J Cardiothorac Vasc Anesth. 2006 Feb;20(1):43-7. Epub 2005 Dec 1. 

Serum lactate level has prognostic significance after pediatric cardiac surgery.

Basaran M, Sever K, Kafali E, Ugurlucan M, Sayin OA, Tansel T, Alpagut U,
Dayioglu E, Onursal E.

Department of Cardiovascular Surgery, Istanbul University, Istanbul, Turkey.

Objective: The determination of postoperative course after cardiac surgery has
always been a challenging issue. It is more sophisticated in the pediatric age
group. The aim of this investigation was to identify whether increased
concentrations of lactate in arterial blood has a predictive value for
postoperative morbidity and mortality after heart surgery. Methods: From May
2002 to June 2003, 60 infants operated on at the authors' institution were
included in this prospective study. The patients were divided into 2 groups
according to their respective postoperative serum lactate values. After the
stabilization period in the intensive care unit (first 3 hours postoperatively),
samples for serum lactate were obtained from arterial blood at 3 (t(1)), 6
(t(2)), and 12 hours (t(3)) postoperatively. The patients were subdivided into 2
groups according to their respective mean serum lactate values. A value of 4.8
mmol/L (3 times the normal upper limit) was choosen as a threshold for serum
lactate. The patients with a mean value of greater than 4.8 mmol/L (group 1)
were compared with the remaining group of patients (group 2). The relationship
between serum mean lactate level and intraoperative and postoperative clinical
variables was evaluated. Results: Among the patients in this study, 26 (43.3%)
had a serum mean lactate level more than 4.8 mmol/L and 34 (56.7%) had a level
of 4.8 mmol/L or less. Age, aortic cross-clamping time, cardiopulmonary bypass
time, and the lowest hematocrit during cardiopulmonary bypass were significant
variables that influenced the postoperative serum mean lactate level. Six
patients died in the postoperative period and 54 infants survived. The hospital
mortality was significantly higher in group 1 than in group 2 (19.0% v 2.9%; p =
0.037, kappa = 0.179). Multivariate analysis revealed that serum mean lactate
level correlated significantly with inotrope score, intubation time, and
intensive care unit stay. Conclusions: Blood lactate concentration of 4.8 mmol/L
or higher during the early postoperative hours identifies a group of patients
with increased risk of postoperative morbidity and mortality.

Cardiol Young. 2006 Feb;16(1):48-53. 

Quantitative analysis of procalcitonin after pediatric cardiothoracic surgery.

Michalik DE, Duncan BW, Mee RB, Worley S, Goldfarb J, Danziger-Isakov LA, Davis
SJ, Harrison AM, Appachi E, Sabella C.

Division of Pediatrics, The Children's Hospital, The Cleveland Clinic,
Cleveland, Ohio, United States of America.

Procalcitonin appears to be an early and sensitive marker of bacterial infection
in a variety of clinical settings. The use of levels of procalcitonin to predict
infection in children undergoing cardiac surgery, however, may be complicated by
the systemic inflammatory response that normally accompanies cardiopulmonary
bypass. The aim of our study was to estimate peri-operative concentrations of
procalcitonin in non-infected children undergoing cardiac surgery. Samples of
serum for assay of procalcitonin were obtained in 53 patients at baseline, 24,
48, and 72 hours following cardiac surgery. Concentrations were assessed using
an immunoluminetric technique. Median concentrations were lowest at baseline at
less than 0.5 nanograms per millilitre, increased at 24 hours to 1.8 nanograms
per millilitre, maximized at 48 hours at 2.1 nanograms per millilitre, and
decreased at 72 hours to 1.3 nanograms per millilitre, but did not return to
baseline levels. Ratios of concentrations between 24, 48 and 72 hours after
surgery as compared to baseline were 6.15, with 95 percent confidence intervals
between 4.60 and 8.23, 6.49, with 95 percent confidence intervals from 4.55 to
9.27, and 4.26, with 95 percent confidence intervals between 2.78 and 6.51,
respectively, with a p value less than 0.001. In 8 patients, who had no evidence
of infection, concentrations during the period from 24 to 72 hours were well
above the median for the group. We conclude that concentrations of procalcitonin
in the serum increase significantly in children following cardiac surgery, with
a peak at 48 hours, and do not return to baseline within 72 hours of surgery. A
proportion of patients, in the absence of infection, had exaggerated elevations
post-operatively.

J Thorac Cardiovasc Surg. 2006 Feb;131(2):336-42. 

Extensive deployment of the stented elephant trunk is associated with an
increased risk of spinal cord injury.

