Intraoperative Doppler tissue imaging with pulsed wave Doppler is a rapid method to determine the direction, timing, and velocity of regional longitudinal myocardial motion and quantify systolic and diastolic function. Although DTI provides regional measurements, sampling from different sites will help compensate for any differences, facilitating the evaluation of global EF and diastolic function and the calculation of filling pressures. Repeated DTI observations in the same patient enable the detection of regional ischemia, and the appearance or detection of postsystolic shortening is a sensitive index of ischemic but viable myocardium. DTI has also been used to detect subclinical ventricular dysfunction in asymptomatic patients with valvular disease and differentiate physiologic from pathologic hypertrophy and distinguish constrictive pericarditis from cardiomyopathy.
Measures to minimize myocardial damage have been an important target of research; therefore, a better understanding of the role of anesthetics in the prevention of myocardial injury may provide anesthesiologists with strategies to improve outcome. Myocardial ischemia initiates a range of cellular events, which are initially mild and become progressively damaging with increasing duration of ischemia. Perioperative myocardial ischemia is a serious adverse event that can increase morbidity and mortality after cardiac and noncardiac surgery. Several treatment approaches that prevent or lessen myocardial ischemia during and after surgery have been proposed. The use of particular anesthetics for the induction and maintenance of general anesthesia is one approach to protect against the adverse effects of ischemia. Experimental data indicate that some anesthetics, such as volatile general anesthetics, exert protective effects against ischemia–reperfusion injury that are independent of their hemodynamic effects. To approach this subject, several points should be well understood, such as myocardial metabolism, the pathophysiology of myocardial ischemia, myocardial stunning and hibernation, the effects of ischemia on myocardial metabolism, reperfusion injury, preconditioning, myocardial protection, temperature control, cardioplegia, ischemic and anesthetic preconditioning, and pharmacotherapy.
During coronary artery bypass grafting (CABG), both the quality of myocardial protection and the preoperative myocardial status directly influence the postoperative cardiac outcome, recovery, and complications. The aim of this study was to compare the protective effects of continuous retrograde cold blood cardioplegia with intermittent antegrade cold blood cardioplegia at systemic normothermia on left ventricular (LV) and right ventricular (RV) systolic and diastolic functions in patients with poor myocardial contractility, who underwent CABG surgery, in terms of the intraoperative course and the postoperative clinical outcome.
Patients were randomly divided into two equal groups (20 patients each) according to the myocardial protection technique: antegrade group: intermittent antegrade cold blood cardioplegia and retrograde group: continuous retrograde cold blood cardioplegia. In the antegrade group, warm cardioplegia was administered through an aortic root catheter with infusion pressure not exceeding 150 mmHg. The initial dose used was 10 ml/kg, followed by 5 ml/kg every 30 min afterwards. In the retrograde group, cardioplegia was administered through a coronary sinus cannula at the same volume and composition, but with pressure not exceeding 40 mmHg and was continuously infused. Systemic temperature was allowed to drift to 35πC. Hemodynamic parameters were recorded after induction of anesthesia, after weaning from bypass, and before transportation to ICU. Transesophageal echocardiography examination (for the assessment of RV and LV systolic and diastolic functions) was carried out at the same time points. Cardiac enzymes and serum lactate were measured after induction, after weaning from bypass, and 8 h postoperatively. Clinical outcomes in terms of the use of postoperative inotropic support or the need for defibrillation or pacing were recorded. Electron microscopic evaluation of RV and LV biopsies was carried out using a semiquantitative method with scoring from 0 (apparently normal) to 3 (severely damaged).
Electron microscopic evaluation of LV and RV myocardial biopsies indicated significantly less cellular edema, mitochondrial degeneration, and myofibrillar damage in the retrograde group as compared with the antegrade group. Echo data showed no statistically significant difference between the antegrade group and the retrograde group. The need for vasodilators or inotropes and weaning time were significantly lower in the retrograde group.
We conclude that retrograde cold blood cardioplegia provided myocardial protection and even early recovery of myocardium after CABG surgery.
