The number of deaths from carbon monoxide (CO) poisoning remained constant for many years but has recently started to fall. There are three reasons. Firstly, it has become more fashionable to commit suicide by more sophisticated methods, particularly now that tranquillisers and antidepressants are widely prescribed. Secondly, Britain's domestic gas supply is being changed over from coal gas to natural gas, which contains no carbon monoxide-though so far only an eighth of the country has actually been converted to the new gas. Thirdly, and perhaps most significant, is the changeover which has taken place in the manufacture of gas for domestic use, coal carbonization having given way to oil reforming. Techniques for reducing the amount of CO present have also been introduced, but as G. Thurston' has shown, inadequate combustion or ventilation can be lethal even when the original fuel contains no CO. So in about eight years, when the whole country has been converted to natural gas, there will still be numbers of patients with CO poisoning needing resuscitation.Recently J. S. Smith and S. Brandon2 reviewed 206 episodes of CO poisoning in Newcastle. The mortality rate was 3900. In 20% of patients recovery was complicated by prolonged delirium suggesting that "all degrees of functional or structural neurological damage may have occurred, yet oxygen therapy was given in only 43.8% of suicidal and 32-5% of accidental exposures." They suggest that in view of the risk of persistent neuropsychiatric sequelae current patterns of management should be revised.In selecting a form of therapy there are two aspects to consider: firstly, the prevention of death and, secondly, the reduction of neuropsychiatric sequelae such as those described by H. Garland and J. Pearce.3 Carboxyhaemoglobin should be eliminated as quickly as possible because its presence alters the dissociation curve of the remaining oxyhaemoglobin, impeding oxygen release to the tissues.4 J. S. Haldane5 was the first to describe the use of hyperbaric oxygen in CO poisoning, when he failed to poison a mouse placed in a jar containing two atmospheres of oxygen and one of CO. This was all the more remarkable for the fact that the affinity of haemoglobin for CO is about 250 times that for oxygen. Hyperbaric oxygen keeps the patient's tissues oxygenated by the oxygen physically dissolved in the plasma at a time when his haemoglobin is not available to him for oxygen transport. It is also the most efficient means of reducing the carboxyhaemoglobin level, as was shown by T. A. Douglas and his colleagues6 in 1962 when they compared the efficiencies of oxygen at one atmosphere's pressure, oxygen at two atmospheres' pressure, and of 50/% and 70 % carbon dioxide in oxygen.

Pirfenidone is one of two approved therapies for the treatment of idiopathic pulmonary fibrosis (IPF). Randomised controlled clinical trials and subsequent post hoc analyses have demonstrated that pirfenidone reduces lung function decline, decreases mortality and improves progression-free survival. Long-term extension trials, registries and real-world studies have also shown similar treatment effects with pirfenidone. However, for patients with IPF to obtain the maximum benefits of pirfenidone treatment, the potential adverse events (AEs) associated with pirfenidone need to be managed. This review highlights the well-known and established safety profile of pirfenidone based on randomised controlled clinical trials and real-world data. Key strategies for preventing and managing the most common pirfenidone-related AEs are described, with the goal of maximising adherence to pirfenidone with minimal AEs.

Preoperative pulmonary function testing helps clinicians to make decisions on management of lung resection candidates. Although many studies of patients before abdominal surgery have focused on the utility of preoperative pulmonary function testing, methodologic difficulties undermine the validity of their conclusions. The impact of testing on care of other preoperative patients is even less clear because of poor study design and insufficient data. Therefore, further investigation is necessary before a consensus can be reached on the role of preoperative pulmonary function testing in evaluating patients before all surgical procedures except lung resection.

