Platelet Inhibition and Bleeding in Patients Undergoing Non-Cardiac Surgery-The BIANCA Observational Study.

Nearly 20% of patients will need non-cardiac surgery within 1 year of coronary stenting and their management is complicated by concomitant antiplatelet therapy. Platelet function testing may optimize the timing of surgery in these patients. In this prospective observational study, we explored the association between platelet reactivity and bleeding in patients undergoing non-cardiac surgery treated with clopidogrel with or without aspirin within 7 days before surgery. The timing of surgery was at the surgeon's discretion. Blood was drawn at induction of anaesthesia and platelet reactivity assessed by light transmittance aggregometry (LTA), vasodilator stimulated phosphoprotein (VASP) assay, Multiplate Analyzer and Innovance PFA-200. The primary endpoint was surgery-related thrombolysis in myocardial infarction (TIMI) bleeding. Among 197 patients enrolled, 72 and 12% underwent surgery within 24 and 48 hours of the last dose of clopidogrel, respectively. The median (interquartile range [IQR]) for pre-operative maximal adenosine diphosphate (ADP)-induced aggregation was 33.0% (21.0-57.5%), for VASP-platelet reactivity index was 61.5% (40.1-75.4%), for Multiplate was 22.0 (14.5-36.0) U*min and for Innovance PFA-200 was 224 (101.0-300.0) seconds. TIMI bleeding, observed in 25% of patients, decreased with increasing tertiles of platelet reactivity to ADP assessed by LTA (p = 0.031). Additionally, in a multivariable logistic regression analysis, platelet reactivity to ADP assessed by LTA was significantly associated with TIMI bleeding, as were age and urgency of surgery. These results demonstrate that in clopidogrel-treated patients, pre-operative platelet reactivity to ADP is associated with surgical bleeding risk. An objective assessment of pre-operative platelet function may optimize the timing of non-cardiac surgery in these patients.

Pneumatic tube system transport does not alter platelet function in optical and whole blood aggregometry, prothrombin time, activated partial thromboplastin time, platelet count and fibrinogen in patients on anti-platelet drug therapy.

INTRODUCTION: The aim of this study was to assess pneumatic tube system (PTS) alteration on platelet function by the light transmission aggregometry (LTA) and whole blood aggregometry (WBA) method, and on the results of platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen. MATERIALS AND METHODS: Venous blood was collected into six 4.5 mL VACUETTE® 9NC coagulation sodium citrate 3.8% tubes (Greiner Bio-One International GmbH, Kremsmünster, Austria) from 49 intensive care unit (ICU) patients on dual anti-platelet therapy and immediately hand carried to the central laboratory. Blood samples were divided into 2 Groups: Group 1 samples (N = 49) underwent PTS (4 m/s) transport from the central laboratory to the distant laboratory and back to the central laboratory, whereas Group 2 samples (N = 49) were excluded from PTS forces. In both groups, LTA and WBA stimulated with collagen, adenosine-5'-diphosphate (ADP), arachidonic acid (AA) and thrombin-receptor-activated-peptide 6 (TRAP-6) as well as platelet count, PT, APTT, and fibrinogen were performed. RESULTS: No statistically significant differences were observed between blood samples with (Group 1) and without (Group 2) PTS transport (P values from 0.064 - 0.968). The AA-induced LTA (bias: 68.57%) exceeded the bias acceptance limit of ≤ 25%. CONCLUSIONS: Blood sample transportation with computer controlled PTS in our hospital had no statistically significant effects on platelet aggregation determined in patients with anti-platelet therapy. Although AA induced LTA showed a significant bias, the diagnostic accuracy was not influenced.

[Periprocedual management of vitamin K antagonist's with low molecular weight heparins during invasive procedures--Consensus of experts]. / Niedermolekulare Heparine zur Überbrückung der Pause von Vitamin-K-Antagonisten während interventioneller Eingriffe ­ Expertenkonsensus.

