bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guidelines for Cardiac Management in Noncardiac Surgery Are Poorly Implemented in Clinical Practice
Authors: Hoeks Sanne E. , Scholte op Reimer Wilma J. M. , Lenzen Mattie J. , van Urk Hero , Jörning Paul J. G. , Boersma Eric , Simoons Maarten L. , Bax Jeroen J. , Poldermans Don 
Published: March 2009

Background
The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery recommend an algorithm for a stepwise approach to preoperative cardiac assessment in vascular surgery patients. The authors' main objective was to determine adherence to the ACC/AHA guidelines on perioperative care in daily clinical practice.

Methods
Between May and December 2004, data on 711 consecutive peripheral vascular surgery patients were collected from 11 hospitals in The Netherlands. This survey was conducted within the infrastructure of the Euro Heart Survey Programme. The authors retrospectively applied the ACC/AHA guideline algorithm to each patient in their data set and subsequently compared observed clinical practice data with these recommendations.

Results
Although 185 of the total 711 patients (26%) fulfilled the ACC/AHA guideline criteria to recommend preoperative noninvasive cardiac testing, clinicians had performed testing in only 38 of those cases (21%). Conversely, of the 526 patients for whom noninvasive testing was not recommended, guidelines were followed in 467 patients (89%). Overall, patients who had not been tested, irrespective of guideline recommendation, received less cardioprotective medications, whereas patients who underwent noninvasive testing were significantly more often treated with cardiovascular drugs (beta-blockers 43% vs. 77%, statins 52% vs. 83%, platelet inhibitors 80% vs. 85%, respectively; all P < 0.05). Moreover, the authors did not observe significant differences in cardiovascular medical therapy between patients with a normal test result and patients with an abnormal test result.

Conclusion
This survey showed poor agreement between ACC/AHA guideline recommendations and daily clinical practice. Only one of each five patients underwent noninvasive testing when recommended. Furthermore, patients who had not undergone testing despite recommendations received as little cardiac management as the low-risk population.
Accuracy of Cerebral Monitoring in Detecting Cerebral Ischemia during Carotid Endarterectomy
Authors: Moritz Stefan , Kasprzak Piotr , Arlt Matthias , Taeger Kai , Metz Christoph 
Published: March 2009

Background
This study compares the accuracy of cerebral monitoring systems in detecting cerebral ischemia during carotid endarterectomy.

Methods
The authors compared transcranial Doppler sonography (TCD), near-infrared spectroscopy (NIRS), stump pressure (SP) measurement, and somatosensory evoked potentials (SEP) in 48 patients undergoing carotid surgery during regional anesthesia. Cerebral ischemia was assumed when neurologic deterioration occurred. During clamping, the minimum mean middle cerebral artery velocity (TCD(min)), its percentage change (TCD%), the minimum regional saturation of oxygen (NIRS(min)), its percentage change (NIRS%), the mean SP, and the changes of SEP amplitude were recorded. To analyze the corresponding sensitivity and specificity of each parameter, the authors performed receiver operating characteristic analysis.

Results
Neurologic deterioration occurred in 12 patients. SP and NIRS were successfully performed in all patients. TCD monitoring was not possible in 10 (21%); SEP was not possible in 2 patients (4%). All parameters provided the ability to distinguish between ischemic and nonischemic patients. TCD% and NIRS% showed significantly better discrimination than TCD(min) and NIRS(min) (P < 0.05). The highest area under the curve (AUC) was found for TCD% (AUC = 0.973), but there was no significant difference compared with NIRS% (AUC = 0.905) and SP (AUC = 0.925). The lowest AUC was found for SEP (AUC = 0.749), which was significantly lower than that for TCD%, NIRS%, and SP.

Conclusions
TCD%, NIRS%, and SP measurement provide similar accuracy for the detection of cerebral ischemia during carotid surgery. Lower accuracy was found for SEP monitoring. Because of the high rate of technical difficulties (21%), TCD monitoring was the least practical of the investigated monitoring devices.
Effects of Age and Emotionality on the Effectiveness of Midazolam Administered Preoperatively to Children
Authors: Kain Zeev N. , MacLaren Jill , McClain Brenda C. , Saadat Haleh , Wang Shu-Ming , Mayes Linda C. , Anderson George M. 
Published: March 2009

Background
Multiple studies document the beneficial effect of midazolam on preoperative anxiety in children. Many clinicians report, however, that some children may in fact not benefit from the administration of this drug.

