Telematics in Medicine: A Network Infrastructure to Optimize Processes in Cardiology and Heart Surgery

OBJECTIVES

During the past 2 decades, cardiac surgery has developed into a high-tech field. Increasing numbers of urgent surgical procedures mean that the time interval from diagnosis to surgical treatment must become ever shorter. Optimizing inconvenient and slow processes such as postal correspondence by using internet services is therefore mandatory in current cardiosurgical practice, and this includes the electronic transfer of patient data and diagnostic imaging material [12]. This study focuses on the internet connection of several cardiac referral centers to a cardiosurgical institution.

METHODS

Eleven cath lab centers were connected to a cardiosurgical center by internet. Auser program was especially developed to optimize connecting processes with the department. Data conversion was based on HL7 codes and angiograms were based on CD-ROM mediums and the DICOM standard. An online registration based on the HL7 communications standard was provided.

RESULTS

All cath lab centers were successfully connected to the cardiosurgical institution. Angiography data were transmitted within 30 +/- 15minutes. The time interval from diagnosis to decision for surgery decreased from 36 +/- 13 hours to 1 +/- 0.5 hours (p = 0.01). Urgent or emergent surgery could be provided after 18 +/- 19 hours, compared to 56 +/- 35 hours before (p = 0.02).

CONCLUSION

Special programs transmitting data via the internet significantly reduces the time interval from diagnosis to surgical treatment. Standardizing data transmitting processes from referral centers markedly optimizes cardiological and cardiosurgical treatments and could thereby improve survival rates and reduce costs.

Aminoterminal B-type pro-natriuretic peptide as a marker of recovery after high-risk coronary artery bypass grafting in patients with ischemic heart disease and severe impaired left ventricular function

BACKGROUND

Aminoterminal B-type pro-natriuretic peptide (NT-proBNP) is a reliable indicator of heart failure severity. Levels of NT-proBNP are markedly increased in patients with coronary artery disease (CAD) and severely impaired left ventricular (LV) function. The aim of our study was to assess the impact of NT-proBNP levels after high-risk coronary artery bypass grafting (CABG) with regard to recovery potential.

METHODS

Between 1998 and 2004, 121 patients with CAD and severely impaired LV function, who were undergoing CABG, were investigated. Their mean age was 64 +/- 11 years. All patients were in New York Heart Association (NYHA) Class III/IV status; LV ejection fraction (EF) was 20 +/- 6%. All survivors underwent follow-up (59 +/- 34 months) spiroergometric, electrocardiographic (ECG) and echocardiographic assessment and were tested for routine blood controls and NT-proBNP levels (Roche, Mannheim, Germany).

RESULTS

The survival rate after 8 years was 70%. All survivors received follow-up assessment. Among survivors the median NT-proBNP level at follow-up was 896 (521 to 1,687) pg/ml. The maximum oxygen uptake was 14.6 +/- 4.9 ml/min/kg, and EF increased to 42% at follow-up among all survivors. On dichotomizing survivors into two groups with NT-proBNP levels above and below the median, the post-operative body mass index was significantly higher in the high NT-proBNP group (p = 0.036). EF (p = 0.028) and NYHA classification (p < 0.05) improved significantly in both groups, with a tendency toward higher EF in the low NT-proBNP group.

CONCLUSIONS

Patients undergoing a high-risk CABG procedure have a survival rate comparable to heart transplantation patients and show a potential for clinical and myocardial recovery. NT-proBNP use a useful marker for recovery after a high-risk CABG procedure, with significant correlation with clinical parameters.

Harvest of the radial artery: technique of the skeletonization and pedicle preparation

Nowadays, radial artery grafts play a significant role in coronary artery revascularization, however, harvesting techniques are not standardized. We developed various surgical techniques for radial artery harvesting considering the anatomic landmarks of the foramen, including conventional surgery (with scissors and clips) and procedures with ultrasonic scalpel and retrieving the radial artery graft in a pedicle or in a skeletonized manner.

Cardiothoracic Surgery after Heart and Heart-Lung Transplantation

OBJECTIVE

We sought to examine our management and the outcomes of cardiothoracic procedures after heart and heart lung transplantation.

