Eckhard Schmid

Anaphylactic Reaction After Systemic Application of Aprotinin Triggered by Aprotinin-Containing Fibrin Sealant

We report a 67-yr-old male after multiple surgical procedures for treatment of arterial occlusive disease who suffered an anaphylactic reaction after administration of aprotinin (Trasylol) prior to urgent coronary artery bypass surgery. The patient had been treated with aprotinin-containing fibrin sealant in 2004 and in 2007, 2 wk before coronary artery bypass surgery. The postoperative serologic screening revealed positive results for qualitative aprotinin-specific IgG, highly elevated quantitative aprotinin-specific IgG and moderately elevated aprotinin-specific IgE antibodies.

Using reagent-supported thromboelastometry (ROTEM®) to monitor haemostatic changes in congenital heart surgery employing deep hypothermic circulatory arrest

OBJECTIVE Cardiac surgery employing cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) can induce coagulation disturbances and bleeding complications that may be especially severe in infants. A better understanding of the coagulopathy and a quick method for its evaluation would be helpful in the management of patients exposed to CPB and DHCA. This study aimed to monitor coagulation defects in congenital heart surgery using rotational thromboelastometry (ROTEM), standard coagulation tests and platelet flow cytometry. METHODS The study comprised 10 infants undergoing surgery for congenital heart disease on CPB and DHCA. Blood was sampled at skin incision, after heparinisation during CPB (directly pre- and directly post-DHCA) and after protamine administration post-CPB. ROTEM using different reagents including a heparinase-containing assay to evaluate coagulation during heparinisation, APTT and INR, and flow cytometry to evaluate platelet activation were performed. RESULTS During CPB, the ROTEM indicated CPB-induced clotting factor depletion and platelet dysfunction that persisted after CPB and heparin neutralisation. ROTEM results were available within 15 min and therefore much faster than standard tests. ROTEM-guided specific blood product treatment resulted in satisfactory coagulatory function. The highest degree of platelet activation was found directly after DHCA. CONCLUSIONS A major benefit of ROTEM is the quick detection of a developing coagulopathy already during CPB. ROTEM guides quick and specific blood product treatment after CPB, which may decrease bleeding complications in cardiac surgery. The finding of maximal platelet activation directly after DHCA suggests that not only CPB but also hypothermia activates platelets in vivo, thereby contributing to platelet dysfunction.

The volatile anesthetic sevoflurane inhibits activation of neutrophil granulocytes during simulated extracorporeal circulation.

Extracorporeal circulation (ECC) is an essential tool for the execution of cardiac operations. However, ECC is also associated with undesirable side effects. These include the induction of a systemic inflammatory response associated with leukocyte activation and cytokine release as well as potentially life-threatening complications. The volatile anesthetic sevoflurane has been reported to exert anti-ischemic and anti-inflammatory effects. We therefore investigated whether sevoflurane modulates the ECC-triggered inflammatory response. Heparinized human blood was circulated for 90 min in a normothermic (37°C) ex vivo ECC circuit. An air-oxygen mixture was administered via an oxygenator in controls (n=5). Sevoflurane (2 vol.%) was added to the gas mixture in a second group (n=5). At baseline and after 30, 60 and 90 min of ECC, blood samples were taken. In each sample whole blood counts were determined. Expression of the activation-indicating Mac-1 receptor on granulocytes and monocytes as well as leukocyte-platelet aggregate formation was measured in flow cytometry. Levels of the granulocyte activation marker PMN-elastase and of the cytokines IL-1β, IL-8 and TNF-α were analyzed using ELISA. ECC induced significant increases in Mac-1 expression on granulocytes (p<0.001) and PMN-elastase release (p<0.001). Sevoflurane decreased granulocyte Mac-1 expression during ECC (p<0.05) and inhibited the ECC-induced PMN-elastase release (p<0.05). Sevoflurane had no effect on whole blood cell counts, leukocyte-platelet aggregate formation and cytokine release during ECC. Sevoflurane inhibits granulocyte activation during ex vivo ECC and therefore has the potential to decrease the ECC-triggered inflammatory response. This promising finding warrants further investigation under clinical conditions.

Echocardiographic-Guided Placement of Venous Cannula Due to Inferior Vena Cava Obstruction Through a Large Eustachian Valve

