1.Dilemmas in management of brain tumours in pregnancy.
Pei Shi LEW ; Wei Ching TAN ; Wei Keat TAN ; Hak Koon TAN
Annals of the Academy of Medicine, Singapore 2010;39(1):64-65
Brain Neoplasms
;
radiotherapy
;
Cesarean Section
;
Craniotomy
;
Female
;
Glioblastoma
;
radiotherapy
;
surgery
;
Humans
;
Infant, Newborn
;
Male
;
Patient Care Team
;
Patient Participation
;
Pregnancy
;
Pregnancy Complications, Neoplastic
;
radiotherapy
;
surgery
;
Pregnancy Trimester, Second
;
Radiotherapy, Adjuvant
;
Young Adult
2.Plasma and urine amino acid profiles in a healthy adult population of Singapore.
Annals of the Academy of Medicine, Singapore 2006;35(7):468-475
INTRODUCTIONThe analysis of amino acids in plasma and urine was introduced in Singapore when a laboratory for the investigation of inherited metabolic disorders was established by the Ministry of Health. Reference ranges are required for interpreting test results and making diagnoses. Initially, reference ranges established for Caucasians were used as there were no local data and we were unable to find data obtained by the same analytical method for Asian populations. This was not considered an ideal and long-term solution, as Singaporeans may have amino acid concentrations quite different from those of Caucasians due to genetic factors, dietary difference, environment, and other influences. This study was therefore undertaken when a number of healthy laboratory personnel volunteered to provide specimens for the study.
MATERIALS AND METHODSSixty healthy male and female laboratory workers not on any form of medication were recruited. They consisted of 24 males (range, 23 to 58 years) and 36 females (range, 20 to 60 years), with a mean age of 38.7 years. Non-fasting random blood and urine specimens were collected on ice. Removal of protein and peptides from heparinised plasma and urine was achieved by ultrafiltration through protein-exclusion membrane. Amino acid analysis on the ultrafiltrate was performed by a dedicated Beckman 6300 Amino Acid Analyzer using a cation exchange resin column and post-column colour reaction with ninhydrin reagent. Urine creatinine was measured by a Beckman LX 20 PRO Analyzer. Results for urine amino acids were expressed as micromol/mmol of creatinine.
RESULTSReference ranges for 32 amino acids in blood plasma and 36 amino acids in urine were calculated by a non-parametric method using the SPSS statistical calculation software. The ranges cover 95% of the population and the low and high limits of each reference range represent the 2.5th percentile and 97.5th percentile of the frequency distribution respectively.
CONCLUSIONSWe observed differences in the reference ranges of several plasma and urine amino acids between Singaporean and Caucasian populations. Moreover, the list of urine amino acids for Caucasian population is incomplete. We have therefore discontinued the use of reference values established for Caucasians and adopted the results of this study for our patient diagnostic work.
Adult ; Amino Acids ; analysis ; Asian Continental Ancestry Group ; European Continental Ancestry Group ; Female ; Humans ; Male ; Middle Aged ; Reference Values ; Singapore
3.Why we do caesars: a comparison of the trends in caesarean section delivery over a decade.
Candice P Y WANG ; Wei Ching TAN ; Devendra KANAGALINGAM ; Hak Koon TAN
Annals of the Academy of Medicine, Singapore 2013;42(8):408-412
INTRODUCTIONIn the United Kingdom, caesarean section (CS) rates have increased from 9% of deliveries in 1980 to 21% in 2001. A similar increase in CS rates has been seen in many developed countries. This is beyond the World Health Organisation's (WHO's) recommended level of 15%. This is a worrying trend as the risks of placenta previa, placenta accreta, hysterectomies, bladder and bowel injuries are increased with subsequent CS. We aim to ascertain the commonest indications for CS in a tertiary hospital and make recommendations to decrease future CS rates.
MATERIALS AND METHODSThis retrospective analysis compares the 5 most common indications for CS in 1999 and 2009. CS rates in the 2 study periods are tabulated and analysed as well.
