The maximum dose of atorvastatin and simvastatin as well as rosuvastatin should be restricted in East Asians

Hong Kong Med J 2024 Apr;30(2):184–5 | Epub 12 Apr 2024
https://doi.org/10.12809/hkmj2311348
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
The maximum dose of atorvastatin and simvastatin as well as rosuvastatin should be restricted in East Asians
Brian Tomlinson, MD, FHKAM (Medicine)1; Elaine Chow, MB, ChB, FHKAM (Medicine)2
1 Faculty of Medicine, Macau University of Science and Technology, Macau SAR, China
2 Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
 
Corresponding author: Prof Brian Tomlinson (btomlinson@must.edu.mo)
 
 Full paper in PDF
 
 
To the Editor—Statins are very safe medications when used in doses appropriate for the individual, but the letter from ML Tse highlights the risk of rhabdomyolysis with rosuvastatin 40 mg in Chinese patients.1 It was known at the time of first registration of rosuvastatin in 2003 that plasma levels were twice as high in East Asians (Chinese and Japanese) compared with Caucasians. As 40 mg is the maximum dose of rosuvastatin approved in Western countries, it would seem appropriate to restrict the maximum dose to 20 mg in East Asians. This has been adopted in China, Korea, and Japan.
 
Plasma levels of atorvastatin and simvastatin acid, the active form of simvastatin, are also higher in Chinese and Japanese subjects compared with Caucasians.2 The maximum dose of atorvastatin approved in Japan is 40 mg,3 and the 2023 Chinese guideline for lipid management contains the comment ‘Atorvastatin 80 mg is inexperienced in China, please use with caution’.4
 
The maximum approved or recommended daily dose of simvastatin is 20 mg in Japan and 40 mg in Korea and China. The Clinical Pharmacogenetics Implementation Consortium provides a guideline for genetic testing related to statin myopathy,5 and since 2012 they have recommended that the dose of simvastatin be restricted to 20 mg in individuals with the common c.521T>C variant (rs4149056) in the SLCO1B1 gene that encodes the OATP1B1 transporter. Considering this variant occurs in 11% to 16% of East Asians, it would seem wise to restrict the dose of simvastatin to 20 mg in the absence of genetic testing.
 
The Clinical Pharmacogenetics Implementation Consortium guideline applies to all ethnic groups. The relative risk of myopathy was 2.6 per copy of the SLCO1B1 521C variant in the Heart Protection Study with simvastatin 40 mg.6 The increased risk of myopathy in Chinese patients was seen in the HPS2-THRIVE trial (Heart Protection Study 2: Treatment of HDL to Reduce the Incidence of Vascular Events) where the combination of definite myopathy and incipient myopathy was about 10 times higher in China than in Europe (0.66% per year vs 0.07% per year; P<0.001) in participants taking simvastatin 40 mg in combination with extended-release niacin 2 g plus laropiprant 40 mg daily.7 This was probably due to an unexpected pharmacokinetic interaction between simvastatin and niacin.
 
In 2019, we reported the case of a 69-year-old Chinese male diabetic who had taken simvastatin 40 mg for 10 years and developed rhabdomyolysis, possibly related to unexpected drug interactions with Stevia rebaudiana and/or linagliptin.8 He was a carrier of one copy of SLCO1B1 521C and two copies of the C421>A variant of the adenosine triphosphate–binding cassette transporter G2 gene. That variant is more frequent in Chinese subjects. This illustrates that despite apparent long-term safe administration of simvastatin, it needs only an unpredicted drug-drug or herb-drug interaction or the gradual deterioration in renal function with age, which is more rapid in diabetics, to tip the balance and result in life-threatening toxicity in susceptible patients.
 
Author contributions
Both authors contributed to the concept or design, acquisition of data, analysis or interpretation of data, drafting of the letter, and critical revision of the letter for important intellectual content. Both authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
Both authors have disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Tse ML. Cluster of cases of high-dose rosuvastatin-associated rhabdomyolysis and recent reduction of rosuvastatin dose for Asians in other countries. Hong Kong Med J 2023;29:474. Crossref
2. Birmingham BK, Bujac SR, Elsby R, et al. Impact of ABCG2 and SLCO1B1 polymorphisms on pharmacokinetics of rosuvastatin, atorvastatin and simvastatin acid in Caucasian and Asian subjects: a class effect? Eur J Clin Pharmacol 2015;71:341-55. Crossref
3. Naito R, Miyauchi K, Daida H. Racial differences in the cholesterol-lowering effect of statin. J Atheroscler Thromb 2017;24:19-25. Crossref
4. Li JJ, Zhao SP, Zhao D, et al. 2023 Chinese guideline for lipid management. Front Pharmacol 2023;14:1190934. Crossref
5. Cooper-DeHoff RM, Niemi M, Ramsey LB, et al. The Clinical Pharmacogenetics Implementation Consortium guideline for SLCO1B1, ABCG2, and CYP2C9 genotypes and statin-associated musculoskeletal symptoms. Clin Pharmacol Ther 2022;111:1007-21. Crossref
6. SEARCH Collaborative Group; Link E, Parish S, et al. SLCO1B1 variants and statin-induced myopathy—a genomewide study. N Engl J Med 2008;359:789-99. Crossref
7. HPS2-THRIVE Collaborative Group. HPS2-THRIVE randomized placebo-controlled trial in 25 673 high-risk patients of ER niacin/laropiprant: trial design, pre-specified muscle and liver outcomes, and reasons for stopping study treatment. Eur Heart J 2013;34:1279-91. Crossref
8. Chan JC, Ng MH, Wong RS, Tomlinson B. A case of simvastatin-induced myopathy with SLCO1B1 genetic predisposition and co-ingestion of linagliptin and Stevia rebaudiana. J Clin Pharm Ther 2019;44:381-3. Crossref

Prioritising the psychosocial needs of young oncology patients: a call for comprehensive care

Hong Kong Med J 2024 Apr;30(2):186 | Epub 10 Apr 2024
https://doi.org/10.12809/hkmj2311405
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Prioritising the psychosocial needs of young oncology patients: a call for comprehensive care
CY Wong, FHKCP1; HY Au, FHKCP1; KY Chan, MD, FHKCP1; Harinder Gill, MD, FRCP2
1 Palliative Medical Unit, Grantham Hospital, Hong Kong SAR, China
2 Department of Medicine, The University of Hong Kong, Hong Kong SAR, China
 
Corresponding author: Dr CY Wong (ashleywcy@gmail.com)
 
 Full paper in PDF
 
 
To the Editor—We write in response to an article published in November 2023 on digital media that discussed the difficulties faced by local young cancer patients who are receiving oncology treatment.1 We would like to highlight the importance of addressing these challenges and propose solutions to help overcome them.
 
