Uses and abuses of paediatric electroencephalography

ABSTRACT

Hong Kong Med J 2012;18:25–9 | Number 1, February 2012
ORIGINAL ARTICLE
Uses and abuses of paediatric electroencephalography
WC Lee, SS Man, KW Lau, LC Cheng, NS Kwong, Karen L Kwong
Department of Paediatrics, Tuen Mun Hospital, Tuen Mun, Hong Kong
 
 
OBJECTIVE. To investigate whether requests for standard paediatric electroencephalograms accord with guideline recommendations, subsequent changes in clinical management according to reported results, and extent to which the service meets waiting time targets.
 
DESIGN. Case series.
 
SETTING. Regional hospital, Hong Kong.
 
PATIENTS. All patients aged less than 18 years who underwent electroencephalography between December 2009 and February 2010.
 
MAIN OUTCOME MEASURES. Appropriateness of the electroencephalogram request and the impact of its findings on clinical management.
 
RESULTS. A total of 109 patients were recruited, but requests for standard electroencephalograms were considered 'inappropriate' with respect to guidelines in 44% of the patients, of which 50% were made to diagnose 'funny turns'. The standard electroencephalogram contributed to the diagnosis or management in only 28% of patients. In all of the latter, the request for an electroencephalogram had been appropriate. Non-specialists made referrals for 86% of the patients. Inadequate information was provided in 66% of the requests. Standard electroencephalograms were performed within guideline targets, the wait being less than 4 weeks in 95% of requests.
 
CONCLUSION. An effective electroencephalogram service was being provided, though abuses were common. These were mainly because of misconceptions regarding the role and limitations of standard electroencephalograms. Through an educative, non-confrontational approach, and with time to explain guideline recommendations to clinicians, sustainable change in practice could be achieved so as to benefit patients, clinicians, and service provision.
 
Key words: Child; Electroencephalography; Hospitals, district; Practice guidelines as topic; Utilization review
 
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In-house human immunodeficiency virus-1 genotype resistance testing to determine highly active antiretroviral therapy resistance mutations in Hong Kong

ABSTRACT

Hong Kong Med J 2012;18:20–4 | Number 1, February 2012
ORIGINAL ARTICLE
In-house human immunodeficiency virus-1 genotype resistance testing to determine highly active antiretroviral therapy resistance mutations in Hong Kong
Jonathan HK Chen, KH Wong, Patrick CK Li, Kenny KC Chan, MP Lee, Sabrina WC To, WC Yam
Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong
 
 
OBJECTIVE. To determine the frequency of highly active antiretroviral therapy resistance mutations in the viral pol gene of human immunodeficiency virus-1 (HIV-1) genotypes that circulate in Hong Kong, by means of an in-house HIV-1 genotyping system.
 
DESIGN. Retrospective study.
 
SETTING. Two HIV clinics in Hong Kong.
 
PATIENTS. A modified in-house genotyping resistance test was used to sequence the partial pol gene in 1165 plasma samples from 965 patients. The performance of our test was cross-compared with the US Food and Drug Administration-approved ViroSeq HIV-1 genotyping system. The results of genotyping were submitted to the Stanford HIV-1 drug resistance database for analysis.
 
RESULTS. The cost-effective in-house genotypic resistance test (US$40) demonstrated comparable performance to the US Food and Drug Administration-approved ViroSeq system. The detection limit of this in-house genotypic resistance test could reach 400 copies/mL for both HIV-1 subtype B and CRF01_AE, which were the predominant genotypes in Hong Kong. Drug resistance mutations were detected only in post-treatment samples from treatment-failure patients. However, there was no significant difference in the frequency of drug resistance mutations between subtype B and CRF01_AE.
 
CONCLUSION. Our cost-effective in-house genotypic resistance test detected no significant difference in drug resistance-related mutations frequencies between HIV-1 subtype B and CRF01_AE in Hong Kong. A drug resistance-related mutations database for different HIV-1 genotypes should be established in Hong Kong to augment guidance for HIV treatment.
 