The number of deaths from carbon monoxide (CO) poisoning remained constant for many years but has recently started to fall. There are three reasons. Firstly, it has become more fashionable to commit suicide by more sophisticated methods, particularly now that tranquillisers and antidepressants are widely prescribed. Secondly, Britain's domestic gas supply is being changed over from coal gas to natural gas, which contains no carbon monoxide-though so far only an eighth of the country has actually been converted to the new gas. Thirdly, and perhaps most significant, is the changeover which has taken place in the manufacture of gas for domestic use, coal carbonization having given way to oil reforming. Techniques for reducing the amount of CO present have also been introduced, but as G. Thurston' has shown, inadequate combustion or ventilation can be lethal even when the original fuel contains no CO. So in about eight years, when the whole country has been converted to natural gas, there will still be numbers of patients with CO poisoning needing resuscitation.Recently J. S. Smith and S. Brandon2 reviewed 206 episodes of CO poisoning in Newcastle. The mortality rate was 3900. In 20% of patients recovery was complicated by prolonged delirium suggesting that "all degrees of functional or structural neurological damage may have occurred, yet oxygen therapy was given in only 43.8% of suicidal and 32-5% of accidental exposures." They suggest that in view of the risk of persistent neuropsychiatric sequelae current patterns of management should be revised.In selecting a form of therapy there are two aspects to consider: firstly, the prevention of death and, secondly, the reduction of neuropsychiatric sequelae such as those described by H. Garland and J. Pearce.3 Carboxyhaemoglobin should be eliminated as quickly as possible because its presence alters the dissociation curve of the remaining oxyhaemoglobin, impeding oxygen release to the tissues.4 J. S. Haldane5 was the first to describe the use of hyperbaric oxygen in CO poisoning, when he failed to poison a mouse placed in a jar containing two atmospheres of oxygen and one of CO. This was all the more remarkable for the fact that the affinity of haemoglobin for CO is about 250 times that for oxygen. Hyperbaric oxygen keeps the patient's tissues oxygenated by the oxygen physically dissolved in the plasma at a time when his haemoglobin is not available to him for oxygen transport. It is also the most efficient means of reducing the carboxyhaemoglobin level, as was shown by T. A. Douglas and his colleagues6 in 1962 when they compared the efficiencies of oxygen at one atmosphere's pressure, oxygen at two atmospheres' pressure, and of 50/% and 70 % carbon dioxide in oxygen.

Information related to the clinical characteristics and isolated microbes associated with lung abscesses comparing immunocompromised (IC) to non-immunocompromised (non-IC) patients is limited. A retrospective review for 1984-1996 identified 34 consecutive adult cases of lung abscess (representing 0.2% of all cases of pneumonia), including 10 non-IC and 24 IC patients. Comparison of age, gender, tobacco use, pre-existing pulmonary disease or recognized aspiration risk factors were not significantly different between the two groups. Upper lobe involvement accounted for the majority of cases, although multi-lobe involvement was limited to IC patients. There were no differences in the need for surgical intervention, and mortality was very low for both groups. Anaerobes were the most frequent isolates for non-IC patients (30%), whereas aerobes were the most frequent isolate for IC patients (63%). Importantly, certain organisms were exclusively isolated in the IC group and multiple isolates were obtained only from the IC patients.Thus, comparing non-IC to IC patients, clinical characteristics may be similar whereas important differences may exist in the microbiology associated with lung abscess. These findings have important implications for the clinical management of these patient groups, and support a strategy to aggressively identify microbial agents in abscess material.

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We tested the hypothesis that intermittent ventilatory assistance in patients with severe chronic obstructive pulmonary disease (COPD) improves pulmonary function and exercise capacity. Twenty stable patients with severe COPD were recruited from outpatient pulmonary clinics and were randomized to use a poncho wrap, negative-pressure ventilator or to receive standard care. After 6 months, the patients receiving standard care were switched over to the ventilator and vice versa, and follow-up was continued for an additional 6 months. After 3 to 6 months of ventilator use, we observed no clinically significant improvements in FEV1, FVC, blood gas determinations, maximal inspiratory and expiratory pressures, and exercise duration. However, 11 of our patients dropped out of the study because of an inability to tolerate the ventilator, and all but one of the nine who completed the study expressed dissatisfaction with it, using it for less time (4.1 h/day) than we recommended. Musculoskeletal pain and inconvenience were the most frequently voiced complaints. Because we did not document that ventilator use actually rested the respiratory muscles in our patients and because duration of ventilator use may have been too brief, we cannot conclude that intermittent rest of respiratory muscles in patients with severe COPD fails to bring about improvement. On the other hand, our results demonstrate that the poncho wrap ventilator is poorly tolerated by patients with severe COPD in a typical outpatient setting. We suggest that future trials seek to utilize better tolerated ventilatory assist devices.

No abstract