Subcutaneous injection of metallic mercury

Deliberate self-injection of metallic mercury into subcutaneous tissue is uncommon. A 41-year-old lady with a history of schizophrenia was admitted to our hospital after deliberate injection of metallic mercury into her right wrist and antecubital fossa. Physical examination was unremarkable except for the injection marks over right antecubital fossa and wrist. The presence of subcutaneous mercury deposits in her right elbow and wrist was confirmed by X-rays and ultrasound scan. Three days later, erythema, swelling, induration and tenderness were seen over the injection sites. At the operation on day 9, mercury streaks were seen within the brachialis muscle belly, surrounded by friable necrotic tissues along the tract. A similar picture was noted in her right wrist. The necrotic tissues and mercury streaks were removed. The patient had been unco-operative and she only received incomplete treatment with dimercaprol and 2,3-dimercaptosuccinic acid. Her total blood mercury level (normal < 50 nmol/L) decreased from 101-151 nmol/L in the first two weeks to 42 nmol/L 3 months later. Her 24-hour urinary mercury excretion (normal < 10 nmol) changed from 55.7-209.5 nmol in the first 7 weeks to 125.4 nmol 3 months later. This case illustrates that soft tissue metallic mercury can produce local necrosis and may allow continuous absorption with persistent elevations in blood and urinary mercury levels. Therefore, early surgical removal of subcutaneous mercury deposits is required to prevent local complications and minimize the risk of systemic absorption and toxicity.

Relationship of urinary sodium/potassium excretion and calcium intake to blood pressure and prevalence of hypertension among older Chinese vegetarians

OBJECTIVE

To examine the associations of dietary sodium and potassium, as reflected by the urinary sodium/potassium excretion, and calcium intake with blood pressure and the prevalence of hypertension among older Chinese vegetarians in Hong Kong.

DESIGN

Cross-sectional study.

SETTING

Research clinic in a teaching hospital in Hong Kong.

SUBJECTS

A total of 111 ambulatory vegetarians over the age of 55 were recruited from members of religious organizations or old age hostels.

MAIN OUTCOME MEASURES

Hypertension was defined as supine blood pressure >140/90 mmHg or a history of hypertension. Dietary sodium, potassium and calcium intakes were assessed by 24 h recall method or fasting urinary sodium or potassium/creatinine ratios.

RESULTS

Seventy-one subjects (64%) were found to have hypertension. Compared with normotensive subjects, hypertensive subjects had lower calcium intake (411+/-s.d. 324 vs 589+/-428 mg, P=0.04), but higher urinary sodium/creatinine ratio (32.6+/-19.3 vs 21.0+/-12.4, P=0.00) and sodium/potassium ratio (4.7+/-2.8 vs 3.4+/-2.3, P=0.02). Among 88 subjects not taking diuretics or antihypertensive drugs, systolic blood pressure was related to calcium intake (r=-0.40), urinary sodium/creatinine ratio (r=0.39), urinary sodium/potassium ratio (r=0.30) and age (r=0.23). Diastolic blood pressure was related to urinary sodium/creatinine (r=0.29). Twenty-three subjects with high urinary sodium/potassium and low calcium intake and 16 subjects with low urinary sodium/potassium ratio and high calcium intake differed markedly with respect to systolic blood pressure (159+/-26 vs 130+/-15 mmHg) and prevalence of hypertension (78% vs 25%).

CONCLUSIONS

Older Chinese vegetarians are predisposed to hypertension because of their sodium-rich but calcium-deficient diets.

Arthritis treatment in Hong Kong--cost analysis of celecoxib versus conventional NSAIDS, with or without gastroprotective agents

BACKGROUND

Selective cyclo-oxygenase-2 inhibitors have been reported to cause fewer gastrointestinal complications when compared with conventional, non-selective, non-steroidal anti-inflammatory drugs (NSAIDs).

AIM

To analyse the cost of celecoxib (selective cyclo-oxygenase-2 inhibitor) and conventional NSAID regimens for the treatment of osteoarthritis and rheumatoid arthritis from the perspective of a public health organization in Hong Kong.

METHODS

A decision tree was used to analyse the cost of celecoxib, NSAID alone, NSAID plus histamine2-receptor antagonist, NSAID plus misoprostol and NSAID plus proton pump inhibitor over 6 months. Model outcomes were no gastrointestinal toxicity, gastrointestinal discomfort, symptomatic ulcer, anaemia with occult bleeding and serious gastrointestinal complications. The clinical probabilities were estimated from clinical trials. Resource utilization for gastrointestinal events was determined locally. Sensitivity analysis was performed.

RESULTS

The 6-month costs per base-case analysis were as follows: NSAID plus histamine2-receptor antagonist, 1404 HK dollars (1 US dollar = 7.8 HK dollars); celecoxib, 1545 HK dollars; NSAID alone, 1610 HK dollars; NSAID plus misoprostol, 2213 HK dollars; NSAID plus proton pump inhibitor, 2857 HK dollars. The model was sensitive to the patients' underlying gastrointestinal risk scores, daily cost of NSAID regimen, risk ratio of NSAID plus histamine2-receptor antagonist for symptomatic ulcer, daily cost of celecoxib and daily cost of histamine2-receptor antagonist.

