Optimising Foil Selection for Neutron Activation Systems

Neutron spectrum unfolding using activation foils is currently the primary technique planned for measuring the neutron energy spectrum at the first wall of power-generating fusion reactors. Room for improvement in the effectiveness of current foil selection was identified, and a program produced to select foils procedurally in order to maximise the accuracy of the unfolding procedure. Using Kullback–Leibler Divergence to quantify the accuracy, the spectrum unfolded by the procedurally selected set of foils is found to be more accurate than the spectrum unfolded by a set of foils used in the literature.

Preoperative scar perception study comparing 'scarless' in the neck endoscopic thyroidectomy with open thyroidectomy: a cross-sectional study

INTRODUCTION

Open thyroidectomy is the most common approach to thyroid surgery. However, 'scarless' (in the neck) endoscopic thyroidectomy, consisting of endoscopic and robotic surgery, is progressively being adopted for its perceived cosmetic benefits. This study aims to determine the patient's preferred surgical approach and to identify the factors that influence their decision.

MATERIALS AND METHODS

A pilot study consisting of 100 patients with a surgical thyroid disorder were prospectively recruited from a single tertiary centre. An interviewer-administered survey was conducted. Demographic, socioeconomic status, scar perception and an adapted body image scale were evaluated to identify factors that shaped the patient's perception of the surgical approach.

RESULTS

The mean age of participants was 54.5 ± 13.0 years; 72% were women and 87% Chinese. Of the 100 patients, 75 patients considered scarless endoscopic thyroidectomy as their preferred surgical approach while 25 patients opted for open thyroid surgery. Improvement in scar perception score between scarless endoscopic thyroidectomy and open thyroid surgery is associated with an increased willingness to choose scarless endoscopic thyroidectomy. The mean body image scale score was 6.9 ± 2.8, indicating no statistical difference between the surgical approaches. On multivariate analysis, improvement in scar perception score (odds ratio 3.38, 95% confidence interval 1.11-10.29) and having surgeon recommendation (odds ratio 6.38, 95% confidence interval 1.80-22.63) were independently associated with interest in scarless endoscopic thyroidectomy.

CONCLUSION

Patients interest in undergoing scarless endoscopic thyroidectomy is driven by improved scar perception and surgeon's recommendation compared with open thyroid surgery.

Injuries and envenomation by exotic pets in Hong Kong

INTRODUCTION

Exotic pets are increasingly popular in Hong Kong and include fish, amphibians, reptiles, and arthropods. Some of these exotic animals are venomous and may cause injuries to and envenomation of their owners. The clinical experience of emergency physicians in the management of injuries and envenomation by these exotic animals is limited. We reviewed the clinical features and outcomes of injuries and envenomation by exotic pets recorded by the Hong Kong Poison Information Centre.

METHODS

We retrospectively retrieved and reviewed cases of injuries and envenomation by exotic pets recorded by the Hong Kong Poison Information Centre from 1 July 2008 to 31 March 2017.

RESULTS

There were 15 reported cases of injuries and envenomation by exotic pets during the study period, including snakebite (n=6), fish sting (n=4), scorpion sting (n=2), lizard bite (n=2), and turtle bite (n=1). There were two cases of major effects from the envenomation, seven cases with moderate effects, and six cases with mild effects. All major effects were related to venomous snakebites. There were no mortalities.

CONCLUSION

All human injuries from exotic pets arose from reptiles, scorpions, and fish. All cases of major envenomation were inflicted by snakes.

Clinical Practice and Risk Factors for Immediate Complications of Endotracheal Intubation by Intensive Care Unit Doctors in a Regional Hospital in Hong Kong

Background

Endotracheal intubation in critically ill patients is often challenging and is associated with a high complication rate. Intensive Care Unit (ICU) doctors are often responsible for emergency intubation but local data about their experience is lacking.

Objective

To describe the ICU team's practice of endotracheal intubation in critically ill patients in a regional hospital; to evaluate the incidence of immediate complications; and to identify risk factors for complications and predictors for successful intubation.

