Smoking cessation in elective surgical patients offered free nicotine patches at listing: a pilot study.

Free nicotine patches may promote pre-operative smoking cessation. Smokers (≥ 10 cigarettes.day-1 ) awaiting non-urgent surgery were randomly assigned (3:1) to an offer of free nicotine patches or a control group who were not offered free nicotine patches. The suggested regimen lasted 5 weeks, with patch strength decreasing incrementally after 3 and 4 weeks. The primary outcome was smoking abstinence for ≥ 4 weeks, as self-reported by participants on the day of surgery, including, where possible, corroboration using exhaled carbon monoxide testing. Out of 600 included smokers, 447 (74.5%) were randomly assigned to an offer of pre-operative nicotine patches, with 175 (39.1%) of these accepting the offer and 56 (12.5%) using patches for ≥ 3 weeks. Out of 396 participants offered nicotine patches who were included for analysis, 36 (9.1%) quit smoking for ≥ 4 weeks before surgery as compared with 8 (5.9%) controls, OR 1.5 [95%CI 0.7-3.2], p = 0.300. Sixty-three (15.9%) quit smoking for 24 h before surgery as compared with 15 (11.1%) controls, OR 1.4 [95%CI 0.8-2.4], p = 0.200. Participants offered nicotine patches were more likely to engage in a cessation attempt lasting more than 24 h, 46 (11.6%) vs. 5 (3.7%), OR 3.4 [95%CI 1.8-8.8], p = 0.010. Out of 78 participants who quit smoking by the day of surgery and were followed up at 6 months, 46 (59%) had relapsed. Offering free nicotine patches stimulated interest in quitting compared with controls, but our protocol had limited effectiveness.

Concurrent beneficial (vitamin D production) and hazardous (cutaneous DNA damage) impact of repeated low-level summer sunlight exposures.

BACKGROUND: The concurrent impact of repeated low-level summer sunlight exposures on vitamin D production and cutaneous DNA damage, potentially leading to mutagenesis and skin cancer, is unknown. OBJECTIVES: This is an experimental study (i) to determine the dual impact of repeated low-level sunlight exposures on vitamin D status and DNA damage/repair (via both skin and urinary biomarkers) in light-skinned adults; and (ii) to compare outcomes following the same exposures in brown-skinned adults. METHODS: Ten white (phototype II) and six South Asian volunteers (phototype V), aged 23-59 years, received 6 weeks' simulated summer sunlight exposures (95% ultraviolet A/5% ultraviolet B, 1·3 standard erythemal doses three times weekly) wearing summer clothing exposing ~35% body surface area. Assessments made were circulating 25-hydroxyvitamin D [25(OH)D], immunohistochemistry for cyclobutane pyrimidine dimer (CPD)-positive nuclei and urinary biomarkers of direct and oxidative (8-oxo-deoxyguanosine) DNA damage. RESULTS: Serum 25(OH)D rose from mean 36·5 ± 13·0 to 54·3 ± 10·5 nmol L-1 (14·6 ± 5·2 to 21·7 ± 4·2 ng mL-1 ) in phototype II vs. 17·2 ± 6·3 to 25·5 ± 9·5 nmol L-1 (6·9 ± 2·5 to 10·2 ± 3·8 ng mL-1 ) in phototype V (P < 0·05). Phototype II skin showed CPD-positive nuclei immediately postcourse, mean 44% (range 27-84) cleared after 24 h, contrasting with minimal DNA damage and full clearance in phototype V (P < 0·001). The findings did not differ from those following single ultraviolet radiation (UVR) exposure. Urinary CPDs remained below the detection threshold in both groups; 8-oxo-deoxyguanosine was higher in phototype II than V (P = 0·002), but was unaffected by UVR. CONCLUSIONS: Low-dose summer sunlight exposures confer vitamin D sufficiency in light-skinned people concurrently with low-level, nonaccumulating DNA damage. The same exposures produce minimal DNA damage but less vitamin D in brown-skinned people. This informs tailoring of sun-exposure policies.

Early skin and challenge testing after rocuronium anaphylaxis.

We present a case of early skin and challenge testing in a patient following severe anaphylaxis to rocuronium. The patient presented for semi-elective laparoscopic cholecystectomy and developed anaphylaxis with severe cardiovascular collapse after induction of anaesthesia. Surgery was cancelled but was considered necessary before the recommended four to six weeks for formal allergy testing. Limited skin and challenge testing was performed to rocuronium and cisatracurium while the patient was in the intensive care unit to identify a safe neuromuscular blocking drug for subsequent early surgery. The subsequent surgery, 48 hours after the initial reaction, was uneventful. The case highlights the difficulties when anaesthetising patients with recent anaphylaxis who have not yet had formal allergy testing and presents a potential management strategy involving early skin testing.

Sunlight exposure and photoprotection behaviour of white Caucasian adolescents in the UK.