METHODS

We performed a retrospective review of cardiothoracic surgical procedures carried out between 1990 and 2004 in patients who had previously undergone heart or heart-lung transplantation at our institution.

RESULTS

Twenty-one out of 340 patients (6.2 %) were identified. Cardiothoracic surgery was performed 44.4 +/- 33 months (range 1 - 115 months) after transplantation. Predominant types of surgery were coronary artery bypass grafting due to allograft vasculopathy (n = 5), aortic surgery due to acute dissection (n = 3), biventricular assist device implantation due to acute rejection (n = 1), tricuspid valve repair (n = 1), multiple cardiac surgical procedures including coronary artery bypass grafting, retransplantation, and tricuspid valve replacement (n = 2), explantation of a functionless heterotopic transplanted heart (n = 1). Lung surgery was performed in six patients due to pneumonia (n = 2), primary lung carcinoma (n = 3), lung torsion following heart-lung transplantation (n = 1). All patients underwent either lobectomy or segmental lung resection. Single lung retransplantation (n = 2) after prior heart-lung transplantation due to bronchiolitis obliterans was performed. In one patient a pneumonectomy (n = 1) due to severe chronic rejection of the contralateral lung was performed. Six subsequent deaths after cardiothoracic procedures were recorded after 1, 4, 78, 163, 205, and 730 days, respectively. Causes of death were advanced carcinoma (n = 1), multi-organ failure due to sepsis (n = 2), sudden heart death (n = 2), and advanced heart failure (n = 1). Fifteen out of 21 patients having undergone cardiothoracic procedures (71.4 %) survived the observation period of 56.6 +/- 34 months (range 1 - 114).

CONCLUSIONS

Reasons for cardiothoracic procedures after prior heart or heart-lung transplantation were allograft vasculopathy, aortic dissections years after transplantation, chronic rejection, and either lung infections or malignancies. Surgical repair can be performed with an acceptable operative risk and good long-term survival rates.

Neoplastic Heart Disease - The Muenster Experience With 108 Patients

BACKGROUND

Tumours of the heart are rare. Different histological subtypes are known. The most common tumour entity is benign cardiac myxoma. Malignant heart tumours are less common. Tumours originating in other organs such as the kidney may also affect the heart by tumour progression via the inferior caval vein. A large experience with surgical treatment of different types of heart tumours is presented.

METHODS

Between January 1989 and April 2004, 108 patients with a heart tumour were included in a database. All patients underwent radical surgical resection, except for 2 patients who had malignant lymphoma of the heart.

RESULTS

Histological findings included 78 myxomas (72.2 %), and 6 other benign cardiac tumours in 5.6 % of the patients. Primary malignant heart tumours were seen in 10 (9.2 %) and renal cell carcinoma with cardiac involvement in 6 (5.6 %) patients. Eight patients presented with tumour metastases inside the heart (7.4 %). Mean overall survival was 12.7 years for myxoma patients and 5.6 years for patients with other benign heart tumours. Patients with primary malignant heart tumours survived 5.5 years on average.

CONCLUSIONS

Heart tumours are rare, but usually life-threatening. Radical surgical resection is the therapy of choice and may offer excellent long-term survival, even in cases with malignant heart tumours.

Clinical situations demanding weaning from long-term ventricular assist devices

OBJECTIVE

Ventricular assist devices are increasingly used to treat patients with acute or chronic end-stage heart failure. We report on circumstances, exemplified on four cases, where a surprisingly favorable clinical course of the patients ultimately demanded early explantation of the device, which was not anticipated prior to its implantation.

METHODS

The four patients were provided with implantable (Micromed BeBakey trade mark, Incor trade mark ) and external pneumatically driven (Thoratec trade mark, Excor trade mark ) devices under emergency conditions and were listed for heart transplantation.

RESULTS

All four patients had an unexpected recovery of myocardial pump function. After careful diagnostic evaluation, all device components were completely removed without extracorporeal circulation. No stepwise weaning protocol was employed.

CONCLUSIONS

Weaning patients from ventricular assist devices after recovery of myocardial pump function can become necessary. Diagnostic evaluation and the implementation of a weaning protocol is still a matter of debate, while complete surgical removal of all device components without extracorporeal circulation is possible with a low risk.

