Biomedical subjects

H M Tan

Publications and source records attributed to H M Tan.

At least 19 recordsLinked to original sources

PubMed2006

Ultra-low dose combined spinal-epidural anesthesia with intrathecal bupivacaine 3.75 mg for cesarean delivery: a randomized controlled trial.

BACKGROUND: We wished to investigate the feasibility of an ultra low-dose combined spinal-epidural technique in providing surgical anesthesia for uncomplicated cesarean deliveries in a randomized, double-blind controlled trial. METHOD: Forty-four normotensive, non-obese patients were randomized to receive either intrathecal hyperbaric bupivacaine 3.75 mg (low dose group, n=22) or 9 mg (conventional group, n=22), in addition to intrathecal fentanyl 25 microg, morphine 100 microg, and epidural 1.5% lidocaine 3 mL. Sensorimotor anesthesia and hemodynamic data were assessed at 2.5-min intervals for the first 15 min. RESULTS: The maximal sensory block achieved in the low-dose group was significantly lower than that in the conventional group (median T3, [range T2-T6] vs. T2 [C2-T6], P<0.001) with a longer time taken to reach maximal sensory block. The low-dose group had less motor block, faster sensory regression to T10 dermatome and faster motor recovery to Bromage 0 (all P<0.001). The block failed to reach T6 bilaterally within 10 min in one patient in the low-dose group and two in the conventional group, with no significant difference in the need for epidural supplementation before or after delivery of the baby. The low-dose group experienced less hypotension (14% vs. 73%, P<0.001) with less ephedrine usage (0.68 vs. 17.5 mg, P<0.001). There was no difference in operating conditions and other side effects (shivering, pruritus). CONCLUSION: We conclude that this technique results in a significantly lower incidence of maternal hypotension and has a role in high-risk parturients in whom maintenance of stable hemodynamics is imperative.

Adult↗

PubMed2005

Facial palsy from temporal bone lesions.

INTRODUCTION: Facial nerve palsy results in the loss of facial expression and is most commonly caused by a benign self-limiting inflammatory condition, known as Bell's palsy. However, there are other conditions which may result in injury of the seventh cranial nerve and the radiologist should be familiar with their imaging appearances. MATERIALS AND METHODS: The relevant anatomy of the facial nerve and pathology which may affect the intratemporal portion of the nerve is described. The role of imaging and choice of imaging modality is also reviewed. RESULTS: High-resolution computer tomography(HRCT) images of the temporal bone and magnetic resonance(MR) images of the facial nerve from 11 patients who presented with facial nerve palsy were used to illustrate how intratemporal facial nerve injury of other aetiologies can mimic Bell's palsy. The typical imaging appearance of Bell's palsy was also presented. CONCLUSIONS: Most patients with suspected Bell's palsy do not require radiologic imaging. However, when symptoms progress, persist or when there is multiple cranial nerve involvement, recurrent symptoms or subacute onset of facial nerve palsy, causes other than Bell's palsy should be considered.

Cranial Nerve Neoplasms↗

PubMed2005

Analgesic efficacy of pre-operative etoricoxib for termination of pregnancy in an ambulatory centre.

INTRODUCTION: Etoricoxib is a second generation cyclooxygenase-2 inhibitor with a rapid-onset time and a long duration of action. It is ideal for providing pre-emptive analgesia for ambulatory surgeries. We hypothesised that pre-operative etoricoxib can decrease the use of fentanyl post-operatively, when compared with placebo in patients undergoing termination of pregnancy. We also compared their pain scores, time to discharge, side effects and satisfaction with analgesia post-operatively. METHODS: After approval by the hospital research ethics committee and receipt of informed written consent, we recruited 40 American Society of Anesthesiologists Physical Status Classification I and II patients scheduled for elective first trimester termination of pregnancy. Patients were randomly allocated to receive either oral etoricoxib 120 mg (Group E, n=20) or placebo tablet (Group P, n=20) pre-operatively. A blinded observer evaluated the post-operative pain scores, need for supplementary analgesia, side effects and satisfaction scores. Sample size was calculated (power of 0.8 and alpha=0.05) to detect a 20 percent difference in fentanyl usage. Amount of fentanyl used, pain scores and satisfaction scores were analysed using non-parametric tests. The incidence of side effects was analysed using chi-squared test. RESULTS: Etoricoxib 120 mg significantly decreased the amount of fentanyl required after termination of pregnancy compared to placebo (0 microg/patient, interquartile range [IQR] 0-25 versus 50 microg/patient, IQR 0-50, p-value is less than 0.05). Patients who received etoricoxib 120 mg also had significantly lower pain scores than the placebo group at time of discharge (8 +/- 11 versus 1 +/- 3, p-value is less than 0.05) and at six hours post operation (8 +/- 12 versus 0 +/- 0, p-value is less than 0.01). There was no difference in their side effects, and time to discharge and overall satisfaction were similar in both groups. CONCLUSION: Pre-operative administration of oral etoricoxib 120 mg decreased the use of fentanyl and pain scores after minor gynaecological surgery without significant side effects.

