[Simulator model for ultrasound-guided pericardiocentesis : Construction manual and practical evaluation]. / Simulationsmodell für ultraschallgestützte Perikardiozentese : Bauanleitung und praktische Evaluation.

An important challenge in learning ultrasound-assisted interventions, such as pericardiocentesis, is the navigation of the needle in a three-dimensional space on the basis of a two-dimensional image. In order to learn this in vitro realistic simulators are required. We manufactured a model which allows simulation of pericardiocentesis on the basis of ballistic gelatin (12.6%, 250 Bloom). Furthermore, the pericardiocentesis model was subjectively evaluated by 37 anesthetists in a pre-post design. The models used proved to be technically simple to manufacture, hard wearing and realistic. They are therefore regularly used in our hospitals to learn ultrasound-assisted interventions.

[Reintubation using the C-MAC videolaryngoscope. Implementation in patients with difficult airways initially managed with in situ laryngeal tubes]. / Umintubation mithilfe des C-MAC-Videolaryngoskops. Durchführung bei Patienten mit schwierigem Atemweg und einliegendem Larynxtubus.

BACKGROUND: Securing the airway with supraglottic airway devices, such as a laryngeal tube, is a regular component of most difficult airway management algorithms. It is further recommended that in emergency medicine rescuers less skilled in endotracheal intubation should use supraglottic airways as a first line device. Exchanging the laryngeal tube with an endotracheal tube can be performed with video-assisted laryngoscopy as described below. MATERIAL AND METHODS: A total of 20 adult patients with airways managed using laryngeal tubes due to actual or anticipated difficult intubation underwent endotracheal intubation using the C-MAC videolaryngoscope. After deflating the cuffs of the laryngeal tube, seeking out the glottis was done by following the constructional landmarks of the laryngeal tube, considering concordance with anatomical landmarks of the human airway. In cases of failed video-assisted endotracheal intubation, the laryngeal tube that was still in situ was reinflated to re-establish ventilation of the lungs. RESULTS: In 19 out of the 20 patients the laryngeal tube could be exchanged for an endotracheal tube with the video-assisted technique described. In one patient no laryngeal structures could be identified (Cormack and Lehane grade IV) even with the C-MAC videolaryngoscope and ventilation was continued via the laryngeal tube. No complications related to the video-assisted intubation technique were observed. CONCLUSIONS: The C-MAC videolaryngoscope is a mobile system which facilitates endotracheal intubation in patients with a difficult airway and a laryngeal tube in place. It is not only possible but recommended to leave the laryngeal tube in situ as a back-up when videolaryngoscopy fails.

[Valvular heart disease: anesthesia in non-cardiac surgery]. / Herzklappenerkrankungen : Anästhesie bei nichtkardiochirurgischen Eingriffen.

The probability of treating patients with valvular heart disease during non-cardiac surgery increases with the age of the patient. The prevalence of valvular heart disease is approximately 2.5% and increases further in the patient group aged over 75 years old. Patients with valvular heart disease undergoing non-cardiac surgery have an increased perioperative cardiovascular risk depending on the severity of the disease. Knowledge of the hemodynamic alterations and compensation mechanisms which accompany diseases of the valve apparatus is essential for a suitable treatment of patients with such pre-existing diseases. The most common valvular heart diseases lead to volume (mitral valve insufficiency) or pressure load (aortic stenosis) of the left ventricle and in the case of mitral stenosis to a pressure load on the left atrium. Depending on the underlying disease and the type of surgery planned a corresponding choice of anesthesia procedure and medication must be made. In the present review article the pathophysiology of the relevant valvular heart diseases and the implications for perioperative anesthesia management will be presented. An individually tailored extended perioperative monitoring allows hemodynamic alterations to be rapidly recognized and adequately treated.

[Laryngeal tube II : alternative airway for children?]. / Larynxtubus II : Alternativer Atemweg bei Kindern?