In 2021, young oncology patients comprised up to 4.1% of all cancer cases in Hong Kong.2 They experience a range of emotional, social, and financial challenges that greatly impact their overall well-being. Neglecting their needs not only strains their relationship with family, but also hampers their ability to effectively cope with the disease. The financial toxicity of cancer treatment, which includes the expenses, indirect costs and lost income associated with cancer treatment, further exacerbates these challenges.3 4
 
To address these issues effectively it is essential to provide services specifically designed for young cancer patients according to their stage of development. They are at high risk of psychosocial problems and should be prioritised for early integration into palliative care services to improve their quality of life and that of their family.5 Mental health professionals and support groups should be widely available for psychological support. Some medical allowances and social services are provided only for the older adults. Medical-social collaboration and educational resources could improve access by young adults to community support. Additionally, implementing targeted financial assistance programmes and providing employment support will help alleviate the financial burden. It is crucial to recognise and address the obstacles faced by young cancer patients.
 
Author contributions
All authors contributed to the concept or design, acquisition of data, or interpretation of data, drafting of the letter, and critical revision of the letter for important intellectual content. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
All authors have disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. HK01. Hong Kong young cancer patients established a mutual aid platform to help themselves as existing cancer support is mostly targeted at the middle-aged and older adults. [in Chinese]. 2023 November 22. Available from: https://www.hk01.com/article/957641?utm_source=01appshare&utm_medium=referral. Accessed 26 Nov 2023.
2. Hong Kong Cancer Registry, Hospital Authority, Hong Kong SAR Government. Overview of Hong Kong Cancer Statistics of 2021. Available from: https://www3.ha.org.hk/cancereg/default.asp. Accessed 28 Nov 2023.
3. Evan EE, Zeltzer LK. Psychosocial dimensions of cancer in adolescents and young adults. Cancer 2006;107(7 Suppl):1663-71. Crossref
4. Geue K, Götze H, Friedrich M, et al. Perceived social support and associations with health-related quality of life in young versus older adult patients with haematological malignancies. Health Qual Life Outcomes 2019;17:145. Crossref
5. Zimmermann C, Swami N, Krzyzanowska M, et al. Early palliative care for patients with advanced cancer: a cluster-randomised controlled trial. Lancet 2014;383:1721-30. Crossref

Specialised crew resource management programme for non–locally trained healthcare professionals: expediting healthcare cultural adaptation

Hong Kong Med J 2024 Feb;30(1):80–1 | Epub 1 Feb 2024
https://doi.org/10.12809/hkmj2311287
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Specialised crew resource management programme for non–locally trained healthcare professionals: expediting healthcare cultural adaptation
Eric HK So, MB, BS, FHKAM (Anaesthesiology),1,2; Victor KL Cheung, MSc (OP), RegPsychol (HKPS)1; Avis SH Leung, MSSc, RN1; SS So, MSc, BBA1; Jeff LK Hung, MSc, BSSc1; Terry ML Yau, MBA, SNM3; NH Chia, MB, BS, FRCSEd (Gen)1,4; George WY Ng, MB, BS, FCICM1,5
1 Multi-Disciplinary Simulation and Skills Centre, Queen Elizabeth Hospital, Hong Kong SAR, China
2 Department of Anaesthesiology and Operating Theatre Services, Queen Elizabeth Hospital, Hong Kong SAR, China
3 Central Nursing Division, Kowloon Central Cluster, Hospital Authority, Hong Kong SAR, China
4 Department of Surgery, Queen Elizabeth Hospital, Hong Kong SAR, China
5 Intensive Care Unit, Queen Elizabeth Hospital, Hong Kong SAR, China
 
Corresponding author: Dr Eric HK So (sohke@ha.org.hk)
 
 Full paper in PDF
 
 
To the Editor—Healthcare delivery is one of the most complex sociotechnical processes with healthcare practitioners working under adverse and stressful conditions despite being adequately trained for medical-technical proficiency. Human factors contribute to 70% to 80% of medical incidents.1 The focus has shifted gradually from individual competence to teamwork as a prerequisite to improve patient safety.1 2
 
Teamwork skills training, crew resource management (CRM), has become an essential and integral part of a corporate-wide teamwork training programme in the Hong Kong Hospital Authority.1 Applying CRM can transform a team of highly specialised experts into an expert team for safe patient care, good working climate and team member satisfaction.1
 
In April 2023, the Hospital Authority launched its first Greater Bay Area (GBA) Healthcare Talents Visiting Programme.1 In September 2023, a Multi-Disciplinary Simulation and Skills Centre at Queen Elizabeth Hospital and the Central Nursing Division co-organised a 4-hour classroom-based interactive group sharing programme for 14 non–locally trained professionals in the Kowloon Central Cluster (Table).3 4 The elements covered in the Cluster’s CRM training include assertiveness, communication, leadership and followership (interpersonal skills), and situational awareness (cognitive skills).
 

Table. Curriculum of crew resource management (CRM) sharing programme for non–locally trained healthcare professionals (4 doctors, 10 nurses) from the Greater Bay Area
 
This pilot programme, titled ‘Sharing Activity for Non–Locally Trained Healthcare Professionals’ (深化醫療團隊協作), aimed to broaden participants’ awareness of the Hospital Authority organisational structure and training centre development and share elements of standard Kowloon Central Cluster CRM training. The objective was improved better clinical teamwork and adaptation among interdisciplinary professionals from diverse training backgrounds.1 5
 
We conducted an evaluation before and after this pilot programme. All items on pre- and post-questionnaires used a 5-point Likert scale (1=Strongly disagree, 2=Disagree, 3=Neutral, 4=Agree, 5=Strongly agree). Our evaluation identified a remarkable increase in understanding of the local healthcare service (score range of the results of items in this category=3.79-4.90; overall increase in knowledge from pre-test to post-test in this category=23%) and elements of CRM (score range of the results of items in this category=4.19-5; overall increase in knowledge from pre-test to post-test in this category=20%). All participants (n=14, 100%) found acquisition of CRM could improve patient safety and 93% (n=13) were confident that they could apply the principles in clinical practice. From the perspective of personal interests and clinical benefits, participants placed a high value on all content but especially ‘Concept of CRM’ (mean ± standard deviation=4.93 ± 0.27) and ‘Simulation technology applied in training and research’ (mean=5). A Self-Evaluated Behaviour Assessment (SEBA-28) addressed the overall impact of the programme on participants’ attitude towards CRM-related behaviours (+10%), in particular ‘Situational awareness’ (+14%).5 When identifying challenges in healthcare cultural adaptation, 93% of participants (n=13) were optimistic that implementing the concept of CRM would mitigate challenges regarding communication, interdisciplinary team cooperation, and cultural diversity.
 