Ebstein’s anomaly is considered one of the most common causes of congenital tricuspid regurgitation. It is usually associated with other anomalies such as atrial septal defects and accessory conduction pathways. The hemodynamic consequences and anesthetic implications for repair of Ebstein’s anomaly are challenging. Severe complicated cases of Ebstein’s anomaly usually manifest with significant tachyarrhythmia and hemodynamic derangement, leading to heart failure. This is a report of successful anesthetic management of a repair of Ebstein’s anomaly in a patient with coexisting Wolff–Parkinson–White syndrome.
Renal cell carcinoma (RCC) is the most common malignant tumor of the kidney. It is associated with inferior vena caval (IVC) extension in 4–10% of the patients. The Neves and Zincke classification of RCC tumors is based on their extension into the IVC, in which level I tumors extend renally, level II extend infrahepatically, level III extend retrohepatically, and level IV extend atrially. Although intravascular growth associated with RCC has no impact on survival when the tumors are treated surgically, the level and extension of the IVC tumor determines the surgical management plan. Transesophageal echocardiography (TEE) is used intraoperatively during resection of RCC in patients with level IV tumors because the tumor can embolize during surgical manipulation. In this case report, we present a case of a 50-year-old woman who was undergoing a radical nephrectomy a tumor thrombectomy to remove an RCC that was extending into the IVC and right atrium (RA). The surgery was complicated by embolization of the tumor to the pulmonary circulation intraoperatively. TEE enabled detection of tumor embolization few minutes before hemodynamic instability developed, this allowed faster management and contributed to a favorable patient outcome. We recommend continual TEE monitoring for all patients undergoing resection of RCC extending into the IVC and RA. This would help with earlier detection and management of complications, which will probably contribute to a decrease in the morbidity and mortality associated with the management of those high-risk patients.
Small infants especially in the lateral recumbent position may not tolerate changes in respiratory and cardiovascular parameters (mainly a decrease in PaO2, an increase in PaCO2, decrease in oxygen index (OI), increase in pulmonary arterial blood pressure, and increase in intracardiac shunt). The respiratory and cardiovascular changes may be even more pronounced during thoracic surgeries in these infants. So far, no study has compared two-lung ventilation (TLV) with single-lung ventilation (SLV) during video-assessed thoracoscopic surgery (VATS) in small infants with respect to respiratory and cardiovascular parameters. The aim of this study was to compare TLV with SLV during VATS in infants undergoing repair of congenital diaphragmatic hernia (CDH).
Forty patients comprising 22 boys and 18 girls with CDH requiring VATS were included in the study. The patients were randomly divided into two equal groups: group 1 (TLV) in which two-lung ventilation was used and group 2 (SLV) in which single-lung ventilation was used. Respiratory and hemodynamic parameters were assessed at various stages during the surgical procedure. Respiratory parameters included the following: arterial blood gases (pH, PaO2, and PaCO2), SpO2%, end-tidal CO2 (EtCO2), peak airway pressure (PAW), and OI. Hemodynamic parameters included the following: systolic blood pressure (BP), central venous pressure, pulmonary artery pressure, and shunt fraction (P/S).
With regard to the respiratory parameters, in group 1 (TLV) there was a statistically significant decrease in pH and an increase in OI in the lateral position with CO2 insufflation when compared with baseline values. In group 2 (SLV), there was a statistically significant decrease in pH and an increase in PaCO2/EtCO2/OI values in the lateral position with CO2 insufflation when compared with baseline values. With regard to hemodynamic parameters, in both groups there was a statistically significant increase in central venous pressure values in the lateral position with CO2 insufflation when compared with baseline values. Comparison of the studied respiratory and hemodynamic variables between the two groups revealed no statistically significant difference throughout the procedure. When SLV was used in group 2, it allowed better field visualization as reported by surgeons and there was a statistically significant decrease in operative time.
The use of SLV during thoracoscopic CDH repair allowed better visualization of the operative field, resulting in shorter operative time without any detrimental effect on hemodynamic and/or respiratory variables. SLV seems to be a feasible alternative during these procedures. Further studies are warranted to determine the safety of using this technique in children with CDH complicated by pulmonary hypertension.