Interruption of an ongoing therapy with vitamin K antagonists (VKAs) is necessary in almost all patients undergoing major surgery. The purpose of the following expert recommendations is to provide easy to use guidance for the periprocedural management of patients on VKAs based on current evidence from the literature. Management of anticoagulation during the time of interruption of VKAs is based on balancing the thromboembolic (TE) risk of underlying conditions against the bleeding risk of the surgical procedure. VKAs should be stopped 3­7days prior to surgery. Low molecular weight heparin (LMWH) is used to cover ("bridge") the progressive pre-operative loss of anticoagulation and the slow post-operative onset of anticoagulant activity of VKAs. Patients with high risk of TE should receive a therapeutic dose of LMWH, patients with a moderate risk of TE should receive half of this dose. Patients with a low risk of TE do not need bridging therapy with LMWH. In case of an uneventful postoperative course, patients with a therapeutic pre-operative dose should be treated post-operatively with the same dose, starting on day 4 in case of major surgery and on day 2 in case of minor procedures. Patients with a half-therapeutic preoperative dose should be treated post-operatively with the same dose, starting on day 3 in case of major surgery and on day 1 in case of minor procedures. Therapy with VKAs should be re-instituted on the second post-operative day based on the preoperative dosage. Procedure-related post-operative thromboprophylaxis should be given irrespective of these recommendations on days without "bridging" anticoagulation.

Platelet function measurement-based strategy to reduce bleeding and waiting time in clopidogrel-treated patients undergoing coronary artery bypass graft surgery: the timing based on platelet function strategy to reduce clopidogrel-associated bleeding related to CABG (TARGET-CABG) study.

BACKGROUND: Aspirin and clopidogrel therapy is associated with a variable bleeding risk in patients undergoing coronary artery bypass graft surgery (CABG). We evaluated the role of platelet function testing in clopidogrel-treated patients undergoing CABG. METHODS AND RESULTS: One hundred eighty patients on background aspirin with/without clopidogrel therapy undergoing elective first time isolated on-pump CABG were enrolled in a prospective single-center, nonrandomized, unblinded investigation (Timing Based on Platelet Function Strategy to Reduce Clopidogrel-Associated Bleeding Related to CABG [TARGET-CABG] study) between September 2008 and January 2011. Clopidogrel responsiveness (ADP-induced platelet-fibrin clot strength [MA(ADP)]) was determined by thrombelastography; CABG was done within 1 day, 3-5 days, and >5 days in patients with an MA(ADP) >50 mm, 35-50 mm, and <35 mm, respectively. The primary end point was 24-hour chest tube drainage and key secondary end point was total number of transfused red blood cells. Equivalence was defined as ≤25% difference between groups. ANCOVA was used to adjust for confounders. Mean 24-hour chest tube drainage in clopidogrel-treated patients was 93% (95% confidence interval, 81-107%) of the amount observed in clopidogrel-naive patients, and the total amount of red blood cells transfused did not differ between groups (1.80 U versus 2.08 U, respectively, P=0.540). The total waiting period in clopidogrel-treated patients was 233 days (mean, 2.7 days per patient). CONCLUSIONS: A strategy based on preoperative platelet function testing to determine the timing of CABG in clopidogrel-treated patients was associated with the same amount of bleeding observed in clopidogrel-naive patients and ≈50% shorter waiting time than recommended in the current guidelines. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00857155.

Usefulness of pre-operative copeptin concentrations to predict post-operative outcome after major vascular surgery.

The aim of this study was to investigate whether preoperative determination of plasma copeptin levels in addition to plasma N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) could help improve risk stratification in patients who undergo major vascular surgery. One hundred ninety-eight consecutive patients who underwent major vascular surgery (58.6% infrainguinal aortic reconstruction, 23.7% abdominal aortic aneurysm surgery, 17.7% carotid endarterectomy) were included in this study. Patients were monitored for in-hospital and long-term (2-years) major adverse cardiac events, consisting of cardiac death, nonfatal myocardial infarction, and emergent coronary revascularization. Overall, 40 patients (20.2%) reached the primary end point, and most of these events occurred during the index hospital stay (n = 18 [45%]). In univariate Cox regression analysis, increasing concentrations of copeptin were significant determinants of outcome as a continuous variable (hazard ratio [HR] 1.012, p = 0.005) and as a dichotomized variable according to the recommended cutoff of 14.0 pmol/L (HR 4.116, p <0.001). Subgroup analyses revealed that especially patients at low estimated risk according to plasma NT-pro-BNP levels were at significantly higher risk for worse outcomes with higher copeptin levels (HR 5.983, p = 0.002). In multivariate Cox regression analysis, copeptin concentrations >14 pmol/L were significant independent predictors of outcome (HR 2.842, p = 0.002) in addition to type of surgery, history of myocardial infarction, elevated levels of cardiac troponin T, and NT-pro-BNP levels. In conclusion, the results of this study suggest that preoperative determination of this new biomarker could substantially improve prediction of perioperative and postoperative outcomes in vascular surgery patients.

