Biomedical subjects
Publications and source records attributed to K Westphal.
Posterior encephalopathy (PE) is a rare condition with different origins and unknown pathogenesis. We report on a case of a 16-year-old boy with Crohn's disease who developed PE after peridural anesthesia with ropivacain. A possible connection between PE, ropivacain and Crohn's disease is discussed on the basis of the current literature.
OBJECTIVE: Roflumilast is an oral, once-daily phosphodiesterase 4 inhibitor under investigation for the treatment of chronic obstructive pulmonary disease and asthma. In clinical practice, the drug is likely to be co-administered with inhaled bronchodilating beta2-adrenoceptor agonists. Therefore, this study investigated the pharmacokinetic characteristics of roflumilast and its pharmacodynamically active metabolite roflumilast N-oxide when co-administered with orally inhaled salbutamol in healthy subjects. METHODS: In this open, randomized clinical study, 12 healthy male subjects received repeated doses of oral roflumilast 500 microg once daily, orally inhaled salbutamol 200 microg 3 times daily, and a combination of both drugs over 7 days according to a 3-period, changeover design with 14 days washout between treatments. RESULTS: Co-administration of roflumilast and salbutamol did not markedly change roflumilast or roflumilast N-oxide disposition. Point estimates (90% confidence intervals) of area under the curve from 0-24 h (AUC 0-24) and maximum plasma concentration in steady state (Cmax,ss) for roflumilast with salbutamol versus roflumilast alone were 1.05 (0.94, 1.17) and 0.97 (0.84, 1.10); the respective point estimates (90% confidence intervals) for AUC 0-24 and Cmax,ss of roflumilast N-oxide were 0.98 (0.91, 1.06) and 0.98 (0.92, 1.03). Roflumilast co-administration did not alter the pharmacokinetics of steady state salbutamol. The respective point estimates (90% confidence intervals) for AUC 0-6 and Cmax,ss of salbutamol with roflumilast versus salbutamol alone were 1.10 (0.99, 1.21), 1.08 (0.91, 1.28). The combination of both drugs was well tolerated. CONCLUSION: There were no relevant pharmacokinetic interactions between roflumilast and salbutamol at therapeutically effective doses.
The safety of percutaneous tracheostomy in 73 obese patients (body mass index > or = 27.5 kg.m(-2)) in a cohort of 474 adults was studied. Four percutaneous techniques were employed (percutaneous dilational tracheostomy, n = 48; Ciaglia Blue Rhino, n = 157; guide wire dilating forceps, n = 62, translaryngeal tracheostomy, n = 207). The overall complication rate was 43.8% (n = 32) in the obese group compared to 18.2% (n = 73) in the control group (p < 0.001). Seven (9.6%) obese patients suffered life-threatening complications compared to three non-obese patients (0.7%, p < 0.001). Obese patients had a 2.7-fold increased risk for peri-operative complications, and a 4.9-fold increased risk for serious complications. The data suggest that percutaneous tracheostomy in obese patients is associated with a considerably increased risk for peri-operative complications, especially for serious adverse events.
BACKGROUND: Laparoscopic surgery usually requires the use of a pneumoperitoneum by insufflating gas in the peritoneal space. The gas most commonly used for insufflation is carbon dioxide. Increased intra-abdominal pressure causes cephalad displacement of the diaphragm resulting in compressed lung areas, which leads to formation of atelectasis, especially during mechanical ventilation. The aim of this prospective study was to investigate the effect of prolonged intraperitoneal gas insufflation on arterial oxygenation and hemodynamics during mechanical ventilation with and without positive end-expiratory pressure (PEEP). METHODS: Twenty patients undergoing totally endoscopic robot-assisted radical prostatectomy were randomly allocated to one of two groups. In the PEEP group (n = 10) a constant PEEP of 5 cmH(2)O was used, whereas in the ZPEEP group (n = 10) no PEEP was used. RESULTS: Application of PEEP (5 cmH(2)O) resulted in significantly higher P(a)O(2) levels after 3 h (182 +/- 49 vs. 224 +/- 35 mmHg) and 4 h (179 +/- 48 vs. 229 +/- 29 mmHg) of pneumoperitoneum; after desufflation, P(a)O(2) values decreased significantly below preinsufflation values. While there were no significant differences in heart rate, central venous pressure (CVP) and mean arterial blood pressure (MAP) during pneumoperitoneum between both groups, baseline values in CVP and MAP differed significantly between both groups with higher levels in the ZPEEP group. CONCLUSION: The application of a constant positive airway pressure of 5 cmH(2)O preserves arterial oxygenation during prolonged pneumoperitoneum.
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.