RESULTSIn the first study period between January and December 1999, there were 2048 deliveries of which 365 were via CS. In the second study period of a decade later from January to December 2009, there were 1572 deliveries of which 531 were via CS. This gives an increase in CS rate from 17.8% in 1999 to 34% in 2009. The main indications for CS in 1999 were: cephalopelvic disproportion (18.6%), breech (14.2%), non-reassuring fetal status (11.8%), 1 previous CS (11.2%) and pregnancy-induced hypertension/pre-eclampsia/eclampsia (6.6%). The main indications for CS in 2009 were: 1 previous CS (18.1%), non-reassuring fetal status (12.2%), cephalopelvic disproportion (10.5%), 2 or more previous CS (7.9%) and breech (7.7%).
CONCLUSIONThere is a significant increase in CS rates over the last decade with an increased percentage of CS done because of a previous CS. This is associated with increased risk of complications as well. Recommendations are suggested with the view to decrease future CS rates.
Cesarean Section ; trends ; utilization ; Female ; Humans ; Pregnancy ; Retrospective Studies ; Time Factors
4.Challenges in the management of a rare case of extensive retroperitoneal haemangioma in a pregnant woman.
Shu-Qi TAN ; Jason Shau Khng LIM ; Yin Ru TAN ; Hak Koon TAN
Singapore medical journal 2014;55(11):e177-9
Haemangioma of the retroperitoneal space is a rare benign capillary malformation, which can grow significantly in pregnancy due to the multiple associated cardiovascular changes. We herein describe the case of a pregnant woman with an extensive right retroperitoneal haemangioma extending from the level of the renal hilum, across the lateral anterior abdominal wall and into the thigh. We also highlight the challenges faced in the management of the patient's delivery process. To the best of our knowledge, this is the first case of such nature and severity described in the English literature.
Adult
;
Cesarean Section
;
Female
;
Gestational Age
;
Hemangioma
;
diagnosis
;
surgery
;
Humans
;
Magnetic Resonance Imaging
;
Pregnancy
;
Pregnancy Complications, Neoplastic
;
Retroperitoneal Neoplasms
;
diagnosis
;
surgery
5.Safety and Efficacy of Chloral Hydrate Sedation in Paediatric Sedation for Ophthalmic Procedures.
Amy Mh CHAN ; Geok Koon TAN ; Huey Peng LOH ; Sock Huang LIM ; Audrey Wl CHIA
Annals of the Academy of Medicine, Singapore 2017;46(4):138-144
INTRODUCTIONChloral hydrate (CH) sedation is routinely used in paediatric ophthalmic examination in Singapore as an alternative to examination under general anaesthesia. Despite CH's traditionally high success rates and relatively low rate of adverse events, there is little data on its safety and efficacy as a sedative for ophthalmic procedures in an Asian population.
MATERIALS AND METHODSA retrospective chart review was performed, including children who underwent CH sedation at the Singapore National Eye Centre from January 2012 to January 2015. Participants were given an initial dose of CH and a top-up dose if required. Univariate and multivariate analyses were performed on data collected.
RESULTSCH sedation was successful in 144 of 153 children (94.1%). Of the 20 (13.0%) who required a top-up dose, 4 failed to sedate. The mean sedation onset was 29.4 minutes (SD: 24.3) and mean sedation duration was 56.5 minutes (SD: 24.0), with more than a third lasting more than 1 hour. The age of children, rather than initial dose of CH, was more relevant in determining success of sedation. Children who were >6 years old were 20.3 times more likely to fail sedation than those aged <2 years. During sedation, depression in the heart rate and a transient reduction of oxygen saturation was documented. All children recovered well post-sedation.
CONCLUSIONCH is a very useful sedative for paediatric ophthalmic procedures, especially in younger children. Children over 4 years old were more likely to fail sedation and require top-up doses. Alternative means of sedation may need to be considered in these cases.
6.Study of inherited metabolic disorders in Singapore - 13 years experience.
