Renal transplantation is the best treatment for end-stage renal disease, as it allows optimum rehabilitation with better survival than haemodialysis or peritoneal dialysis: in 2016, the annual mortality rate per 100 patient-years in Hong Kong was 1.88 for patients who received a renal transplant, 17.89 for patients on peritoneal dialysis, and 18.89 for those on haemodialysis.1 With a global shortage of cadaveric organs, living-related kidney donation has become an important alternative, especially in countries with a low cadaveric organ donation rate such as Japan. In Hong Kong, living-related kidney transplants account for an average of 14.8% of all renal transplants performed over the past 10 years.1 In this issue of the Hong Kong Medical Journal, the characteristics and clinical outcomes of living renal donors in Hong Kong are reported.2

Compared with a cadaveric kidney transplant, a living-related kidney transplant has a higher graft survival rate: the 10-year graft survival rate was 70% for cadaveric and 81% for living kidney transplant, and the 20-year graft survival rate was 44% for cadaveric and 61% for living kidney transplant.1 This is due to multiple factors that include matching for the most suitable donor, and elective surgery to minimise stress to the donor and cold ischaemic time of the kidney. According to the Hospital Authority Renal Registry, in 2016 the half-life of a cadaveric kidney transplant was 18 years, whereas that for a living kidney transplant was 30 years.1 Living-related kidney donation, however, carries potential risks to the donor. The short-term risks include those related to anaesthesia, bleeding, and infection. In the long term, there is an increased risk of hypertension and proteinuria,3 4 as well as hypertension, pre-eclampsia, and proteinuria during pregnancy.5

Laparoscopic nephrectomy rather than an open procedure is now the preferred approach in many transplant centres for living-kidney procurement. Comparative studies have shown a shorter hospital stay and less bleeding, although the ischaemic time is longer with the laparoscopic approach.6

In order to overcome the problem of ABO blood group or human leukocyte antigen incompatibility in living-related organ donation, paired kidney exchange is becoming popular in many countries. It may be a simple two-way exchange, a three-way exchange or, if an altruistic donor is available, a domino-paired exchange or altruistic donor chain (Fig). The longest chain was in 2012 in the United States and involved 30 kidneys and 60 patients. In preparation for paired kidney exchange in Hong Kong, the Food and Health Bureau plans to clarify the legal situation by submitting a proposal to the Legislative Council. Another means by which to overcome ABO blood group incompatibility is by a pre-transplant immunosuppressive protocol that includes plasmapheresis alone or together with rituximab.

Because of the potential risks to the donor, a cadaveric kidney is still preferred. In 2016, the cadaveric organ donation rate was 6.3 per million population in Hong Kong.1 Owing to the increasing gap between the number of patients requiring a transplant and the number of organs available, the waiting time for a cadaveric organ is increasing. The average waiting time is approximately 6 years but may also be as long as 28 years.1 Public education is essential to raise general awareness of the need for cadaveric organ donation. Other measures include increasing human resources for organ procurement in acute care hospitals, increasing the effectiveness of donor referral and management and organ procurement, and establishing an independent organ procurement organisation. These initiatives are vital in order to boost organ donation rate in Hong Kong.

The author has disclosed no conflicts of interest.

1. Hong Kong Hospital Authority Renal Registry; 2016.

2. Hong YL, Yee CH, Leung CB, et al. Characteristics and clinical outcomes of living renal donors in Hong Kong. Hong Kong Med J 2018;24:11-7. Crossref

3. Chu KH, Poon CK, Lam CM, et al. Long-term outcomes of living kidney donors: a single centre experience of 29 years. Nephrology (Carlton) 2012;17:85-8. Crossref

4. Okamoto M, Akioka K, Nobori S, et al. Short- and long-term donor outcomes after kidney donation: analysis of 601 cases over a 35-year period at Japanese single center. Transplantation 2009;87:419-23. Crossref

5. Ibrahim HN, Akkina SK, Leister E, et al. Pregnancy outcomes after kidney donation. Am J Transplant 2009;9:825-34. Crossref

6. Fonouni H, Mehrabi A, Golriz M, et al. Comparison of the laparoscopic versus open live donor nephrectomy: an overview of surgical complications and outcome. Langenbecks Arch Surg 2014;399:543-51. Crossref

Hong Kong is regarded as one of the cities with the most advanced medical technology. The survival for out-of-hospital cardiac arrest (OHCA), however, remains far from ideal. From a series in 2012-2013, only 2.3% of all OHCA patients survived to discharge, a rate considered low compared with other developed countries in Asia.1 2 Meanwhile, the survival-to-discharge rate for OHCA in Singapore has doubled over the last 10 years because of the improved emergency medical services response time and the successful public access defibrillation (PAD) programme.3