Abortion, Induced↗

PubMed2005

Migration of a foreign body in the maxillary sinus illustrating natural mucociliary action.

We present a case of a foreign body which migrated to the maxillary ostia by mucociliary action from its initial location on the floor of the maxillary sinus where it was traumatically introduced. This report illustrates that a powerful mechanism of mucociliary action can cause relatively heavy objects within the maxillary sinus to migrate naturally to the sinus ostia against gravitational force.

Adult↗

PubMed2005

Evaluation of surgical and anaesthesia response times for crash caesarean sections--an audit of a Singapore hospital.

INTRODUCTION: The Royal College of Obstetricians and Gynaecologists published the "Organisational Standards for Maternity Services" in 1995, in which they proposed that there be a maximum decision-to-delivery time of 30 minutes for urgent caesarean sections (CS). In 1997, our institution established a protocol for extremely urgent ("crash") CS to expedite delivery time and to conform to this standard. MATERIALS AND METHODS: The objective of this prospective audit was to determine the surgical and anaesthesia response times in our institution after the protocol had been implemented. The audit was conducted in KK Women's and Children's Hospital from February 2003 to January 2004, over a 12-month period. Upon activation of a "crash" CS, the attending anaesthetist was required to record the decision-to-anaesthesia time, decision-to-delivery time and the perinatal outcome. RESULTS: Ninety-eight cases of "crash" CS were identified from a total of 3629 elective and non-elective CS, with 80 cases having complete data. The mean decision-to-delivery interval was 7.7 min+/-3.0 (SD) with 100% of deliveries made within 17 minutes. The mean decision-to-anaesthesia time was 3.5 min+/-2.0 (SD) with all the patients anaesthetised within 10 minutes. The majority (88.8%) of the patients had general anaesthesia for "crash" CS while the rest had successful epidural block extension. There was no significant difference in the decision-to-delivery interval or mean cord blood pH with respect to the type of anaesthesia given. CONCLUSIONS: We achieved 100% deliveries within the proposed 30-minute decision-to-delivery time interval by implementing a protocol for "crash" CS. Both general anaesthesia and extension of existing epidural block are acceptable modes of anaesthesia and do not delay delivery of the fetus.

Anesthesia, Obstetrical↗

PubMed2005

Migration of a foreign body in the maxillary sinus illustrating natural mucociliary action.

Adult↗

PubMed2004

Monophasic, solitary tumefactive demyelinating lesion: neuroimaging features and neuropathological diagnosis.

The characteristic clinicoradiological findings of multiple sclerosis and acute disseminated encephalomyelitis (ADEM), demonstrating a recurrent progressive course in the former and monophasicity in the latter associated with multiple discrete white matter lesions with variable enhancement on MRI, are not a diagnostic challenge. On the other hand, the less typical radiological presentation of a solitary tumefactive demyelinating lesion mimics a neoplasm, and often necessitates a biopsy. Nonetheless, histopathological examination is an imperfect gold standard and the recognition of certain imaging features may facilitate the correct diagnosis.

Adult↗

PubMed2004

Audit of diagnostic and interventional craniocervical catheter angiographic procedures at the Singapore General Hospital.

