Solomon Aronson

ASE/SCA guidelines for performing a comprehensive intraoperative multiplane transesophageal echocardiography examination: recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography.

Since the introduction of transesophageal echocardiography (TEE) to the operating room in the early 1980s,1-4 its effectiveness as a clinical monitor to assist in the hemodynamic management of patients during general anesthesia and its reliability to make intraoperative diagnoses during cardiac operations has been well established.5-26 In recognition of the increasing clinical applications and use of intraoperative TEE, the American Society of Echocardiography (ASE) established the Council for Intraoperative Echocardiography in 1993 to address issues related to the use of echocardiography in the operating room. In June 1997, the Council board decided to create a set of guidelines for performing a comprehensive TEE examination composed of a set of anatomically directed cross-sectional views. The Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography has endorsed these guidelines and standards of nomenclature for the various anatomically directed cross-sectional views of the comprehensive TEE examination. This document, therefore, is the collective result of an effort that represents the consensus view of both anesthesiologists and cardiologists who have extensive experience in intraoperative echocardiography. The writing group has several goals in mind in creating these guidelines. The first is to facilitate training in intraoperative TEE by providing a framework in which to develop the necessary knowledge and skills. The guidelines may also enhance quality improvement by providing a means to assess the technical quality and completeness of individual studies. More consistent acquisition and description of intraoperative echocardiographic data will facilitate communication between centers and provide a basis for multicenter investigations. In recognition of the increasing availability and advantages of digital image storage, the guidelines define a set of cross-sectional views and nomenclature that constitute a comprehensive intraoperative TEE examination that could be stored in a digital format. These guidelines will encourage industry to develop echocardiography systems that allow quick and easy acquisition, labeling, and storage of images in the operating room, as well as a simple mechanism for side-by-side comparison of views made at different times. ASE/SCA Guidelines for Performing a Comprehensive Intraoperative Multiplane Transesophageal Echocardiography Examination: Recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography

Association of preoperative risk factors with postoperative acute renal failure

We performed a systematic review of 28 studies that examined preoperative risk factors for postoperative renal failure. Included in the studies were 10,865 patients who underwent either vascular, cardiac, general, or biliary surgery. No two studies used the same criteria for acute renal failure. Variability in definitions of renal failure, lack of consistent criteria for establishing risk factors, and nonuniformity in the statistical methods employed result in a literature that is not adequate to support a comprehensive quantitative review. Of the 30 variables considered in the studies, preoperative renal risk factors, such as increased serum creatinine, increased blood urea nitrogen, and preoperative renal dysfunction were repeatedly found to predict postoperative renal dysfunction. The literature provides little quantitative information concerning the degree of risk associated with other factors. Cardiac risk factors, such as left ventricular dysfunction, were reported to be predictive of postoperative renal failure more consistently than was advanced age.

The effect of aprotinin on outcome after coronary-artery bypass grafting.

BACKGROUND Aprotinin has recently been associated with adverse outcomes in patients undergoing cardiac surgery. We reviewed our experience with this agent in patients undergoing cardiac surgery at Duke University Medical Center. METHODS We retrieved data on 10,275 consecutive patients undergoing surgical coronary revascularization at Duke between January 1, 1996, and December 31, 2005. We fit data to a logistic-regression model predicting each patients likelihood of receiving aprotinin on the basis of preoperative characteristics and to models predicting long-term survival (up to 10 years) and decline in renal function, as measured by increases in serum creatinine levels. RESULTS A total of 1343 patients (13.2%) received aprotinin, 6776 patients (66.8%) received aminocaproic acid, and 2029 patients (20.0%) received no antifibrinolytic therapy. All patients underwent coronary-artery bypass grafting, and 1181 patients (11.5%) underwent combined coronary-artery bypass grafting and valve surgery. In the risk-adjusted model, survival was worse among patients treated with aprotinin, with a main-effects hazard ratio for death of 1.32 (95% confidence interval [CI], 1.12 to 1.55) for the comparison with patients receiving no antifibrinolytic therapy (P=0.003) and 1.27 (95% CI, 1.10 to 1.46) for the comparison with patients receiving aminocaproic acid (P=0.004). As compared with the use of aminocaproic acid or no antifibrinolytic agent, aprotinin use was also associated with a larger risk-adjusted increase in the serum creatinine level (P<0.001) but not with a greater risk-adjusted incidence of dialysis (P=0.56). CONCLUSIONS Patients who received aprotinin had a higher mortality rate and larger increases in serum creatinine levels than those who received aminocaproic acid or no antifibrinolytic agent.