It-Koon TAN ; Bani GAJRA ; Maria S F LIM
Annals of the Academy of Medicine, Singapore 2006;35(11):804-813
INTRODUCTIONRecommended by the National Advisory Council of the Disabled, the Ministry of Health of Singapore supported a nationwide study of inherited metabolic disorders (IMDs). When the 5-year project ended, investigations were provided as a diagnostic service. This paper documents our 13-year experience.
MATERIALS AND METHODSPatients with symptoms suggestive of an IMD were referred. Investigations on heparinised blood and/or urine included amino acid analysis using a Beckman 6300 Amino Acid Analyser, organic acids analysis using a Hewlett- Packard gas chromatography and mass spectrometry, mucopolysaccharides quantitative assay and high-resolution electrophoresis, sugars by thin-layer chromatography.
RESULTSOf the 3656 patients studied from 1992 to 2005, IMDs were found in 127 (77 males; 50 females; age range, 1 day to 56 years). Their ethnic distribution was: 55.1% Chinese, 19.7% Malays, 11.0% Indians, 11.0% other races and 3.2% unknown. IMD diagnosed comprised 41 (32.3%) organic acidurias, 34 (26.8%) amino acidaemias/acidurias, 14 (11.0%) urea cycle defects, 15 (11.8%) mucopolysaccharidoses, 6 (4.7%) carbohydrate disorders and 17 (13.4%) others. Twenty-three (18.1%) cases were diagnosed during the neonatal period and 36 (28.3%) after the age of 13.
CONCLUSIONPositive detection rate was 3.5% and 48 IMDs were found. Significant proportion of cases had late-onset IMDs. Early identification of IMDs permits timely management, genetic counselling and prenatal diagnosis.
Adolescent ; Adult ; Amino Acids ; metabolism ; Biomarkers ; blood ; cerebrospinal fluid ; urine ; Carbohydrates ; blood ; Child ; Child, Preschool ; Chromatography, Gas ; Female ; Follow-Up Studies ; Glycosaminoglycans ; metabolism ; Humans ; Infant ; Infant, Newborn ; Male ; Mass Spectrometry ; Metabolism, Inborn Errors ; epidemiology ; metabolism ; Middle Aged ; Prevalence ; Prognosis ; Retrospective Studies ; Singapore ; epidemiology ; Urea ; metabolism
7.External proficiency testing programmes in laboratory diagnoses of inherited metabolic disorders.
It Koon TAN ; Bani GAJRA ; Maria S F LIM
Annals of the Academy of Medicine, Singapore 2006;35(10):688-693
INTRODUCTIONThis paper shows the importance and value of external proficiency testing programmes in monitoring and improving a laboratory's diagnostic skills. It reviews and documents the wide variety of inherited metabolic disorders (IMDs) encountered in the programmes organised by the Human Genetics Society of Australasia and the College of American Pathologists.
MATERIALS AND METHODSThe programmes used actual patient specimens to assess a laboratory's ability to provide diagnoses based on laboratory tests results and brief clinical information. Participating laboratory was also required to suggest additional test(s) to confirm diagnoses.
RESULTSThe results of diagnoses on 116 samples were reviewed. Altogether 49 IMDs were encountered, including 26 organic acidurias, 16 aminoacidurias, 3 urea cycle defects, 5 mucopolysaccharidoses, and 1 each of mucolipidosis and purine disorder. Our report for 21 of the 116 samples (18.1%) deviated from the actual diagnoses. Deviations from the final diagnoses were recorded along with the reasons for them. The main reasons for the deviations were: the lack of standards for recognising metabolites of pathognomonic significance, absence of characteristic metabolites in samples collected during treatment, the presence of misleading unusual metabolites, inadequate clinical information, and inability to perform additional tests due to insufficient specimens.
CONCLUSIONSThe programmes provided a wide variety of IMDs, some of which we have yet to encounter in our patients. They also enabled us to learn about the varied biochemical manifestations at different stages of disease and the identity of previously unidentified metabolites. They enhanced our knowledge and experience and improved our diagnostic skills.
