Anesthetic Considerations for Mediastinal Staging Procedures for Lung Cancer.

Tumor staging is critical for the treatment of lung malignancies. Invasive techniques of lung tumor staging can be accomplished via mediastinoscopy, endobronchial ultrasound, and video-assisted thoracoscopy. Anesthesiologists taking care of patients undergoing mediastinal staging procedures might face different challenges. In this narrative review, the authors summarize the literature on the anesthetic considerations for mediastinal staging procedures.

Accumulation of a tetrahydroisoquinoline in phenylketonuria.

3',4'-Deoxynorlaudanosolinecarboxylic acid (DNLCA), a tetrahydroisoquinoline derived from dopamine and phenylpyruvic acid, has been detected by computerized mass fragmentography in urine of phenylketonuric children and in urine and brain of rats with experimentally induced hyperphenylalaninemia. Levels of DNLCA in brain of treated animals were more than tenfold higher than controls, and the excess tetrahydroisoquinoline appeared to accumulate in the cerebellum and cortex. DNLCA is a noncompetitive inhibitor of dopamine beta-hydroxylase (inhibition constant, Ki, = 0.42 mM) and is taken up by the brain.

Activation of cultured vascular endothelial cells by antiphospholipid antibodies.

Circulating antiphospholipid antibodies (aPL) are associated with a syndrome of thrombosis, recurrent fetal loss, and thrombocytopenia. We have demonstrated the activation of cultured human umbilical vein endothelial cells (HUVEC) by IgG from patients with anticardiolipin antibodies (aCL). Incubation of HUVEC for 4 h with purified IgG (100 micrograms/ml) from patients with high-titer aCL induced a 2.3-fold increase in monocyte adhesion over that seen in HUVEC incubated with IgG's from normal subjects. The effect of aCL was not attributable to LPS contamination, Fc receptors, or immune complexes. Monocyte adhesion was not induced when the aCL were added in serum-free media but was restored by the addition of purified beta 2GP1, previously described as a necessary cofactor for aCL reactivity. Purified rabbit polyclonal IgG raised against beta 2GP1 also induced monocyte adhesion when incubated with HUVEC. Preadsorption of patient serum with cardiolipin reduced monocyte adhesion by 60%. Immunofluorescent microscopy demonstrated that endothelial cells incubated with patient IgG expressed cell adhesion molecules, including E-selectin, vascular cell adhesion molecule-1, and intracellular adhesion molecule-1. These data support the hypothesis that aPL activate vascular endothelial cells, thereby leading to a pro-thrombotic state.

Randomized comparison of ticlopidine and clopidogrel after intracoronary stent implantation in a broad patient population.

BACKGROUND: Although clopidogrel is used to prevent subacute stent thrombosis, its safety and efficacy have not been compared with ticlopidine in a randomized manner in the United States. METHODS AND RESULTS: Patients with successful intracoronary stent implantation were randomly assigned to therapy with ticlopidine or clopidogrel. Loading doses were administered immediately after the procedure, and the drugs were prescribed for 2 weeks. One thousand sixteen patients were enrolled: 522 patients were randomly assigned to ticlopidine therapy and 494 to clopidogrel. High-risk characteristics included recent myocardial infarction in 41.4% of the cases, angiographically evident thrombus in 20.9%, and abrupt or threatened closure in 3.64%. An intravenous glycoprotein IIb/IIIa inhibitor was used in 48.2% of the cases, and thrombocytopenia occurred in 1.43% of these patients. Failure to complete 2 weeks of therapy occurred in 3.64% of the patients treated with ticlopidine and in 1.62% of the patients treated with clopidogrel (P=0.043). Within 30 days, thrombosis of the stent occurred in 1.92% of the patients in the ticlopidine group and in 2.02% of the clopidogrel group (P=0.901). A major adverse cardiac event occurred in 4.60% of patients receiving ticlopidine and in 3.85% of patients receiving clopidogrel (P=0.551). CONCLUSIONS: Clopidogrel is better tolerated than ticlopidine during a 2-week regimen after intracoronary stent implantation. Combining either thienopyridine with an intravenous platelet IIb/IIIa inhibitor appears to be safe. When applied to a broad spectrum of patients receiving stent implantation, clopidogrel confers similar protection as ticlopidine against subacute stent thrombosis and major adverse cardiac events.