Early defibrillation is one of the most important elements in the Chain of Survival.4 Hong Kong has had a PAD programme for more than 20 years although there are no formal statistics for the number of automatic external defibrillators (AEDs). According to an estimation of one of the AED locator mobile app developers, there are approximately 5000 AEDs installed in publicly accessible areas. This is only one quarter of the number per population in Japan.5 Nonetheless, number of AEDs installed is not the only factor that dictates the success or not of a PAD programme. The accessibility of the AED will affect the time to first defibrillation. In other countries, AEDs can be accessed by anyone. They can be found in convenience stores, vending machines, and even in taxis. On the contrary, a number of AEDs in Hong Kong can be accessed only via security staff or customer service personnel. This indirect approach will inevitably delay the time to first defibrillation. Even worse, despite the established benefit of AED in early defibrillation, misconceptions remain about individual liability when using an AED. This is evidenced by the disclaimer, which restricts use of AEDs to trained persons, that accompanies some locally installed AEDs.

Despite the availability of AEDs, a PAD programme is doomed to failure if AEDs are not used. A local study showed that public knowledge about AEDs was inadequate and fewer than 20% of respondents to a survey would use one.6 The lack of enactment of a Good Samaritan law may not reassure members of the public about possible liability when using an AED, even though they are designed to be operated by a layperson. On 1 October 2017, Mainland China enacted this law under Cap 184 of the Civil Law of the People’s Republic of China.7 There is a real need for Hong Kong to explore a similar enactment. We should also consider broadening the spectrum of cardiopulmonary resuscitation (CPR) and AED promulgation, eg mandatory CPR and AED training in secondary schools to teach this life-saving skill and relieve anxiety about initiating help.

Scientific research can also facilitate the PAD programme. In Singapore, national data revealed that the majority of OHCAs occur at home. The government responded by installing AEDs in all public housing estates.8 Lack of a territory-wide cardiac arrest registry and AED registry in Hong Kong may affect the cost-effectiveness of the PAD programme. The study by Fan et al1 is a good start but we need a continuous registry, like the Cancer Registry, to observe the ongoing trend of cardiac arrests.

At an international level, the Global Resuscitation Alliance (GRA) was established in 2016 and comprised a group of international experts in resuscitation. It aimed to improve the survival of OHCA by modifying the system in the community for response to an OHCA. Establishing a PAD programme was one of the 10 steps identified by the GRA for improving survival.9 At a local level, we need a strategic plan for a PAD programme, including using local OHCA data to coordinate the placement of AEDs as well as establishment of an AED registry. Together, these will facilitate technological advances such as a mobile phone app and enhance the accessibility of AED.10 The Resuscitation Council of Hong Kong was established in 2012 with the aim of promoting CPR and AED in the community. As well as routine public promotion activities, the Council also advocated relevant policy change in Hong Kong to promote a CPR- and AED-friendly environment. In the near future, the Council will focus on the establishment of an electronic AED Registry and enactment of the Good Samaritan law.11

The author has disclosed no conflicts of interest.

1. Fan KL, Leung LP, Siu YC. Out-of-hospital cardiac arrest in Hong Kong: a territory wide study. Hong Kong Med J 2017;23:48-53. Crossref

2. Ong ME, Shin SD, De Souza NN, et al. Outcomes for out-of-hospital cardiac arrests across 7 countries in Asia: The Pan Asian Resuscitation Outcomes Study (PAROS). Resuscitation 2015;96:100-8. Crossref

3. Lai H, Choong CV, Fook-Chong S, et al. Interventional strategies associated with improvements in survival for out-of-hospital cardiac arrests in Singapore over 10 years. Resuscitation 2015;89:155-61.

4. Kleinmann ME, Brennan EE, Goldberger ZD, et al. Part 5: Adult basic life support and cardiopulmonary resuscitation quality. 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 2015;132(18 Suppl 2):S414-35. Crossref

5. Iwami T. Effectiveness of public access defibrillation with AEDs for out-of-hospital cardiac arrests in Japan. Japan Med Assoc J 2012;55:225-30.

6. Fan KL, Leung LP, Poon HT, Chiu HY, Liu HL, Tang WY. Public knowledge of how to use an automatic external defibrillator in out-of-hospital cardiac arrest in Hong Kong. Hong Kong Med J 2016;22:582-8. Crossref

7. 中華人民共和國民法總則. Available from: http://www. npc.gov.cn/npc/xinwen/2017-03/15/content_2018907.htm. Accessed 1 Oct 2017.

8. Lee CY, Anatharaman V, Lim SH, et al. Singapore Defibrillation Guidelines 2016. Singapore Med J 2017;58:354-59. Crossref

9. Resuscitation Academy. 10 Steps for improving survival from sudden cardiac arrest. Available from: http://www. resuscitationacademy.org/downloads/ebook/TenStepsforImprovingSurvivalFromSuddenCardiacArrest-RA-eBook-PDFFinal-v1_2.pdf. Accessed 18 Sep 2017.