As one major link in the chain of survival, early transthoracic (external) cardiac defibrillation is aimed at the termination of ventricular flutter and ventricular fibrillation. Most important to the success of defibrillation is the passage of a defined amount of current through a critical mass of heart muscle. Different transthoracic resistances reduce the effective density of the current within the heart. As for other therapeutic intervention procedures, recommendations for the optimal strength of current to be applied to the fibrillating heart need to be evaluated and defined for therapeutical defibrillation too. Unnecessarily high current density causes damage to the heart and should be prevented. By using biphasic waveforms in contrast to monophasic impulses, the amount of current can be reduced but the same or even higher efficacy is attained. Therefore possible myocardial damage might be clearly reduced. Even with individually altered thoracic impedance effective conversion of cardiac rhythm can be achieved by device-controlled compensation and biphasic waveforms. According to their different mechanisms or origin (electrically induced or spontaneously caused by organic heart disease) the probability of successful conversion of the cardiac rhythm by one single electrical impulse varies. The optimum point in time for defibrillation during resuscitation needs to be redefined. In order to improve comparability, further studies should use standardized definitions for successful defibrillation relating to the resulting cardiac rhythm.
BACKGROUND: Percutaneous dilational tracheostomy (PDT) is considered to be an accepted method in intensive care patients. In 2002 Frova and Quintel described a method of dilation that employed controlled rotation of the PercuTwist dilational device. The goal of the present study was to evaluate the new technique employed by an experienced team. PATIENTS AND METHODS: Prospective, observational clinical study in 54 intensive care patients who required PDT. All tracheostomies were accompanied by bronchoscopic control. Vital parameters and perioperative complications were registered. RESULTS: In all 54 consecutive PercuTwist tracheostomies no severe complications were noted. Accidental tracheal ring fracture was noted in 7 patients while bleeding that needed surgical care occurred in 1 patient. CONCLUSION: The PercuTwist tracheostomy is a safe procedure for intensive care patients. More prospective studies that would compare the PercuTwist tracheostomy with the other PDT methods are necessary.
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.
BACKGROUND: Robotically enhanced telemanipulation is a new powerful tool for minimally invasive procedures that allows totally endoscopic cardiac surgery. Between June 1999 and February 2001, 45 robotically enhanced totally endoscopic coronary artery bypass grafting procedures on the arrested heart were performed at our institution with the use of the da Vinci telemanipulation system (Intuitive Surgical, Inc, Mountain View, Calif). METHODS: In 37 patients a single-vessel totally endoscopic coronary bypass operation was performed. Eight patients had different types of multivessel revascularization with both internal thoracic arteries. The initial conversion rate was 22% and dropped to 5% in the last 20 patients. Two patients required reexploration via median sternotomy. The first 22 patients had excellent graft patency on discharge. The procedural time for single-vessel totally endoscopic bypass was 4.2 +/- 0.4 hours, bypass time was 136 +/- 11 minutes, and aortic crossclamp time amounted to 61 +/- 5 minutes. CONCLUSION: The present data show the feasibility of closed chest single- and double-vessel revascularization, with good clinical results. However, procedural time is prolonged and the complex endoscopic and endoaortic occlusion techniques, as well as the extensive anesthesiologic monitoring, are demanding. The need for conversion to an open procedure diminished after a relatively short learning curve. All postulated benefits of totally endoscopic surgery other than excellent cosmesis must be evaluated in larger cohorts.
Explore the source record for details and available documents.
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.
BACKGROUND: Current options for surgical treatment of coronary single vessel disease range from beating heart procedure without cardiopulmonary bypass via a mini thoracotomy (MIDCAB) to totally endoscopic robot-assisted techniques (TECAB) with cardiopulmonary bypass. Both procedures are associated with considerable stress even before revascularization such as single lung ventilation, temporary coronary occlusion, Luxatio cordis, intrathoracic CO2 insufflation and extended bypass and operating time. The aim of the this study was to document the extent of intraoperative segmental wall motion abnormalities (SWMA) by echocardiography, and to identify variables affecting SWMA. MATERIALS AND METHODS: Forty patients with coronary single vessel disease were included in the study. 16 patients were operated with the MIDCAB technique, and 24 patients underwent TECAB. In both groups of patients sequential transesophageal echocardiograms (2D-loops) were recorded and analyzed. Hemodynamic and electrocardiographic data as well as oxygenation parameters were acquired during echo exams. In both groups of patients mild, but significant perioperative SWMA were identified, which increased in the course of the operation. These SWMA were more pronounced in the TECAB as compared to the MIDCAB group. Independent of operating time these changes disappeared completely until the ends of surgery. Significant hemodynamic or elektrocardiographic modifications were not observed. CONCLUSION: The application of minimally invasive techniques for the surgical treatment of coronary single vessel disease is associated with significant perioperative SWMA. The more pronounced SWMA in the TECAB group may be a consequence of intrathoracic CO2-insufflation. Both techniques can be applied without significant myocardial ischemia, provided that appropriate intraoperative monitoring is performed, and intrathoracic CO2 pressure in TECAB patients is limited.
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.
