Anesthesia breathing circuits protected by the DAR Barrierbac S breathing filter have a low bacterial contamination rate.

PURPOSE: In order to reuse the same anesthesia breathing circuit for more than one patient, it has been proposed to add a breathing filter between the Y-piece and the artificial airway. The purpose of this study was to evaluate the in vivo bacterial filtration efficacy of an anesthesia filter in a usual clinical anesthesia setting. METHODS: A sterile DAR Barrierbac S breathing filter was inserted at the Y-piece of a sterile single-use anesthesia breathing circuit before induction of general anesthesia. At the end of anesthesia, the breathing circuit connector of the filter and of the endotracheal tube connector were cultured separately on growth media (chocolate and blood agar). These were incubated for 48 hr and bacterial identification was conducted using standard methods. RESULTS: Bacterial cultures were negative on both sides of the filter membrane of 1842 of the 2001 filters studied. Cultures were positive on the patient side of 104 filters. In two of those, the same bacteria were found on both the circuit side and the patient side of the filter. Therefore these data indicate a clinical effectiveness of 99.9% (confidence interval, CI 95%, 99.6-99.998%), and an in vivo filtration efficacy of 98.08% (CI 95%, 92.54-99.67%). CONCLUSION: Using the upper limit of the CI, it can be assumed that the practice of using a sterile DAR Barrierbac S breathing filter for every patient while reusing the anesthesia breathing circuit would result in a cross contamination rate of the breathing circuit lower than once every 250 cases.

Esophageal and tracheal distortion by the Esophageal-Tracheal Combitube: a cadaver study.

PURPOSE: To understand the anatomical relationships of the Esophageal-Tracheal Combitube (ETC) with the larynx, pharynx, esophagus and trachea. METHODS: An extensive dissection of the neck and thorax of a 70-yr-old caucasian male cadaver was done to expose the larynx, pharynx, trachea and esophagus. The ETC was inserted following the manufacturer's recommendations. Effects of the ETC on the surrounding structures were observed with the ETC first inserted in the esophagus and then, in the trachea. RESULTS: When inserted in the esophagus, the ETC produced marked bulging of the anterior wall of the esophagus and anterior displacement (4.5 cm) of the trachea. Inflation of the distal cuff of the ETC produced distension of the esophagus. When inserted in the trachea, the ETC also caused anterior protrusion. CONCLUSION: Protrusion of the anterior wall of the esophagus and distension resulting from inflation of the distal cuff could lead to esophageal injuries. These observations may explain the previously reported complications associated with the use of the ETC.

Complications associated with the use of the Esophageal-Tracheal Combitube.

PURPOSE: To report four cases of subcutaneous emphysema, pneumomediastinum and pneumoperitoneum associated with the use of the Esophageal-Tracheal Combitube (ETC) during prehospital management of cardiac arrest. CLINICAL FEATURES: Between September 1994 and April 1996, 1139 patients were resuscitated with the ETC and the semiautomated external defibrillator as part of the CPR protocol for prehospital management of cardiac arrest by basic emergency medical technicians. Eight of these patients presented with subcutaneous emphysema. Four of them, declared dead after arrival in the emergency room (ER), had autopsy studies. In two, autopsy revealed large (6 and 6.5 cm respectively) longitudinal transparietal lacerations of the anterior wall of the oesophagus. Multiple superficial lacerations of the oesophagus were also present in another patient, while no lesion of the airway or the oesophagus was found in the last patient. CONCLUSION: These cases suggest that subcutaneous emphysema, pneumomediastinum and pneumoperitoneum might be complications associated with the use of the ETC. At least in two cases, oesophageal laceration appears to be the mechanism by which these complications occurred.

Selenium-vitamin E supplementation in infertile men. Effects on semen parameters and micronutrient levels and distribution.

