Josef Margreiter

Experience with percutaneous venoarterial cardiopulmonary bypass for emergency circulatory support.

ObjectiveMechanical circulatory support can maintain vital organ perfusion in patients with cardiac failure unresponsive to standard pharmacologic treatment. The purpose of the current study was to report complication and survival rates in patients supported with emergency percutaneous venoarterial cardiopulmonary bypass because of prolonged cardiogenic shock or cardiopulmonary arrest. DesignRetrospective clinical study. SubjectsA total of 46 patients supported with venoarterial cardiopulmonary bypass, 25 because of cardiogenic shock unresponsive to pharmacologic therapy and 21 because of cardiopulmonary arrest unresponsive to standard advanced cardiac life support. ResultsIn 41 of the 46 patients (89%), stable extracorporeal circulation was established; in five patients (11%), femoral cannulation was accomplished only after a surgical cutdown. A total of 28 patients were weaned from cardiopulmonary bypass (19 of 25 patients with cardiogenic shock vs. 9 of 21 patients with cardiopulmonary arrest, p = .03), and 13 patients had long-term survival (10 of 25 patients with cardiogenic shock vs. 3 of 21 patients with cardiopulmonary arrest, p = .1). Complications directly related to the use of cardiopulmonary bypass were found in 18 patients (39%), major complications related to femoral cannulation being the most common single cause for bypass-associated morbidity (eight patients, 17%) ConclusionsLong-term survival rates after emergency percutaneous cardiopulmonary bypass are encouraging in patients with an underlying cardiocirculatory disease amenable to immediate corrective intervention (angioplasty, surgery, transplantation).

Continuous Positive Airway Pressure at 10 cm H2O During Cardiopulmonary Bypass Improves Postoperative Gas Exchange

Postbypass pulmonary dysfunction including atelectasis and increased shunting is a common problem in the intensive care unit. Negative net fluid balance and continuous positive airway pressure (CPAP) have been used to reduce the adverse effects of cardiopulmonary bypass (CPB) on the lung. To determi

Coagulation monitoring and management of anticoagulation during cardiac assist device support.

BACKGROUND The incidence of clinically significant thromboembolic events due to the use of cardiac assist device systems remains high. Despite the considerable advances in cardiac assist device technology, the monitoring and management of the hypercoagulable coagulation status, resulting from foreign surfaces of the assist device system, altered rheologic conditions, and blood stasis in the recipient heart remain a challenge. Moreover septic complications and insufficient anticoagulation are responsible for thromboembolic events. METHODS In addition to standard coagulation analysis, functional coagulation tests were performed including the use of a thrombelastographic monitoring system (ROTEG) and a platelet function analyzer (PFA-100). RESULTS Severe biventricular ischemic heart failure developed in a 58-year-old man with acute myocardial infarction and he needed a biventricular assist device for a bridge to cardiac transplantation. Although the patient received acenocoumarol (Sintrom; Novartis Pharma, Vienna, Austria) and acetylsalicylic acid (Aspisol; Bayer AG, Leverkusen, Germany) as usual, ROTEG and the PFA-100 detected hypercoagulability while routine coagulation screening tests showed hypocoagulability. Moreover thrombus formation surrounding the canula of the left ventricular assist device was detected. Antithrombotic therapy with clopidogrel (Plavix) was initiated. Coagulation was closely monitored with modified thrombelastography and the PFA-100 to achieve sufficient but not overwhelming anticoagulation therapy. Three months after biventricular assist device implantation the patient underwent successful transplantation with no major blood loss. CONCLUSIONS Thrombelastography should be the standard form of monitoring in such patients to decrease the risk of thromboembolic events and prevent bleeding complications.

Detection of Protamine and Heparin After Termination of Cardiopulmonary Bypass by Thrombelastometry (ROTEM®): Results of a Pilot Study

