Peter Feindt

Prophylactic Nasal Continuous Positive Airway Pressure Following Cardiac Surgery Protects From Postoperative Pulmonary Complications: A Prospective, Randomized, Controlled Trial in 500 Patients

BACKGROUND Continuous positive airway pressure is a noninvasive respiratory support technique that may prevent pulmonary complications following cardiac surgery. This study was conducted to determine the efficacy of prophylactic nasal continuous positive airway pressure (nCPAP) compared with standard treatment. The primary end points were pulmonary adverse effects defined as hypoxemia (Pao(2)/fraction of inspired oxygen [Fio(2)] <100), pneumonia, and reintubation. The secondary end point was the readmission rate to the ICU or intermediate care unit (IMCU). METHODS We prospectively randomized 500 patients scheduled for elective cardiac surgery. Following extubation either in the operating room (early) or in the ICU (late), patients were allocated to standard treatment (control) including 10 min of intermittent nCPAP at 10 cm H(2)O every 4 h or prophylactic nCPAP (study) at an airway pressure of 10 cm H(2)O for at least 6 h. RESULTS Prophylactic nCPAP significantly improved arterial oxygenation (Pao(2)/Fio(2)) without altering heart rate and mean arterial BP. Pulmonary complications including hypoxemia (defined as Pao(2)/Fio(2) <100), pneumonia, and reintubation rate were reduced in study patients compared to controls (12 of 232 patients vs 25 of 236 patients, respectively; p = 0.03). The readmission rate to the ICU or IMCU was significantly lower in nCPAP-treated patients (7 of 232 patients vs 14 of 236 patients, respectively; p = 0.03). CONCLUSIONS The long-term administration of prophylactic nCPAP following cardiac surgery improved arterial oxygenation, reduced the incidence of pulmonary complications including pneumonia and reintubation rate, and reduced readmission rate to the ICU or IMCU. Thus noninvasive respiratory support with nCPAP is a useful tool to reduce pulmonary morbidity following elective cardiac surgery.

Impact of preconditioning protocol on anesthetic-induced cardioprotection in patients having coronary artery bypass surgery

OBJECTIVE Anesthetic preconditioning may contribute to the cardioprotective effects of sevoflurane in patients having coronary artery bypass surgery. We investigated whether 2 different sevoflurane administration protocols can induce preconditioning in patients having coronary artery bypass. METHODS Thirty patients were randomly allocated to 1 of 3 groups. All patients received a total intravenous anesthesia with sufentanil (0.3 microg(-1) x kg x h(-1)) and propofol as target controlled infusion (2.5 microg/mL). The control group had no further intervention; 10 minutes prior to establishing the extracorporeal circulation, patients of the sevoflurane-I group received 1 minimum alveolar concentration of sevoflurane for 5 minutes. Patients of the sevoflurane-II group received (2 times) 5 minutes of sevoflurane, interspersed by 5-minute washout 10 minutes prior to extracorporeal circulation. Troponin I was measured as marker of cardiac cellular damage. RESULTS Peak levels of troponin I release were observed at 4 hours after cardiopulmonary bypass and were not affected by 1 cycle of sevoflurane administration (controls: 14 +/- 3 ng/mL vs sevoflurane-I group, 14 +/- 3 ng/mL). Two periods of sevoflurane preconditioning significantly reduced cellular damage compared with controls (peak troponin I level sevoflurane-II group, 7 +/- 2 ng/mL). CONCLUSION These data show that sevoflurane-induced preconditioning is reproducible in patients having coronary artery bypass but depends on the preconditioning protocol used.

Procalcitonin (PCT) in cardiac surgery: diagnostic value in systemic inflammatory response syndrome (SIRS), sepsis and after heart transplantation (HTX).