INTRODUCTION: Catheter angiography is an established imaging modality of evaluating cerebral and head and neck vascular diseases. It is, however, an invasive procedure with a small risk of complications. The aim of our study was to evaluate the prevalence of peri-procedural complications in a local hospital setting. MATERIALS AND METHODS: A total of 88 patients underwent diagnostic and interventional craniocervical procedures over 6 months in our department. The casenotes of 83 patients were retrospectively reviewed for complications arising from a total of 99 procedures carried out. RESULTS: A new focal neurological deficit developed in 3 different patients after a procedure, giving a prevalence of 3.0%. All these occurred in diagnostic procedures and were permanent deficits with correlative computed tomography (CT) or magnetic resonance (MR) imaging findings of acute cerebral infarction. All these occurred in high-risk patients who had severe underlying cerebrocarotid vascular compromise. There was 1 case of contrast medium-induced nephropathy (1.0%), occurring in a patient with pre-existing renal impairment. Local complications included 1 case of iatrogenic external iliac artery dissection (1.0%) and 5 cases (5.1%) of small and uncomplicated puncture site groin haematomas. CONCLUSION: The most significant complication associated with a craniocervical angiographic procedure was the development of post-procedural stroke in patients with significant preexisting cerebrocarotid vascular compromise. In the absence of this risk factor, craniocervical catheter angiography is a relatively safe procedure.

Adolescent↗

PubMed2004

[Comparison of preemptive analgesia efficacy between etoricoxib and rofecoxib in ambulatory gynecological surgery].

OBJECTIVE: To compare the preemptive analgesia efficacy between two cycloxygenase-2 inhibitors, rofecoxib and etoricoxib in the ambulatory uterine evacuation patients. METHODS: In this randomized, double-blinded, placebo-controlled trial 60 patients were randomly divided into three groups and received a single dose of placebo, rofecoxib 50 mg, or etoricoxib 120 mg, respectively, before operation. Patient's visual analogue score (VAS) was rated postoperatively at 15 min, 30 min, 60 min, time-to-discharge, 6 h and 24 h. Fentanyl (in post-anesthesia care unit) and paracetamol (at home) were supplementary analgesics and the dosage was also recorded. Patient's satisfaction score was rated at 24 h postoperatively. RESULTS: Etoricoxib 120 mg and rofecoxib 50 mg were significantly superior to placebo at 6 h postoperatively (P < 0.05) while there was no significant differences of VAS at other time points. The amounts of Fentanyl used in post-anesthesia care unit were similar in three groups, but paracetamol taken at home was much less in rofecoxib group and etoricoxib group than in placebo group (P < 0.01). Compared to rofecoxib, etoricoxib provided better pain relief after discharge (P < 0.05). The overall pain management satisfaction score was significantly higher in etoricoxib group (96 +/- 7) than in other groups (P < 0.01). CONCLUSION: Preemptive rofecoxib 50 mg and etoricoxib 120 mg may significantly decrease VAS at 6 h postoperatively, and reduce the usage of analgesics in ambulatory uterine evacuation patients. Etoricoxib 120 mg offeres better pain relief at home compared with rofecoxib 50 mg.

Abortion, Induced↗

PubMed2003

Pancreatitis leading to retroperitoneal fibrosis and ureteric obstruction.

Two patients who had acute pancreatitis subsequently developed characteristic appearance on urography of smooth extrinsic narrowing and medial deviation of the right ureter suggestive of retroperitoneal fibrosis (RPF) resulting in ureteric obstruction. Both these patients had clinical, biochemical and sonographic evidence of acute pancreatitis. CT scan of the abdomen performed on the second patient also documented acute pancreatitis. Intravenous urograms were consistent with ureteric obstruction due to retroperitoneal fibrosis. Both cases were treated conservatively. They were well after an average of 20 months. These 2 cases illustrate the uncommon association between pancreatitis and RPF.

Acute Disease↗

PubMed2003

Neuraxial block for labour analgesia--is the combined spinal epidural (CSE) modality a good alternative to conventional epidural analgesia?

AIM: Apart from conventional epidural analgesia (EA), the combined spinal-epidural (CSE) modality is fast becoming a popular technique for treating labour pain. In this study, we investigated the differences in the patient profile and outcome between CSE and EA for labour pain in KK Women's and Children's Hospital. METHODOLOGY: Data pertaining to 1,532 healthy parturients who had received either CSE or EA for labour pain during a six-month period was systematically collected by using a specially designed form. Multiple logistic regression analysis was used to determine the independent predictors of patient satisfaction and the relation of parturient factors on the choice of block. The side effects and the outcome of labour were also compared. RESULTS: CSE accounted for 80% of all neuraxial blocks performed for labour analgesia (vs 20% for EA). Anaesthesiologists were more inclined to using CSE than EA for multiparous parturients (OR 2.03, p<0.01) in a more painful (OR=1.61, p=0.03) and advanced stage of labour (OR=1.12, p=0.03). The need for supplemental analgesics was greater for EA (p<0.01). Patient satisfaction was higher for CSE (OR=1.77, p<0.026). CSE had a higher risk of pruritus (29% vs 14%, p<0.01) but lower risk of post block neural deficits (0% vs 2%, p<0.01) than EA. No difference in the mode of delivery was detected between the two groups. CONCLUSION: CSE is a safe and good alternative to EA as a technique of neuraxial block for labour analgesia.