ICD implantation -- between necessity and tragedy

We report on a 42-year-old patient with known dilative cardiomyopathy who underwent placement of a multiple transvenous pacemaker and ICD electrodes, and required removal of all leads via median sternotomy, followed by placement of epicardial electrodes. This experience has led us to question the necessity of the current implantation policies for these systems.

First Experience with Rapamycin-Based Immunosuppression to Improve Kidney Function After Heart Transplantation

This study was designed to gain initial experience with rapamycin in thoracic organ transplant recipients with severely compromised kidney function, i.e. to see whether and how kidney function will improve with a rapamycin-based immunosuppressive protocol.

METHODS

Twelve heart transplant patients were included into the study (serum creatinine > 2.5 mg/dL), with an average time after transplantation of more than 4 years. The calcineurin inhibitor (cyclosporine A = 9, tacrolimus = 3) was reduced by 50 %, and rapamycin added to reach a target level of 8 - 12 ng/dL. Azathioprine was halted, corticosteroid treatment remained unchanged.

RESULTS

After implementing the rapamycin-based immunosuppression kidney function improved in all patients within one week. Serum creatinine dropped from 3.1 +/- 0.6 mg/dL to 2.7 +/- 0.5 mg/dL ( p = 0.0004), creatinine clearance increased from 30.4 +/- 11 mL/min to 40.8 +/- 10.5 mL/min ( p = 0.003). This improvement continued until 3 months after the conversion ( p = 0.032). Thereafter, no statistically significant changes were noted up to 6 months posttransplant ( p = 0.41). Serum cyclosporine levels dropped from 180 +/- 40 ng/mL to 132 +/- 46 ng/mL on average ( p = 0.002). Side-effects occurred in 4 patients and were all related to a rapamycin level exceeding 12 ng/mL.

CONCLUSIONS

We conclude that transplant patients with impaired kidney function will have an immediate benefit from partially replacing calcineurin inhibitors by rapamycin.

[Evaluating the first German diagnosis-related groups (G-DRG) in cardiological patients: problems in the correct medical and economic grouping]

About three years ago, the German Government initiated a complete change in the reimbursement system for costs of the in-hospital treatment of patients. A commission of representatives from every component of the German health system decided to adapt the Australian refined Diagnosis Related Groups (AR-DRG system). The AR-DRG system was selected as it would fit best to the German system and because of its high flexibility and preciseness reflecting severity of diseases and treatments. In October 2002, the first German Diagnosis Related Groups (G-DRGs) were calculated from the data of about 116 hospitals. These data now allow first analyses in how far a correct and precise grouping of patients in specific hospital settings is indeed performed and corresponds to the actual costs. Thus, we thoroughly calculated all costs for material and personnel during the in-hospital stay for each patient discharged during the first 4 months of 2002 from our cardiological department. After performing the grouping procedure for each patient, we analyzed in how far inhomogeneous patient distribution in the DRGs occurred and which impact this had on costs and potential reimbursements. Several different problems were identified which should be outlined in this work regarding three G-DRGs: costs of patients who received an implantable cardioverter defibrillator (F01Z) were markedly influenced by multimorbidity and additional expensive interventions which were not reflected by this G-DRG. Use of numerous catheters and expensive drugs represented a major factor for costs in patients with coronary angioplasty in acute myocardial infarction (F10Z) but seemed to be not sufficiently included in the cost weight. A specific area of patient management in our department is high frequency ablation of tachyarrhythmias which is included in other percutaneous interventions (F19Z). Complex procedures such as ablation of ventricular tachycardia or new innovative procedures as ablation of atrial fibrillation were associated with high costs leading to inadequate reimbursement. Furthermore, problems in the associated codes for diseases and procedures became apparent. Opportunities for future optimization such as specific new DRGs, splitting of DRGs, or the impact of changes in reimbursement for high-outliers were discussed.

