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| 1 |
TITLE: Difficult separation from cardiopulmonary bypass and deltaPCO2.
AUTHORS: Denault A; Belisle S; Babin D; Hardy JF
AUTHOR AFFILIATION:
Department of Anesthesiology, Research Center, Montreal Heart
Institute, Quebec, Canada. denault@videotron.ca
PUBLICATION TYPES:
Journal Article
LANGUAGES:
eng
ABSTRACT:
PURPOSE: Veno-arterial and regional differences of the partial
pressure in CO2 (deltaPCO2), may be used as index to evaluate the
adequacy of the cardiac output to the oxygen consumption. To
determine the incidence of elevated deltaPCO2 and its relationship
with difficult separation from bypass (DSB) in patients undergoing
cardiac surgery, we conducted a prospective observational cohort
study. METHODS: Data were collected from 58 consecutive patients
undergoing various cardiac operations requiring cardiopulmonary
bypass (CPB). During the procedure, arterial and venous blood gases
and lactate were sampled. Blood was drawn after induction of
anesthesia, during bypass and at the closure of the chest wall.
Difficult separation from bypass was defined as a systolic arterial
pressure < 80 mmHg, and diastolic pulmonary artery pressure >
15 mmHg during progressive separation from CPB with inotropic or
mechanical support of cardiac function, or hemodynamic instability
resulting in reintroduction of extra-corporeal circulation or
insertion of an intra-aortic balloon pump. RESULTS: In our study, 65%
of the samples were associated with elevated deltaPCO2 (> 6 mmHg).
Variables associated with difficult weaning were LVEF; duration of
bypass and aortic cross-clamping, pre-bypass deltaPCO2 and in-bypass
lactate values (P < 0.05). Multivariable analysis identified the
pre-bypass deltaPCO2 and the duration of bypass as predictors of DSB.
CONCLUSION: Elevated deltaPCO2 is frequently observed during cardiac
surgery and values obtained before bypass were associated with DSB.
The deltaPCO2 gradients could be used as marker of the adequacy of
tissue perfusion during cardiac surgery.
NLM PUBMED CIT. ID:
11220431
SOURCE: Can J Anaesth 2001 Feb;48(2):196-9.
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| 2 |
TITLE: Comparison of three commercially available hollow fiber oxygenators:
gas transfer performance and biocompatibility.
AUTHORS: de Vroege R; Wagemakers M; te Velthuis H; Bulder E
Paulus R; Huybregts R; Wildevuur W; Eijsman L; van Oeveren W
Wildevuur C
AUTHOR AFFILIATION:
Department of Extracorporeal Circulation, University Hospital Vrije
Universiteit, Amsterdam, The Netherlands.
PUBLICATION TYPES:
Journal Article
LANGUAGES:
eng
ABSTRACT:
The new generation of oxygenators have improved blood flow pathways
that enable reduction in priming volume and, thus, hemodilution
during cardiopulmonary bypass (CPB). We evaluated three oxygenators
and two sizes of venous reservoirs in relation to priming volume, gas
transfer, and blood activation. To compare priming volume, gas
transfer, and biocompatibility of three hollow fiber oxygenators and
two different size venous reservoirs, 60 patients were randomly
allocated in groups to undergo cardiopulmonary bypass. In each group,
an oxygenator with a different surface area and priming volume was
used: 1.8 m2 and 220 ml (group 1, n = 23), 2.2 m2 and 290 ml (group
2, n = 20), and 2.5 m2 and 270 ml (group 3, n = 17). In groups 1 and
3, a large soft shell (1900 ml) venous reservoir was used, whereas in
group 2, a smaller soft shell (600 ml) venous reservoir was used. Gas
transfer was assessed by calculating the oxygen transfer rate for
each group and per square meter for each oxygenator group. Partial
arterial oxygen pressure (paO2) and partial arterial carbon dioxide
pressure (paCO2) between the groups were assessed with forward
stepwise regression analysis. Biocompatibility was evaluated through
measurement of platelet numbers, complement activation products
(C3b/c), coagulation (thrombin anti-thrombin III complex), and