Flores J, Kunihara T, Shiiya N, Yoshimoto K, Matsuzaki K, Yasuda K.

Department of Cardiovascular Surgery, Hokkaido University Graduate School of
Medicine, Sapporo, Hokkaido, Japan.

OBJECTIVE: Thoracic aortic aneurysm repair with the stented elephant trunk
technique seems to be associated with an increased risk of spinal cord injury.
We investigated whether severe atherosclerosis of the distal landing zone or
extensive deployment of the stented elephant trunk is associated with increased
risk of spinal cord injury. METHODS: Twenty-five patients underwent thoracic
aortic aneurysm repair with the stented elephant trunk technique. The study
population included 19 men and had a mean age of 73 +/- 7 years. All patients
underwent a median sternotomy with cardiopulmonary bypass and selective cerebral
perfusion. The elephant trunk was fixed with a Z-stent distal to the aneurysm
during hypothermic circulatory arrest. Thirteen patients underwent concomitant
total aortic arch replacement. RESULTS: Six (24%) patients had spinal cord
injury. The presence of severe atherosclerosis at the distal landing zone
demonstrated a tendency to increase the incidence of spinal cord injury (36% vs
9%, P = .1218). More distal deployment of the stented elephant trunk was
significantly associated with increased risk of spinal cord injury (T8.0 +/- 0.6
vs T6.5 +/- 1.1, P = .0043). Univariate logistic regression analysis identified
a history of abdominal aortic aneurysm repair (P = .0296) and the vertebral
level of the distal landing zone (P = .0249) as significant independent risk
factors for spinal cord injury, and only the latter was significant in
multivariate analysis (P = .0396). The combination of a distal landing zone of
T7 or greater and a history of abdominal aortic aneurysm repair was the
strongest predictor for spinal cord injury (71% vs 6%, P = .0047). CONCLUSIONS:
Spinal cord injury after stented elephant trunk deployment might be related to
occlusion of the excessive intercostal arteries or thromboembolism. Patients
with a history of abdominal aortic aneurysm repair who require extensive
deployment of the stented elephant trunk seem to be at a higher risk for spinal
cord injury.

J Thorac Cardiovasc Surg. 2006 Feb;131(2):268-76. Epub 2006 Jan 18. 

Effect of closed minimized cardiopulmonary bypass on cerebral tissue oxygenation
and microembolization.

Liebold A, Khosravi A, Westphal B, Skrabal C, Choi YH, Stamm C, Kaminski A, Alms
A, Birken T, Zurakowski D, Steinhoff G.

Department of Cardiac Surgery, University of Rostock, Rostock, Germany.
andreas.liebold@med.uni-rostock.de

OBJECTIVE: Coronary artery bypass grafting with cardiopulmonary bypass carries a
risk for neurologic complications because of cerebral hypoperfusion and
microembolization. The basic goals of a novel closed minimized extracorporeal
circulation are to prevent excessive hemodilution and to avoid blood-air
interface. The aim of this prospective randomized study was to determine the
effect of using the minimized extracorporeal circulation system compared with
open conventional extracorporeal circulation on cerebral tissue oxygenation and
microembolization. METHODS: Forty patients undergoing coronary artery bypass
grafting (20 in each group) were continuously monitored for changes in cerebral
oxygenated hemoglobin and tissue oxygenation index by using near-infrared
spectroscopy. Total microembolic count and gaseous embolic count in both median
cerebral arteries were monitored with multifrequency transcranial Doppler
instrumentation. RESULTS: In the conventional extracorporeal circulation group
there was a highly significant reduction in both cerebral oxygenated hemoglobin
and tissue oxygenation index from the start to the end of cardiopulmonary bypass
(P < .01). The rate of decrease in cerebral oxygenated hemoglobin after aortic
cannulation was faster in the conventional extracorporeal circulation group (F
test = 9.03, P < .001). No significant changes with respect to cerebral
oxygenated hemoglobin or tissue oxygenation index occurred in the minimized
extracorporeal circulation group, except at the beginning of rewarming (P <
.01). Total embolic count, as well as gaseous embolic count, in the left and
right median cerebral arteries was significantly lower in the minimized
extracorporeal circulation group (all P < .05). Postoperative bleeding was
greater (P < .05) and the transfusion rate was higher (P < .05) in the
conventional extracorporeal circulation group. CONCLUSIONS: Use of closed
minimized cardiopulmonary bypass compared with conventional open cardiopulmonary
bypass preserves cerebral tissue oxygenation and reduces cerebral
microembolization.