The evaluation demonstrates the potential and value of a CRM programme for non–locally trained healthcare professionals. Various Hospital Authority training centres could play an important role to facilitate integration and interaction of team members from diverse training backgrounds through CRM training. Further study should be planned to fill the knowledge and research gaps and build resilient expert teams in the Hospital Authority.
 
Author contributions
All authors contributed to the concept or design of the letter, acquisition of data, and analysis or interpretation of data. EHK So and VKL Cheung drafted the letter. All authors critically revised the letter for important intellectual content. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
All authors have disclosed no conflicts of interest.
 
Acknowledgement
The authors express their gratitude to the Hospital Authority Head Office Medical Grade and the hospital management of the Kowloon Central Cluster for their support and contribution to the Crew Resource Management programme specialised for non–locally trained healthcare professionals from the Greater Bay Area.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Chan CK, So EH, Ng GW, Ma TW, Chan KK, Ho LY. Participant evaluation of simulation training using crew resource management in a hospital setting in Hong Kong. Hong Kong Med J 2016;22:131-7. Crossref
2. Hospital Authority. HASLink: strengthen exchange with Greater Bay Area. November 2022. Available from: https://www3.ha.org.hk/ehaslink/issue122/en/feature-1.html. Accessed 5 Sep 2023.
3. So EH, Chia NH, Ng GW, et al. Multidisciplinary simulation training for endotracheal intubation during COVID-19 in one Hong Kong regional hospital: strengthening of existing procedures and preparedness. BMJ Simul Technol Enhanc Learn 2021;7:501-9. Crossref
4. Cheung VK, Chia NH, So SS, Ng GW, So EH. Expanding scope of Kirkpatrick model from training effectiveness review to evidence-informed prioritization management for cricothyroidotomy simulation. Heliyon 2023;9:e18268. Crossref
5. Leung AS, So EH, Chan CN, et al. Embracing human factors in assertiveness, communication, leadership and followership, and situational awareness through O&G specific CRM classroom training. Presented at: KCC Convention; 26 November 2021; Hong Kong SAR, China.

Survival of out-of-hospital cardiac arrest following a return of spontaneous circulation beyond 30 minutes

Hong Kong Med J 2023 Dec;29(6):564–5 | Epub 23 Aug 2023
https://doi.org/10.12809/hkmj219365
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Survival of out-of-hospital cardiac arrest following a return of spontaneous circulation beyond 30 minutes
KL Hon, MB, BS, MD1; Karen KY Leung, MB, BS, MRCPCH1; KL Chan, MB, ChB, MRCPCH1; WF Hui, MB, ChB, MRCPCH1; KT Chau, MB, BS, FRCPCH1; SY Qian, MD2
1 Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong SAR, China
2 Pediatric Intensive Care Unit, Beijing Children’s Hospital, Capital Medical University, Beijing, China
 
Corresponding author: Dr KL Hon (ehon@hotmail.com)
 
 Full paper in PDF
 
 
To the Editor—There was a local blog report in Hong Kong of a 5-year-old girl who experienced out-of-hospital cardiac arrest (OHCA) with return of spontaneous circulation (ROSC) after 31 minutes and was discharged with an implantable cardioverter defibrillator.1 However, ROSC within 30 minutes is usually required for a favourable outcome.2 3
 
We performed a literature search to determine the longest time to ROSC and survival rates of OHCA in children (Table). Out-of-hospital cardiac arrest in children has a poor prognosis and prolonged in-hospital resuscitation beyond 30 minutes does not improve survival.3 Predictors of survival to discharge include witnessed arrest (P=0.012), delivery of bystander cardiopulmonary resuscitation (P=0.003), and duration of resuscitation (P=0.028). However, none who received more than 30 minutes of in-hospital resuscitation survived.4 A prospective study found that no patients who required >2 doses of adrenaline or in-hospital resuscitation for longer than 20 minutes survived to discharge.5 However, it is possible that ROSC beyond 30 minutes has not been reported, or that this case is an exception.
 

Table. Selective paediatric references on out-of-hospital cardiac arrest following return of spontaneous circulation
 
Evidence suggests that either death or a poor outcome is inevitable if OHCA occurs more than 30 minutes from the nearest healthcare facility or the resuscitation exceeds 30 minutes.6 7 A 2017 study reported that the survival rate to discharge in Hong Kong was only 2.3%, which was considerably lower than the global survival rate in adults (8.8%).8 9 As OHCA in children has not been evaluated in Hong Kong until 2018,3 and prospective evaluation of OHCA in children has not yet been conducted, we concur with Wu10 who suggested the establishment of an OHCA registry.
 
Many parents and family members who are present during a resuscitation attempt would want to be in attendance if their child were likely to die, and this experience can help with later grieving without impacting on the resuscitation process. If appropriate, family-centred care should be practised and parents should be involved in the decision-making process.6 As paediatricians, although our patient is the child, his/her family members are also important—after all, if the child passes away, it is the family who must shoulder the lifelong emotional burden.
 
In summary, OHCA in children has a poor prognosis and prolonged resuscitation does not improve survival or outcome.
 
Author contributions
All authors contributed to the drafting of the letter and critical revision for important intellectual content. All authors approved the final version for publication and take responsibility for its accuracy and integrity.
 
Conflicts of interest
As an editor of the journal, KL Hon was not involved in the peer review process. Other authors have disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Philip. 死去31分鐘的女兒 [in Chinese]. Available from: https://todecidenow.wordpress.com/2021/01/31/死去31分鐘的女兒！/. Accessed 24 Jul 2023.
2. Hon KL, Tse TT, Au CC, et al. Brain death in children: a retrospective review of patients at a paediatric intensive care unit. Hong Kong Med J 2020;26:120-6. Crossref
3. Law AK, Ng MH, Hon KL, Graham CA. Out-of-hospital cardiac arrest in the pediatric population in Hong Kong: a 10-year review at a university hospital. Pediatr Emerg Care 2018;34:179-84. Crossref
4. Tham LP, Chan I. Paediatric out-of-hospital cardiac arrests: epidemiology and outcome. Singapore Med J 2005;46:289-96.
5. Schindler MB, Bohn D, Cox PN, et al. Outcome of out-of-hospital cardiac or respiratory arrest in children. N Engl J Med 1996;335:1473-9. Crossref
6. American College of Surgeons Committee on Trauma; American College of Emergency Physicians Pediatric Emergency Medicine Committee; National Association of EMS Physicians; American Academy of Pediatrics Committee on Pediatric Emergency Medicine; Fallat ME. Withholding or termination of resuscitation in pediatric out-of-hospital traumatic cardiopulmonary arrest. Pediatrics 2014;133:e1104-16. Crossref
7. American Heart Association. Highlights of the 2020 American Heart Association Guidelines for CPR and ECC. 2020. Available from: https://cpr.heart.org/-/media/cpr-files/cpr-guidelines-files/highlights/hghlghts_2020_ecc_guidelines_english.pdf. Accessed 3 Apr 2021.
8. 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
9. Yan S, Gan Y, Jiang N, et al. The global survival rate among adult out-of-hospital cardiac arrest patients who received cardiopulmonary resuscitation: a systematic review and meta-analysis. Crit Care 2020;24:61. Crossref
10. Wu WY. Out-of-hospital cardiac arrest: the importance of a registry. Hong Kong Med J 2019;25:176-7. Crossref