Analgesia, Epidural↗

PubMed2002

Malaysian cultural differences in knowledge, attitudes and practices related to erectile dysfunction: focus group discussions.

This qualitative study aimed to examine cultural differences in knowledge, attitudes and practices related to erectile dysfunction (ED) utilizing focus group discussion. Six focus groups consisting of 66 men, 45-70-y-old were conducted-two Malay groups (n=18), two Chinese groups (n=25) and two Indian groups (n=23). Participants were purposely recruited from the general public on a voluntary basis with informed consent. Transcripts were analyzed using qualitative data analysis software ATLASti. The Malay and Chinese traditional remedies for preventing or treating ED are commonly recognized among all races. Many have a negative perception of someone with ED. Malay and Chinese men tended to blame their wife for their problem and thought that the problem might lead to extra-marital affairs, unlike the Indian men who attributed their condition to fate. Malays would prefer traditional medicine for the problem. The Chinese felt they would be more comfortable with a male doctor whilst this is not so with the Malays or Indians. Almost all prefer the doctor to initiate discussion on sexual issues related to their medical condition. There is a need for doctors to consider cultural perspectives in a multicultural society as a lack of understanding of this often contributes to an inadequate consultation.

Aged↗

PubMed2002

What Malaysian women believe about Viagra: a qualitative inquiry.

This paper highlights women's perceptions of sildenafil citrate (Viagra, Pfizer). It is based on a qualitative study on perceptions of erectile dysfunction in the Malaysian multicultural society. Six focus groups were conducted, consisting of 69 women, aged between 40 and 70 years, recruited from the general public and who had given informed consent. The findings revealed that the women were aware of erectile dysfunction and Viagra. Due to their concern about the negative aspects of Viagra, the Chinese and Malay traditional methods of treatment were commonly mentioned. The women from three ethnic groups viewed the possibility of their husband starting to take Viagra with lots of suspicion, mistrust and fear. They would prefer their husband discussing with them the issue of resorting to taking Viagra. The Chinese and Indian women perceived that if a man takes Viagra, it will boost his ego and he will feel more manly. Indian women felt that a man taking Viagra is proof of his love for his wife. The Malay women felt that a man would be ashamed and have a low self-esteem if he were to resort to taking Viagra. Although Viagra is meant for the male, understanding of women's perception of it is beneficial for a couple's sexual relationship.

Adult↗

PubMed2001

Either sufentanil or fentanyl, in addition to intrathecal bupivacaine, provide satisfactory early labour analgesia.

PURPOSE: The study was aimed primarily at comparing the duration of analgesia produced by intrathecal fentanyl 25 microg with sufentanil 5 microg when added to bupivacaine 1.25 mg as the initial component of the combined spinal epidural (CSE) technique in early labour. METHODS: Forty healthy parturients were randomly assigned into two groups to receive either intrathecal sufentanil 5 microg plus bupivacaine 1.25 mg (Group S) or intrathecal fentanyl 25 microg plus bupivacaine 1.25 mg (Group F). Apart from the duration of analgesia, pain scores and side effects were also evaluated. RESULTS: There was no significant difference in the duration of analgesia (mean 109 +/- SD 49 min in Group F vs 118 +/- 54 min in Group S, P=0.9). Group F had a more rapid onset of analgesia (P <0.05) and a higher cephalad block (median T4 vs T7, P <0.05) in the first 30 min after the block. No difference in the side effects was detected. CONCLUSION: Fentanyl 25 microg is a good alternative to sufentanil 5 microg when added to bupivacaine 1.25 mg for early labour analgesia.

Adult↗

PubMed2001

Comparison of sevoflurane-nitrous oxide anaesthesia with the conventional intravenous-inhalational technique using bispectral index monitoring.