Mitral valve surgery in patients with poor left ventricular function

BACKGROUND

Mitral valve surgery for the correction of secondary mitral valve regurgitation (MR) in cardiomyopathy is associated with a poor outcome. Numerous studies have identified a severe left ventricular dysfunction as an indicator for a poor prognosis. The aim of the study was to asses the follow-up after mitral valve surgery and severe left ventricular dysfunction.

METHODS

Between 1994 and 2000, 31 patients with mitral regurgitation and a left ventricular ejection fraction of below thirty percent undergoing isolated repair (n = 16) or replacement (n = 15) were investigated. All patients received maximal drug therapy. Twenty-one patients were New York Heart Association (NYHA) class III and 10 were class IV. Follow-up with echocardiography, ECG, and chest x-ray was performed in 87 % of the survivors. The mean duration of follow-up was 39 +/- 16 months.

RESULTS

The mean duration of ICU and hospital stay was 3.6 +/- 2.1 days and 8.1 +/- 5.4 days, respectively. The 1-, 2-, and 5-year survival rates were 91 %, 84 %, and 77 %, respectively. NYHA class improved from 3.3 +/- 0.8 to 2.1 +/- 0.7 at follow-up (p < 0.01). The ejection fraction improved from 23.1 +/- 6.6 % to 36 +/- 6.8 % at follow-up (p < 0.02). Freedom from readmission for heart failure was 85 %, 79 %, and 68 % at 1-, 2-, and 5 years, respectively.

CONCLUSIONS

Mitral valve surgery improves left ventricular function and reduces heart failure severity in patients with MR and cardiomyopathy. High-risk mitral valve surgery may be an alternative to heart transplantation in selected patients.

Prediction of clinical outcome after cardiac surgery: the role of cytokines, endotoxin, and anti-endotoxin core antibodies

Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) can lead to a systemic inflammatory response syndrome with organ failure and increased morbidity and mortality. The mechanisms of these findings are still under discussion. We investigated whether anti-endotoxin core antibodies, endotoxin, and proinflammatory cytokines influence the clinical course after cardiac surgery. Seventy-eight patients undergoing CABG using CPB were investigated. Anti-endotoxin core antibodies, endotoxin, interleukin (IL)-6, IL-8, IL-1beta, and TNF-alpha were measured 24 h preoperatively and up to 72 h postoperatively. Patients with a postoperative mechanical ventilation time below 24 h (n = 65; Group A) were compared to patients with prolonged respirator therapy (>24 h; n = 13; Group B). Preoperative antibody levels were significantly lower in Group B (P < 0.001). In this group, antibody levels remained decreased during the observation period (P < 0.001). Endotoxin significantly increased 30' postoperatively in both groups (P < 0.002). The increase in Group B was 3-fold higher (P< 0.001). IL-8 increased postoperatively in both groups, peaking 3 h after surgery (P < 0.001). In Group B, the IL-8 release was significantly higher than in Group A (P < 0.001). IL-6 significantly increased in both groups, reaching its maximum 24 h postoperatively (P < 0.001). No differences between groups were observed. No significant changes of IL-1beta and TNF-alpha were observed. We conclude that anti-endotoxin core antibodies may be predictive of adverse outcome after cardiac surgery. The imbalance between antibodies and endotoxin results in an exaggerated increase in endotoxin and IL-8 with an impact on clinical outcome.

Coexistence of non-Hodgkin's lymphoma and non-small cell lung carcinoma: diagnosis and treatment

Abstract. In this communication, we will present a very rare case of the coexistence of non-Hodgkin's lymphoma (NHL; low malignant lymphocytic lymphoma of the B-cell type) and a non-small-cell lung carcinoma (NSCLC). A patient with a 15-year history of NHL developed a generalized relapse of the lymphoma with an additional tumor mass in the left lower lobe of the lung. Bronchoscopy showed the evidence of the NHL. Due to non-responding chemotherapy on the lung tumor, the coexistence of a second malignancy was histologically proved in a second bronchoscopy. Resection of the lung tumor with complex lobectomy and lymphadenectomy was performed. After that, chemotherapy with four cycles of carboplatin supplemented with taxol was induced. The patient was discharged from the hospital with a stable remission of both tumor diseases. Restaging after six months showed no evidence of a tumor relapse. This is a very rare case of the coexistence of NHL and NSCLC; we will discuss the difficulty of diagnostic and treatment of both tumor diseases.