BACKGROUND: Sun exposure has positive and negative effects on health, yet little is known about the sun exposure behaviour of UK adolescents, including those more prone or less prone to sunburn. OBJECTIVE: To examine sun exposure behaviour of UK white Caucasian adolescents including time spent outdoors, holiday behaviour, use of sunscreen and clothing, with assessment for differences between sun-reactive skin type groups. METHODS: White Caucasian adolescents (12-15 years) attending schools in Greater Manchester completed a two-page questionnaire to assess sun exposure and photoprotective behaviour. RESULTS: A total of 133 adolescents (median age 13.4 years; 39% skin type I/II, 61% skin type III/IV) completed the questionnaire. In summer, adolescents spent significantly longer outdoors at weekends (median 4 h/day, range 0.25-10) than on weekdays (2, 0.25-6; P < 0.0001). When at home in the UK during summer, 44% reported never wearing sunscreen compared to just 1% when on a sunny holiday. Sunscreen use was also greater (frequency/coverage) when on a sunny holiday than at home in the UK summer (P < 0.0001). Adolescents of skin types I/II (easy burning) spent significantly less time outdoors than skin types III/IV (easy tanning) on summer weekends (P < 0.001), summer weekdays (P < 0.05) and on a sunny holiday (P = 0.001). Furthermore, skin types I/II reported greater sunscreen use during summer in the UK and on sunny holiday (both P < 0.01), and wore clothing covering a greater skin area on a sunny holiday (P < 0.01) than skin types III/IV. There was no difference in sun exposure behaviour/protection between males and females. CONCLUSION: The greater sun-protective measures reported by adolescents of sun-reactive skin type group I/II than III/IV suggest those who burn more easily are aware of the greater need to protect their skin. However, use of sunscreen during the UK summer is low and may need more effective promotion in adolescents.

Sunlight exposure behaviour and vitamin D status in photosensitive patients: longitudinal comparative study with healthy individuals at U.K. latitude.

BACKGROUND: Low vitamin D status is prevalent in wintertime in populations at northerly latitudes. Photosensitive patients are advised to practise sun avoidance, but their sunlight exposure levels, photoprotective measures and resulting vitamin D status are unknown. OBJECTIVES: To examine seasonal vitamin D status in photosensitive patients relative to healthy individuals and to assess quantitatively behavioural and demographic contributors. METHODS: This was a longitudinal prospective cohort study (53·5°N) examining year-round 25-hydroxyvitamin D [25(OH)D] levels, sun-exposure behaviour and oral vitamin D intake in photosensitive patients diagnosed at a photoinvestigation unit (n = 53), compared with concurrently assessed healthy adults (n = 109). RESULTS: Photosensitive patients achieved seasonal 25(OH)D variation, but insufficient (< 20 ng mL(-1); 50 nmol L(-1)) and even deficient (< 10 ng mL(-1); 25 nmol L(-1)) levels occurred at the summer peak in 47% and 9% of patients, respectively, rising to 73% and 32% at the winter trough. Adjusting for demographic factors, the mean values were lower than for healthy volunteers by 18% [95% confidence interval (CI) 4-29] in summer (P = 0·02) and 25% (95% CI 7-39) in winter (P = 0·01). Behavioural factors explained 25(OH)D differences between cohorts. Patients demonstrated lower weekend ultraviolet B doses (P < 0·001), smaller skin surface area exposure (P = 0·004) and greater sunscreen use (P < 0·001), while average oral vitamin D intake was low in both groups (photosensitive: 2·94 µg per day). Supplementation and summer surface area exposure predicted summer peak and winter trough 25(OH)D levels. A 1 µg per day increment in supplementary vitamin D raised summer and winter 25(OH)D by 5% (95% CI 3-7) and 9% (95% CI 5-12), respectively (both P < 0·001). CONCLUSIONS: Photosensitive patients are, through their photoprotective measures, at high risk of year-round low vitamin D status. Guidance on oral measures should target this patient group and their physicians.

Lifestyle factors including less cutaneous sun exposure contribute to starkly lower vitamin D levels in U.K. South Asians compared with the white population.

