S100beta correlates with neurologic complications after aortic operation using circulatory arrest.

BACKGROUND: Astrocyte protein S100beta is a potential serum marker for neurologic injury. The goals of this study were to determine whether elevated serum S100beta correlates with neurologic complications in patients requiring hypothermic circulatory arrest (HCA) during thoracic aortic repair, and to determine the impact of retrograde cerebral perfusion (RCP) on S100beta release in this setting. METHODS: Thirty-nine consecutive patients underwent thoracic aortic repairs during HCA; RCP was used in 25 patients. Serum S100beta was measured preoperatively, after cardiopulmonary bypass, and 24 hours postoperatively. RESULTS: Neurologic complications occurred in 3 patients (8%). These patients had higher postbypass S100beta levels (7.17 +/- 1.01 microg/L) than those without neurologic complications (3.63 +/- 2.31 microg/L, p = 0.013). Patients with S100beta levels of 6.0 microg/L or more had a higher incidence of neurologic complications (3 of 7, 43%) compared with those who had levels less than 6.0 microg/L (0 of 30, p = 0.005). Retrograde cerebral perfusion did not affect S100beta release. CONCLUSIONS: Serum S100beta levels of 6.0 microg/L or higher after HCA correlates with postoperative neurologic complications. Using serum S100beta as a marker for brain injury, RCP does not provide improved cerebral protection over HCA alone.

Mortality and paraplegia after thoracoabdominal aortic aneurysm repair: a risk factor analysis.

BACKGROUND: Recent recommendations regarding thoracoabdominal aortic aneurysm (TAAA) management have emphasized individualized treatment based on balancing a patient's calculated risk of rupture with their anticipated risk of postoperative death or paraplegia. The purpose of this study was to enhance this risk-benefit decision by providing contemporary results and determining which preoperative risk factors currently predict mortality and paraplegia after TAAA surgery. METHODS: Risk factor analyses based on data regarding 1,220 consecutive patients undergoing TAAA repair from 1986 through 1998 were performed using multiple logistic regression with step-wise model selection. RESULTS: The 30-day mortality rate was 4.8% (58 of 1,220) and the incidence of paraplegia was 4.6% (56 of 1,206). For elective cases, predictors of operative mortality included renal insufficiency (p = 0.0001), increasing age (p = 0.0005), symptomatic aneurysms (p = 0.0059), and extent II aneurysms (p = 0.0054). Extent II aneurysms (p = 0.0023) and diabetes (p = 0.0402) were predictors of paraplegia. CONCLUSIONS: These risk models may assist in decisions regarding elective TAAA operations. For patients who are acceptable candidates, contemporary surgical management provides favorable results.

Anesthetic management of Takayasu's arteritis for extra-anatomic thoraco-abdominal aorto-aortic bypass: a case report.

Takayasu's arteritis, also known as Takayasu's syndrome, is a chronic inflammatory disease, which primarily affects large vessels including the aorta and its main branches. The anesthetic management for the patient presenting with Takayasu's arteritis is complicated by the multiple organ systems affected by the disease. A 59-year-old Chinese female with the diagnosis of Takayasu's arteritis presented with severe progressive occlusion of the thoracic and abdominal aorta and bilateral renal artery stenosis, necessitating an extra-anatomic aorto-aortic bypass and bilateral aorto-renal bypass. The patient tolerated the operative procedure without any untoward events. This case report discusses the pathophysiology of Takayasu's arteritis and the anesthetic management of aortic surgery specific to this particular disease process.

Nitric oxide-synthesizing perivascular nerves in the rat middle cerebral artery.

Although perivascular nerves containing nitric oxide synthase (NOS) have been anatomically described for rat cerebral arteries, a dilator function for these nerves has eluded investigators when using isolated vessels. Rat middle cerebral arteries (MCAs) were isolated, pressurized, and electrically stimulated. The resting diameter of the MCAs after pressurization was 233 +/- 4 microns (n = 17) in one study. The MCAs showed a frequency-dependent dilation when stimulated. Maximum dilation (25-30% increase in diameter) occurred at a frequency of 8-16 Hz. Removal of endothelium or glibenclamide (10(-5) M), a blocker of ATP-sensitive potassium channels, had no effect on the dilations. The dilations were completely blocked with NG-nitro-L-arginine methyl ester (L-NAME) (10(-5) M), a general NOS inhibitor, and cold storage (24 h). The inhibition by L-NAME could be reversed by the addition of 10(-8) M L-arginine, the active precursor of NOS. Furthermore, 7-nitroindazole (10(-4) M), an inhibitor specific for the neuronal isoform of NOS, reduced the dilations by 43% (P < 0.05). Transections of nerve bundles originating from the sphenopalatine ganglia at the ethmoidal foramen blocked the dilations produced by electrical stimulations. We conclude that rat cerebral arteries have functionally intact perivascular nerves that dilate by releasing nitric oxide.

