Original Article

A Ali, M Kurien, SS Mathews, J Mathew
Correspondence: Prof Mary Kurien, kurien_mary@hotmail.com

ABSTRACT
Introduction Complications of acute infective sinusitis are a therapeutic emergency. The purpose of this study was to determine the clinical presentation, microbiological pattern, treatment modalities and outcome of patients diagnosed to have acute rhinogenic orbital, intra- and extra-cranial complications from a developing country in Asia.
Methods A retrospective chart review from October 1999 to January 2004 was conducted.
Results Among 247 ENT surgical emergencies documented, 13 patients (5.3 percent) were diagnosed to have acute sinusitis with various complications either as in solitary or multiple forms. Orbital complications were the most common (61.5 percent) followed by acute subdural empyema (23.1 percent) and meningitis (15.2 percent). Subdural empyema was the most common intracranial complication. Staphylococcus was reported to be the most common offending organism (45.5 percent). Majority of the patients (84.6 percent) had surgical drainage of the affected sinuses, 38.5 percent being endoscopic drainage while external approach was done for those with coexisting osteomyelitis (30.8 percent). Two patients had combined approach, and one patient had post-operative facial paresis. There was no mortality in our series.
Conclusion Early detection, aggressive medical and prompt surgical treatment by multidisciplinary approach involving ophthalmological, neurosurgical and rhinological procedures, can successfully treat the complications with a significant reduction in the morbidity and no mortality.

Keywords: acute rhinosinusitis, infective rhinosinusitis, rhinosinusitis complications
Singapore Med J 2005; 46(10): 540-544

BYH Thong, KP Leong, HH Chng
Correspondence: Dr Bernard Thong Yu Hor, bernard_thong@ttsh.com.sg

ABSTRACT
Introduction To study the profile of patients with allergy to the venom of insect stings.
Methods 31 consecutive cases referred to our clinical immunology/allergy outpatient service from June 1, 1998 to June 30, 2002 were reviewed.
Results These patients comprised 3.5 percent of 889 cases referred during the study period. Their mean age was 28.8 +/- 10.5 (range 19-57) years and the majority were males (90.3 percent). Of these, 20 (64.5 percent) were Chinese, four (12.9 percent) were Malays and seven (22.6 percent) were of other races. 19 patients (61.3 percent) were men from the uniformed services including 12 (63.2 percent) full-time National Servicemen. 71 percent (22 patients) were stung for the first time. Urticaria (22 cases, 71.0 percent), dyspnoea (13, 41.9 percent), angioedema (12, 38.7 percent) and syncope (ten, 32.3 percent) were the most common manifestations of insect allergy. Anaphylaxis occurred in 22 (71.0 percent) cases, constituting 30.1 percent of all cases of anaphylaxis referred to our service during the study period. Although the causative insect was identified as honeybee (12, 38.7 percent), ant (four, 12.9 percent), wasp (three, 9.7 percent), and fire ant (two, 6.5 percent) by the majority of patients, ten (32.2 percent) patients were unable to identify the causative insect. The two patients stung by fire ants were Americans working in Singapore who had been stung while in the United States. Among those with anaphylaxis, honeybee, wasp and fire ant venom, for which specific immunotherapy is available, were identified as the cause in 40.9 percent, 4.5 percent, and 4.5 percent, respectively.
Conclusion Insect venom hypersensitivity made up 3.5 percent of allergy/immunology referrals and 32.8 percent of cases of anaphylaxis referred to our institution. The majority were military servicemen who developed allergic reactions during the course of duty. The inability to identify the causative insect in 50 percent with sting anaphylaxis limits the role of specific immunotherapy in our patients.

Keywords: anaphylaxis, insect venom, radioallergosorbent test, skin tests, specific immunotherapy
Singapore Med J 2005; 46(10): 535-539

BYH Thong, YK Cheng, KP Leong, CY Tang, HH Chng
Correspondence: Dr Bernard Thong Yu Hor, bernard_thong@ttsh.com.sg