Asian Cardiovasc Thorac Ann. 2006 Feb;14(1):51-6. 

Cardiopulmonary bypass without preoperative exchange transfusion in sicklers.

Maddali MM, Rajakumar MC, Fahr J, Albahrani MJ, Amna MA.

, Department of Anesthesia, Royal Hospital, PB No. 1331, PC. 111, Seeb, Muscat,
Sultanate of Oman. madan@omantel.net.om.

The effect of hypothermic cardiopulmonary bypass techniques on the sickling
process was evaluated in patients with sickle cell hemoglobin. It was presumed
that intraoperative hemolysis, as identified by hemoglobinuria, reflected
increased sickling. Data of 43 patients with sickle cell traits and 2 with
sickle cell disease, who were operated on under cardiopulmonary bypass and cold
cardioplegic arrest in a tertiary center from the beginning of 1995 to the end
of 2004, were retrospectively analyzed. A mean nasal temperature of 30.8 degrees
C +/- 2.1 degrees C was achieved. Three patients with sickle cell trait
developed intraoperative hemoglobinuria, albeit with normal surrogate values for
hemolysis. However, they had significantly lower mean hemoglobin levels during
cardiopulmonary bypass compared to those sickle cell patients who did not
exhibit hemoglobinuria (hemoglobin, 6.0 +/- 0.2 vs. 7.4 +/- 0.9 g.dL(-1), p <
0.01). Total drainage and blood transfusion requirements in patients with normal
and sickle cell hemoglobin were similar. It was concluded that hypothermic
cardiopulmonary bypass with cold cardioplegia is safe in sickle cell patients.
Maintenance of adequate hemoglobin levels during cardiopulmonary bypass may be
important to avoid triggering a sickling process.

Anesth Analg. 2006 Feb;102(2):352-62. 

Normothermic beating heart surgery with assistance of miniaturized bypass
systems: the effects on intraoperative hemodynamics and inflammatory response.

Rex S, Brose S, Metzelder S, de Rossi L, Schroth S, Autschbach R, Rossaint R,
Buhre W.

Department of Anesthesiology, Universitatsklinikum der RWTH, Aachen, Germany.
srex@ukaachen.de

The use of miniaturized cardiopulmonary bypass (CPB) circuits and avoidance of
cardioplegic arrest are attempts to reduce the inflammatory response to cardiac
surgery. We studied the effects of beating heart surgery (BHS) with assistance
of simplified bypass systems (SBS) on global hemodynamics, myocardial function
and the inflammatory response to CPB. We hypothesized that the use of SBS was
associated with less hemodynamic instability after CPB resulting from
attenuation of the inflammatory response when compared with surgery performed
with a conventional CPB (cCPB) circuit. Forty-five patients undergoing coronary
artery bypass grafting were prospectively studied. Fifteen patients were
randomized to the use of a cCPB circuit, cold crystalloid cardioplegia, and
moderate hypothermia. Two groups of 15 patients underwent BHS during
normothermia with assistance of two different SBS consisting of only blood pump
and oxygenator. Hemodynamic variables were assessed with transpulmonary
thermodilution and transesophageal echocardiography. Plasma levels of
proinflammatory and antiinflammatory mediators were measured perioperatively.
After CPB, variables of global hemodynamics and systolic ventricular function
did not differ among groups. Left ventricular diastolic function was impaired
after CPB equally in all groups (P < 0.01 versus pre-CPB). At the end of
surgery, there was more need for vasopressor (norepinephrine) support in both
SBS groups than in the cCPB group (P < 0.01). After CPB, the release of
interleukin (IL)-6 did not differ significantly among groups, whereas plasma
levels of IL-10 were higher in the cCPB group (P < 0.01 versus SBS). The extent
of myocardial necrosis (Troponin T) was comparable in all groups. We conclude
that in our study, miniaturizing bypass systems and avoidance of cardioplegic
arrest were not effective in improving hemodynamic performance and in
attenuating the proinflammatory immune response after CPB.

Ann Thorac Surg. 2006 Feb;81(2):474-80; discussion 480. 

Hypothermic low-flow cardiopulmonary bypass impairs pulmonary and right
ventricular function more than circulatory arrest.

Schultz JM, Karamlou T, Swanson J, Shen I, Ungerleider RM.

Division of Pediatric Cardiac Surgery, Doernbecher Children's Hospital, Oregon
Health and Science University, Portland, Oregon 97239-3098, USA.