10. Fan KL, Lui CT, Leung LP. Public access defibrillation in Hong Kong in 2017. Hong Kong Med J 2017;23:635-40. Crossref

11. Wai AK. Protection of rescuers in emergency care: where does Hong Kong stand? Hong Kong Med J 2017;23:656-7. Crossref

On 14 December 2016, the US Food and Drug Administration (FDA) issued a warning that the repeated or lengthy use of general anaesthetic and sedative drugs in children under 3 years old and in pregnant women in their third trimester may affect the development of children’s brains. Warning labels were required to be added to general anaesthetic and sedative drugs.1

Data from published studies in pregnant and young animals have shown that the use of general anaesthetics increases the chance of apoptosis and neurodegeneration in the developing brain. Persistent memory and learning disabilities have been demonstrated2 3 as well as increased severity with increasing duration of anaesthesia.4 Certain human studies suggest an association between anaesthesia and subsequent behaviour or learning issues such as autism, attention-deficit disorder, and language deficits.5 6 7 Some researchers postulate that even relatively simple anaesthesia of babies and young children can pose a risk of neurotoxicity. The question is whether or not we can translate such animal data to humans and to what extent we should interpret the animal findings.8

For many years well-designed human studies were lacking. Data were mainly observational and retrospective, and with too many confounding factors. There were often conflicting results in different studies.9 10 Recently, however, more robust human studies have been published such as General Anaesthesia compared to Spinal anaesthesia (GAS) study11 and Pediatric Anesthesia NeuroDevelopment Assessment (PANDA).12 13 The GAS study, which compares children less than 60 weeks’ post-gestational age (but older than 26 weeks’ post gestation) undergoing hernia surgery under either general anaesthesia or awake regional anaesthesia, has shown that at the 2-year mark (secondary outcome), there is no increase in risk of learning disability. This study is ongoing with its primary outcome being the Wechsler Preschool and Primary Scale of Intelligence Third Edition Full Scale Intelligence Quotient score at 5 years old. The PANDA study was a sibling-matched cohort observational study that examined whether anaesthesia exposure in healthy children younger than 3 years old is associated with an increased risk of impaired global cognitive function as the primary outcome. Their secondary outcome was abnormal domain-specific neurocognitive function and behaviour at the ages of 8 to 15 years. The study found no significant difference between the exposed and unexposed in terms of both primary and secondary outcomes. Both studies point towards a slightly more reassuring outlook for short-duration exposure to anaesthesia in children.

Although a FDA warning on anaesthesia and exposure to anaesthetic drugs in paediatric, neonatal, and third-trimester pregnant women has been long expected, the timing of this warning came as a surprise to many in the paediatric anaesthesia community, particularly in light of the recent findings of the more sanguine and robust human studies and no new evidence of detrimental effects of anaesthesia.

Moreover, the FDA uses a cut-off age of 3 years old. This age limit is highly debatable since there is currently no evidence to support the use of 3 years as a cut-off or that anaesthesia in infants older than 3 years will not be harmful; and vice versa. Some use 3 years as a cut-off for the period of rapid neurodevelopment in a child; nonetheless a few retrospective cohort studies point towards anaesthesia affecting children of an older age-group.14 15 Many of these concerns are likely to be applicable to all patients undergoing surgery with those at the extremes of age being more vulnerable. Duration of surgery and the extent of tissue trauma, need for blood transfusion, and the choice of anaesthetic agent are also important variables.

Data from the American Society of Anesthesiologists (ASA) Closed Claims Project were analysed and revealed that children under 1 year of age with associated disease were at increased risk of major and minor morbidity.16 Cardiac arrests related to anaesthesia most often occurred in infants who were ASA status 3 to 5 and undergoing emergency procedures. Paediatric anaesthesiologists should therefore collaborate with surgeons to determine the best time for surgery in a child.17 Often, children need anaesthesia for operations or procedures that should not be delayed. In these cases, it is easier to balance the detrimental effects of not having the surgery against the potential risk of anaesthesia. In non-urgent surgeries that will not affect the child or the outcome of the operation if postponed until later in life, it is reasonable to discuss with all parties involved, including their parents or guardians, as to whether deferring the surgery can be considered in very young children. Given that perioperative complications are more common in the very young,18 this is a good general principle that has always been advocated by those involved in perioperative paediatric care, notwithstanding this FDA warning.

1. FDA Drug Safety Communication: FDA review results in new warnings about using general anesthetics and sedation drugs in young children and pregnant women. Available from: https://www.fda.gov/Drugs/DrugSafety/ucm532356.htm. Accessed Jul 2017.