Geographic differences in the target-controlled infusion estimated concentration of propofol: bispectral index response curves.

PURPOSE: Variability in drug responses could result from both genetic and environmental factors. Thus, drug effect could depend on geographic location, although regional variation is not generally acknowledged as a basis for stratification. There is evidence that the pharmacokinetic set developed in a European population for the target-controlled infusion (TCI) of propofol does not apply in Chinese patients; however, we are not aware of previous studies comparing the estimated concentration-bispectral index (BIS) response of Caucasian patients in Europe with that of Chinese patients in China. METHODS: The Diprifusor™ TCI pump, incorporating the pharmacokinetic model proposed by Marsh et al., was applied to 30 Caucasian patients in Austria and 30 Chinese patients in China. The estimated plasma concentration (C(p)) of propofol for the two groups was set at 1 µg·mL(-1) and increased by 1 µg·mL(-1) every minute to gradually reach 5 µg·mL(-1) after 5 min. The BIS values were fitted against the estimated C(p) and the predicted effect-site concentration (C(e)) in a sigmoid E(max) model. RESULTS: The sigmoid E(max) curves were shifted significantly to the left in the Chinese group compared with the Austrian group. After 5 min, the BIS value in the Chinese group was lower than in the Austrian group (mean ± standard deviation [SD], 47.2 ± 3.6 vs 63.6 ± 5.4, respectively; P = 0.0006). The estimated C(p) at loss of consciousness (LOC), predicted C(e) at LOC, and time to LOC, were lower in the Chinese group than in the Austrian group (3.3 ± 0.8 µg·mL(-1), 1.6 ± 0.4 µg·mL(-1), 2.8 ± 0.6 min, respectively, vs 4.6 ± 2.8 µg·mL(-1), 2.4 ± 1.5 µg·mL(-1), 3.9 ± 0.5 min, respectively; P < 0.0001). CONCLUSION: When propofol is given using the same TCI protocol, Chinese patients in China lost consciousness faster and at a lower estimated plasma concentration than Caucasians in Austria. Larger studies are needed to map geographically appropriate TCI infusion models.

Controversies in oral antiplatelet therapy in patients undergoing aortocoronary bypass surgery.

Oral antiplatelet therapy with aspirin and clopidogrel is a major strategy to prevent thrombotic events in patients with acute coronary syndromes and patients undergoing percutaneous coronary interventions. Although this therapy is associated with both short- and long-term clinical efficacy, irreversible platelet inhibition and ischemic events associated with premature withdrawal especially in patients treated with drug-eluting stents constitute a particular limitation in patients undergoing surgery. The current review article is focused on the central role of platelets in the occurrence of ischemic events, the significance of antiplatelet therapy, the potential hazards of drug withdrawal in patients needing coronary artery bypass grafting, and future perspectives.

The utility of using the bispectral index-Vista for detecting cross-clamping decline in cerebral blood flow velocity.

BACKGROUND: Patients undergoing carotid endarterectomy for extracranial internal carotid artery stenosis are at risk of cerebral ischemia/hypoperfusion. Criterion recommended by European and American committees to determine whether to place a shunt consisted of a decline in transcranial Doppler ultrasonography-measured middle cerebral artery blood flow velocity (MCBFV) to < 30% to 40% of intraoperative preclamp value. OBJECTIVE: To assess the discriminative power of the bispectral index (BIS)-Vista monitor for detecting a 40% decline in MCBFV with cross-clamping. METHODS: In 20 patients undergoing carotid endarterectomy under remifentanil/propofol anesthesia, BIS-Vista data, MCBFV, and pulsatility index from bilaterally mounted BIS-Vista and transcranial Doppler monitors were continuously recorded. RESULTS: Coefficient of determination revealed good correlation (r = 0.763) between ipsilateral BIS-Vista and MCBFV after cross-clamping. BIS-Vista exhibited a high discriminative power of 0.850 (95% confidence interval, 0.455-0.966) area under the receiver-operating characteristic curve in detecting an ipsilateral 40% MCBFV decline. Two-way analysis of variance (location by time) suggests that BIS-Vista exhibited a global decline; ie, both BIS-Vistas declined when 1 carotid on either side was clamped because there was no significant interhemispheric difference (P = .112) in mean BIS-Vista values over time. CONCLUSION: Although we demonstrated good correlation and high discriminative power of the BIS-Vista monitor in depicting a MCBFV decline that could serve as indicator of decline in cerebral activity, BIS-Vista cannot be considered a reliable indicator of cerebral ischemia/hypoperfusion that could replace transcranial Doppler monitoring to determine whether a shunt is to be placed.

