Dying for a cigarette

Midwives magazine: Issue 7 :: 2011

Carbon monoxide kills, but awareness about exposure and its effects is poor. Carmel O’Gorman, Heart of England NHS Foundation Trust’s smoking and pregnancy coordinator, explores routine testing and best practice.

NICE recommends that a carbon monoxide (CO) screening service is included within the antenatal care package for all pregnant women (NICE, 2010). This is advocated because annually more than 91,000 babies born in England are exposed to tobacco smoke in utero (Department of Health (DH), 2011a), most of whom are born to young and disadvantaged women (Bolling et al, 2007). Additionally, one in four pregnant women who do not smoke may be exposed to second-hand smoke at home (Bolling et al, 2007). Universal CO screening can highlight exposure to this smoke and help prevent accidental CO poisoning from other sources, such as gas, coal, wood or paraffin cooking and heating appliances. Branded the ‘silent killer’, CO is a poisonous gas that is colourless and odourless. It can cause death and serious injury (DH, 2010). Many UK maternity services have implemented universal CO screening with various challenges and successes. This article explores the key issues and suggests good practice. 

Smoking and pregnancy
Smoking in pregnancy hit the headlines in 2010 after NICE recommended that all women are offered CO testing as a routine part of their first antenatal booking appointment and then appropriately throughout pregnancy (NICE, 2010). Concerns were raised by the RCM that this may make women feel guilty (O’Malley, 2010) and it is akin to policing smoking behaviour at a high personal cost for some (Wickham, 2010). Others feared that this may undermine the relationship of trust among women and midwives (Clift-Matthews, 2010). The ensuing debate included harsh comments, for example: ‘What is wrong with making a woman feel guilty about deliberately inhaling several hundred toxic compounds into her system and inflicting it on that of her baby’s? They should be made to feel guilty, idiotic, ashamed and worthless. That way, they might not do it anymore’ (www.guardian.co.uk, 2011). Although a CO test can assess whether or not someone smokes, it may be a helpful motivator for smoking cessation, not merely a lie detector. A non-judgemental, supportive approach is essential. Blaming vulnerable women who smoke is counterproductive. 

A new approach is needed. In the UK, smoking is the cause of up to 5000 miscarriages, 300 perinatal deaths, 2200 premature births and around 19,000 babies with low birthweight annually (Royal College of Physicians, 2010), costing the NHS between £23.5m and £64m (Godfrey et al, 2010). This underpins the government’s aim to reduce smoking in pregnancy to 11% or less by 2015 (DH, 2011b). Yet pregnant women who smoke feel ashamed and are reluctant to tell their midwife or ask for help for fear of being judged or criticised (DH, 2007), making it difficult for midwives to offer support. 

With this in mind, universal CO screening creates an opportunity to provide all women with immediate and tangible evidence of the presence of smoke components. Personalised CO feedback educates women about the smoking-related risk to their own health and that of their baby’s, enhancing their motivation to stop. Initial CO results may sound alarming, but within 48 hours of stopping smoking, CO levels fall to non-smoking levels.

Antenatal CO testing was highlighted in the recent BBC3 TV programme Misbehaving mums-to-be. The baby’s CO reading was displayed on a computer screen and a hard-hitting approach using fetal health as a motivator for quitting was used to promote cessation. Some women found CO feedback in this manner emotionally distressing; not all women successfully stopped. Though reportedly successful in Rotherham (Jones, 2011), time will tell whether this high-impact method is effective across the UK.  

In addition to 4000 chemicals, cigarette smoke contains substantial amounts of CO; each cigarette delivers 10 to 20 times more CO than nicotine. The affinity of the gas for haemoglobin (Hb) is 200 times greater than oxygen and its half-life is about four to five hours. This means smokers are exposed to high blood CO levels daily and can have up to 20% less oxygen in their systems than non-smokers. The gas rapidly crosses the placenta and binds to fetal Hb with a greater affinity than maternal Hb. It also takes much longer for the gas to clear the baby’s system than the mother’s too. The effects of CO on the fetus cannot be ignored either – it causes chronic hypoxia, and is detrimental to growth and development (Dempsey and Benowitz, 2001). It should be noted that passive smoking is likely to have adverse effects similar to active maternal smoking, but of smaller magnitude (Royal College of Physicians, 2010).