Australia ; Humans ; Laboratories ; standards ; Metabolism, Inborn Errors ; diagnosis ; New Zealand ; Pathology, Clinical ; standards ; Professional Competence ; Program Evaluation ; Quality Assurance, Health Care ; Quality Control ; Specimen Handling ; standards
8.Lessons learnt from two women with morbidly adherent placentas and a review of literature.
Edwin W H THIA ; Lay-Kok TAN ; Kanagalingam DEVENDRA ; Tze-Tein YONG ; Hak-Koon TAN ; Tew-Hong HO
Annals of the Academy of Medicine, Singapore 2007;36(4):298-303
INTRODUCTIONPathologically adherent placentas occur when there is a defect of the decidua basalis, typically arising from previous caesarean section, resulting in abnormally invasive implantation of the placenta. The depth of placental invasion varies from the superficial (accreta), to transmural and possibly beyond (percreta).
CLINICAL PICTUREWe report on 2 cases, one treated "conservatively", the other with a caesarean hysterectomy, both of which led to a safe outcome for both mother and baby.
CONCLUSIONSManagement relies on accurate early diagnosis with appropriate perioperative multidisciplinary planning to anticipate and avoid massive obstetric haemorrhage at delivery.
Adult ; Cesarean Section ; adverse effects ; utilization ; Decidua ; abnormalities ; Female ; Humans ; Hysterectomy ; Incidence ; Magnetic Resonance Imaging ; Placenta ; abnormalities ; diagnostic imaging ; Placenta Accreta ; diagnosis ; epidemiology ; etiology ; physiopathology ; Pregnancy ; Thailand ; epidemiology ; Ultrasonography ; Uterine Hemorrhage ; etiology
9.First Feasibility Study and Short-term Outcomes of Laparoscopic-Assisted Anterior Resection in Colorectal Cancer in Malaysia
Henry Chor Lip TAN ; Jih Huei TAN ; Nur Akmalrudin NUR DZAINUDDIN ; Koon Khee CHAN
Annals of Coloproctology 2020;36(2):94-101
Purpose:
The purpose of this study was to demonstrate the feasibility and safety of laparoscopic-assisted anterior resection (LAAR) for colorectal cancer in a local Asian population.
Methods:
This is a retrospective review of all patients with colorectal cancer operated from November 2017 to October 2018. Main variables of interest were demography, type and surgery, length of stay (LOS), and the involvement of proximal and distal doughnut. Postoperative complications were analysed using chi-square or Fisher exact and Mann-Whitney tests.
Results:
There were 23 patients with a mean age of 62.5 ± 12.2 years. The mean time from diagnosis to surgery was 97.1 ± 154.84 days. There were 12 patients in the LAAR group and 11 in the open anterior resection (OAR) group. Duration of surgery was shorter in OAR (129.58 ± 51.38 minutes) compared to LAAR (147.91 ± 39.37 minutes). Mean LOS was shorter in the LAAR group with 5±1.5 days compared to the OAR group of 7.42 ± 4.25 days. However, there was no significant P-value for both duration of surgery (P = 0.322) or LOS (P = 0.87). A total of 3 complications were recorded after OAR and 2 after LAAR. Both groups had clear proximal and distal margins with 16 (12–18.5) harvested lymph nodes in LAAR and 18 (16–22) in OAR, which were equal (P = 0.155).
Conclusion
This study reports a shorter LOS in the minimally invasive group of 2 days with similar oncologic resection outcomes. This shows that LAAR is feasible in Malaysia and has potential outcome benefits.
10.Life threatening and occult mediastinal haemorrhage secondary to acquired factor VIII deficiency.
Chieh Suai TAN ; Kenneth P CHAN ; Charles T CHUAH ; Heng Joo NG ; Foong Koon CHEAH ; Felicia S TEO ; Philip C T ENG
Annals of the Academy of Medicine, Singapore 2009;38(3):280-281
Aged
;
Female
;
Hemophilia A
;
complications
;
Hemorrhage
;
etiology
;
Humans
;
Mediastinal Diseases
;
etiology