Access-site complications and their management during transradial cardiac catheterization

Transradial access for cardiac catheterization is now widely accepted among the invasive cardiology community as a safe and viable approach with a markedly reduced incidence of major access-related complications compared with the transfemoral approach. As this access technique is now being used more commonly for cardiac catheterization, it is of paramount importance to be aware of its complications and to understand their prevention and management. Some of the common complications of transradial access include asymptomatic radial artery occlusion, nonocclusive radial artery injury and radial artery spasm. Among these complications, radial artery spasm is still a significant challenge. Symptomatic radial arterial occlusion, pseudoaneurysm and radial artery perforation are rarely reported complications of the transradial approach. Early identification of these rare complications and their immediate management is of vital importance. Arteriovenous fistula, minor nerve damage and complex regional pain syndrome are very rare but have been reported. Recently, granulomas have been reported to be associated with the use of a particular brand of hydrophilic sheaths during the procedure. Generally, access-site complications can be minimized by avoiding multiple punctures, selection of smaller sheaths, gentle catheter manipulation, adequate anticoagulation, use of appropriate compression devices and avoiding prolonged high-pressure compression. In addition, careful observation for any ominous signs such as pain, numbness and hematoma formation during and in the immediate postprocedure period is essential in the prevention of catastrophic hand ischemia.     

Access-site complications and their management during transradial cardiac catheterization

Transradial access for cardiac catheterization is now widely accepted among the invasive cardiology community as a safe and viable approach with a markedly reduced incidence of major access-related complications compared with the transfemoral approach. As this access technique is now being used more commonly for cardiac catheterization, it is of paramount importance to be aware of its complications and to understand their prevention and management. Some of the common complications of transradial access include asymptomatic radial artery occlusion, nonocclusive radial artery injury and radial artery spasm. Among these complications, radial artery spasm is still a significant challenge. Symptomatic radial arterial occlusion, pseudoaneurysm and radial artery perforation are rarely reported complications of the transradial approach. Early identification of these rare complications and their immediate management is of vital importance. Arteriovenous fistula, minor nerve damage and complex regional pain syndrome are very rare but have been reported. Recently, granulomas have been reported to be associated with the use of a particular brand of hydrophilic sheaths during the procedure. Generally, access-site complications can be minimized by avoiding multiple punctures, selection of smaller sheaths, gentle catheter manipulation, adequate anticoagulation, use of appropriate compression devices and avoiding prolonged high-pressure compression. In addition, careful observation for any ominous signs such as pain, numbness and hematoma formation during and in the immediate postprocedure period is essential in the prevention of catastrophic hand ischemia.     

Evaluation of a thoracic bioimpedance cardiac output monitor during cardiac catheterization

OBJECTIVE: To evaluate the accuracy and precision of an advanced thoracic bioimpedance cardiac output monitor by comparing it with conventional thermodilution. DESIGN: Prospective data collected from 47 patients undergoing routine cardiac catheterization. The new bioimpedance system differs from its predecessors in electrode system configuration, advanced signal processing, use of a modified Kubicek equation, and a reliable estimate of left ventricular ejection time from the time derivative bioimpedance signals. SETTING: A cardiac catheterization laboratory in a university affiliated teaching hospital. PATIENTS: A series of 47 relatively homogenous patients undergoing routine cardiac catheterization for suspected cardiac disease. MEASUREMENTS AND MAIN RESULTS: The data from the first 20 patients was used to determine optimal values for coefficients in the bioimpedance cardiac output equations. The coefficients found were used when the system was tested in the subsequent 27 patients. For the last 27 patients, a total of 80 simultaneous pairs of cardiac output measurements were made by conventional thermodilution and by thoracic bioimpedance. The mean difference between the two methods was -0.31 L/min and the standard deviation of the differences was (0.76 L/min). The correlation coefficient was r2 = .72 (p < .001). CONCLUSIONS: The correlation between conventional thermodilution and thoracic bioimpedance cardiac output estimates was good and the standard deviation of the differences was lower than that reported for commercially available devices. The system can be used in the cardiac catheterization lab for reliable and continuous noninvasive measurement of cardiac output.     

