Prognosticating Clinical Prediction Scores Without Clinical Gestalt for Patients With Chest Pain in the Emergency Department.

BACKGROUND: Assessment of patients with chest pain is a regular challenge in the emergency department (ED). Recent guidelines recommended quantitative assessment of ischemic risk by means of risk scores. OBJECTIVE: Our aim was to assess the performance of Thrombosis in Myocardial Infarction (TIMI); Global Registry of Acute Coronary Events (GRACE); history, electrocardiogram, age, risk factors, and troponin (HEART) scores; and the North America Chest Pain Rule (NACPR) without components of clinical gestalt in predicting 30-day major adverse cardiac events (MACE). METHODS: We performed a prospective cohort study in adult patients who attended the ED with undifferentiated chest pain. Clinical prediction rules were applied and calculated. The clinical prediction rules were modified from the original ones, excluding components requiring judgment by clinical gestalt. The primary outcome was MACE. Performance of the tests were evaluated by receive operating characteristic curves and the area under curves (AUC). RESULTS: There were 1081 patients included in the study. Thirty-day MACE occurred in 164 (15.2%) patients. The AUC of the GRACE score was 0.756, which was inferior to the TIMI score (AUC 0.809) and the HEART score (AUC 0.845). A TIMI score ≥ 1 had a sensitivity of 97% and a specificity of 45.7%. A GRACE score ≥ 50 had a sensitivity of 99.4% and a specificity of 7.5%. A HEART score ≥ 1 had a sensitivity of 98.8% and a specificity of 11.7%. The NACPR had a sensitivity of 93.3% and a specificity of 51.5%. CONCLUSIONS: Without clinical gestalt, the modified HEART score had the best discriminative capacity in predicting 30-day MACE.

Presenting hydrothorax predicts failure of needle aspiration in primary spontaneous pneumothorax.

OBJECTIVE: The objective was to evaluate if existence of hydrothorax in initial chest radiograph predicts treatment outcome in patients with primary spontaneous pneumothorax who received needle thoracostomy. METHODS: This is a retrospective cohort study carried out from January 2011 to August 2014 in 1 public hospital in Hong Kong. All consecutive adult patients aged 18years or above who attended the emergency department with the diagnosis of primary spontaneous pneumothorax with needle aspiration performed as primary treatment were included. Age, smoking status, size of pneumothorax, previous history of pneumothorax, aspirated gas volume and presence of hydropneumothorax in initial radiograph were included in the analysis. The outcome was success or failure of the needle aspiration. Logistic regression was used to identify the predicting factors of failure of needle aspiration. RESULT: There were a total of 127 patients included. Seventy-three patients (57.5%) were successfully treated with no recurrence upon discharge. Among 54 failure cases, 13 patients (10.2%) failed immediately after procedure as evident by chest radiograph and required second treatment. Forty-one patients (32.3%) failed upon subsequent chest radiographs. Multivariate logistic regression showed factors independently associated with the failure of needle aspiration, which included hydropneumothorax in the initial radiograph (odds ratio [OR]=4.47 [1.56i12.83], P=.005), previous history of pneumothorax (OR=3.92 [1.57-9.79], P=.003), and large size of pneumothorax defined as apex-to-cupola distance ≥5cm (OR=2.75 [1.21-6.26], P=.016). CONCLUSIONS: Hydropneumothorax, previous history of pneumothorax, and large size were independent predictors of failure of needle aspiration in treatment of primary spontaneous pneumothorax.

A cross-sectional survey of snake oral bacterial flora from Hong Kong, SAR, China.

OBJECTIVE: To determine the pattern of oral bacterial flora and their sensitivity to antibiotics in freshly captured native snakes in Hong Kong SAR, People's Republic of China. METHODS: Healthy native snakes were captured and kept in a designated centre. Snake species were identified by experienced herpetologists. Mouth swabs were taken by the veterinarian using strict aseptic techniques. The snakes were released back to the wild immediately after the above procedure. Swabs were sent for microbiological studies of bacterial culture and antibiotic sensitivity. RESULTS: 47 venomous snakes of the families Colubridae, Elapidae and Viperidae and 53 non-medically important snakes were captured. 406 bacterial isolates of 72 different species were cultured: these included gram negative and positive bacterial species and also anaerobic bacterial species. With the exception of the white-lipped pit viper (Cryptelytrops albolabris), venomous snakes harboured more pathogenic bacteria and total bacteria species compared to the non-medically important species. Of the venomous snakes, the Chinese cobra (Naja atra) harboured the largest number of bacterial species. In the present study, all gram negative bacteria associated with wound infection were sensitive to levofloxacin, netilmicin and piperacillin/tazobactam. Many gram negative bacteria in the study were not sensitive to cefuroxime axetil. Amoxicillin/clavulanic acid was an appropriate choice to cover Enterococcus faecalis and anaerobes. CONCLUSION: In the presence of wound infection from snakebite injury in Hong Kong, first line empirical antibiotics include amoxicillin/clavulanic acid plus levofloxacin. Prophylactic antibiotics may be considered in selected cases of Chinese cobra (N. atra) bite, otherwise prophylactic antibiotics are not recommended in snakebite unless tissue necrosis is present.