BACKGROUND: Our goal of this study was to determine whether protamine’s effects on coagulation can be detected and differentiated from those of heparin when using thrombelastometry (ROTEM®). METHODS: To reverse the effects of heparin after cardiopulmonary bypass (CPB), 22 consecutive patients undergoing aortocoronary bypass graft surgery were included. According to clinical routine, all patients received a first dose of protamine calculated from the total amount of heparin given; additional protamine (70 U/kg) was administered to patients with activated clotting time (ACT) above baseline and clinical signs of diffuse bleeding. Simultaneously, routine ACT measurements, ROTEM assays (heparin-sensitive INTEM, and heparinase-containing HEPTEM test) and standard coagulation tests were performed, and the activity of coagulation factors as well as antifactor Xa activity measured. RESULTS: Administration of additional protamine (n = 16) resulted in a statistically significant increase in coagulation times on the intrinsically activated test (INTEM-CT), namely from (mean [±sd]) 219.8 (±19.1) s to 241.1 (±21.7) s (P < 0.001), and on the heparinase-containing test (HEPTEM-CT), namely from 210.2 (±19.9) s to 226.8 (±21.8) s (P < 0.001). These changes were not observed in patients receiving a single protamine dose (n = 6). The INTEM-CT:HEPTEM-CT ratio correctly identified 56 of the 58 samples as not containing residual heparin and correctly detected residual heparin in 3 of the only 6 samples showing elevated antifactor Xa values after CPB. CONCLUSION: Our preliminary data show that at termination of CPB administration of additional protamine results in a brief prolongation of coagulation times on the INTEM and HEPTEM test and that ROTEM might be useful in excluding residual heparin in cases showing prolonged ACT.

Systolic anterior motion of the mitral valve with left ventricular outflow tract obstruction: three cases of acute perioperative hypotension in noncardiac surgery.

In this report we describe three cases of severe perioperative hypotension in noncardiac surgery patients. As systolic anterior motion of the mitral valve in combination with subaortic left ventricular outflow tract obstruction is an unrecognized cause for hypotension in noncardiac surgery patients, delayed diagnosis can result in erroneous treatment regimen. The aim of the present report is to provide an informative and brief synopsis of the pathophysiological consequences and diagnostic/therapeutic strategies for the perioperative management of systolic anterior motion.

The effects of perioperatively administered crystalloids and colloids on concentrations of molecular markers of activated coagulation and fibrinolysis.

To explore whether intravenous administration of routinely used crystalloid or colloid solutions differently affects the coagulation system, we investigated orthopaedic patients. Since crystalloid solutions might cause hypercoagulability, we here present our results on molecular markers of coagulation and fibrinolysis. Patients undergoing knee replacement surgery randomly received isovolemic amounts of lactated Ringers solution, 6% hydroxyethyl starch 200/0.5 or 4% modified gelatine. Arterial blood samples for determination of specific molecular markers of activated coagulation (thrombin/antithrombin complex, D-dimer, prothrombin fragment F1 + 2), fibrinolysis (plasmin/α2-antiplasmin complex, tissue plasminogen activator, plasminogen activator inhibitor-1), and concentrations of coagulation factor XIII were obtained at baseline, before tourniquet release, at the end of surgery and 2 h after operation. During the observation period, thrombin/antithrombin complex increased from 4.8 to 54.7 μg/l, D-dimer increased from 0.3 to 6.0 mg/ml, prothrombin fragment F1 + 2 increased from 1.7 to 5.9 nmol/l, tissue plasminogen activator decreased from 7.3 to 6.7 ng/ml, plasminogen activator inhibitor-1 increased from 68.4 to 71.0 ng/ml, plasmin/α2-antiplasmin complex increased from 281.5 to 884 μg/l and factor XIII decreased from 89.0 to 58.5%. All parameters changed significantly but without any detectable difference in the response profile between the groups receiving different intravenous fluids. During knee replacement surgery a pronounced activation of the coagulation/fibrinolytic system was observed, regardless of whether patients received crystalloid or colloid fluids. Thus, these results cannot confirm the hypothesis that crystalloid fluids per se cause hypercoagulability in vivo.

Aortic valve replacement in the conscious patient under regional anesthesia without endotracheal intubation

See related articles on pages 1204, 1394, and 1401. Minimally invasive operative procedures are of increasing interest to surgeons, including cardiac surgeons. Aside from the obvious advantage of reducing the surgical trauma, implementation of regional anesthesia is currently under investigation in heart surgery. Our aim was to determine the feasibility of using regional anesthesia without endotracheal intubation in aortic valve replacement with extracorporeal circulation in the conscious patient.

