Skip to main content
Chan Yoo Kuen
  • Kuala Lumpur, Kuala Lumpur, Malaysia
Regional anesthesia is a safe, effective, and widely used modality for caesarean section delivery. In addition it is useful for controlling labor pain and postoperative pain. While severe complications are rare, common complications, such... more
Regional anesthesia is a safe, effective, and widely used modality for caesarean section delivery. In addition it is useful for controlling labor pain and postoperative pain. While severe complications are rare, common complications, such as hypotension, must be considered when using neuraxial anesthesia. Hypotension occurs in around half of individuals receiving central neuraxial block; coloading with crystalloid is a common method to prevent hypotension. Administration of vasopressors may be required to stabilize blood pressure. Local anesthetic toxicity is a potential complication, given the abundant vascularity of the epidural space; this presents concern for both parturient and fetus. Treating every epidural dose as a test dose can help avoid infusion of toxic doses. Paracervical and pudendal blocks are decreasing in popularity due to inadequate pain control and associated complications. Other complications to be considered in the obstetric population include neurologic dysfunction, infection, chronic adhesive arachnoiditis, postdural puncture headache, cauda equina lesion, damage to the spinal cord, transient neurologic symptoms, inadequate/extensive block, and rarely, respiratory and cardiac arrest.
Background: Complete heart block in pregnancy has serious implications particularly during the period of delivery. This is more so if the delivery is an operative one as the presence of heart block may produce haemodynamic instability in... more
Background: Complete heart block in pregnancy has serious implications particularly during the period of delivery. This is more so if the delivery is an operative one as the presence of heart block may produce haemodynamic instability in the intra operative period. We report a unique case of a pregnant mother with complete heart block undergoing hysterostomy, complicated by placenta accreta and intrauterine death. Case presentation: A 37 year old Malaysian Chinese parturient was admitted at 25 weeks gestation following a scan which suggested intrauterine death and placenta accreta. She was diagnosed to have congenital complete heart block after her first delivery eight years previously but a pacemaker was never inserted. These medical conditions make her extremely likely to experience massive bleeding and haemodynamic instability. Among the measures taken to optimise her pre-operatively were the insertion of a temporary intravenous pacemaker and embolization of the uterine arteries to minimize peri-operative blood loss. She successfully underwent surgery under general anesthesia, which was relatively uneventful and was discharged well on the fourth post-operative day. Conclusion: Congenital heart block in pregnancies in the presence of potential massive bleeding is best managed by a team, with meticulous pre-operative optimization. Suggested strategies would include insertion of a temporary pacemaker and embolization of the uterine arteries to reduce the risk of the patient getting into life threatening situations.
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... more
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.
Zulfiqar Bhutta and colleagues1 pose the question of what we can do to reduce stillbirth rates. Improving our understanding of the physiological processes behind sustaining life in utero might be useful to aid appropriate care provision.... more
Zulfiqar Bhutta and colleagues1 pose the question of what we can do to reduce stillbirth rates. Improving our understanding of the physiological processes behind sustaining life in utero might be useful to aid appropriate care provision.
Even healthy babies are compromised in utero. Being an end organ of the mother, the fetus's oxygen concentrations are exceedingly low,2 as shown by the high haemoglobin concentrations, the presence of fetal haemoglobin, and the special preferential flow to the myocardium and brain. Realising the precarious state of existence of all fetuses is a first step in recognition of the root cause of the problem.
The health of the placenta2, 3 is crucial to the life of the fetus. Delivery before the placenta undergoes senescence at 42 weeks in normal babies and before 38 weeks in diabetic women might prevent a substantial number of deaths or morbidity. Focus on placental function should be the basis of better care for the fetus.
Acute compromise in placental function as in abruptio placentae, rupture of the uterus, and maternal haemorrhage will cause immediate fetal compromise if not death. This is consistent with the inverse correlation4 between the availability of timely caesarean section and incidence of stillbirth. Timely intervention can reduce a high proportion of the damage currently seen.
Stillbirths, challenged babies,5 and healthy babies form a spectrum. They are the product of the nature of care we put into addressing their physiological needs in utero. Improving this knowledge might have a substantial effect on the kind of care we deliver to this under-recognised risk group.
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... more
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
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... more
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.kg(-1) (n=30), fentanyl 1 μ g.kg(-1) (n=30) or normal saline (n=30), before induction of anaesthesia with propofol 2.5 mg.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 [63% (2/30)] and saline groups [3.3% (1/30)]. We conclude that the addition of ketamine 0.5 mg.kg(-1) improves haemodynamics when compared to fentanyl 1 μ g.kg(-1), with less prolonged apnoea, and is associated with better LMA insertion conditions than placebo (saline).