In order to verify the hypothesis that selenium (Se) and vitamin E (Vit E) could improve male fertility, nine oligoasthenoteratozoospermic men were supplemented for a period of 6 mo with Se and Vit E. Compared to the baseline period (presupplementation) of 4 mo, statistically significant increases were observed for Se and Vit E levels, sperm motility, percent live, and percent normal spermatozoa. These improvements are likely to be "supplementation-dependent," since all of the parameters returned to baseline values during the posttreatment period. None of the couples reported a pregnancy during the study. The HPLC analysis conducted on the serum of one of the patients showed the existence of at least six different Se-containing peaks, whose Se content was affected by supplementation. The mechanism(s) involved in these improvements of semen parameters is presently under investigation.

Low-dose sufentanil in major surgery.

The purpose of this study was to assess the efficacy of sufentanil 1 micrograms.kg-1 during N2O-O2 and intermittent isoflurane anaesthesia in major non-cardiac surgery. Thirty-one patients (18 females, 13 males; mean age 47 yr), undergoing cholecystectomy received a 1 microgram.kg-1 bolus of sufentanil before the induction of anaesthesia with thiopentone. On average, three sufentanil increments were administered, to a total (bolus + maintenance) dose of 1.5 micrograms.kg-1. Cardiovascular stability was not achieved in eleven patients who then were given isoflurane. The arterial pressure decreased after sufentanil (P less than 0.05), reaching a nadir (mean 108/65 mmHg, heart rate 63 bpm) at one minute post-incision. Clinically important hypertension or hypotension did not occur in any patient. One patient, receiving beta-blocker therapy, required atropine to control bradycardia. Postoperative respiratory depression did not occur in patients who received less than one micrograms.kg-1.hr-1 with the last increment being given more than 20 minutes before the end of anaesthesia. Slight respiratory depression in the recovery room was reported in one patient, who had received a total of 1.3 micrograms.kg-1.hr-1 of sufentanil, and the last sufentanil increment 24 min before the end of surgery. The most frequently reported side-effects were nausea (35 per cent) and vomiting (23 per cent). Induction, maintenance and recovery from anaesthesia were rated as "good" in 87, 87, and 74 per cent of the cases, respectively, and "satisfactory" in the remainder. We conclude that this technique is valuable to assure good protection of the cardiovascular system without undue respiratory depression during recovery.

Safety of protamine sulfate administration in vasectomized men.

The majority of vasectomized men develop antibodies against different sperm antigens, including protamine. Due to the fact that salmon protamine is used clinically for heparin reversal and that a cross-reactivity has been observed between human and salmon protamine, vasectomized men may be at risk for adverse reactions to protamine sulfate. In order to explore this possibility, serum samples were analyzed for the presence of anti-sperm and anti-protamine antibodies in 20 vasectomized and 20 non-vasectomized men (controls) about to undergo major heart surgery requiring heparin reversal. The patients were closely monitored for any possible reaction following the injection of protamine. Anti-sperm antibodies were detected in the serum of 15 of the vasectomized men whereas only two of the non-vasectomized subjects had this type of antibody. Twenty-five percent of the vasectomized men presented with anti-protamine antibodies; in the control group, none of the patients had developed this type of antibody. Following the administration of protamine sulfate, none of the patients in either group showed any adverse reaction to the drug. It is concluded that vasectomized men are not at increased risk towards adverse reactions following the injection of protamine sulfate.

Microdetermination of selenium in protein fractions isolated by analytical methods.

A method has been developed for the determination of selenium associated with proteins in chromatographic fractions, in polyacrylamide gels, and on nitrocellulose membranes after transfer. This method involves the complete digestion of samples in the purest nitric and perchloric acids and takes advantage of the specificity afforded by the 99% pure 2,3-diaminonaphthalene. The use of these and other reagents of highest purity produces very low blank values and allows a detection limit as low as 0.76 picomoles (60 picograms) of selenium. Quantitative recoveries of selenium in glutathione peroxidase and low coefficients of variation were obtained.