Immunological aspects of cardiopulmonary bypass

Coronary artery bypass grafting in patients with malignancy: a single-institute case series of eight patients

Background

The surgical strategy among patients with malignancy and coronary artery disease (CAD) remains controversial. In this study, we present the experiences of coronary artery bypass grafting (CABG) in patients with malignancy and analyzed the treatment outcomes.

Methods

From January 2011 to October 2021, eight patients combined with coronary artery disease and malignancy, six of them with three-vessel disease and two with anterior descending branch lesions on coronary angiography. The age ranged from 54 to 73 years (61.8 ± 7.7years). Four patients underwent CABG and staging for surgical oncology, and 2 patients underwent CABG and surgical oncology simultaneously. Four patients underwent CABG procedure with cardiopulmonary bypass (on-pump CABG), and the other patients underwent the procedure without cardiopulmonary bypass (off-pump CABG). All patients were followed up for 3 to 96 months (40.4 ± 31.5 months) postoperatively.

Results

The mean number of grafts was 2.6 ± 1.1, there was no in-hospital death, postoperative myocardial infarction, and stroke. Among the eight patients, one patient received chemotherapy and radiation before bypass surgery, which occurred postoperatively pulmonary infection, and the rest of 7 patients had no major adverse cardiovascular events during follow-up periods.

Conclusion

Based on the results of the present study, simultaneous or staged CABG and oncologic surgery according to the TNM stage of the tumor and cardiac assessment is an effective treatment for patients with severe CAD combined with malignancy.

Association Between Exogenous Nitric Oxide Given During Cardiopulmonary Bypass and the Incidence of Postoperative Kidney Injury in Children

OBJECTIVE

To compare the incidence and severity of acute kidney injury (AKI) after cardiac surgery with cardiopulmonary bypass and the administration of exogenous nitric oxide in children.

DESIGN

A retrospective cohort study.

SETTING

A single institution, university hospital.

PARTICIPANTS

All children younger than 18 years of age who underwent surgery with cardiopulmonary bypass.

INTERVENTIONS

Medical records of all eligible patients between January 4, 2017, and June 28, 2019, were reviewed. Patients were divided into two groups based on whether they received exogenous nitric oxide.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was a change in serum creatinine level, defined as the difference between the preoperative creatinine and peak postoperative creatinine. The secondary endpoint was the incidence and severity of postoperative AKI. A difference-in-difference method using fixed-effect multiple linear regression was carried out to compare the difference in maximum serum creatinine changes between the control and intervention groups. Five hundred ninety-one patients were included in the analysis: 298 (50.5%) in the control group and 293 (49.5%) in the intervention group. Control and intervention groups did not vary significantly in terms of baseline characteristics except for bypass time. After adjusting for all baseline variables, there was no statistically significant difference in the increase in serum creatinine between the control and the intervention groups (0.01 [95% CI: -0.03, 0.05], p = 0.545).

CONCLUSIONS

This single-center, retrospective, cohort study found no change in the incidence and severity of postoperative AKI after the administration of nitric oxide into the cardiopulmonary bypass circuit in children.

Possibilities of Combined Surgical Treatment of Lung Tumours and Heart Diseases

The purpose of the study was a retrospective evaluation of the outcome of surgical therapy of lung cancer in patients where there was concomitant cardiac disease and who underwent a cardiac operation either because of ischemic heart disease or because of valvular disease. These patients were operated on at various time intervals (two to ten months) after their cardiac operation. Some patients had their lung cancer surgery after the cardiac operation because of the high risk of possible cardiac postoperative complications; in one patient the lung operation preceded the cardiac one.

[Combined surgical intervention treatments for lung cancer and coronary heart disease patients]

背景与目的

临床上肺癌合并严重冠心病患者逐年增多，本文旨在总结同期心肺手术治疗这类患者的临床经验，为临床诊治工作提供参考。

方法

回顾性分析2003年-2012年我科完成18例同期手术的临床资料。男性16例，女性2例，平均年龄66.11岁。临床TNM分期多为Ⅰ期/Ⅱ期病例，心肺功能良好。

结果

本组病例无手术死亡及新发心肌梗塞。病理诊断鳞癌10例，腺癌8例，病理TNM分期Ⅰa期2例，Ⅰb期8例，Ⅱa期3例，Ⅱb期3例，Ⅲa期2例。术后常见并发症为心律失常、肺不张、肺部感染。手术时间、术后引流量、带管时间及输血量腔镜组均较开胸组有明显下降，两组生存率无统计学差异（P=0.187）。

结论

同期手术治疗肺癌合并严重冠心病安全、有效。胸腔镜使用创伤小，效果较确切。

Early to midterm results of cardiac surgery with concomitant pulmonary resection

BACKGROUND

We report our experience of cardiac surgery with concomitant pulmonary resection, based on analysis of the results.

METHODS

Eleven patients (1 woman, 10 men) underwent cardiac surgery simultaneously with pulmonary resection; ten of them through median sternotomy. The cancer pathology consisted of non-small cell carcinoma (n = 10), and benign teratoma (n = 1). All lung lesions were removed using a wedge resection. Cardiac procedures consisted of off-pump coronary artery bypass grafting (n = 4), aortic valve replacement (n = 3), mitral valve plasty (n = 2), total arch replacement (n = 1), and descending aorta replacement (n = 1). Lung wedge resections were performed after induction with protamine sulfate.

RESULTS

The mean follow-up period was 19 ± 11 months (2-34). There was no operative mortality and no major cardiac complications. Three patients underwent a subsequent lobectomy through lateral thoracotomy. There were two postoperative deaths: one was from an unknown cause, 8 months postoperatively and another was from a lung cancer recurrence, 9 months after surgery. There were two local recurrences, 9 months and 14 months, postoperatively. The mean cancer-free period was 17 ± 10 (2-32) months.

CONCLUSION

Rates of operative mortality and morbidity following cardiac surgery with concomitant pulmonary resection were favorable, and early to midterm results were acceptable.

Detrimental effect of cardiopulmonary bypass (CPB) on malignant disease

Patients with coronary artery disease associated with malignancy are a difficult group of patients to treat. The ideal approach to manage them is still controversial. Both problems can be manage by either a combined or staged operation. The use of CPB during revascularization of the myocardium among patients with malignant disease, may have an effect on dissimination of malignant cells. This was observed among two of our patients. We believe that the use of off-pump technique to revascularize the myocardium is a safe approach and can be performed either in combined or staged surgery to resect malignant disease.

Combined off-pump coronary artery bypass surgery and pulmonary resection

BACKGROUND

Combined cardiac surgery and pulmonary resection using cardiopulmonary bypass (CPB) has been described previously. There are a few reports of combined procedures done without using CPB. Off-pump coronary artery bypass grafting (OPCABG) eliminates organ dysfunction and suppression of immune system related to extracorporeal circulation.

