Nd-YAG laser damage to metal and silicone endobronchial stents: delineation of margins of safety using an in vitro experimental model.

STUDY OBJECTIVE: To identify margins of safety within which bronchoscopic Nd-YAG laser resection can be performed without damaging indwelling tracheobronchial stents. DESIGN: Experimental in vitro study simulating a patient-care environment. METHODS: Uncovered and covered metal Wallstent (Schneider; Zurich, Switzerland) and Dumon (Bryan Corporation; Woburn, MA) silicone stents were deployed in the tracheobronchial tree of a ventilated and oxygenated (fraction of inspired oxygen, 40%) heart-lung block of a dead canine. Rigid bronchoscopic Nd-YAG (1,064 nm) laser procedures were performed in order to deliver laser energy using fiber-to-target distances of 10 mm and 20 mm, and noncontact, continuous-mode, 1-s pulses at power settings of 10 W, 30 W, and 40 W. The major outcome measure was laser-induced stent damage, defined as discoloration, ignition, or breakage. This was assessed using six power densities: 75 W/cm(2), 172 W/cm(2), 225 W/cm(2), 300 W/cm(2), 518 W/cm(2), and 690 W/cm(2). RESULTS: The uncovered Wallstent and the silicone stent remained intact at power densities of 75 W/cm(2) (10 W, 20 mm) and 172 W/cm(2) (10 W, 10 mm), but were damaged at power densities > 225 W/cm(2) (30 W, 20 mm). The covered Wallstent was damaged at all power densities tested. CONCLUSION: Uncovered Wallstent and silicone stents are not damaged when Nd-YAG laser energy is delivered using power densities < or = 72 W/cm(2) (10 W, 10 mm). Covered Wallstents, however, had a high likelihood of ignition at all power densities studied.

Health risks associated with cigar smoking.

This article summarizes principal findings from a conference convened by the American Cancer Society in June 1998 to examine the health risks of cigar smoking. State-of-the-science reports were presented and 120 attendees (representing government and private agencies, academia, health educators, and tobacco control experts) participated in panels and summary development discussions. The following conclusions were reached by consensus: (1) rates of cigar smoking are rising among both adults and adolescents; (2) smoking cigars instead of cigarettes does not reduce the risk of nicotine addiction; (3) as the number of cigars smoked and the amount of smoke inhaled increases, the risk of death related to cigar smoking approaches that of cigarette smoking; (4) cigar smoke contains higher concentrations of toxic and carcinogenic compounds than cigarettes and is a major source of fine-particle and carbon monoxide indoor air pollution; and (5) cigar smoking is known to cause cancers of the lung and upper aerodigestive tract. JAMA. 2000;284:735-740

Effect of music on state anxiety scores in patients undergoing fiberoptic bronchoscopy.

OBJECTIVE: To study the effect of music on state anxiety levels in patients undergoing flexible fiberoptic bronchoscopy (FFB). DESIGN: Randomized clinical trial using pretests, posttests, and two groups. SETTING: Pulmonary special-procedures unit of a tertiary-care referral center. PATIENTS: Sixty adult patients: 30 patients received music during bronchoscopy and 30 control subjects received no music. RESULTS: The study population had baseline state anxiety levels similar to those previously reported in surgical patients (42.6 +/- 13 vs 42.7 +/- 14; p value, not significant [NS]) and higher than those reported in normal working adults (42.6 +/- 13 vs 34.4 +/- 10; p < 0.001). Experimental and control groups were similar in patient and procedure-related characteristics and baseline pre-FFB state and trait anxiety scores. Although trait anxiety scores decreased significantly after the procedure (pooled post-FFB scores of 32.6 +/- 10 vs pre-FFB scores of 35.5 +/- 11; p < 0.001), no reductions were noted in state anxiety (pooled post-FFB scores of 42.8 +/- 13 vs pre-FFB scores of 42.6 +/- 13; p value, NS). More importantly, playing music through headphones during FFB did not result in a statistically or clinically significant reduction in either state or trait anxiety when compared to control subjects. CONCLUSION: Relaxation music administered through headphones to patients during flexible bronchoscopy does not decrease procedure-related state anxiety.

Comparison of serum carotenoid responses between women consuming vegetable juice and women consuming raw or cooked vegetables.