ABSTRACT
Introduction To study the clinical features and causes of anaphylaxis in consecutive adult patients referred to a clinical immunology/allergy centre in Singapore.
Methods A retrospective review of 67 consecutive adults with anaphylaxis who presented from July 1, 1998 to February 28, 2002 was performed. Anaphylaxis was defined as a severe life-threatening systemic IgE-mediated hypersensitivity reaction. Non-steroidal anti-inflammatory drug-induced idiosyncratic reactions and other non-IgE mediated reactions were excluded. Hypotension and bronchospasm were not required to make a diagnosis. The aetiology was determined from clinical history followed by measurement of allergen-specific IgE levels, skin prick test with commercially-available allergen extracts or prick-prick test with the fresh/cooked/canned food products.
Results The mean age of patients was 32.9 +/- 10.9 (range 19-57) years. There were 44 (65.7 percent) males and 23 (34.3 percent) females. The main causes were food (44.8 percent), insect stings (32.8 percent) and idiopathic (22.4 percent). There were no cases due to drugs or natural rubber latex. Seafood (crustaceans and molluscs) comprised 66.7 percent of food-induced anaphylaxis. Honeybee and wasp stings together comprised 45 percent of insect venom anaphylaxis. The most common manifestations were dyspnoea (59.7 percent), urticaria (58.2 percent), angioedema (44.8 percent), and syncope (43.3 percent). Hypotension was documented in only 28.4 percent of cases.
Conclusion Food (crustaceans and molluscs) was the most common cause followed by insect stings or bites. The inability to identify the causative insect in 50 percent of cases with insect venom anaphylaxis limited the role of specific immunotherapy. Compared to other reported series, there were no cases of drug or latex anaphylaxis.

Keywords: hypersensitivity, radioallergosorbent test, skin tests, immunotherapy
Singapore Med J 2005; 46(10): 529-534

P Nyiri
Correspondence: Dr Polly Nyiri, pollybrandon@btinternet.com

ABSTRACT
Introduction The World Health Organisation has identified schools as key players in the global effort to reduce the rising incidence of skin cancer. Singapore lies 70 miles from the Equator, with one of the world's highest ultraviolet (UV) index scores. It is a multi-ethnic society, with many expatriates. Children in Singapore are likely to be exposed to high levels of UV radiation, and represent a variety of skin types. This study aimed to assess sun protection measures in schools, the frequency of reported sunburn in schoolchildren of different ethnic groups, the level of parental and school concern about sun exposure, the sun-protective measures currently in place, and the parental and school support for public education and "sunsmart" school programmes.
Methods Questionnaires were sent to principals and parents of primary schoolchildren in 20 local and eight international schools in January 2003.
Results The majority of children in all ethnic groups in Singapore were reported to suffer to some degree from sunburn during their first ten years. Over 50 percent of parents and head teachers predicted an increased risk of skin cancer in their children. Some protective measures were in place. But teachers and parents were concerned, and most favoured the promotion of more active measures.
Conclusion The reported incidence of sunburn among Singaporean school children is higher than expected across all ethnic groups. Given the current level of sun protective measures in place, more could be done to educate parents and schools regarding "sunsmart practice", and reducing their future risk of skin cancer and eye damage.

Keywords: cataract, melanoma, school children, skin cancer, sunburn
Singapore Med J 2005; 46(9): 471-475

CS Foo, KH Tay, T Ravintharan
Correspondence: Dr Chek Siang Foo, foo.chek.siang@singhealth.com.sg

ABSTRACT
Introduction Laparoscopic adjustable gastric banding (LAGB) has been used for the treatment of obesity, being shown in western populations to be a safe and effective option. We present the results of our experience in the use of LAGB in the treatment of obesity.
Methods A retrospective review of all patients who underwent LAGB from February 1999 to June 2004 was made from a prospectively collected database. Pre-operative comorbidities, height, weight and body mass index (BMI) were recorded and compared with post-operative results. Operative times, length of stay and complications were also noted.
Results 38 consecutive patients underwent LAGB. The 16 male and 22 female patients had a mean age of 37.6 years (range 19 to 62 years) and a mean BMI of 42.7 kg per square metre (range 28.8 to 78.4 kg per square metre). Nine were done utilising the perigastric approach, and the other 29 with the pars flaccida approach. There were no open conversions. Overall peri-operative morbidity was encountered in two (5.3 percent) patients, with a minor liver laceration and a capsular splenic laceration in separate patients. There were no post-operative complications. One (2.7 percent) patient had the band removed at 29 months post-operatively on request. There were no mortalities. Mean follow-up period was 13 months (range one to 56 months). Mean BMI decreased to 40.7, 38.7, 37.4, 34.1 and 32.9 kg per square metre, respectively, at one week, one, six, 12 and 18 months post-operatively.
Conclusion LAGB is a feasible modality in the multifaceted approach to treatment of morbid obesity. The results from our follow-up are comparable to larger series in western populations, with a similar safety profile.

