Pieter J.A. van der Starre

Dexmedetomidine and the Reduction of Postoperative Delirium after Cardiac Surgery

BACKGROUND Delirium is a neurobehavioral syndrome caused by the transient disruption of normal neuronal activity secondary to systemic disturbances. OBJECTIVE The authors investigated the effects of postoperative sedation on the development of delirium in patients undergoing cardiac-valve procedures. METHODS Patients underwent elective cardiac surgery with a standardized intraoperative anesthesia protocol, followed by random assignment to one of three postoperative sedation protocols: dexmedetomidine, propofol, or midazolam. RESULTS The incidence of delirium for patients receiving dexmedetomidine was 3%, for those receiving propofol was 50%, and for patients receiving midazolam, 50%. Patients who developed postoperative delirium experienced significantly longer intensive-care stays and longer total hospitalization. CONCLUSION The findings of this open-label, randomized clinical investigation suggest that postoperative sedation with dexmedetomidine was associated with significantly lower rates of postoperative delirium and lower care costs.

Factors Portending Endoleak Formation After Thoracic Aortic Stent-Graft Repair of Complicated Aortic Dissection

Background—Endoleaks after stent-graft repair of aortic dissections are poorly understood but seem substantially different from those seen after aneurysm repair. We studied anatomic and clinical factors associated with endoleaks in patients who underwent stent-graft repair of complicated type B aortic dissections. Methods and Results—From 2000 to 2007, 37 patients underwent stent-graft repair of acute (≤14 days; n=23), subacute (15 to 90 days; n=10) or chronic (>90 days; n=4) complicated type B aortic dissections using the Gore Thoracic Excluder (n=17) or TAG stent-grafts (n=20) under an investigator-sponsored protocol. Endoleaks were classified as imperfect proximal seal, flow through fenestrations or branches, or complex (both). Variables studied included coverage of the left subclavian artery, aortic curvature, completeness of proximal apposition, dissection chronicity, and device used. Endoleaks were found during follow-up (mean, 22 months) in 59% of patients, and they were associated with coverage of the left subclavian artery (complex, P<0.001), small radius of curvature (type 1 and complex, P=0.05), and greatest length of unapposed proximal stent graft (complex, P<0.0001). During follow-up, 10 endoleaks resolved spontaneously, 6 required reintervention for false lumen dilatation, and 2 were stable without clinical consequences. Conclusions—Endoleaks are common after stent-graft repair of aortic dissection and may lead to false lumen enlargement necessitating reintervention. Anatomic complexities such as acute aortic curvature and covered side branches were associated with endoleaks, illustrating the need for dissection-specific device development.

Factors portending endoleak formation after thoracic aortic stent-graft repair of aortic dissection

Background—Endoleaks after stent-graft repair of aortic dissections are poorly understood but seem substantially different from those seen after aneurysm repair. We studied anatomic and clinical factors associated with endoleaks in patients who underwent stent-graft repair of complicated type B aortic dissections. Methods and Results—From 2000 to 2007, 37 patients underwent stent-graft repair of acute (≤14 days; n=23), subacute (15 to 90 days; n=10) or chronic (>90 days; n=4) complicated type B aortic dissections using the Gore Thoracic Excluder (n=17) or TAG stent-grafts (n=20) under an investigator-sponsored protocol. Endoleaks were classified as imperfect proximal seal, flow through fenestrations or branches, or complex (both). Variables studied included coverage of the left subclavian artery, aortic curvature, completeness of proximal apposition, dissection chronicity, and device used. Endoleaks were found during follow-up (mean, 22 months) in 59% of patients, and they were associated with coverage of the left subclavian artery (complex, P<0.001), small radius of curvature (type 1 and complex, P=0.05), and greatest length of unapposed proximal stent graft (complex, P<0.0001). During follow-up, 10 endoleaks resolved spontaneously, 6 required reintervention for false lumen dilatation, and 2 were stable without clinical consequences. Conclusions—Endoleaks are common after stent-graft repair of aortic dissection and may lead to false lumen enlargement necessitating reintervention. Anatomic complexities such as acute aortic curvature and covered side branches were associated with endoleaks, illustrating the need for dissection-specific device development.

Late profound muscle weakness following heart transplantation due to Danon disease.