BIS-vista occipital montage in patients undergoing neurosurgical procedures during propofol-remifentanil anesthesia.

BACKGROUND: Neurosurgical procedures that require a frontal approach could be an impediment for a successful Bispectral Index (BIS) frontal sensor placement. The aim of this study was to explore the utility of using the new BIS-Vista monitor (Aspect Medical Systems, Newton, MA) for occipital sensor placement in the patients undergoing brain neurosurgical procedures during propofol-remifentanil anesthesia. METHODS: Two BIS Quatro sensors (Aspect Medical Systems, Newton, MA) mounted on the occipital and frontal regions were connected to two BIS-Vista monitors at three anesthesia states: before induction, during anesthesia maintenance, and recovery. RESULTS: There were significant differences before induction (P = 0.0002) and at anesthesia maintenance (P = 0.0014) between mean +/- SD occipital (83.4 +/- 4.8, 66.7 +/- 7.2) and frontal (93.1 +/- 3.4, 56.9 +/- 9.1) BIS-Vista values. During anesthesia recovery, there was no difference (P = 0.7421) between occipital (54.6 +/- 9.3) and frontal (53.1 +/- 7.3) BIS-Vista values. Bland and Altman analysis revealed a BIS-Vista negative-bias (limits of agreement) of -9.7 (+1.1, -20.5) before anesthesia induction, +9.8 positive-bias (+22.8, -1.7) during anesthesia maintenance, and -0.9 bias (+10.9, -12.8) during anesthesia recovery. CONCLUSION: We demonstrated that not only the regional limits of agreement are too wide to allow data of the two montages to be used interchangeably but also the variation is a function of anesthetic depth. However, keeping in mind a relatively consistent BIS-Vista -10 bias before induction and +10 bias during anesthesia maintenance with limits of agreement of approximately +/-11 BIS units, approximately double the clinically acceptable less than 10 BIS units level of agreement, BIS-Vista off-label occipital montage might be helpful in following a trend of propofol-remifentanil anesthesia in individual cases where frontal access is particularly difficult.

Premature preoperative discontinuation of antiplatelet drug therapy in cardiovascular risk patients: a preliminary study on the role of P2Y12 receptor monitoring.

BACKGROUND AND OBJECTIVE: In high-bleeding risk procedures, discontinuation of antiplatelet drug therapy with clopidogrel may be requested by surgeons, usually 7-10 days before the surgical procedure. New platelet function tests, such as the vasodilator-stimulated phosphoprotein phosphorylation assay, may help to assess the perioperative status of the clopidogrel-specific P2Y12 receptor. METHODS: Using vasodilator-stimulated phosphoprotein phosphorylation assay, the platelet reactivity index (PRI) was measured in 80 individuals, including 20 healthy volunteers, 20 cardiologic patients under full antiplatelet drug therapy with clopidogrel and aspirin, 20 surgical patients without any antiplatelet drugs and 20 patients under clopidogrel, discontinued 7 days before the surgical procedure. RESULTS: The mean PRI (95% confidence interval) in healthy volunteers was 86 (82-89%) and that in the surgical control group was 77% (72-81%). In cardiologic patients under full antiplatelet therapy, mean PRI was 51% (42-60%). In the clopidogrel discontinuation group, PRI increased from 51% (40-62%) on day 0 to 65% (57-74%) on day 3 and to 76% (69-84%) on day 5. On the morning of surgery, mean PRI was 85% (80-91%). The PRI values on the 5th day were equivalent to those of the surgical control group (mean difference -0.4%, 95% confidence interval -8.6% to 7.8%, P = 0.9). Fifty-five percent of the patients in the discontinuation group had a PRI of more than 50% on day 0. CONCLUSION: The study using vasodilator-stimulated phosphoprotein phosphorylation assay, one of the new platelet function assays for the assessment of inhibition of platelet P2Y12 receptor, demonstrates that the PRI on day 5 after discontinuation of clopidogrel is equivalent to a surgical control group and it questions the rigid practice of delaying surgery for 7-10 days, particularly in patients without a clopidogrel effect.

