Carboxyhaemoglobin levels in water-pipe and cigarette smokers

Carbon Monoxide as a Potential Therapeutic Agent: A Molecular Analysis of Its Safety Profiles

Carbon monoxide (CO) is endogenously produced in mammals, with blood concentrations in the high micromolar range in the hemoglobin-bound form. Further, CO has shown therapeutic effects in various animal models. Despite its reputation as a poisonous gas at high concentrations, we show that CO should have a wide enough safety margin for therapeutic applications. The analysis considers a large number of factors including levels of endogenous CO, its safety margin in comparison to commonly encountered biomolecules or drugs, anticipated enhanced safety profiles when delivered via a noninhalation mode, and the large amount of safety data from human clinical trials. It should be emphasized that having a wide enough safety margin for therapeutic use does not mean that it is benign or safe to the general public, even at low doses. We defer the latter to public health experts. Importantly, this Perspective is written for drug discovery professionals and not the general public.

Cardiovascular Effects of Hookah Smoking: Potential Implications for Cardiovascular Risk

Introduction

Smoking is a major cause of cardiovascular morbidity and mortality worldwide. Hookah (ie, waterpipe) smoking is a centuries-old revived yet understudied global epidemic of tobacco use. Because of the traditional set-up of a hookah-pipe, in addition to inhaling tobacco-combustion products, smokers are also exposed to large amounts of charcoal combustion products from the burning charcoal briquettes used to heat the hookah flavored tobacco. Despite being heavily advertised and actively glamorized in the mass media as a healthier tobacco alternative, the toxicological constituents of hookah smoke—including nicotine, carbon monoxide, particulates, oxidants, heavy metals, phenols and flavorants—indicate the potential to cause adverse cardiovascular events.

Methods

Herein, we review evidence on hookah smoke toxicological constituents, cardiovascular effects and potential mechanisms by which hookah smoke aerosol could cause cardiovascular disease.

Results

The evidence reviewed here indicates that contrary to the widespread popular belief that hookah is a healthier tobacco alternative, the constituents of hookah smoke aerosol contains similar chemicals compared to cigarette smoke, many of which are known to be harmful to cardiovascular health and mediated by similar pathophysiologic processes. Because the burning charcoal briquettes are a unique source of toxicant emissions specific to hookah smoking, some constituents differ in their quantities from cigarettes with some of their cardiovascular effects unknown.

Conclusions

To date, much more is known about the constituents and their toxicology than about the effects of hookah smoking on human cardiovascular health. Further research on long-term consequences of hookah use is needed.

Implications

This review provides an overview on the potential impact of hookah smoking on cardiovascular health. Readers will gain an insight into evidence on its toxicological constituents, human health effects, and pathophysiological mechanisms by which hookah smoking might cause cardiovascular disease. The review also highlights current research gaps regarding the cardiovascular consequences of hookah smoking, specifically the long-term consequences in the United States and Europe among flavored-hookah tobacco users.

Evaluating ECG and carboxyhemoglobin changes due to smoking narghile

PURPOSE

This study aimed to investigate whether increased carboxyhemoglobin (COHB) levels and ECG changes, which associated with fatal ventricular dysrhythmias, including increased QT, P-wave and T peak (Tp)-Tend (Te) dispersion, can be detected after smoking narghile, which is a traditional method of smoking tobacco that is smoked from hookah device.

MATERIALS AND METHODS

After local ethics committee approval, this prospective study was conducted using healthy volunteer subjects at a "narghile café," which is used by people smoking narghile in an open area. Before beginning to smoke narghile, all subjects' 12-lead electrocardiographs (ECG), measurements of COHB levels, and vital signs were recorded. After smoking narghile for 30 min, the recording of the 12-lead ECGs and the measurements of COHB level and all vital signs were repeated.

RESULTS

The mean age of subjects was 26.8 ± 6.2 years (min-max: 18-40), and 28 subjects (84.8%) were male. Before smoking narghile, the median value of subjects' COHB levels was 1.3% (min-max: 0-6), whereas after smoking, the median value of COHB was 23.7% (min-max: 6-44), a statistically significant increase (p < 0.001). Analysis of the subjects' ECG changes after smoking narghile showed that dispersions of QT, QTc, P-wave and Tp-Te were increased, and all changes were statistically significant (p < 0.001 for all parameters).

CONCLUSION

Although, especially among young people, it is commonly thought that smoking narghile has less harmful or toxic effects than other tobacco products. The results of this study and past studies clearly demonstrated that smoking narghile can cause several ECG changes - including increased QT, P-wave and Tp-Te dispersion - which can be associated with ventricular dysrhythmias.

Health effects associated with waterpipe smoking

OBJECTIVE

It is widely held that waterpipe smoking (WPS) is not associated with health hazards. However, several studies have documented the uptake of several toxicants and carcinogens during WPS that is strongly associated with harmful health effects. This paper reviews the literature on the health effects of WPS.

DATA SOURCES

Three databases-PubMed, MEDLINE and EMBASE-were searched until August 2014 for the acute and long-term health effects of WPS using the terms 'waterpipe' and its synonyms (hookah, shisha, goza, narghileh, arghileh and hubble-bubble) in various spellings.

STUDY SELECTION

We included original clinical studies, case reports and systematic reviews and focused on clinical human studies. ∼10% of the identified studies met the selection criteria.

DATA EXTRACTION

Data were abstracted by all three authors and summarised into tables. Abstracted data included study type, results and methodological limitations and were analysed jointly by all three authors.

DATA SYNTHESIS

WPS acutely leads to increased heart rate, blood pressure, impaired pulmonary function and carbon monoxide intoxication. Chronic bronchitis, emphysema and coronary artery disease are serious complications of long-term use. Lung, gastric and oesophageal cancer are associated with WPS as well as periodontal disease, obstetrical complications, osteoporosis and mental health problems.

CONCLUSIONS

Contrary to the widely held misconception, WPS is associated with a variety of adverse short-term and long-term health effects that should reinforce the need for stronger regulation. In addition, this review highlights the limitations of the published work, which is mostly cross-sectional or retrospective. Prospective studies should be undertaken to assess the full spectrum of health effects of WPS, particularly in view of its growing popularity and attractiveness to youth.

Multiple patients with carbon monoxide toxicity from water-pipe smoking

This case report describes carbon monoxide toxicity from prolonged shisha (water-pipe) smoking. The evidence base for the source and pathway of toxicity is discussed. This practice has been increasing in the UK in recent years, and emergency physicians need to be aware of the high levels of CO, with the consequent risk of clinical poisoning from water-pipe smoking.

Anesthesia implications of waterpipe use

The waterpipe is an ancient Middle Eastern tobacco delivery system, which is also known as hookah, shisha, or narghile, and it is gaining widespread use. Waterpipes are often perceived as less dangerous than cigarettes. The amount of smoke inhaled in a waterpipe session may equal that produced by more than 100 cigarettes with high nicotine, carbon monoxide, and carcinogen intake. A case of significantly elevated intraoperative carboxyhemoglobin level and decreased oxyhemoglobin saturation in a patient with recent waterpipe use is presented.