CASE DESCRIPTION A 75-year-old man was referred for coronary artery bypass surgery after a recent diagnosis of coronary artery disease. The patient was taken to the operating room and anesthesia was induced uneventfully. The preoperative transthoracic echocardiogram was consistent with normal left ventricular function and transesophageal echocardiography (TEE) was not considered to be critical for intraoperative management in this case, and because of surgeon request, intraoperative TEE monitoring was not performed initially. The left internal mammary artery was harvested and the aorta cannulated uneventfully. Next, placement of a 2-stage venous cannula (36F/51F) was attempted through the superior aspect of the right atrium (RA) for gravity-dependent drainage. However, advancement of the cannula into the inferior vena cava (IVC) was not possible because of an elastic resistance at the level of the lower aspect of the RA. Mechanical manipulation of the RA and the right ventricle did not facilitate placement of the venous cannula, yet resulted in hemodynamic instability of the patient. To evaluate the underlying cause, a TEE probe was placed and a eustachian valve (2.6 cm maximum length) identified at the junction of IVC to the RA on midesophageal bicaval view at 83° rotation (Fig. 1). The surgeon attempted to place the 2-stage venous cannula under direct echocardiographic guidance but this recurrently resulted in advancement of the eustachian valve into the IVC orifice and obstruction of the IVC (Fig. 2) (Video 1, see Supplemental Digital Content 1, http://links.lww.com/AA/A142; see Appendix for Video 1 caption). The surgeon then decided to place a larger size single-stage venous cannula (32F), usually placed during bicaval cannulation, under direct TEE guidance into the RA, which was successful; a retrograde venous cannula was not placed. Venous drainage for cardiopulmonary bypass (CPB) was excellent, the further operative course uneventful, and the patient left the hospital on postoperative day 6.

Influence of Intraaortic Balloon Pump Counterpulsation on Transesophageal Echocardiography Derived Determinants of Diastolic Function

Introduction Intraaortic balloon pump counterpulsation (IABP) is often used in patients with acute coronary syndrome for its favourable effects on left ventricular (LV) systolic function and coronary perfusion. However, the effects of IABP on LV diastolic function have not been comprehensively investigated. Acute diastolic dysfunction has been linked to increased morbidity and mortality. The aim of this study was to examine the influence of IABP on LV diastolic dysfunction using standard TEE derived parameters. Methods Intraoperative TEE was performed in 10 patients (mean age 65 ± 11 yrs) undergoing urgent coronary artery bypass graft surgery (CABG), who had received an IABP preoperatively. TEE derived measures of diastolic dysfunction included early to late transmitral Doppler inflow velocity ratio (E/A), deceleration time (Dt), pulmonary venous systolic to diastolic Doppler velocity ratio (S/D), transmitral propagation velocity (Vp), and the ratio of early to late mitral annular tissue Doppler velocities (e’/a’). Statistical analyses included the Wilcoxon Sign-Rank test, and a p<0.05 was considered significant. Results Transmitral inflow E/A ratios increased significantly from 0.86 to 1.07 (p < 0.05), while Dt decreased significantly from 218 to 180 ms (p < 0.05) with the use of IABP. Significant increases in Vp (34 cm/s to 43 cm/s; p < 0.05), and e’/a’ (0.58 to 0.71; p < 0.05) suggested a favourable influence of intraaortic counterpulsation on diastolic function. Conclusion The use of perioperative IABP significantly improves TEE derived parameters of diastolic function consistent with a favourable impact on LV relaxation in cardiac surgery patients undergoing CABG.

Safety of transesophageal echocardiography during extracorporeal life support

Introduction: Use of extracorporeal life support (ECLS) has significantly increased in critically ill patients refractory to medical management. ECLS requires systemic anticoagulation to avoid thromboembolic complications and superimposed coagulopathies are common. Transesophageal echocardiography (TEE) is frequently employed to assess cannula position and cardiac function during extracorporeal therapy. The goal of this study was to assess whether TEE probe insertion and removal in systemically anticoagulated ECLS patients was safe compared to patients without ECLS and normal coagulation studies. Methods: Eighty-seven separate TEE examinations in 53 adult ECLS patients were analyzed. Detailed complication profiles were logged for each patient from initiation through discontinuation of ECLS. Routine coagulation testing was recorded within two hours prior to the TEE exams. Controls consisted of age- and gender-matched patients undergoing perioperative TEE without ECLS and normal coagulation (N=87). Results: Overall TEE-associated morbidity in ECLS patients was 2.3% and consisted of minor oropharyngeal bleeding (2/87 TEE exams) exclusively. The patients presenting with oropharyngeal bleeding received heparin for anticoagulation and had two or more abnormal coagulation studies at the time of TEE. Seventy-nine percent of ECLS patients received intravenous heparin infusions, 6.8% argatroban and 3.4% epoprostenol. Ten-point-eight percent of patients were not anticoagulated at the time of TEE because of pre-existing bleeding complications and/or deranged plasmatic coagulation profiles. No major complications (e.g., esophageal perforation, gastrointestinal bleeding, accidental extubation) were recorded in either group. Conclusions: TEE remained safe in critically ill patients under ECLS, despite systemic anticoagulation, during probe insertion, manipulation and removal. TEE-related complications pertained solely to oropharyngeal bleeding amenable to conservative management.