Design

Retrospective, observational study

Patients

All patients who received endotracheal intubation by the ICU team of the study centre between the 1st July 2013 and 31st December 2013.

Results

Complete data from 325 endotracheal intubations were analyzed. The commonest diagnosis was pneumonia (41.5%) and the mostly frequently cited indication for endotracheal intubation was respiratory failure (50.8%). Complications occurred in 25.5% of all intubations including 4 cases of cardiac arrest after the procedure. Haemodynamic alterations (hypotension and hypertension occurred in 9.2% and 7.4% respectively) were the most common complications. Overall, 96.6% of intubations were successful on the first two attempts. Logistic regression analyses showed that reduced mouth opening was a significant risk factor for immediate complications (odds ratio [OR] 15.98, 95% confidence interval [CI]: 2.71 to 94.41, P=0.006). Cormack-Lehane laryngoscope grading below 2b (OR 0.2, 95% CI: 0.07-0.59, P=0.003) and operator with more than 6 months of formal anaesthetic training (OR 7.06, 95% CI: 1.63 to 30.62, P=0.009) were independent predictors for successful intubation.

Conclusion

The ICU team achieves a high successful rate of emergency endotracheal intubation. High rates of anticipated and unanticipated difficult airway are encountered. Reduced mouth opening is a significant risk factor for complications occurrence. Cormack-Lehane laryngoscopic grading below 2b and intubation performer with more than 6 months of formal anaesthetic training are significant independent predictors for successful intubation. (Hong Kong j.emerg.med. 2016;23:135-144)

A Case Report of Sodium Hypochlorite Accident

Sodium hypochlorite is widely used as an irrigating solution in dental practice. Despite its safe properties, serious complications can result from inadvertent use. We report a patient presenting to the accident and emergency department for sodium hypochlorite accident during dental root canal therapy. The management of this dental emergency condition is discussed.

A Case of Unintentional Methadone Overdose Followed by Hypoglycaemia

Methadone overdose is expected to result in intoxication simulating the other opioids. We report a case of hypoglycaemia following accidental methadone ingestion. A 21-year-old woman presented to a local accident and emergency department 10 hours after ingestion of 800 mg of methadone. She was found to have coma, respiratory suppression, hypotension, prolonged QTc and hypoglycaemia. The hypoglycaemia was reversed by dextrose replacement. The patient required intubation and inotropic support because of cardio-respiratory instability. She eventually recovered without consequence. To date, this is the first reported case of methadone overdose induced hypoglycaemia.

Acute Coronary Syndrome Secondary to Methylphenidate Overdose

A 28-year-old lady presented to the emergency department after an overdose of methylphenidate. She complained of chest pain and developed an acute coronary syndrome with marked ST segment depression in the electrocardiogram and elevated troponin I level. She was closely monitored in the cardiac care unit and was treated with the standard therapy for acute coronary syndrome. Echocardiogram showed global left ventricle impairment. The follow-up echocardiogram showed that the left ventricular function normalised and the subsequent coronary angiogram was normal. The clinical use, abuse potential, toxicity and overdose treatment of methylphenidate are discussed.

A Case of Fatal Hydroxychloroquine Overdose

A 28-year-old woman ingested 20 g of hydroxychloroquine sulphate for suicidal attempt. She developed hypotension, cardiac conduction disturbance, hypokalemia and hypoglycemia. Despite treatment with mechanical ventilation, epinephrine, sodium bicarbonate, diazepam and potassium replacement, she succumbed 10 hours post-overdose. Previous case reports of hydroxychloroquine overdose are summarised and the therapeutic choices are discussed.

Pneumomediastinum, Surgical Emphysema and Pneumorrhachis after Insufflation of Ketamine

We report a rare complication after ketamine abuse. A 26-year-old known ketamine abuser developed pneumomediastinum, extensive surgical emphysema and pneumorrhachis after ‘snorting’ ketamine. He also suffered from acute on chronic renal failure and liver function impairment due to ketamine use. His pneumomediastinum and subcutaneous emphysema resolved with conservative management. Pneumomediastinum is a well-reported complication after illicit drug use, particularly smoking ‘crack’ cocaine. This case illustrates that such complication may also occur in ketamine abuse.

