MyMedR

Fulltext Technique of anaesthesia in pulmonary hypertension and thrombophilia in early pregnancy

Chuah KH, Mansor M, Rajen G, Wang CY, Chan YK

Med J Malaysia, 2006 Mar;61(1):114-6.

Pulmonary hypertension in pregnancy is a rare condition but is associated with a high mortality. We report the case of a 29 year old female in early pregnancy with Protein C and S deficiency with recurrent deep venous thrombosis and pulmonary embolism and subsequent secondary pulmonary hypertension. The patient was counselled and consented for termination of pregnancy with tubal sterilization. She was administered continuous spinal anaesthesia with invasive monitoring. The successful anaesthetic management of this condition is described.

Epidural analgesia in primigravidae in spontaneous labour at term: a prospective study

Leong EW, Sivanesaratnam V, Oh LL, Chan YK

J Obstet Gynaecol Res, 2000 Aug;26(4):271-5.

PMID: 11049237

OBJECTIVES: To prospectively study the intervention rate, duration of labour, malpositions, fetal outcome, maternal satisfaction, voiding complications and adverse events in healthy primigravidae in spontaneous labour at term following epidural analgesia.

METHODS: A prospective randomized study involving 55 patients in the epidural group and 68 in the control pethidine--inhalational entonox group.

RESULTS: There were significantly more obstetric interventions (instrumental deliveries) in the epidural group (p < 0.01). The total duration of labour and the duration of the second stage was prolonged in the epidural group (p < 0.01). There were more malpositions at the second stage of labour in the epidural group (p < 0.02). There were no differences in fetal outcome (Apgar scores and Special Care Nursery admissions). Patients in the epidural group were consistently happier with their method of pain relief (p < 0.01). Two patients required blood patches while another 2 patients had persistent backache post epidural analgesia.

CONCLUSION: Epidural analgesia in primigravidae in spontaneous labour at term led to an increased instrumental delivery rate, prolonged duration of labour, greater rate of malpositions in the second stage, increased oxytocin requirements but with no difference in fetal outcomes but with happier mothers as compared to the control group.

Fulltext A comparison of sodium citrate and sodium citrate/ranitidine combination for acid aspiration prophylaxis

Chan YK

Med J Malaysia, 1992 Mar;47(1):27-30.

PMID: 1387445

The effectiveness of sodium citrate and sodium citrate/ranitidine were compared in two randomised groups of elective caesarean patients during the various phases of anaesthesia. The mean pH values (3.5, 3.3, 3.6) were lower in the citrate group compared to the citrate/ranitidine group (6.1, 6.3, 5.9). The percentage of patients with pH values less than 2.5 was 40% in the citrate group compared to 7% in the citrate/ranitidine group. Sodium citrate alone is less effective than sodium citrate/ranitidine for acid aspiration prophylaxis.

Fulltext Outcome of neonates admitted to special care nursery, University Hospital, Kuala Lumpur: a comparison of two periods

Toh CK, Tan PC, Chan YK

Med J Malaysia, 1984 Mar;39(1):21-7.

PMID: 6513836

The overall mortality rate of babies delivered in the University Hospital, Kuala Lumpur has improved significantly from 18.5 in 1969-1971 to 9.9 per thousand live births in 1979-1981. This drop in mortality is also seen in those infants weighing 1001 - 2000 g at birth. Indian babies in the weight group 1001 - 1500 g at birth appear to have a significantly lower mortality than the other races. Babies referred from outside have a much higher mortality rate compared to babies delivered in University Hospital, Kuala Lumpur.

Which and what headache were we treating? Epidural blood patch for atypical headache following obstetric epidural anaesthesia

Chiu CL, Chan YK

Int J Obstet Anesth, 2000 Oct;9(4):273-5.

PMID: 15321079 DOI: 10.1054/ijoa.2000.0397

We present a case of headache following epidural anaesthesia for caesarean section. The patient did not exhibit the classical features of post dural puncture headache and the cause was uncertain. The headache was complicated by post partum seizure and a history of pregnancy-induced hypertension. A diagnostic lumbar puncture had to be done to exclude meningitis as she had a raised white blood count. An epidural blood patch performed 12 days post partum resolved the headache immediately.

Retrospective review of spinal versus epidural anaesthesia for caesarean section in preeclamptic patients

Chiu CL, Mansor M, Ng KP, Chan YK

Int J Obstet Anesth, 2003 Jan;12(1):23-7.