Keywords: bariatric surgery, gastric banding, laparoscopic adjustable gastric banding, laparoscopic surgery, obesity
Singapore Med J 2005; 46(9): 465-470

S Misbah, H Hassan, MY Yusof, YA Hanifah, S AbuBakar
Correspondence: Prof Sazaly AbuBakar, sazaly@um.edu.my; sazaly@ummc.edu.my

ABSTRACT
Introduction This study aims to identify Acinetobacter of clinical isolates from the University of Malaya Medical Centre (UMMC), Kuala Lumpur, to the species level by 16S rDNA sequencing.
Methods 12 representative Acinetobacter isolates of the UMMC inpatients were randomly picked and used for the study. The 16S rDNA sequences were determined and phylogenetic relationships to all known Acinetobacter species were established.
Results Based on the 16S rDNA sequences, all the UMMC isolates were identified as Acinetobacter baumannii. The isolates shared a common ancestral lineage with the prototypes Acinetobacter baumannii DSM30007 and DSM30008 with 99-100 percent sequence similarities. The isolates could be differentiated into two groups by a single nucleotide difference (thymine-cytosine) within the 16S rRNA sequence. Three different genotypes, 1, 3 and 4, were recognised using REP-PCR.
Conclusion The previously uncharacterised Acinetobacter isolates from the UMMC were identified by their 16S rDNA sequences as Acinetobacter baumannii. The isolates were distinguished into at least three different genotypes by REP-PCR genotyping. These findings confirmed for the first time the presence of Acinetobacter baumannii of different genotypes among patients at UMMC.

Keywords: Acinetobacter, genomic species identification, genotyping, 16S ribosomal RNA
Singapore Med J 2005; 46(9): 461-464

ZE Astal
Correspondence: Dr Zakaria El Astal, zalastal@yahoo.com

ABSTRACT
Introduction This study aims to assess common organisms causing urinary tract infection (UTI) in the Gaza Strip, Palestinian Authority and to examine the incidence of ciprofloxacin resistance in the strains of bacteria isolated from patients suspected with UTI over a six-month period.
Methods Ciprofloxacin was evaluated along with other commonly-used antibiotics against a total of 480 clinical isolates obtained from urine samples. The samples were collected from community patients from different parts of the Gaza Strip. Susceptibility tests were done by the Kerby Bauer method.
Results Among the tested drugs, the percent resistance rate to ciprofloxacin was 15.0 percent. However, high resistance to ciprofloxacin was detected among Acinetobacter haemolyticus (28.6 percent), Staphylococcus saprophyticus (25.0 percent), Pseudomonas aeruginosa (20.0 percent), Klebsiella pneumonia (17.6 percent) and Escherichia coli (12.0 percent). Minimal inhibitory concentration of ciprofloxacin was measured for all resistant UTI isolates.
Conclusion This study indicates emerging ciprofloxacin resistance among most UTI bacterial pathogens. Increasing resistance against ciprofloxacin demands coordinated monitoring of its activity and rational use of the antibiotics.

Keywords: antibiotic resistance, ciprofloxacin, urinary tract infection
Singapore Med J 2005; 46(9): 457-460

WJ Chng, C Sum, P Kuperan
Correspondence: Dr Chng Wee Joo, chngwj@nuh.com.sg

ABSTRACT
Introduction To determine the causes of isolated prolonged activated partial thromboplastin time (APTT) in an acute care general hospital setting so as to rationalise fresh frozen plasma usage.
Methods A prospective study of consecutive patients with isolated prolonged APTT presenting to our hospital between February 2002 and January 2004 was performed. All patients had normal prothrombin time and thrombin time. For all patients, an initial 50:50 correction with plasma was done and a standard panel of tests was performed. These included detection of lupus anticoagulant using two different sensitive tests; measurement of coagulant factors VIII (FVIII), IX, XI and XII, which are involved in the intrinsic arm of haemostasis; von Willebrand factor antigen (vWF:Ag) levels and for those with FVIII levels less than 10 percent, an inhibitor assay using the Nijmegen modification of the Bethesda method.
Results 177 patients were included in the study. The cohort was typical of an acute care general hospital patient population in Singapore in terms of age, sex and racial distribution. The most common cause of an isolated prolonged APTT in our study was the presence of lupus anticoagulant (53.1 percent of cases). In 31.6 percent of cases, obvious cause could be detected after our panel of tests. These patients mostly had mildly prolonged APTT that could be both correctable and non-correctable by normal plasma. Prolonged APTT due to factor deficiency was relatively rare with those that may potentially cause haemorrhagic problems only accounting for 4.5 percent of cases.
Conclusion Our study suggests that most of the causes of isolated prolonged APTT do not lead to haemorrhagic complications. In fact, in a majority, it may signify an underlying thrombophilic condition. As a result, prolongation of APTT should be fully investigated and correction with fresh frozen plasma should be used only when appropriate.