Methods
After screening for relevant exclusion criteria, children undergoing surgery were enrolled in the study (n = 262) and received 0.5 mg/kg oral midazolam at 20-40 min before induction of anesthesia. Personality instruments were administered to all children, and anxiety levels were evaluated before and after administration of midazolam as well as during induction of anesthesia. Blood was drawn during the induction process and later analyzed for midazolam levels. A priori definitions of responders and nonresponders to midazolam were established using a multidisciplinary task force, videotapes of induction, and a validated and reliable anxiety scale, the modified Yale Preoperative Anxiety Scale.

Results
While 57% of all children scored at the minimum of the modified Yale Preoperative anxiety scale, 14.1% of children fell in the a priori defined group of midazolam nonresponders. Midazolam blood levels (94 +/- 41 vs. 109 +/- 40 ng/ml) and timing between administration of midazolam and induction (28 +/- 9 vs. 29 +/- 8 min) did not differ between midazolam responders and nonresponders. In contrast, midazolam nonresponders were younger (4.2 +/- 2.3 vs. 5.9 +/- 2.0 yr), more anxious preoperatively (49.7 +/- 22.9 vs. 38.3 +/- 19.1), and higher in emotionality (13.6 +/- 3.6 vs. 11.3 +/- 3.8) as compared with responders (P < 0.05).

Conclusions
Although midazolam is an effective anxiolytic for most children, 14.1% of children still exhibit extreme distress. This subgroup is younger, more emotional, and more anxious at baseline. Future studies are needed to determine the best strategy to treat these children.
Effects of Extreme Hemodilution during Cardiac Surgery on Cognitive Function in the Elderly
Authors: Mathew Joseph P. , Mackensen G Burkhard , Phillips-Bute Barbara , Stafford-Smith Mark , Podgoreanu Mihai V. , Grocott Hilary P. , Hill Steven E. , Smith Peter K. , Blumenthal James A. , Reves J G. , Newman Mark F. 
Published: March 2009

Background
Strategies for neuroprotection including hypothermia and hemodilution have been routinely practiced since the inception of cardiopulmonary bypass. Yet postoperative neurocognitive deficits that diminish the quality of life of cardiac surgery patients are frequent. Because there is uncertainty regarding the impact of hemodilution on perioperative organ function, the authors hypothesized that extreme hemodilution during cardiac surgery would increase the frequency and severity of postoperative neurocognitive deficits.

Methods
Patients undergoing coronary artery bypass grafting surgery were randomly assigned to either moderate hemodilution (hematocrit on cardiopulmonary bypass >or=27%) or profound hemodilution (hematocrit on cardiopulmonary bypass of 15-18%). Cognitive function was measured preoperatively and 6 weeks postoperatively. The effect of hemodilution on postoperative cognition was tested using multivariable modeling accounting for age, years of education, and baseline levels of cognition.

Results
After randomization of 108 patients, the trial was terminated by the Data Safety and Monitoring Board due to the significant occurrence of adverse events, which primarily involved pulmonary complications in the moderate hemodilution group. Multivariable analysis revealed an interaction between hemodilution and age wherein older patients in the profound hemodilution group experienced greater neurocognitive decline (P = 0.03).

Conclusions
In this prospective, randomized study of hemodilution during cardiac surgery with cardiopulmonary bypass in adults, the authors report an early termination of the study because of an increase in adverse events. They also observed greater neurocognitive impairment among older patients receiving extreme hemodilution.
4-Aminopyridine Restores Impaired Hypoxic Pulmonary Vasoconstriction in Endotoxemic Mice
Authors: Spöhr Fabian , Busch Cornelius J. , Reich Christian , Motsch Johann , Gebhard Martha M. , Kuebler Wolfgang M. , Bloch Kenneth D. , Weimann Jörg 
Published: March 2009

Background
Hypoxic pulmonary vasoconstriction (HPV) is impaired during inflammatory lung processes such as pneumonia or the acute respiratory distress syndrome. Voltage-gated potassium channels play a central role in mediating HPV. The aim of this study was to determine whether 4-aminopyridine (4-AP), a known voltage-gated potassium channel inhibitor, may restore HPV in sepsis.

Methods
The effects of 0.01, 0.1, and 1.0 mm 4-AP on HPV responsiveness were assessed in isolated lungs of untreated mice and of mice 18 h after lipopolysaccharide injection (20 mg/kg intraperitoneal Escherichia coli 0111:B4 lipopolysaccharide). HPV was quantified as the increase in perfusion pressure in response to hypoxic ventilation in percent of baseline perfusion pressure. Intrinsic pulmonary vascular resistance (R0) and pulmonary vascular distensibility (alpha) were determined by nonlinear regression analysis of pulmonary vascular pressure-flow curves generated during normoxic and hypoxic ventilation, respectively.