The role of the midwife
Midwives make a unique contribution to public health (Midwifery 2020, 2010). Yet evidence shows that some midwives doubt the relevance of offering CO screening for non-smokers. Time constraints are a barrier. Domestic violence, alcohol and mental health issues are seen as a greater priority (Bauld et al, 2007). Yet 21% of pregnant women (non-smokers) live with another smoker (Bolling et al, 2007) and are potentially exposed to second-hand smoke. 

Accidental CO poisoning
Despite the alarming statistics, awareness is low. Annually in England and Wales, CO poisoning causes about 50 deaths and 200 non-fatal injuries. Pregnant women are at increased risk of CO poisoning  (DH, 2010) and recent cases have been reported (Jones, 2011; Carroll, 2010). In the home, the main sources of CO are incorrectly installed, poorly maintained and ventilated cooking and heating appliances, such as those using gas, coal, wood or paraffin. The most significant exposure to CO comes from cigarette smoking or car exhaust fumes (Health Protection Agency, 2009). 

CO results
Women who smoke, recent ex-smokers and women with a CO reading of 7ppm or above should be referred for support (NICE, 2010). Some practice challenges for midwives are highlighted by Usmani et al (2008) who compared data on self-reported smoking behaviour with CO levels among pregnant women. This paper includes comments from women who were probably smoking, explaining their CO readings:
✻ ‘Sitting in front of a smoker on the bus here’ (CO 24ppm)
✻ ‘Gas fire needs fixing’ (CO 13ppm)
✻ ‘Walked under a bridge on the way here – a lot of pollution’
(CO 9ppm).

Yet some women who neither smoke, nor are exposed to second-hand smoke, may have a high CO result due to unknowingly being exposed. Women with a CO reading above 10ppm should contact the free Health and Safety Executive gas safety advice line (NICE, 2010).

Implications for practice
Training is recommended to equip all midwives with the knowledge and skills to use CO monitors, including infection control guidance. Midwives have a duty of care to provide women with full and honest information about the purpose of CO screening, the implications and possible actions based on the result. Good quality written information should be available early. CO testing is not compulsory, and women should not be coerced. 

There is a range of CO monitors available at varying costs. Some measure the baby’s CO reading. Yet lifestyle messages should focus on women’s health as motivation for stopping, rather than being ‘baby-centric’. Ideally, key public health messages should occur by ten weeks’ gestation (Midwifery 2020, 2010), since the benefits of early cessation are greater (Polakowski et al, 2009). Midwives can tie the CO feedback into a discussion about how stopping smoking quickly improves oxygen levels.

By integrating CO screening into antenatal care, midwives can highlight the risks of second-hand smoke exposure, and play a role in encouraging partners and others to stop smoking – this in turn will promote smoke-free homes and cars. Midwives can further help to reduce deaths and near misses from CO poisoning. Safety awareness messages could include: installing a CO alarm rather than the ‘black spot’ CO detectors, getting household appliances checked annually by a registered installer and tenants asking to see their landlord’s gas safety record (Gas Safety Trust, 2010). 

Conclusion
Universal CO screening aims to ensure that all smokers are identified and offered help to stop (NICE, 2010). Additionally, the risks of exposure to second-hand smoke and CO poisoning can be highlighted. Routinely offering this service will be challenging in this present climate of NHS cut-backs and midwife shortages, but, nevertheless, the problem is here to stay and how this screening is delivered will need to be included in service provision planning. Midwives should take ownership of this initiative, share learning and support national CO-awareness week, which starts on 21 November. 

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Key messages for midwives
–Offer all women CO screening as early in pregnancy as possible
–Facilitate women’s informed choice and consent or refusal for CO screening
–Review smoking status and offer CO testing throughout pregnancy, for example at day assessment units and antenatal wards
–Promote awareness of exposure to second-hand smoke and accidental CO poisoning
–CO monitors have a place in every midwife’s public health tool-kit

RCM Communities
Should midwives offer routine CO screening to all pregnant women? Join in at: http://communities.rcm.org.uk


For useful leaflets, please visit: www.co-awareness.org or: www.bloominghealth.co.uk


References

Bauld L, Wilson M, Kearns A, Reid M. (2007) Exploring reductions in smoking during pregnancy in Glasgow. See: http://www.gcph.co.uk/assets/0000/0428/Smoking_During_Pregnancy_FinalReport_Oct07.pdf (accessed 27 September 2011).