Key words: Antiretroviral therapy, highly active; HIV-1; Drug resistance, viral; Genotype; Mutation, missense
 
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Predictors of successful outcomes after external cephalic version in singleton term breech pregnancies: a nine-year historical cohort study

ABSTRACT

Hong Kong Med J 2012;18:11–9 | Number 1, February 2012
ORIGINAL ARTICLE
Predictors of successful outcomes after external cephalic version in singleton term breech pregnancies: a nine-year historical cohort study
LY Cho, WL Lau, TK Lo, Helen HT Tang, WC Leung
Department of Obstetrics and Gynaecology, Kwong Wah Hospital, 25 Waterloo Road, Hong Kong
 
 
OBJECTIVE. To study the success rate, predictors for success, and pregnancy outcomes after external cephalic version.
 
DESIGN. Historical cohort study.
 
SETTING. Regional hospital, Hong Kong.
 
PATIENTS. All women who had singleton term breech pregnancies at term and opted for external cephalic version during 2001 and 2009. Their demographic data, clinical and ultrasound findings, procedure details, complications, and delivery outcomes were analysed.
 
MAIN OUTCOME MEASURES. Predictive factors for successful external cephalic version.
 
RESULTS. A total of 209 external cephalic versions were performed during the 9-year period. The success rate was 63% (75% for multiparous and 53% for nulliparous women). There was no significant complication. On univariate analysis, predictors of successful external cephalic version were: multiparity, unengaged presenting part, higher amniotic fluid index (≥10 cm), thin abdominal wall, low uterine tone, and easily palpable fetal head (subjective assessment by practitioners before external cephalic version). On multivariate analysis, only multiparity, non-engagement of the fetal buttock and thin maternal abdomen were associated with successful external cephalic version. In all, 69% of those who had successful external cephalic version succeeded in the first roll (P<0.001), and 82% of the women with successful external cephalic versions had vaginal deliveries (93% in multiparous and 69% in nulliparous women). Uptake rate of external cephalic version was studied in the latter part of the study period (2006-2009). Whilst 735 women were eligible for external cephalic version, 131 women chose to have the procedure resulting in an uptake rate of 18%.
 
CONCLUSION. External cephalic version was effective in reducing breech presentations at term and corresponding caesarean section rates, but the uptake rate was low. Further work should address the barriers to the low acceptance of external cephalic version. The results of this study could encourage women to opt for external cephalic version.
 
Key words: Breech presentation; Cesarean section; Version, fetal
 
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Cancellation of elective operations on the day of intended surgery in a Hong Kong hospital: point prevalence and reasons

ABSTRACT

Hong Kong Med J 2012;18:5–10 | Number 1, February 2012
ORIGINAL ARTICLE
Cancellation of elective operations on the day of intended surgery in a Hong Kong hospital: point prevalence and reasons
CH Chiu, Anna Lee, PT Chui
Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
 
 
OBJECTIVE. To determine the point prevalence of elective surgical case cancellations and the reasons.
 
DESIGN. Cross-sectional study.
 
SETTING. Teaching hospital, Hong Kong.
 
PATIENTS. Operating theatre records of elective surgery cancellations from 1 January 2009 to 31 December 2009 were retrospectively reviewed.
 
MAIN OUTCOME MEASURES. Cancellation of scheduled elective surgery on the day of surgery and the corresponding reasons.
 