Slightly Elevated Serum Creatinine Predicts Renal Failure Requiring Hemofiltration after Cardiac Surgery

BACKGROUND Acute renal failure (ARF) after cardiac surgery is a serious adverse event that is associated with high perioperative mortality and prolonged hospitalization. The aim of our study was to evaluate pre- and intraoperative risk factors for the development of ARF requiring hemofiltration after cardiac surgery. METHODS From February 2002 through February 2003, 913 patients underwent cardiac surgery at our institution. Seventy-three patients developed ARF (8.1%), 16 patients were excluded from the study because of chronic end-stage renal insufficiency. Patient characteristics and operative variables were analyzed. A multivariate logistic regression analysis was performed to determine risk factors for ARF. RESULTS Patients who developed ARF were older (P < .001; odds ratio [OR], 1.084; 95% confidence interval [CI], 1.0371.133) than patients who did not develop ARF. Furthermore, cardiopulmonary bypass duration (P = .007; OR, 1.013; 95% CI, 1.004-1.032) and emergent surgery (P = .011; OR, 6.667; CI, 1.538-28.571) were predictive for development of ARF. The strongest predictor for ARF was a preoperative creatinine level >or=2 mg/dL (P < .001; OR, 97.519; 95% CI, 22.363425.252). Most interestingly, even moderately elevated preoperative creatinine levels (1.3-1.99 mg/dL) independently predict ARF after cardiac surgery (P = .001; OR, 3.838; 95% CI, 1.793-8.217). CONCLUSION Our data indicate that emergent surgery as well as advanced age and long duration of cardiopulmonary bypass independently predict ARF after cardiac surgery. Most importantly, even slightly impaired preoperative creatinine levels predict the development of ARF requiring hemofiltration after cardiac surgery.

The Impact of Business Cards on Physician Recognition After General Anesthesia

Despite their contribution to overall perioperative treatment of patients, anesthesiologists often remain in anonymity. We evaluated the impact of business cards on physician recognition after general anesthesia. Using a questionnaire, 441 patients were interviewed for recall of the anesthesiologist’s name, the surgeon’s name, and their overall satisfaction with anesthetic care 6 wk after undergoing surgery during general anesthesia. Of these patients, 155 had and 137 had not randomly received a business card during the preoperative visit, with another 149 patients serving as a control group. Business card recipients responded significantly more frequently than did nonrecipients or patients from the control group (65.8% vs 54.7% vs 53%), with recall of the anesthesiologist’s name being significantly more frequent in the Business Card Recipient group (51.5% vs 14.3% vs 11.4%). Patient satisfaction with anesthetic care and recall of the surgeon’s name were similar in all groups. The use of a simple tool such as a business card can indeed produce a measurable positive change in physician recognition on the part of the patient.

Ongoing procedure development in robotically assisted totally endoscopic coronary artery bypass grafting (TECAB).

BACKGROUND Totally endoscopic coronary artery bypass grafting (TECAB) using robotics requires stepwise introduction into a heart surgery program. It is the aim of this study to evaluate the state of procedure development after continued application of telemanipulation techniques in the clinical setting. We also sought to assess perioperative and intermediate term clinical results after robotically assisted CABG. PATIENTS AND METHODS From June 2001 to March 2005, robotically assisted CABG using the daVinci system was carried out in 107 patients with single and multi-vessel coronary artery disease. The following procedures were performed: robotically assisted endoscopic left internal mammary artery (LIMA) harvesting and completion of the procedure as conventional CABG, MIDCAB, or OPCAB (n = 22), robotically assisted suturing of LIMA-to-LAD anastomoses during conventional CABG (n = 28), TECAB on the arrested heart using remote access perfusion (n = 48), TECAB on the beating heart using an endostabilizer (n = 8), takedown of adhesions (TECAB intended) (n = 1). RESULTS Hospital mortality was 0% and cumulative risk adjusted mortality reached 1.6 lives saved versus EuroSCORE predictions. Undesirable surgical events (USE) such as conversion, on table revision, or postoperative revision procedures occurred in 34 out of 107 (32%) patients. Median ventilation time and ICU stay, however, were 11(0-278) hours and 21(11-389) hours, respectively. Cumulative 3 years survival was 100% and freedom from angina at 3 years was 97%. CONCLUSIONS We conclude that despite being surgically challenging robotically assisted coronary artery surgery can be implemented with acceptable safety. TECAB procedures have reached a reproducible state. Perioperative mortality after robotically assisted CABG may be lower than predicted. Intermediate term clinical results are very satisfactory.