Difficult airway situations both expected and unexpected, present major challenges to every anesthesiologist, especially in pediatric anesthesia. However, the integration of extraglottic airway devices, such as the laryngeal mask, into the algorithm of difficult airways has improved the handling of difficult airway situations. A device for establishing a supraglottic airway, the laryngeal tube (LT), was introduced in 1999. The LT is an extraglottic airway designed to secure a patent airway during either spontaneous breathing or controlled ventilation. The design of the device has been revised several times and a further development is the LTS II/LTS-D, which provides an additional channel for the insertion of a gastric drain tube. This article reports on the successful use of the LTS II in 12 children aged from 2 days to 6 years when endotracheal intubation, alternative mask or laryngeal mask ventilation failed. Use of the LTS II was associated with a high level of success, securing the airway when other techniques had failed. The potential advantage of the LTS II over the standard LT is an additional suction port, which allows gastric tube placement and can be used as an indirect indicator of correct placement. With a modified insertion technique using an Esmarch manoeuvre, placement was simple and fast to perform. In emergency situations when direct laryngoscopy fails or is too time-consuming the LTS II tube is recommended as an alternative device to secure the airway. As with all extraglottic airway devices, familiarity and clinical experience with the respective device and the corresponding insertion technique are essential for safe and successful use, especially in emergency situations.

[Gone with the wind or... Fate of scientific articles presented at large anesthesia congresses--an update]. / Vom Winde verweht oder... "Schicksal" wissenschaftlicher Beiträge auf großen Anästhesiekongressen--ein Update.

BACKGROUND: The goal of the present study was to evaluate the publication rate of abstracts presented during the German Anesthesia Congress (Deutscher Anästhesiecongress, DAC) and the meeting of the European Society of Anesthesiologists (ESA) in the years 2000 and 2005 in Medline listed journals (http://www.ncbi.nlm.nih.gov/pubmed). In addition, the respective impact factors of the journals in which the articles were published were evaluated (http://www.isiknowledge.com). METHODS: All abstracts of free papers and posters presented at the DAC and ESA from the years 2000 and 2005 were included into the study. The presence of authors and the topics of abstracts in the literature were analyzed by a Medline based inquiry over a time period of 5 years. The search was based on the last name and initials of authors and when these could not be identified in Medline the search was extended by keywords of relevant topics of the abstract. Umlauts "ä/ö/ü" were replaced by "ae/oe/ue" and "ß" was replaced by "ss". Only original papers were included in this analysis. Once an original paper was found the impact factor of the journal in that year was identified. RESULTS: A total of 465 abstracts from the DAC 2000, 378 abstracts from the DAC 2005, 644 abstracts from the ESA 2000 and 720 abstracts from the ESA 2005 were included. Of the abstracts from the DAC 2000, 183 (39%) were published in Medline listed journals, 179 (47%) from DAC 2005, 218 (34%) from ESA 2000 and 233 (32%) from ESA 2005. The ESA abstracts were published in English more often than the DAC abstracts (ESA 2000: 95%; ESA 2005: 95%; DAC 2000: 78%; DAC 2005: 86%). While the publication rate after the ESA remained nearly unchanged between 2000 and 2005, the publication rate after the DAC increased by about 7%. The average impact factors of the publications were 1.777 (DAC 2000), 2.836 (DAC 2005), 1.825 (ESA 2000) and 2.36 (ESA 2005). Independent of the congress (DAC or ESA) where the abstract was presented, most articles were published in the journal Anesthesia & Analgesia. CONCLUSION: In the year 2005 more abstracts of the DAC were published in Medline listed papers than in 2000. When comparing the number of abstracts published in Medline listed journals, more abstracts of the DAC were published compared to abstracts of the ESA. The increase in papers written in English after abstract presentation on the DAC is mostly due to the wider readership which can be reached with manuscripts in the English language. Besides a larger readership, English journals often also have a higher ranked impact factor. This analysis does not claim to be a complete registration of all published abstracts due to the limitation on Medline listed journals and publications in other journals were not rated. Medline was selected because of the widespread and international use of this database.