2. Jevtovic-Todorovic V, Hartman RE, Izumi Y, et al. Early exposure to common anesthetic agents causes widespread neurodegeneration in the developing rat brain and persistent learning deficits. J Neurosci 2003;23:876-82. Crossref

3. Vutskits L, Xie Z. Lasting impact of general anaesthesia on the brain: mechanisms and relevance. Nat Rev Neurosci 2016;17:705-17. Crossref

4. Zou X, Patterson TA, Divine RL, et al. Prolonged exposure to ketamine increases neurodegeneration in the developing monkey brain. Int J Dev Neurosci 2009;27:727-31. Crossref

5. Hansen TG. Anesthesia-related neurotoxicity and the developing animal brain is not a significant problem in children. Paediatr Anaesth 2015;25:65-72. Crossref

6. Ing C, DiMaggio C, Whitehouse A, et al. Long-term differences in language and cognitive function after childhood exposure to anesthesia. Pediatrics 2012;130:e476-85. Crossref

7. Ing CH, DiMaggio CJ, Malacova E, et al. Comparative analysis of outcome measures used in examining neurodevelopmental effects of early childhood anesthesia exposure. Anesthesiology 2014;120:1319-32. Crossref

8. Todd MM. Anesthetic neurotoxicity: the collision between laboratory neuroscience and clinical medicine. Anesthesiology 2004;101:272-3. Crossref

9. Hansen TG, Pedersen JK, Henneberg SW, et al. Academic performance in adolescence after inguinal hernia repair in infancy: a nationwide cohort study. Anesthesiology 2011;114:1076-85. Crossref

10. Hansen TG, Pedersen JK, Henneberg SW, Morton NS, Christensen K. Educational outcome in adolescence following pyloric stenosis repair before 3 months of age: a nationwide cohort study. Paediatr Anaesth 2013;23:883-90. Crossref

11. Davidson AJ, Disma N, de Graaff JC, et al. Neurodevelopmental outcome at 2 years of age after general anaesthesia and awake-regional anaesthesia in infancy (GAS): an international multicentre, randomised controlled trial. Lancet 2016;387:239-50. Crossref

12. Sun LS, Li G, Miller TL, et al. Association between a single general anesthesia exposure before age 36 months and neurocognitive outcomes in later childhood. JAMA 2016;315:2312-20. Crossref

13. Chinn GA, Sasaki Russell JM, Sall JW. Is a short anesthetic exposure in children safe? Time will tell: a focused commentary of the GAS and PANDA trials. Ann Transl Med 2016;4:408. Crossref

14. Graham MR, Brownell M, Chateau DG, Dragan RD, Burchill C, Fransoo RR. Neurodevelopmental assessment in kindergarten in children exposed to general anesthesia before the age of 4 years: a retrospective matched cohort study. Anesthesiology 2016;125:667-77. Crossref

15. O’Leary JD, Janus M, Duku E, et al. A population-based study evaluating the association between surgery in early life and children development at primary school entry. Anesthesiology 2016;125:272-9. Crossref

16. Jimenez N, Posner KL, Cheney FW, Caplan RA, Lee LA, Domino KB. An update on pediatric anesthesia liability: a closed claims analysis. Anesth Analg 2007;104:147-53. Crossref

17. Paterson N, Waterhouse P. Risk in paediatric anesthesia. Pediatr Anaesth 2011;21:848-57. Crossref

18. Weiss M, Hansen TG, Engelhardt T. Ensuring safe anaesthesia for neonates, infants and young children: what really matters. Arch Dis Child 2016;101:650-2. Crossref

Historically, the introduction of caesarean section (CS) was associated with an improvement in maternal and perinatal health outcomes. In 1985, the World Health Organization (WHO) recommended that CS should not account for more than 10% to 15% of all births.1 The WHO has recently revised their position and stated that “every effort should be made to provide a CS to women in need, rather than striving to achieve a specific rate.”2 The effect of CS rates on other outcomes—such as maternal and perinatal morbidity, paediatric outcomes, and psychological or social well-being—are still unclear.2 Of note, CS carries its own risks for maternal and infant morbidity and for subsequent pregnancies. At some point, these risks will outweigh the potential benefits associated with lowering the threshold at which the procedure becomes indicated.

In recent decades, there has been a rising tide in CS worldwide with a wide variation in CS rate among various countries from approximately 16% to more than 60%.3 The reasons for the increase in CS rates are multiple and complex, but have been attributed to the increasing prevalence of older mothers, rising rates of maternal obesity and medical co-morbidities, and changing medical practice including a relative increased safety of CS itself.4 5 6 7 In addition, there is substantial evidence that this increase is more prevalent among women with privately funded deliveries.8 9 Nevertheless, the dramatic rise in CS rate has not been shown to be accompanied by any substantial decrease in maternal or perinatal morbidity or mortality.10 Malpractice litigation pressure has been suggested as one of the attributes for the rise because associations have been demonstrated between CS rates and malpractice premiums.11

