677), Radboud University Nijmegen
Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands,
p.weerwind@thorax.umcn.nl.

OBJECTIVE: In a recent clinical study on the reliability of a point-of-care
(POC) analyzer, we described a downward bias in hematocrit measurement during
cardiopulmonary bypass leading potentially to overtreatment with packed red
cells. We hypothesized that the detected deviation is caused by variations in
electrolyte concentration rather than by colloids used. METHODS: Blood was
sampled from patients before cardiac surgery to obtain undiluted anticoagulated
whole blood samples (n = 53). From each sample, four dilution series covering a
hematocrit range of 15-30% were made using NaCl (0.9%), modified gelatine (4%),
hydroxyethylstarch (6%), or a potassium-based (16 mEq/l) solution, respectively.
In each dilution series, hematocrit was measured by POC and via the "golden
standard" microcentrifugal method to determine whether the deviation of the
POC-analyzer to the microcentrifuge was dependent on the type and dilution level
of the solution used. RESULTS: In contrast to the colloid-based dilution series,
the crystalloids revealed a significant downward bias of the POC-analyzer with
respect to the microcentrifuge (p < 0.05). Due to the correction algorithm for
sodium in the POC-analyzer, this deviation was nearly constant for NaCl (mean of
difference: -1.8 +/- 0.1%), but increased significantly in case of the
potassium-based solution (up to -8.2 +/- 0.4% after 1.5-times dilution). The
starch- and gelatine-based solutions led to a significant upward bias (p < 0.05)
that increased with progressing dilution (up to 1.2 +/- 0.1% for
hydroxyethylstarch and up to 1.3 +/- 0.1% for modified gelatine after 1.5-times
dilution). CONCLUSIONS: Conductivity-based POC hematocrit measurement suffers
from biases due to changes of the plasma constituents. The downward bias in
hematocrit as often seen during cardiopulmonary bypass is driven by changes of
different electrolyte concentration rather than by colloids used per se.

J Am Coll Cardiol. 2006 Nov 7;48(9):1859-64. Epub 2006 Oct 17. 

Adverse effects of dopamine on systemic hemodynamic status and oxygen transport
in neonates after the Norwood procedure.

Li J, Zhang G, Holtby H, Humpl T, Caldarone CA, Van Arsdell GS, Redington AN.

Cardiac Program, the Hospital for Sick Children, Toronto, Ontario, Canada.

OBJECTIVES: The purpose of this study was to evaluate the effects of dopamine on
hemodynamic status and oxygen transport in neonates after the Norwood procedure.
BACKGROUND: Dopamine is widely used to augment cardiac performance and increase
oxygen delivery (DO2) in patients after cardiopulmonary bypass (CPB). This might
be at the expense of increased myocardial and systemic oxygen consumption (VO2),
thus offsetting the improved DO2. This balance is particularly fragile in
critically ill neonates. METHODS: Systemic oxygen consumption was continuously
measured with respiratory mass spectrometry in 13 sedated, paralyzed, and
mechanically ventilated neonates for 72 h after the Norwood procedure. Arterial,
superior vena caval, and pulmonary venous blood gases were measured to calculate
pulmonary blood flow (Q(p)) and systemic blood flow (Q(s)), DO2, and oxygen
extraction ratio (ERO2). Rate-pressure product was calculated. Dopamine at a
dose of 5 microg/kg/min was routinely administered at cessation of CPB and
terminated within the first 48 h. Hemodynamic and oxygen transport measures were
obtained before and at 100 min after the termination of dopamine. RESULTS:
Terminating dopamine was not associated with significant changes in arterial
pressure, Q(p), Q(s), or DO2 but was associated with a significant decrease in
heart rate (p = 0.003), rate-pressure product (p = 0.03), and VO2 (-20 +/- 11%,
p < 0.0001), resulting in a significant decrease in ERO2 (p = 0.01).
CONCLUSIONS: Dopamine induces a significant increase in VO2 in neonates after
the Norwood procedure, and termination is associated with an improved balance of
VO2-DO2. These data further emphasize the importance of understanding changes in
VO2 as well as DO2 in infants after cardiac surgery.

J Card Surg. 2006 Nov-Dec;21(6):572-7. 

Biocompatibility of Heparin-Coated Cardiopulmonary Bypass Circuits in Coronary
Patients With Left Ventricular Dysfunction Is Superior to PMEA-Coated Circuits.

Kutay V, Noyan T, Ozcan S, Melek Y, Ekim H, Yakut C.

Cardiovascular Surgery Clinic, Yuzuncu Yil University, Van, Turkey.

Background: Several coating techniques for extracorporeal circulation have been
developed to diminish the systemic inflammatory response during cardiopulmonary
bypass (CPB). The aim of this study was to evaluate the clinical effectiveness
and biocompatibility of heparin-coated and poly-2-methoxyethylacrylate
(PMEA)-coated CPB circuits on coronary patients with left ventricular systolic
dysfunction. Methods: Thirty-six patients who underwent elective coronary artery
bypass grafting were divided into two equal groups: group H (n = 18),
heparin-coated; group P (n = 18), PMEA coated. Clinical outcomes, hematologic
variables, cardiac enzymes, malondialdehyde (MDA), and acute phase inflammatory
response (including myeloperoxidase (MPO), catalase, hsCRP, and IL-8) were
analyzed perioperatively. Results: Demographic, CPB, and clinical outcome data
were similar for both groups. Plasma fibrinogen, total protein, albumin, and
platelet count decreased, neutrophil count, MDA, IL-8, MPO, and catalase levels
increased during CPB. During CPB, MPO and catalase values were significantly
higher in group P (p = 0.02 and p = 0.01) and postoperative MDA concentration
was lower in group H (p = 0.03). Platelet counts were better preserved in group
H during and after CPB but neutrophil count and IL-8 level did not differ
between the groups. Postoperative total protein, albumin, and fibrinogen levels
were higher in group H (p < 0.05). The postoperative first day levels of
troponin-I, CK-MB, and CRP increased in both groups without any significant
differences between the groups. Conclusions: Heparin-coated circuit provided
better suppression of perioperative inflammatory markers and exhibited more
favorable effects on hematologic variables than PMEA-coated circuit.