Results
HPV was impaired in lungs isolated from lipopolysaccharide-challenged mice. Addition of 4-AP to the perfusate did not alter HPV responsiveness in untreated mice but dose dependently restored HPV in endotoxemic mice. Analysis of pulmonary vascular pressure-flow curves revealed that 4-AP (1) counteracted the observed lipopolysaccharide-induced changes in alpha and R0 under normoxic conditions and (2) augmented the hypoxia-induced increase in R0 in lungs of endotoxemic mice.

Conclusions
This study demonstrates that lipopolysaccharide-induced pulmonary vascular hyporesponsiveness to hypoxia can be restored by 4-AP in murine endotoxemia and, thus, may be a new therapeutic approach to treat patients with hypoxemia due to impaired HPV.
Exogenous Ethyl Pyruvate versus Pyruvate during Metabolic Recovery after Oxidative Stress in Neonatal Rat Cerebrocortical Slices
Authors: Zeng Jianying , Liu Jia , Yang Guo-Yuan , Kelly Mark J. S. , James Thomas L. , Litt Lawrence 
Published: March 2009

Background
Exogenous pyruvate and ethyl pyruvate (EP), the key ingredient in a new Ringer's solution in clinical trials, are antioxidants as well as metabolic substrates. In vivo studies show both to be protective in oxidative stress, with EP being better. The authors used an acute rat brain slice preparation to compare EP and pyruvate rescue after H(2)O(2) oxidative stress, asking whether EP was again better and whether its actions were exclusively metabolic.

Methods
Oxygenated neonatal P7 cerebrocortical slices were exposed for 1 h to 2 mM H(2)O(2), and recovered for 4 h with artificial cerebrospinal fluid having 2 mM glucose and (1) 20 mM EP, (2) 20 mM pyruvate, or (3) 1 mM of the nonmetabolizable radical scavenger N-tert-butyl-alpha-phenylnitrone (PBN). Perchloric acid extracts were studied with 31P/1H nuclear magnetic resonance at 14.1 T. Acute cell injury was assessed by counting terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling (TUNEL)-stained cells.

Results
At the end of recovery, preservation of adenosine triphosphate and N-acetylaspartate was better with EP than with pyruvate. Adenosine triphosphate preservation was best when PBN and EP were coadministered. 1H nuclear magnetic resonance revealed changes in lactate, alanine, gamma-aminobutyric acid, glutamate, glutamine, succinate, taurine, and myoinositol. Two-dimensional [1H-13C] heteronuclear single quantum coherence spectroscopy found that 13C-EP administration produced the same tricarboxylic acid metabolites as C-pyruvate. TUNEL-positive cell percentages with EP were less than half of those for PBN or pyruvate rescue (P < 0.05).

Conclusion
EP enters cells, provides pyruvate as a tricarboxylic acid substrate, and is more protective. Although EP provides metabolic protection of adenosine triphosphate levels, it does not maximize antioxidant protection.
Intramuscular Injection of Sevoflurane Detects Malignant Hyperthermia Predisposition in Susceptible Pigs
Authors: Schuster Frank , Metterlein Thomas , Negele Sabrina , Gardill Annegret , Schwemmer Ulrich , Roewer Norbert , Anetseder Martin 
Published: March 2009

Background
The authors hypothesized that intramuscular sevoflurane injection allows diagnostic differentiation between malignant hyperthermia-susceptible (MHS) and -nonsusceptible (MHN) pigs by measurement of intramuscular lactate and carbon dioxide partial pressure (PCO2), and that dantrolene reduces the sevoflurane-induced PCO2 increase.

Methods
With approval of the local animal care committee, microdialysis probes with attached microtubing for sevoflurane injection were placed in the adductor muscles of nine MHS and six MHN pigs, and PCO2 probes with microtubing were positioned in the triceps muscle of eight MHS and six MHN pigs. After equilibration, sevoflurane boluses at different concentrations and a sevoflurane-dantrolene bolus were injected synchronously. Lactate, pyruvate, and glucose as well as PCO2 were measured spectrophotometrically, and the rate of PCO2 increase was calculated.

Results
Intramuscular sevoflurane injection increased local lactate and PCO2 dose dependently, and significantly higher in MHS than in MHN pigs. Measurement of the rate of PCO2 increase allowed a distinct differentiation between single MHS and MHN pigs. No significant increase in PCO2 was found with sevoflurane and dantrolene.