PURPOSE Since it is of great importance to distinguish between a systemic inflammatory response syndrome (SIRS) and an infection caused by microbes especially after heart transplantation (HTX), we examined patients following heart surgery by determining procalcitonin (PCT), because PCT is said to be secreted only in patients with microbial infections. METHODS Sixty patients undergoing coronary artery bypass grafting (CABG) and 14 patients after heart transplantation were included in this prospective study. In the CABG group we had 30 patients without any postoperative complications (group A). Furthermore we took samples of 30 patients who suffered postoperatively from a sepsis (group B, n=15) or a systemic inflammatory response syndrome (C, n=15). In addition we measured the PCT-levels in 65 blood samples of 14 patients after heart transplantation (Group I: rejection > IIa, II: viral infection (CMV), III: bacterial/fungal infection, IV: controls). RESULTS In all patients of group A the pre- and intraoperative PCT-values and the measurement at arrival on intensive care unit (ICU) were less than 0.2 ng/ml. On the second postoperative day the PCT-value was 0.33+/-0.15 ng/ml in the control group. At the same time it was 19.6+/-6.2 ng/ml in sepsis and 0.7+/-0.4 ng/ml in systemic inflammatory response syndrome patients (P<0.05). In transplanted patients we could find the following PCT-values: Gr.I: 0.18+/-0.06 II: 0.30+/-0.09 III: 1.63+/-1.16 IV: 0.21+/-0.09 ng/ml (P<0.05 comparing group III with I, II and IV). CONCLUSIONS These results show that extracorporeal circulation (ECC) and systemic inflammatory response syndrome do not initiate a PCT-secretion. Septic conditions cause a significant increase of PCT. In addition, PCT is a reliable indicator concerning the essential differentiation of bacterial or fungal--not viral--infection and rejection after heart transplantation.

Predictors and outcome of ICU readmission after cardiac surgery.

OBJECTIVE Readmission to the intensive care unit (ICU) after cardiac surgery is associated with higher costs and may be correlated with an increased mortality. We wanted to evaluate predictors of ICU readmission and to analyze the outcome of those patients. METHODS 3523 patients who underwent CABG and/or valve surgery between 2004 and 2007 were reviewed retrospectively. The reasons for readmission and the postoperative course were analyzed. Furthermore, perioperative risk factors for readmission were determined by multivariate regression analysis. RESULTS Of the 3374 patients discharged from the ICU, 5.9 % (198) of patients required a second stay in the intensive care (group r). The readmission rate was 4.8 % following CABG and 8.9 % following valve +/- CABG ( P < 0.05). The mean interval from ICU discharge to readmission was 3.3 +/- 6.2 days. Of the patients who were not readmitted, 1.3 % died in hospital, compared to 14.4 % in group r ( P < 0.05). After readmission, the mean length of stay in the ICU and in hospital was 7.1 +/- 5.9 and 21.3 +/- 11.1 days (3.1 +/- 1.2 and 13.1 +/- 5.1 days for all other patients [ P < 0.05]). Main reasons for readmission were respiratory failure (59 %), cardiovascular instability (25 %), renal failure (6.5 %), cardiac tamponade/bleeding (6 %), gastrointestinal complications (2 %) and sepsis (1.5 %). Multivariate logistic regression analysis revealed that preoperative renal failure, mechanical ventilation > 24 h, reexploration for bleeding and low cardiac output state were independent predictors for readmission. CONCLUSIONS Patients after valve/combined surgery are more likely to require readmission to the ICU. Respiratory complications were the most common reasons for readmission. To reduce the readmission rate, it is necessary to treat cardio-respiratory problems early, particularly in patients showing predictive risk factors.

Increased preoperative C-reactive protein (CRP)-values without signs of an infection and complicated course after cardiopulmonary bypass (CPB) – operations

OBJECTIVE C-Reactive protein (CRP) is known to be a sensitive indicator of infection. Since it is also involved in the acute phase reaction, it is of great interest, whether an isolated preoperative increase of CRP without further signs of infection is of any prognostic value for postoperative outcome after cardiac surgery with cardiopulmonary bypass (CPB), which itself is possibly causing a systemic inflammatory response syndrome (SIRS). METHODS Fifty patients with an isolated CRP-elevation (>5 mg/l) (from 6.2 to 93.3 mg/l) were operated using CPB (group A). A control group (group B) consisted of 50 cardiac surgery patients, matched in the patterns of age, gender and kind of disease. No preoperative CRP-elevation (from 0 to 4.8 mg/l) occurred in this group. RESULTS The postoperative course of both groups showed significant differences. Septic complications were seen more often in group A (20%) than in the controls (2%) (P < 0.01). Microbiology (blood culture, cultures from nose, tracheal aspirate and urine) was positive only in 10% of these patients. Catecholamine support (epinephrine, norepinephrine and/or doses of dopamine or dobutamine of more than 3 microg/kg per min) was needed in 26% of group A cases, whereas it was only needed in 10% of group B (P < 0.05). A significantly longer respiratory support was also necessary in patients with elevated CRP (25.2 +/- 6.4 h vs. 6.6 +/- 0.8 h) (P < 0.01). Furthermore there was a significant difference in the duration of intensive care (4.6 +/- 0.8 days vs. 2.6 +/- 0.3 days) (P < 0.05). CONCLUSIONS These data show that patients without apparent infection or inflammation, who had elevated CRP-values preoperatively, face an increased risk of septic complications after extracorporeal circulation. As microbiology tests are negative in most cases, it may be speculated that the majority of septic complications are due to a SIRS.