METHODS

Six patients underwent combined OPCABG and lung resection during a 4-year period. Follow-up ranging from 9 months to 3 years is available for these patients.

RESULTS

Malignant pathology was the diagnosis in 5 patients and 1 patient was diagnosed with advanced chronic obstructive pulmonary disease. Right upper lobectomy was performed in 3 patients, left upper lobectomy was performed in 1 patient, right upper and middle bilobectomy was performed in 1 patient, and bilateral lung volume reduction was performed in one patient. Prolonged air leak occurred in 1 patient postoperatively and another patient experienced small right-sided residual pleural space that was resolved at 6 weeks follow-up. There were no operative deaths but there were 2 late deaths. Evidence of recurrence for angina or malignancy upon follow-up was not detected.

CONCLUSIONS

A combined procedure is a safe approach in patients diagnosed with concomitant coronary artery and pulmonary disease. Avoidance of CPB may decrease the incidence of postoperative complications.

Lung cancer resection or aortic graft replacement with simultaneous myocardial revascularization without cardiopulmonary bypass

BACKGROUND

The concomitant occurrence of lung cancer or other thoracic problems requiring surgical treatment in patients with significant coronary artery disease is uncommon.

METHODS

Three patients underwent revascularization of the anterior descending artery, without cardiopulmonary bypass, with simultaneous pulmonary lobectomy (two patients) or replacement of an obstructed descending aortic graft (one patient).

RESULTS

Postoperative ventilation time was < 3 h, and no morbidity related to the combined procedure occurred during midterm follow-up.

CONCLUSIONS

This one-stage approach allowed the immediate solution of two intrathoracic comorbidities, reducing expenses and suffering to the patients and minimizing the risk of bleeding or tumor dissemination secondary to extracorporeal circulation-induced coagulopathy and immunosuppression.

Influence of prophylactic use of pentoxifylline on postoperative organ function in elderly cardiac surgery patients

OBJECTIVE

To study the effects of pretreatment with pentoxifylline before cardiac surgery on postoperative organ function in elderly patients (>80 yrs) undergoing cardiac surgery.

DESIGN

Prospective, randomized, placebo-controlled study.

SETTING

Two-day clinical investigation in an intensive care unit of a university-affiliated hospital.

PATIENTS

Forty elderly patients (age >80 yrs) undergoing first-time elective aortocoronary bypass grafting.

INTERVENTIONS

In 20 patients, pentoxifylline (loading bolus of 300 mg followed by a continuous infusion of 1.5 mg.kg-1.hr-1 until the second postoperative day) was given after induction of anesthesia; another 20 patients received saline solution as placebo.

MEASUREMENTS AND MAIN RESULTS

Concentrations of soluble adhesion molecules (soluble E-selectin, soluble vascular cell adhesion molecule-1, and soluble intercellular adhesion molecules) were measured to assess endothelial function. Liver function was evaluated by monoethylglycinexylidide test and by measuring alpha-glutathione S-transferase plasma concentrations. Renal function was assessed by measuring serum creatinine and urine concentrations of alpha-1-microglobulin. Splanchnic perfusion was assessed by monitoring intramucosal pH by using continuous tonometry. All measurements were performed before pentoxifylline infusion (T0), at the end of surgery (T1), 5 hrs after surgery (T2), and at the morning of the first (T3) and second (T4) postoperative day. Postoperative concentrations of all measured soluble adhesion molecules were significantly higher in the nontreated controls than in the pentoxifylline-treated patients. Monoethylglycinexylidide serum concentrations were significantly lower and abnormal (<50 ng/mL) postoperatively only in the untreated control patients. alpha-Glutathione S-transferase increased in both groups with a significantly higher increase in the control group (from 3.2 +/- 1.2 to 24.1 +/- 4.2 ng/mL) than in the pentoxifylline-treated patients (from 3.8 +/- 1.9 to 11.5 +/- 2.1 ng/mL). Serum creatinine was unchanged in both groups, whereas alpha-1-microglobulin increased significantly more in the control group than in the pentoxifylline-treated group. Intramucosal pH remained almost unchanged in the pentoxifylline patients (>7.35) but decreased significantly in the control group (5 hrs after surgery, intramucosal pH 7.29 +/- 0.13).

CONCLUSIONS

Pretreatment of patients aged >80 yrs undergoing cardiac surgery with pentoxifylline attenuated deterioration of endothelial, renal, and liver function as seen in an untreated control group. Splanchnic perfusion also appears to be improved in the pentoxifylline-treated group. Whether pretreatment with pentoxifylline will improve outcome in this patient population remains to be elucidated.

Epithelium-dependent bronchodilatory activity is preserved in pig bronchioles after normothermic cardiopulmonary bypass

Analogous to vascular endothelium, bronchial epithelium modulates bronchomotor activity by releasing epithelium-derived relaxing factors. Cardiopulmonary bypass (CPB) is associated with endothelial dysfunction. We examined whether CPB may be associated with bronchiolar epithelial dysfunction in pigs. Pigs were exposed to normothermic CPB for 1.5 h and then separated from CPB. Lung tissues were biopsied before and 30 min after CPB. For time control, lung tissues were biopsied at baseline and after 2 hr of anesthesia. Bronchioles measuring about 100 microm were dissected, and the epithelium was either left intact or denuded. Each bronchiolar segment was preconstricted with 10 microM 5-hydroxytryptamine and relaxation responses to nitroprusside 10(-9)-10(-4) M, isoproterenol 10(-9)-10(-4) M, or the inhaled anesthetics halothane or isoflurane 0-2.5 minimum alveolar anesthetic concentration were examined in vitro by videomicroscopy. Bronchiolar segments demonstrated concentration-dependent relaxation responses to each of the dilators examined. Epithelial denudation reduced bronchodilation to isoproterenol, isoflurane, and halothane, but not to nitroprusside. Bronchodilation was not significantly affected by CPB. We conclude that, unlike vascular endothelial function, porcine bronchiolar epithelium-modulated bronchomotor activity is not significantly affected by normothermic CPB.

IMPLICATIONS

Normothermic cardiopulmonary bypass does not result in epithelial dysfunction in pigs. Epithelium-dependent and epithelium-independent bronchodilators may be equally effective before and after cardiopulmonary bypass.

Oxygen consumption after cardiopulmonary bypass surgery in children: determinants and implications

OBJECTIVE

We sought to assess oxygen consumption and its determinants in children shortly after undergoing cardiopulmonary bypass operations.

