Background: This study aimed to compare the efficacy, acceptance and side effects of intramuscular tramadol and ketorolac in combination with oral paracetamol in the emergency setting. Materials and methods: This was a randomised, double blind controlled trial. Patients aged 18 years or above with moderate to severe musculoskeletal pain were recruited. Patients with known allergy, currently on psychiatric medication, with alcohol or opioid dependence, during pregnancy and with major systemic illness were excluded. Tramadol 100 mg or ketorolac 30 mg was given intramuscularly together with paracetamol 500 mg per oral. They were then bed rested in the observation ward for one hour. Visual analogue scale (VAS), satisfaction score, vital signs and side effects were recorded. Results: Altogether, 78 (M: 43, F: 35) subjects were recruited from June to September 2005, with equal number in each arm. The mean age was 39.9 for the tramadol group and 43.9 for the ketorolac group. Most of them suffered from back pain (66.7%). There was a significant difference in VAS improvement between the two groups (0.88; P=0.01). However, there were no significant differences in patients' satisfaction score and admission rate. The incidence of side effects was similar between the two groups (tramadol 19, ketorolac 17), mainly dry mouth, and none were major. The tramadol group had more nausea. Conclusion: The analgesic effect of the tramadol and paracetamol combination is as effective as the ketorolac and paracetamol combination. Tramadol is well tolerated and relatively safe. It is also cheaper than ketorolac. Hence, we recommend tramadol and paracetamol combination for acute moderate to severe musculoskeletal pain in the emergency setting.

To study the local epidemiology and clinical presentation after ingestion of oral mucosal irritating plants. Methodology: Cases presenting with immediate oral mucosal irritation after plant product ingestion from July 2005 to June 2009 were retrieved from the Hong Kong Poison Information Centre's clinical database. Their clinical features and management were reviewed. Results: Thirty cases were retrieved and analysed, including 14 males and 16 females. Poisoning occurred all year round with no seasonal predilection. Vomiting and dysphagia were the two most common symptoms other than immediate oral mucosal irritation. Half of the cases could be managed with symptomatic treatment and discharged after a few hours of observation. Six patients presented with angioedema and were managed initially with the use of intravenous steroid, antihistamine and with or without adrenaline. Urgent airway assessment with laryngoscope was performed in 3 patients. No patient required endotracheal intubation. Conclusion: Oral mucosal irritating plant ingestion is not uncommon in Hong Kong. Its clinical feature can mimic angioedema on presentation. Immediate and localized oral mucosal symptoms after plant product ingestion are the key to diagnosis.

The purpose of this study was to evaluate the serum level of salicylate after topical application of methylsalicylate (analgesic balm), and to determine the safety of its use in our population. Methods: This was a human volunteer study involving six volunteers. Each of them applied 10 grams of analgesic balm (containing 5 grams of methylsalicylate) on the limbs, and serial serum salicylate levels were measured just before the trial, and 1, 2, 4 and 8 hours after application. The time required to reach the maximum blood level after application was recorded. Results: The serum salicylate level ranged from non-detectable level up to near therapeutic level in different subjects. The maximum salicylate level measured was 130 mg/L in one of the volunteers 8 hours after application. The calculated systemic bioavailability of dermal methylsalicylate in our study was 19-45%, which was comparable to previous studies. Conclusions: Dermal application of massive amount of analgesic balm may cause unpredictable absorption of methylsalicylate. Patients and physicians should be aware of its potential risk.

Lau Fei Lung, FRCP(Edin), FHKCEM, FHKAM(Emergency Medicine)We report a 29-year-old lady who developed confusion, agitation and seizure after the ingestion of a selfmixture of 3 grams of lidocaine with antacid for treatment of dyspepsia. She developed two episodes of seizure requiring diazepam, propofol and intubation .There was no significant cardiac toxicity and she was discharged on day 3. This is the first reported adult case of seizure in the literature after intentional ingestion of lidocaine for treatment of dyspepsia. The use of local anaesthetic in gastrointestinal cocktail for dyspepsia and its safety are highlighted. Advances in the management of local anaesthetic overdose are also discussed. (Hong Kong j.emerg.med. 2009;16:41-45) 29 3

A 57-year-old woman presented with abdominal distension and vomiting two days after overdosing an unknown amount of sustained-release nifedipine tablets. She had refractory shock requiring calcium chloride, glucagon, insulin-glucose and multiple high-dose inotropic agent infusions in the intensive care unit. Her abdominal computed tomography showed features of bowel ischaemia and exploratory laporotomy reviewed non-salvageable massive bowel ischaemia. She finally succumbed after 22 days of hospital treatment. This case illustrates the importance of awareness of this potentially fatal complication of calcium channel blocker overdose, requiring early recognition and intervention. (Hong Kong j.emerg.med. 2010;17:360-363) 57 − 22