BACKGROUND: Long-standing concerns over the vitamin D status of South Asian adults in the U.K. require studies using statistically valid sample sizes to measure annual variation and contributory lifestyle factors. OBJECTIVES: To measure annual variation in the vitamin D status of U.K. South Asians, to determine the associated lifestyle influences, and to compare these with a similar study of white adults. METHODS: A single-centre, prospective cohort study measuring circulating 25-hydroxyvitamin D [25(OH)D], sunlight exposure levels and lifestyle factors for 1 year in 125 ambulant South Asian adults with sun-reactive skin type V, aged 20-60 years, in Greater Manchester, U.K. (53·5°N). RESULTS: The 25(OH)D levels of South Asians were alarmingly low. In summer, their median 25(OH)D level was 9·0 ng mL(-1) , [interquartile range (IQR) 6·7-13·1], falling to 5·8 ng mL(-1) (IQR 4·0-8·1) in winter. This compared with values in the white population of 26·2 ng mL(-1) (IQR 19·9-31·5) in summer and 18·9 ng mL(-1) IQR (11·6-23·7) in winter. Median daily dietary vitamin D was lower in South Asians (1·32 µg vs. 3·26 µg for white subjects) and was compounded by low supplement use. Despite similar times spent outdoors, ultraviolet (UV) dosimeters recorded lower personal UV exposure among South Asians, indicating sun avoidance when outside, while sun exposure diaries recorded lower amounts of skin surface exposure. CONCLUSIONS: The majority of South Asians never reached sufficiency in vitamin D status. Lifestyle differences, with lower oral intake, sun exposure and rates of cutaneous production due to darker skin, indicate that standard advice on obtaining sufficient vitamin D needs modification for the South Asian community in the U.K.

The role of sunlight exposure in determining the vitamin D status of the U.K. white adult population.

BACKGROUND: Vitamin D is necessary for bone health and is potentially protective against a range of malignancies. Opinions are divided on whether the proposed optimal circulating 25-hydroxyvitamin D [25(OH)D] level (≥ 32 ng mL⁻¹) is an appropriate and feasible target at population level. OBJECTIVES: We examined whether personal sunlight exposure levels can provide vitamin D sufficient (≥ 20 ng mL⁻¹) and optimal status in the U.K. public. METHODS: This prospective cohort study measured circulating 25(OH)D monthly for 12 months in 125 white adults aged 20-60 years in Greater Manchester. Dietary vitamin D and personal ultraviolet radiation (UVR) exposure were assessed over 1-2 weeks in each season. The primary analysis determined the post-summer peak 25(OH)D required to maintain sufficiency in wintertime. RESULTS: Dietary vitamin D remained low in all seasons (median 3·27 µg daily, range 2·76-4·15) while personal UVR exposure levels were high in spring and summer, low in autumn and negligible in winter. Mean 25(OH)D levels were highest in September [28·4 ng mL⁻¹; 28% optimal, zero deficient (<5 ng mL⁻¹)], and lowest in February (18·3 ng mL⁻¹; 7% optimal, 5% deficient). A February 25(OH)D level of 20 ng mL⁻¹ was achieved following a mean (95% confidence interval) late summer level of 30·4 (25·6-35·2) and 34·9 (27·9-41·9) ng mL⁻¹ in women and men, respectively, with 62% of variance explained by gender and September levels. CONCLUSIONS: Late summer 25(OH)D levels approximating the optimal range are required to retain sufficiency throughout the U.K. winter. Currently the majority of the population fails to reach this post-summer level and becomes vitamin D insufficient during the winter.

The impact of photosensitivity disorders on aspects of lifestyle.

BACKGROUND: Photosensitivity disorders involve an abnormal skin reaction to sunlight exposure and affect a substantial percentage of the population. No previous studies have directly compared lifestyle attributes between photosensitive and healthy individuals. OBJECTIVES: To assess the impact of photosensitivity on time spent outdoors in the U.K., holiday behaviour, use of sunscreens and vitamin D supplements, and employment status. METHODS: Questionnaires were completed by ambulant photosensitive and healthy adults aged 18-60 years residing in Greater Manchester. RESULTS: Forty-five adults with moderate-severe photosensitivity and 124 healthy adults completed the questionnaire. This revealed that photosensitive subjects spent significantly less time outdoors in the U.K. on both summer weekdays (P < 0·01) and summer weekends (P < 0·0001) than healthy subjects, took fewer holidays per year (P < 0·05), and spent less time outdoors on a sunny holiday (P < 0·0001). They wore clothing that covered a wider skin area (P < 0·0001), and use of sunscreen was greater (both frequency of application and area covered) in the photosensitive group outside of holiday time (P < 0·0001), but not when on a sunny holiday, as healthy people increased their sunscreen use at this time. Despite the reduced sun exposure, photosensitive subjects were no more likely to take vitamin D supplements than healthy subjects were; they also exhibited a significantly higher rate of unemployment (P < 0·05). CONCLUSIONS: Photosensitivity disorders negatively influence lifestyle including employment status; more attention is required to the socioeconomic impact of these conditions.

Management of acute heart failure.

Acute heart failure may be defined as the failure of the circulation to supply the demands of metabolising tissues due to acute cardiac dysfunction. First aid measures aimed at reducing symptomatology should be chosen with respect to their ability to improve cardiac function. The use of diuretics in acute heart failure does not sit well with the principle of improving cardiac function whereas the use of vasodilators does. As with any circulatory disturbance treatment must be guided by appropriate monitoring and the demands of metabolizing tissues must be reduced. Inotropes should be reserved for severe cases where other treatments have failed. This is to avoid the increased myocardial oxygen demand as a result of inotrope use.