METHODS

Twenty children, aged 2 months to 15 years (median, 3.75 years), undergoing hypothermic cardiopulmonary bypass operations were studied during the first 4 hours after arrival in the intensive care unit. Central and peripheral temperatures were monitored. Oxygen consumption was continuously measured by using respiratory mass spectrometry. Oxygen delivery was calculated from oxygen consumption and arterial and mixed venous oxygen contents, which were sampled every 30 minutes. Oxygen extraction was derived by the ratio of oxygen consumption and oxygen delivery. Arterial blood lactate levels were measured every 30 minutes.

RESULTS

There was a correlation between oxygen consumption and age in patients older than 3 months (r = -0.76). Mean oxygen consumption increased by 14.7% during the study. The increase in oxygen consumption was correlated with the increase in central temperature (r = 0.73). Nine patients had an arterial lactate level above 2 mmol/L on arrival. There were no significant differences in oxygen consumption, oxygen delivery, and oxygen extraction between the group with lactate levels between 2 and 3 mmol/L and the groups with normal lactate levels both on arrival and at 2 hours. One patient with a peak lactate level of 6.8 mmol/L had initially low oxygen delivery (241.3 mL. min(-1). m(-2)).

CONCLUSIONS

During the early hours after a pediatric cardiac operation, the increase in oxygen consumption is mainly attributed to the increase in central temperature. Oxygen consumption is negatively related to age. Mild lactatemia is common and does not appear to reflect oxygen delivery or oxygen consumption or a more complicated recovery.

Perioperative serum levels of tumour-necrosis-factor alpha (TNF-alpha), IL-1 beta, IL-6, IL-10 and soluble IL-2 receptor in patients undergoing cardiac surgery with cardiopulmonary bypass without and with correction for haemodilution

Cardiac surgery with cardiopulmonary bypass (CPB) leads to a systemic inflammatory response with secretion of cytokines. Alterations in the serum concentrations of cytokines have important prognostic significance. Reports on cytokine release during cardiac surgery with CPB have yielded conflicting results. Haemodilution occurs with the onset of CPB resulting in large fluid shifts during the perioperative course of cardiac procedures. In the present study we compare the perioperative course of serum concentrations of TNF-alpha, IL-1beta, IL-6, IL-10 and sIL-2R with and without correction for haemodilution in patients undergoing coronary artery bypass grafting (CABG) surgery. Twenty male patients undergoing elective CABG surgery with CPB and general anaesthesia using a balanced technique with sufentanil, isoflurane and midazolam were enrolled into the study. Serum levels of TNF-alpha, IL-1beta, IL-6, IL-10 and sIL-2R were measured using commercially available ELISA kits. Simultaneous haematocrit values were obtained at all sample times. Statistical analysis was performed by non-parametric analysis of variance and t-tests for data corrected for haemodilution and data that were not corrected for haemodilution. Adjusted significance level was P < 0.01. Intra-operatively, up to the second post-operative day PCV values were significantly decreased compared with preoperative values. Cytokine measurements not corrected for haemodilution were significantly lower than the corrected values. The perioperative haemodilution and decrease in PCV may lead to an underestimation of the cytokine secretion in post-operative patients. We conclude that cytokine measurements were significantly influenced by the perioperative haemodilution and the subsequent decrease in PCV and may in part account for the varying results reported in the literature regarding cytokine release in patients undergoing CABG surgery.

Attenuation of endothelium-dependent dilation of pig pulmonary arterioles after cardiopulmonary bypass is prevented by monoclonal antibody to complement C5a

We examined whether pulmonary endothelial dysfunction associated with cardiopulmonary bypass (CPB) may be mediated by complement C5a in pigs. Pigs were placed on normothermic CPB for 1 h with or without a previous administration of 1.6 mg/kg anti-C5a monoclonal antibody (MAb), then reperfused for 2 h. Pulmonary tissue myeloperoxidase activity was measured. Expression of nitric oxide synthase (NOS) was measured by reverse transcriptase polymerase chain reaction and Western blotting. Pulmonary arterioles approximately 100 microm in diameter were preconstricted with the thromboxane analog U46619 1 microM, and relaxation responses to adenosine diphosphate 10(-9)-10(-4) M, substance P 10(-12)-10(-6) M, and sodium nitroprusside 10(-9)-10(-4) M were examined in vitro by videomicroscopy. Relaxation to the endothelium-dependent dilators adenosine diphosphate and substance P was attenuated after CPB; this attenuation was prevented by the previous administration of MAb. Relaxation to sodium nitroprusside was not affected by CPB. Neutrophil sequestration, as measured by MPO activity, increased after CPB, either with or without MAb. Transcription of NOS was unchanged by CPB, but translation of constitutive NOS was decreased after CPB, and this decrease was prevented by a previous administration of MAb. We conclude that pig pulmonary endothelial dysfunction associated with CPB may be mediated by C5a. The mechanism may involve changes in NOS translation.

IMPLICATIONS

In pigs, pulmonary endothelial dysfunction may occur after cardiopulmonary bypass due to product(s) of complement activation.

Insulin infusion improves neutrophil function in diabetic cardiac surgery patients

Diabetic patients are at increased risk of wound infection after major surgery, but the effect of perioperative glucose control on postoperative wound infection rates after surgery is uncertain. We tested the effect of an insulin infusion on perioperative neutrophil function in diabetic patients scheduled for coronary artery bypass surgery. Participants (n = 26) were randomly allocated to receive either aggressive insulin therapy (AIT) or standard insulin therapy (SIT) during surgery. Blood was drawn for neutrophil testing before surgery, 1 h after the completion of cardiopulmonary bypass, and on the first postoperative day. Neutrophil phagocytic activity decreased to 75% of baseline activity in the AIT group and to 47% of baseline activity in the SIT group (P < 0.05 between groups). No important differences in neutrophil antibody-dependent cell cytotoxicity were found. This study documents a potentially beneficial effect of continuous insulin therapy in diabetic patients who require major surgery.

IMPLICATIONS

A continuous insulin infusion and glucose control during surgery improves white cell function in diabetic patients and may increase resistance to infection after surgery.

A prospective randomized trial of Duraflo II heparin-coated circuits in cardiac reoperations

BACKGROUND

Heparin-coated circuits in cardiopulmonary bypass have been shown to decrease the systemic inflammatory responses associated with cardiopulmonary bypass. Previous clinical studies on low-risk patients who had coronary artery bypass grafting (CABG) and received full-dose systemic heparin did not have clearly improved clinical outcomes. We hypothesized that the beneficial effects of heparin-coated circuits might be seen in patients who had cardiac reoperations.