Ninety-one patients were randomly allocated to one of two groups. Group A was induced with a single vital capacity breath of 6% (end-tidal) sevoflurane in nitrous oxide-oxygen (2 : 1 l.min-1), whereas group B was induced with intravenous fentanyl 1 microg.kg-1 + propofol 2 mg.kg-1 followed by nitrous oxide-oxygen (2 : 1 l.min-1) and sevoflurane. Induction was considered to have been achieved when the bispectral index value decreased to below 70. Mean induction time in group A (95.2 s, 95% CI 88.5-101.9 s) was longer than group B (70.3 s, 95% CI 66.3-74.3 s; p < 0.0001). Mild coughing was more common in group A, but relative hypotension was more common in group B. There was no difference in the emergence times. Thirty minutes after emergence, there was no difference in the incidence of adverse effects, with the exception of essentially mild abdominal pain which was more frequent in group A.

Adult↗

PubMed2001

A distinctive shoulder mass.

Explore the source record for details and available documents.

Humans↗

PubMed2001

Obstetric admissions to the intensive therapy unit of a tertiary care institution.

INTRODUCTION: Between 0.1% and 0.9% of women develop pregnancy complications which require admission to an intensive therapy unit. The aim of this study was to review all obstetric admissions to the intensive therapy unit at the KK Women's and Children's Hospital from 1998 to 1999 with respect to indications for admission, interventions employed and clinical outcome. METHOD: The medical records of all obstetric patients admitted to the intensive therapy unit during the 2-year period were analysed retrospectively. Subjects were included if they were admitted during pregnancy up to 42 days postpartum. RESULTS: There were 31,725 deliveries in our hospital during the study period of which there were 239 admissions to the intensive therapy unit. Of these, 42% were Malays, 41% Chinese, 12% Indians and 5% other races. 65% stayed 1 day, 24% 2 days, 7% 3 days and 4% more than 3 days. The patients' ages ranged from 18 to 44 years. The indications for admission were hypertension (50%), haemorrhage (24%), respiratory insufficiency (10%), neurological problems (11%) and sepsis (3%). Intervention-wise, 43% of patients required vasoactive infusions, 35% had arterial line placement, 22% central venous pressure monitoring, 21% ventilatory support and 2% pulmonary artery catheter placement. The maternal mortality and stillbirth rates were 1.3% and 3.7% of intensive therapy unit admissions, respectively. CONCLUSION: The admission rate to the intensive therapy unit in our institution was 0.73% of all deliveries during the 2-year study period. Hypertensive disease and haemorrhage were the predominant admitting diagnoses.

Adolescent↗

PubMed2000

Asian sildenafil efficacy and safety study (ASSESS-1): a double-blind, placebo-controlled, flexible-dose study of oral sildenafil in Malaysian, Singaporean, and Filipino men with erectile dysfunction. The Assess-1 Study Group.

OBJECTIVES: To evaluate the efficacy, safety, and tolerability of oral sildenafil in Asian men with erectile dysfunction of various causes (organic, psychogenic, or mixed) and of more than 6 months' duration. METHODS: In this double-blind, parallel-group trial conducted at eight centers in Malaysia, the Philippines, and Singapore, 254 men, 26 to 78 years old, were randomized to 12 weeks of sildenafil or placebo taken as needed 1 hour before anticipated sexual activity. Initially, the sildenafil (n = 127) or matching placebo (n = 127) dose was 50 mg but could be increased to 100 mg or decreased to 25 mg because of a lack of efficacy or intolerance, respectively. Efficacy was assessed by the 15-question International Index of Erectile Function, patients' event logs of sexual activity, and a global efficacy question about erections. RESULTS: The two primary efficacy variables relating to achievement and maintenance of an erection sufficient for sexual intercourse, as assessed by the mean scores for International Index of Erectile Function question 3 (4.22 versus 2.59) and question 4 (4.15 versus 2.41), were both significantly higher with sildenafil than with placebo (P <0.0001). In addition, the five separate International Index of Erectile Function domains of sexual function, the percentage of successful intercourse attempts, and the global efficacy assessment of erections revealed significantly greater treatment effects in favor of sildenafil (P <0.0001 versus placebo for all variables). Treatment-related adverse events occurred in 22.8% of patients who received sildenafil and in 10.2% of those who received placebo. CONCLUSIONS: Sildenafil is an effective and well-tolerated treatment for Asian men with erectile dysfunction of broad-spectrum etiology.

Adult↗