PMID: 15676316

A 5-year retrospective survey of anaesthesia for caesarean section for mild/moderate and severe preeclampsia was performed, covering the period between 1 January 1996 and 31 December 2000. One hundred and twenty-one cases of non-labouring preeclamptic patients receiving spinal or epidural anaesthesia for caesarean section were included for analysis. Comparisons were made of the lowest blood pressures recorded before induction of anaesthesia, during the period from induction to delivery and the period from delivery to the end of operation. The decreases in blood pressure were similar after spinal and epidural anaesthesia. The use of intravenous fluids and ephedrine were also comparable in the two anaesthetic groups. There was no difference in maternal or neonatal outcome. Our result supports the use of spinal anaesthesia in preeclamptic women.

Fulltext Radiological diagnosis of accidental oesophageal intubation

Chan YK

Singapore Med J, 1994 Jun;35(3):327-8.

PMID: 7997918

Oesophageal intubation is rapidly fatal if not recognised. We report a patient who not only survived an oesophageal intubation but who had chest X-rays taken which showed an oesophageal intubation which was initially recognised by the attending physician.

Trends in obstetric anaesthesia and analgesia over a ten year period in the University Malaya Medical Centre, Kuala Lumpur

Chan YK, Ng KP, Chiu CL

Int J Obstet Anesth, 2002 Jul;11(3):176-9.

PMID: 15321544 DOI: 10.1054/ijoa.2002.0954

Available data for obstetric care in the University Malaya Medical Centre, Kuala Lumpur from 1987 to 1999 were reviewed. Despite incomplete data, we were able to determine fairly well the practice of obstetric anaesthesia and analgesia in the unit, and the changes over the years. There was a decline in the use of general anaesthesia for both elective and emergency caesarean sections from 41.3% and 69.4% respectively in 1995 to 21.6% and 26.9% respectively in 1999. By 1999, regional anaesthesia had become the most common method of anaesthesia administered in both elective (14.3% epidural and 63.5% spinal) and emergency (30.2% epidural and 42.6% spinal) caesarean sections. The percentage of patients delivering vaginally who received epidural analgesia appeared to have stabilised at about 8 to 9% in the last few years, with a gradual decline in the total instrumental delivery rate from a high of about 12% to the pre-epidural rate of 7%.

Fulltext A comparison of the induction and emergence characteristics of sevoflurane and halothane in children

Chiu CL, Chan YK, Ong G, Delilkan AE

Med J Malaysia, 1999 Sep;54(3):346-51.

PMID: 11045061

This open labelled, randomised, controlled study was designed to compare the induction and recovery characteristics of sevoflurane and halothane anaesthesia in children. Forty American Society of Anaesthesiologist (ASA) physical status class 1 or 2 children (aged 1-10 year, weighed less than 25 kg) scheduled for elective urological procedure lasting less than one hour were allocated randomly to receive either sevoflurane (group S, n = 20) or halothane (group H, n = 20). The induction time in children receiving sevoflurane was significantly shorter than in those receiving halothane (mean (SD) 46 (13.6) second vs 69 (19.4) seconds, p < 0.005). The emergence from anaesthesia was also faster in children receiving sevoflurane than in those receiving halothane (mean (SD) 9 min (4.3 min) vs 21 min (8.9 min), p < 0.001). No major adverse effects were encountered in each group. We concluded that sevoflurane is comparable to halothane in Malaysian children.

Fulltext A comparison of the maintenance and recovery charcateristic of sevoflurane-nitrous oxide against isoflurane-nitrous oxide anaesthesia

Chiu CL, Chan YK, Ong GS, Delilkan AE

Singapore Med J, 2000 Nov;41(11):530-3.

PMID: 11284610

To compare the maintenance and recovery characteristics of sevoflurane and isoflurane anaesthesia in Malaysian patients.

Fulltext Hemodynamic monitoring and outcome-a physiological appraisal

Chan YK, Khan ZH

Acta Anaesthesiol Taiwan, 2011 Dec;49(4):154-8.

PMID: 22221689 DOI: 10.1016/j.aat.2011.11.002

Hemodynamic monitoring provides us with refined details about the cardiovascular system. In spite of increased availability of the monitoring process and monitoring equipment, hemodynamic monitoring has not significantly improved survival outcome. Care providers should be cognizant of the role of the cardiovascular system and its importance in oxygen delivery to the cells in order to sustain life. Effective hemodynamic monitoring should be able to delineate how well the system is performing in carrying out this role. Different hemodynamic monitors serve in this role to a different extent; some provide very little information on this. The cardiovascular system is only one of the many systems that need to function optimally for survival; others of equal importance include the integrity of the airway, the breathing process, the adequacy of hemoglobin level, and the health of the tissue bed, especially in the brain and the heart. Advances in hemodynamic monitoring with focus on oxygen delivery at the cellular level may ultimately provide the edge to effective monitoring that can impact outcome.