In Hong Kong, the annual CS rate rose steadily from 16.6% to 27.4% from 1987 to 1999, with the rate in private institutions of 27.4% higher than the public sector.9 Published in this issue of the Hong Kong Medical Journal, a retrospective review of CS rates from 1995 to 2014 at a local public hospital by Chung et al12 shows that the overall rate increased modestly from 15.4% to 24.6%. Nonetheless, it is well known by women in Hong Kong that government-funded units under the Hospital Authority do not perform elective CS for non-clinical indications. Those with a strong preference for elective CS might seek private maternity care. The territory-wide audit conducted by the Hong Kong College of Obstetricians and Gynaecologists has documented an increase in overall CS rates in Hong Kong from 27.1% in 1999 to 30.4% in 2004 and 42.1% in 2009.13 The latest annual obstetric report of the Hospital Authority in 2015 showed CS rates in the eight public hospitals in Hong Kong varying from 21.7% to 30.4%.14

The WHO recently adopted the Robson’s classification system as a global standard for assessing, monitoring, and comparing CS rates.2 Robson’s system classifies women into 10 groups based on five obstetric characteristics that are routinely documented: parity, onset of labour, gestational age, fetal presentation, and number of fetuses. The actual indication for CS is not needed for categorisation. The categories in Robson’s system are mutually exclusive, totally inclusive, and can be applied prospectively.15 It allows comparison of clinically meaningful maternity population subgroups and their associated CS rates across institutions, country development groups, and time. The Robson’s classification has been used to analyse trends and determinants of CS rates in high- and low-income countries, such as the data analysis of 21 countries included in the WHO survey.16 The retrospective review by Chung et al12 used the Robson’s classification system to categorise a 20-year database up to 2014. It showed dramatic and statistically significant increases (P<0.001) in CS rate in those with previous CS (rising from 29% to 61%), breech presentation at delivery (primiparous from 72% to 97% and multiparous from 69% to 96%), and multiple pregnancies (from 35% to 86%). The authors suggested that the rise in the previous CS group was secondary to a more liberal policy to allow patients to choose CS after abandonment of pelvimetry to predict successful trial of labour. The increased CS rate in breech presentation group may be due to publication of the Term Breech Trial in 2000, whereas the increase in the multiple pregnancy group was attributed to the liberal policy that accommodated patient expectations. Nonetheless, a significant fall from 14% to 11% was noted in the group of primiparous patients with term spontaneous labour. Such progressive drop in CS rate was a result of the adoption of evidence-based active management of labour protocols, and regular audits in CS rates and indications within the unit.

A local cross-sectional survey of 660 Chinese pregnant women in a government-funded obstetric unit in Hong Kong found that previous CS and conception by in-vitro fertilisation were significant determinants of a preference for elective CS.17 In another local retrospective cohort study of twin pregnancies, conception by assisted reproduction was also a statistically significant factor that affected maternal preference for elective CS.18 Non-cephalic presentation of the second twin was another statistically significant factor in the study, indicating women’s concern for their babies when considering mode of delivery. The survey also showed that women who preferred elective CS were concerned about safety of the baby, and feared a vaginal birth and the pain associated with the delivery.

Two randomised controlled trials aimed to determine whether interventions were useful to reduce the number of women seeking CS. One focused on using an individualised prenatal educational programme in women with previous CS19 and the other used cognitive treatment in women who were fearful of a vaginal birth.20 Both showed no significant difference between intervention and control groups with respect to the women’s request for elective CS. These results may imply that once fear is established, treatment is not of significant clinical benefit.

To reduce the overall CS rate, reducing the proportion of first deliveries by CS appears pertinent. Public and prenatal education may play an important role in shaping expectations. Obstetric management protocols, skills, and clinical audits can be targeted at reducing first birth by CS, eg external cephalic version in term-breech pregnancies, safe vaginal twin delivery techniques, standardised fetal heart rate tracing interpretation and management, and increasing women’s access to non-medical interventions during labour such as labour and delivery support. More drastic attempts to curb primary CS rates in primiparous women can be considered, such as redefining labour dystocia, postponing the cut-off for active labour at 6-cm dilatation, allowing adequate time for the second stage of labour, or encouraging operative vaginal delivery.10 Last but not least, obstetricians should fully discuss the risks and benefits of a vaginal birth versus CS, especially when CS is requested without a clinical indication. In such cases it is important to explore, discuss, and record the specific reasons for the request, and to include a discussion with other members of the obstetric team (including obstetrician, midwife, and anaesthetist) if necessary to explore the reasons for the request and ensure the woman has accurate information.21 The skill needed to make a balanced clinical decision for an individual woman may perhaps be greater than that required to undertake the procedure.

1. Appropriate technology for birth. Lancet 1985;2:436-7.

2. World Health Organization. WHO statement on caesarean section rates. April 2015. Available from: http://apps.who.int/iris/bitstream/10665/161442/1/WHO_RHR_15.02_eng.pdf?ua=1. Accessed Jun 2017.

