Advertisement
+ News Categories + Corporate Categories + Report Categories

Does Modified Ultrafiltration Improves Inflammatory Response and Cardiopulmonary Function After CABG Procedures?

Summary

The inflammatory response after cardiac surgery increases mortality and morbidity. Modified
ultrafiltration (MUF) has been shown to decrease the post-cardiac surgery inflammatory
response, to improve respiratory function, and cardiac performance in pediatric patients;
however, this approach has not been well established in adults. The investigators therefore
hypothesized that MUF can decrease the post-cardiac surgery inflammatory response and can
improve cardiopulmonary function in adults.

Description

Patient selection After Institutional Review Board approval, a prospective study was carried
out with 60 consecutive patients underwent CABG cardiopulmonary bypass (CPB) in our
institution. All patients signed a consent form before enrolled into the study. The patients
were randomly assigned to a control group treated with no modified ultrafiltration (CO
group) or to a treatment group with modified ultrafiltration (MUF group) after bypass
period. The inclusion criteria were: patients aged from 30 to 70 years old, both genders,
left ventricle ejection fraction higher than 39%, normal renal function, with or without
diabetes, and who underwent CABG with no associate procedures. The exclusion criteria were:
left ventricle ejection fraction lower than 39% and abnormal renal function (serum
creatinine > 2.0 mg/dl, clearance lower than 45 mL/m in males or lower than 40 mL/m in
females).

Surgical procedure:

After anesthesia induction, the patients were monitored using a continuous cardiac output
catheter (Edwards Lifesciense, Irvine. USA), invasive arterial mean pressure catheter, and
urine output catheter.

All patients were submitted to tepid bypass (32 o C) with a target flow of 2.4 L/min/m2.
After CPB was established the aorta was cross clamped and the distal anastomoses were
performed. The blood tepid cardioplegia were used during the cross clamp period. The clamp
was released and a C-clamp was applied for the proximal anastomosis effectuation. After a
proximal anastomosis complementation, the patients were weaned from the bypass. Following
the CPB period the patients were randomly assigned to MUF group or CO group. All operations
were performed by one surgeon (O.P.).

Modified Ultrafiltration. The ultrafiltration was performed in heparinized patients between
the arterial and the venous tubings of the CPB circuit, using a H-500 filter
(polyestersuphone) with an effective membrane area of 0.5 m2, pore size of 5 nm, prime
volume of 34 ml, maximum transmembrane pressure of 400 mmHg, internal fiber diameter of 200
µm, and fiber thickness wall of 30 µm (Braile Biomedica, São José do Rio Preto, Brazil).

The blood flow through the filter was 300 ml/min, which as maintained by a roller pump on
the inlet part of the filter. Suction was applied to the filtrate port to achieve a negative
pressure of 100 mmHg. The process was carried out for 15 minutes in all patients who
underwent MUF while the patients assigned to CO group were observed for 15 minutes.

The hemostasis was reviewed, a mediastinal drain was inserted, the patient was closed, and
sent to the intensive care unit.

Blood sample, oxygen transport, and hemodynamic parameters regimen:

The hemodynamic and oxygen transport parameters such as cardiac output index, systemic
vascular resistance index, pulmonary vascular resistance index, arterial mean pressure,
oxygen delivery (DO2), oxygen consumption (VO2), oxygen index (OI), and alveolar-arterial
gradient (A-aDO2) were recorded.

The oxygen index was calculated by the following equation: OI = (FiO2 X MAP)/PaO2. The
A-aDO2 were calculated by the equation: A-aDO2 = 713 X FiO2 - PaO2 - PaCO2). Where FiO2 is
inspired fraction of oxygen, MAP is mean airway pressure, PaO2 is partial pressure of oxygen
in the arterial blood, and PaCO2 is partial pressure of carbon dioxide in the arterial
blood.

Blood samples were collected from arterial line with heparin coated tubes for interleukin 6
(IL-6), P-selectin, E-selectin, and intercellular adhesion molecule (ICAM) determination at
the following times: after induction of anesthesia, pre MUF after bypass, post MUF, 24 hours
after surgery, and 48 hours after of surgery. Blood samples were centrifuged for 20 minutes
at 4oC and the serum was aliquoted and stored at - 70oC. The inflammatory markers were
measured using commercially available ELISA kits (R&D Systems, Abingdon, UK).

Clinical variables:

Patients demographic data and medical history were collected prospectively. Postoperative
data such as ICU length of stay (days), hospital length of stay (days), total blood loss in
48 hours, units of red blood cell transfusions, serum creatinine, international normalized
ratio for prothrombin time (INR), partial thromboplastin time ratio (PR), leukocytes count,
serum lactate, and urea nitrogen (BUN) were also recorded.

Statistical analyzes The continuous variables were expressed as mean with one standard
deviation, the categorical variables were expressed as frequency. All data were tested for
normality and the necessary transformations were performed as necessary. The t test for
unpaired samples was used for total bleeding and requirements of RBC units transfusion
analysis. The two-way ANOVA was performed for intragroup, intergroup, and time/group
interactions with Bonferroni post-hoc test (GraphPad Prism version 5.0 for Mac OS X. San
Diego California. USA). The P-values < 0.05 were considered statistically significant.

Study Design

Allocation: Randomized, Control: Placebo Control, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Outcomes Assessor), Primary Purpose: Treatment

Conditions

Coronary Artery Disease

Intervention

Modified Ultrafiltration

Location

Hospital da Clinicas
Campinas
Sao Paulo
Brazil
13100000

Status

Completed

Source

University of Campinas, Brazil

Results (where available)

View Results

Links

MESH Definitions

Coronary Artery Bypass

Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion.

Internal Mammary-coronary Artery Anastomosis

Direct myocardial revascularization in which the internal mammary artery is anastomosed to the right coronary artery, circumflex artery, or anterior descending coronary artery. The internal mammary artery is the most frequent choice, especially for a single graft, for coronary artery bypass surgery.

Coronary-subclavian Steal Syndrome

A complication of INTERNAL MAMMARY-CORONARY ARTERY ANASTOMOSIS whereby an occlusion or stenosis of the proximal SUBCLAVIAN ARTERY causes a reversal of the blood flow away from the CORONARY CIRCULATION, through the grafted INTERNAL MAMMARY ARTERY (internal thoracic artery), and back to the distal subclavian distribution.

Ultrafiltration

The separation of particles from a suspension by passage through a filter with very fine pores. In ultrafiltration the separation is accomplished by convective transport; in DIALYSIS separation relies instead upon differential diffusion. Ultrafiltration occurs naturally and is a laboratory procedure. Artificial ultrafiltration of the blood is referred to as HEMOFILTRATION or HEMODIAFILTRATION (if combined with HEMODIALYSIS).

Coronary Artery Disease

Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.

 Clinical Trials 1500 Associated Clinical Trials :: Search

 PubMed Articles 11185 Associated PubMed Articles :: Search

Advertisement

Associated Content for this Trial

Advertisement

Searches Linking to this Page

inflammatory response syndrome after cabg