The objective of this study was to examine serum concentrations of alpha-carotene, beta-carotene, lutein, lycopene, and beta-cryptoxanthin due to consumption of vegetable juice versus raw or cooked vegetables. Subjects included female breast cancer patients who had undergone surgical resection and who were enrolled in a feasibility study for a trial examining the influence of diet on breast cancer recurrence. A high-vegetable, low-fat diet was the focus of the intervention, and some of the subjects were specifically encouraged to consume vegetable juice. At 12 months, blood samples were collected and analyzed for carotenoid concentrations via high-performance liquid chromatography methodology. Matched analysis and paired t test were conducted on two groups: those who consumed vegetable juice (the juice group) and those who consumed raw or cooked vegetables (no juice group). Serum concentrations of alpha-carotene and lutein were significantly higher in the vegetable juice group than in the raw or cooked vegetable group (P < 0.05 and P = 0.05, respectively). Paired t test analysis did not demonstrate a significant difference in serum values of beta-carotene, lycopene, and beta-cryptoxanthin between subjects consuming juice and those not consuming any juice. These results suggest that alpha-carotene and lutein appear to be more bioavailable in the juice form than in raw or cooked vegetables. Therefore, the food form consumed may contribute to the variability in serum carotenoid response to vegetable and fruit interventions in clinical studies.

AIDS-related spontaneous pneumothorax. Risk factors and treatment.

OBJECTIVE: To define risk factors and optimum therapy for AIDS-related spontaneous pneumothorax (PTX). DESIGN: Case-control study. SETTING: Tertiary care center. PATIENTS: Thirty-five patients with AIDS who developed spontaneous PTX between January 1, 1988 and December 31, 1991, of whom 27 (77.1%) did so in the setting of Pneumocystis carinii pneumonia (PCP). Forty-one patients who were diagnosed as having PCP and did not develop PTX served as the control group. RESULTS: Using logistic regression, a history of cigarette smoking, aerosolized pentamidine treatment, and the observation of pneumatoceles by chest radiography were associated with an increased risk of PTX. Although not associated with an increased risk of occurrence of PTX, the use of systemic corticosteroids for PCP treatment was associated with a longer requirement for chest tube drainage. Although chest tube drainage alone was often successful, chemical and surgical pleurodesis was often effective in treating prolonged air leaks and was associated with a lower incidence of recurrent PTX, although this difference did not achieve statistical significance (p = 0.07). CONCLUSIONS: Patients at high risk of developing AIDS-related spontaneous PTX can be identified. Systemic corticosteroids may increase the risk of morbidity from AIDS-related PTX. Chemical and surgical pleurodesis may be of value in short-term treatment and in reducing the risk of recurrence.

Comparison of wedge to forceps videothoracoscopic lung biopsy. Gross and histologic findings.

BACKGROUND: The decreased morbidity and rapid recovery after thoracoscopic lung biopsy compared with open lung biopsy by thoracotomy is increasingly recognized, as is the ability to obtain satisfactory diagnostic material thoracoscopically. To our knowledge, however, there has been no systematic comparison of specimen quality using different thoracoscopic biopsy techniques. The purpose of this study was to compare histologic features of lung parenchyma obtained by videothoracoscopic forceps and wedge biopsy techniques. METHODS: Five adult swine were anesthetized, intubated, and ventilated. Sequential left and right videothoracoscopies were performed to obtain biopsy specimens of lung parenchyma using 5-mm endoscopic cupped forceps. Specimens were obtained from fully inflated lung and from partially atelectatic (deflated) lung. Electrosurgery was applied during forceps biopsy for airleak closure. Limited wedge biopsy specimens were obtained using an endoscopic stapler. One hundred thirteen forceps biopsy specimens (55 inflated, 58 deflated) and 24 sections from 8 wedge biopsy specimens were examined. Specimens were assessed for overall histologic quality and ease of microscopic interpretation. Specific histologic features were then evaluated including presence of artifact, congestion and hemorrhage, degree of alveolar inflation, and number of bronchioles and vessels per cross-sectional area. Whole lungs from two animals were examined for extent and depth of lung injury at the areas of biopsy. RESULTS: No major differences in overall microscopic specimen quality were detected among the different techniques nor were significant differences noted between lung inflated and lung deflated forceps biopsy technique. Wedge sections contained more vessels per unit area (p < 0.001), perhaps reflecting the more peripheral nature of forceps biopsy. Small amounts of thermal or crush artifact were noted on the surface of forceps biopsy specimens, but did not affect overall specimen quality. CONCLUSIONS: Multiple 5-mm forceps biopsy specimens were of comparable quality to single wedge biopsy specimens obtained by endoscopic stapling. Although greater numbers of vessels were present in endoscopic stapled wedge biopsy specimens, multiple forceps biopsy specimens in fact, contain amply sufficient vessels for histologic analysis.

The Gulf war: anaesthetic experience at 32 Field Hospital Department of Anaesthesia and Resuscitation.

The organisation and the workload of the anaesthetic department of a Field Hospital deployed during the Gulf war were described. Suggestions are made as to how the problems encountered might be overcome in the future.