Differences in sensitivity to anaesthetic drugs may exist among different ethnic groups. Allelic variants for drug metabolizing isoenzymes and pharmacokinetic differences may account for a variable response to some anaesthetic drugs. This... more
Differences in sensitivity to anaesthetic drugs may exist among different ethnic groups. Allelic variants for drug metabolizing isoenzymes and pharmacokinetic differences may account for a variable response to some anaesthetic drugs. This study was designed to compare propofol consumption and recovery characteristics in four ethnic groups: fo Chinese, Malays, and Indians in Malaysia and Caucasians in Italy. Patients undergoing total intravenous anaesthesia with propofol and fientanyl were evaluated for propofol consumption and recovery time. The Bispectral Index (BIS) was used to maintain the same anaesthesis depth in all patients. The BIS value, the response to verbal stimuli and eye-opening time were used to assess recovery. After propofol discontinuation the BIS values returned to baseline in 11+/-4.2 min for Caucasians, in 12.5+/-5.1 min for Chinese, 15.9+/-6.3 min for Malays and 22.1+/-8.1 for Indians. Time to eye-opening was 11.63+/-4.2 min in Caucasians, 13.23+/-4.9 min in Chinese, 16.97+/-5.2 min in Malays and 22.3+/-6.6 min in Indians. The propofol consumption was significantly lower in Indians compared to the other three groups (P<0.01). The recovery of Indians was much slower compared to Chinese, Malays and Caucasians. The recovery time of Malays is significantly slower compared to Chinese and Caucasians. Differences in propofol consumption and recovery time were not significant between Chinese and Caucasians, but the ratio recovery time/propofol consumption was significantly lower in Caucasians compared to all the othergroup.
A 5-year retrospective survey of anaesthesia for caesarean section for mild/moderate and severe preeclampsia was performed, covering the period between I January 1996 and 31 December 2000. One hundred and twenty-one cases of non-labouring... more
A 5-year retrospective survey of anaesthesia for caesarean section for mild/moderate and severe preeclampsia was performed, covering the period between I 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. (C) 2002 Elsevier Science Ltd. All rights reserved.
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... more
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 front a high of about 12% to the pre-epidural rate of 7%. (C) 2002 Elsevier Science Ltd. All rights reserved.
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... more
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.
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... more
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. (C) 2000 Harcourt Publishers Ltd.
Background To compare the maintenance and recovery characteristics of sevoflurane and isoflurane anaesthesia in Malaysian patients. Method This is a prospective, open labelled, randomized, controlled study. Sixty unpremedicated ASA I or... more
Background To compare the maintenance and recovery characteristics of sevoflurane and isoflurane anaesthesia in Malaysian patients.
Method This is a prospective, open labelled, randomized, controlled study. Sixty unpremedicated ASA I or II patients (aged 18-50 years), scheduled for elective breast lump excision were randomly allocated to receive either isoflurane or sevoflurane for the maintenance of anaesthesia following fentanyl and propofol intravenous induction. The systolic, diastolic, mean arterial blood pressure and heart rate were measured. The speed of recovery was measured by time to eye opening, time to following simple command, and time to correctly giving own names and address. The incidence of postoperative complication was also recorded.
Results The trend of systolic blood pressure was significantly higher in the isoflurane group as compared to the sevoflurane group for the duration of anaesthesia (p < 0.001, by ANOVA for repeated measurement) but the trend of heart rate was similar for both groups. The recovery time was faster in the isoflurane group. [mean time of eye opening (SD) = 6.8 (2.2) vs 10.7 (4.4) min, p < 0.001; mean time of sticking tongue out (SD) = 7.9 (2.9) vs 11.5 (4.7) min, p < 0.01; mean time of giving own name (SD) = 7.8 (2.7) vs 11.8 (4.8) min, p < 0.001, mean time of giving own address (SD) = 8.4 (2.9) vs 12.0 (4.7) min, p < 0.01]. No major adverse effects were encountered postoperatively and the incidences of minor adverse effects were low in both groups.
Conclusion We concluded that sevoflurane is a safe alternative to isoflurane but in these short procedures, awakening time was surprisingly slower than after isoflurane.
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... more
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. (C) 2000 Harcourt Publishers Ltd.
A healthy parturient under spinal anaesthesia for Caesarean section lost consciousness for an hour, 20 min after the intrathecal injection of 2 ml of 0.5% heavy bupivacaine. The patient was haemodynamically stable before losing... more
A healthy parturient under spinal anaesthesia for Caesarean section lost consciousness for an hour, 20 min after the intrathecal injection of 2 ml of 0.5% heavy bupivacaine. The patient was haemodynamically stable before losing consciousness. The differential diagnosis is discussed.
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... more
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.
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... more
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 mi of 0.5% bupivacaine had been given. Ten minutes after this dose they were given 10 mi of 0.5% bupivacaine and 50 mu g 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 intra-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.