Neuroprotection during cardiac surgery

Cardiac surgery continues to be associated with significant adverse cerebral outcomes, ranging from stroke to cognitive decline. The underlying mechanism of the associated cerebral injury is incompletely understood but is believed to be primarily caused by cerebral embolism and hypoperfusion, exacerbated by ischemia/reperfusion injury. Extensive research has been undertaken in an attempt to minimize the incidence of perioperative cerebral injury, and both pharmacological and nonpharmacological strategies have been investigated. Although many agents demonstrated promise in preclinical studies, there is currently insufficient evidence from clinical trials to recommend the routine administration of any pharmacological agents for neuroprotection during cardiac surgery. The nonpharmacological strategies that can be recommended on the basis of evidence include transesophageal echocardiography and epiaortic ultrasound-guided assessment of the atheromatous ascending aorta with appropriate modification of cannulation, clamping or anastomotic technique and optimal temperature management. Large-scale randomized controlled trials are still required to address further the issues of optimal pH management, glycemic control, blood pressure management and hematocrit during cardiopulmonary bypass. Past, present and future directions in the field of neuroprotection in cardiac surgery will be discussed.     

Coronary angioscopy: From tissue imaging to molecular imaging

Angioscopy enables macroscopic pathological diagnosis of cardiovascular diseases from the inside. This imaging modality has been mainly directed to observation of coronary artery diseases. This method is now clinically used for classifying coronary plaques and thrombi, understanding mechanisms of acute coronary syndromes, evaluating percutaneous coronary interventions, evaluating plaque-stabilizing effects of drugs, and recently, for characterizing vulnerable plaques and vulnerable patients and accordingly for prediction of acute coronary syndromes. Fluorescence angioscopy was recently established and is now clinically used for molecular imaging of coronary plaques. Molecular and cellular imaging by this new imaging technology will contribute to more objective evaluation of coronary artery diseases.     

Percutaneous transluminal angioscopy during coronary intervention

To investigate the feasibility of angioscopic-guided percutaneous transluminal coronary angioplasty and to elucidate the mechanism of efficacy of coronary stenting for acute myocardial infarction, we performed coronary angioscopy in 102 patients with stable angina or acute myocardial infarction. Thrombi and intimal flaps were observed in most patients after coronary angioplasty. Large intimal splits were seen in one third of patients. Stents were inserted in 10 patients who were revealed to have a large flap or protruding split to the inner lumen. Thrombolytic agents were administered in 2 patients with large thrombi. Additional treatments were required in 32% of patients. No acute myocardial infarction or unstable angina occurred in patients during hospitalization. Thus, angioscopy of the coronary lumen enables clinicians to determine the most appropriate and least risky coronary intervention strategy. In patients with acute myocardial infarction, angioscopy revealed occlusive or protruding thrombi in 34 of 35 patients. The protruding thrombi disappeared after stenting. The frequency of large intimal flaps increased after predilatation with balloon, but these disappeared after stenting. The present angioscopic study demonstrates that the coronary stent compresses the occlusive or protruding thrombi and covers the ruptured thrombogenic plaque Consequently, smooth-surfaced and wide vessel lumen are obtained.     

Liver blood flow during cardiac surgery

OBJECTIVE: Impairment of liver blood flow and, therefore, potentially liver function, has important short-term consequences because of the liver's key metabolic importance and role in drug metabolism. The objective of this study was to quantify the effect of cardiac surgery on liver blood flow from before the induction of anaesthesia to 24 hours postoperatively. METHOD: Ten patients with no history of liver impairment, moderate or good left ventricular function, and undergoing routine hypothermic coronary artery bypass graft surgery, were entered into the study. Liver blood flow was determined by the clearance of indocyanine green (ICG), expressed as a percentage disappearance rate (PDR). RESULTS: The mean baseline percentage disappearence rate (PDR) of indocyanine green (ICG) was 19.84 +/- 4.47%/min. This increased marginally to 20.42 +/- 6.67%/min following the induction of anaesthesia, but after 15 min of cardiopulmonary bypass, the PDR fell to 13.51 +/- 3.69%/min; this was significantly lower than all other PDRs measured throughout the study. Prior to extubation, the PDR increased again to 20.01 +/- 3.72%/ min, and this level was maintained at 12 hours (PDR 20.32 +/- 3.53%min) and 24 hours (PDR 20.51 +/- 2.27%/min). CONCLUSION: The induction of anaesthesia and positive pressure ventilation do not affect liver blood flow. Cardiopulmonary bypass at 30 degrees C is associated with a significant reduction in liver blood flow, which returns to normal within 4-6 hours of surgery and remains normal for up to 24 hours after surgery.     

Pulse oximetry during cardiac catheterization in children with congenital heart disease

One hundred and five children with congenital heart disease were monitored by pulse oximetry during cardiac catheterization. Excellent correlation (r = 0.95) was found between oxygen saturation values obtained with pulse oximetry and those obtained from arterial blood in 133 data pairs. This correlation was described by the regression equation y = 0.91 x + 8.1. The correlation was also excellent in 47 data pairs with saturation values of less than 90% (r = 0.94, y = 0.93x + 6.0) from 36 cyanotic children. The clinical usefulness of pulse oximetry in the early recognition of decreased pulmonary blood flow or partial airway obstruction was demonstrated. Early diagnosis of changes in oxygenation was especially helpful in children with cyanotic congenital heart disease, in whom small changes in arterial oxygen tension may cause large changes in oxygen saturation.     