Fulltext A New Image Enhancement and Super Resolution technique for license plate recognition

Hamdi A, Chan YK, Koo VC

Heliyon, 2021 Nov;7(11):e08341.

PMID: 34825077 DOI: 10.1016/j.heliyon.2021.e08341

License Plate Recognition (LPR) is an important implemented application of Artificial Intelligence (AI) and deep learning in the past decades. However, due to the low image quality caused by the fast movement of vehicles and low-quality analogue cameras, many plate numbers cannot be recognised accurately by LPR models. To solve this issue, we propose a new deep learning architecture called D_GAN_ESR (Double Generative Adversarial Networks for Image Enhancement and Super Resolution) used for effective image denoising and super-resolution for license plate images. In this paper, we show the limitation of the existing networks for image enhancement and image super-resolution. Furthermore, a feature-based evaluation metric called Peak Signal to Noise Ratio Features (PSNR-F) is used to evaluate and compare performance between different methods. It is shown that the use of PSNR-F has a better performance indicator than the classical PSNR-pixel-to-pixel (PSNR-pixel) evaluation metric. The results show that using D_GAN_ESR to enhance the license plate images increases the LPR accuracy from 30% to 78% when blur images are used and increases the accuracy from 59% to 74.5% when low-quality images are used.

Anesthetic management of a parturient with superior vena cava obstruction for cesarean section

Chan YK, Ng KP, Chiu CL, Rajan G, Tan KC, Lim YC

Anesthesiology, 2001 Jan;94(1):167-9.

PMID: 11135739

Handedness in man: The energy availability hypothesis

Chan YK, Loh PS

Med Hypotheses, 2016 Sep;94:108-11.

PMID: 27515214 DOI: 10.1016/j.mehy.2016.06.018

More than 90% of the human species are right handed. Although outwardly our body appears symmetrical, a 50/50% lateralization in handedness never occurs. Neither have we seen more than 50% left handedness in any subset of the human population. By 12-15weeks of intrauterine life, as many as 6 times more fetuses are noted by ultrasound studies to be sucking on their right thumbs. Distinct difference in oxygenation leading to dissimilar energy availability between right and left subclavian arteries in place by week 9 of life may hold the clue to the lateralization of hand function and eventually, the same in the brain. We know there is a higher incidence of left handedness in males, twins, premature babies and those born to mothers who smoke. They may represent a subset with less distinct difference in oxygenation between the 2 subclavian arteries during the fetal stage. This hypothesis if correct not only closes the gap in understanding human handedness and lateralization but also opens a vista for new research to focus on in utero tissue energy availability and its impact on outcome in life.

Randomized double-blind comparison of ketamine-propofol, fentanyl-propofol and propofol-saline on haemodynamics and laryngeal mask airway insertion conditions

Goh PK, Chiu CL, Wang CY, Chan YK, Loo PL

Anaesth Intensive Care, 2005 Apr;33(2):223-8.

PMID: 15960405

The aim of this prospective, double-blind, randomized, placebo-controlled clinical trial was to investigate whether the administration of ketamine before induction with propofol improves its associated haemodynamic profile and laryngeal mask airway (LMA) insertion conditions. Ninety adult patients were randomly allocated to receive either ketamine 0.5 mg x kg(-1) (n = 30), fentanyl 1 microg x kg(-1) (n = 30) or normal saline (n = 30), before induction of anaesthesia with propofol 2.5 mg x kg(-1). Insertion of the LMA was performed 60s after injection of propofol. Arterial blood pressure and heart rate were measured before induction (baseline), immediately after induction, immediately before LMA insertion, immediately after LMA insertion and every minute for three minutes after LMA insertion. Following LMA insertion, the following six subjective endpoints were graded by a blinded anaesthestist using ordinal scales graded 1 to 3: mouth opening, gagging, swallowing, movement, laryngospasm and ease of insertion. Systolic blood pressure was significantly higher following ketamine than either fentanyl (P = 0.010) or saline (P = 0.0001). The median (interquartile range) summed score describing the overall insertion conditions were similar in the ketamine [median 7.0, interquartile range (6.0-8.0)] and fentanyl groups [median 7.0, interquartile range (6.0-8.0)]. Both appeared significantly better than the saline group [median 8.0, interquartile range (6.75-9.25); P = 0.024]. The incidence of prolonged apnoea (> 120s) was higher in the fentanyl group [23.1% (7/30)] compared with the ketamine [6.3% (2/30)] and saline groups [3.3% (1/30)]. We conclude that the addition of ketamine 0.5 mg x kg(-1) improves haemodynamics when compared to fentanyl 1 microg x kg(-1), with less prolonged apnoea, and is associated with better LMA insertion conditions than placebo (saline).