Risk Index for Perioperative Renal Dysfunction/Failure Critical Dependence on Pulse Pressure Hypertension

Background— An acute renal event after coronary bypass graft surgery is associated with high mortality and substantial additive cost. Methods and Results— This prospective and descriptive study of 4801 patients having coronary bypass graft surgery with cardiopulmonary bypass from November 1996 to June 2000 at 70 centers in 16 countries established associations between predictor variables and postoperative renal composite (renal dysfunction and/or renal failure) from a cohort of 2381 patients and developed a risk index assessed in a validation cohort of 2420 patients. Postoperative renal composite occurred in 231 patients (4.8%). Independent and significant risk factors were age >75 years (odds ratio [OR], 2.04; 95% confidence interval [CI], 1.23 to 3.37; P=0.006), preoperative congestive heart failure (OR, 2.38; CI, 1.55 to 3.64; P<0.001), prior myocardial infarction (OR, 1.75; CI, 1.08 to 2.83; P=0.023), preexisting renal disease (OR, 3.71; CI, 2.41 to 5.70; P<0.001), intraoperative multiple inotrope use (OR, 2.75; CI, 1.75 to 4.31; P<0.001), intraoperative intra-aortic balloon pump insertion (OR, 4.41; CI, 2.21 to 8.80; P<0.001), cardiopulmonary bypass >2 hours (OR, 1.78; CI, 1.15 to 2.74; P=0.01), and preoperative pulse pressure such that for every additional 20–mm Hg increment in pulse pressure >40 mm Hg, there was an OR of 1.49 (CI, 1.17 to 1.89; P=0.001). Patients with pulse pressure hypertension >80 mm Hg were 3 times more likely to die a renal-related death compared with those without (3.7% versus 1.1%). Conclusions— Beside established risk factors, pulse pressure is independently and significantly associated with increased renal composite.

The ECLIPSE trials: comparative studies of clevidipine to nitroglycerin, sodium nitroprusside, and nicardipine for acute hypertension treatment in cardiac surgery patients.

BACKGROUND: Acute hypertension during cardiac surgery can be difficult to manage and may adversely affect patient outcomes. Clevidipine is a novel, rapidly acting dihydropyridine L-type calcium channel blocker with an ultrashort half-life that decreases arterial blood pressure (BP). The Evaluation of CLevidipine In the Perioperative Treatment of Hypertension Assessing Safety Events trial (ECLIPSE) was performed to compare the safety and efficacy of clevidipine (CLV) with nitroglycerin (NTG), sodium nitroprusside (SNP), and nicardipine (NIC) in the treatment of perioperative acute hypertension in patients undergoing cardiac surgery. METHODS: We analyzed data from three prospective, randomized, open-label, parallel comparison studies of CLV to NTG or SNP perioperatively, or NIC postoperatively in patients undergoing cardiac surgery at 61 medical centers. Of the 1964 patients enrolled, 1512 met postrandomization inclusion criteria of requiring acute treatment of hypertension based on clinical criteria. The patients were randomized 1:1 for each of the three parallel comparator treatment groups. The primary outcome was the incidence of death, myocardial infarction, stroke or renal dysfunction at 30 days. Adequacy and precision of BP control was evaluated and is reported as a secondary outcome. RESULTS: There was no difference in the incidence of myocardial infarction, stroke or renal dysfunction for CLV-treated patients compared with the other treatment groups. There was no difference in mortality rates between the CLV, NTG or NIC groups. Mortality was significantly higher, though, for SNP-treated patients compared with CLV-treated patients (P = 0.04). CLV was more effective compared with NTG (P = 0.0006) or SNP (P = 0.003) in maintaining BP within the prespecified BP range. CLV was equivalent to NIC in keeping patients within a prespecified BP range; however, when BP range was narrowed, CLV was associated with fewer BP excursions beyond these BP limits compared with NIC. CONCLUSIONS: CLV is a safe and effective treatment for acute hypertension in patients undergoing cardiac surgery.