2D Echocardiographic Evaluation of Right Ventricular Function Correlates With 3D Volumetric Models in Cardiac Surgery Patients

OBJECTIVES The early diagnosis and treatment of right ventricular (RV) dysfunction are of critical importance in cardiac surgery patients and impact clinical outcome. Two-dimensional (2D) transesophageal echocardiography (TEE) can be used to evaluate RV function using surrogate parameters due to complex RV geometry. The aim of this study was to evaluate whether the commonly used visual evaluation of RV function and size using 2D TEE correlated with the calculated three-dimensional (3D) volumetric models of RV function. DESIGN AND SETTING Retrospective study, single center, University Hospital. PARTICIPANTS AND INTERVENTION Seventy complete datasets were studied consisting of 2D 4-chamber view loops (2-3 beats) and the corresponding 4-chamber view 3D full-volume loop of the right ventricle. RV function and RV size of the 2D loops then were assessed retrospectively purely qualitatively individually by 4 clinician echocardiographers certified in perioperative TEE. Corresponding 3D volumetric models calculating RV ejection fraction and RV end-diastolic volumes then were established and compared with the 2D assessments. MEASUREMENTS AND MAIN RESULTS 2D assessment of RV function correlated with 3D volumetric calculations (Spearmans rho -0.5; p<0.0001). No correlation could be established between 2D estimates of RV size and actual 3D volumetric end-diastolic volumes (Spearmans rho 0.15; p = 0.25). CONCLUSION The 2D assessment of right ventricular function based on visual estimation as frequently used in clinical practice appeared to be a reliable method of RV functional evaluation. However, 2D assessment of RV size seemed unreliable and should be used with caution.

Severe Upper Airway Obstruction After Intraoperative Transesophageal Echocardiography in Pediatric Cardiac Surgery: A Retrospective Analysis*

Objectives: The aim of this study was to evaluate if there is a correlation between the use of intraoperative transesophageal echocardiography and an increased rate of extubation failure and to find other risk factors for severe upper airway obstructions after pediatric cardiac surgery. Design: Retrospective analysis. Setting: Cardiac PICU. Patients: Patients 24 months old or younger who underwent surgery for congenital heart disease with cardiopulmonary bypass were retrospectively enrolled and divided into two groups depending on whether they received an intraoperative transesophageal echocardiography or not. We analyzed all cases of early reintubations within 12 hours after extubation due to a documented upper airway obstruction. Intervention: None. Measurements and Main Results: From a total of 424 patients, 12 patients (2.8%) met our criteria of early reintubation due to upper airway obstruction. Ten of 207 children in the transesophageal echocardiography group had to be reintubated, whereas only two of the 217 children in the control group had to be reintubated (4.8% vs 0.9%; p = 0.018). Logistic regression analysis showed a significant correlation between use of intraoperative transesophageal echocardiography and extubation failure (odds ratio, 5.64; 95% CI, 1.18–27.05; p = 0.030). There was no significant relationship among sex (odds ratio, 4.53; 95% CI, 0.93–22.05; p = 0.061), weight (odds ratio, 1.07; 95% CI, 0.82–1.40; p = 0.601), duration of surgery (odds ratio, 1.04; 95% CI, 0.74–1.44; p = 0.834), duration of mechanical ventilation (odds ratio, 1.00; 95% CI, 0.99–1.00; p = 0.998), and occurrence of trisomy 21 (odds ratio, 3.47; 95% CI, 0.83–14.56; p = 0.089). Conclusions: Although the benefits of intraoperative transesophageal echocardiography during pediatric cardiac surgery are undisputed, it may be one factor which could increase the rate of severe upper airway obstruction after extubation with the need for reintubation. We suggest to take precautions before extubating high-risk patients, especially in young male children with genetic abnormalities after cardiac surgery with cardiopulmonary bypass.

Left Ventricular Thrombus During Cardiopulmonary Bypass as the Primary Manifestation of Heparin-Induced Thrombocytopenia

Fig 1. The platelet count profile. The first value was obtained before coronary angiography and enoxaparin exposure (day 0). The second value was obtained on the preoperative morning before CPB (pre-CPB) 16 days after exposure to enoxaparin (day 16). The third value was obtained on admission to the ICU (post-CPB). Further values were obtained on postoperative (PO) days 1 through 7.

Recovery of residual curarization after red blood cell transfusion

Summary Background The muscle-relaxing effects of succinylcholine are terminated via hydrolysis by plasma cholinesterase. There are multiple genetic variants of this enzyme and clinical circumstances that might influence the activity of plasma cholinesterase and eventually lead to prolonged neuromuscular blockade following succinylcholine application. Case Report Here, we report a parturient woman with atonic bleeding who suffered significant blood loss (hemoglobin 6.0 g·dL−1). For surgical curettage, general anesthesia was performed by using short-acting succinylcholine. By the end of the 105-minute procedure, the patient’s trachea was extubated. After extubation she showed signs of the prolonged neuromuscular blocking action of succinylcholine. At this time, the patient received an AB0-compatible red blood cell transfusion and recovered instantly from neuromuscular blockade. The plasma cholinesterase (3.200 U·L−1) was below the normal range (4.900–12.000 U·L−1). Patient’s blood DNA analysis revealed heterozygously the genetic K variant of plasma cholinesterase. After red blood cell transfusion, serum potassium was elevated (5.7 mmol·L−1; 4.4 mmol·L−1 prior to transfusion). Conclusions Pregnancy, blood loss and genetic variation contributed to impairment of plasma cholinesterase. Due to high-speed red blood cell transfusion, hemolytic release of erythrocyte cholinesterase might have terminated the neuromuscular blocking succinylcholine effect.