Primary pigmented malignant schwannoma in the posterior mediastinum

This paper describes a rare case of primary pigmented malignant schwannoma arising from the sympathetic trunk in the posterior mediastinum. A 30-year-old woman underwent a thoracoscopic tumor extirpation. A primary pigmented malignant schwannoma was diagnosed histologically. The tumor presented fascicles and whorls of pigmented plump spindle cells and positive immunoreactivity to S-100 protein, vimentin, and HMB-45. Postoperative radiotherapy of the mediastinum was performed. Our case demonstrates the successful thoracoscopic resection and postoperative radiation treatment of a malignant schwannoma.

In vitro modelling of tissue using isolated vascular cells on a synthetic collagen matrix as a substitute for heart valves

BACKGROUND

Tissue engineering is a promising approach for obtaining lifetime durability in biological heart valves. Basic questions with respect to the selection of suitable cell populations as well as scaffolds remain unsolved. The purpose of this study was to develop a tissue-like substitute in vitro for replacement of diseased valves in vivo.

METHODS

Smooth-muscle cells (SMCs) were isolated from human and porcine aortic tissue using the 'explant technique' and endothelial cells from collagenase digestion. Seeding and cultivation of isolated cells was performed on a type-I collagen matrix. The scaffold-cell specimen was investigated using light and electron microscopy. Cupromeronic blue and immunoprecipitation were used for ultracytochemical staining.

RESULTS

SMCs were allowed to grow to multilayers and migrate into the collagen network. We found a tissue-like morphology in these samples characterised by several layers of cells, spaces between the cell layers filled with newly formed extracellular matrix components, compartmentalisation of proteoglycans and their association with fibrilar matrix and the cell surface. Endothelium cells covered the SMCs of the scaffold with a histological topography similar to heart valves.

CONCLUSIONS

This is an approach for in vitro modelling of tissue-like substitutes and preparing plane multicellular tissues as substitutes for heart valves. This model may also be used for cell biological investigations of cell-matrix interactions.

The impact of anti-endotoxin core antibodies on endotoxin and cytokine release and ventilation time after cardiac surgery

OBJECTIVES

We hypothesized that a temporary cardiopulmonary bypass (CPB)-induced reduction of endotoxin antibody levels contributes to elevated endotoxin levels and the associated inflammatory consequences, with a significant influence on the postoperative ventilation time period.

BACKGROUND

Cardiac surgery using CPB induces a systemic inflammatory response syndrome with an associated risk of increased postoperative morbidity and mortality.

METHODS

A total of 100 consecutive patients undergoing elective coronary artery bypass graft surgery using CPB were prospectively investigated. Endotoxin core antibodies (immunoglobulin [Ig] M/IgG against lipid A and lipopolysaccharide), endotoxin, interleukin (IL)-1-beta, IL-6, IL-8 and tumor necrosis factor-alpha were measured serially from 24 h preoperatively until 72 h postoperatively.

RESULTS

Eighty-five patients had no complications (group 1), whereas 15 patients required prolonged ventilation (group 2). In both groups, there was a decrease of all antibodies 5 min after CPB onset, compared with baseline values (p < 0.001), an increase of endotoxin and IL-8 peaking at 30 min postoperatively (p < 0.001) and an increase of IL-6 peaking 3 h postoperatively (p < 0.001). In group 2, preoperative antibody levels were lower (p < 0.01)--specifically, the decrease in IgM was significantly stronger and of longer duration (p < 0.002)--and levels of endotoxin (p < 0.001) and IL-8 (p < 0.001) were higher at 30 min postoperatively.

CONCLUSIONS

We conclude that an CPB-associated temporary reduction of anti-endotoxin core antibody levels contributes to elevated endotoxin and IL-8 release. Furthermore, lower levels of IgM anti-endotoxin core antibodies were associated with a greater rise in endotoxin and IL-8, as well as prolonged respirator dependence.