Heart-type fatty acid binding protein (hFABP) in the diagnosis of myocardial damage in coronary artery bypass grafting

OBJECTIVES Heart-type fatty acid binding protein (hFABP) is an intracellular molecule engaged in the transport of fatty acids through myocardial cytoplasm and has been used as a rapid marker of myocardial infarction. However, its value in the evaluation of perioperative myocardial injury has not yet been assessed. METHODS 32 consecutive patients undergoing coronary artery bypass grafting were included in a prospective, randomized study using standardized operative procedures and myocardial protection. Three patients with perioperative myocardial infarction were added. Serial blood samples were taken preoperatively, before ischemia, 5 and 60 min after declamping, 1 and 6 h postoperatively and on postoperative days 1, 2 and 10 and were tested for hFABP, creatine kinase isoenzyme MB (CKMB) and troponin I (TnI). RESULTS Hospital mortality was zero. The kinetics of the biochemical parameters revealed a typical pattern for each marker. In routine patients, hFABP levels peaked as early as 1 h after declamping, whereas CKMB and TnI peaked only 1 h after arrival in the intensive care unit. Patients with perioperative infarction displayed peak levels some hours later in all marker proteins. Peak serum levels of hFABP correlated significantly with peak levels of CKMB (r=0.436, P=0.011) and TnI (r=0.548, P=0.001), indicating the degree of myocardial damage. CONCLUSIONS hFABP is a rapid marker of perioperative myocardial damage and peaks earlier than CKMB or TnI. The kinetics of marker proteins in serial samples immediately after reperfusion is more suitable for the detection of perioperative myocardial infarction than a fixed cut-off level.

Intraaortic balloon pumping in patients with right ventricular insufficiency after cardiac surgery: parameters to predict failure of IABP Support.

BACKGROUND The indications for intra-aortic balloon pump (IABP) in the case of a failing right ventricle after operations with extracorporeal circulation (ECC) are still discussed controversially. We investigated the benefit of IABP in patients with a predominantly right ventricular dysfunction after ECC. Additionally, we wanted to identify early and easily available prognostic markers for outcome in all patients receiving IABP support. PATIENTS AND METHODS Between 1/2004 and 1/2008, 4550 patients underwent cardiac surgical procedures with ECC, 223 of whom (4.9 %) had an IABP inserted intra- or postoperatively (group 1). 79 of these patients were treated intraoperatively with IABP for early postoperative low cardiac output syndrome (LCOS) characterized by predominantly right ventricular failure (RV group). Clinical data and hemodynamic variables were recorded perioperatively. Multiple potential markers of mortality and postoperative complications were analyzed statistically, especially with regard to their predictive ability. RESULTS 68 % of all IABP patients were successfully weaned from IABP support and 63 % survived to hospital discharge. In the RV group, cardiac index (CI) and mean arterial pressure (MAP) increased (CI 1.8 +/- 0.2 to 2.8 +/- 0.2, MAP 53 +/- 10 to 73 +/- 8, P < 0.05) within 1 hour after IABP, whereas central venous pressure (CVP) and pulmonary artery wedge pressure (PAWP) decreased ( P < 0.05). 59 patients in the RV group (75 %) could be weaned from IABP successfully and 69 % survived to hospital discharge. Serum lactate of more than 11 mmol/L in the first 10 hours of IABP support predicted a 100 % mortality. A base deficit of more than 12 mmol/L, mean arterial pressure less than 55 mmHg, urine output of less than 50 ml/h for 2 hours, and dose of epinephrine or norepinephrine of more than 0.4 mg/kg/min were other highly predictive prognostic markers. Furthermore, multivariate analysis showed that patients with a left atrial pressure > 17 mmHg or a mixed venous saturation (SVO (2)) < 65 % had poor outcomes. CONCLUSIONS In patients with IABP support for postcardiotomy cardiogenic shock, elevated serum lactate, elevated base deficit, hypotension, oliguria and large vasopressor doses are all predictors of mortality. In these patients, the use of another mechanical assist device should be considered in good time. Our study additionally shows that LCOS caused by predominantly right ventricular failure - particularly after CABG - may be an additional indication for IABP.

Pulmonary carcinosarcoma: diagnostic problems and determinants of the prognosis.