Usefulness of dobutamine stress echocardiography for the prospective identification of the physiologic significance of coronary narrowings of moderate severity in patients undergoing evaluation for percutaneous transluminal coronary angioplasty.

Dobutamine stress echocardiography (DSE) was performed after coronary angiography to evaluate the need to perform percutaneous transluminal coronary angioplasty (PTCA) for 46 stenoses of moderate severity (50% to 80%) in 46 patients. Patients were divided into 2 groups according to the DSE results in the distribution of the coronary artery with the lesion of moderate severity: group I (n = 32) were those without inducible myocardial ischemia; PTCA was not performed. Group II (n = 14) were those who exhibited myocardial ischemia; PTCA was performed in 12. The 2 groups were comparable in terms of clinical characteristics. Follow-up DSE was performed < or = 48 hours after PTCA, at 3 months, and 6 to 12 months after the first DSE. In group I at 3 months, DSE results were still negative in the distribution of the vessel with the moderately severe lesion in 24 patients; only 1 patient had a positive result, and 8 patients who refused DSE remained clinically stable. At 6 to 12 months (mean 7 +/- 2), 26 patients had negative study results; 3 patients who refused follow-up DSE remained clinically stable. In group II, 12 of 14 patients with inducible ischemia on the initial DSE underwent PTCA. Early follow-up DSE (< or = 48 hours) was negative in 7, and 4 had persistent inducible wall motion abnormalities in the myocardium subtended by the coronary artery in which the PTCA had been performed; 1 study was not performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of methods for local delivery of tissue factor pathway inhibitor to balloon-injured arteries in rabbits.

BACKGROUND: Prolonged intravenous infusions of recombinant tissue factor pathway inhibitor (rTFPI) have been shown to attenuate markedly neointimal formation and stenosis after balloon-induced injury to the carotid arteries in minipigs. DESIGN: Because local delivery of rTFPI to the injury site would be clinically advantageous, we designed this study to compare the local delivery and retention of rTFPI in balloon-injured arteries using three catheter-based systems. METHODS: Similar amounts (range 3-4.5 mg) of a mixture of 125I-labeled and unlabeled rTFPI were delivered by either passive diffusion at moderate pressure (5 x 10(5) Pa with the LocalMed InfusaSleeve, or 4 x 10(5) Pa with the SciMed Dispatch device), or facilitated diffusion combining lower pressure (2 x 10(5) Pa) and electrical current (3.5 mA/cm2; e-MED, iontophoresis) to balloon-injured carotid arteries in anesthetized rabbits. RESULTS: Comparable amounts of rTFPI were retained on the injured vessels immediately after delivery (t = 0) with the LocalMed (628 +/- 68 micrograms/g per cm2, n = 4), SciMed (522 +/- 167 micrograms/g per cm2, n = 4), and e-MED (497 +/- 142 micrograms/g per cm2, n = 4) catheters (NS). However, rTFPI was decreased by 37% after 24 h compared with t = 0 (P < 0.02) in the e-MED group, but was increased 1.5-fold (P = 0.02) and 1.3-fold in the SciMed and LocalMed groups, respectively, presumably because of redistribution of rTFPI from remote endothelial or perivascular sites. Retention of rTFPI was six to nine times higher for injured compared with non-injured arteries, and persisted for at least 48 h after delivery with the LocalMed catheter. CONCLUSIONS: Sustained, marked retention of rTFPI delivered locally at the site of balloon-induced arterial injury appears to result from catheter-based systems that use passive diffusion at moderate pressure.

Myocardial protection during percutaneous transluminal coronary angioplasty.

Coronary angioplasty results in transient coronary artery occlusion. This article reviews with systemic and regional methods aimed at preventing the electrophysiologic and hemodynamic consequences of regional myocardial ischemia.

Pseudoaneurysm following successful excimer laser coronary angioplasty of a restenotic left internal mammary artery graft ostial lesion.

Although significant left internal mammary artery graft ostial stenosis is extremely rare, the clinical importance can be profound. In this report we describe a case in which a restenotic left internal mammary artery graft ostial lesion was successfully opened with excimer laser coronary angioplasty. A resulting pseudoaneurysm spontaneously closed after conservative therapy.