METHODS

Three hundred fifty patients who had reoperation with CABG only (58%), or with valve operations (42%) were randomly assigned to receive either a heparin-coated (Duraflo II; study group) or uncoated (control group) circuit. Clinical outcomes were compared and the variables were analyzed using the following three groups: entire populations of study group and control group, subgroup of patients who had CABG reoperation only, and a subgroup who had valve reoperation or combined valve and CABG reoperation.

RESULTS

Preoperative variables were the same in both groups. No difference in clinical outcomes could be demonstrated except that the percentage of patients with major bleeding episodes was significantly lower in the study group (1.2% versus 5.4%, p = 0.035). In the subgroup analysis of patients who had valve reoperations, lower blood transfusion requirements in the intensive care unit (p = 0.013) were found in the study group. When the subgroup of patients who had CABG reoperations was analyzed separately, there was a trend toward less reoperation for bleeding in the study group (0% versus 4.0%, p = 0.058).

CONCLUSIONS

We conclude that the use of heparin-coated circuits was safe and imparted protection from reoperations for bleeding and major bleeding episodes. Material-independent blood activation (eg, blood-air interface and cardiotomy suction) blunted the total effect of the heparin-coated surface.

The inflammatory cytokine response after autotransfusion of shed mediastinal blood

BACKGROUND

The inflammatory response in patients undergoing cardiac surgery with cardiopulmonary bypass is well known and increased levels of inflammatory cytokines have been shown. High levels of cytokines have been reported in blood drained from the surgical field. The present study aimed to elucidate whether autotransfusion of shed mediastinal blood in itself causes increased cytokine levels in coronary artery bypass graft (CABG) patients.

METHODS

A prospective, randomized controlled study was performed in 23 patients having elective uncomplicated CABG. Autotransfusion of shed mediastinal blood was done every hour for 18 h in group I. In group II, the shed mediastinal blood was accumulated for 4 h in the cardiotomy reservoir and then autotransfused every hour for the next 14 h. Plasma levels of tumour necrosis factor-alpha (TNFalpha) and interleukin (IL)-1alpha, IL-1beta, IL-6 were measured. In vitro study of cytokine production was performed with or without stimulation (phytohaemagglutinin (PHA) and Escherichia coli (E. coli) lipopolysaccharide (LPS)).

RESULTS

We found high levels of IL-6 in the shed mediastinal blood. However, autotransfusion of shed mediastinal blood did not lead to increased level of cytokines (TNFalpha, IL-1alpha, IL-1beta and IL-6) in plasma in group I nor in group II. In vitro study showed activation of the leucocytes in the shed mediastinal blood with a significantly increased production of TNFalpha and IL-6 both in the stimulated and non-stimulated samples.

CONCLUSION

Shed mediastinal blood contains high levels of IL-6. However, autotransfusion of shed mediastinal does not cause measurable elevations in plasma levels of IL-6. In vitro study shows that autotransfusion activates leucocytes, which may enhance production of inflammatory cytokines.

Opioids in cardiac surgery: cardiopulmonary bypass and inflammatory response

After a brief overview of the history of narcotic use in anesthesia, the various opiates are reviewed mainly from a stress-reducing, antiinflammatory and hemodynamic perspective. The emphasis is placed on cardiac anesthesia.

Effects of anaesthesia based on high versus low doses of opioids on the cytokine and acute-phase protein responses in patients undergoing cardiac surgery

BACKGROUND

Cardiac surgery with cardiopulmonary bypass (CPB) evokes a systemic inflammatory response involving the proinflammatory cytokines tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-1, IL-6, IL-8 and anti-inflammatory cytokines such as IL-10. Like IL-10, opioids downregulate the immune responses in vivo and in vitro, including the activity of the cytokine-producing monocytes and granulocytes. The proinflammatory cytokines are potent inducers of the hepatic acute-phase protein synthesis. The aim of the present study was to investigate if choice of anaesthesia, based on high-dose opioids (fentanyl) versus low-dose opioids influenced the release of IL-6, IL-8, and IL-10. Secondly, it was investigated whether serum amyloid P-component (SAP) is an acute-phase protein in man such as C-reactive protein (CRP), with which it is physically and structurally related.

METHODS

Sixteen patients submitted to elective coronary artery bypass grafting (CABG) surgery were randomized to either low-dose opioid anaesthesia consisting of thoracic epidural analgesia combined with inhalational anaesthesia (group I) or high-dose fentanyl anaesthesia (group II). From each patient 18 blood samples were taken perioperatively. Cytokine analyses were performed with ELISA, CRP and SAP mere measured with rocket immunoelectrophoresis (RIE).

RESULTS

Surgery and CPB elicited a marked, transient and almost simultaneous proinflammatory and anti-inflammatory cytokine response with no differences between the groups. The cytokine levels returned to preoperative levels 1-3 d after operation. Anaesthesia and surgery did not affect SAP plasma levels while patients showed a major increase in CRP concentrations preceding the cytokine responses.

CONCLUSION

CABG performed during two different anaesthetic techniques, high-dose fentanyl versus low-dose opioid anaesthesia, elicited a well-defined cytokine response with minor variation in the time course of each cytokine. The cytokine production was not modified by type of anaesthesia. Finally, SAP is not an acute-phase protein in men.

Neutrophil adhesion molecule expression during cardiopulmonary bypass: a comparative study of roller and centrifugal pumps

The purpose of this study was to determine whether adhesion molecules and markers of cell activation were preferentially increased on blood neutrophils during cardiopulmonary bypass (CPB) and whether such effects were influenced by the use of a roller pump or a centrifugal pump. Forty-six patients undergoing open heart surgery were randomly allocated into either the roller or centrifugal groups. Blood (1 ml volumes) was removed from arterial and venous lines immediately before and 1 h after the start of bypass. Whole blood samples were immunolabelled and flow cytometry used to measure the distribution and expression of the adhesion molecules CD11b, CD18, CD62L on neutrophils, monocytes and lymphocytes, in addition to CD64 on neutrophils and monocytes, and CD14 on monocytes. The expression of CD11b was significantly enhanced on neutrophils in arterial and venous samples from both the roller pump (mean 84% and 100% increase, respectively; p < 0.001) and centrifugal pump (mean 74% and 73% increase, respectively; p < 0.001) groups. Neutrophil L-selectin expression increased to a small but significant extent in arterial and venous samples from the centrifugal pump group (mean 16% increase; p < 0.001) and in venous samples from the roller pump group (mean 10% increase; p < 0.01). Neither the percentage of neutrophils bearing CD11b/CD18, CD62L and CD64, nor the expression of adhesion molecules on lymphocytes and monocytes were modified by 1 h of bypass. These results suggest that patients subjected to CPB with roller or centrifugal pumps are equally at risk to neutrophil activation that could lead to increased interaction of these cells with blood vessel walls.