Introduction: Postoperative muscle weakness is a serious complication in surgical intensive care patients. It is mostly described as critical illness polyneuromyopathy. Risk factors include intensive care length of stay, sepsis, poor glycemic control, and combined use of corticosteroids and neuromuscular blocking agents, malnutrition, and electrolyte imbalance. Methods: We report a case of late‐progressive, profound weakness after heart transplantation for noncompaction cardiomyopathy which required prolonged mechanical ventilation. The patients muscle strength recovered completely after prolonged rehabilitation. Results: Electromyographic assessment showed myopathy. Muscle biopsy revealed Danon disease, a genetic disorder affecting the lysosomal‐associated membrane protein 2 gene (LAMP2). Conclusions: The finding of this genetic disorder was unexpected, because the preoperative echocardiographic diagnosis of noncompaction cardiomyopathy has not been reported in Danon disease. This report underlines the need for early availability of pathology results from the explanted heart, which showed the same disorder. Muscle Nerve, 2013

Factor VIII Inhibitor Bypass Activity and Recombinant Activated Factor VII in Cardiac Surgery

OBJECTIVE Postcardiopulmonary bypass hemorrhage remains a serious complication of cardiac surgery. Given concerns regarding adverse effects of blood product transfusion and limited efficacy of current antifibrinolytics, procoagulant medications, including recombinant factor VIIa (rFVIIa) and factor eight inhibitor bypass activity (FEIBA), increasingly have been used in managing refractory bleeding. While effective, these medications are associated with thromboembolic complications. This study compared the efficacy and risk of adverse events of rFVIIa and FEIBA in cardiac surgical patients with refractory bleeding. DESIGN This retrospective study evaluated 168 patients who underwent cardiac surgery and received either FEIBA or rFVIIa to manage postbypass hemorrhage. Demographic, clinical, and outcomes data were collected and statistical analysis performed to compare thromboembolic event rates, relative efficacy, and 30-day mortality following administration of these medications. SETTING Single university hospital. PARTICIPANTS Patients undergoing cardiac surgery. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULT Sixty-one patients received rFVIIa, and 107 received FEIBA. Demographics, surgical procedures, and preoperative anticoagulation were similar between the cohorts; however, the rFVIIa cohort had longer durations of cardiopulmonary bypass (305.1 v 243.8 min, p<0.01). There were no significant differences in the number of thromboembolic events, 30-day mortality, or rates of revision surgery. Neither group demonstrated a clear relationship between dosage and occurrence of thromboembolic events. The rFVIIa cohort received more platelets than the FEIBA cohort (3.13 v 1.67 units, p = 0.01), but transfusion rates of other blood products were similar. CONCLUSIONS This study suggests that rFVIIa and FEIBA have similar efficacy and adverse event profiles in managing intractable postbypass hemorrhage in cardiac surgical patients. Further prospective studies are required.

Unexpected Findings During the Anesthetic Management of a Patient With a Cardiac Paraganglioma

ARDIAC PARAGANGLIOMA is a rare and mostly benign neoplasm, arising from neuroendocrine cells, similar to pheochromocytoma in the adrenal glands. Endocrinologically active tumors may cause hypertension, arrhythmias, and other cardiac symptoms and mostly arise from the left atrium.1 Significant hemodynamic derangement may be encountered during anesthetic management and surgical manipulation. Paraganglioma without catecholamine secretion usually presents with symptoms of superior vena cava obstruction, pericardial effusion, or tamponade. 2 Some unexpected findings in a patient who underwent resection of a catecholamine-secreting cardiac paraganglioma are presented. CASE REPORT An otherwise healthy 67-year-old woman, with no prior relevant medical history, presented to the emergency room with a sudden onset of episodic tachyarrhythmias as well as multiple episodes of chest, arm, and jaw pain. The electrocardiogram showed T-wave inversions in leads V1 to V3 and Q waves in leads III and aVF. There were no symptoms of congestive heart failure. Coronary angiography revealed abnormal branches from the left anterior descending coronary artery and the conus of the right coronary artery (RCA) feeding a vascular mass medial to the right atrial appendage and anterior to the aorta, overlying the origin of the right coronary artery. Transthoracic echocardiography showed an extracardiac mass (4 6 4 cm) adjacent to the right atrium. The mass was also observed on a thoracic computed tomography (CT) scan (Fig 1). A small pericardial effusion was observed at the time. Transvascular biopsy of the mass, accessed through the right internal jugular vein, revealed pathology consistent with paraganglioma. Serum catecholamine levels of dopamine (345 pg/mL) and norepinephrine (526 pg/mL) were mildly elevated, with normal epinephrine (10 pg/mL) levels. Preoperative treatment with phenoxybenzamine, 10 mg orally twice a day, with close outpatient blood pressure monitoring was initiated. The patient was scheduled for surgical resection 2.5 months after the biopsy with stable blood pressure and no additional cardiac symptoms. Additional treatment with -blocking agents was not initiated because of the patient’s relatively low resting heart rate (62 beats/min). After arrival in the operating room, a preinduction arterial catheter was placed, and blood samples were taken for catecholamine levels (Table 1). The patient’s blood pressure was 140/75 mmHg, and her heart rate was 65 beats/min. Anesthesia was induced with fentanyl, 8 g/kg, etomidate, 20 mg, and rocuronium, 1 mg/kg intravenously, without causing any hemodynamic derangement. During laryngoscopy, the patient developed profound bradycardia progressing to asystole, lasting 8 seconds (by continuous recording), which spontaneously resolved once laryngoscopy was completed. No cardiopulmonary resuscitation or pharmacologic interventions were required. Anesthesia was maintained with sevoflurane, fentanyl, and rocuronium. After central venous catheter placement into the right internal jugular vein, the recorded initial central venous pressure (CVP) was 22 mmHg. A transesophageal echocardiography (TEE) probe was placed revealing a significant amount of pericardial effusion (Fig 2). A richly vascularized mass could be observed in the upper anterior region of the right ventricle (Fig 3). All valves appeared to be competent, myocardial contractility was preserved, and regional wall motion abnormalities were not observed. After median sternotomy and opening of the pericardium, 350 mL of clear pericardial fluid were evacuated; CVP immediately decreased to 15 mmHg. The tumor was visible anterior to the aorta and had a distinct vascular blush appearance. With the use of cardiopulmonary bypass and cardioplegic arrest, the tumor could be completely resected without injury to the RCA. Electrocautery and suture ligation of feeding vessels were used. There were no signs of additional tumor presence in the heart. The pericardial fluid was sent for cytology. After successful weaning from cardiopulmonary bypass, blood samples were taken for repeat assessment of catecholamine levels (Table 1). The patient was hemodynamically stable after resection of the mass and did not require any vasoactive medications to support her blood pressure. The postoperative course was uncomplicated, and she was discharged on postoperative day 4. Pathology of the mass confirmed the diagnosis of paraganglioma with an intact capsule. The cytology of the pericardial fluid was negative.