fibrinolysis (plasmin anti-plasmin complex). No differences were
found in oxygen transfer rate per group. However, when correcting the
oxygen transfer rate for surface area, group 1 demonstrated a higher
oxygen transfer rate compared with group 2 (p < 0.05) at an FiO2
of 40 and 60% and compared with group 3 at an FiO2 of 60 and 70%. The
regression analysis showed that the average arterial PO2 was the
highest in group 3, i.e., 79.2 mm Hg higher than in group 1 (p <
0.001) and 73.5 mm Hg higher than in group 2 (p < 0.001). Group 3
also had the lowest average arterial pCO2, 0.57 mm Hg lower than in
group 1 (p = 0.004) and 0.81 mm Hg lower than in group 2 (p <
0.001). During CPB, platelet numbers decreased significantly in all
groups (p < 0.001), without differences between the groups. C3b/c
levels increased in all groups during CPB. At cessation of CPB the
C3b/c level in group 2 (398 nmol/L(-1)) was significantly higher
compared to group 1(251 nmol/L(-1); p < 0.05) and group 3 (303
nmol/L(-1); p < 0.05). Thrombin anti-thrombin III complexes and
plasmin anti-plasmin complex complexes increased during CPB to
significantly high levels at cessation of CPB, but there were no
differences between the groups. The oxygenator with the smallest
surface area and lowest priming volume (group 1) had the highest
oxygen transfer rate per square meter and showed the least blood
damage, as depicted by complement activation. The oxygenator with the
largest blood contact surface area and improved geometric
configuration (group 3) showed the lowest oxygen transfer rate per
square meter. However, this oxygenator elevated oxygen partial
pressure the most and reduced carbon dioxide partial pressure the
most. In group 2, where a smaller venous reservoir was used, the
highest blood activation was observed.
NLM PUBMED CIT. ID:
11199313
SOURCE: ASAIO J 2001 Jan-Feb;47(1):37-44.
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| 3 |
TITLE: Comparison of tumor necrosis factor-alpha effect on the expression of
iNOS in macrophage and cardiac myocytes.
AUTHORS: Sanders DB; Larson DF; Hunter K; Gorman M; Yang B
AUTHOR AFFILIATION:
Circulatory Sciences Graduate Perfusion Program, Sarver Heart Center,
University of Arizona, Tucson 85724, USA.
PUBLICATION TYPES:
Journal Article
LANGUAGES:
eng
ABSTRACT:
Proinflammatory cytokines, including tumor necrosis factor-alpha
(TNF-alpha), are elevated during cardiopulmonary bypass (CPB), heart
failure, and inflammatory cardiac and systemic diseases. Elevated
TNF-alpha has been linked to diminished cardiac function, decreased
systemic vascular resistance, as well as renal and pulmonary
dysfunction. It is understood that myocardial tissues can express
TNF-alpha, which results in the induction of inducible nitric oxide
synthase (iNOS) leading to a significant decline in cardiac function
and other direct effects. The hypothesis of this study was to
determine if TNF-alpha would stimulate iNOS and its product nitric
oxide (NO) similarly in immortalized macrophage and cardiac myocytes.
Cultured macrophages (RAW 264.7) and cardiac myocytes (HL-1) were
placed into two treatment groups and a control. The treatments
included: (1) TNF-alpha and lipopolysaccharide (LPS); and (2) LPS,
TNF-alpha, interleukin-1beta (IL-1beta) and interferon-gamma
(IFN-gamma) incubated for 8 h. The macrophage expression of iNOS
increased by 365% (p < 0.01) and its product, NO, increased
proportionally. The expression of iNOS in the cardiac myocyte did not
increase with TNF-alpha and LPS. However, with the addition of
IFN-alpha and IL-1beta iNOS increased to 140% of control (p <
0.05). Myocyte cGMP and NO did not increase significantly with
TNF-alpha treatment. This study suggests that HL-1 myocyte iNOS
cannot be induced by TNF-alpha, unlike macrophage iNOS. Furthermore,
the resultant cardiac dysfunction, secondary to proinflammatory
cytokines effects, is regulated via diverse pathways.