Monitored anesthesia care with a combination of ketamine and dexmedetomidine during cardiac catheterization

No specific regimen has been universally accepted as ideal for sedation during cardiac catheterization in infants and children. We evaluated a combination of ketamine and dexmedetomidine for sedation during cardiac catheterization in children with congenital heart disease. The study design included a retrospective analysis of data sheets and hospital records. The protocol for sedation was standardized and data collected prospectively for an ongoing quality assurance project. Heart rate, blood pressure, and oxygen saturation were recorded every 1 minute for the first 5 minutes and then at 5-minute intervals. The efficacy of sedation was judged by the need for supplemental ketamine doses. The study cohort included 16 infants and children undergoing either diagnostic or therapeutic cardiac catheterization. Sedation was initiated with a bolus dose of ketamine (2 mg/kg) and dexmedetomidine (1 microg/kg) administered over 3 minutes followed by a continuous infusion of dexmedetomidine (2 microg/kg per hour for the initial 30 minutes followed by 1 microg/kg per hour for the duration of the case). Supplemental analgesia/sedation was provided by ketamine (1 mg/kg) as needed. The baseline heart rate was 103 +/- 21 beats/minute. After the bolus dose of ketamine and dexmedetomidine, the heart rate increased by 7 +/- 5 beats/minute. The greatest increase was 15 beats/minute. The low heart rate after the bolus dose of ketamine/dexmedetomidine or during the subsequent dexmedetomidine infusion was 91 +/- 20 beats/minute (P < 0.001 compared with baseline) and the high heart rate was 110 +/- 25 beats/minute (P < 0.01 compared with baseline). In two patients, the dexmedetomidine infusion was decreased from 2 to 1 microg/kg per hour at 12 to 15 minutes instead of 30 minutes as a result of a decreased heart rate. No clinically significant changes in blood pressure or respiratory rate were noted. Two patients developed upper airway obstruction, which responded to repositioning of the airway. No apnea was noted. During the procedure, the PaCO2 varied from 37.5 to 48 mm Hg and was > or =45 mm Hg in seven patients. No patient responded to local infiltration of the groin and placement of the arterial and venous cannulae. Three patients required a supplemental dose of ketamine (1 mg/kg) during the procedure. In two of these patients, this was required before changing the cannulae. Our preliminary data suggest that a combination of ketamine and dexmedetomidine provides effective sedation for cardiac catheterization in infants and children without significant effects on cardiovascular or ventilatory function.     

Sleep during hospitalization and recovery after cardiac surgery

Sleep disturbance is common in patients undergoing cardiac surgery and has been recognized for more than 30 years. Research findings suggest that sleep disturbance is a multifactorial process that has many correlates in these patients and persists from the presurgical period throughout recovery. A growing body of literature suggests the importance of sleep for function and well-being of these patients. The research literature is synthesized and implications for future research and practice are discussed.     

The predictive value of lipid studies in patients undergoing cardiac catheterization and open heart surgery

All patients admitted for cardiac catheterization prior to possible coronary bypass surgery have a lipid profile ordered as part of their preadmission laboratory work. These studies, usually the first and only performed on the patient, include: high and low density lipoprotein-cholesterol, total cholesterol, triglyceride, and apolipoproteins A-I and B. This study was designed to determine the diagnostic significance and sensitivity of these tests based on a one-time determination as predictors of coronary artery disease. The three groups studied included those patients with surgically confirmed coronary artery disease (n = 247), aortic and/or mitral stenosis (n = 34), and normals, those free of disease (n = 30). The total population was 311 subjects, ranging in age from 20-85 years, which comprised 250 males and 61 postmenopausal females. The prevalence of the disease was 77% over the total population, with 238 of those with coronary artery disease going on to bypass surgery. Surgical results of cardiac catheterization were collected as percent occlusion. No correlations were found between lipoproteins and percent occlusion in the diseased group. Calculations of sensitivity and specificity for various lipid values suggested no clinical use for a one-time determination of these apo- and lipoproteins.     

Preparation for cardiac catheterization.

Cardiac catheterization is an invasive procedure often included in the medical evaluation of patients with ischemic heart disease. This article reviews one well-designed study that examines various approaches for preparing adults for a cardiac catheterization.