Local antivenom treatment for ophthalmic injuries caused by a Naja atra.

We report a case of local antivenom therapy for ocular exposure to the venom of Naja atra. An 83-year-old woman sustained conjunctival and corneal injuries by the venom of a spitting N. atra. Local instillation of N. naja antivenom quickly relieved the pain as measured by visual analog scale, and she recovered uneventfully. Good recovery ensuing topical antivenom administration for ocular exposure to the venom of spitting N. atra and Naja nigricollis has been described in literature, but the pain response was not thoroughly documented. The mechanism of antivenom for pain relief remains to be established. In light of the associated positive outcome observed in human, the role of ocular antivenom therapy merits further study.

Resequencing microarray for detection of human adenoviruses in patients with conjunctivitis.

BACKGROUND: Although high-density resequencing microarray is useful for detection and tracking the evolution of viruses associated with respiratory tract infections, no report on using this technology for the detection of viruses in patients with conjunctivitis is available. OBJECTIVES: To test if high-density resequencing microarray can be applied to detection of viruses in conjunctival swabs for patients with conjunctivitis. STUDY DESIGN: In this prospective proof-of-concept study, every 4 or 5 bacterial culture-negative conjunctival swab samples were pooled and subject to viral detection using TessArray Resequencing Pathogen Microarrays-Flu 3.1 (RPM-Flu-3.1). Results were compared with human adenovirus (HAdV) hexon gene PCR sequencing and viral culture. RESULTS: Thirty-two of the 38 conjunctival swab samples were bacterial culture-negative. Four of the 7 pooled samples were positive for HAdV using RPM-Flu-3.1. Hexon gene PCR sequencing on the 38 original individual samples showed that 3 and 4 samples contained HAdVs species D and B respectively. All the 6 samples that were positive for hexon gene PCR but negative for bacterial culture were also positive by the resequencing microarray. Viral culture was positive for HAdV type 3 in 1 sample, which was also positive by PCR and resequencing microarray. CONCLUSIONS: Resequencing microarray is as sensitive as PCR for detection of HAdV in conjunctival swabs. Unlike viral culture and hexon gene PCR sequencing, resequencing microarray was not able to differentiate the type and species of HAdV. Development of microarrays for conjunctivitis can be performed for rapid diagnosis of the viral cause of conjunctivitis.

Hemolytic anemia after zopiclone overdose.

INTRODUCTION: Zopiclone is associated with methemoglobinemia. We report a case of zopiclone overdose manifested with another hematological complication, hemolysis. CASE: A 46-year-old woman overdosed with 50-100 tablets of 7.5 mg zopiclone. Oxidative hemolysis was evident by anemia, bite cells, raised unconjugated bilirubin and lactate dehydrogenase, lowered haptoglobin, and reticulocytosis. DISCUSSION: In zopiclone overdose, there may be oxidative stress rendering the development of not only methemoglobinemia but also hemolysis.

Two cases of methemoglobinemia following zopiclone ingestion.