The patient with coronary stents and antiplatelet agents: what to do and how to deal?

The management of patients with recent coronary artery stents presenting for noncardiac surgery has become a major topic of interest and concern for all perioperative care givers. The present review will update recent reports and particularly new guidelines as well as recommendations. Based on the available literature, all experts recommend avoiding premature discontinuation of antiplatelet drug therapy if possible except for a few surgical procedures. Drug-eluting stents obviously carry more risks than bare-metal stents.

Effect of flumazenil on bispectral index monitoring in unpremedicated patients.

BACKGROUND: Flumazenil is an imidazobenzodiazepine that promptly reverses via competitive inhibition the hypnotic/sedative effects of benzodiazepines on gamma-aminobutyric acid receptors. Endogenous benzodiazepine ligands (endozepines) were isolated in urine, cerebrospinal fluid, and breast milk of women who had not received benzodiazepines. The bispectral index (BIS), an electroencephalographically derived parameter widely used for monitoring the effects of anesthetic/hypnotic drugs, was shown to correlate to various conditions that could influence electroencephalography. The authors examined the hypothesis that 0.5 mg of flumazenil administered to healthy unpremedicated patients during deep surgical remifentanil/propofol anesthesia would increase the BIS value and might expedite recovery from anesthesia. METHODS: Sixty healthy unpremedicated patients were randomly allocated to the flumazenil or control groups. After study drug administration, the authors compared BIS values and various recovery parameters in the flumazenil and control groups. RESULTS: BIS baseline values in the flumazenil group (38.7 +/- 3.8) increased 15 min after flumazenil administration (53.2 +/- 4.7), with a significant difference over time (P < 0.0001) between the two groups. Mean recovery parameters time, comprising time to spontaneous breathing, eye opening/hand squeezing on verbal command, extubation, and date of birth recollection, was significantly shorter (P = 0.0002) in the flumazenil group (6.9 +/- 2.6 min) compared with the control group (9.8 +/- 2.9 min). CONCLUSIONS: This study demonstrates that flumazenil given to healthy unpremedicated patients during propofol/remifentanil anesthesia significantly increased the BIS value and allowed earlier emergence from anesthesia. This may indicate that flumazenil could be used on a case-by-case basis to reverse endogenous or exogenous endozepines that might play a role during anesthesia.

The effects of fibrinogen levels on thromboelastometric variables in the presence of thrombocytopenia.

BACKGROUND: The binding of fibrinogen and fibrin to platelets is important in normal hemostasis. The extent of platelet-fibrin interaction can be measured as the viscoelastic strength of clot by rotational thromboelastometry (ROTEM). In this study, we investigated the effect of fibrinogen concentration and its relative contribution to overall clot strength using ROTEM. METHODS: Blood samples were collected from healthy volunteers. The effects of platelet count on clot strength, determined by maximum clot elasticity (MCE), were evaluated on ROTEM using platelet-rich plasma (PRP) adjusted with autologous plasma to generate a range of platelet counts. PRPs were adjusted to 10 x 10(3) mm(-3), 50 x 10(3) mm(-3), and 100 x 10(3) mm(-3) and spiked with fibrinogen concentrates at 550 and 780 mg/dL. The effect of fibrin polymerization on clot strength, independent of platelet attachment, was analyzed by the cytochalasin D-modified thromboelastometry (FIBTEM) method. Additional retrospective analysis of clot strength (MCE) in two groups of thrombocytopenic patients was conducted. RESULTS: Clot strength (MCE) decreased at a platelet count below 100 x 10(3) mm(-3), whereas increases in MCE peaked and reached a plateau at platelet counts from 400 x 10(3) mm(-3). Increasing fibrinogen concentrations in PRP increased clot strength in a concentration-dependent manner, even at low platelet counts (10 x 10(3) mm(-3)). The positive correlation between clot strength and plasma fibrinogen level was also confirmed in the analysis of the data obtained from 904 thrombocytopenic patients. CONCLUSIONS: These in vitro and clinical data indicate that the clot strength increases in a fibrinogen concentration-dependent manner independent of platelet count, when analyzed by ROTEM. The maintenance of fibrinogen concentration is critical in the presence of thrombocytopenia. EXTEM (extrinsic activation) and FIBTEM may be useful in guiding fibrinogen repletion therapy.