[Direct laryngoscopy or C-MAC video laryngoscopy? Routine tracheal intubation in patients undergoing ENT surgery]. / Direkte Laryngoskopie oder C-MAC-Videolaryngoskopie? Routineintubation von Patienten in der HNO-Heilkunde.

BACKGROUND: Previous studies have shown that video laryngoscopy enhances laryngeal view in patients with apparently normal and difficult airways. The utility of the novel, portable, battery-powered C-MAC video laryngoscope is as yet unproven. It was hypothesized that in routine patients undergoing ENT surgery, the rate of glottic views considered unsatisfactory, i.e. Cormack and Lehane grades IIb, III, and IV, could be significantly reduced with the C-MAC video laryngoscope compared to direct laryngoscopy. METHODS: Following ethical approval and sample size estimates 108 consecutive patients undergoing ENT surgery under general anesthesia were studied. First, direct laryngoscopy was performed with the naked eye. The best view obtained was graded by the first anesthesiologist without looking at the video monitor. A second anesthesiologist blinded to the laryngeal view obtained under direct laryngoscopy graded the laryngeal view on the video monitor. Endotracheal intubation using Ring-Adair-Elwyn (RAE) tracheal tubes was then attempted under video-aided visualization. The tubes were not reinforced with a stylet. The C-MAC video laryngoscopy system (Karl Storz, Tuttlingen, Germany) is a novel device that can be used with Macintosh laryngoscope blades in different sizes. A camera and light source are located recessed from the tip of the blade. The camera unit sits in a handle attached to the laryngoscope blade and is connected by a wire to a TFT video monitor. It allows for both direct and indirect laryngoscopy and the low profile of the original British Macintosh blades may prove advantageous in patients with limited mouth opening. RESULTS: A total of 108 patients were enrolled in the study but for various reasons only 94 completed the study (post hoc power 97%). In 89 patients a size 3 Macintosh laryngoscope was used while a size 4 blade was used in the remaining 5 patients. With direct laryngoscopy the glottic view was considered unsatisfactory in 40 patients (42%), but this was the case in only 15 patients (16%) when video laryngoscopy was used (p<0.0001). Endotracheal tube placement was successful in all but one patient where the Bonfils intubation fiberscope needed to be employed. No complications related to the C-MAC system were observed. CONCLUSIONS: Compared to direct laryngoscopy with a Macintosh laryngoscope blade in unselected patients undergoing ENT surgery and thus patients more susceptible to an unexpected difficult airway than a general patient population, the mobile C-MAC video laryngoscope significantly enhanced laryngeal view. Using RAE tracheal tubes seems to compensate the unfavorable deviation of optical and anatomical axes when indirect laryngoscopy is performed with the C-MAC system.

[Special features of laparoscopic operations from an anesthesiologic viewpoint: a review]. / Besonderheiten bei laparoskopischen Operationen aus anästhesiologischer Sicht: Eine Ubersicht.

The value of laparoscopic procedures has increased over the last decade. Many patients undergoing laparoscopic surgery also have coexisting diseases. The hemodynamic effects of intraperitoneal carbon dioxide insufflation depend on the extent of intraperitoneal pressure, severity of preexisting cardiopulmonary diseases, volume state of the patient and alterations of acid-base balance due to a capnoperitoneum. In addition to endocrinologic reactions, patient positioning also affects hemodynamic parameters. In high risk patients extended cardiopulmonary monitoring with an arterial line and repeated blood gas analysis is recommended intraoperatively, in addition to assessment of end-expiratory CO(2). In this patient group the intra-abdominal pressure should be maintained in the range of 5-7 mmHg.

[Coronary artery bypass grafting in conscious patients: a procedure with a perspective?]. / Koronare Bypasschirurgie am wachen Patienten : Ein Verfahren mit Zukunft?

