[Pneumothorax following recreational inhalation of nitrous oxide]

CASE REPORT

A 21 year old man was admitted to hospital as an emergency complaining of left sided chest pain. Chest radiograph revealed a complete non compressive left-sided pneumothorax which resolved following thoracic drainage. A more detailed history revealed repeated and regular use of nitrous oxide by inhalation, for its consciousness-altering effect during rave parties.

DISCUSSION

The principal side effects occurring as a consequence of repeated exposures to nitrous oxide are haematological, neuropsychiatric and teratogenic. Rare cases of pneumothorax have been described associated with the use of nitrous oxide occurring as complications of anaesthesia or during laparoscopy where gas diffuses from the abdominal to the pleural cavity. Illicit use of nitrous oxide is rare and usually occurs in medical workers. Its spreading to the public may lead to accidents and unanticipated side effects.

CONCLUSION

Inhaled nitrous oxide can reveal asymptomatic pneumothorax by worsening it. The consequences can be dramatic in case of illicit use because of ignorance of side effects.

[Evaluation of combined chemotherapy with vinorelbine, ifosfamide and cisplatin in the treatment of metastatic non-small cell bronchial carcinoma]

INTRODUCTION

In France, cancer of the bronchus is responsible for 25,000 deaths per year. Non small cell lung cancer (NSCLC) represents 80% of bronchial carcinoma of which 40-50% are mefastatic at the time of diagnosis. At present, although the therapeutic benefits are modest, it is now recognised that combination chemotherapy including platinum salts improves the survival of these patients.

METHODS

We analysed retrospectively a cohort of 57 patients suffering from stage IV NSCLC treated with chemotherapy combining cisplatin (80 mg/rn2 on day 1), vinorelbine (25 mg/rn2 on days 1 and 8) and ifosfamide (3000 mg/in 2 on day 1), (NIP), repeated every 21 days.

RESULTS

The population studied comprised 6 women and 51 men, of average age 59.8 +/- 9.1 years. A history tobacco use (smokers and ex-smokers) was identified in 93%. The WHO performance index was equal to or greater than 2 in 22.8%. All patients were studied in terms of toxicity and overall survival but only 40 (70%) were able to be evaluated in terms of response to treatment (on account of having received more than three cycles of NIP chemotherapy). For the group considered as a whole, the median survival was 6.7 months with a one year survival of 24.5%. Median survival without progression was 4.4 months. The most frequent toxicities were haematological and digestive. They were most common among patients over the age of 70 but had no effect on median survival. For the 40 patients for whom chemotherapy was evaluable, the objective response rate was 20%. This objective response was the only factor that was signiticantly correlated with one year survival: 62.5% in responders, 28.1% in non-responders (p < 0.05).

CONCLUSION

Treatment of stage IV NSCLC with NIP chemotherapy is effective and improves the survival of these patients independently of other prognostic factors such as age, the presence of cerebral metastases, performance status, histological type, the number of metastatic sites or the serum LOH level.

[Pulmonary embolism and sibilant types of chronic obstructive pulmonary disease decompensations]

Pulmonary Embolism (PE) poses an important diagnostic problem in patients with chronic obstructive pulmonary disease (COPD). Indeed PE may aggravate the already precarious respiratory state of these fragile patients. Moreover, these two conditions share common symptoms: dyspnoea, wheezing, pleural pain, haemoptysis, palpitations and signs of right cardiac insufficiency. In two studies, one retrospective and the other prospective, we investigated the incidence of PE in patients with non-infective exacerbations of their COPD. The retrospective study was carried out over two years and involved 50 COPD patients with non-infective respiratory exacerbations. In this population, 10 patients out of 50 (20%) had a documented PE. No predictive factor was identified. The prospective study was conducted over one year and COPD patients admitted to hospital with exacerbations were included in the study if they had a positive D-dimer blood test and no evidence of acute respiratory infection. 31 patients were studied with Doppler ultra-sound examination of the legs and a lung perfusion scan. The presence or absence of PE was determined and the two groups were compared. 9 patients out of 31 (29%) had a documented PE. Six of these nine patients had a deep venous thrombosis (DVT). Two predictive factors of PE were identified: existence of a DVT and a significant fall in PaO(2) from baseline state (DeltaPaO(2) > 22 mmHg). We conclude that PE is a frequent (20 to 30%) of non-infective respiratory decompensation in COPD patients. Faced with an unexplained respiratory exacerbation in these patients, a lung perfusion scan should be routinely undertaken to rule out a PE when the D-dimers are positive.

[Traumatic pulmonary pseudocysts. Mechanisms of formation]

Pulmonary pseudocysts (PPC) classically relate to chest trauma. It is a rare entity in adults, with multiple differential diagnosis. PPC most often evolve favorably. The clinical diagnosis is difficult to assess due to the poor and non specific clinical data. Chest radiographs are usually unsufficient for the diagnosis and the imaging modality of choice is computed tomography (CT). CT patterns of PPC relate to single or numerous cavities surrounded by air space consolidations. The physiopathological mechanisms of PPC remains uncertain. The histological study of this reported case affords some worth data to highlight the pathogenesis of this acquired abnormality.