[Nutrition acute pancreatitis]. / Nutrición en pancreatitis aguda.

Acute pancreatitis is a common and potentially severe disease where nutritional support does affect its development in a way it may be considered a treatment in severe cases. These include around 20% of patients and present mortality rates of 8%-39%. In mild acute pancreatitis patients are prescribed nil per os at admission and advance diet in a progressive manner the following days. Although early introduction of diet has proven to shorten the length of stay, it is still not clear when and how to introduce diet. Severe disease is a hypercatabolic situation which often appears in already malnourished patients. Early enteral nutrition has shown a significative benefit over parenteral nutrition in terms of infection rates, hyperglycemia and mortality rates. This benefit may be related to a decrease in bacterial intestinal translocation. Nasoyeyunal tube feeding is the preferred site, but there are trials supporting nasogastric tubes, a more feasible election. The following lines offer an up to date review of nutritional management in acute pancreatitis, trying to answer in a clear and practical way to the most frequent problems arising in the day to day management of this disease.

Rotablator plus stent therapy (rotastent).

Over 400,000 percutaneous transluminal coronary angioplasties (PTCAs) are currently performed annually in the United States. Approximately 10% of these procedures include rotational atherectomy, although the national average rate of stent placements continues to increase in some centers to as high as 75%. The combination of rotational atherectomy and intra-coronary stent placement is between 2% and 7.5% of interventional procedures per year in the United States. This article reviews the existing literature on rotational atherectomy and stent implantation for complex lesions and describes the upcoming prospective, multicenter randomized Stent Implantation, Postrotational Atherectomy (SPORT) trial.

Stent thrombosis in a patient receiving chemotherapy.

Intravascular stents are successfully used during coronary revascularization. Subacute stent thrombosis is a rare complication, associated with a 40-60% risk of myocardial infarction, and occurs 5-10 days after implantation. We describe a case of late stent thrombosis potentially due to delayed endothelialization from cancer chemotherapy.

Acute myocardial infarction caused by a myocardial bridge treated with intracoronary stenting.

The clinical significance of myocardial bridges (MBs) is variable, and most patients are asymptomatic. However, angina, myocardial infarction, and sudden death have been reported in association with MBs. Here we describe the use of intracoronary stenting for the treatment of a patient with an anterior myocardial infarction due to an MB.

Modified heparin-bonded catheter for cannulation of the coronary sinus from the femoral vein.

Serial sampling from the coronary sinus is an attractive technique for drawing blood samples to be used in the characterization of procoagulant activity during coronary interventions. We have developed a modified Simmons catheter for rapid cannulation of the coronary sinus from the femoral approach. The catheter design incorporates heparin bonding and distal side-holes to minimize blood sampling artifacts. Coronary sinus cannulation was performed via the femoral approach in 186 patients by use of a multipurpose catheter (n = 8), an unmodified Simmons I or II catheter (n = 64), or the modified Simmons catheter (n = 114). The coronary sinus was cannulated successfully with the modified Simmons catheter in 97% of patients; the success rate with the unmodified Simmons II catheter was 87% (P = 0.02). The modified Simmons catheter represents an improved technique for cannulation of the coronary sinus from the femoral vein.

Association of heparin-resistant thrombin activity with acute ischemic complications of coronary interventions.

BACKGROUND: Acute thrombosis is thought to contribute to abrupt coronary occlusion during percutaneous coronary revascularization despite the administration of heparin and aspirin. This study was designed to detect the presence of heparin-resistant thrombin activity and to define its relationship to the acute ischemic complications of coronary interventions. METHODS AND RESULTS: Plasma levels of fibrinopeptide A (FPA) and prothrombin fragment 1.2 (F1.2), markers of thrombin and factor Xa activity, respectively, were measured in the coronary sinus with heparin-bonded catheters in 58 patients undergoing coronary interventions. Activated coagulation times were maintained > 300 seconds by the Hemochron method. Mean FPA levels decreased significantly, from 7.0 +/- 0.9 nmol/L before the procedure to 5.2 +/- 0.5 nmol/L after the heparin bolus and to 2.9 +/- 0.2 nmol/L after the procedure (P = .0001). In 26 patients (45%), FPA levels remained above the threshold for suppression angioplasty of thrombin activity determined during angiography in 7 patients without coronary artery disease (> 3.0 nmol/L). FPA concentrations after coronary interventions were increased in patients with intracoronary thrombus (P = .01), abrupt coronary occlusion (P = .06), postprocedural non-Q-wave myocardial infarction (P = .04), and clinically unsuccessful procedures (P = .04). F1.2 levels were relatively low before the procedures and did not change significantly. CONCLUSIONS: Heparin administration suppresses thrombin activity in most but not all patients undergoing coronary interventions. Heparin-resistant thrombin activity is associated with angiographic evidence of intracoronary thrombus and ischemic complications of coronary interventions.