Patients undergoing coronary artery bypass grafting increasingly show severe co-morbidities, which can negatively affect the outcome. Recent developments in cardiac surgery have therefore focused on minimizing the invasiveness of the procedure by revascularization on the beating heart without cardiopulmonary bypass, and by reducing surgical trauma using smaller surgical incisions. Progress in minimally invasive cardiac surgery has led to minimally invasive anesthesia, i.e. using high thoracic epidural anesthesia as the sole technique in the conscious patient (awake coronary artery bypass grafting, ACAB). Published data on ACAB procedures in smaller cohorts have demonstrated that the procedure is safe. Significant complications occurred in 7.1% of patients. A particular cause of concern during ACAB surgery is the development of spinal epidural hematoma the risk of which has been estimated to be as high as 1:1,000. A thorough risk-benefit analysis has therefore to be made. Currently, ACAB surgery remains limited to few specialized centers and highly selected patients.

Structure of the fifth EGF-like domain of thrombomodulin: An EGF-like domain with a novel disulfide-bonding pattern.

The structure of the fifth EGF-like domain (residues Q387 to E426) of thrombomodulin (TMEGF5) has been determined by two-dimensional NMR. TMEGF5 binds to thrombin with a Ki of 1.9 microM and has been shown to have a novel disulfide bonding pattern in a fully active fragment of TM. In EGF, the disulfide bonding pattern is (1-3,2-4, 5-6), while TMEGF5 has an uncrossed (1-2,3-4,5-6) pattern. The structure of this novel domain, determined from 483 NOE-derived distance restraints, appears to have diverged from the common EGF-like structure. Superposition of the 14 lowest-energy structures of TMEGF5 gives an overall r.m.s.d. of 1.09 A for the backbone atoms. The central two-stranded beta-sheet common to all EGF-like domains is not present in TMEGF5. The A loop, residues C390 to C395, is twisted away from interacting with the B loop, residues C399 to C407, as in EGF, and is close to the C loop, residues C409 to C421. This twist causes the N and C termini to be closer together in TMEGF5 than in EGF. Most of the residues that are important for activity lie on one face of the molecule, which is likely to be the thrombin-binding surface of the domain. The structure of the C loop within the domain, which is a beta-hairpin similar to EGF, is similar to the structure of a synthetic version of the loop bound to thrombin as determined by transferred NOE experiments. Despite the similarity in the structures of the loops, the residues immediately following C421 are in different positions in the two structures suggesting that these "tail" residues may change conformation upon thrombin binding.

Comparison of continuous background infusion plus demand dose and demand-only parturient-controlled epidural analgesia (PCEA) using ropivacaine combined with sufentanil for labor and delivery.

BACKGROUND: Using ropivacaine combined with sufentanil, we determined the analgesic efficacy of parturient-controlled epidural analgesia (PCEA) with or without (demand-only PCEA) continuous background infusion in reducing labor pain in 66 parturients. METHODS: After placement of the epidural catheter and administration of an initial bolus containing ropivacaine 16 mg and sufentanil 10 microg, parturients were prospectively randomized into two groups. The PCEA solution consisted of ropivacaine 0.16% plus sufentanil 0.5 microg/mL. Parturients with PCEA plus continuous background infusion received 4 mL/h plus an hourly maximum of three 4-mL boluses on demand (lock-out time 20 min); parturients with demand-only PCEA received an hourly maximum of four 4-mL boluses (lock-out time 15 min) of anesthetic solution. Pain scores (VAS 0-100 mm), drug doses administered, duration of labor, sensory and motor epidural block characteristics, maternal satisfaction, neonatal outcome and adverse events were determined. RESULTS: Both regimens provided excellent parturients' satisfaction and pain relief. However, periods of VAS scores>40 mm during all stages of labor were significantly more frequent in parturients receiving demand-only PCEA (22.4%) compared to parturients receiving PCEA plus continuous background infusion (7.5%, P=0.0011). Drug doses administered, duration of PCEA, labor and delivery, epidural block characteristics, neonatal outcome and adverse events did not differ between groups. CONCLUSION: Under the conditions of the study, PCEA plus continuous background infusion was more effective than demand-only PCEA in treating labor pain without increasing consumption of anesthetic solution.