A concerning trend of synthetic cathinone abuse in Hong Kong

Hong Kong Med J 2023 Dec;29(6):563 | Epub 9 Nov 2023
https://doi.org/10.12809/hkmj2310966
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
A concerning trend of synthetic cathinone abuse in Hong Kong
HS Leung, MB, BS1,2; Magdalene HY Tang, PhD1,2; HF Tong, FHKCPath, FHKAM (Pathology)1,2; YK Chong, FHKCPath, FHKAM (Pathology)1,2
1 Hospital Authority Toxicology Reference Laboratory, Hong Kong SAR, China
2 Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China
 
Corresponding author: Dr YK Chong (cyk280a@ha.org.hk)
 
 Full paper in PDF
 
 
To the Editor—Synthetic cathinones constitute a class of new psychoactive substances that are derivatives of cathinone, a naturally occurring compound in the khat plant with stimulant properties.1 Historically, our laboratory has encountered a limited number of synthetic cathinone cases. From 2009 to 2017, we identified only seven instances.2 Subsequently, an additional six cases were recorded between 2018 and 2022 (unpublished data, 2022). However, in the first half of 2023 alone, we have identified eight additional cases, seven of which involved intoxication with N,N-dimethylpentylone.
 
Since its identification in toxicology samples in the United States in 2021, the abuse of N,N-dimethylpentylone has become increasingly prevalent.3 This substance has also been detected in New Zealand and Spain through on-site pill testing, analysis of seized materials, and wastewater-based epidemiological investigations.4 The use and abuse of synthetic cathinones can result in a sympathomimetic toxidrome characterised by agitation, tachycardia, hyperthermia, convulsions, rhabdomyolysis, cardiovascular collapse, and ventricular arrhythmias. N,N-dimethylpentylone has been identified in at least 18 post-mortem forensic toxicology cases.5
 
N,N-dimethylpentylone has been sold as 3,4-methylenedioxymethamphetamine (MDMA; commonly known as ecstasy). In our experience, co-ingestion of N,N-dimethylpentylone and MDMA is common. Considering the potential morbidity and mortality associated with N,N-dimethylpentylone, the medical profession must remain vigilant in monitoring and describing the toxicological profile of the compound. Importantly, traditional toxicology analyses are often unable to detect new psychoactive substances; specific detection methods are required. When clinicians encounter a suspicious clinical history or unfamiliar/unusually severe clinical toxidromes, they are encouraged to utilise the services provided by our laboratory, including target analyses by liquid chromatography–tandem mass spectrometry.
 
Author contributions
All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
All authors have disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Paillet-Loilier M, Cesbron A, Le Boisselier R, Bourgine J, Debruyne D. Emerging drugs of abuse: current perspectives on substituted cathinones. Subst Abuse Rehabil 2014;5:37-52. Crossref
2. Tang MH, Hung LY, Lai CK, Ching CK, Mak TW. 9-year review of new psychoactive substance use in Hong Kong: a clinical laboratory perspective. HK J Emerg Med 2019;26:179-85. Crossref
3. Walton S, Fogarty M, Papsun D, Lamb M, Logan B, Krotulski A. N,N-dimethylpentylone—an emerging NPS stimulant of concern in the United States. Toxicol Analy et Clin 2022;34:S67-8. Crossref
4. Rousis N, Bade R, Romero-Sánchez I, et al. Festivals following the easing of COVID-19 restrictions: prevalence of new psychoactive substances and illicit drugs. Environ Int 2023;178:108075. Crossref
5. Fogarty MF, Krotulski AJ, Papsun DM, et al. N,N-dimethylpentylone (dipentylone)—a new synthetic cathinone identified in a postmortem forensic toxicology case series. J Anal Toxicol 2023;47:753-61. Crossref

Cluster of cases of high-dose rosuvastatin–associated rhabdomyolysis and recent reduction of rosuvastatin dose for Asians in other countries

Hong Kong Med J 2023 Oct;29(5):474 | Epub 28 Sep 2023
https://doi.org/10.12809/hkmj2310943
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Cluster of cases of high-dose rosuvastatin–associated rhabdomyolysis and recent reduction of rosuvastatin dose for Asians in other countries
ML Tse, FHKAM (Emergency Medicine)
Hong Kong Poison Information Centre, Hospital Authority, Hong Kong SAR, China
 
Corresponding author: Dr ML Tse (tseml@ha.org.hk)
 
 Full paper in PDF
 
 
To the Editor—From July 2022 to April 2023, the Hong Kong Poison Information Centre has recorded six cases of severe rhabdomyolysis associated with prescription of high-dose rosuvastatin (≥40 mg daily). All patients were Chinese and presented with a mean creatine kinase concentration of approximately 15 000 IU/L. All except one patient developed acute kidney injury and three required temporary renal replacement therapy. Concomitant liver injury was also evident in three patients. Although statin treatment is associated with development of rhabdomyolysis, the reported incidence is rare at 0.44 per 10 000 person-years.1 Nonetheless Asian patients possess pharmacogenetic factors placing them at high risk. It has been reported that Chinese subjects had a plasma rosuvastatin level 2.3 times that of white subjects, despite being prescribed the same dose.2 Other risk factors include advanced age, hypothyroidism, alcohol abuse, poor renal function, vitamin D deficiency, diabetes mellitus, and drug-drug interactions. The recent clustering of six cases raised concerns about the safety of high-dose rosuvastatin in the Hong Kong population.
 
In mainland China, the recommended maximum daily dose of rosuvastatin is only 20 mg. It should also be noted that when product inserts of Crestor (rosuvastatin calcium) were revised in 2022 in the United Kingdom,3 Australia4 and Canada,5 Asian ethnicity was a contraindication for prescription of Crestor 40 mg per day. Both prescribers and pharmacists should be aware of this change and doctors should be warned of the increased vulnerability of Chinese and other Asian patients. The licenced dose of rosuvastatin in Hong Kong may need to be revised urgently.
 
Author contributions
The author had full access to the data, contributed to the study, approved the final version for publication, and takes responsibility for its accuracy and integrity.
 