Perioperative renal dysfunction and cardiovascular anesthesia: Concerns and controversies

In patients with renal disease undergoing cardiovascular surgery, perioperative management continues to be a challenge. Traditional answers have turned into new questions with the introduction of new agents and the redesign of old techniques. For ARF prevention, early recognition of pending deleterious compensatory changes is critical. Theoretically, therapeutic intervention designed to prevent ischemic renal failure should be designed to preserve the balance between RBF and oxygen delivery on one hand and oxygen demand on the other. Maintenance of adequate cardiac output distribution to the kidney is determined by the relative ratio of renal artery vascular resistance to systemic vascular resistance. Indeed, it should not be surprising to learn that norepinephrine (despite its vasoconstricting effect) has been reported to have no deleterious renal effects in patients with low systemic vascular resistance. Until recently, strategies for the treatment of ARF have been directed to supportive care with dialysis (to allow tubular regeneration). Various therapeutic maneuvers have been introduced in an attempt to accelerate the recovery of glomerular filtration, including dialysis, nutritional regimens, and new pharmacologic agents. A recent small prospective trial of low-dose dopamine in the prophylaxis of ARF in patients undergoing abdominal aortic aneurysm repair showed no benefit in those patients receiving dopamine. Conversely, the effects of intravenous atrial natriuretic peptide in the treatment of patients with ARF appear to offer benefit in patients with oliguria. Among 121 patients with oliguric renal failure, 63% of those who received a 24-hour infusion of atrial natriuretic peptide required dialysis within 2 weeks compared with 87% who did not. Whether this effect will be borne out in the future remains to be determined. The administration of epidermal growth factor after induction of ischemic ARF in rats has been shown to enhance tubular regeneration and accelerate recovery of kidney function. Human growth factor administration has been shown to increase GFR 130% greater than baseline in patients with chronic renal failure, but no data for clinical ARF have been reported. In addition, there have been significant improvements in dialysis technology in the treatment of ARF. Modern dialysis uses bicarbonate as a buffer as opposed to acetate, which reduces cardiovascular instability, and has more precise regulation of volume removal. Dialysate profiles and temperatures improve hemodynamics and reduce intradialytic hypotension. Techniques of hemodialysis without anticoagulation have reduced bleeding complications. Finally, dialysis membranes activate neutrophils and complement less with the biocompatible membranes used today that reduce recovery time and dialysis treatment. Evidence indicates that activation of complement and neutrophils by older dialysis membranes caused a greater incidence of hypotension, adding to ischemic renal injury. It remains to be determined whether early and frequent dialysis with biocompatible membranes, as well as other therapeutic interventions, will increase the survival of patients with perioperative ARF.

Does anesthetic technique make a difference? Augmentation of systolic blood pressure during carotid endarterectomy: effects of phenylephrine versus light anesthesia and of isoflurane versus halothane on the incidence of myocardial ischemia

Whether anesthetic technique affected the incidence of myocardial ischemia in 60 patients undergoing carotid endarterectomy was investigated. The patients were randomly assigned to receive halothane or isoflurnne (with nitrous oxide) either nt a low concentration alone or at a higher concentration with phenylephrine added to support blood pressure. Blood pressure wns maintained within 20% of each patients average ward systolic pressure. Seven leads of electrocardiograms (ECC) and echocardiograms were analyzed for segmental wall motion. The echocardiograms were analyzed using standard formulae for end-systolic meridional wall stress (SWS) and rntecorrected velocity of fiber shortening (Vcfc). Because of the nature of these calculations, only echocardiograms with normal regional wall motion could be accurately analyzed. The patients had postoperative ECG and creatinine phosphokinase (CPK)isoenzyme determinations and regularly scheduled clinical examinations to detect perioperntive myocardial infarction and neurologic deficits. Although blood pressures were similar, the patients who received a higher concentration of anesthetic plus phenylephrine had a higher wall stress, regardless of the choice of anesthetic agent. All four techniques allowed provision of the same stump pressures (the marker surgeons used for adequacy of collateral carotid flow). No difference could be found in wall stress or incidence of myocardial ischemia between isoflurane and halothane. The patients who received phenylephrine had a threefold greater incidence of myocardial ischemia than did the patients who had light anesthesia to maintain similar systolic blood pressures and stump pressures. The groups were demographically and hemodynamicnlly similar; in particular, the heart rates were not different. Increased wall stress in anesthetized patients is associated with an increased incidence of myocardial ischemia as evidenced by new segmental wall motion and wall thickening abnormalities (SWMA).

Isolated systolic hypertension is associated with adverse outcomes from coronary artery bypass grafting surgery.

