Concept of BIDI years: Relevance to the perioperative period.

Background: The cumulative effect of cigarette smoking is usually measured by "pack years," but the same is not present for Bidis. This study was conducted to calculate the concept of "bidi years" in comparison to the concept of "pack-years" for a cigarette.

Methods: Thirty random samples, each of bidis and cigarettes, were selected through a survey of common brands used by smokers in India. The nicotine and carbon monoxide (CO) contents were analyzed by high-pressure liquid chromatography and gas chromatography methods, respectively.

Results: The average nicotine content in thirty samples of different Bidis and Cigarettes was 214.46 ± 57.8 and 616.31 ± 22.6 mg/dL, respectively (P < 0.001). The CO content with a lower mean of 15.57 ± 5.88 was observed in cigarettes as compared to 70.4 ± 22.08 in bidies (P < 0.001). The weight of one cigarette is 0.56 times that of the weight of one bidi. Based on the nicotine content, the equivalent pack years for bidis is calculated as 43 bidis per day per year.

Conclusion: Based on the nicotine content, it is proposed that the equivalent for one cigarette pack-year or 20 cigarette years are taken as 43 bidis per day per year. Even though each bidi stick has an average of 0.46 times the nicotine content of cigarettes, longer abstinence as compared to cigarette is required to bring the nicotine level to normal due to the deeper puffs needed. With the CO content of bidis being 4.5 times that of cigarettes, it is advised that the minimum duration of cessation of smoking before operative procedures be 24 h as compared to 6 h for cigarettes.