Safety and efficacy of suture-mediated closure after percutaneous coronary interventions.

Percutaneous coronary interventions (PCI) performed with concomitant use of heparin and platelet inhibitors are safe procedures with reported vascular complication rates of approximately 6.1%. EPILOG investigators demonstrated that utilizing a low-dose heparin regimen with abciximab, along with early sheath removal, vascular access-related bleeding was significantly lower than that reported in EPIC. Recently, a suture-mediated closure (SMC) device has been reported to be safe, appears effective, and may improve patient comfort by allowing early ambulation. We conducted a retrospective analysis (January 1999 to March 2000) of complication frequencies among PCI patients who underwent SMC and those who had manual compression (non-SMC). Furthermore, we compared the overall rates of complications to patients who underwent PCI prior to the introduction of SMC (1995-1998). When comparing the current cohort to the historical cohort, there was a significant decrease in the number of retroperitoneal bleeds (0.3% vs. 0.9%; P = 0.003), hematomas (5% vs. 9%; P < 0.001), pseudoaneurysms (1.2% vs. 2.7%; P < 0.001), and need for vascular surgery (0.9% vs. 2.8%; P < 0.001). There was no difference in the number of arterio-venous fistulas and a slight increase in transfusion needs (12% vs. 10%; P = 0.03). Within the current cohort, there was no difference in the vascular complications between SMC and non-SMC PCI patients, although there were lower rates of pseudoaneurysms (0.5% vs. 1.8%; P = 0.02) and transfusion requirements (72/880 vs. 132/874; P < 0.001). These results suggest that the complication rates for SMC are not different and may be lower when compared to non-SMC patients after PCI. At our institution, the practice of early sheath removal and less aggressive heparin dosing has led to a decrease in vascular complication rates and a 66% reduction in vascular surgeries on post-PCI patients. Because of the limitations of retrospective analyses, further studies will be necessary to confirm these findings.

Effects of norlaudanosolinecarboxylic acids on enzymes of catecholamine metabolism.

Enzymes involved in catecholamine metabolism were assayed in the presence of a new class of naturally occurring tetrahydroisoquinoline alkaloids, the norlaudanosolinecarboxylic acids (NLCAs). NLCAs inhibited tyrosine hydroxylase noncompetitively with respect to its substrate, tyrosine and the cofactor, 6-methyltetrahydropterin (NLCA Kj = 4 x 10(-4) M; 3',4'-deoxynorlaudanosolinecarboxylic acid (DNLCA) Kj = 1.5 x 10(-4) M). Adrenal dopamine-beta-hydroxylase was also inhibited by NLCAs [3'O-methylnorlaudanosolinecarboxylic acid (MNLCA) Kj = 1.2 x 10(-4) M] and NLCA is a competitive inhibitor of norepinephrine methylation by hepatic catechol-O-methyltransferase (NLCA Kj = 5.6 x 10(-5) M). While a slight reduction of rat adrenal monoamine oxidase by MNLCA was also observed, NLCA did not affect the oxidation of tyrosine by D-amino acid oxidase. Kinetic patterns of tyrosine aminotransferase and aromatic amono acid decarboxylase from rat liver were not altered by addition of 1 to 10 x 10(-5) M NLCA or its 3'-O-methyl ether (MNLCA). In vivo studies of brain tyrosine metabolism in mouse neonates corroborated results on the in vitro effect of DNLCA on tyrosine hydroxylase. The potential of high-pressure liquid chromatography was demonstrated in both enzyme assays and radiometric studies of in vivo metabolism.