CONCLUSIONS

Celecoxib appeared to be the least costly alternative in patients with intermediate to high gastrointestinal risk for the treatment of osteoarthritis and rheumatoid arthritis in Hong Kong.

Herbal medicine causing likely strychnine poisoning

'Maqianzi' (the dried ripe seed of Strychnos nux-vomica L.) contains 1.0-1.4% each of strychnine and brucine. After processing to reduce its toxicity, 'maqianzi' was used as a herbal remedy for rheumatism, musculoskeletal injuries and limb paralysis. A 42-year old woman with neck pain was prescribed 15 g of 'maqianzi' to be taken in two doses at 7 hours apart, although the recommended dose was 0.3-0.6 g. She was apparently well after drinking the first of two bowls of 'maqianzi' decoction. One hour after she drank the second bowl of herbal decoction, she suddenly developed tonic contractions of all her limb muscles and carpopedal spasm lasting 5 min, difficulty in breathing, chest discomfort and perioral numbness. The second bowl of decoction probably became more concentrated because of evaporation of water during continued boiling and contained a larger amount of 'maqianzi'. On arrival in the hospital 1 hour later, she complained of muscle pain and tiredness. She was found to have hyperventilation and weakness of four limbs, with muscle power of grade 5(-)/5. All her symptoms gradually subsided over the next few hours. This case illustrated that 'maqianzi' can cause strychnine poisoning even after processing, especially when the recommended dose is greatly exceeded. In any patient with 'unexplained' muscle spasms or convulsions, strychnine poisoning should be included in the differential diagnosis and they should be asked about the use of herbal medicines.

Obesity and cardiovascular risk factors in Hong Kong Chinese

The purpose of this cross-sectional study was to examine the risk associations between obesity indexes [body mass index (BMI) and waist circumference (WC)], cardiovascular risk factors [plasma glucose and lipids, blood pressure and urinary albumin excretion (UAE)] and morbidity conditions (Type 2 diabetes mellitus, hypertension, dyslipidaemia and/or albuminuria) in Hong Kong Chinese. Seven-hundred and two Hong Kong Chinese subjects (18-65 years of age, 59.4% of whom had at least one morbidity condition) were recruited from the Prince of Wales Hospital, Hong Kong SAR. The measurements taken of the subjects included: height; weight; waist and hip circumferences; blood pressure; fasting plasma glucose and lipids; and 24-h UAE. The mean BMI was 22.4 and 25.7 kg m(-2) in healthy subjects and patients, respectively. The mean WC measurements of healthy subjects and patients were 77.1 and 86.4 cm in males and 71.0 and 81.8 cm in females, respectively. There were increasing trends between obesity indexes and the severity of cardiovascular risk factors and the prevalence of morbidity conditions (all P-values for trend <0.05). Using 19.0-20.9 kg m(-2) and <70 cm as a referent, subjects with a BMI of > or =25.0 kg m(-2) (in both sexes) and/or a WC of > or =85 cm in males and > or =75 cm in females had an age-adjusted odds ratio between 3.2 and 4.4 for the occurrence of at least one morbidity condition. Patients with a greater number of comorbidities also had higher BMI and WC measurements (all P-values for the trend were <0.05 with adjustment for age and gender). Hence, despite Hong Kong Chinese being less obese than Caucasians, the intimate relationships among obesity, cardiovascular risk factors and morbidity conditions remain. Our data support using lower BMI and WC levels to define obesity and its associated health risks rather than using the criteria established from Caucasians who generally have larger body frames.

Ingestion of medicated oils by adults: the risk of severe salicylate poisoning is related to the packaging of these products

Ingestion of medicated oils containing methyl salicylate poses the threat of severe, rapid-onset salicylate poisoning. In this retrospective study of 24 adults who had ingested 'White Flower Oil' (n=18) or 'Red Flower Oil' (n=6), the main objective was to determine if the risk of severe salicylate poisoning was related to the product packaging. 'Red Flower Oil' had a large bottle opening so that its content could be emptied much more easily. It also had a larger bottle size and usually had a higher methyl salicylate concentration than 'White Flower Oil'. Patients tended to ingest a greater amount of 'Red Flower Oil' than 'White Flower Oil'. Five per cent of subjects who had taken 'White Flower Oil', but 67% of subjects who had taken 'Red Flower Oil', had admission plasma salicylate level >2.2 mmol/L (P=0.006). None of the subjects who had ingested 'White Flower Oil', but 50% of subjects who had taken 'Red Flower Oil', had moderate to severe symptoms (P=0.010). As a result, none of the subjects who had ingested 'White Flower Oil', but 33% of subjects who had taken 'Red Flower Oil', required urine alkalinization (P=0.054). One patient who had taken 'Red Flower Oil' died because of hospital-acquired pneumonia. All other patients made a complete recovery. To reduce the amount of methyl salicylate that can be readily swallowed during accidental or deliberate ingestion of medicated oils, improvements are needed in the existing packaging of these products.