Conflicts of interest
The author has disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Graham DJ, Staffa JA, Shatin D, et al. Incidence of hospitalized rhabdomyolysis in patients treated with lipid-lowering drugs. JAMA 2004;292:2585-90. Crossref
2. Lee E, Ryan S, Birmingham B, et al. Rosuvastatin pharmacokinetics and pharmacogenetics in white and Asian subjects residing in the same environment. Clin Pharmacol Ther 2005;78:330-41. Crossref
3. Crestor film-coated tablets (package insert). London: AstraZeneca UK Ltd; 2022.
4. Crestor (rosuvastatin calcium) film-coated tablets (package insert). Chatswood: Menarini Australia Pty Ltd; 2022.
5. Crestor (rosuvastatin calcium tablets) [package insert]. Mississauga: AstraZeneca Canada Inc; 2022.

COVID-19: evidence for 2-week versus 3-week quarantine

Hong Kong Med J 2023 Jun;29(3):273–4
https://doi.org/10.12809/hkmj209254
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
COVID-19: evidence for 2-week versus 3-week quarantine
KL Hon, MB, BS, MD1,2; Karen KY Leung, MB, BS, MRCPCH1; Maggie Wang, PhD3; S Zhao, PhD3
1 Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong SAR, China
2 Department of Paediatrics, CUHK Medical Centre, The Chinese University of Hong Kong, Hong Kong SAR, China
3 The Jockey Club School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
 
Corresponding author: Dr KL Hon (ehon@hotmail.com)
 
 Full paper in PDF
 
To the Editor—A new variant of coronavirus disease 2019 (COVID-19, SARS-CoV-2 VUI 202012/01) was identified in the United Kingdom before Christmas 2020. Preliminary reports suggested that this variant was up to 70% more transmissible compared with previous strains in circulation.1 In response, large parts of London and South East England introduced the strictest Tier 4 restrictions, where all residents were asked to remain at home, all non-essential shops closed and Christmas celebrations cancelled for many families in the country.2 This new variant had already been identified in other countries across Europe and beyond (including Australia, Japan and Canada).1 3 The Hong Kong SAR Government swiftly responded by escalating quarantine requirements for inbound travellers from 14 to 21 days, one of the strictest quarantine policies around the world (Table 1 4 5 6 7). It is important to examine the scientific evidence for the effectiveness of quarantine practices to reassure citizens, government officials, and law enforcing personnel.
 

Table 1. Coronavirus disease 2019 (COVID-19) quarantine duration and COVID-19 testing policies of different places
 
To compare the effectiveness of various quarantine protocols, a study focusing on infected individuals and the probability of ‘missing’ such cases under each protocol based on the evidence available has been conducted (Table 2).8 Serial testing on days 7 and 14 appeared to be the most effective with 91% of infected individuals identified. On the contrary, the yield was unsatisfactory for serial testing on days 1 and 14 or 21 with a substantial proportion of positive cases missed (43% and 67%, respectively).
 

Table 2. Theoretical infected cases missed8
 
Nonetheless the likelihood of COVID-19 transmission is not evenly distributed along the timeline post infection. By applying the known epidemiological characteristics of COVID-19 transmission (ie, transmission follows a gamma distribution with mean=5.3 days, standard deviation=2.1 days, and basic reproduction number=2.5), we can infer the effectiveness of different quarantine durations. For example, an infected individual who has two serially negative reverse transcription polymerase chain reaction (RT-PCR) tests 1 week apart who is released on day 7 post-infection would cause infection in around 0.092 secondary cases (2.5×19%×19.3%). In a second scenario, an infected person with two serially negative RT-PCR tests 2 weeks apart who is released on day 14 post-infection would lead to 0.001 secondary cases (2.5×43%×0.1%). In a third scenario that reflects the latest quarantine changes, an infected individual with two serially negative RT-PCR tests 3 weeks apart and who is released on day 21 post-infection would lead to approximately 0.000 secondary cases (2.5×67%×0.0%). Clearly, the largest reduction in risk of secondary cases due to imported seed cases can be achieved through the 2-week policy rather than a 1-week policy of isolation (99% reduction in risk of secondary cases).
 
Based on this evidence, it can be concluded that a protocol of 2 weeks quarantine, not 3, will miss one infected person for every 1000 infected persons. Over 8000 reported cases (8425) have been identified in Hong Kong to date and the majority were not quarantined at the time of writing in early 2021. If we apply the policy of quarantine for 2 weeks with two serial tests, we would have missed eight infected individuals who would have been identified over the last 12 months had they been quarantined for 21 days.
 
Based on scientific evidence, the policy of 3-week quarantine can potentially reduce the risk of introducing this new highly contagious variant. This strict quarantine policy will come with a very high economic cost, but was considered as essential to protect the lives of Hong Kong citizens during the middle of the COVID-19 pandemic in December 2020. In hindsight, our observation provides important information to guide quarantine policy about emerging respiratory viral infections with similar infectivity, basic (and initial) reproduction number R0 (R-naught), and the current reproduction number Rt (R at time t).
 
Author contributions
All authors contributed to the concept or design, acquisition of data, analysis or interpretation of data, drafting of the manuscript, and critical revision of the manuscript for important intellectual content. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
As an editor of the journal, KL Hon was not involved in the peer review process. Other authors have no conflicts of interest to disclose.
 
Funding/support
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. World Health Organization. SARS-CoV-2 Variant–United Kingdom of Great Britain and Northern Ireland. 2020. Available from: https://www.who.int/emergencies/disease-outbreak-news/item/2020-DON304. Accessed 28 Dec 2020.
2. ABC News. London to go into strictest restrictions as new variant of COVID-19 identified. Available from: https://www.abc.net.au/news/2020-12-15/london-to-get-into-strictest-restrictions-highest-covid-rate/12973596. Accessed 28 Dec 2020.
3. BBC News. Coronavirus: cases of new variant appear worldwide. Available from: https://www.bbc.com/news/world-europe-55452262. Accessed 28 Dec 2020.
4. Hong Kong SAR Government. Quarantine for inbound travellers–frequently asked questions. Available from: https://www.coronavirus.gov.hk/eng/inbound-travel-faq.html#FAQ7. Accessed 28 Dec 2020.
5. United Kingdom Government. Entering the UK. 2020. Available from: https://www.gov.uk/uk-border-control/ending-self-isolation-early-through-test-to-release. Accessed 27 Dec 2020.
6. Government of Canada. Travel restrictions in Canada. Mandatory isolation or quarantine. Available from: https://travel.gc.ca/travel-covid/travel-restrictions/isolation. Accessed 27 Dec 2020.
7. Department of Health, Australian Government. Coronavirus (COVID-19) advice for international travellers. Available from: https://www.health.gov.au/news/health-alerts/novel-coronavirus-2019-ncov-health-alert/coronavirus-covid-19-restrictions/coronavirus-covid-19-advice-for-international-travellers. Accessed 27 Dec 2020.
8. Kucirka LM, Lauer SA, Laeyendecker O, Boon D, Lessler J. Variation in false-negative rate of reverse transcriptase polymerase chain reaction–based SARS-CoV-2 tests by time since exposure. Ann Intern Med 2020;173:262-7. Crossref