3. Visser GH. Women are designed to deliver vaginally and not by caesarean section: an obstetrician’s view. Neonatalogy 2015;107:8-13. Crossref

4. O’Dwyer V, Farah N, Fattah C, O’Connor N, Kennelly MM, Turner MJ. The risk of caesarean section in obese women analysed by parity. Eur J Obstet Gynecol Reprod Biol 2011;158:28-32. Crossref

5. Brick A, Layte R. Recent trends in the caesarean section rate in Ireland 1999-2006. ESRI Working Paper No. 309. August 2009. Available from: https://www.esri.ie/pubs/WP309.pdf. Accessed Jun 2017.

6. Brick A, Layte R. Exploring trends in the rate of caesarean section in Ireland 1999-2007. Econ Soc Rev (Irel) 2011;42:383-406.

7. Bayrampour H, Heaman M. Advanced maternal age and the risk of cesarean birth: a systematic review. Birth 2010;37:219-26. Crossref

8. Lipkind HS, Duzyj C, Rosenberg TJ, Funai EF, Chavkin W, Ciasson MA. Disparities in caesarean delivery rates and associated adverse neonatal outcomes in New York City hospitals. Obstet Gynecol 2009;113:1239-47. Crossref

9. Leung GM, Lam TH, Thach TQ, Wan S, Ho LM. Rates of cesarean births in Hong Kong: 1987-1999. Birth 2001;28:166-72. Crossref

10. American College of Obstetricians and Gynecologists (College); Society for Maternal-Fetal Medicine; Caughey AG, Cahill AG, Guise JM, Rouse DJ. Safe prevention of the primary caesarean delivery. Am J Obstet Gynecol 2014;210:179-93. Crossref

11. Yang YT, Mello MM, Subramanian SV, Studdert DM. Relationship between malpractice litigation pressure and rates of cesarean section and vaginal birth after caesarean section. Med Care 2009;47:234-42. Crossref

12. Chung WH, Kong CW, To WW. Secular trends in caesarean section rates over 20 years in a regional obstetric unit in Hong Kong. Hong Kong Med J 2017;23:340-8. Crossref

13. Territory-wide audit in obstetrics and gynaecology. Hong Kong: The Hong Kong College of Obstetricians and Gynaecologists; 2014.

14. Hospital Authority Obstetric Annual Report 2015. Hong Kong: Hospital Authority; 2016.

15. Torloni MR, Betran AP, Souza JP, et al. Classifications for cesarean section: a systematic review. PLoS One 2011;6:e14566. Crossref

16. Vogel JP, Betrán AP, Vindevoghel N, et al. Use of the Robson classification to assess caesarean section trends in 21 countries: a secondary analysis of two WHO multicountry surveys. Lancet Glob Health 2015;3:e260-70. Crossref

17. Pang SM, Leung DT, Leung TY, Lai CY, Lau TK, Chung TK. Determinants of preference for elective caesarean section in Hong Kong Chinese pregnant women. Hong Kong Med J 2007;13:100-5.

18. Liu AL, Yung WK, Yeung HN, et al. Factors influencing the mode of delivery and associated pregnancy outcomes for twins: a retrospective cohort study in a public hospital. Hong Kong Med J 2012;18:99-107.

19. Fraser W, Maunsell E, Hodnett E, Moutquin JM. Randomized controlled trial of a prenatal vaginal birth after cesarean section education and support program. Childbirth Alternatives Post-Cesarean Study Group. Am J Obstet Gynecol 1997;176:419-25. Crossref

20. Saisto T, Salmela-Aro K, Nurmi JE, Könönen T, Halmesmäki E. A randomized controlled trial of intervention in fear of childbirth. Obstet Gynecol 2001;98(5 Pt 1):820-6. Crossref

21. National Institute for Health and Care Excellence. NICE Clinical guideline: Caesarean section (CG132). 2012. Available from: https://www.nice.org.uk/guidance/cg132. Accessed Jun 2017.

Dementia affects 47 million people worldwide.1 Persons with dementia require appropriate diagnostic investigations, treatments, and long-term care. The economic impact of dementia is huge. Globally, the total estimated worldwide cost of dementia is US$818 billion.1 In Hong Kong, the estimated number of persons with dementia was 103 433 among those aged 60 years or above in 2009, and this number is projected to increase to 332 688 by 2039.2 Dementia is a clinical syndrome due to a variety of causes. The most common is Alzheimer’s disease (AD) followed by vascular dementia.3 Other causes include dementia with Lewy bodies (DLB), Parkinson’s disease dementia (PDD), and frontotemporal dementia. Clinical diagnosis is often based on clinical features, with reference to the clinical criteria.4 5 6 7 Overlap of the clinical features of different dementias is common and may result in an incorrect clinical diagnosis. Notably, recent studies have confirmed the role of structural (magnetic resonance imaging [MRI]), functional ([¹⁸F]-2-fluoro-2-deoxy-D-glucose positron emission tomography [¹⁸FDG-PET] or single-photon emission computed tomography [SPECT]), and amyloid pathology (carbon 11–labelled Pittsburgh compound B) brain imaging in improving the accuracy of clinical differential diagnosis of AD versus other dementia subtypes.4 8 9 For example, volumetric MRI hippocampal volumes differentiate AD from healthy elderly adults with over 80% accuracy. Recently, this has been applied in clinical practice and is preferred to the semiquantitative visual hippocampal assessment that has only 81% sensitivity and 67% specificity for AD diagnosis.4 Furthermore, new amyloid and tau PET neuroimaging for preclinical AD diagnosis will also be available soon for clinical application.9