Feasibility and risks of heart surgery in very elderly: analysis of 200 consecutive patients of 80 years and above

A continuing increase in the number of very elderly patients with symptomatic heart disease referred for cardiac surgery has been observed in the past. Since 1990 all patients of 80 years and above have been included in a prospective study. We report on the results of the first 200 consecutive patients (mean age: 82.2+/-2.1 years). Operative procedures ranged from isolated myocardial revascularization and valve replacement to very complex operations. In a majority of patients, the operations had to be performed as urgent or emergency cases because of advanced heart disease. Overall 30 day mortality was 9.5%. More than two thirds of patients needed treatment of perioperative complications. During long-term follow-up, cardiac surgery in octogenarians has proved to be very effective with excellent functional status and quality of life. Because of favorable results elderly patients should not be denied the benefits of cardiac surgery requiring utilization of significant medical resources.

Pyodera gangrenosum after aortic valve replacement

A 68-year-old male patient developed pyoderma gangrenosum after elective aortic valve replacement. Treatment with steroids and clofazimine was initiated, which resulted in rapid cessation of the necrotic process. Due to thoracic instability, stabilization of the sternum was performed followed by surgical debridement and atraumatic wound closure. Postoperatively, immunosuppression with cyclosporine A was added; the patient recovered completely. Pyoderma gangrenosum is a potential life-threatening complication that must be considered in patients with severely impaired wound healing after cardiac operation.

Transplant vasculopathy: a model for coronary artery disease?

Although transplant vasculopathy and native atherosclerosis are clinically and pathologically different entities, the pathogenesis of both diseases exhibits some common mechanisms. Both may be regarded as responses to injury within a broadened concept of the immune system. Alloantigens (e.g. on donor endothelial cells) or autoantigens (e.g. oxydized LDL cholesterol) are presented by antigen presenting cells to the T cells of the body's immune system. With the appropriate costimulatory signal, this signal pattern generates a differentiated T cell, B cell, and inflammatory cell response whereas without the second signal, the immune cells undergo apoptosis. In case of immune cell proliferation and differentiation, a coordinated pattern of cytokine release is initiated. Monocyte-derived macrophages are also involved in this process which culminates in rolling, sticking, and diapedesis through the coronary vascular endothelium and phenotype switch of medial smooth muscle cells mediated by generation of growth-promoting cytokines. Thus, viewed within a broadened paradigm of the immune system's role both disease entities may represent different vignettes of an integrated pathophysiological response to an endothelial injury.

Effect of high dose platelet inhibitor treatment on thromboembolism in Novacor patients

BACKGROUND

Thromboembolism and bleeding are among the most hazardous complications following implantation of long-term left ventricular support systems. This report focuses on the effect of high dose platelet inhibitor treatment in patients with the Novacor system to prevent thromboembolic events.

METHODS

Thirty-eight (out of 58) Novacor patients (43+/-11 years old) were studied in a non-randomized manner. Postimplantation: 20 patients were treated with heparin only (control group), whereas in the other 18 patients aspirin (3x330 mg/day) and dipyridamol (3x75 mg/day) were added to the treatment protocol (aspirin group).

RESULTS

Age, body size, underlying heart disease and support interval were comparable among both groups, however, patients in the aspirin group were much sicker with regard to urgency status, postoperative right heart failure and hematologic disorders. Cerebral thromboembolic complications were lower in the aspirin group (33% of patients, 0.4+/-0.7 events) as compared to the control group (55% (P=0.18), 1.4+/-2.3 events (P=0. 048)). Non-cerebral thromboembolism of surgical relevance was rare. The incidence of bleeding complications was mildly increased in the aspirin group.

CONCLUSION

The addition of high dose platelet inhibitors seems to lower the incidence of thromboembolism in Novacor patients.

Detection of acute phase response and infection. The role of procalcitonin and C-reactive protein

OBJECTIVE

Established parameters, e.g. C-reactive protein (CRP), do not differentiate specifically enough between patients developing an infection and those exhibiting an acute phase response following cardiac surgery. The objective of this prospective study was to investigate if procalcitonin (PCT) is more helpful than CRP.

