Background-In patients with chronic heart failure (CHF), central sleep apnea (CSA) and enhanced ventilatory response (V E/V CO 2 slope) to exercise are common. Both breathing disorders alone indicate poor prognosis in CHF. Although augmented chemosensitivity to CO 2 is thought to be one important underlying mechanism for both breathing disorders, it is unclear whether both breathing disorders are related closely in patients with CHF. Methods and Results-We investigated 20 CHF patients with clinically important CSA (apnea-hypopnea-index (AHI), number of episodes per hour Ն15) and 10 CHF patients without CSA. Pϭ0.886). In contrast, the positive correlation of the V E/V CO 2 slope, determined by cardiopulmonary exercise testing, with the AHI was highly significant (PϽ0.001). The V E/V CO 2 slope was significantly increased in patients with CSA compared with those without CSA (29.7 versus 24.9; PϽ0.001). Conclusions-The ventilatory response to exercise is significantly augmented in CHF patients with CSA compared with those without. In contrast to peak V O 2 and LVEF, the V E/V CO 2 slope is strongly related to the severity of CSA in patients with CHF, which underscores an augmented chemosensitivity to CO 2 as a common underlying pathophysiological mechanism.

Background: One of the consistently observed features in chronic obstructive pulmonary disease (COPD) are markedly increased neutrophils in the airways which are accompanied by increased levels of interleukin-8 (IL-8) in induced sputum and bronchoalveolar lavage fluid. To some extent, IL-8 may derive from bronchial epithelial cells since airway epithelium plays a crucial role in initiating and augmenting host defense mechanisms. Objectives: We hypothesized that a marked increase in bronchoepithelial IL-8 expression and release may be found in the airway epithelium of COPD patients compared to ‘healthy’ smokers and never-smokers. Methods: Primary bronchoepithelial cell cultures from COPD patients, smokers, and never-smokers were established. The unstimulated and TNFα-induced IL-8 release was measured by enzyme-linked immunosorbent assay. In addition, mRNA expression levels were quantified by means of reverse transcriptase polymerase chain reaction and light cycler measurements. Results: In subjects with COPD the constitutive and stimulated IL-8 release was significantly higher compared to ‘healthy’ smokers and control subjects, whereas no differences were seen between smokers and the control group. Quantitative assessment of transcript levels confirmed these data, displaying significantly higher mRNA levels in primary bronchial epithelial cells from COPD patients compared to controls (p < 0.05) in uninduced and stimulated conditions (p < 0.05). Conclusions: These results suggest that patients with chronic obstructive airflow limitation are characterized by a significant upregulation of bronchial epithelial IL-8 expression levels and secretion, indicating specific differences in epithelial cell activation in COPD patients compared to smokers and control subjects.

Genotoxicity related to waste anaesthetic gas exposure is controversial. We have investigated the frequency of sister chromatid exchanges in peripheral lymphocytes of operating room personnel exposed to trace concentrations of isoflurane and nitrous oxide. Occupational exposure was recorded using a direct reading instrument. Frequencies of sister chromatid exchanges were measured in lymphocyte cultures of 27 non-smokers working in the operating room and 27 non-smoking controls. Personnel were exposed to an 8-h time-weighted average of nitrous oxide 11.8 ppm and isoflurane 0.5 ppm. After exposure, sister chromatid exchange frequency was increased significantly (mean 9.0 (SD 1.3) vs 8.0 (1.4) in exposed and control personnel, respectively) (P < 0.05). We conclude that exposure to even trace concentrations of waste anaesthetic gases may cause genetic damage comparable with smoking 11-20 cigarettes per day.

SummaryWe report the findings of a study on exposure of operating room staff to sevoflurane, halothane and nitrous oxide during induction and maintenance of anaesthesia in children. Concentrations of anaesthetic agents in the operating theatre were measured directly by highly sensitive, photoacoustic infrared spectrometer during 20 anaesthetics. Samples were taken from the breathing zones of the anaesthetist and the circulating nurse. The operating theatre was of modern design with an air conditioning system providing 20 changes of air each hour. The threshold values of 100 ppm N 2 O, 50 ppm isoflurane and 10 ppm halothane recommended by the United Kingdom Committee for Occupational Safety and Health (COSH) were exceeded in several cases for a short time during mask induction. After tracheal intubation, trace concentrations of sevoflurane, halothane and N 2 O were mostly under the recommended levels and comparable to levels measured during adult anaesthesia.