Pacemaker lead extraction with the laser sheath: results of the pacing lead extraction with the excimer sheath (PLEXES) trial. (9/1305)

OBJECTIVES: The purpose of this study was to evaluate the safety and effectiveness of pacemaker lead extraction with the excimer sheath in comparison to nonlaser lead extraction. BACKGROUND: Fibrotic attachments that develop between chronically implanted pacemaker leads and to the venous, valvular and cardiac structures are the major obstacles to safe and consistent lead extraction. Locking stylets and telescoping sheaths produce a technically demanding but effective technique of mechanically disrupting the fibrosis. However, ultraviolet excimer laser light dissolves instead of tearing the tissue attachments. METHODS: A randomized trial of lead extraction was conducted in 301 patients with 465 chronically implanted pacemaker leads. The laser group patients had the leads removed with identical tools as the nonlaser group with the exception that the inner telescoping sheath was replaced with the 12-F excimer laser sheath. Success for both groups was defined as complete lead removal with the randomized therapy without complications. RESULTS: Complete lead removal rate was 94% in the laser group and 64% in the nonlaser group (p = 0.001). Failed nonlaser extraction was completed with the laser tools 88% of the time. The mean time to achieve a successful lead extraction was significantly reduced for patients randomized to the laser tools, 10.1 +/- 11.5 min compared with 12.9 +/- 19.2 min for patients randomized to nonlaser techniques (p < 0.04). Potentially life-threatening complications occurred in none of the nonlaser and three of the laser patients, including one death (p = NS). CONCLUSIONS: Laser-assisted pacemaker lead extraction has significant clinical advantages over extraction without laser tools and is associated with significant risks.  (+info)

Electromagnetic interference of an external temporary pacemaker during maxillofacial and neck surgery. (10/1305)

Indirect inhibition of an external temporary pacemaker by electrocautery is reported. Before induction of general anesthesia for a hemimaxillectomy and radical neck dissection, a temporary transvenous demand pacemaker was inserted into a patient with a first-degree atrioventricular block and complete left bundle-branch block. Although we provided common precautions to prevent electromagnetic interference by electrocautery, pacing failure still occurred. It was thought to be caused by current dispersing from the active electrocautery electrode. This case suggests that occipital placement of the electrocautery ground plate should be considered during neck surgery in a patient requiring a temporary pacemaker.  (+info)

The use of a channel-cleaning brush for malfunctioning Tenckhoff catheters. (11/1305)

BACKGROUND: Tenckhoff catheter malfunction causes morbidity in some patients on continuous ambulatory peritoneal dialysis (CAPD). Various methods of treatment of malfunction have been described; we report our experience of the use of a channel-cleaning brush for this problem. METHOD: Ten patients on CAPD who developed catheter malfunction were identified. The causes of malfunction were catheter migration in one patient, catheter obstruction due to fibrin and clots in six, probable omental wrapping in one, and pain on draining of PD fluid in two patients. A channel-cleaning brush was manipulated repeatedly in and out of the catheters using aseptic technique and fluoroscopy guidance in an attempt to restore patency or dislodge the catheter to another site. RESULTS: CAPD was successfully re-established after this procedure in eight patients (80%), two catheters were removed from those patients in whom the use of the brush was unsuccessful. CONCLUSION: In this study a channel-cleaning brush was effective and safe in the treatment of Tenckhoff catheter malfunction.  (+info)

Precision, accuracy, and reliability of hemoglobin assessment with use of capillary blood. (12/1305)

BACKGROUND: Previous research has suggested that there may be significant within-subject variability, both site-to-site and over time, in hemoglobin concentrations in capillary blood. OBJECTIVE: This study examined the reliability of the portable hemoglobinometer (PHM) system with use of capillary blood and the implications of errors of the magnitude found for the classification of anemia status in individuals and population groups. The precision and accuracy of the method with use of venous blood were also tested. DESIGN: Three empirical data sets were used to measure reliability, precision, and accuracy of the PHM system [2 from Honduras (n = 87 and 141); 1 from Bangladesh (n = 73)]. Simulation data were used to assess the implications of errors for screening individuals for anemia and to estimate anemia prevalence. RESULTS: High within-subject variability (unreliability) was identified when capillary blood from the left hand was compared with that from the right hand (CV: 6.3%) and when measurements were taken on 4 consecutive days (CV: 7.0%). Reliability was only 69% and 50%, respectively. Precision and accuracy, however, were very high (concordance coefficients of 0.99 and 0.98 and CV < 1%). CONCLUSIONS: The simulation data showed that errors of the magnitude found due to unreliability can lead to misclassification of anemia status in individuals and small biases in anemia prevalence estimates. We recommend replicate sampling to reduce the influence of unreliability in the use of the PHM system with capillary blood.  (+info)