RESULTS. Of 6234 cases scheduled, 476 were cancelled, which yielded a point prevalence of 7.6%, with a 95% confidence interval of 7.0-8.3%. The highest number of cancellations occurred in patients scheduled for major general surgical procedures (n=94, 20%), major urological procedures (n=64, 13%), major orthopaedic surgery (n=38, 8%), and ultra-major cardiothoracic surgery (n=29, 6%). The most common category for cancellation was facility (73%), followed by work-up (17%), patient (10%), and surgeon (1%). No available operating room time due to overrun of the previous surgery was the most common reason for case cancellation (n=310). Compared to general surgery, the odds of no available operating time was significantly less in orthopaedics (odds ratio=0.26; 95% confidence interval, 0.17-0.39), otolaryngology (0.25; 0.13-0.46), neurosurgery (0.36; 0.16-0.70), paediatrics (0.53; 0.31-0.87), gynaecology (0.18; 0.11-0.29), ophthalmology (0.19; 0.07-0.41), and dentistry (0.10; 0.00-0.60).
 
CONCLUSIONS. Case cancellations were mainly due to facility factors, such as no operating room time being available. The odds of having no operating room time available varied between surgical specialties.
 
Key words: Appointments and schedules; Efficiency, organizational; Operating rooms; Quality improvement; Surgical procedures, elective
 
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Secondary prevention of stroke: an evidence-based clinical audit in the primary care

ABSTRACT

Hong Kong Med J 2011;17:469–77 | Number 6, December 2011
ORIGINAL ARTICLE
Secondary prevention of stroke: an evidence-based clinical audit in the primary care
Catherine XR Chen, SL Chan, TC Law, SK Choi, KH Chan
Department of Family Medicine & GOPC, Queen Elizabeth Hospital, 30 Gascoigne Road, Kowloon, Hong Kong
 
 
OBJECTIVE. To audit secondary preventive care in non-acute stroke patients in a local General Outpatient Clinic of the Hospital Authority.
 
DESIGN. Comparison of two samples from a case series at different time-points.
 
SETTING. General Outpatient Clinic, Hong Kong.
 
PATIENTS. Non-acute stroke patients fulfilling the inclusion criteria and regularly followed up in a local General Outpatient Clinic during the audit cycle were recruited. Evidence-based audit criteria and performance standards were established after thorough literature review. A sample from this case series was compared retrospectively at two time-points. First-phase evaluation was performed in October 2009 and deficiencies were identified. After 9 months of active intervention, second-phase evaluation was performed in July 2010. Chi squared test and student's t test were used to compare the significance of relevant changes noted.
 
RESULTS. First-phase data showed marked deficiencies in proper assessment of cardiovascular risk factors. Satisfactory blood pressure, glucose and lipid control was evident only in 47% of the hypertensive, 45% of the diabetic, and 37% of the dyslipidaemic stroke patients, respectively. After 9 months of implementing changes, significant improvements were noted with respect to standard targets being achieved. In the second phase, more comprehensive tackling of cardiovascular risk factors was noted, with satisfactory blood pressure control in 73% of hypertensive patients, and adequate metabolic control in 62% diabetic patients (P<0.01 for both). Only 59% of the dyslipidaemic stroke patients had optimal lipid control, though their mean low-density lipoprotein concentration was significantly reduced (P<0.05).
 
CONCLUSION. This study provided a valuable lesson in identifying deficiencies in secondary prevention for stroke patients managed in a local primary care facility. Using a team approach intervention, quality assurance was promoted and a definite impact on patient care was demonstrated.
 
Key words: Cardiovascular diseases; Guideline adherence; Hypertension; Secondary prevention; Stroke
 
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Single-incision laparoscopic cholecystectomy: from four wounds to one

ABSTRACT

Hong Kong Med J 2011;17:465–8 | Number 6, December 2011
ORIGINAL ARTICLE
Single-incision laparoscopic cholecystectomy: from four wounds to one
Jeff SW Wong, YS Cheung, KW Chan, Charing CN Chong, KF Lee, John Wong, Paul BS Lai
Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
 
 
OBJECTIVE. To review the initial results and surgical outcomes of single-incision laparoscopic cholecystectomy.
 
DESIGN. Prospective case series.
 
SETTING. A university teaching hospital and a regional hospital in Hong Kong.
 
PATIENTS. All patients undergoing single-incision laparoscopic cholecystectomy from August 2009 to March 2011.
 