Heparin coating with aprotinin reduces blood activation during coronary artery operations

BACKGROUND

This study was performed to evaluate whether the combination of heparin-coated extracorporeal circuits (ECC) and aprotinin treatment reduce blood activation during coronary artery operations.

METHODS

Sixty patients were prospectively divided into two groups (heparin-coated ECC and uncoated ECC groups), which were comparable in terms of age, sex, left ventricular function, preoperative aspirin use and consequent intraoperative aprotinin use, number of grafts, duration of aortic cross-clamping, and duration of cardiopulmonary bypass. Blood activation was assessed at different times during cardiopulmonary bypass by determination of complement activation (C3 and C4 activation products C3b/c and C4b/c and terminal complement complex), leukocyte activation (elastase), coagulation (scission peptide fibrinopeptide 1 + 2), and fibrinolysis (D-dimers).

RESULTS

Univariate analysis showed that heparin-coated ECC, under conditions of standard heparinization, did not reduce perioperative blood loss and need for transfusion. Heparin coating, however, reduced maximum values of C3b/c (446 +/- 212 nmol/L versus 632 +/- 264 nmol/L with uncoated ECC; p = 0.0037) and maximum C4b/c values (92 +/- 48 nmol/L versus 172 +/- 148 nmol/L with uncoated ECC; p = 0.0069). Levels of terminal complement complex, elastase, fibrinopeptide 1 + 2, and D-dimers were not significantly modified by the use of heparin-coated ECC. Multivariate analysis showed that the intergroup differences in maximum C3b/c and C4b/c values were more pronounced in women in part with high baseline values of C3b/c. We also found that aprotinin contributed to the reduction of maximum values of fibrinopeptide 1 + 2 and D-dimers, whereas heparin coating had no significant influence on these parameters.

CONCLUSIONS

We found no evidence of combined properties of heparin-coated ECC and aprotinin in reducing complement activation, coagulation, and fibrinolysis. We therefore recommend use of both together to achieve maximal reduction of blood activation during cardiopulmonary bypass for coronary artery operations.

Synergistic immunosuppression caused by high-dose methylprednisolone and cardiopulmonary bypass

BACKGROUND

Steroid use during cardiac operations may reduce the risk of postperfusion lung syndrome, but both cardiopulmonary bypass and steroids are immunosuppressive. The synergistic effects of the bypass and steroids on patients' immunologic activities, hemodynamics, and metabolisms during and after heart operations have not been clarified systematically.

METHODS

Twenty-four patients undergoing valve replacement were studied in a randomized, double-blind trial. Twelve of these patients (S group) received bolus methylprednisolone, 20 mg/kg body weight, and the remaining 12 patients (C group) received a placebo intravenously before and after bypass. Blood cell count, C-reactive protein, lymphocyte surface markers (CD3, CD4, CD8, CD16, and CD20), phytohemagglutinin response, interleukin-2 production, and natural killer cell activity were examined on admission through day 7. Cardiac output, blood gas, electrolyte, lactate, and serum glucose levels were examined perioperatively.

RESULTS

The peak white blood cell count in the S group was higher than that in the C group (analysis of variance: p [group] = 0.0436). The peak C-reactive protein level was higher in the C group than in the S group (p [group] < 0.0001). From the analysis of the surface markers, the steroid increased the natural killer cells before and soon after bypass (p [group] = 0.0117), and later tended to increase the CD4+ T and B cells during the postoperative recovery period. The phytohemagglutinin response in both groups decreased after bypass (p [time] < 0.0001), but the steroid caused exaggerated decreases before (p < 0.01 by Student's t test) and soon after (p < 0.001) bypass in the S group (analysis of variance: p [group] = 0.0127). The interleukin-2 production was suppressed by bypass alone after the bypass in the C group, but was further suppressed by the steroid before and after bypass in the S group (p [group] = 0.0446). The cardiac index, water balance, electrolytes, arterial oxygen tension, and timing of extubation were not different between the groups. In contrast, the glucose (p [group] = 0.0486) and lactate (p [group] = 0.0525) levels were higher in the S group than those in the C group.

CONCLUSIONS

T-cell functions are synergistically suppressed by cardiopulmonary bypass and high-dose methylprednisolone in heart operations. The hemodynamic benefits of the steroid are negligible, whereas glucose tolerance is worsened by the steroid during bypass.

Endothelial cell injury in cardiovascular surgery: the systemic inflammatory response

Many of the components currently used to perform cardiovascular operations lead to systemic insults that result from cardiopulmonary bypass circuit-induced contact activation, circulatory shock, and resuscitation, and a syndrome similar to endotoxemia. Experimental observations have demonstrated that these events have profound effects on activating endothelial cells to recruit neutrophils from the circulation. Once adherent to the endothelium, neutrophils release cytotoxic proteases and oxygen-derived free radicals, which are responsible for much of the end-organ damage seen after cardiovascular operations. Recently the cellular and molecular mechanisms of endothelial cell activation have become increasingly understood. It is conceivable that once the molecular mechanisms of endothelial cell activation are better defined, therapies will be developed allowing the selective or collective inhibition of vascular endothelial activation during the perioperative period.

An investigation of the effects of heparin, low molecular weight heparin, protamine, and fentanyl on the balance of pro- and anti-inflammatory cytokines in in-vitro monocyte cultures

We report a study conducted to determine if drugs given peri-operatively during cardiac surgery could themselves modulate the balance of pro- and anti-inflammatory cytokines. We determined the cytokine response of 10 separate in vitro monocyte cultures to the administration of drugs at concentrations used during cardiac 'surgery:fentanyl (25 ng.ml-1), heparin 2.5 i.u.ml-1, heparin with an equal concentration of protamine, and enoxaparin 2.5 i.u.ml-1. Fentanyl, heparin and low molecular weight heparin (enoxaparin) led to increased tumour necrosis factor alpha but this did not reach statistical significance. Tumour necrosis factor soluble receptor 1 and 2 was not elevated. Interleukin-1 beta was increased by heparin (p < 0.05), whereas interleukin-1 receptor antagonist was increased by fentanyl (p < 0.05). Protamine blocked the heparin-induced increase in tumour necrosis factor alpha and interleukin-1 beta. These data raise the possibility that endogenous and exogenously administered opioids may be partly contributing to the interleukin-1 receptor antagonist response seen during major surgery.

Heparin-coated circuits and aprotinin prime for coronary artery bypass grafting

BACKGROUND

The biocompatibility of an extracorporeal circuit is improved by heparin bonding onto its inner surface. To determine the effect of heparin-coated circuits for cardiopulmonary bypass with aprotinin prime on postoperative recovery and resource utilization, a prospective study was done in 102 patients undergoing coronary artery bypass grafting with full systemic heparinization.