NLM PUBMED CIT. ID:
11192310
SOURCE: Perfusion 2001 Jan;16(1):67-74.
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| 4 |
TITLE: Does heparin pretreatment affect the haemostatic system during and
after cardiopulmonary bypass?
AUTHORS: Brinks HJ; Weerwind PW; Bogdan S; Verbruggen H
Brouwer MH
AUTHOR AFFILIATION:
Department of Extracorporeal Circulation, University Medical Centre
St. Radboud, Nijmegen.
PUBLICATION TYPES:
Journal Article
LANGUAGES:
eng
ABSTRACT:
In this clinical pilot study, the influence of heparin pretreatment on
the haemostatic system during and after cardiopulmonary bypass (CPB)
was investigated. Thirteen patients scheduled for elective coronary
artery bypass grafting (CABG) were divided into two groups: heparin
pretreated (HP, n = 6) and non-heparin pretreated (NHP, n = 7). Blood
samples were taken for measurements of plasma antithrombin-III
(AT-III) activity, plasma heparin levels, activated clotting time
with (HACT) and without (ACT) heparinase, whole blood platelet
function, platelet count, thrombin-antithrombin-III complexes and
D-dimer levels. Also, the mediastinal blood loss within the initial
20 h after surgery, and the blood transfusion requirements were
monitored. The mean duration of the heparin pretreatment was 55 h
(range 24-161 h). There was no significant difference in plasma
AT-III activity and platelet count between the groups. Before and
after CPB, the platelet responsiveness was better in the NHP group (p
< 0.05). The HACT was prolonged in the NHP group during and after
CPB compared to baseline values (p < 0.05), whereas, in the HP
group, no significant changes were found. Plasma heparin levels and
ACT values suggested adequate anticoagulation during CPB. However,
the extent of thrombin inhibition and fibrinolysis increased with
time on CPB, but did not differ between the two groups. Twenty hours
after surgery, the thrombin inhibition showed to be significantly
higher in the NHP group. Furthermore, mediastinal blood loss showed a
tendency to be lower in the HP group (p = 0.08). However, there was
no difference in blood transfusion requirements between the groups.
These data suggest that short-term heparin pretreatment affects the
perioperative platelet responsiveness and attenuates the consumption
of coagulation factors.
NLM PUBMED CIT. ID:
11192305
SOURCE: Perfusion 2001 Jan;16(1):3-12.
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| 5 |
TITLE: An alternative application of sodium nitroprusside to overcome
perioperative spasm of the internal thoracic artery.
AUTHORS: Yorgancioglu C; Tokmakoglu H; Gunaydin S; Catav Z
Suzer K
AUTHOR AFFILIATION:
Bayindir Medical Center, Department of Cardiovascular Surgery,
Sogutozu, 06520, Ankara, Turkey
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
ENG
ABSTRACT:
Objective: The internal thoracic artery (ITA) is currently the
preferred conduit for myocardial revascularization; however,
perioperative vasospasm of the internal thoracic artery may cause
morbidity. Pedicle preparation and pharmacological vasodilatory
treatment vary greatly. This clinical study was performed in order to
define the effectiveness of two different applications of sodium
nitroprusside as vasodilating agent.Methods: Eighty-six (86)
consecutive patients whose left internal thoracic artery was
mobilized only by one surgeon for elective coronary artery bypass
graft operations were randomly divided into two groups. The internal
thoracic artery was allowed to bleed freely, and the flow was
determined (flow 1). In group I (n=42) 3mg sodium nitroprusside in
10ml of 5% dextrose solution was sprayed with pressure on the pedicle
with a thin 25 gauge needle. In group II (n=44) half of the solution
was sprayed in the same manner, and the other half of the solution
was injected into the pedicle in the periarterial tissue along the
length of the pedicle. Free flows of the internal thoracic artery
were registered before cardiopulmonary bypass (flow 2) and also just
prior to performing internal thoracic artery anastomosis to the left
anterior descending artery (flow 3). With each measurement
hemodynamic parameters and the time between measurements were
recorded.Results: No statistically significant differences were found
between the groups in respect to sex ratio, age, body surface area,
heart rate 1 and 2, mean arterial pressure 1 and 3. There was no
significant difference in the initial flow among groups. Significant
differences were noted in the second flow measurement (P<0.05) and
in the third flow measurement (P<0.01) between two groups. For
each group there was a significant increase in flow from flow 1 to
flow 2 and from flow 2 to flow 3 (P<0.02).Conclusion: Sodium
nitroprusside injection to the pedicle provides a better flow than
simple spraying of the same agent.