Vancomycin plasma concentrations in cardiac surgery with the use of profound hypothermic circulatory arrest.

OBJECTIVE This study was undertaken to compare the effect of deep hypothermic circulatory arrest, compared with moderate hypothermia, on the plasma concentrations and pharmacokinetic profile of vancomycin, administered as prophylaxis, in patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS Two groups of adult cardiac surgery patients were prospectively studied. One group consisted of 12 patients undergoing valvular surgery with moderate hypothermia, and another group was of 12 patients undergoing surgery with the use of profound hypothermic circulatory arrest. Vancomycin was administered before skin incision, and plasma levels were measured at regular intervals for 24h. RESULTS The plasma concentrations of vancomycin showed a similar pattern in both groups. The pharmacokinetic profile showed a three-compartment model in both groups. CONCLUSION The dosing of vancomycin, if used as antibiotic prophylaxis, does not need to be adjusted in cardiac surgery patients when undergoing profound hypothermic circulatory arrest, since the plasma concentrations and pharmacokinetic profile are similar to patients with moderate hypothermia. The pharmacokinetic profile, consisting of three compartments, was not changed by the differences in temperature.

Transesophageal Echocardiography Guidance for Stent-Graft Repair of a Thoracic Aneurysm is Facilitated by the Ability of Partial Stent Deployment

Transesophageal echocardiography (TEE) is routinely used in our Institution for monitoring correct positioning of thoracic aortic stent grafts. We present a case of successful endovascular repair of three discrete thoracic aortic aneurysms with Zenith TX2 endovascular stent grafts in an 82-year-old female patient. Our focus is on the increased value of TEE guidance because of the ability of partial stent deployment and manipulation during insertion.

Obstruction of Pulmonary Artery Catheterization Because of Lipomatous Hypertrophy of the Interatrial Septum

pulm a s s OMPLICATIONS WITH CORRECT POSITIONING of a pulmonary artery catheter are not uncommon in the erioperative and intensive care settings.1 Common causes f difficult placement include misdirection into the innomnate vein or inferior vena cava, curling of the catheter in the ight ventricle, the obstructing presence of multiple paceaker wires, low-output states, and hypovolemia. In addiion, structural abnormalities may hinder successful catheerization. Lipomatous hypertrophy of the interatrial septum LHIS) is a common anatomic variant that results from fatty nfiltration of the septum with sparing of the fossa ovalis.2 he authors report a case in which pulmonary artery catheerization was impeded by LHIS. Transesophageal echocariography (TEE) was used to facilitate the passage of the atheter beyond the obstruction.

Choice of anesthetics.

The choice of anesthetics for vascular surgical patients is not only determined by the kind and extent of the surgical procedure but also by patient comorbidities. Frequently, patients have a history of hypertension, peripheral vascular and coronary artery disease,cerebrovascular disease, and renal impairment. The goal of the chosen anesthetic technique is to protect organ function, mainly of the brain and the heart. In some instances regional anesthesia might be preferred, but no difference in outcome between the two techniques has been shown conclusively. Vascular emergencies are particularly challenging for the anesthesiologist, but in recent years the development of stent graft insertion has improved the short-term outcome in many of these procedures.