METHODS

Patients were randomly allocated to be treated with either a heparin-coated circuit (n = 51) or an uncoated circuit (n = 51). Differences in blood loss, need for blood transfusion, morbidity, and intensive care stay were analyzed.

RESULTS

No differences in blood loss and need for blood transfusion were found between the groups. The relative risk for adverse events in the heparin-coated group was 0.29 (95% confidence interval ranging from 0.10 to 0.80). Adverse events included myocardial infarction (2 patients in the uncoated group versus 0 in the heparin-coated group), rethoracotomy for excessive bleeding (1 versus 2), rhythm disturbance (7 versus 2), respiratory insufficiency (4 versus 0), and neurologic dysfunction (2 versus 0). The lower incidence of adverse events in the heparin-coated group was associated with a shorter intensive care stay (median, 2 days; range, 2 to 5 days) compared with the uncoated group (median, 3 days; range, 2 to 19 days, p = 0.03). The cost savings of 1 day of intensive care stay counterbalanced the additional costs of heparin-coated circuits.

CONCLUSIONS

The use of heparin-coated circuits for cardiopulmonary bypass with aprotinin prime resulted in a significant reduction in mobidity in the early postoperative phase and a concomitant decrease in intensive care stay, resulting in important cost savings.

The role of cytokines in cardiac surgery

Cytokines are a large and rapidly expanding group of polypeptides produced by many different cell types. Increasing interest has been focused on the role of cytokines as mediators of metabolic, immunological and endocrine responses to surgery. The cytokine response in patients undergoing cardiac surgery during cardiopulmonary bypass (CPB) is fairly well-defined and dominated by the proinflammatory cytokines IL-6, TNF alpha and IL-8 and the antiinflammatory cytokine IL-10. Little is known about the cytokine response in patients who develop postoperative complications but CPB with mechanical trauma and blood contact to artificial membranes is definitely an unphysiological state and may contribute to an uncontrollable response similar to that of patients with multiorgan failure and septic shock.

Increased oxygen consumption after cardiac surgery is associated with the inflammatory response to endotoxemia

OBJECTIVE

The aim of this study was to determine whether the increase in post-operative oxygen consumption (delta VO2) in cardiac surgery patients is related to endotoxemia and subsequent cytokine release and whether delta VO2 can be used as a parameter of post-perfusion syndrome.

DESIGN

Prospective study.

SETTING

Operating room and intensive care unit of a university hospital.

PATIENTS

Twenty-one consecutive male patients undergoing elective coronary artery bypass surgery without major organ dysfunction and not receiving corticosteroids.

MEASUREMENTS AND RESULTS

Plasma levels of endotoxin, tumor necrosis factor (TNF) and interleukin-6 (IL-6) were measured before, during and for 18 h after cardiac surgery. Oxygen consumption, haemodynamics, the use of IV fluids and dopamine, body temperature and the time of extubation were also measured. Measurements from patients with high delta VO2 (> or = median value of the entire group) were compared with measurements from patients with low delta VO2 (< median). Patients with high delta VO2 had higher levels of circulating endotoxin (P = 0.004), TNF (P = 0.04) and IL-6 (P = 0.009) received more IV fluids and dopamine while in the ICU, and were extubated later than patients with low delta VO2. Several hours after delta VO2 the patient's body temperature rose. Forward stepwise regression analysis showed that circulating endotoxin and TNF explained 50% of the variability of delta VO2.

CONCLUSIONS

This study demonstrates that patients with high post operative oxygen consumption after elective cardiac surgery have higher circulating levels of endotoxin, TNF and IL-6 and also have more symptoms of post-perfusion syndrome. Early detection of high VO2 might be used as a clinical signal to improve circulation in order to meet the high oxygen demand of inflammation. In addition, continuous measurement of VO2 provides us with a clinical parameter of inflammation in interventional studies aiming at a reduction of endotoxemia or circulating cytokines.

RETRACTED: Hypothermic versus normothermic cardiopulmonary bypass: influence on circulating adhesion molecules

OBJECTIVE

Cardiopulmonary bypass (CPB) may result in a whole-body inflammatory response with the risk of subsequent development of organ failure. Leukocyte-endothelial binding followed by neutrophil migration appear to play a central role. This process is markedly influenced by adhesion molecules. Whether plasma levels of circulating adhesion molecules are beneficially influenced by hypothermic CPB was studied in patients undergoing either hypothermic or normothermic CPB.

DESIGN

Prospective, randomized study.

SETTING

Single-Institutional, clinical investigation in a cardiac anesthesia department of a university hospital.

PARTICIPANTS

30 patients scheduled for elective aortocoronary artery bypass grafting.

INTERVENTIONS

The patients were prospectively and randomly divided into two groups: group 1 underwent hypothermic CPB (rectal temperature 27 to 28 degrees C; n = 15) and group 2 normothermic CPB (rectal temperature > 36 degrees C; n = 15).

MEASUREMENTS AND MAIN RESULTS

Plasma levels of circulating (soluble) adhesion molecules (endothelial leukocyte adhesion molecules [sELAM-1], vascular cell adhesion molecule-1 [sVCAM-1], intercellular adhesion molecule-1 [sICAM-1], and granule membrane protein 140 [sGMP-140]) were measured from arterial blood samples using enzyme-linked immunosorbent assays (ELISA) after induction of anesthesia (= baseline values), after weaning from bypass, at the end of surgery, 5 hours after the end of CPB, and on the morning of the first postoperative day. Mean rectal temperature of group 1 was 27.2 +/- 0.4 degrees C and 36.7 +/- 0.4 degrees C in group 2. In both groups, plasma levels of sELAM-1 were significantly higher than baseline only 5 hours after CPB. sICAM-1 increased until the first postoperative day (group 1: +35%; group 2: +37%) without, however, exceeding the normal range. sVCAM-1 plasma levels increased after CPB (group 1: +56%; group 2: +40%). At the end of surgery and 5 hours after CPB, sGMP-140 plasma levels were significantly higher in the hypothermic (increase from 301 +/- 34 to 582 +/- 57 ng/mL) than in the normothermic patients (increase from 310 +/- 45 to 480 +/- 32 ng/mL). On the first postoperative day, both groups showed similar, significantly elevated plasma levels of sGMP-140.

CONCLUSIONS

Plasma levels of circulating adhesion molecules sELAM-1, sICAM-1, and sVCAM-1 did not differ between hypothermic and normothermic CPB, indicating no differences in endothelial activation between the two groups. Only sGMP-140 plasma levels were increased more after hypothermic CPB. Additional influences of hypothermia on the coagulation system might have contributed to the higher sGMP-140 plasma levels of these patients. The definite role of circulating adhesion molecules in cardiac surgery patients remains to be elucidated.

