Background

The notion that smoking cannabis may damage the respiratory tract has been introduced in recent years but there is still a paucity of studies on this subject. The aim of this study was to investigate the relationship between cannabis smoking, pneumothorax and bullous lung disease in a population of operated patients.

Methods and findings

We performed a retrospective study on patients operated on for spontaneous pneumothorax. Patients were divided into three groups according to their smoking habit: cannabis smokers, only-tobacco smokers and nonsmokers. Cannabis lifetime exposure was expressed in dose-years (1d/y = 1 gram of cannabis/week for one year). Clinical, radiological and perioperative variables were collected. The variables were analyzed to find associations with smoking habit. The impact of the amount of cannabis consumption was also investigated by ROC curves analysis.

Of 112 patients, 39 smoked cannabis, 23 smoked only tobacco and 50 were nonsmokers. Median cannabis consumption was 28 dose/years, median tobacco consumption was 6 pack/years. Cannabis smokers presented with more severe chronic respiratory symptoms and bullous lung disease and with a higher incidence of tension pneumothorax than both tobacco smokers and nonsmokers. Cannabis smokers also developed a larger pneumothorax, experienced prolonged postoperative stay and demonstrated a higher incidence of pneumothorax recurrence after the operation than nonsmokers did. The risk of occurrence of chronic respiratory symptoms and bullous lung disease in cannabis smokers was dose-related.

Conclusions

Cannabis smoking seems to increase the risk of suffering from respiratory complaints and can have detrimental effects on lung parenchyma, in a dose-dependent manner. Cannabis smoking also negatively affected the outcome of patients operated for spontaneous pneumothorax. A history of cannabis abuse should always be taken in patients with pneumothorax. There may be need for a specific treatment for pneumothorax in cannabis smokers.

中文翻译：

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大麻和吸烟者的继发性自发性气胸和大疱性肺疾病：病例对照研究。

背景

近年来，已经提出了吸烟大麻可能损害呼吸道的观念，但是关于这一主题的研究仍然很少。这项研究的目的是调查手术患者中大麻吸烟，气胸和肺大疱性肺病之间的关系。

方法和发现

我们对接受自发性气胸手术的患者进行了回顾性研究。根据吸烟习惯将患者分为三类：大麻吸烟者，仅吸烟者和不吸烟者。大麻的终生暴露量以剂量-年表示（一年1d / y = 1克大麻/周）。收集临床，放射学和围手术期的变量。分析变量以发现与吸烟习惯的关系。还通过ROC曲线分析调查了大麻消费量的影响。

在112名患者中，有39名吸烟者吸烟，23名仅吸烟者吸烟和50名不吸烟者。大麻中位数消费量为28剂/年，烟草中位数消费量为6包/年。大麻吸烟者比吸烟者和不吸烟者都表现出更严重的慢性呼吸道症状和大疱性肺病，以及紧张性气胸的发生率更高。大麻吸烟者也比不吸烟者发展出更大的气胸，术后住院时间更长，并且术后气胸复发的发生率更高。大麻吸烟者发生慢性呼吸道症状和大疱性肺病的风险与剂量有关。

结论

大麻吸烟似乎会增加患呼吸系统疾病的风险，并且可能以剂量依赖的方式对肺实质产生有害影响。大麻吸烟也对自发性气胸手术患者的结果产生负面影响。气胸患者应始终有大麻滥用史。大麻吸烟者可能需要针对气胸的特殊治疗方法。