RESULTS. Fifty patients underwent single-incision laparoscopic cholecystectomy during the study period. The indications for surgery included symptomatic gallstones (n=43) and gallbladder polyps (n=7). The mean operating time was 78 (standard deviation, 24) minutes. Forty-five of the patients successfully underwent single-incision laparoscopic cholecystectomy, giving a success rate of 90%. In the remaining five patients, additional working ports were constructed to obtain better exposure and dissection around Calot's triangle. On comparing the results of the initial 25 cases to the subsequent 25 cases, in the latter group the operating time was significantly shorter (86 vs 71 minutes; P=0.02), and the success rate was higher (80% vs 100%; P=0.05). During the median follow-up period of 6.8 months, four patients had complications, which included: postoperative urinary retention (n=2), one each with a haematoma and an incisional hernia. No patient endured bile duct injury, postoperative bile leakage, or haemorrhage in our series.
 
CONCLUSION. Single-incision laparoscopic cholecystectomy is feasible and safe for treatment of uncomplicated gallbladder diseases. There was a reduction in the operating time and increase in success rate with accumulation of experience. Nevertheless, surgeons should be cautious about the potential risks of this new technique.
 
Key words: Cholecystectomy, laparoscopic; Cholelithiasis; Treatment outcome
 
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Development of the Chinese version of the Paediatric Allergic Disease Quality of Life Questionnaire: reliability and validity

ABSTRACT

Hong Kong Med J 2011;17:460–4 | Number 6, December 2011
ORIGINAL ARTICLE
Development of the Chinese version of the Paediatric Allergic Disease Quality of Life Questionnaire: reliability and validity
Daniel K Ng, Kenneth CW Wong, CH Chan, Eugene P Ng
Department of Paediatrics, Kwong Wah Hospital, Kowloon, Hong Kong
 
 
OBJECTIVE. Paediatric Allergic Disease Quality of Life Questionnaire is a health-related assessment tool designed for children with allergic diseases. This study aimed to translate the original English version of the Questionnaire to Chinese and to provide psychometric evidence on the validity and reliability of the translated version.
 
DESIGN. Cross-sectional study.
 
SETTING. Out-patient clinic of a non-teaching hospital in Hong Kong.
 
PARTICIPANTS. The Paediatric Allergic Disease Quality of Life Questionnaire was translated to Chinese and then completed by a group of 115 Hong Kong Chinese children (66 male and 49 female; mean age, 11 years) with allergic disease(s). All subjects were asked to respond using visual analogue scales dealing with issues related to the perceived morbidity of allergic diseases. To assess test-retest reliability, 2 weeks later a subgroup of 16 individuals was retested with the same Questionnaire.
 
RESULTS. The internal consistency of the Chinese Paediatric Allergic Disease Quality of Life Questionnaire was satisfactory (Cronbach alpha=0.92). The correlation between the total Questionnaire score and the visual analogue scale score was moderately significant (Spearman's rho=0.49; 95% confidence interval, 0.34-0.62). Structural validity as studied by confirmatory factor analysis found that the structure of subscales was remarkably similar to the original English version. The intra-class correlation between the Questionnaire score from the first and the second test in the subgroup of 16 subjects was 0.75, indicating adequate repeatability.
 
CONCLUSION. The validity and reliability of the Chinese version of the Paediatric Allergic Disease Quality of Life Questionnaire was established for clinical use.
 
Key words: Asthma; Child; Eczema; Quality of life; Rhinitis, allergic, perennial
 
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Intracranial electroencephalogram to evaluate refractory temporal and frontal lobe epilepsy

ABSTRACT

Hong Kong Med J 2011;17:453–9 | Number 6, December 2011
ORIGINAL ARTICLE
Intracranial electroencephalogram to evaluate refractory temporal and frontal lobe epilepsy
Lisa Au, Howan Leung, Patrick Kwan, XL Zhu, Danny TM Chan, HT Wong, WS Poon, Venus YH Tang, Sam KS Ng, Deyond Siu, Tom CY Cheung, PT Choi, KS Wong
Division of Neurology, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
 
 
OBJECTIVE. We undertook a collaborative study in a multidisciplinary team to channel refractory epilepsy patients to test a hypothesis about placement of intracranial electroencephalography arrays.
 