OBJECTIVE Bronchopulmonary carcinosarcoma is a very rare tumor and the prognosis of patients with carcinosarcoma is assessed as unfavourable. The problems concerning diagnosis, therapy, and prognosis after resection treatment are discussed with reference to our seven cases and with consideration of the pertinent literature. METHODS The retrospective data of seven patients with pulmonary carcinosarcoma were analysed. All were staged postoperatively according to the international TNM staging system. The diagnosis was verified by immunohistochemical investigation. The prognosis of the patients with carcinosarcoma was compared with the prognosis of patients with non-small cell carcinoma of the lung. RESULTS Whether lung resection is the treatment of choice for these patients is of no relevance, because in most cases the preoperative diagnosis is incomplete, as only one component of the tumor, namely the epithelial one, is found in the biopsy specimen. The complete and correct diagnosis in five of the seven cases was not made before the resection had been performed and in the remaining two patients it was only made when tumor recurrence or metastases occurred. The prognosis of patients with carcinosarcoma of the lung is assessed to be comparable to that of patients with other pulmonary carcinoma: in this study survival times ranged from only 3 months (T2N3) to 4 years 6 months (T3N1). The causes of death of the patients with carcinosarcoma were local recurrence in four patients and metastases at distant sites in two. Two recurrent tumors as well as the metastases consisted only of the sarcoma component of the primary tumor histologically. CONCLUSION One may suggest that the prognosis of carcinosarcoma might be determined by the sarcoma component of the tumor. Therefore the generally accepted therapies of soft tissue sarcomas should be adopted for the follow-up treatment of patients with pulmonary carcinosarcoma.

Gene expression in acute Stanford type A dissection: a comparative microarray study

BackgroundWe compared gene expression profiles in acutely dissected aorta with those in normal control aorta.Materials and methodsAscending aorta specimen from patients with an acute Stanford A-dissection were taken during surgery and compared with those from normal ascending aorta from multiorgan donors using the BD Atlas™ Human1.2 Array I, BD Atlas™ Human Cardiovascular Array and the Affymetrix HG-U133A GeneChip®. For analysis only genes with strong signals of more than 70 percent of the mean signal of all spots on the array were accepted as being expressed. Quantitative real-time polymerase chain reaction (RT-PCR) was used to confirm regulation of expression of a subset of 24 genes known to be involved in aortic structure and function.ResultsAccording to our definition expression profiling of aorta tissue specimens revealed an expression of 19.1% to 23.5% of the genes listed on the arrays. Of those 15.7% to 28.9% were differently expressed in dissected and control aorta specimens. Several genes that encode for extracellular matrix components such as collagen IV α2 and -α5, collagen VI α3, collagen XIV α1, collagen XVIII α1 and elastin were down-regulated in aortic dissection, whereas levels of matrix metalloproteinases-11, -14 and -19 were increased. Some genes coding for cell to cell adhesion, cell to matrix signaling (e.g., polycystin1 and -2), cytoskeleton, as well as several myofibrillar genes (e.g., α-actinin, tropomyosin, gelsolin) were found to be down-regulated. Not surprisingly, some genes associated with chronic inflammation such as interleukin -2, -6 and -8, were up-regulated in dissection.ConclusionOur results demonstrate the complexity of the dissecting process on a molecular level. Genes coding for the integrity and strength of the aortic wall were down-regulated whereas components of inflammatory response were up-regulated. Altered patterns of gene expression indicate a pre-existing structural failure, which is probably a consequence of insufficient remodeling of the aortic wall resulting in further aortic dissection.

The pectoral muscle flaps in the treatment of bronchial stump fistula following pneumonectomy.

Between 1975 and June 1992, pneumonectomy was performed in 594 patients, of whom 33 (5.6%) developed bronchopleural fistulae postoperatively. Until 1989 25 cases were reoperated: 5 patients were treated by thoracoplasty primarily, 20 by repair of the stump with sutures and by covering the stump with pericardial tissue or intercostal muscle, of whom 10 suffered from empyema. In 5/20 patients (25%) chronic fistulae developed making further interventions necessary. Since 1989 seven patients with bronchial stump fistulae have been reoperated with a delay of less than 12 h after diagnosis. Surgery consisted of reclosure of the stump with sutures in five patients. In addition, every patient was treated with the intrathoracic transposition of a petiolated ipsilateral pectoral muscle graft, which was the only treatment in two patients. Neither recurrence of the bronchopleural fistula nor empyema was seen in this group of patients (0%). We conclude that bronchial stump fistulae in patients after pneumonectomy can be treated successfully by the use of pectoral muscle flaps either combined with a closure of the leak using sutures or as the only measure. The method proved to be simple, safe and without major impairment of the patient. In combination with early reintervention, postpneumonectomy empyema including a disfiguring thoracoplasty can thereby often be avoided.