Education and Imaging. Gastrointestinal: massive intraperitoneal haemorrhage in a young woman with hereditary hemorrhagic telangiectasia

Sivarani S, Chan YK, Liam CK, Kumar G, Abdullah BJ, Mahadeva S

J Gastroenterol Hepatol, 2010 Sep;25(9):1587.

PMID: 20796159 DOI: 10.1111/j.1440-1746.2010.06469.x

Fulltext Safe delivery of two parturient women in severe metabolic acidosis

Shariffuddin II, Rai V, Chan YK, Muniandy RK

BMJ Case Rep, 2014;2014.

PMID: 24862427 DOI: 10.1136/bcr-2014-205135

Care of an acutely ill parturient is particularly difficult when we have to balance the needs of both mother and the fetus to survive. The literature suggests there should be emphasis on stabilising the mother's condition. In dealing with metabolic acidosis, however, we believe delivering the baby early might not only relieve the threat of the acidosis on the mother, it may be the only way to deliver a live baby. We report two parturient women with severe metabolic acidosis which was considerably reduced very soon after the delivery and how our timely delivery resulted in the birth of two neurologically intact babies.

A survey of the current practice of obstetric anaesthesia and analgesia in Malaysia [correction of Malaysis]

Chan YK, Ng KP

J Obstet Gynaecol Res, 2000 Apr;26(2):137-40.

PMID: 10870307

OBJECTIVE: A survey covering 30% of the deliveries in Malaysia was done to determine the practice of obstetric anaesthesia and analgesia for 1996.

RESULTS: From the survey, it was found that the regional anaesthesia rate for caesarean section was 46% in the government hospitals compared to 29.2% in the private hospitals, with spinal anaesthesia being the most common regional anaesthetic technique used in both types of hospitals. The epidural rate for labour analgesia was only 1.5% overall for the country. Epidural analgesia services were available in all private hospitals whereas 17.6% of government hospitals surveyed did not offer this service at all.

CONCLUSIONS: Although the use of epidural analgesia for labour was low in Malaysia, the overall rate of regional anaesthesia for caesarean section (41.9%) is very much in keeping with the standards of safe practice recommended by the United Kingdom.

A survey of regional analgesia and anaesthesia for obstetrics in selected countries in the Far East

Chan YK, Ng KP

Int J Obstet Anesth, 2000 Oct;9(4):225-32.

PMID: 15321075

A survey was conducted in several countries in the Far East in an attempt to determine the practice of obstetric analgesia and anaesthesia there. Survey forms were sent to a total of 11 countries but in the end responses from only four countries were able to provide useful information. Responses from Singapore, Hong Kong, Taiwan and Malaysia covered between 44.9% (Singapore) and 24.6% (Malaysia) of their countries' total deliveries in 1997 and were thought to be adequate to give an impression of the obstetric analgesia and anaesthesia services in their respective countries, although this would not necessarily be completely accurate. From our survey, we found that the availability of regional analgesia for labour paralleled the economic status of the country and that a significant number of caesarean sections are conducted under regional anaesthesia, mainly spinals.

Pain during elective caesarean section under epidural anaesthesia: the effect of a 10 degrees head-up tilt position

Chan YK, Ali A, Oh L

Int J Obstet Anesth, 1999 Apr;8(2):101-4.

PMID: 15321153

One hundred patients scheduled for elective caesarean section under epidural anaesthesia were randomized to have epidural loading doses in either the horizontal or a 10 degrees head-up position. They were assigned to their position only after an initial dose of 4 ml of 0.5% bupivacaine had been given. Ten minutes after this dose they were given 10 ml of 0.5% bupivacaine and 50 microg of fentanyl in their allocated position. Pain during surgery was assessed by the patients using a visual analogue scale and by a blinded anaesthetist. Giving the main dose in the head-up tilt position reduced the incidence of intea-operative pain significantly. The median pain score for the head-up position was zero while the score was two for the horizontal position. The inter-quartile range was 0 to 2 for the head-up tilt position and 0 to 4 for the horizontal position (P<0.05). Position had no significant effect on the blood pressure or Bromage score. A 10 degrees head-up tilt position is useful during the establishment of epidural anaesthesia to reduce the pain experienced by the patient during caesarean section.

Displaying publications 1 - 20 of 27 in total