One More ‘T’ for the Mnemonic of the Management of Pulseless Electrical Activity: Tension Pneumoperitoneum

The approach in Advanced Cardiac Life Support provided by the American Heart Association and the European Resuscitation Council guidelines for the management of pulseless electrical activity emphasizes on the search of reversible causes. Tension pneumoperitoneum is an uncommon surgical emergency encountered in the accident and emergency department. We report a case of pulseless electrical activity secondary to tension pneumoperitoneum in an elderly woman. Restoration of spontaneous circulation was immediately achieved after needle decompression. The management of tension pneumoperitoneum is discussed.

A Case of Pyrethroid Poisoning with Clinical Presentation Mimicking Organophosphate Poisoning

We report an 89-year-old retired farmer with prolonged bradycardia and hypotension after pyrethroid insecticides ingestion in a suicidal attempt. This patient also had a clinical manifestation mimicking organophosphate poisoning, included confusion, lacrimation and salivation. He required intensive care support, atropine and inotrope infusions treatments. Only metabolites of synthetic pyrethroid insecticides (3-phenoxybenzoic acid and 3-phenoxybenzaldehyde) were detected in the urine sample. In the serum toxicology screening, specific analysis for organophosphate pesticides was negative. He eventually recovered without major sequela. (Hong Kong j.emerg.med. 2016;23:47-51)

Metabolic Acidosis Complicating Ingestion of Disinfectant Floor Cleaner Containing Butoxyethanol

Butoxyethanol intoxication has seldom been reported. We describe a case of ingestion of butoxyethanol-containing cleaner resulting in high anion gap metabolic acidosis, which resolved after treatment with ethanol and haemodialysis. The presentations and treatments of previous cases are highlighted. Discussion is centred on the toxicological pathway of butoxyethanol and the role of alcohol dehydrogenase inhibitor.

Two Cases of Chloral Hydrate Overdose

Chloral hydrate overdose is associated with cardiac toxicities, gastrointestinal tract injuries, central nervous system and respiratory depression. Among all the complications, cardiac arrhythmias are particularly concerning and frequently reported in the literature. The majorities of fatalities from chloral hydrate overdose are due to refractory cardiac arrhythmia. Chloral hydrate-induced arrhythmias are resistant to most of the standard anti-arrhythmic agents but have good response to propranolol. We report two cases of severe chloral hydrate overdose presenting with alarming cardiac rhythm disturbances. One of the patients was successfully treated with intravenous propranolol in the accident and emergency department. The management of chloral hydrate overdose in particular to its cardiac toxicity is reviewed.

A Manikin Study Comparing McGrath Mac® and Airtraq® with Macintosh Laryngoscope in Tracheal Intubation by Intensive Care Unit Doctors

Objective

To compare the performance of the McGrath Mac® and the Airtraq® with the Macintosh laryngoscope for tracheal intubation.

Design

A manikin study with different simulated difficult airway scenarios.

Methods

Thirty intensive care unit (ICU) doctors (10 specialists and 20 non-specialists) performed intubation by using the 3 airway devices in the manikin with (i) normal airway, (ii) cervical rigidity, and (iii) tongue oedema. The intubation time, success rate, oesophageal intubation and number of episodes of dental injury were measured and compared.

Results

The mean intubation time was significantly less by using the Airtraq® comparing to the McGrath Mac® in the manikin with normal airway (12.77 sec vs. 24.23 sec; p<0.001). Similarly, the mean intubation time was less by using Airtraq® when comparing to the McGrath Mac® in the manikin with cervical rigidity (12.73 sec vs. 17.5 sec; p=0.013). In the scenario of simulated tongue oedema, the mean intubation time of Airtraq® was shorter than Macintosh laryngoscope (24.83 sec vs. 34.20 sec; p=0.011) while there was no difference between Airtraq® and the McGrath Mac®. Less dental injury was noted when using the Airtraq® compared to the Macintosh laryngoscope in simulated cervical rigidity (p=0.005) and tongue oedema (p<0.001). Less dental injury was also noted when using the McGrath Mac® compared to the Macintosh laryngoscope in simulated tongue oedema (p<0.001).