Central venous catheters coated with minocycline and rifampin for the prevention of catheter-related colonization and bloodstream infections. A randomized, double-blind trial. The Texas Medical Center Catheter Study Group.

BACKGROUND: Central venous catheters are a principal source of nosocomial bloodstream infections, which are difficult to control. OBJECTIVE: To determine the efficacy of catheters coated with minocycline and rifampin in preventing catheter-related colonization and bloodstream infections. DESIGN: Multicenter, randomized clinical trial. SETTING: Five university-based medical centers. PATIENTS: 281 hospitalized patients who required 298 triple-lumen, polyurethane venous catheters. INTERVENTION: 147 catheters were pretreated with tridodecylmethyl-ammonium chloride and coated with minocycline and rifampin. Untreated, uncoated catheters (n = 151) were used as controls. MEASUREMENTS: Quantitative catheter cultures, blood cultures, and molecular typing of organisms to determine catheter-related colonization and bloodstream infections. RESULTS: The group with coated catheters and the group with uncoated catheters were similar with respect to age, sex, underlying diseases, degree of immunosuppression, therapeutic interventions, and risk factors for catheter infections. Colonization occurred in 36 (26%) uncoated catheters and 11 (8%) coated catheters (P < 0.001). Catheter-related bloodstream infection developed in 7 patients (5%) with uncoated catheters and no patients with coated catheters (P < 0.01). Multivariate logistic regression analysis showed that coating catheters with minocycline and rifampin was an independent protective factor against catheter-related colonization (P < 0.05). No adverse effects related to the coated catheters or antimicrobial resistance were seen. An estimate showed that the use of coated catheters could save costs. CONCLUSIONS: Central venous catheters coated with minocycline and rifampin can significantly reduce the risk for catheter-related colonization and bloodstream infections. The use of these catheters may save costs.

An initial multicenter, randomized controlled trial on the safety and efficacy of acadesine in patients undergoing coronary artery bypass graft surgery. SPI Research Group.

Acadesine (5-amino-4-imidazole carboxamide riboside) is a purine nucleoside analog that has been shown in animals to reduce myocardial ischemic injury by selectively increasing the availability of adenosine in ischemic tissues. Because patients undergoing coronary artery bypass graft (CABG) surgery are especially vulnerable to developing myocardial ischemia, we investigated whether perioperative use of this adenosine-regulating drug with potential anti-ischemic properties could modify the incidence and severity of perioperative myocardial ischemia. The goals of this study were to evaluate safety and the effects of acadesine on myocardial ischemia, left ventricular function, and, secondarily, on adverse clinical outcomes (myocardial infarction, heart failure, life-threatening dysrhythmias, and death) in patients undergoing CABG surgery. One hundred sixteen patients were randomized to receive one of three continuous intravenous dosing regimens (placebo [control] or one of two doses of acadesine [high- and low-dose infusion]) in double-blind fashion intraoperatively and in the early postoperative period (total infusion time was 7 h). Multidose cold crystalloid cardioplegia (each containing either acadesine or placebo) was used for myocardial protection. All were monitored for potentially drug-related adverse events and the presence of myocardial ischemia was assessed by continuous Holter electrocardiography (ECG) and transesophageal echocardiography (TEE). All patients received standardized anesthetic, surgical, and hemodynamic management during the intraoperative period. All research data (ECG, TEE, outcome data) were evaluated at the coordinating center (San Francisco) in blinded fashion to ensure that uniform data analysis criteria were employed. The administration of acadesine was safe: mild increases in plasma uric acid (a metabolite of acadesine) occurred only in patients receiving high doses (mean increase 1.6 +/- 0.2 mg/dL) and were without clinical sequelae. Before drug administration in the preoperative period (baseline), the incidence and severity of ECG ischemia did not differ among the three groups (placebo = 18%; low-dose = 14%; high-dose = 14%). During prebypass, the incidence of ECG ischemia was similar in all three groups (0%, 3%, 3%, respectively). The incidence of TEE ischemia was numerically lower in the two acadesine groups (high-dose = 6%, low-dose = 15%) than in the control group (19%), but this was not statistically significant (P = 0.22). During postbypass, the incidence of ECG ischemia was 11% in the high-dose group, 22% in the low-dose group, and 18% in the control group (P = 0.42), and TEE ischemia was similar in incidence in all groups (placebo = 29%; low dose = 27%; high-dose = 24%) (P = 0.86).(ABSTRACT TRUNCATED AT 400 WORDS)

Results of coronary surgery after failed elective coronary angioplasty in patients with prior coronary surgery.