Assessment of public health computer readiness for 2000--United States, 1999. (13/1305)

Computer software, equipment, and other devices that contain embedded microchips that store and process dates may use two-digit years (e.g., 99 for 1999) to reduce data entry burden and save electronic storage space; these devices may not work properly when the year 2000 (Y2K) arrives. Many aspects of health-care delivery, public health surveillance and research, and critical infrastructure components (e.g., utilities and transportation services) depend on vulnerable computers. To ensure that critical public health functions will not be compromised because of Y2K problems, CDC assessed state public health agency readiness for Y2K. This report describes the findings of the assessment, which indicate that state health agencies that responded are substantially ready for Y2K and plan to reach full readiness in 1999.  (+info)

Liability of laryngeal mask airway devices to thermal damage from KTP and Nd:YAG lasers. (14/1305)

We have compared the liability of four laryngeal mask airway (LMA) devices (standard, flexible, intubating and reusable) and a tracheal tube to thermal damage from KTP and Nd:YAG lasers at two power densities used commonly in airway surgery: 570 W cm-2 and 1140 W cm-2. Eighty-five airway devices were tested: 24 standard LMA (silicone-based), 12 flexible LMA (silicone-based, metal wires), 24 disposable LMA (PVC-based), one intubating LMA (silicone and steel-based) and 24 PVC-based tracheal tubes. Comparisons were made during laser strike to eight different targets: the unmarked and marked part of the airway device tube; the unmarked part of the airway device tube after application of blood; the cuff filled with air or methylene blue dye; the unmarked flexible LMA tube on or between the metal wires; and the epiglottic elevator bar of the intubating LMA. The laser strike was continued for 30 s and each target was tested three times. Three different, but identical, impact sites were used for each target. There was no ignition of any airway device with either power density or laser type. The silicone-based LMA were generally more resistant to flaring and penetration than the PVC-based LMA and tracheal tube, but the intubating LMA tube flared more rapidly with the KTP laser, and the disposable LMA cuff was more resistant to penetration. Print markings, blood and the metal wires of the flexible LMA reduced the thermal resistance of the tube. Filling the cuff with methylene blue dye increased the thermal resistance of all airway devices. We conclude that the silicone-based LMA devices were more thermal resistant to KTP and Nd:YAG laser strike than PVC-based devices with the exception of the disposable LMA cuff and the intubating LMA tube.  (+info)

Ventricular fibrillation with small amplitude of activation and its implications for implantable cardioverter defibrillator treatment. (15/1305)

An implantable cardioverter defibrillator (ICD) was implanted in a patient with ventricular fibrillation (VF) related to old myocardial infarction. During VF, amplitude of ventricular activation was small, and the ventricular sensitivity at 1.2 mV failed to detect several small ventricular activations. When the sensitivity was changed to 0.3 mV, both under- and oversensed beats occurred during VF, and at the ventricular sensitivity of 0.15 mV, the undersensed beats disappeared while oversensed beats markedly increased. Defibrillation test was repeated one and four weeks after the implantation, and these inappropriate beats were minimized at the ventricular sensitivity of 0.3 mV. We should pay attention to the amplitude of ventricular activation to avoid possible trouble in ICD therapy.  (+info)

Equipment standards: history, litigation, and advice. (16/1305)

The authors present a concise history of the development of national and international standards for surgical equipment. Standards-writing organizations, surgical and other specialty societies, universities, test houses, and the U.S. government have influenced this process, which is now manifested in complex interactions between national and international standards-writing organizations, and in CE (Conformite Europeene) marks being placed on surgical equipment in the United States and elsewhere. The history of litigation in standards development is also reviewed. Recommendations to maximize patient safety and to help ensure successful, cost-effective defense in litigation for surgeons who use equipment and may suffer its malfunctions are given. Overall, the complicated oversight of surgical equipment standards and the approval process appears to be contributing to the improving and outstanding results of U.S. surgery reported by the U.S. government.  (+info)