Health hazards from occupational exposure to trace concentrations of anaesthetic gases cannot be definitively excluded. The aim of the study was to determine the surgeon's occupational exposure to nitrous oxide and sevoflurane during pediatric surgical procedures. Twenty young children (age < 10 years) and five teenagers (age > 10 years) underwent elective abdominal surgery under general inhalational anesthesia. The operating room was equipped with modern air conditioning and waste anesthetic gas scavenger. Levels of both nitrous oxide and sevoflurane were determined in the breathing zone of the surgeon and the anesthesiologist during the operative procedures by means of a direct-reading photoacoustic infrared spectrometer. Both the surgeon and the anesthesiologist were exposed to low concentrations of the inhalational agents used. Exposure to sevoflurane and nitrous oxide was clearly higher during surgery in young children than during operative procedures in teenagers. Nonetheless, the concentrations of these agents were well below the threshold limits of 25 ppm for nitrous oxide and 2 ppm for sevoflurane recommended by the National Institute of Occupational Safety and Health. General anesthesia results in operating room air pollution with inhalational anesthetics. Under modern air conditioning, personnel's occupational exposure is low, and inhalational anesthesia is safe from the standpoint of modern workplace laws and health care regulations. Nonetheless, all efforts must be taken to maintain occupational exposure at this low level.
Gastrointestinal complications after cardiac surgery are associated with a high mortality rate. Because of 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. Within a 1-year period, a total of 1116 patients who had undergone open heart surgery with cardiopulmonary bypass were prospectively studied for gastrointestinal complications. To determine predictive factors, all case histories of the patients were analyzed. Of the 1116 patients, 23 (2.1%) had gastrointestinal complications during the postoperative period, 10 of whom had to undergo subsequent abdominal surgery. Of these 23 patients, 20 died. Early gastrointestinal complications, which occurred mostly on postoperative days 6 or 7, consisted of bowel ischemia or hepatic failure. Late complications were gastrointestinal bleeding, pseudomembranous colitis, cholecystitis, and septic rupture of a spleen. The relative risk for abdominal complications after cardiopulmonary bypass was highly increased in association with (1) a cardiac index less than 2.0 l/min-1/(m2)-1, (2) postoperative onset of atrial fibrillation, (3) emergency surgery, (4) need for vasopressors, (5) need for intraaortic balloon counterpulsation, and (6) need for early redo thoracotomy due to surgical complications. All patients with necrotic bowel disease had elevated serum lactate levels. Furthermore, cardiopulmonary bypass and aortic clamping times were significantly prolonged in patients who developed gastrointestinal complications. A number of predictive factors contribute to the development of gastrointestinal complications after cardiopulmonary bypass surgery. Knowledge of these factors may lead to earlier identification of patients at increased risk and may allow more efficient and earlier interventions to reduce mortality.
The robot device "da Vinci" represents the latest stage in laparoendoscopic surgery. We report the first two cases worldwide of endoscopic Nissen fundoplication with a telemanipulatory robot system in two children, aged 10 and 12 years. In addition to standard monitoring, we used invasive blood pressure monitoring during the 300 min periods of general anesthesia. Arterial blood gas samples were analyzed in short intervals. During surgery, which included 177 and 180 min periods of intraperitoneal insufflation of carbon dioxide, no significant changes of pH, PaO2, PaCO2, etCO2, heart rate, and mean arterial pressure were observed. Body temperature was maintained with an external warming blanket. Extubation was achieved immediately after the end of the operation, and both patients were discharged home on postoperative day 6. Robot-assisted techniques may possibly add significant progress and improvement to laparoendoscopic surgery. Nonetheless, we conclude that, despite our first encouraging results, potential risks of robot-assisted surgery have not yet been definitively defined. Therefore, patients are in need for intensive and even invasive monitoring, unless a larger number of patients has been studied.
Transfusion related acute lung injury (TRALI) is a serious complication of blood transfusion, characterized by non-cardiogenic lung oedema. We describe a case of TRALI due to granulocyte-specific antibodies. The 58-year-old patient received 2 units of fresh frozen plasma following colon surgery and within 30 min the patient developed an acute respiratory distress syndrome. Granulocyte-specific antibodies were found in one of the transfused plasma of a female blood donor who most likely became immunized against granulocyte alloantigens during her three pregnancies.
Elective tracheostomy is widely considered the preferred airway management of patients on long-term ventilation. In addition to open tracheostomy, a number of percutaneous procedures have been introduced during the last two decades, among them techniques according to Griggs (guidewire dilating forceps, or GWDF) and to Fantoni (translaryngeal tracheostomy, or TLT). The aim of the study was to evaluate these two techniques in terms of perioperative complications, risks, and benefits in critically ill patients. A series of 100 critically ill adult patients on long-term ventilation underwent elective percutaneous tracheostomy, either according to the Griggs (n = 50) or Fantoni (n = 50) technique. Tracheostomy was performed under general anesthesia at the patient's bedside. The mean (+/-SD) operating times were short, 9.2 +/- 3.9 minutes (TLT) and 4.8 +/- 3.7 minutes (GWDF) on average. Perioperative complications were noted in 4% of patients during either TLT or GWDF and included massive bleeding, mediastinal emphysema, posterior tracheal wall injury, and pretracheal placement of the tracheostomy tube. With regard to oxygenation, pre- and postoperative arterial oxygen tension divided by the fraction of inspired oxygen (PaO2/FiO2) ratios did not vary significantly, and no perioperative hypoxia was noted regardless of the technique used. We conclude that both TLT and GWDF represent attractive, safe alternatives to conventional tracheostomy or other percutaneous procedures if carefully performed by experienced physicians and under bronchoscopic control.