DESIGN. This was a descriptive case series. Prospective non-invasive presurgical evaluations were based on clinical semiology, magnetic resonance imaging, video-electroencephalography findings and neuropsychological assessments. If the results were discordant, a hypothesis was generated using individualised combinations of positron emission tomography, single-photon emission computed tomography, functional magnetic resonance imaging and Wada tests. The indications for intracranial electroencephalography were: (a) focal magnetic resonance imaging, ictal/interictal scalp electroencephalography with variable results (group A); (b) multi-focal magnetic resonance imaging, focal/multi-focal ictal scalp electroencephalography (group B); (c) non-lesional magnetic resonance imaging, focal/multi-focal ictal scalp electroencephalography (group C). We evaluated whether the seizure-onset zones and eloquent areas were delineated, surgical outcomes (if operated on), and pathology results.
 
SETTING. A tertiary referral centre for neurology in Hong Kong.
 
PATIENTS. A total of 105 refractory epilepsy patients completed non-invasive presurgical evaluations over the period 2007 to 2009. Thirty-two patients were eligible for direct resective surgery, and another 25 patients had a testing hypothesis formulated. Of these 25 patients, 10 were eligible for intracranial electroencephalography based on technical/financial considerations.
 
RESULTS. All 10 patients (group A=2, group B=4, group C=4) had their epileptogenic zones defined. Six patients underwent functional mapping, all of whom had their eloquent areas defined. Seven of the 10 patients underwent resective surgery; four of them achieved Engel class I/II outcomes. The dichotomised outcomes were 100% (group A), 50% (group B), and 33% (group C) achieving Engel class I/II. Two patients had asymptomatic subdural haematoma. There was no intracranial infection or operative mortality. In five (71%) of seven of the patients, a histological diagnosis was established.
 
CONCLUSION. Proper deployment of intracranial electroencephalography is useful in the presurgical evaluation of patients with refractory epilepsy. This modality of management is potentially of benefit for patients with refractory epilepsy, but is underutilised locally.
 
Key words: Electrodes; Electroencephalography; Epilepsy; Magnetic resonance imaging
 
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Utilisation and outcome of renal replacement therapy in an Asian tertiary intensive care unit

ABSTRACT

Hong Kong Med J 2011;17:446–52 | Number 6, December 2011
ORIGINAL ARTICLE
Utilisation and outcome of renal replacement therapy in an Asian tertiary intensive care unit
Gordon YS Choi, Gavin M Joynt, Charles D Gomersall, HY So
Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
 
 
OBJECTIVES. To determine the period prevalence, demographic characteristics, cost of treatment, and outcomes of patients admitted to the intensive care unit for continuous renal replacement therapy.
 
DESIGN. Descriptive case series.
 
SETTING. Intensive Care Unit in a Hong Kong tertiary referral, teaching hospital.
 
PATIENTS. All patients admitted to the Intensive Care Unit from January to December 2007 who underwent continuous renal replacement therapy.
 
MAIN OUTCOME MEASURES. Period prevalence of continuous renal replacement therapy, patient demographic data, referral sources by specialty and hospital location, diagnosis, daily cost of disposable items, duration of renal replacement therapy, intensive care unit length of stay, and hospital mortality.
 