Bispectral index monitoring of a narcolepsy-cataplexy episode during regional anesthesia.

Narcolepsy or Gélineau syndrome is an extremely incapacitating chronic sleep disorder of unknown etiology that is characterized by uncontrollable attacks of deep sleep and is typically associated with cataplexy sudden loss of muscle tone. The Bispectral Index (BIS), an electroencephalographic-derived cerebral monitor, used for monitoring the effects of anesthetic/hypnotic drugs was shown to correlate to various conditions that could influence the eletroencephalogram. We assessed the utility of using BIS for monitoring a possible narcolepsy-cataplexy episode and whether a distinctive BIS profile might offer an early warning of an impending narcoleptic/cataplectic spell. We recorded both hemispheres, using two synchronized BIS-XP monitors, during a narcolepsy-cataplexy episode in a 57-yr-old male patient undergoing lower limb surgery under femoral nerve block regional anesthesia. The patient went through three stages: first a prodromal "intermittent low-vigilance" phase interrupted by high electromyographic activity. This was followed by a second "continuous low-vigilance" phase of BIS around 75 with low electromyographic activity, ending with a third "nonresponsive vigilance" phase of a full-blown narcolepsy-cataplexy episode of BIS around 45 with complete loss of muscle power. The purpose of presenting this report is to emphasize the fact that narcoleptic patients can still run the risk of loss of consciousness with atonia under regional anesthesia, and such an undesirable complication cannot be under-estimated. BIS monitoring is a simple method that could offer an early warning of an imminent episode, with its associated hazards, in patients with narcolepsy-cataplexy undergoing surgery under regional anesthesia.

Effect of somatostatin analogue octreotide on pain relief after major abdominal surgery.

BACKGROUND: Octreotide acetate is an 8-amino-acids synthetic octapeptide analogue of somatostatin with much-enhanced duration of action and lower incidence of side effects. We assessed the utility of using intravenous octreotide as an adjuvant to opioid analgesia that might exert a post-operative opioid-sparing effect. METHODS: Forty-four patients were randomly allocated, to receive either a placebo or intraoperative octreotide 0.33 microg kg(-1)h(-1) intravenous infusion that was maintained in the post-operative period. Patients received for post-operative analgesia an intravenous piritramide patient controlled analgesia (PCA), set to deliver a piritramide 0.02 mgkg(-1) dose. RESULTS: Two-way ANOVA revealed significantly fewer (P=0.0003) mean+/-SD weighted piritramide dose requirements in the octreotide group (19.5+/-6.3 microg kg(-1)h(-1)) than in the control group (35.7+/-8.2 microg kg(-1)h(-1)). Dunnett's two-sided multiple-comparison post hoc test revealed a significant difference between the two groups during the first 22 post-operative hours, following which there were no differences between the two groups. There were no significant differences over time in the mean arterial pressure (P=0.722), heart rate (P=0.579) and respiratory rate (P=0.823) between the octreotide group (80+/-10mm Hg, 74+/-12, 14+/-2) and the control group (82+/-9 mm Hg, 76+/-11, 15+/-3), respectively. CONCLUSION: We demonstrated that perioperative octreotide intravenous infusion could be an adjuvant to opioid analgesia as it exerted a piritramide opioid-sparing effect. We encountered more systemic side effects such as nausea, abdominal discomfort, and diarrhea in the octreotide group than in the control group. Our findings could be beneficial to patients who cannot tolerate the adverse effects of opioids.

Antiplatelet therapy and coronary stents in perioperative medicine--the two sides of the coin.