NLM PUBMED CIT. ID:
11137810
SOURCE: Cardiovasc Surg 2001 Feb;9(1):64-67.
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| 6 |
TITLE: Low preoperative antithrombin activity causes reduced response to
heparin in adult but not in infant cardiac-surgical patients.
AUTHORS: Dietrich W; Braun S; Spannagl M; Richter JA
AUTHOR AFFILIATION:
Department of Anesthesiology, German Heart Center, Munich, Germany.
dietrich@dhm.mhn.de
PUBLICATION TYPES:
Journal Article
LANGUAGES:
eng
REGISTRY NUMBERS:
0 (Anticoagulants)
0 (Antithrombins)
9005-49-6 (Heparin)
ABSTRACT:
We evaluated the interaction of preoperative antithrombin (AT)
activity and intraoperative response to heparin in cardiac surgery.
Heparin anticoagulation is essential during cardiopulmonary bypass
(CPB). Heparin itself has no anticoagulant properties, however it
causes a conformational change of the physiologic plasma inhibitor AT
that converts this slow-acting serine protease inhibitor into a fast
acting one. Thus, adequate AT activity is a prerequisite for
sufficient heparin anticoagulation. AT activity is reduced by
long-term heparin therapy. This prospective, observational study
investigated 1516 consecutive cardiac-surgical patients (1304
patients >1 yr (Group A) and 212 patients < or = 1 yr (Group
I)). AT activity was measured the day before surgery by a chromogenic
substrate assay. The celite-activated activated clotting time (ACT)
was used to guide intraoperative heparin administration. Heparin
sensitivity was calculated and the postoperative blood loss and
perioperative blood requirement was recorded. Infant patients had
significantly less preoperative AT activity compared with older
patients: 84 (33)% vs 97 (17)%, median (interquartile range) (P <
0. 05). The subgroup of patients aged <1 mo (n = 64) demonstrated
a preoperative AT activity of 56 (27)% as compared with 90 (23)% in
infant patients between one month and one year (n = 148). In adult
patients, preoperative AT activity depended predominantly on
preoperative heparin treatment: 62% of the patients with an AT
activity <80% were pretreated with heparin. Five minutes after
heparin but before CPB the ACT was 587 (334) s in Group A patients
with AT activity > or = 80%, and 516 (232) in patients with AT
activity < or = 80% (P < 0.05). The target ACT of 480 s was
achieved in 70% of patients with normal AT activity in Group A
compared with only 54% of patients with AT activity <80% (P <
0.05). In Group A patients with decreased AT activity, 18%
demonstrated an inadequate ACT response-defined as ACT <400 s-to
the first bolus injection of heparin. In Group I, preoperative AT
activity did not influence the ACT response (ACT 5 min after heparin:
846 [447] s in patients with AT activity > or = 80% vs 1000 [364]
s in patients with decreased AT activity). The heparin sensitivity
was 2.4 (1.1) s/unit heparin/kg compared with 1.5 (0.8) s/unit
heparin/KG in group A (P < 0.05). These results suggest that
preoperative diminished AT activity causes reduced response to
heparin in adult but not in infant patients. Infant patients
demonstrate a higher heparin sensitivity despite lower preoperative
AT activity. Measurement of preoperative AT activity identifies adult
patients at risk of reduced sensitivity to heparin. Implications: In
patients less than one year of age, low antithrombin (AT) activity is
caused by the immature coagulation system. Despite low AT activity,
these young patients demonstrate a normal or increased response to
heparin anticoagulation before cardiopulmonary bypass (CPB). In
contrast, in patients older than one year of age and adult patients
decreased preoperative AT activity is mainly caused by preoperative
heparin therapy and causes insufficient response to heparin
anticoagulation with a standard heparin dosage. Measurement of
preoperative AT activity identifies patients at risk of inadequate
anticoagulation during CPB.