Conclusion

Even with prior limited experience in using the McGrath Mac®, the performance of tracheal intubation by using this new device is comparable with the Airtraq®. The McGrath Mac® can be a good alternative for tracheal intubation in difficult airway situations. (Hong Kong j.emerg.med. 2015;22:337-344)

Two Cases of the Purple Urine Bag Syndrome

The purple urine bag syndrome, purple discoloration of urine, is an uncommon and alarming condition in patients requiring long-term urinary catheterization but the clinical course is usually benign. We report two cases of the syndrome with a literature review on its aetiology and management.

A Case Report of Ocular Injury by Euphorbia Plant Sap

Ocular injuries in the working place are usually related to exposure to industrial chemical substances e.g. acid and alkaline, radiation energy e.g. ultra-violet light or even direct trauma. Ocular injuries by saps of plants are uncommon but can result in serious ocular complications. We report a case of ocular injury of a gardener caused by the sap of a Euphorbia plant, Euphorbia trigona. The ocular complications and management of Euphorbia plant sap-associated eye injuries are reviewed.

Chemical Necrotising Fasciitis Secondary to Self-Injection of Permethrin Insecticide

We report a 65-year-old male with chemical necrotising fasciitis after self-injection of permethrin insecticide. The patient also developed persistent hypoglycemia secondary to massive insulin overdose. There was no evidence of systemic toxicities from the insecticide poisoning. Multiple debridement and skin grafting were performed over his right forearm due to extensive tissue damage. He eventually recovered with impairment of his right hand function. The clinical features and the management of this uncommon route of insecticide poisoning are discussed. (Hong Kong j.emerg.med. 2011;18:441-445)

An Uncommon Cause of Deep Vein Thrombosis: Mycotic Aneurysm Secondary to Salmonella Arteritis

Mycotic aneurysm is an uncommon surgical emergency with high mortality. Endovascular infection due to salmonella is the commonest cause of intra-abdominal mycotic aneurysm. We report a rare presentation of mycotic aneurysm in a 78-year-old man who presented to the accident and emergency department with deep vein thrombosis due to compression of the iliac vein by a mycotic aneurysm arising from the internal iliac artery and an adjacent abscess. A comprehensive review of the aetiology, clinical presentation and management of mycotic aneurysm secondary to salmonella arteritis is presented.

Sibutramine Associated Cardiac Arrest in a Chinese Healthy Young Lady

Sibutramine is a slimming agent and acts on reducing appetite and increasing satiety. It was withdrawn from the market world-wide, including Hong Kong, since November 2010 due to its side effects on the cardiovascular system. However, sibutramine is still commonly found as adulterant in the slimming medications which could be bought from internet or over-the-counter. A Chinese healthy young lady developing sudden cardiac arrest after taking sibutramine for weight reduction is described.

The Use of Glucagon and other Antidotes in a Case of Beta-Blocker and Calcium Channel Blocker Overdose

We report a case of metoprolol and nifedipine overdose complicated by hypotension which responded to intravenous boluses of calcium chloride and glucagon. The blood pressure was subsequently stabilised by continuous glucagon infusion with the aid of an insulin-dextrose drip. The discussion is focused on the role of antidotes and catecholamine inotropes in the management of beta-blocker and calcium channel blocker poisoning.