Compared with AD, DLB and PDD are much less prevalent in Chinese than in Caucasian populations. In this issue of the Hong Kong Medical Journal, Shea et al10 reports a Chinese case series of 16 DLB and seven PDD patients from a memory clinic in Hong Kong. In contrast with the first reported series of 31 DLB and four PDD Chinese patients from Mainland China, which employed clinical assessment only,11 Shea et al10 included functional brain imaging with ¹⁸FDG-PET or technetium-99m hexamethylpropylene amine oxime SPECT in the diagnostic assessment, with hypometabolism or hypoperfusion of occipital lobes, respectively as positive evidence of DLB/PDD. With these tools, they studied the diagnostic inaccuracy of clinical assessment alone. Pre-imaging accuracy of clinical diagnosis was only 52%, confirming the clinical utility of adding these imaging investigations to improve diagnostic accuracy in clinical practice.10 The spectrum of disorders with Lewy body embraces a spectrum of neurodegenerative diseases, including Parkinson’s disease, PDD and DLB, that are due to the abnormal neuronal accumulation of the protein α-synucleinopathies in the brainstem, limbic, and neocortical regions. In the diagnostic criteria, a ‘1-year’ duration between the onset of Parkinsonism and dementia symptoms is an arbitrary criterion to clinically distinguish PDD and DLB.9 12 This is being reviewed by the International Parkinson and Movement Disorder Society and may be deleted in the future.9

In elderly patients, multiple co-morbidities are common: AD may coexist with DLB and PDD in the same patient. Shea et al10 found that 52% (12 out of 23) of patients with DLB/PDD had an AD pattern of functional imaging abnormalities (ie bilateral temporoparietal lobes hypometabolism/hypoperfusion), showing that AD actually coexisted in approximately 50% of their DLB/PDD patients. This finding also explained why 38% of them were initially diagnosed with AD.10 The presence of AD in these patients represented additional co-morbid disease and was not a ‘misdiagnosis’.

Clinically, confirming the diagnosis of DLB or PDD in these patients had an important bearing on subsequent treatments. First, clinicians should avoid the use of neuroleptic drugs in these patients, owing to a high risk of neuroleptic syndrome in DLB/PDD. Second, cholinesterase inhibitors should be tried as they are beneficial in alleviating cognitive symptoms in DLB and PDD patients. Third, levodopa/carbidopa treatment of Parkinsonism motor symptoms may be complicated by a worsening of hallucinations.13 With progressive neuronal degeneration, both dementia and Parkinsonism motor symptoms will deteriorate with time. For their DLB and PDD patients, Shea et al10 reported a 30% mortality on follow-up (mean, 3.1 years), and 70%, 26%, 52%, and 26% of patients had falls, pressure sores, dysphagia, and aspiration pneumonia, respectively.

In general, most dementias are neurodegenerative in nature. The disease pathology may start in the brain 10 to 20 years before onset of dementia symptoms. With increasing dementia severity over the years, loss of self-care ability and eventually the ability to eat will occur in the final stage of the dementia illness. Feeding problems lead to weight loss, malnutrition, impaired immunity to infection, and poor wound healing. In the current issue of this Journal, Luk et al14 reviewed the clinical and ethical issues related to feeding problems in advanced dementia patients in Hong Kong. As emphasised by the authors, the key issue was the high prevalence of tube feeding: 53% among advanced dementia persons living in old-age homes.14 15 The reasons for giving tube feeding included dysphagia, inadequate eating, and malnutrition. Tube feeding, however, did not prevent aspiration pneumonia, nor did it yield any benefit for survival. Nasogastric tube feeding also induced nasal discomfort in these demented persons and prompted attempts to self-remove the tube. The latter might lead to an increased chance of being restrained, as well as repeated hospital visits for replacement of the nasogastric tube. Some of these patients might not need a feeding tube,14 and ‘careful hand feeding’ could offer a viable alternative. This may work well for patients who have lost their motivation to eat but still retain their ability to swallow. Formal assessment by the speech therapist should be carried out to confirm this ability. In these patients, careful hand feeding should be tried first. A trial of antidepressants may be given if depressive mood is also present. It should be noted that careful hand feeding is not effective for advanced demented patients with genuine dysphagia in whom the risk of aspiration and aspiration pneumonia is high. Withholding feeding is another option for these patients. Obviously, the harm of withholding feeding includes dehydration, malnutrition, and eventually death. The dilemma of whether to start tube feeding or to stop feeding remains a clinical and ethical challenge for both the physician and family. In this context, the presence of an advance directive of the patient will help guide clinical treatment and care decisions. With an advance directive, a mentally competent person can indicate the form of health care he or she would like to receive in the future. In this regard, the directive must include the use or non-use of tube feeding.16 It should be noted that several local studies have previously confirmed the acceptability and feasibility of advance directives among Chinese adult and elderly patients in Hong Kong.17 18 19 Most demented patients, however, do not have written advance directives before becoming mentally incompetent. Our current challenge now lies in the promotion of the use of advance directives among Hong Kong citizens, while they are still mentally competent, and encouragement to formulate one.