NLM PUBMED CIT. ID:
11133602
SOURCE: Anesth Analg 2001 Jan;92(1):66-71.
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| 7 |
TITLE: Oxygen free radical generation in healthy blood donors and cardiac
patients: the protective effect of allopurinol.
AUTHORS: Belboul A; Roberts D; Borjesson R; Johnsson J
AUTHOR AFFILIATION:
Department of Thoracic and Cardiovascular Surgery, Sahlgrenska
University Hospital, Goteborg, Sweden.
PUBLICATION TYPES:
Journal Article
LANGUAGES:
eng
ABSTRACT:
Cardiopulmonary bypass (CPB) activates the complement system, which
leads to granulocyte activation and free radical production. Free
radical activity during CPB has been associated with myocardial
dysfunction. However, the relationship between cardiac enzymes and
granulocytes to lipid peroxidation in cardiac surgery patients is
unknown. Moreover, the effect of allopurinol on lipid peroxidation
during mechanical trauma has to be explored. Thirty-four patients
undergoing coronary bypass surgery and 26 healthy blood donors
participated in this prospective study where granulocyte counts,
cardiac enzymes and malondialdehyde (MDA) were measured and related.
Allopurinol was used ex vivo, as scavenger, to explore its effect on
lipid peroxidation. In the patient group, the mean preoperative MDA
level (2.2 +/- 0.7, nmol/ml) significantly increased after 30 min of
bypass (3.3 +/- 0.9 nmol/ml; p < 0.0001), and showed a second peak
at aortic declamping (4.1 +/- 0.9 nmol/ml). There were significant
correlations between MDA and granulocyte counts (r = 0.59, p <
0.0001) and cardiac enzymes (r = 0.55, p < 0.0001). In an ex vivo
setting, further mechanical trauma to blood significantly increased
the MDA levels, both in the control (p < 0.0001) and in the
patient group (p < 0.0001) and this effect could be reduced by
allopurinol (p < 0.0001). CPB and mechanical trauma generate
oxygen free radicals. Allopurinol was found to reduce lipid
peroxidation of red cells following mechanical trauma and this has to
be further investigated regarding its ability to reduce morbidity in
patients undergoing open heart surgery.
NLM PUBMED CIT. ID:
11192309
SOURCE: Perfusion 2001 Jan;16(1):59-65.
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| 8 |
TITLE: [Efficacy of modified ultrafiltration in reoperation for valvular
disease]
AUTHORS: Kamada M; Niibori K; Akimoto H; Yokoyama H
Tofukuji M; Iguchi A; Ohmi M; Tabayashi K; Kikuchi S; Matsuura T
AUTHOR AFFILIATION:
Department of Cardiovascular Surgery, Tohoku University Graduate
School of Medicine, Sendai, Japan.
PUBLICATION TYPES:
Journal Article
LANGUAGES:
jpn
ABSTRACT:
We evaluated the efficacy of modified ultrafiltration (MUF) in
reoperation for valvular disease. Fourteen patients were divide into
two groups consisting of a control group (n = 6) and a MUF group (n =
8). MUF was carried out for fifteen minutes immediately after the
completion of cardiopulmonary bypass. The blood flow through the
ultrafilter was 300 ml/min and about 1,200 ml of water was removed.
The hematocrit elevated significantly from 25% to 31% in the MUF
group (p < 0.05). The percentage of the increase in body weight
after the operation in the MUF group was significantly less than that
in the control group (3.3 +/- 3.1% vs 8.3 +/- 4.3%, p < 0.05). The
PaO2/FIO2 after the operation in the MUF group was significantly
higher than that in the control group (376 +/- 125 mmHg vs 242 +/- 79
mmHg, p < 0.05). The duration of mechanical ventilation in the MUF
group was significantly less than that in the control group (1.1 +/-
1.1 days vs 5.3 +/- 3.3 days, p < 0.05). In conclusion, MUF is
useful to hemoconcentrate, reduce postoperative body weight gain and
promote early recovery of pulmonary function in reoperation for
valvular disease.