The results of coronary artery bypass surgery after failed elective coronary angioplasty in patients who have undergone prior coronary surgery are unknown. Coronary angioplasty may be performed to relieve angina after surgery either to the native coronary vessels or to grafts. Failure of attempted coronary angioplasty may mandate repeat coronary surgery, often in the setting of acute ischemia. From 1980 to 1989, 1,263 patients with prior coronary bypass surgery underwent angioplasty; of these patients, 46 (3.6%) underwent reoperation for failed angioplasty during the same hospital stay. Of the 46 patients who underwent reoperation, 33 had and 13 did not have acute ischemia. In the group with ischemia, 3 patients (9.1%) died and 14 (42.4%) died or had a Q wave myocardial infarction in the hospital compared with no deaths (p = NS) and no deaths or Q wave myocardial infarction (p = 0.005) in the group without ischemia. At 3 years, the actuarial survival rate was 88 +/- 6% in the group with ischemia, whereas there were no deaths in the group without ischemia (p = NS), and freedom from death or myocardial infarction was 51 +/- 10% in the group with ischemia, versus no events in the group without ischemia (p = 0.006). In most patients with prior coronary bypass surgery, coronary angioplasty was performed without the need for repeat coronary bypass surgery. Should coronary angioplasty fail, reoperation in patients without acute ischemia can be performed with overall patient survival comparable to that of elective reoperative coronary bypass without coronary angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Contamination reduction during central venous catheterization.

This study examined a simple technique for reducing contamination during catheterization of the internal jugular vein. Sixty patients were assigned randomly to receive either a traditional iodophor skin cleansing or an alcohol cleansing, followed by application of an iodophor-impregnated sterile film. In the cleansed with iodophor alone group, 83% of the anesthesiologists' glove tips were contaminated, and 13% of the catheter tips were contaminated. In contrast, in the group in which the sterile film was employed, contamination of gloves and catheters was virtually eliminated.

Severe preeclampsia: hemodynamic effects of lumbar epidural anesthesia.

The hemodynamic effects of lumbar epidural anesthesia (LEA) were evaluated in 11 patients with severe preeclampsia. All patients were receiving magnesium sulfate upon entry into the study. Hemodynamic measurements were obtained before and after LEA, at delivery, and 2 hr postpartum. Lumbar epidural anesthesia significantly reduced mean arterial pressure from 121.4 mm Hg to 97.7 mm Hg, without altering cardiac index, pulmonary vascular resistance, central venous pressure (CVP), or pulmonary capillary wedge pressure (PCWP). There was a slight but statistically insignificant decrease in systemic vascular resistance from 1078 to 900.7 dynes X sec X cm-5. Cardiac index and left ventricular stroke work index were elevated in these patients, suggesting hyperdynamic left ventricular function. There was poor correlation between PCWP and CVP in several patients. We conclude that LEA may be used safely in severe preeclamptic patients and that pulmonary arterial catheters may help guide appropriate therapy in preeclamptic patients with cardiac failure or oliguria refractory to modest fluid challenges.

Effect of enflurane, isoflurane, and halothane on pacing stimulation thresholds in man.

Volatile anesthetic agents are often used in patients who require temporary epicardial pacing after cardiopulmonary bypass (CPB). However, the effect of anesthetic agents on energy stimulation thresholds is unknown. After CPB, 24 patients under diazepam-narcotic-pancuronium anesthesia ventilated with an FIO2 = 1.0 received equipotent concentrations of either enflurane, isoflurane, or halothane. Using temporary epicardial electrodes, energy stimulation thresholds were calculated using the data derived from a pacing systems analyzer. Volatile anesthetics do not change energy stimulation thresholds from those already present under diazepam-narcotic-pancuronium anesthesia.

Surgical management of acute myocardial ischemia following percutaneous transluminal coronary angioplasty. Role of the intra-aortic balloon pump.

