336 Plasma Nitrate/Nitrite (NOx) Is Not a Useful Biomarker to Predict Inherent Cardiopulmonary Bypass Inflammatory Response Fernanda Viaro, B.Sc., Caroline Floreoto Baldo, V.M.D., Verena Kise Capellini, B.Sc., Andrea Carla Celotto, B.Sc., Solange Bassetto, M.D., Alfredo Jos ´ e Rodrigues, M.D., Ph.D., and Paulo Roberto Barbosa Evora, M.D., Ph.D. Division of Thoracic and Cardiovascular Surgery, Department of Surgery and Anatomy, Ribeir ˜ ao Preto Faculty of Medicine,University of S ˜ ao Paulo, Ribeir ˜ ao Preto, S ˜ ao Paulo, Brazil ABSTRACT Background and Aim: There were strong evidences that nitric oxide has capital importance in the progressive vasodilatation associated with varied circulatory shock forms, including systemic inflam- matory response syndrome (SIRS), in patients undergoing cardiac surgeries for cardiopulmonary bypass (CPB). If CPB procedures, per se, are the inciting stimulus for inflammation, plasma nitrate/nitrite (NOx) excretion would be expected to be higher in these patients rather than in patients operated without CPB. In consequence, we hypothesized that increased levels of NOx would be predictive for vasoplegic syndrome. Methods: Thirty patients were assigned to three groups: Group 1—coronary artery bypass graft (CABG) roller pump CPB; Group 2—CABG centrifugal vortex pump CPB; and Group 3—heart valve surgery roller pump CPB. Sampling of venous blood for chemiluminescence plasma NOx dosage was achieved at the following time points: (1) before anesthesia induction; (2) after anesthesia induction; (3) before heparin in- fusion; (4) after heparin infusion; (5) CPB-30 minutes; (6) CPB-60 minutes; (7) before protamine infusion; (8) after protamine infusion; and (9) on return to the recovery area. Results: There were no intergroup differ- ences regarding age and anesthetic regimen, and the number of arteries grafted was not different between the CABG groups. There were no NOx statistic differences, neither among the three groups of patients or among the surgery time. In addition, there was no correlation among NOx, lactate, and hemoglobin. Con- clusions: Considering the inflammatory process intrinsic to CPB, this study reinforces the idea that plasma NOx is not useful as a biomarker of inflammatory response onset, which may or may not lead to SIRS and/or vasoplegic syndrome. doi: 10.1111/j.1540-8191.2008.00649.x (J Card Surg 2008;23:336-338) Surgery involving cardiopulmonary bypass induces an inflammatory response due to the contact of blood with the nonphysiological surface. 1,2 Inflammation may increase the production of nitric oxide, either by in- creasing the activity of constitutive nitric oxide syn- thase (eNOS) or by inducing inflammation-specific sys- tems, that is, inducible nitric oxide synthase (iNOS). 3 If cardiopulmonary bypass (CPB) procedures, per se, are the inciting stimulus for inflammation, plasma ni- trate/nitrite (NOx) excretion would be expected to be higher in those patients operated on CPB. This hypoth- esis led us to look at the chemiluminescence method to measure NOx levels as a biomarker for inflammatory response triggered by CPB plastic components and my- This work is supported in part by FAPESP (Funda¸ c˜ ao de Amparo ` a Pesquisa do Estado de S ˜ ao Paulo, Brasil) and FAEPA (Funda¸ c˜ ao de Apoio ao Ensino, Pesquisa e Assist ˆ encia do Hospital das Cl´ ınicas da Faculdade de Medicina de Ribeir ˜ ao Preto da Universidade de S ˜ ao Paulo). Address for correspondence: Paulo Roberto B. Evora, M.D., Ph.D., Rua Rui Barbosa, 367, Apto. 15, 14015 120 – Ribeirao Preto, Sao Paulo, Brazil. Fax: 55 (16) 3602-2497; e-mail: prbevora@netsite.com.br ocardial injury. In addition, we tried to find correlations between NOx and hemoglobin (NO natural scavenger) and plasma lactate (tissue perfusion biomarker). METHODS Thirty adult patients undergoing elective CPB (2.4 L/min/m 2 ), cooled to 28–32 ◦ C, used the same CPB product (Braile Biomedica, S ˜ ao Jos ´ e do Rio Preto, Brazil). Four senior surgeons performed all proce- dures. All patients received preoperative premedication with 0.05 mg/kg of midazolan, anesthesia induced by sulfentanil (0.5–10 μg/kg/min) and ethomidate (0.2–0.4 mg/kg), and muscle relaxation provided by vecuronium (0.1 mg/kg). In addition, the anesthesia was maintained by isoflurane inhalation. Standard monitoring methods including radial artery line, central venous catheter, two peripheral catheters, and urinary catheter were used in all patients. In low ejections fractions patients, a Swan- Ganz catheter (Edwards Lifesciences, Irvine, CA, USA) was inserted via the right jugular vein after induction of anesthesia.