Human cytokine responses to cardiac transplantation and coronary artery bypass grafting

Cardiac surgery with cardiopulmonary bypass triggers an inflammatory response involving proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin-6, and interleukin-8. To elucidate the pathophysiology of this cytokine response, we explored the possible differences in cytokine responses between patients undergoing heart transplantation and those undergoing coronary artery bypass grafting. Plasma levels of tumor necrosis factor-alpha, interleukin-6, interleukin-8, and interleukin-10 were measured in eight patients undergoing heart transplantation (mean age 44 years) and eight patients undergoing coronary artery bypass grafting (mean age 61 years). Duration of cardiopulmonary bypass and ischemic time were both longer in the heart transplantation group than in the coronary artery bypass grafting group (133 +/- 26 min vs 100 +/- 31 min, p < 0.05, and 130 +/- 47 min vs 58 +/- 21 min, p < 0.005, respectively). Samples were collected before heparin administration, at aortic crossclamping and declamping, and at 0.5, 1, 1.5, 2, 4, 12, and 24 hours after declamping. Tumor necrosis factor-alpha levels were significantly higher 30 minutes after aortic declamping in the heart transplantation group than in the coronary artery bypass grafting group (68 +/- 30 vs 18 +/- 5 pg/ml, p < 0.05). Interleukin-6 and interleukin-8 levels were also significantly higher 90 minutes after declamping in patients undergoing heart transplantation than in those undergoing coronary artery bypass grafting (310 +/- 63 vs 169 +/- 24 pg/ml, p < 0.05, and 73 +/- 17 vs 24 +/- 5 pg/ml, p < 0.01, respectively). Furthermore, interleukin-6 and interleukin-8 values 90 minutes after declamping were significantly correlated with the ischemic time (r = 0.72 and r = 0.82, respectively, both p < 0.05). Interleukin-10 levels in both groups rose to reach a peak value of around 115 pg/ml 1 hour after declamping. Patients undergoing heart transplantation exhibited a second peak of tumor necrosis factor-alpha, interleukin-8, and interleukin-10 levels 12 hours after declamping, probably related to the administration of rabbit antihuman thymocyte immunoglobulin (Thymoglobuline) 3 hours after declamping. Interleukin-6 levels decreased more significantly 12 and 24 hours after declamping in patients undergoing heart transplantation, probably related to methylprednisolone therapy. In conclusion, cardiopulmonary bypass is associated with the production of both proinflammatory and antiinflammatory cytokines. The production of proinflammatory cytokines in patients undergoing heart transplantation is higher than that in patients undergoing coronary artery bypass grafting, and this increase could be related to the longer duration of ischemia in the former group. The later course of cytokine levels after heart transplantation may be further influenced by immunosuppressive therapy.

Laboratory studies of the effect of Pall extracorporeal leucocyte filters LG6 and AV6 on patients undergoing coronary bypass grafts

A total of 14 patients with ischaemic heart disease undergoing coronary artery bypass grafts were studied for the effect of AV6 control filter and LG6 neutrophil filter, used in the extracorporeal circulation, on different laboratory parameters. There was no statistical difference between the effects of AV6 and LG6 filters on total white cells, neutrophils, monocytes, lymphocytes, platelets or haemoglobin. The expression of neutrophil activation antigens identified with a panel of monoclonal antibodies demonstrated that for the LG6 filter the leucocyte tyrosine phosphate CD45Ro fell during the procedure, whilst there were no significant changes in any of the other neutrophil antigens. The AV6 filter did not significantly diminish the expression of any of the neutrophil antigens. An indirect measure of superoxide production using Dihydrorhodamine 123 identified that the more activated cells appeared to be depleted across the LG6 filter which was not evident with the AV6 filter. These studies indicate that the LG6 is not capable of significantly depleting the neutrophil load generated during extracorporeal circulation but may be capable of selectively removing the more activated forms.

Effects of a paf-receptor antagonist on hemodynamics during and after cardiopulmonary bypass

OBJECTIVES

To assess after cardiopulmonary bypass (CPB) the role of paf-acether (paf), a phospholipid mediator whose injection in animal mimics the hemodynamics observed after CPB.

DESIGN

Prospective double-blind randomized study.

SETTING

Single institutional university hospital.

PARTICIPANTS

18 patients scheduled to undergo coronary artery bypass graft.

INTERVENTIONS

18 patients randomly received a placebo (n = 8) or 120 mg BN52021 (n = 10), a paf-receptor antagonist injected twice just before vascular cannulation and before cross-clamp release.

MEASUREMENTS AND MAIN RESULTS

Hemodynamic measurements were performed with a pulmonary artery and a radial artery catheter before and after the first injection of BN52021 or placebo, at the end of CPB, 1, 15, and 30 minutes after protamine infusion, then 6 hours and 24 hours postoperatively. BN52021 infusion, did not affect hemodynamic parameters. After CPB, the pulmonary artery pressures, the cardiac index, and the pulmonary artery occlusion pressures were statistically the same between groups. By contrast, the pulmonary vascular resistances (1.5 +/- 0.5 IU v 4.5 +/- 0.6 IU, p < 0.05), the right ventricular systolic work index (5.3 +/- 0.91 g m m-2 v 9.37 +/- 1.02 g m m-2, p < 0.05) and the transpulmonary gradient (4.7 +/- 1.1 mmHg v 12.0 +/- 1.2 mmHg, p < 0.05) were lower in the BN52021 group as compared with the placebo group. After protamine infusion, these differences between groups disappeared.

CONCLUSION

Because the inotropic and vasodilator therapy and the volume loading were the same between groups, this study suggests that pretreatment with a paf-receptor antagonist improves post-CPB pulmonary resistance. Nevertheless, this beneficial effect is transient without consequences on left ventricular function indices.