RESULTS. Of 1652 patients admitted to the intensive care unit over a 12-month period, 131 (8%) underwent continuous renal replacement therapy, of whom 56% were admitted from general wards (the department of medicine being the source of 59% of referrals). The median age of these continuous renal replacement therapy patients was 67 (interquartile range, 55-76) years, with a slight male predominance (66%). The mean APACHE II score of the patients was 29 (standard deviation, 7). Chronic renal failure requiring either haemodialysis or peritoneal dialysis was present in 20/131 (15%) patients. Sepsis was the diagnosis most commonly associated with renal failure deemed to warrant continuous renal replacement therapy (43%). The median duration of such continuous therapy was 55 (interquartile range, 25-93) hours and the median intensive care unit length of stay was 120 (interquartile range, 51-289) hours. The mean daily cost of disposables for the provision of continuous renal replacement therapy was HK$3510. The overall intensive care unit mortality of patients having continuous renal replacement therapy was 38% and the hospital mortality was 53%. The corresponding rates for patients with acute renal failure were 45% and 56%, respectively. Patients undergoing continuous renal replacement therapy had prolonged intensive care unit stays (120 vs 24 hours; P<0.05) and higher corresponding hospital mortality rates (53% vs 20%; P<0.001) compared to those not having such therapy.
 
CONCLUSION. The 8% period prevalence of patients admitted to the intensive care unit undergoing continuous renal replacement therapy was somewhat higher than in recently published reports in the international literature. However intensive care unit and hospital mortality rates for such patients were lower than previously reported. The corresponding total daily cost of relevant disposables was similar to costs reported internationally, whilst the length of intensive care unit stays for our cohort were relatively short.
 
Key words: Acute kidney injury; Intensive care units; Mortality; Renal replacement therapy
 
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Utility of a preoperative assessment clinic in a tertiary care hospital

ABSTRACT

Hong Kong Med J 2011;17:441–5 | Number 6, December 2011
ORIGINAL ARTICLE
Utility of a preoperative assessment clinic in a tertiary care hospital
Frank WK Chan, Fiona YY Wong, YS Cheung, PT Chui, Paul BS Lai
School of Public Health and Primary Care, The Chinese University of Hong Kong, Shatin, Hong Kong
 
 
OBJECTIVES. To assess the utilisation rate of a preoperative assessment clinic and its impact on length of stay and discharge destinations.
 
DESIGN. Retrospective case series with internal comparisons.
 
SETTING. A tertiary hospital in Hong Kong.
 
PATIENTS. All medical records of elective surgical admissions to a hospital in Hong Kong from April to June 2008 were retrieved. Medical records of patients who did not attend the preoperative assessment clinic were further reviewed by surgeons to assess if the patients could have been referred to the clinic.
 
MAIN OUTCOME MEASURES. Total length of stay, preoperative and postoperative length of stay, and the discharge destinations of the patients attending and not attending the clinic were compared.
 
RESULTS. In all, 640 patients underwent elective operations, of whom 22 (3%) patients were seen in the preoperative assessment clinic. In patients who had a major operation, the mean (standard deviation) total length of stays for clinic attenders and non-attenders were: 5.2 (3.6) versus 13.2 (18.8) days (P<0.001). The respective figures for preoperative and postoperative length of stay were: 1.3 (2.3) versus 4.5 (8.9) days (P=0.001), and 3.9 (2.9) versus 8.7 (14.5) days (P<0.001). For patients who had an intermediate operation, the respective mean (standard deviation) length of hospital stays were 2.4 (2.0) versus 7.3 (13.9) days (P=0.002) and the figures for postoperative length of stays were 1.3 (0.5) versus 4.5 (9.3) days (P=0.001). Surgeons had classified 108 (17%) of the cases as possible preoperative assessment clinic users. Among the latter, 71 (66%) had no special reason to stay in the hospital. The discharge destination was not associated with the use of preoperative assessment clinic for patients having major (Chi squared=0.18, P=0.912) or intermediate (Chi squared=0.34, P=0.468 operations.
 
CONCLUSION. Successful implementation of preoperative assessment clinic service requires close collaboration between surgeons, anaesthetists, clinicians, and also the re-engineering of health service delivery.
 
Key words: Length of stay; Outcome and process assessment (health care); Patient discharge; Preoperative care; Surgical procedures, operative
 
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