Bolling K, Grant C, Hamlyn B, Thornton A. (2007) Infant Feeding Survey 2005. A survey conducted on behalf of The Information Centre for health and social care and the UK health departments by BMRB Social Research. The Information Centre: London. See: http://www.ic.nhs.uk/webfiles/publications/ifs06/2005%20Infant%20Feeding%20Survey%20(final%20version).pdf (accessed 14 November 2011).

Carroll A. (2010) Lowestoft: Pregnant woman in £2500 payout after carbon monoxide poisoning. See: http://www.eadt.co.uk/news/lowestoft_pregnant_woman_in_2_500_payout_after_carbon_monoxide_poisoning_1_735543 (accessed 14 November 2011).

Cliff-Mathews V. (2010) Providing long-term support to women. British Journal Midwifery 18(7): 412.

Dempsey DA, Benowitz NL. (2001) Risks and benefits of nicotine to aid smoking cessation in pregnancy. Drug Safety 24(4): 277-322.

Department of Health. (2007) Smoking and pregnancy qualitative research report. Research Works: Hertfordshire.

Department of Health. (2010) Carbon monoxide poisoning: needless deaths, unnecessary injury. Letter from the Interim Chief Medical Officer and Chief Nursing Officer, PL/CMO/2010/02, PL/CNO/2010/02, Department Health Gateway reference number 15030. See:  http://www.dh.gov.uk/en/Publicationsandstatistics/Lettersandcirculars/Professionalletters/Chiefmedicalofficerletters/DH_121502 (accessed 14 November 2011).

Department of Health. (2011a) Statistical release: Smoking at delivery – Quarter 4 2010/11. See: www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsStatistics/DH_126768 (accessed 14 November 2011).

Department of Health. (2011b) Healthy lives, healthy people: a tobacco control plan for England. See: http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_124917 (accessed 14 November 2011).

Gas Safety Trust. (2010) Carbon monoxide hotspot report 2010. See: http://www.gas-safety-trust.org.uk/carbon-monoxide-hotspot-report-2010
(accessed 14 November 2011).

Godfrey C, Pickett KE, Parrot S. (2010) Estimating the costs to the NHS of smoking in pregnancy for pregnant women and infants. Department of Health Sciences, The University of York: York.

Health Protection Agency. (2009) Carbon monoxide: general information. See: http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1202487036268 (accessed 14 November 2011).

Jones K. (2011) Straight-talking helps mums-to-be quit. The Advisor 2(3): 6-7.

Jones L. (2010) Mum to be escaped the ‘silent killer’. See:
http://www.oldham-chronicle.co.uk/news-features/8/news/59451/mumtobe-escaped-the-silent-killer (accessed 14 November 2011).

Midwifery 2020. (2010) Midwifery 2020: delivering expectations. See: http://www.midwifery2020.org/documents/MW2020_EXEC_SUMMARY_MS_WEB.pdf (accessed 14 November 2011).

NICE. (2010) How to stop smoking in pregnancy and following childbirth. NICE Public Health Guidance 26. NICE: London.

O’Malley M. (2010) Midwives to measure pregnant women’s carbon monoxide levels. See:
http://www.rcm.org.uk/midwives/news/midwives-to-measure-pregnant-womens-carbon-monoxide-levels/?locale=en (accessed 14 November 2011).

Polakowski LL, Akinbami LJ, Mendola P. (2009) Prenatal smoking cessation and the risk of delivering preterm and small for gestational age newborns.
Obstet Gynecol 114(2 pt 1): 318-25.

Royal College of Physicians. (2010) Passive smoking and children: a report of the Tobacco Advisory Group of the Royal College of Physicians. See: http://bookshop.rcplondon.ac.uk/details.aspx?e=305 (accessed 14 November 2011).

The Guardian. (2011) Should there be a compulsory test to detect pregnant smokers? See: http://www.guardian.co.uk/commentisfree/poll/2010/jun/24/health-nhs?INTCMP=SRCH (accessed 14 November 2011).

Usmani CZ, Craig P, Shipton D, Tappin D. (2008) Comparison of CO breath testing and women’s self-reporting of smoking behaviour for identifying smoking during pregnancy. Subst Abuse Treat Prev Policy 3: 4.

Wickham S. (2010) Carbon monoxide testing: what Choice? Essentially MIDIRS. 1(3): 50-1.