Conclusions
Local sevoflurane induces a hypermetabolic reaction measured by PCO2 and lactate increases. The reduced PCO2 increase in MHS after sevoflurane and dantrolene injection is likely to be a result of the sevoflurane-mediated calcium release and its antagonism by dantrolene. Sevoflurane may be useful for a less invasive diagnostic test for malignant hyperthermia in humans.
Fiberoptic Intubation and Laryngeal Morbidity
Authors: Heidegger Thomas , Starzyk Lukas , Villiger Cornelia R. , Schumacher Stefan , Studer Rolf , Peter Barbara , Nuebling Matthias , Gerig Hans J. , Schnider Thomas W. 
Published: March 2009

Background
Tracheal intubation with neuromuscular blocking agents is associated with a low incidence of minor vocal cord sequelae (8%). The aim of this noninferiority trial was to demonstrate that the frequency of vocal cord sequelae after fiberoptic intubation with a flexible silicone tube without neuromuscular blocking agents was less than 25% (maximum tolerable inferiority).

Methods
Two-hundred seventy patients were prospectively randomized to two groups. All intubations were performed by anesthesiologists with extensive experience in fiberoptic and conventional techniques. Fiberoptic nasotracheal intubation consisted of a bolus dose of 2 microg/kg fentanyl; 0.25 ml cocaine instillation, 10%, into nasal canals; cricothyroid injection of 2 ml lidocaine, 1%; bronchoscopy; administration of 0.3 mg/kg etomidate; and advancing a flexible silicone tube after loss of consciousness. Orotracheal intubation was performed with a polyvinyl chloride tube after induction with 2 microg/kg fentanyl, 2 mg/kg propofol, and 0.6 mg/kg rocuronium. Patients were examined by laryngoscopy before surgery, 24 h after surgery, and daily until complete restitution. Postoperative hoarseness was assessed by a standardized interview.

Results
The incidence of vocal cord sequelae was 11 out of 130 (8.5%) in the fiberoptic group versus 12 out of 129 (9.3%) in the control group (chi-square = 0.057, df = 1, P = 0.81; upper limit of the one-sided 95% confidence interval for the difference: +5.1%). There were no persistent injuries. The incidence of postoperative hoarseness was 4% in both groups.

Conclusions
Because fiberoptic intubation without neuromuscular blocking agents is safe regarding vocal cord sequelae, routine use is justified for anesthesiologists experienced in this technique.
Presynaptic and Postsynaptic Effects of the Anesthetics Sevoflurane and Nitrous Oxide in the Human Spinal Cord
Authors: Baars Jan H. , Benzke Michael , von Dincklage Falk , Reiche Josephine , Schlattmann Peter , Rehberg Benno 
Published: March 2009

Background
Reduced spinal excitability contributes to the suppression of movement responses to noxious stimuli during the anesthetic state. This study examines and compares presynaptic and postsynaptic effects of two anesthetics in the human spinal cord.

Methods
The authors tested two parameters during the administration of 0.8 vol% sevoflurane or 40 vol% nitrous oxide compared with control states before and after drug administration: (1) the size of the soleus H reflex (integrating presynaptic and postsynaptic effects) at increasing stimulus intensities (recruitment curve) and (2) the amount of presynaptic inhibition on Ia afferents of the quadriceps femoris, evaluated by the heteronymous facilitation of the soleus H reflex caused by a conditioning stimulation of the femoral nerve. The study was performed in 10 subjects for each drug.

Results
At the chosen concentrations, the maximum H reflex was reduced by 26.3 +/- 8.4% (mean +/- SD) during sevoflurane and by 33.5 +/- 15.6% during nitrous oxide administration. The averaged recruitment curves were similarly depressed under the influence of the two drugs. The reduction of H-reflex facilitation was significantly stronger for sevoflurane (28.8 +/- 20.0%) than for nitrous oxide administration (6.2 +/- 26.4%).

Conclusions
These results demonstrate in humans presynaptic effects of the volatile anesthetic sevoflurane but not of nitrous oxide. A possible explanation for this difference may be the different potency of the respective drugs in enhancing gamma-aminobutyric acid type A receptor-mediated inhibition, because presynaptic inhibition in the spinal cord involves this receptor subtype.
A Retrospective Assessment of Magnetic Resonance Cholangiopancreatography in Children
Authors: Tipnis Neelesh A , Dua Kulwinder S , Werlin Steven L 
Published: March 2009