COVID-19 in a centenarian, the vaccination, the breakthrough infection, and the third booster dose

Hong Kong Med J 2023 Apr;29(2):181 | Epub 14 Apr 2023
https://doi.org/10.12809/hkmj2210400
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
COVID-19 in a centenarian, the vaccination, the breakthrough infection, and the third booster dose
John SM Leung, MB, BS, FHKAM (Surgery)
Cardiothoracic Surgical Unit, St Paul’s Hospital, Hong Kong SAR, China
 
Corresponding author: Dr John SM Leung (leungjohnsiuman@gmail.com)
 
 Full paper in PDF
 
 
To the Editor—Dr Ellen Tam and her Tuen Mun Hospital colleagues contributed an important study of coronavirus disease 2019 (COVID-19) infection among the older adults1 who are an increasingly large population in Hong Kong. Of particular interest is the higher mortality associated with increasing frailty but not necessarily increasing age. The latter seems to level off after age 90. May I substantiate this observation with the case of a centenarian who was fully vaccinated with two doses of Comirnaty and survived a breakthrough COVID-19 infection before proceeding to receive a third booster vaccination.
 
A female patient born in December 1920 had vascular dementia that had progressed over 15 years to a level at which she was completely dependent on a carer. She also had recurrent urinary and respiratory tract infections, osteoporosis and persistent bed sores. Echocardiogram revealed concentric left ventricular hypertrophy and diastolic dysfunction. Her clinical frailty score had been >7 for the last 10 years.
 
Two doses of Comirnaty were administered on the patient on 19 July and 22 August 2021, respectively. On 8 March 2022, while waiting for her third dose (booster), her whole family became infected with COVID-19 (tested positive by rapid antigen test) and developed cough and fever. The patient remained asymptomatic with no fever, cough, shortness of breath or loss of appetite. Family members recovered spontaneously and the patient remained negative on rapid antigen test from 12 March 2022 onwards. The third dose of Comirnaty was given to the patient after a delay of 4 months on 1 July 2022 and was well tolerated. Her severe acute respiratory syndrome coronavirus 2 nucleocapsid and envelope protein antibody titre was >2500 units/μL, well above the measuring capacity of our laboratory equipment.
 
This case shows how a centenarian with poor clinical frailty score was well protected against symptomatic COVID-19 infection during the height of the most severe wave of infection. Her antibody response after the third dose of Comirnaty was proven to be very high. We do not regularly test antibody level at a population level following vaccination but the level of protection can be seen from data in the official records (Table 2). Although older adults aged over 80 accounted for the great majority of COVID-19 deaths, those who received three doses of vaccine remained well protected with a mortality rate of ≤1%.2 Had this age-group been fully vaccinated, their mortality would have been reduced from 6542 to around 65.
 

Table. Mortality percentage and number of deaths by age-group and number of doses of the coronavirus disease 2019 (COVID-19) vaccine received in the fifth wave of COVID-192
 
Kordowitzki3 produced a report of COVID-19 infection in centenarians across various countries. Mortality rate of COVID-19 appeared to peak among octogenarians, as in this Hong Kong study, and showed some decline among those in their 90s. Although there are scanty reports of centenarian survival from COVID-19 infection from China, Germany and France, there has been little mention of the protection afforded by vaccination in this age-group. Genetic and acquired immune factors that favour extreme longevity might also favour immunity against COVID-19 infection.3
 
I hope the experience of this patient might be of interest to health workers dealing with the oldest section of our population, particularly in overcoming their vaccine hesitancy.
 
Author contributions
The author contributed to the drafting of the letter and critical revision for important intellectual content. The author approved the final version for publication and takes responsibility for its accuracy and integrity.
 
Conflicts of interest
The author declared no conflict of interest.
 
References
1. Tam EM, Kwan YK, Ng YY, Yam PW. Clinical course and mortality in older patients with COVID-19: a clusterbased study in Hong Kong. Hong Kong Med J 2022;28:215-22 Crossref
2. Hong Kong SAR Government. Archive of statistics on 5th wave of COVID-19. Available from: https://www.coronavirus.gov.hk/eng/5th-wave-statistics.html#. Accessed 20 Jul 2022.
3. Kordowitzki P. Centenarians and COVID-19: is there a link between longevity and better immune defense? Gerontology 2022;68:556-7. Crossref

Better preparation for intubation

Hong Kong Med J 2023 Apr;29(2):178–80 | Epub 12 Apr 2023
https://doi.org/10.12809/hkmj2210571
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTERS TO THE EDITOR
Better preparation for intubation
Daniel KK Ng, MB, BS, MD1; Cynthia Cheung2; WY Wu, MNurs3
1 Department of Paediatrics, Hong Kong Sanatorium & Hospital, Hong Kong SAR, China
2 Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong SAR, China
3 Research Department, Hong Kong Sanatorium & Hospital, Hong Kong SAR, China
 
Corresponding author: Dr Daniel KK Ng (daniel.kk.ng@hksh.com)
 
 Full paper in PDF
 
To the Editor—We read with interest the article by Cheng et al1 who reported a child with peritonsillar abscess and impending airway obstruction who underwent two failed attempts at intubation with consequent rapid desaturation down to an oxygen saturation (SpO2) level of 50% to 60%, requiring insertion of a laryngeal mask to maintain ventilation before successful intubation. In the same issue, a standard protocol for intubation was suggested by Leung et al.2 They describe the rescue plan for intubation, alluding to the need for pre-oxygenation for 3 to 5 minutes prior to rapid sequence induction. These articles highlight the need to increase the arterial oxygen reserve to avoid rapid desaturation with all its dire consequences.
 
We would like to remind readers about a recent technological development that enables measurement and monitoring of the oxygen reserve index (ORI), the increase in arterial oxygen pressure (PaO2) in real time. As shown by the oxygen dissociation curve, desaturation would be delayed if PaO2 could be increased from 100 mmHg to say 200 mmHg.3 Oxygen reserve index is a proprietary technology available using the Masimo pulse oximeter with a range from 0 to 1. When SpO2 reaches 100%, any further increase is reflected in the ORI that will rise above 0. We suggest that attending doctors pre-oxygenate to an ORI well above 0 to achieve a greater oxygen reserve and prevent the rapid desaturation reported by Cheng et al.1 We also suggest provision of pre-oxygenation via heated humidified high-flow (HHHF) oxygen with fraction of inspired oxygen (FiO2) up to 1. Nonetheless, the other end of the spectrum to hypoxaemia is hyperoxia, less obviously harmful but still to be avoided with excessive oxygenation leading to atelectasis.4 5 To prevent severe hyperoxia, ORI should be maintained at around 0.5. Monitoring the ORI and titrating FiO2 such that the ORI is maintained above 0 may help prevent both a hypoxic state during intubation and hyperoxia. During intubation, ORI should also be continuously monitored along with SpO2 since it can predict a decline in SpO2.
 