New trends in interventional cardiology, e.g. the increasing practice of coronary intervention with stent implantation and the prolonged use of dual antiplatelet therapy--usually a combination of clopidogrel and aspirin--has also increased the number of patients presenting for non-cardiac surgery. The two most commonly used stent types, bare-metal stents (BMSs) and drug-eluting stents (DESs), mandate different lengths of dual antiplatelet drug therapy to avoid stent thrombosis. Perioperative caregivers face a knife-edge dilemma between perioperative stent thrombosis, due to preoperative discontinuation of antiplatelet drugs, or surgical bleeding, by continuation of therapy. Pre- and intraoperatively, the risk factors for thrombosis have to be balanced against the risk factors for surgical bleeding. As long as prospective trials are not available, the recommendations and guidelines of task forces and experts are based on retrospective studies and case reports. The perioperative management, decision trees and the importance of close interdisciplinary collaboration between cardiologists, surgeons and anaesthetists will be described.

Gastrointestinal motility in acute illness.

Critical illness affects gastrointestinal motility - not only as a primary problem, which brings the patient to the intensive care unit (ICU), but also as a complication consecutive to the ICU stay. Motility disturbances may result from impaired function of gastrointestinal muscle, pacemaker cell function and nerve activity. The most important neural control system is the enteric nervous system that contains the largest collection of neurons (10(8) cells) outside the central nervous system. Through its organization it can operate independently of the brain and generate motility patterns according to need: a postprandial motility pattern starting after food intake, and an interdigestive motility pattern starting several hours after a meal. Undisturbed intestinal motility depends critically on a balanced interaction between inhibition and excitation, and a disturbance in this balance leads to severe derangements of intestinal motility. These motility disturbances differ in clinical appearance and location but can affect all parts of the gastrointestinal tract. This review focuses on select motility disturbances such as gastroparesis, postoperative ileus, and Ogilvie's syndrome. Generally effective methods to treat these conditions are given. Finally, we focus on special management options to prevent such motility disturbances or to reduce their severity.

Anaesthesia in patients with drug-eluting stents.

PURPOSE OF REVIEW: The management of patients with recent coronary artery stents presenting for noncardiac surgery has become a major topic of interest and concern for all perioperative caregivers. This review will update recent reports and particularly new guidelines as well as recommendations. RECENT FINDINGS: Based on the available literature all experts recommend avoiding premature discontinuation of antiplatelet drug therapy if possible except for a few surgical procedures. Drug-eluting stents obviously carry more risks than bare-metal stents. SUMMARY: Anaesthesiologists may understand the specific problem of drug-eluting stents, the recent debate among cardiologists and the implications for the perioperative scenario.

N-terminal pro-brain natriuretic peptide identifies patients at high risk for adverse cardiac outcome after vascular surgery.

BACKGROUND: Preoperative N-terminal pro-BNP (NT-proBNP) is independently associated with adverse cardiac outcome but does not anticipate the dynamic consequences of anesthesia and surgery. The authors hypothesized that a single postoperative NT-proBNP level provides additional prognostic information for in-hospital and late cardiac events. METHODS: Two hundred eighteen patients scheduled to undergo vascular surgery were enrolled and followed up for 24-30 months. Logistic regression and Cox proportional hazards model were performed to evaluate predictors of in-hospital and long-term cardiac outcome. The optimal discriminatory level of preoperative and postoperative NT-proBNP was determined by receiver operating characteristic analysis. RESULTS: During a median follow-up of 826 days, 44 patients (20%) experienced 51 cardiac events. Perioperatively, median NT-proBNP increased from 215 to 557 pg/ml (interquartile range, 83/457 to 221/1178 pg/ml; P<0.001). The optimum discriminate threshold for preoperative and postoperative NT-proBNP was 280 pg/ml (95% confidence interval, 123-400) and 860 pg/ml (95% confidence interval, 556-1,054), respectively. Adjusted for age, previous myocardial infarction, preoperative fibrinogen, creatinine, high-sensitivity C-reactive protein, type, duration, and surgical complications, only postoperative NT-proBNP remained significantly associated with in-hospital (adjusted hazard ratio, 19.8; 95% confidence interval, 3.4-115) and long-term cardiac outcome (adjusted hazard ratio, 4.88; 95% confidence interval, 2.43-9.81). CONCLUSION: A single postoperative NT-proBNP determination provides important additional prognostic information to preoperative levels and may support therapeutic decisions to prevent subsequent structural myocardial damage.