Clinical Experience in the Use of Intravenous Lipid Emulsion in Hydroychloroquine and Chloroquine Overdose with Refractory Shock

Hydroxychloroquine overdose is a rare condition and often results in severe cardiovascular toxicities. We report 2 cases of fatal hydroxychloroquine overdose (1 patient had co-ingestion of chloroquine). Both patients developed refractory cardiovascular collapse and cardiac arrest soon after the drug overdose. Both of them were treated with high dose adrenaline and diazepam. However, they deteriorated rapidly despite the treatments. In view of similar toxicological profile of hydroxychloroquine to other lipophilic cardiotoxic medications, intravenous lipid emulsion was given as the last resort but both of them died eventually. Based on the clinical experience from these 2 cases, Intravenous lipid emulsion is not effective in reversing the cardiotoxic effects of hydroxychloroquine and chloroquine overdose.

Two Cases of Gelsemium Elegans Benth. Poisoning

A couple of spouse mistook the Gelsemium elegans Benth. collected in countryside for Mussaenda pubescens Ait. f. and suffered toxicity soon after ingestion. One went into respiratory failure necessitating intubation and the other developed dizziness. The morphological differences between Gelsemium elegans Benth. and Mussaenda pubescens Ait. f. may not be easily recognised by the general public. Close monitoring and respiratory support are the cornerstones of management.

A Case of Penetrating Neck Injury with Retained Foreign Body in the Cervical Vertebral Body and Vertebral Artery Dissection

Vertebral artery injury is an uncommon but life-threatening condition. We report a young lady with penetrating neck injury, after stabbed by her husband with a ceramic knife, resulting in right C5 nerve root injury and vertebral artery dissection. The tip of the knife was retained in the cervical vertebral body. Embolisation of the proximal vertebral artery was performed before the removal of the retained knife tip. The nerve root injury was successfully repaired and the patient had only minimal proximal weakness after the operation. The management of penetrating neck trauma with vertebral artery injury is discussed.

Systemic Poisoning after Mucosa and Skin Contact of Paraquat

Paraquat poisoning is associated with very high mortality and often results in severe complications including pulmonary fibrosis and multi-organ failure. Majorities of the reported cases had paraquat exposure from oral route either due to accidental intake or suicidal attempt. Systemic complications from dermal exposure were infrequently reported. We reported a patient suffering from acute renal failure and liver function derangement due to systemic absorption of paraquat from accidentally dermal and mucosal contact. The case has illustrated the danger of improper use of this high toxic substance as a household product.

A Case of Acute Insulin Poisoning

A 32-year-old lady presented to the emergency department for suicidal attempt by self-injection of insulin (Protaphane 210 units). She developed repeated episodes of hypoglycaemia even with continuous intravenous infusion of 10% dextrose solution during observation. However, she did not develop serious complications of hypoglycaemia and was subsequently discharged after conservative treatment. Acute insulin poisoning is uncommon. The management of this uncommon poisoning is reviewed in this case report.

Case Series of Paraquat Poisoning in Tuen Mun Hospital

Paraquat is highly toxic to human and is widely used in agriculture as a contact herbicide. However, it is easily accessible in agricultural product shops. Seven cases of paraquat poisoning were treated in Tuen Mun Hospital from 1998–2005. The mortality (4 out of 7) was very high. One patient died after oral exposure to paraquat despite immunosuppressive and antioxidant therapies. The mechanism of toxicity and potential new therapies of paraquat poisoning are discussed in the article.

Penetrating Atherosclerotic Ulcer - an Increasingly Recognized Entity of the Acute Aortic Syndrome: Case Report and Literature Review

With the advance in diagnostic radiology, penetrating atherosclerotic ulcers of the aorta become increasingly recognised in our daily practice. However, their natural history and treatment are not well defined. We report a case of penetrating atherosclerotic ulcer at the aortic arch and review the literature.

Emergency Critical Care Service in Emergency Medicine Ward: The Experience in North Lantau Hospital

With the increased demand of critical care, emergency physicians often provide a significant proportion of critical care for the critically ill patients apart from their primary roles in resuscitation and initial stabilisation. The dual training pathway of emergency medicine and intensive care medicine enables the Accident and Emergency Departments (AEDs) to be staffed with emergency intensivist to provide care of critically ill patients in the AEDs beyond the initial resuscitation. North Lantau Hospital is a community hospital located in central Tung Chung of Lantau Island. Transporting critically ill patients to the nearest tertiary hospital requires a significant amount of time which poses high risk to them. An “Emergency Critical Care Management” pilot program was created under these circumstances. In this pilot program, up to 2 beds in the Emergency Medicine Ward (EMW) are used for managing critically ill patients. The experience and preliminary outcomes of implementing critical care service in the EMW are shared in this article.