Synthesis, activity, and preliminary structure of the fourth EGF-like domain of thrombomodulin.

The fourth EGF-like domain of thrombomodulin (TM4), residues E346-F389 in the TM sequence, has been synthesized. Refolding of the synthetic product under redox conditions gave a single major product. The disulfide bonding pattern of the folded, oxidized domain was (1-3, 2-4, 5-6), which is the same as that found in EGF protein. TM4 was tested for TM anticoagulant activity because deletion and substitution mutagenesis experiments have shown that the fourth EGF-like domain of TM is essential for TM cofactor activity. TM4 showed no TM-like activity in two assay systems, both for inhibition of fibrin clot formation, and for cofactor activity in thrombin activation of protein C. A preliminary structure of TM4 was determined by 2D 1H NMR from 519 NOE-derived distance constraints. Distance geometry calculations yielded a single convergent structure. The structure resembles the structure of EGF and other known EGF-like domains but has some key differences. The central two-stranded beta-sheet is conserved despite the differences in the number of amino acids in the loops. The C-terminal loop formed by the disulfide bond between C372 and C386 in TM4 is five amino acids longer than the analogous loop between C33 and C42 of EGF protein. This loop appears to have a different fold in TM4 than in EGF protein. The loop forms the two outside strands of a broken, irregular tri-stranded beta-sheet, and amino acids H384-F389 lie between the two strands forming the middle strand of the sheet. Thus, although the C-terminus of EGF protein forms one of the outside strands of a tri-stranded antiparallel sheet, the C-terminus of TM4 forms the inside strand of an irregular tri-stranded parallel-anti-parallel sheet. The residues D349, E357, and E374, which were shown to be critical for cofactor activity by alanine scanning mutagenesis, all lie in a patch near the C-terminal loop, and are solvent accessible. The other critical residues, Y358 and F376, are largely buried and appear to play essential structural rather than functional roles.

Thrombin inhibition by cyclic peptides from thrombomodulin.

Peptides corresponding to the loop regions of the fourth, fifth, and sixth epidermal growth factor (EGF)-like domains of thrombomodulin (TM) have been synthesized and assayed for thrombin inhibition, as indicated by both inhibition of thrombin-mediated fibrinogen clotting and inhibition of the association of thrombin with TM that results in protein C activation. Peptides from the fifth EGF-like domain showed significant inhibition of fibrinogen clotting and protein C activation, whereas peptides from the fourth and sixth EGF-like domains were weak inhibitors in both assays. Two structural features were important for inhibitory potency of the peptides from the fifth EGF-like domain: cyclization by a disulfide bond and attachment of the "tail" amino acids C-terminal to the disulfide loop. Linear control peptides did not significantly inhibit clotting or protein C activation. The C-terminal loop alone, the "tail" peptide, or a mixture of the two were at least 10-fold less potent inhibitors of clotting or protein C activation. A more constrained peptide analog was designed by deletion of an isoleucine within the C5-C6 disulfide loop, TM52-1 + 5C. This analog was a better inhibitor in both assay systems, having a Ki for protein C activation of 26 microM.

Hemodynamics and gas exchange during carbon dioxide insufflation for totally endoscopic coronary artery bypass grafting.