BACKGROUND: Hypothermic circulatory arrest (HCA) is used during surgical
treatment of certain congenital heart defects. The possibility of ischemic
neurologic injury associated with HCA has led some surgeons to use low-flow
cardiopulmonary bypass (CPB) during the hypothermic interval (hypothermic low
flow [HLF]). This study investigates the inflammatory response to HCA and HLF,
and reports the consequences of this response on pulmonary and right ventricular
function. METHODS: Piglets (3.1 to 6.6 kg) were cooled to 16 degrees to 18
degrees C using CPB, and randomized: HCA for 60 minutes (n = 7), or HLF (50
cc.kg(-1).min(-1)) for 60 minutes (n = 6). The piglets were rewarmed to 36
degrees C and weaned from CPB. Serum tumor necrosis factor-alpha (TNF-alpha)
concentration, percent lung water, and pulmonary and cardiac function were
measured before and after CPB. RESULTS: Tumor necrosis factor-alpha was higher
after HLF (2,990.5 +/- 884.5 pg/mL), compared with HCA (347.6 +/- 89.2 pg/mL; p
= 0.03). The percent lung water was higher after HLF (84.8% +/- 0.3%) than HCA
(82.0% +/- 0.4%; p < 0.001). The alveolar to arterial oxygen gradient was worse
after HLF (457 +/- 42 mm Hg) than HCA (285.8 +/- 45 mm Hg; p = 0.02). Pulmonary
vascular resistance was greater after HLF (36.08 +/- 8.28 mm
Hg.mL(-1).m(-2).min(-1)) than HCA (14.55 +/- 3.46 mm Hg. mL(-1).m(-2).min(-1); p
= 0.049). The right ventricular pressure waveform peak derivative, corrected for
systolic pulmonary artery pressure, was lower after HLF (14.1 +/- 1.4 sec(-1)),
than HCA (23.8 +/- 2.7 sec(-1); p = 0.01). CONCLUSIONS: Hypothermic low flow
extends exposure to CPB, and is associated with an increased inflammatory
response compared with HCA. The greater inflammatory response after HLF may
result in substantial nonneurologic morbidity in the postoperative period,
demonstrated by pulmonary and right ventricular dysfunction. Interventions that
attenuate the inflammatory response to CPB may prevent pulmonary and right
ventricular dysfunction after HLF.

Eur J Cardiothorac Surg. 2006 Feb;29(2):168-74. Epub 2006 Jan 11. 

Brain oxygenation and metabolism during selective cerebral perfusion in
neonates.

Schears G, Zaitseva T, Schultz S, Greeley W, Antoni D, Wilson DF, Pastuszko A.

Department of Anesthesiology and Critical Care, Mayo Clinic, 200 First Street
SW, Rochester, MN 55905, USA.

OBJECTIVE: To investigate the possible neuroprotective effects of selective
cerebral perfusion (SCP) during deep hypothermic circulatory arrest on brain
oxygenation and metabolism in newborn piglets. METHODS: Newborn piglets 2-4 days
of age, anesthetized and mechanically ventilated, were used for the study. The
animals were placed on cardiopulmonary bypass, cooled to 18 degrees C and put on
SCP (20 ml/(kg min)) for 90 min. After rewarming, the animals were monitored
through 2h of recovery. Oxygen pressure in the microvasculature of the cortex
was measured by oxygen-dependent quenching of phosphorescence. The extracellular
level of dopamine in striatum was measured by microdialysis and hydroxyl
radicals by ortho-tyrosine levels. Levels of phosphorylated cAMP response
element binding protein (pCREB) in striatal tissue were measured by Western
blots using antibodies specific for phosphorylated CREB. The results are
presented as mean+/-SD (p<0.05 was significant). RESULTS: Pre-bypass cortical
oxygen pressure was 48.9+/-11.3 mmHg and during the first 5 min of SCP, the peak
of the histogram, corrected to 18 degrees C, decreased to 11.2+/-3.8 mmHg
(p<0.001) and stayed near that value to the end of bypass. The mean value for
the peak of the histograms measured at the end of SCP was 8+/-3 mmHg (p<0.001).
SCP completely prevented the deep hypothermic circulatory arrest-dependent
increase in extracellular dopamine and hydroxyl radicals. After SCP, there was a
statistically significant increase in pCREB immunoreactivity (534+/-60%)
compared to the sham-operated group (100+/-63%, p<0.005). Measurements of total
CREB showed that SCP did induce a statistically significant increase in CREB as
compared to sham-operated animals (168+/-31%, p<0.05). CONCLUSION: SCP, as
compared to DHCA, improved cortical oxygenation and prevented increases in the
extracellular dopamine and hydroxyl radicals. The increase in pCREB in the
striatum following SCP may contribute to improved cellular recovery after this
procedure.