INTRODUCTION: Most cases of methemoglobinemia result from exposure to certain medications and chemicals such as nitrates, nitrites, aniline, dapsone, phenazopyridine, benzocaine, and chlorates which oxidize the iron from the ferrous state. Intoxication with zopiclone is expected to produce drowsiness, confusion and coma but not methemoglobinemia. We report two cases of zopiclone overdose with methemoglobinemia. CASE REPORTS: Case one: A 43-year-old woman presented to the emergency department two hours after ingesting 100 tablets of 7.5 mg zopiclone. Her initial vital signs, physical examination, chest x-ray, and electrocardiogram were normal. Two hours post-ingestion her methemoglobin level was 9.8%; 14 hours post-arrival she showed cyanosis of the lips and extremities and dyspnea after walking. The blood sample 16 hours post-ingestion was dark brown in color and the methemoglobin was 23.8%. Shortly after the second of two doses of methylene blue (1 mg/kg each) her methemoglobin was 3.6%. Case two: A 30-year-old woman came to the emergency department 50 hours after ingesting 150 to 200 tablets of 7.5 mg zopiclone. Her vital signs and physical examination were normal. Her methemoglobin level was 5.2% at 52 hours post-ingestion and it peaked at 10.4% one hour later. She recovered following symptomatic care. DISCUSSION AND CONCLUSIONS: Methemoglobinemia has not previously been reported following acute zopiclone overdose. In our patients, there were no identifiable alternative causes explaining the methemoglobinemia and zopiclone was confirmed in both patients by laboratory analysis. These two cases suggest that zopiclone overdose is capable of producing delayed methemoglobinemia, which may be related to formation of a sufficient quantity of the N-oxide metabolite.

Focused abdominal sonography for trauma in the emergency department for blunt abdominal trauma.

BACKGROUND: Blunt abdominal trauma (BAT) is a diagnostic challenge to the emergency physician (EP). The introduction of bedside ultrasound provides another diagnostic tool for the EP to detect intra-abdominal injuries. AIMS: To evaluate the performance of EP in a local emergency department in Hong Kong to perform the 'focused abdominal sonography for trauma' (FAST) in BAT patients. METHODS: This was a retrospective cohort study including all the trauma team cases in a 36-month period in the emergency department of a public hospital in Hong Kong. The results of FAST scans were analyzed and compared with CT scans when the FAST was positive or followed by a period of clinical observation when the FAST was negative. Descriptive statistics and sensitivity, specificity, and predictive values were calculated. RESULTS: There was a total of 273 cases, and FAST scans were performed in 242 cases. The sensitivity and specificity were 86% and 99%, respectively. The negative predictive value was 0.98, while the positive predictive value was 0.94. The overall accuracy was 97%. CONCLUSIONS: The performance of the EP in using FAST scans in BAT patients was encouraging. The high specificity (99%), positive predictive value (0.98), and likelihood ratio for positive tests (86) make it a good 'rule in' tool for BAT patients. The high negative predictive value also makes the FAST scan a useful screening tool. However, ultrasound examination is operator dependent, and FAST scan has its own limitations. For negative FAST scan cases, we recommend a period of monitoring, serial FAST scans, or further investigations, such as CT scan or peritoneal lavage.

A case of accidental ingestion of ant bait containing fipronil.

A 77-year-old woman accidentally ingested a commercial ant bait containing fipronil without development of obvious toxicity, supporting the safety of this new insecticide as demonstrated in animal studies. However, concentrated agricultural products may be more toxic, and the potential for seizures should not be overlooked. The pharmacological action, mechanism of selective insect toxicity, and clinical effects of fipronil are discussed.

Lead poisoning after ingestion of home-made Chinese medicines.

A young woman presented with non-specific generalized musculoskeletal pain. Investigations revealed anaemia, raised reticulocyte count, basophilic stippling and erythroid hyperplasia of the bone marrow. Further history showed that she had been taking home-made Chinese medicines for acne for two months and the blood lead level confirmed the diagnosis of lead poisoning. The medications were stopped and her condition gradually improved. Incorporating the use of herbal medicines into the routine medical history is important in early identification of herbal poisoning.

A follow-up study of electromagnetic interference of cellular phones on electronic medical equipment in the emergency department.

OBJECTIVE: Considering the growing use of cellular phones and the fast appearance of new phone models, the electromagnetic interference of currently popular cellular phones on electronic medical equipment was tested. METHODS: Three Personal Communication System cellular phones were put at different distances from multiple electronic medical devices, the interference effect was observed and the electromagnetic field strength measured with a spectrum analyser. RESULTS: Only two small pieces of equipment, the CO2 airway adapter and the haemoglucostix meter were affected and then only when the phone was in very close proximity. CONCLUSION: Compared to the results of our study in 1997 testing Global System for Mobile Communication phones, the Personal Communication System phones generated less electromagnetic interference. However a much larger scaled study and an accurate international electromagnetic interference standard are recommended before any change in the current restrictive hospital policy on mobile phone usage could be recommended.