BACKGROUND: In addition to single-lung ventilation (SLV), positive-pressure CO2 insufflation is mandatory for totally endoscopic coronary artery bypass grafting. Studies on the effects of unilateral CO2 insufflation on hemodynamics produced controversial results, and bilateral insufflation has not been studied to our knowledge. The present study sought to investigate hemodynamics and gas exchange during unilateral and bilateral CO2 insufflation in patients who underwent totally endoscopic coronary artery bypass grafting. METHODS: Eleven hemodynamic and gas exchange variables were monitored during 22 totally endoscopic coronary artery bypass grafting procedures with unilateral (n = 17) or bilateral (n = 5) CO2 insufflation at a pressure of 10 to 12 mm Hg. Data were obtained at baseline with double-lung ventilation, after institution of SLV, during insufflation, after cardiopulmonary bypass during SLV, and after return to double-lung ventilation. RESULTS: Arterial oxygen tension decreased significantly during SLV, whereas the peak inspiratory pressure increased. In addition, central venous pressure and heart rate increased significantly during insufflation, but mean arterial pressure remained unchanged. Although the end-tidal CO2 pressure did not change, arterial carbon dioxide tension increased progressively to a maximum of 44.6 +/- 5.9 mm Hg during unilateral insufflation, and 55.7 +/- 14.6 mm Hg during bilateral insufflation (p < 0.05 versus baseline and between groups). Mixed venous oxygen saturation declined during SLV regardless of CO2 insufflation and recovered to baseline once double-lung ventilation was restarted. Left and right ventricular ejection fractions remained unaltered. No patient required inotropic or vasopressor support. CONCLUSIONS: Carbon dioxide insufflation for totally endoscopic coronary artery bypass grafting with SLV had no adverse effects on hemodynamics. In contrast to a moderate increase of arterial carbon dioxide tension during unilateral insufflation, markedly elevated arterial carbon dioxide tension levels remain a cause of concern during bilateral insufflation.

Early experiences of robotic surgery in children.

BACKGROUND: Laparoscopic surgery using a robotic system (Da Vinci) was recently introduced into surgical practice for adult patients. To investigate the feasibility of this system in pediatric surgery, laparoscopic fundoplication (Thal and Nissen), cholecystectomy, and bilateral salpingo-oophorectomy were performed. METHODS: Eleven children with a mean age of 12 years (range, 7-16 years) underwent either laparoscopic anterior partial fundoplication (Thal, n = 8) or Nissen fundoplication (n = 3) for correction of gastroesophageal reflux disease in the presence of uncontrolled symptoms of regurgitation and pulmonary infection. Two children underwent laparoscopic cholecystectomy due to symptomatic cholecystolithiasis. One child underwent bilateral salpingo-oophorectomy due to a gonadoblastoma. RESULTS: Mean operating time for fundoplication was 146 min (range, 105-180 min), the operating times for cholecystectomy were 150 and 105 min, and that for salpingo-oophorectomy was 95 min. No complications were registered during either the robotic procedures or the postoperative courses. CONCLUSIONS: Compared to conventional laparoscopy, the three-dimensional high-quality vision, advanced instrument movement, and improved ergonomic position of the surgeon appear to enhance surgical precision. Robotic surgery in children using the Da Vinci system seems to be feasible and safe. However, the technique is limited due to the fact that instruments adapted to the size of small children are not available. Furthermore, the high costs and prolonged system setup are disadvantages.

Prolonged intraperitoneal versus extraperitoneal insufflation of carbon dioxide in patients undergoing totally endoscopic robot-assisted radical prostatectomy.

BACKGROUND: Extraperitoneal laparoscopic prostatectomy is an alternative to the intraperitoneal method. However, the effects of extraperitoneal carbon dioxide (CO2) insufflation on hemodynamics and respiratory data have not been adequately studied. This study compared the effects of prolonged intra- and extraperitoneal CO2 insufflation on hemodynamics and gas exchange. METHODS: For this study, 20 patients were assigned to receive totally endoscopic robot-assisted radical prostatectomy (TERP) via the intra- or extraperitoneal approach. Hemodynamic parameters and respiratory data were obtained during 8 h of insufflation and analyzed for statistical differences. RESULTS: With both insufflation methods, arterial CO2 pressure increased rapidly, reaching higher levels with extraperitoneal insufflation. Therefore, patients managed with extraperitoneal insufflation required a significantly higher minute ventilation. Heart rate and central venous pressure increased in both groups, whereas mean arterial blood pressure and pH decreased. CONCLUSIONS: Prolonged intra- and extraperitoneal CO2 insufflation for TERP resulted in significant, but mostly clinically unimportant, hemodynamic alterations. Carbon dioxide absorption was more pronounced with extraperitoneal insufflation.