NLM PUBMED CIT. ID:
11211764
SOURCE: Kyobu Geka 2001 Feb;54(2):119-24.
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| 9 |
TITLE: Comparison of the flow capacity of free arterial grafts and saphenous
vein grafts for coronary bypass surgery.
AUTHORS: Hall TS; Ferguson J; Sines J; Spotnitz AJ
AUTHOR AFFILIATION:
University of California, San Francisco and The Robert Wood Johnson
Medical School, USA
PUBLICATION TYPES:
JOURNAL ARTICLE
LANGUAGES:
ENG
ABSTRACT:
There is controversy regarding the flow reserve and capacity of
arterial conduits to meet the needs of the myocardium. This study
compared flow in 22 free arterial bypasses to 15 saphenous vein
grafts in procedures involving twenty patients. To assess the maximal
flow possible, (flow capacity) graft flow was measured using a
calibrated pump while perfusing blood cardioplegia through the
conduit and distal anastomosis during cardiac arrest (no competitive
flow). This assessment was subsequently confirmed with whole blood
during myocardial contraction while on cardiopulmonary bypass.
Twenty-two free arterial grafts were used; 15 right internal mammary
artery grafts, 4 right gastroepiploic grafts, 3 inferior epigastric
artery grafts, and 3 sequential bypasses. Free arterial conduit flow
ranged from 50 to 180cc/ml, with an average flow of
102.5+/-28.5ml/min as compared to saphenous vein graft flow, 102+/-28
ml/min. No correlation of flow with the conduit size was found.
Arterial graft flow demonstrated a mild correlation with the size of
the native coronary artery bypassed (R=0.47,
P</=0.02).Conclusions: Basal flow through free arterial grafts is
equivalent to saphenous vein grafts and is primarily determined by
the native coronary vessels. The flow reserve for free arterial
conduits is more than adequate for coronary bypass surgery.
NLM PUBMED CIT. ID:
11137805
SOURCE: Cardiovasc Surg 2001 Feb;9(1):27-32.
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| 10 |
TITLE: Leucodepletion during cardiopulmonary bypass reduces blood transfusion
and crystalloid requirements.
AUTHORS: Stefanou DC; Gourlay T; Asimakopoulos G; Taylor KM
AUTHOR AFFILIATION:
Department of Cardiothoracic Surgery, National Heart and Lung
Institute, Imperial College School of Medicine, London, UK.
PUBLICATION TYPES:
Journal Article
LANGUAGES:
eng
ABSTRACT:
Cardiopulmonary bypass (CPB) is associated with the production of
inflammatory responses, which can have significant influence on
prognosis. We studied the effects of leucocyte-depletion filters on
inflammatory parameters and early postoperative prognosis during
coronary revascularization. Twenty patients undergoing elective
coronary revascularization were randomly divided into two groups. Ten
patients had leucocyte-depletion filters added to the CPB circuit
(treatment group) and 10 were used as control cases (control group).
Expression of CD11b on neutrophils, and production of myeloperoxidase
and lactoferrin, were measured in arterial samples between induction
and 3 h postbypass. In addition, clinical parameters were measured
during inpatient recovery. CD11b neutrophil expression, and
myeloperoxidase and lactoferrin production, were found to be
upregulated during CPB and then to decline to preoperative levels by
the third postoperative hour. Blood transfusion requirements were
reduced in the treatment group, equalling 1.5 +/- 1.2 units, compared
to 2.7 +/- 1.1 units for the control group (p value = 0.034) and so
were the volumes of crystalloid infused during the first 24 h
postoperatively, equalling 3.9 +/- 1.21 in the treatment group and
3.3 +/- 0.71 in the control group (p value = 0.021). Overall, the
application of leucocyte depletion produced an early clinical
advantage, underlining the need for an improved understanding and
manipulation of the inflammatory response to CPB.
NLM PUBMED CIT. ID:
11192308
SOURCE: Perfusion 2001 Jan;16(1):51-8.
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