Eur J Cardiothorac Surg. 2006 Feb;29(2):175-80.  

Residual air in the venous cannula increases cerebral embolization at the onset
of cardiopulmonary bypass.

Rodriguez RA, Rubens F, Belway D, Nathan HJ.

Department of Surgery, Division of Cardiac Surgery, University of Ottawa Heart
Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7.
Rrodriguez@Ottawaheart.ca

OBJECTIVE: When the right atrium (RA) cannula is connected to the venous return
line of the cardiopulmonary bypass (CPB) circuit, air is often introduced. Air
in the venous cannula may increase cerebral air embolization at initiation of
CPB despite the arterial line filter. We measured the volume of air present in
the venous cannula after cannulation of the RA. Transcranial Doppler quantified
emboli as high-intensity transient-signals (HITS) in both middle-cerebral
arteries (MCA) at the beginning of CPB. METHODS: After RA cannulation, the air
column in the venous line was measured and the total volume calculated using the
known lumen diameter. CPB onset was defined as the instant when the CPB machine
started moving the patient's blood from the RA into the venous reservoir.
Starting from CPB onset, HITS were counted: (a) until completion of the first
minute on CPB (1-min count) and (b) until aortic cross clamping (pre-clamping
count). RESULTS: We studied 135 patients during coronary artery bypass surgery
operated on by 10 cardiac surgeons. HITS during onset of CPB were detected in
95% of patients. Median counts were 10 HITS (25th, 75th percentiles: 3, 26) at
1-min and 21 HITS (8, 51) during pre-clamping. A significant correlation was
found between the volume of air in the venous cannula and the HITS counts
(r=0.524, p<0.0001). Absence of retained air was associated with lower HITS
counts [3 HITS (1, 11)] compared with any amount of air [13 HITS (4, 29),
p=0.002)]. The volume of air in the venous cannula, the MCA mean blood flow
velocity and the pre-clamping time were the only independent predictors of the
pre-clamping HITS counts (p<0.001). CONCLUSION: Air in the venous cannula can
result in HITS in the MCA. Minimizing the volume of air introduced into the
venous cannula after cannulation of the RA can decrease cerebral air
embolization at the beginning of CPB.

Arch Dis Child. 2006 Feb;91(2):117-20. Epub 2005 Dec 2. 

Procalcitonin does discriminate between sepsis and systemic inflammatory
response syndrome.

Arkader R, Troster EJ, Lopes MR, Junior RR, Carcillo JA, Leone C, Okay TS.

Laboratory of Medical Investigation-LIM/36-Department of Pediatrics, School of
Medicine, University of Sao Paulo, Brazil.

AIMS: To evaluate whether procalcitonin (PCT) and C reactive protein (CRP) are
able to discriminate between sepsis and systemic inflammatory response syndrome
(SIRS) in critically ill children. METHODS: Prospective, observational study in
a paediatric intensive care unit. Kinetics of PCT and CRP were studied in
patients undergoing open heart surgery with cardiopulmonary bypass (CPB) (SIRS
model; group I1) and patients with confirmed bacterial sepsis (group II).
RESULTS: In group I, PCT median concentration was 0.24 ng/ml (reference value
<2.0 ng/ml). There was an increment of PCT concentrations which peaked
immediately after CPB (median 0.58 ng/ml), then decreased to 0.47 ng/ml at 24 h;
0.33 ng/ml at 48 h, and 0.22 ng/ml at 72 h. CRP median concentrations remained
high on POD1 (36.6 mg/l) and POD2 (13.0 mg/l). In group II, PCT concentrations
were high at admission (median 9.15 ng/ml) and subsequently decreased in 11/14
patients who progressed favourably (median 0.31 ng/ml). CRP levels were high in
only 11/14 patients at admission. CRP remained high in 13/14 patients at 24 h;
in 12/14 at 48 h; and in 10/14 patients at 72 h. Median values were 95.0, 50.9,
86.0, and 20.3 mg/l, respectively. The area under the ROC curve was 0.99 for PCT
and 0.54 for CRP. Cut off concentrations to differentiate SIRS from sepsis were
>2 ng/ml for PCT and >79 mg/l for CRP. CONCLUSION: PCT is able to differentiate
between SIRS and sepsis while CRP is not. Moreover, unlike CRP, PCT
concentrations varied with the evolution of sepsis.