Keywords: coagulation factors, fresh frozen plasma, lupus anticoagulant, prolonged activated partial thromboplastin time
Singapore Med J 2005; 46(9): 450-456

HK Goh, KY Tham, E Seow
Correspondence: Dr Hsin-Kai Goh, hsin_kai_goh@ttsh.com.sg

ABSTRACT
Introduction On March 13, 2003, Singapore doctors were alerted about an outbreak of atypical pneumonia that became known as severe acute respiratory syndrome (SARS). We now describe a series of patients that did not fit World Health Organisation (WHO) case definitions for SARS at initial assessment.
Methods The Ministry of Health, Singapore centralised SARS cases in the study hospital and its emergency department (ED) became the national screening centre. A screening questionnaire and a set of admission criteria based on WHO case definitions were applied. Patients discharged from ED were tracked via telephone surveillance and recalled if necessary. A retrospective review was done of patients who did not fit WHO definitions initially, were discharged and had re-attended.
Results During the outbreak, 11,461 people were screened for SARS. Among 10,075 (87.9 percent) discharged from the ED, there were 28 re-attendees diagnosed to have SARS later, giving an undertriage rate of 0.3 percent. Among the 28, six (21.4 percent) did not complain of fever and 22 (78.6 percent) had temperatures less than 38.0 degrees Celsius during their first ED visit. One patient was screened to have all three criteria but during consultation, the contact history was found to be unrelated to the known "hot spots". The initial mean temperature was 37.6 degrees Celsius (standard deviation [SD] 0.8), which increased significantly (p-value equals 0.04) to 38.0 degrees Celsius (SD 0.8) during their subsequent visit. Chest radiographs with infective changes increased significantly (p-value equals 0.009) from 16 percent to 52.4 percent over the two ED visits.
Conclusion The WHO case definitions were helpful in evaluating majority of SARS patients initially. However under-triage at ED is inevitable, with a 0.3 percent under-triage in our study population. In this group and asymptomatic individuals who came for screening, a tracking and recall system helped to ensure their timely return to the ED.

Keywords: atypical pneumonia, chest radiographs, emergency department, severe acute respiratory syndrome (SARS), World Health Organisation
Singapore Med J 2005; 46(8): 414-420

KK Poh, HC Tan, JWL Yip, YT Lim
Correspondence: Dr Poh Kian Keong, doctorpoh@yahoo.com

ABSTRACT
Introduction The pattern of use of abciximab in real-life clinical patients undergoing percutaneous coronary intervention (PCI) in 11 high-volume centres in Singapore, Malaysia, Thailand, Philippines, India, Pakistan and Korea was prospectively examined.
Methods These centres enrolled 224 consecutive patients over eight months to receive abciximab during PCI for the study. The cohort consisted of 82.1 percent males, with mean age of 55 (+/- 11) years and mean weight of 67 (+/- 17) kg.
Results The use of abciximab during PCI ranged between 6.2 percent and 21.6 percent. The indications for the use of abciximab were: acute coronary syndromes (34.3 percent), complex coronary lesions (17.9 percent) and multivessel PCI (17.7 percent). Based on a risk scoring system devised for this registry, majority (60.0 percent) of the patients was considered high risk when abciximab was used. Among the patients enrolled, 36.6 percent received abciximab as a "bail-out". The overall in-hospital ischaemic event rates were low at 4.0 percent. The complication rates included major bleeding 0.7 percent, thrombocytopenia 2.7 percent and need for blood transfusion 2.8 percent. There was a trend towards a higher incidence of in-hospital non-Q myocardial infarction in the "bail-out" group (2.1 percent versus 7.3 percent, p-value equals 0.07).
Conclusion Abxicimab was uncommonly used among patients (9.4 percent) undergoing PCI in this Asian region, with the operators reserving it mainly for high-risk patients.

Keywords: abciximab, adjuvant drug therapy, angioplasty, coronary disease, percutaneous coronary intervention
Singapore Med J 2005; 46(8): 407-413