Pre-oxygenation by HHHF followed by continuous HHHF during intubation is also beneficial, even in the presence of paralysis that occurs during rapid sequence induction. Continuous removal of oxygen by red blood cells flowing through the capillaries abutting the alveoli leads to a negative pressure that draws in air from the atmosphere only if the whole airway is patent. This phenomenon is called apnoea oxygenation.6 Nonetheless classic apnoeic oxygenation in the absence of high flow provides little clearance of carbon dioxide and may lead to progressive respiratory acidosis. The impact of adding high flow on CO2 clearance is controversial, with CO2 rising at a much lower rate of 0.15 kPa/min in adults6 compared with only classic apnoeic oxygenation and a reported rate of 0.45 kPa/min.7 Nonetheless CO2 clearance is reported to be lower in children at 0.32 kPa/min.8 In a single case report, the end-tidal CO2 was reported to be only 9.1 kPa at the end of apnoea of 46 minutes, much lower than the expected rise to >10 kPa in the absence of ventilation.9 Fortunately, PaCO2 up to 13.3 kPa is not reported to be associated with adverse outcome.10 Continuing HHHF during intubation not only facilitates oxygenation, but it also potentially improves CO2 clearance by flushing of the dead space, hence lowering the risk of CO2 toxicity.6 Since HHHF can be administered during intubation without obstructing the procedure, its use should be continued during the intubation process.
 
Leung et al2 also mentioned cricoid pressure as an essential step in rapid sequence induction although recent evidence has cast doubt on its effectiveness in preventing aspiration and the potential distortion of anatomy making intubation more difficult.11 We suggest that cricoid pressure be applied only if deemed essential by the attending team. It should not be performed routinely during rapid sequence induction.
 
In conclusion, administration of HHHF with enriched oxygen should be incorporated into the standard protocol for pre-oxygenation and used continuously during intubation. Oxygen reserve index should be continuously monitored to achieve mild hyperoxia to prevent rapid desaturation by a timely increase of FiO2 or flow or chin lift/jaw thrust to establish upper airway patency. This index is also useful to avoid severe hyperoxia and consequent atelectasis.
 
Author contributions
All authors contributed to the drafting of the letter and critical revision for important intellectual content. All authors approved the final version for publication and take responsibility for its accuracy and integrity.
 
Conflicts of interest
The authors have no conflicts of interest to disclose.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
References
1. Cheng GC, Wong JW. Managing limitations of the LMA Classic laryngeal mask as a conduit for tracheal intubation in impending paediatric airway obstruction: a case report. Hong Kong Med J 2022;28:321-3. Crossref
2. Leung KK, Ku SW, Fung RC, et al. Airway management in children with COVID-19. Hong Kong Med J 2022;28:315-20. Crossref
3. Scheeren TW, Belda FJ, Perel A. The oxygen reserve index (ORI): a new tool to monitor oxygen therapy. J Clin Monit Comput 2018;32:379-89. Crossref
4. Koo CH, Park EY, Lee SY, Ryu JH. The effects of intraoperative inspired oxygen fraction on postoperative pulmonary parameters in patients with general anaesthesia: a systemic review and meta-analysis. J Clin Med 2019;8:583. Crossref
5. Staehr-Rye AK, Meyhoff CS, Scheffenbichler FT, et al. High intraoperative inspiratory oxygen fraction and risk of major respiratory complications. Br J Anaesth 2017;119:140-9. Crossref
6. Patel A, Nouraei SA. Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways. Anaesthesia 2015;70:323-9. Crossref
7. Frumin MJ, Epstein RM, Cohen G. Apneic oxygenation in man. Anesthesiology 1959;20:789-98. Crossref
8. Humphreys S, Rosen D, Housden T, Taylor J, Schibler A. Nasal high-flow oxygen delivery in children with abnormal airways. Pediatr Anaesth 2017;27:616-20. Crossref
9. Ng LY, Chan AK, Lam TW. The use of high-flow nasal oxygen during airway management in a child with epidermolysis bullosa dystrophica and a difficult airway. Anaesth Rep 2019;7:96-9. Crossref
10. Cheng Q, Zhang J, Wang H, Zhang R, Yue Y, Li L. Effect of acute hypercapnia on outcomes and predictive factors for complications among patients receiving bronchoscopic interventions under general anesthesia. PLoS One 2015;10:e0130771. Crossref
11. Erley CL. Cricoid pressure during induction for tracheal intubation in critically ill children: a report from National Emergency Airway Registry for Children. J Emerg Med 2018;55:737. Crossref
 
Authors' reply
Karen KY Leung, MB, BS, MRCPCH1; SW Ku, MB, BS, MRCP1; Ronald CM Fung, MB, ChB, MRCPCH1; WF Hui, MB, ChB, MRCPCH1; CC Au, MB, BS, MRCPCH1; WL Cheung, MB, BS, MRCPCH1; WH Szeto, BNurs, MNurs1; Jeff CP Wong, MB, BS, MRCPCH1; KF Kwan, MB, BS, MRCP (Irel)2; KL Hon, MB, BS, MD1
1 Paediatric Intensive Care Unit, Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong SAR, China
2 Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong SAR, China
 
Corresponding author: Dr KL Hon (ehon@hotmail.com)
 
We thank the authors for pointing out the importance of increasing arterial oxygen reserve to avoid rapid desaturation with all its dire consequences.1 In this regard, we would like to address aspects related to intubation, oxygenation, ventilation and perfusion.
 
This is even more important in conditions such as status asthmaticus, raised intracranial pressure, and pulmonary hypertension. In these scenarios, rapid sequence intubation might be a misnomer. The patient should be allowed an adequate period of 3 to 5 minutes of pre-oxygenation to prevent desaturation during the intubation process.2 3
 
The oxygen reserve index is a great suggestion if oximeter with this function is available. In an emergency, ensuring oxygen saturation remains well above 90% may be the most we can achieve before attempting intubation with an endotracheal tube or laryngeal mask airway. During an emergency, most of us will probably rely on hearing the beeping and seeing the screen of the oxygen saturation monitor instead of carefully oxygenating until oxygen reserve index is above 0.5.
 