Totally endoscopic Nissen fundoplication with a robotic system in a child.

The Da Vinci robot device represents the latest advance in laparoendoscopic surgery. We report the case of an endoscopic Nissen fundoplication performed with the aid of a telemanipulation robot system in a 10-year-old girl. To our knowledge, this is the first such case to be reported. In addition to standard monitoring, we used invasive blood pressure monitoring during the 282-min period of general anesthesia. Arterial blood gas samples were analyzed at short intervals. During surgery, which included a 172-min period of intraperitoneal insufflation of carbon dioxide (CO2), no significant changes were observed in PH, arterial oxygen pressure (PaO2), arterial carbon dioxide pressure (PaCO2), heart rate, or mean arterial pressure. Body temperature was maintained with an external warming blanket. Total intravenous anesthesia with continously administered propofol, remifentanil, and mivacurium for continous muscle relaxation allowed extubation immediately after skin closure. The girl was discharged from hospital on postoperative day 6. Robot-assisted techniques have the potential to significantly improve the performance of laparoendoscopic surgery. However, despite our encouraging first results, the potential risks of robot-assisted surgery have not yet been definitively established. Therefore, patients submitted to this type of procedure require intensive and even invasive monitoring.

Routine microbiological screening in septic patients in a cardiac surgical intensive care unit.

INTRODUCTION: Patients in a surgical intensive care unit (ICU) have a high incidence of nosocomial infections which often lead to septic shock and death. Since specific antibiotic treatment is often difficult, it is recommended that routine nose/throat swabs be obtained in order to have a better idea of the causative agent when a systemic inflammatory response occurs in a given patient. MATERIALS AND METHODS: In 1435 patients in a cardiac surgical ICU, routine nose/throat swabs were taken thrice a week and tested for microorganisms and systemic inflammation. Blood cultures were also obtained. Antibiotic treatment was given to cover the microbes from the nose/throat swabs. Alternatively, an empirical antibiotic therapy was given to patients whose swabs had tested negative. RESULTS: Of the 86 patients with systemic inflammation, 29 had blood cultures positive for microbes. Of these, 18 received a specific antibiotic therapy based on their positive nose/throat cultures prior to the return of the blood cultures from the laboratory. However, only 11 patients tested positive for the same microbes on routine swabs and blood cultures. While positive routine swabs are quite specific to sepsis when there is a systemic inflammatory response, routine swabs are not a suitable screening tool due to their low sensitivity. CONCLUSION: Routine nose/throat swabs led to earlier specific antibiotic treatment in only 22 % of patients with clinical signs of systemic inflammation. In 36 % of cases, the organisms detected in the routine swabs and blood cultures were not identical. Hence, we believe that routine swabs are of limited value in instituting earlier, specific antibiotic therapy in septic patients.

Transesophageal echocardiography or fluoroscopy during port-access surgery?