ABSTRACTObjective:To evaluate the utility of magnetic resonance cholangiopancreatography (MRCP) in children and to compare MRCP with direct cholangiopancreatography (CP).Materials and Methods:We performed an unblinded, retrospective chart review of 32 children (ages 0–18 years, 17 male) who underwent MRCP between January 2002 and June 2005. MRCP, endoscopic retrograde cholangiopancreatography (ERCP), percutaneous fluoroscopic or intraoperative studies of the pancreatobiliary tree, and clinical outcomes were evaluated.Results:Seventeen (52%) children had MRCP alone, 15 (48%) had both MR and direct CP. MRCP results correlated with other evaluative methods in 14/15 (93%) cases. There was 1 false positive (anomalous pancreatic duct union) and 0 false negatives for anatomic abnormalities. Therapeutic intervention was performed in 7 of 28 children initially evaluated by MRCP (2 sphincter of Oddi dysfunction, 2 choledocholithiasis, 2 primary sclerosing cholangitis, 1 congenital hepatic cysts) and 1 of 4 children initially evaluated by ERCP (primary sclerosing cholangitis). All 17 children initially evaluated by MRCP had no change in clinical status to suggest a missed anatomic lesion or therapeutic opportunity.Conclusions:In this retrospective study, MRCP was sensitive and specific in identifying anatomic abnormalities of the pancreatobiliary tree in children. MRCP should be considered before direct CP to evaluate anatomic abnormalities of the pancreatobiliary tree.
The Effect of Different Topical Negative Pressures on Microvascular Blood Flow in Reperfused Myocardium during Hypothermia
Authors: Lindstedt Sandra , Malmsjö Malin , Ingemansson Richard 
Published: March 2009

Objective Hypothermia is known to limit the extent of myocardial infarction. The earlier hypothermia is applied to an ischemic myocardium, the more tissue can be salvaged. Topical negative pressure (TNP) is known to increase blood flow and stimulate angiogenesis in subcutaneous tissue and skeletal muscle. We have previously shown that a myocardial TNP of −50 mm Hg significantly increases microvascular blood flow in the underlying myocardium in ischemic and reperfused porcine myocardium. The present study was designed to elucidate the effect of different TNP levels on microvascular blood flow in reperfused myocardium during hypothermia. Methods Seven pigs underwent median sternotomy. The microvascular blood flow in the myocardium was recorded before and after the application of −50, −75, −100, −125, and −150 mm Hg using laser Doppler velocimetry. Analysis was performed in the epicardium and at a depth of 6 to 8 mm in the myocardium after 40 minutes of occlusion of the left anterior descending artery followed by cooling to 31°C, and reperfusion for another 20 minutes. Results A TNP of −50 mm Hg significantly increased blood the flow in the epicardium, from 116.7 ± 10.0 PU to 244.5 ± 52.6 PU (*P < 0.05) at 31°C. A TNP of −50 mm Hg significantly increased microvascular blood flow in the myocardium, from 155.0 ± 8.4 PU to 236.7 ± 61.5 PU (*P < 0.05). Conclusions Only a TNP of −50 mm Hg, applied over the left anterior descending artery region in reperfused hypothermic myocardium significantly increased the microvascular blood flow in the epicardium and in the myocardium.
Nasolacrimal Duct Orifice Cysts in Adults: A Previously Unrecognized, Easily Treatable Cause of Epiphora
Authors: DelGaudio John M. , Wojno Ted 
Published: March 2009

AbstractBackground: Epiphora is a common problem evaluated by ophthalmologists and otolaryngologists. It is typically the result of obstruction at some level of the nasolacrimal system, either the canaliculi, sac, or duct. Multiple etiologies exist, including scarring from infection or trauma, tumors, or masses. Cysts of the nasolacrimal duct orifice (dacryocystoceles) in the inferior meatus have been described in neonates, usually presenting as obstructive nasal masses shortly after birth. Nasolacrimal duct orifice cysts have not been described in the adult population in the medical literature.Patients: Three patients were identified with epiphora as a result of cysts in the inferior meatus at the opening of the nasolacrimal duct. All patients presented with constant epiphora and were referred for dacryocystorhinostomy by an ophthalmologist or an otolaryngologist. None of the patients had a previous history of nasolacrimal duct (NLD) surgery. One patient had previous endoscopic sinus surgery for nasal polyps. Cysts were identified by nasal endoscopy of the inferior meatus in all patients.Results: All patients underwent endoscopic resection of the inferior meatus cyst to relieve the obstruction of the NLD. Two procedures were performed under general anesthesia and one under intravenous sedation. All patients had complete relief of epiphora and have had no evidence of recurrence of the symptoms or the cyst in 4 to 10 months follow‐up.Conclusions: NLD orifice cysts are easily correctable causes of epiphora. Routine inferior meatus endoscopy should be routinely performed in patients with epiphora to identify whether on not this pathology is present prior to performing dacryocystorhinostomy.