Isolated systolic blood pressure has not been sufficiently studied in the perioperative setting and may contribute to morbidity and mortality after coronary artery bypass grafting (CABG) surgery. Our objective was to determine the prevalence of isolated systolic hypertension among patients who had CABG surgery and to assess whether isolated systolic hypertension is associated with perioperative and postoperative in-hospital morbidity or mortality. Patients who underwent CABG were selected from a prospective epidemiological study involving 2417 patients in 24 medical centers. Patients were classified as having normal preoperative blood pressure, isolated systolic hypertension (systolic blood pressure >140 mm Hg), diastolic hypertension (diastolic blood pressure >90 mm Hg), or a combination of these. Demographic risk factors (age, sex, and ethnicity), clinical risk factors (diabetes mellitus, increased cholesterol, antihypertensive medications, history of congestive heart failure, myocardial infarction, hypertension, and neurological deficits), and behavioral risk factors (smoking and heavy drinking) were controlled for statistically. Adverse outcomes included left ventricular dysfunction, cerebral vascular dysfunction or events, renal insufficiency or failure, and all-cause mortality. Isolated systolic hypertension was found in 29.6% of patients. Unadjusted isolated systolic hypertension was associated with a 40% increased risk of adverse outcomes (odds ratio, 1.4; confidence interval, 1.1–1.7). After adjusting for other potential risk factors, the increased risk of adverse outcomes with isolated systolic hypertension was 30%. We conclude that isolated systolic hypertension is associated with a 40% increase in the likelihood of cardiovascular morbidity perioperatively in CABG patients. This increase remains present regardless of antihypertensive medications, anesthetic techniques, and other perioperative cardiovascular risk factors (e.g., age older than 60 yr or history of congestive heart failure, myocardial infarction, or diabetes).

Universal definition of perioperative bleeding in adult cardiac surgery

OBJECTIVES Perioperative bleeding is common among patients undergoing cardiac surgery; however, the definition of perioperative bleeding is variable and lacks standardization. We propose a universal definition for perioperative bleeding (UDPB) in adult cardiac surgery in an attempt to precisely describe and quantify bleeding and to facilitate future investigation into this difficult clinical problem. METHODS The multidisciplinary International Initiative on Haemostasis Management in Cardiac Surgery identified a common definition of perioperative bleeding as an unmet need. The functionality and usefulness of the UDPB for clinical research was then tested using a large single-center, nonselected, cardiac surgical database. RESULTS A multistaged definition for perioperative bleeding was created based on easily measured clinical end points, including total blood loss from chest tubes within 12 hours, allogeneic blood products transfused, surgical reexploration including cardiac tamponade, delayed sternal closure, and the need for salvage treatment. Depending on these components, bleeding is graded as insignificant, mild, moderate, severe, or massive. When applied to an established cardiac surgery dataset, the UDPB provided insight into the incidence and outcome of bleeding after cardiac surgery. CONCLUSIONS The proposed UDPB in adult cardiac surgery provides a precise classification of bleeding that is useful in everyday practice as well as in clinical research. Once fully validated, the UDPB may be useful as an institutional quality measure and serve as an important end point in future cardiac surgical research.

Clevidipine effectively and rapidly controls blood pressure preoperatively in cardiac surgery patients: the results of the randomized, placebo-controlled efficacy study of clevidipine assessing its preoperative antihypertensive effect in cardiac surgery-1.

BACKGROUND:Clevidipine is an ultrashort-acting, third-generation IV dihydropyridine calcium channel blocker that exerts rapid and titratable arterial blood pressure reduction, with fast termination of effect due to metabolism by blood and tissue esterases. As an arterial-selective vasodilator, clevidipine reduces peripheral vascular resistance directly, without dilating the venous capacitance bed. In this randomized, double-blind, placebo-controlled multicenter trial we evaluated the efficacy and tolerability of clevidipine in treating preoperative hypertension. METHODS:One-hundred-fifty-two patients scheduled for cardiac surgery with current or recent hypertension were randomized to receive clevidipine or placebo preoperatively. One-hundred-five patients met postrandomization entrance criteria (systolic blood pressure [SBP] ≥160 mm Hg after inserting an arterial catheter) for reduction by ≥15% from baseline in SBP. The patients thus received infusions of clevidipine (0.4–8.0 &mgr;g · kg−1 · min−1) or 20% lipid emulsion (placebo) for at least 30 min. Treatment failure was defined as failure to reduce SBP by ≥15% from baseline or discontinuance of drug for any reason. RESULTS:Patients treated with clevidipine demonstrated a 92.5% rate of treatment success and a significantly lower rate of treatment failure (7.5%, 4 of 53) than patients receiving placebo (82.7%, 43 of 52; P < 0.0001). Clevidipine achieved target blood pressures (SBP reduced by ≥15%) at a median of 6.0 min (95% confidence interval 6–8 min). A modest increase in heart rate from baseline occurred during clevidipine administration. Adverse events for each treatment group were similar. CONCLUSIONS:Clevidipine was effective in rapidly decreasing blood pressure preoperatively to targeted blood pressure levels and was well tolerated in patients scheduled for cardiac surgery.