Circulating adhesion molecules in pediatric cardiac surgery

Cardiopulmonary bypass (CPB) may be associated with the risk of a "whole body inflammation." Adhesion molecules, such as endothelial leukocyte adhesion molecule (ELAM-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1), seem to play a pivotal role in the inflammatory response. Soluble forms of these adhesion molecules may serve as markers of endothelial activation or damage. To elucidate whether plasma levels of soluble adhesion molecules differ between pediatric and adult cardiac surgery patients, 15 consecutive children younger than 5 yr undergoing CPB were prospectively studied and compared with adults scheduled for elective coronary artery bypass grafting and valve replacement. Plasma levels of circulating (soluble) adhesion molecules (sELAM-1, sICAM-1, sVCAM-1) were measured from arterial blood samples using enzyme-linked immunosorbent assays after induction of anesthesia (= "baseline"), during CPB, at the end of surgery, and on postoperative days 1 and 2. At baseline, plasma levels of all three soluble adhesion molecules were significantly higher in children than in adults. sELAM-1 and sICAM-1 plasma concentrations were even beyond normal in the children (sELAM-1: 88.8 +/- 13.8 ng/mL; sICAM-1: 349 +/- 27 ng/mL). During CPB and until the end of surgery, plasma levels of all adhesion molecules decreased in the children and remained almost unchanged in the adults. In the children, sELAM-1 remained lower than baseline values until the second postoperative day (45.2 +/- 12.2 ng/mL), whereas sICAM-1 increased in the postbypass period without, however, reaching baseline values (254 +/- 40 ng/mL).(ABSTRACT TRUNCATED AT 250 WORDS)

Leukocyte activation by isolated hyperthermic liver and limb perfusion due to malignancy

Fourteen patients with liver tumor malignancy and sixteen patients with malignant melanoma localized to one limb were studied regarding leukocyte activation with the release of polymorphonuclear neutrophilic (PMN) elastase and of neopterin and formation of cytokines (TNF-alpha and IL-6) during the surgical treatment. Patients undergoing liver resection (n = 10), abdominal hysterectomy (n = 10), or hip replacement surgery (n = 10) served as control groups. Isolated hyperthermic liver perfusion was performed with cytostatic-containing perfusate (melphalan and cisplatinum). Patients with recurrent malignant melanoma confined to one limb underwent isolated hyperthermic limb perfusion with cytostatic-containing perfusate (melphalan). Blood samples for determination of PMN elastase, neopterin, TNF-alpha, and IL-6 were drawn from the patients preoperatively, 1 minute before the start of the perfusion, 60 and 120 minutes after the start of the perfusion, and 24 hours postoperatively. Samples from the perfusate were drawn 60 minutes after the start of the perfusion. High concentration of plasma PMN elastase were found in both patients undergoing liver and limb perfusion and in patients undergoing liver resection surgery. Elevated concentrations of IL-6 were found in the patients undergoing liver perfusion and in patients undergoing liver resection. In none of the patients were there increased concentrations of neopterin or TNF-alpha. The perfusate contained high concentrations of PMN elastase, neopterin, and IL-6. This study also demonstrated that major surgery leads to elevated concentrations of PMN elastase and IL-6. An increase of PMN elastase and IL-6 was seen in response to perfusion and to surgical trauma.

Comparison of the effects of centrifugal versus roller pump on the immune response in open-heart surgery

We compared the effects of a centrifugal pump with those of a roller pump on immune responses in 26 coronary artery bypass surgery patients during cardiopulmonary bypass (CPB). The patients were randomly allocated into a (Biomedicus) centrifugal pump group and a (Stöckert) twin roller pump group. Leucocyte and differential counts; percentages of lymphocyte subpopulations (CD3-, CD4-, CD8-, CD16-, CD20- and CD25-positive lymphocytes) and monocytes (CD14); phytohaemagglutinin-, concanavalin A-, and pokeweed mitogen-induced and unstimulated proliferation of separated lymphocytes; unstimulated and pokeweed mitogen-stimulated production of IgG, IgM, or IgA; and plasma fibronectin, C-reactive protein and serum albumin concentrations were measured preoperatively, immediately before CPB, immediately before aortic declamping and on the first postoperative morning. Significant changes were seen in these variables, but no differences occurred between the groups.

Endotoxemia, complement, and white blood cell activation in cardiac surgery: a randomized trial of laxatives and pulsatile perfusion

Endotoxin activates complement and white blood cells and all are implicated in the pathologic effects of cardiopulmonary bypass (CPB). We investigated if reduction in intestinal bacterial load with a laxative and/or pulsatile perfusion to improve bowel circulation during CPB reduced endotoxemia and complement and white blood cell activation. Sixty patients were randomized to four groups in a 2 x 2 factorial structure: group 1 (no laxative, nonpulsatile perfusion); group 2 (laxative, nonpulsatile perfusion); group 3 (no laxative, pulsatile perfusion); and group 4 (laxative, pulsatile perfusion). Plasma concentrations of endotoxin, C3a and C5a, and granulocyte elastase (GE) were measured before anesthesia, skin incision, and heparin administration; during CPB (1, 30, 60, 90, and 120 minutes and after protamine administration); and after CPB at 3, 6, 12, 24, and 48 hours and 7 days. In all groups there was a small increase in the concentration of endotoxin (overall from 6 ng/L before CPB to 11 ng/L at 90 to 120 minutes; p < 0.001) and significant increases in C3a, C5a, and GE levels but no significant differences among the groups. Endotoxin levels did not correlate with activation of complement or white blood cells. There was a weak correlation between duration of CPB and levels of C3a (r = 0.14; p < 0.03) and GE (r = 0.25; p = 0.001) but not endotoxin or C5a. There was a general correlation between levels of C3a and GE but not in individual patients. In conclusion, CPB results in statistically significant increases in endotoxin, C3a, C5a, and GE during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Perioperative measurements of interleukin-6 and alpha-melanocyte-stimulating hormone in cardiac transplant patients

Interleukin-6 (IL-6) and alpha-melanocyte-stimulating hormone (alpha MSH) are important modulators of the immunologic response to tissue injury and antigenic challenge. Serial changes in the plasma concentrations of these two peptides were measured in 12 patients undergoing heart transplantation. Tissue concentrations of IL-6 in atrial samples from both donor and recipient hearts were also compared. Plasma IL-6 concentration remained stable prior to cardiopulmonary bypass (CPB), initially decreased with the onset of CPB, and then increased significantly over control values at the end of CPB (180 +/- 40 v 53 +/- 60 pg/mL). Plasma IL-6 remained elevated for at least 60 minutes after CPB, and then it returned to control values by 24 hours postoperatively (67 +/- 9 pg/mL). Examination of IL-6 changes after CPB in 10 additional patients undergoing nontransplant cardiac surgery with CPB revealed a similar elevation in IL-6 at 60 minutes after CPB (290 +/- 76 pg/mL). However, IL-6 in the nontransplant group remained significantly elevated at 24 hours (138 +/- 42 pg/mL). These combined results suggest that CPB causes a marked increase in IL-6, and that implantation of a new heart in transplant patients does not augment this increase. The return of IL-6 to control values by 24 hours in the patients who have had transplants suggests that immunosuppression has an appreciable effect on IL-6 at this time. In contrast to IL-6, plasma alpha MSH never increased above control values.(ABSTRACT TRUNCATED AT 250 WORDS)