Recognizing hypovolaemia.

Clinical shock is a common problem of the critically ill patient. Assessment of the circulating volume is important to assure adequate oxygen supply to the tissues, and hypovolaemia must be treated promptly to avoid organ dysfunction. The author reviews the diagnostic approach, focusing on clinical and "surrogate" markers of volume status. Clinical signs are often late indicators and the monitoring of hemodynamic variables through cardiac catheterism can be misleading. The fluid challenge approach provides a useful diagnostic test of hypovolaemia, and a method for titrating the dose of fluid tailored to the individual's requirement.

Report from the meeting: Gastrointestinal Tonometry: State of the Art. 22nd-23rd May 1998, London, UK.

Gastrointestinal (GI) tonometry, the only clinically available method for the accurate diagnosis of compromised GI blood flow, has been shown to be a sensitive predictor of increased morbidity, mortality and prolonged hospitalization. The recent introduction of the Tonocap, as a means of performing automated air tonometry, has simplified the application of GI tonometry in the clinical setting. Despite this the utility of GI tonometry remains controversial. The GI Tonometry: State of the Art meeting brought together a group of clinicians with a proven track record of research, clinical interest and expertise in this field. The aim of the meeting was to come to a consensus regarding certain issues such as the past and future roles of GI tonometry and standards for its correct usage and interpretation. Finally suggestions as to further research and clinical evaluation were made within a broader discussion regarding the complexities of applying the principles of evidence-based medicine to the introduction of a new piece of medical technology.

The appropriate role of colloids in managing fluid imbalance: a critical review of recent meta-analytic findings.

Three meta-analyses have recently been reported on the relationship between choice of resuscitation fluid and risk of mortality in critically ill patients. The relative risk of death (1.16-1.19) in two of the meta-analyses was slightly higher in colloid than crystalloid recipients; however, this observation was not statistically significant. In the third meta-analysis, 6% (95% confidence interval [CI], 3-9%) pooled excess mortality was documented in patients receiving albumin for hypovolaemia, burns or hypoalbuminaemia. The mortality difference in hypovolaemia patients (4%; 95% CI, 0-8%) was not statistically significant. A variety of serious limitations apply to the three meta-analyses, suggesting that their findings be interpreted cautiously. More than one-half of the randomized controlled trials (RCTs) included in the meta-analyses were reported prior to 1990 and hence do not reflect current practice. Each meta-analysis included only a subset of relevant RCTs, and therefore the scope of inferences to be drawn from the meta-analytic results is limited. The meta-analyses combined RCTs that were notably heterogeneous with respect to patient characteristics, type of illness, administered fluids and physiologic endpoints. Differences in illness severity, concomitant therapies and fluid management approaches were not taken into account. Very few of the RCTs were blinded. The meta-analyses do not support the conclusion that choice of resuscitation fluid is a major determinant of mortality in critically ill patients, nor do they support changes to current fluid management practice. Changes such as exclusive reliance on crystalloids would necessitate a reassessment of the goals and methods of fluid therapy. Since the effect on mortality may be minimal or non-existent, choice of resuscitation fluid should rest on whether the particular fluid permits the intensive care unit to provide better patient care.

Laboratory facilities and recommendations for the characterization of biological ultraviolet dosimeters.

A laboratory facility for characterizing biological dosimeters for the measurement of UV radiation has been built and tested. The facility is based on a solar simulator, stabilized by photofeedback, and monitored by a spectroradiometer, with a versatile filter arrangement. This enables the following characteristics of the dosimeters to be ascertained: spectral response, linearity, and reciprocity; angular acceptance and response; calibration in simulated sunlight. The system has been tested on a variety of dosimeters and has the potential to be used with other radiometers, subject currently to the size of their active surface.

Spectral UV irradiance on vertical surfaces: a case study.

The UV spectral irradiance on horizontal and vertically oriented surfaces was measured throughout a cloudless day (18 July 1995) at Izana station, Tenerife, using a Bentham DTM300 spectroradiometer scanning from 290 to 500 nm in steps of 5 nm. Results show that irradiance measured on a horizontal surface is not proportional to irradiance on a vertical surface. The relation between the two depends upon orientation of the vertical surface, zenith angle and wavelength. At short UVB wavelengths surfaces directed toward the solar azimuth received their maximum irradiances much closer to solar noon than the maxima for longer wavelengths. Some vertical surfaces also received significantly more irradiance than the horizontal surface at long wavelengths during all but the central hours of the day, while at short wavelengths all vertical irradiances were less than the horizontal except for the measurements at the extreme ends of the day. Erythemally effective radiation followed the diurnal pattern of irradiations for short UVB wavelengths.