1. World Alzheimer Report 2016. Improving healthcare for people living with dementia. Coverage, quality and costs now and in the future. Alzheimer’s Disease International. Available from: https://www.alz.co.uk/research/WorldAlzheimerReport2016.pdf. Accessed 10 Apr 2017.

2. Yu R, Chau PH, McGhee SM, et al. Trends in prevalence and mortality of dementia in elderly Hong Kong population: projections, disease burden, and implications for long-term care. Int J Alzheimers Dis 2012;2012:406852. Crossref

3. Chiu HF, Lam LC, Chi I, et al. Prevalence of dementia in Chinese elderly in Hong Kong. Neurology 1998;50:1002-9. Crossref

4. Chu LW. Alzheimer’s disease: early diagnosis and treatment. Hong Kong Med J 2012;18:228-37.

5. McKhann GM, Knopman DS, Chertkow H, et al. The diagnosis of dementia due to Alzheimer’s disease: recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement 2011;7:263-9. Crossref

6. McKeith IG, Dickson DW, Lowe J, et al. Diagnosis and management of dementia with Lewy bodies: third report of the DLB Consortium. Neurology 2005;65:1863-72. Erratum in: Neurology 2005;65:1992. Crossref

7. Rascovsky K, Hodges JR, Knopman D, et al. Sensitivity of revised diagnostic criteria for the behavioural variant of frontotemporal dementia. Brain 2011;134:2456-77. Crossref

8. Shea YF, Ha J, Lee SC, Chu LW. Impact of (18)FDG PET and (11)C-PIB PET brain imaging on the diagnosis of Alzheimer’s disease and other dementias in a regional memory clinic in Hong Kong. Hong Kong Med J 2016;22:327-33. Crossref

9. Saeed U, Compagnone J, Aviv RI, et al. Imaging biomarkers in Parkinson’s disease and Parkinsonian syndromes: current and emerging concepts. Transl Neurodegener 2017;6:8. Crossref

10. Shea YF, Chu LW, Lee SC. A descriptive study of Lewy body dementia with functional imaging support in a Chinese population: a preliminary study. Hong Kong Med J 2017;23:222-30. Crossref

11. Han D, Wang Q, Gao Z, Chen T, Wang Z. Clinical features of dementia with lewy bodies in 35 Chinese patients. Transl Neurodegener 2014;3:1. Crossref

12. Walker Z, Possin KL, Boeve BF, Aarsland D. Lewy body dementias. Lancet 2015;386:1683-97. Crossref

13. O’Brien JT, Holmes C, Jones M, et al. Clinical practice with anti-dementia drugs: A revised (third) consensus statement from the British Association for Psychopharmacology. J Psychopharmacol 2017;31:147-68. Crossref

14. Luk JK, Chan FH, Hui E, Tse CY. The feeding paradox in advanced dementia: a local perspective. Hong Kong Med J 2017;23:306-10. Crossref

15. Luk JK, Chan WK, Ng WC, et al. Mortality and health services utilisation among older people with advanced cognitive impairment living in residential care homes. Hong Kong Med J 2013;19:518-24. Crossref

16. Chu LW. One step forward for advance directives in Hong Kong. Hong Kong Med J 2012;18:176-7.

17. Wong SY, Lo SH, Chan CH, Chui HS, Sze WK, Tung Y. Is it feasible to discuss an advance directive with a Chinese patient with advanced malignancy? A prospective cohort study. Hong Kong Med J 2012;18:178-85.

18. Ting FH, Mok E. Advance directives and life-sustaining treatment: attitudes of Hong Kong Chinese elders with chronic disease. Hong Kong Med J 2011;17:105-11.

19. Chu LW, Luk JK, Hui E, et al. Advance directive and end-of-life care preferences among Chinese nursing home residents in Hong Kong. J Am Med Dir Assoc 2011;12:143-52. Crossref