INTRODUCTION: In Port-Access cardio-surgical procedures, both intraoperative transesophageal echocardiography (TEE) and fluoroscopy can be used for placement of the catheters and cannulae needed for cardiopulmonary bypass. Our study sought to clarify whether it is possible to rely exclusively on TEE for catheter placement without increasing the risk for the patient. MATERIALS AND METHODS: Forty patients underwent cardiac surgery with the Port-Access system. Fluoroscopy as well as TEE were used for placement of the transjugular and transfemoral catheters required for cardiopulmonary bypass. The time required for fluoroscopy was recorded, as were any complications during cannulation and cardiopulmonary bypass. RESULTS: The average fluoroscopy time was 10.7 +/- 12.1 min. Fluoroscopy time required for placement of the coronary sinus and pulmonary vent catheters could be reduced to zero early in the course of the study. Once we had gained enough experience with TEE, fluoroscopy for placement of the transfemoral catheters was also no longer necessary. During cannulation, 3 patients suffered complications requiring immediate surgical intervention. These complications were all diagnosed by TEE. CONCLUSION: Our data suggest that positioning of the coronary sinus and the pulmonary vent catheters is safe and practicable with TEE alone. Nonetheless, if TEE imaging is poor or fails, fluoroscopy has still a place in Port-Access surgery and should always be available intraoperatively.

Abdominal complications after cardiac surgery.

OBJECTIVE: Abdominal complications after cardiac surgery are associated with a high mortality rate. Due to the absence of early specific clinical signs, diagnosis is often delayed. The present study seeks to determine predictive risk factors for subsequent gastrointestinal complications after cardiosurgical procedures. METHODS: Within 12 months, all patients (n = 1,116) who had undergone open heart surgery with cardiopulmonary bypass at our institution were studied for abdominal complications. To determine predictive factors, all case histories of the patients were analysed. RESULTS: Abdominal complications occurred in 23 (2.1%) patients during the postoperative intensive care unit (ICU) stay, ten of whom had to undergo subsequent abdominal surgery. Of these 23 patients, 20 died. Early complications occurred most likely on postoperative days 6 and 7, consisting of bowel ischaemia or hepatic failure. Late complications consisted of gastrointestinal bleeding, pseudomembraneous colitis, cholecystitis and septic rupture of a spleen. The relative risk for abdominal complications after cardiopulmonary bypass was highly increased in association with a cardiac index less than 2.0 l/min-1/(m2)-1 (22.1-fold), postoperative onset of atrial fibrillation (16.6-fold), emergency surgery (10.7-fold), need for vasopressors (10.1-fold), need for intra-aortic balloon counterpulsation (8.6-fold), and the need for re-exploration within the first 24 hours (8.4-fold). All patients with necrotic bowel disease had elevated serum lactate levels. Furthermore, both cardiopulmonary bypass and aortic clamping times were significantly prolonged in patients who developed gastrointestinal complications. CONCLUSIONS: A number of predictive factors has been described to contribute to the development of abdominal complications subsequently after cardiac surgery on cardiopulmonary bypass. Knowledge of these factors may lead to earlier identification of patients at increased risk and may allow for more efficient and earlier interventions.

A study of aniseikonia and Knapp's law using a projection space eikonometer.

PURPOSE: Knapp's Law, which states that anisometropias due to varying abnormal axial lengths between eyes would not result in inequality in relative retinal image size, provided the correcting spectacle lens was placed at the far point of the eye, has been shown to fall short in clinical practice in several studies using "direct comparison eikonometry". To test these findings using space eikonometry and to further elucidate this Law's clinical applicability, the following study was conducted. METHODS: Thirteen patients with suspected axial anisometropia of at least 4 Diopters were identified, selected and examined. Cycloplegic refraction, A-scan ultrasonic ocular biometry and Essilor Projection Space Eikonometry were performed. RESULTS: Ten of the thirteen patients had their anisometropia due primarily to ocular axial length differences. Of these ten, seven (70%) had detectable levels of aniseikonia and 3 (30%) demonstrated no aniseikonia. The other three patients whose aniso-metropia was due to combined axial and refractive components, all had aniseikonia. CONCLUSION: As a geometric optics theory, Knapp's Law stands on its own merits. However, in clinical practice, reduction in retinal element density in high myopia limits its applicability. Such patients often do have significant aniseikonia which can produce ocular referable complaints and/or interfere with binocular vision.