Acute myocardial ischemia is a serious complication of percutaneous transluminal coronary angioplasty, often requiring emergency myocardial revascularization. Since our initial report of 17 such patients, we have encountered an additional 32 patients requiring emergency myocardial revascularization since September, 1981. The indication for emergency myocardial revascularization was ischemic chest pain in all 32 patients. Percutaneous transluminal coronary angioplasty resulted in injury to the right coronary artery in 11 patients, the left anterior descending artery in 19 patients, and the left main artery in two patients. The onset of ischemia was immediate in 26 patients but delayed up to 22 hours in six patients. Chest pain was associated with ST-segment elevation in 21 patients, hypotension in 7 patients, and cardiac arrest in 6 patients. Immediate intra-aortic balloon pumping was instituted in the angioplasty suite in 16 patients. The mean time from onset of ischemia to completed revascularization was 156 minutes with a mean of 1.6 grafts performed per patient. Seventeen patients (53%) had enzyme evidence of myocardial infarction postoperatively, with a significantly higher (p less than 0.01) incidence of myocardial infarction in those patients with preoperative ST elevation (76% versus 9%). In the 21 patients with ST-segment elevation, the incidence of Q wave infarction was 20% (3/15) with balloon pumping and 50% (3/6) without balloon pumping. Complications associated with intra-aortic balloon pumping occurred in one patient (6%). There were no hospital or late deaths with follow-up extending 16 months. The spectrum of injury resulting from percutaneous transluminal coronary angioplasty extends from chest pain alone to severe transmural ischemia with hypotension or cardiac arrest. Presentation may be immediate or delayed. Urgent emergency myocardial revascularization remains the accepted therapy for this complication. Immediate preoperative intra-aortic balloon pumping is a useful adjunct to emergency myocardial revascularization in the group of patients with acute ischemia and ST-segment elevation.

Concomitant carotid and coronary artery reconstruction.

Data are presented on 68 patients who underwent concomitant carotid endarterectomy (CE) and coronary artery bypass surgery (CAB) at Emory University Hospital from January 1974 to February 1981. This group is then compared with a randomly selected, matched population without known carotid disease who underwent CAB alone. Asymptomatic bruit was the reason for investigation in 40 patients (59%); another 23 patients (34%) experienced transient cerebral ischemic attacks (TIAs); and five patients (7%) had TIA and prior stroke. Carotid stenoses (>75% luminal narrowing) were demonstrated as follows: isolated left, 24 patients; isolated right, 27 patients; and bilateral lesions, 16 patients. One patient had innominate artery stenosis. Associated total occlusion of one or both vertebral arteries was demonstrated in six patients. Ninety-seven per cent of patients had disabling angina pectoris prior to operation; the angina was unstable in 57%, 15% had congestive heart failure, and 54% had had at least one prior myocardial infarction (MI). Single-vessel coronary disease was present in 12.5% of patients, double in 37.5%, triple in 41.1%, and left main stenosis in 9%; 43% of patients had abnormal ventricular contractility. CE was performed on 67 patients (36 left and 31 right); aortocarotid bypass was performed on one. The CE procedures were performed immediately prior to the sternotomy for CAB under the same anesthesia. CAB consisted of single bypass in eight patients (11.8%); double in 16 patients (23.5%); triple in 22 patients (32.4%); and quadruple or more in 22 patients (32.4%) (mean = 2.9 grafts per patient). There was no hospital mortality. Perioperative MI occurred in 2.0% and stroke with residual deficit in 1.3%. Cumulative survival is 98.5% at two years. Sixty-three patients (92%) reported improvement or elimination of anginal symptoms after operation. Rehospitalization for stroke was necessary in 3.7% patients. Postoperative activity levels are; self-care only, 3.9%; normal daily activity only, 17.6%; moderate exercise capability, 45%; and vigorous exercise capability, 33%. Comparison was made with a group of 84 randomly selected patients who underwent CAB alone during the same time interval. Data revealed no significant difference between the groups regarding sex, angina subset, ventricular function, coronary anatomy, vessels grafted, perioperative stroke or MI, mortality, or postoperative activity capability. Older age (59.8 vs. 55.6, p < 0.01) and less complete coronary revascularization possible (66 vs. 84%, p < 0.05) in the CECAB group were the only significant differences. Carotid stenosis co-existing in patients requiring CAB should be concomitantly corrected with the same risk and results expected from CAB alone.