METHODS

During a 1-year period, seven out of 563 patients (1.2%) developed systemic infections (group A) after cardiac operations with cardiopulmonary bypass (CPB), and additional eight patients (1.4%) had local wound infections requiring surgical therapy (group B). Blood samples for PCT and CRP measurements were taken preoperatively, at the onset of infection (d1), as well as on the third day (d3), fifth day (d5), and seventh day (d7) following diagnosis of infection. Forty-four randomly selected patients undergoing cardiac surgery with CPB without clinical signs of infection, additional intensive care unit (ICU) management or additional antibiotic treatment served as control (group C) to assess the PCT and CRP contribution to acute phase response. PCT and CRP levels were measured preoperatively, on the first (d1), third (d3) and fifth day (d5) after operation.

RESULTS

At the onset of infection, PCT levels (median interquartile range 25%-75%) increased significantly in group A as compared to baseline values (10.86 (3.28-15.13) ng/ml vs. 0.12 (0.08-0.21) ng/ml), and decreased during treatment to still significantly elevated values on d5 (0.56 (0.51-0.85) ng/ml). CRP levels were significantly elevated on all days investigated with no trend towards normalisation (d1: 164.5 (137-223) mg/l) vs. 1.95 (1.1-2.8) mg/l preoperatively, d5: 181.1 (134-189.6) mg/l. In group B, no increase in PCT levels, but a significant increase of CRP from d1 (165.9 (96.6-181.6) mg/l) vs. 3.7 (2-4.3) mg/l preoperatively) until d5 98 (92.8-226.2) mg/l was detected. In group C, postoperative PCT levels increased slightly but significantly in the absence of infection on d1 (0.46 (0.26-0.77) ng/ml vs. 0.13 (0.08-0.19) ng/ml preoperatively), and d3 (0.37 (0.2-0.65) ng/ml and reached baseline on d5 (0.24 (0.11-0.51) ng/ml)). CRP levels were significantly elevated as compared to baseline on all postoperative days investigated (baseline: 1.75 (0.6-2.9) mg/l, d1: 97.5 (74.5-120) mg/l), d3: 114 (83.05-168.5) mg/l, d5: 51.4 (27.4-99.8) mg/l)). PCT showed a significant correlation to CRP in group A (r =0.48, p < 0.001), a weak correlation in group C (r=0.27, p=0.002) and no correlation in group B. Intergroup comparison revealed a significant difference for PCT between all groups (A>C>B) and significantly higher CRP levels in group A vs. C and in group B vs. C. Thus, the pattern high PCT/high CRP appears to indicate a systemic infection, while low PCT/high CRP indicates either acute phase response or local wound problems, but no systemic infection. The cost for PCT measurements was 5.6-fold higher as compared to CRP.

CONCLUSION

Due to the significant differences in the degree of increase, PCT appears to be useful in discriminating between acute phase response following cardiac surgery with CPB or local problems and systemic infections, with additional CRP-measurement increasing the specificity.

Cytokine response to infection in patients with acute myelogenous leukaemia following intensive chemotherapy

Septic shock is the major cause of treatment-related death in patients with acute myelogenous leukaemia (AML) undergoing intensive chemotherapy. Interleukins (IL)-1 beta, -6, -8, and tumour necrosis factor alpha (TNF-alpha) have been implicated as mediators of septic shock, with circulating leucocytes being considered a major source for their release. However, plasma cytokine levels of leucocytopenic patients with evolving sepsis have not been studied. We have prospectively measured plasma cytokines during chemotherapy-induced leucocytopenia (< 1 x 10(9)/l) in 50 patients with AML. Cytokine levels in patients with severe sepsis (n = 5) or septic shock (n = 8) were compared to those measured in 13 matched patients with uncomplicated febrile infections. In evolving septic shock, IL-6, IL-8 and TNF-alpha peaked within 48 h of fever onset at levels reported for non-leucocytopenic patients and distinctively higher than during uncomplicated febrile episodes (P < 0.05). Peak concentrations measured within 48 h after onset of fever were related to fatal outcome. IL-1 beta was detected in less than 5% of all samples. Cytokine concentrations were unrelated to leucocyte counts and markers of neutrophil or monocyte activation (elastase and neopterin levels, respectively). We conclude that cytokine release associated with evolving septic shock in patients with AML does not depend on circulating leucocytes.