Understanding the oxygen saturation curve, the pressure-volume curve, and the pathophysiology of hypoxaemia and ventilation/perfusion mismatch is another fundamental mental process that care providers must continuously go through even during the critical moment of resuscitation, with atelectatic shunting and dead-space ventilation being problems at the two extremes of the pressure-volume curve. The concept of ventilation/perfusion mismatch leading to hypoxaemia is fundamental, with overdistention leading to dead-space ventilation as in critical asthma syndrome and collapse or atelectasis leading to shunting in collapse of a large segment of the lung (Fig).4
 

Figure. Concept of ventilation-perfusion mismatch resulting in hypoxaemia
 
Issues with hypercapnia and hypocapnia are also important in cardiac and cerebral pathologies, and we agree with the authors’ comments about CO2 clearance. Continuous monitoring of arterial CO2 partial pressure and end-tidal CO2 prior to securing an airway in an emergency remains challenging and may be impossible.
 
Last, in emergency situations, the use of a laryngeal mask airway and the use of video laryngoscopes to improve glottic visualisation are all important routine methods to avoid hypoxaemia and ensure good oxygenation during emergency resuscitation.
 
Author contributions
Concept or design: KL Hon.
Acquisition of data: KL Hon, KKY Leung.
Analysis or interpretation of data: KL Hon, KKY Leung.
Drafting of the reply: KL Hon, KKY Leung.
Critical revision of the reply for important intellectual content: All authors.
 
All authors had full access to the data, contributed to the reply, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
As an editor of the journal, KL Hon was excluded from the review process for this reply. Other authors have disclosed no conflicts of interest.
 
Funding/support
This reply received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Ng D, Cheung C, Wu WY. Better preparation for intubation. Hong Kong Med J 2023;29:178-9. Crossref
2. Mace SE. Challenges and advances in intubation: rapid sequence intubation. Emerg Med Clin North Am 2008;26:1043-68. Crossref
3. Leung KK, Ku SW, Fung RC, et al. Airway management in children with COVID-19. Hong Kong Med J 2022;28:315-20. Crossref
4. Hon KL, Leung AK. Medications and recent patents for status asthmaticus in children. Recent Pat Inflamm Allergy Drug Discov 2017;11:12-21. Crossref

Suggestions to minimise hesitancy and promote vaccination of children in Hong Kong

Hong Kong Med J 2023 Feb;29(1):86 | Epub 6 Jan 2023
https://doi.org/10.12809/hkmj2210487
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Suggestions to minimise hesitancy and promote vaccination of children in Hong Kong
Jeffrey Chan1; KS Ng, PhD2; Benny YC Hon, PhD3,4; Simon C Lam, PhD, RN5
1 King George V School, Hong Kong
2 Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
3 Department of Mathematics, City University of Hong Kong, Hong Kong
4 Department of Psychology, The University of Science and Technology of China, Hefei, China
5 School of Nursing, Tung Wah College, Hong Kong
 
Corresponding author: Prof Simon C Lam (simlc@alumni.cuhk.net)
 
 Full paper in PDF
 
 
To the Editor—Coronavirus disease 2019 (COVID-19) vaccine hesitancy was high initially1 but persists in Hong Kong. As of 2 January 2023, 93.0% and 83.3% of the population had received the second and third doses of the COVID-19 vaccine, respectively.2 However, vaccination uptake for the third dose was only 77.06% for age-group of 12-19 years and 30.92% for those aged 3-11 years.2 The government intends to lower the vaccine pass age limit to 5 years and allow schools to hold full-day face-to-face classes only if 90% of students have received three doses of vaccine before 1 November 2022. According to one study,3 there are four reasons for parental vaccine refusal: religious beliefs, personal beliefs or philosophical reasons, safety concerns, and a desire for more information from healthcare providers. Clearly the reason for the low vaccination rate in Hong Kong is mainly due to safety concerns. The Centre for Health Protection of the Department of Health publishes public health recommendations for the Hong Kong Childhood Immunisation Programme. Advised vaccines from birth onwards include Bacillus Calmette-Guérin, hepatitis B, and diphtheria, tetanus, acellular pertussis and inactivated poliovirus vaccines. Although the side-effects of these vaccines, such as low fever, redness, and a sore arm, are well known, parents do not oppose their administration. We recommend that the Department of Health collaborate with the Education Bureau to implement measures that can improve vaccine uptake. These include: provision of more scientific information, educational and on-site vaccination interventions to schools with a low vaccination rate,4 measures to enhance the biological literacy of school children to encourage vaccination, rapid response by healthcare professionals to dispel rumours and conspiracy theories, education of parents about the benefits of vaccination, and provision of educational seminars via Zoom as continued regular education has been shown to improve the success of vaccination programmes.5 In addition, the Centre for Health Protection may consider other options such as delivering a fractional dose to minimise the side-effects. Another study6 suggests that using an intradermal fractional dose (10-20% the amount of the original dose) vaccination using a microneedle patch can result in better immunogenicity. Side-effects are the most common concern among those who are hesitant or opposed to vaccination. As the safety profile of fractional doses is comparable to that of a regular dose,7 fractional dosages may help combat such hesitancy.
 
Author contributions
All authors contributed to the drafting of the letter and critical revision for important intellectual content. All authors approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
The authors have declared no conflicts of interest.
 
Funding/support
The work of this letter was supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region (Project No.: CityU 11303521).
 
References
1. Yu BY, Lam JC, Lam SC, et al. COVID-19 vaccine hesitancy and resistance in an urban Chinese population of Hong Kong: a cross-sectional study. Hum Vaccin Immunother 2022;18:2072144. Crossref
2. Hong Kong SAR Government. Hong Kong vaccination dashboard. Available from: https://www.covidvaccine.gov.hk/en/dashboard. Accessed 2 Jan 2023.
3. McKee C, Bohannon K. Exploring the reasons behind parental refusal of vaccines. J Pediatr Pharmacol Ther 2016;21:104-9. Crossref
4. Gellert P, Bethke N, Seybold J. School-based educational and on-site vaccination intervention among adolescents: study protocol of a cluster randomised controlled trial. BMJ Open 2019;9:e025113. Crossref
5. Akther T, Nur T. A model of factors influencing COVID-19 vaccine acceptance: a synthesis of the theory of reasoned action, conspiracy theory belief, awareness, perceived usefulness, and perceived ease of use. PLoS One 2022;17:e0261869. Crossref
6. Migliore A, Gigliucci G, Di Marzo R, Russo D, Mammucari M. Intradermal vaccination: a potential tool in the battle against the COVID-19 pandemic? Risk Manag Healthc Policy 2021;14:2079-87. Crossref
7. Yang B, Huang X, Gao H, Leung N, Tsang T, Cowling B. Immunogenicity, efficacy, and safety of SARS-CoV-2 vaccine dose fractionation: a systematic review and meta-analysis. BMC Med 2022;20:409. Crossref
 

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