Comparison of green pit viper and Agkistrodon halys antivenom in inhibition of coagulopathy due to Trimeresurus albolabris venom: an in-vitro study using human plasma

INTRODUCTION

There are two antivenoms that may be administered in Hong Kong following a bite by Trimeresurus albolabris: the green pit viper antivenom from the Thai Red Cross Society in Thailand and the Agkistrodon halys antivenom from the Shanghai Institute of Biological Products in China. Both are recommended by the Central Coordinating Committee of Accident and Emergency Services of the Hospital Authority for treating patients with a bite by Trimeresurus albolabris. The choice of which antivenom to use is based on physician preference. This study aimed to compare the relative efficacy of the two antivenoms.

METHODS

This in-vitro experimental study was carried out by a wildlife conservation organisation and a regional hospital in Hong Kong. Human plasma from 40 adult health care worker volunteers was collected. The Trimeresurus albolabris venom was added to human plasma and the mixture was assayed after incubation with each antivenom (green pit viper and Agkistrodon halys) using saline as a control. Fibrinogen level and clotting time in both antivenom groups were studied.

RESULTS

The mean fibrinogen level was elevated from 0 g/L to 2.86 g/L and 1.11 g/L after the addition of green pit viper antivenom and Agkistrodon halys antivenom, respectively. When mean clotting time was measured, the value was 6.70 minutes in the control, prolonged to more than 360 minutes by green pit viper antivenom and to 19.06 minutes by Agkistrodon halys antivenom.

CONCLUSIONS

Green pit viper antivenom was superior to Agkistrodon halys antivenom in neutralisation of the thrombin-like and hypofibrinogenaemic activities of Trimeresurus albolabris venom.

Prognostic value of pretreatment circulating neutrophils, monocytes, and lymphocytes on outcomes in lung stereotactic body radiotherapy

PURPOSE

In the present study, we determined the association of pretreatment circulating neutrophils, monocytes, and lymphocytes with clinical outcomes after lung stereotactic body radiotherapy (sbrt).

METHODS

All patients with primary lung cancer and with a complete blood count within 3 months of lung sbrt from 2005 to 2012 were included. Overall survival (os) was calculated using the Kaplan-Meier method. Factors associated with os were investigated using univariable and multivariable Cox proportional hazards regression. Fine-Gray competing risk regression was performed to test the association of the neutrophil:lymphocyte (nlr) and monocyte:lymphocyte (mlr) ratios with two types of failure: disease-related failure and death, and death unrelated to disease.

RESULTS

Of the 299 sbrt patients identified, 122 were eligible for analysis. The median and range of the nlr and mlr were 3.0 (0.3-22.0) and 0.4 (0.1-1.9) respectively. On multivariable analysis, sex (p = 0.02), T stage (p = 0.04), and nlr (p < 0.01) were associated with os. On multivariable analysis, T stage (p < 0.01) and mlr (p < 0.01) were associated with disease-related failure; mlr (p = 0.03), nlr (p < 0.01), and sbrt dose of 48 Gy in 4 fractions (p = 0.03) and 54 Gy or 60 Gy in 3 fractions (p = 0.02) were associated with disease-unrelated death. Median survival was 4.3 years in the nlr≤3 group (95% confidence interval: 3.5 to not reached) and 2.5 years in the nlr>3 group (95% confidence interval: 1.7 to 4.8; p < 0.01).

CONCLUSIONS

In lung sbrt patients, nlr and mlr are independently associated with os and disease-unrelated death. If validated, nlr and mlr could help to identify patients who would benefit most from sbrt.