Displaying publications 21 - 40 of 2986 in total

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  1. Lau S, Ng KH, Abdul Aziz YF
    Br J Radiol, 2016 Oct;89(1066):20160258.
    PMID: 27452264 DOI: 10.1259/bjr.20160258
    OBJECTIVE: To investigate the sensitivity and robustness of a volumetric breast density (VBD) measurement system to errors in the imaging physics parameters including compressed breast thickness (CBT), tube voltage (kVp), filter thickness, tube current-exposure time product (mAs), detector gain, detector offset and image noise.

    METHODS: 3317 raw digital mammograms were processed with Volpara(®) (Matakina Technology Ltd, Wellington, New Zealand) to obtain fibroglandular tissue volume (FGV), breast volume (BV) and VBD. Errors in parameters including CBT, kVp, filter thickness and mAs were simulated by varying them in the Digital Imaging and Communications in Medicine (DICOM) tags of the images up to ±10% of the original values. Errors in detector gain and offset were simulated by varying them in the Volpara configuration file up to ±10% from their default values. For image noise, Gaussian noise was generated and introduced into the original images.

    RESULTS: Errors in filter thickness, mAs, detector gain and offset had limited effects on FGV, BV and VBD. Significant effects in VBD were observed when CBT, kVp, detector offset and image noise were varied (p 

    Matched MeSH terms: Retrospective Studies
  2. Keserci B, Duc NM, Nadarajan C, Huy HQ, Saizan A, Wan Ahmed WA, et al.
    Diagn Interv Radiol, 2020 May;26(3):207-215.
    PMID: 32209511 DOI: 10.5152/dir.2019.19157
    PURPOSE: We sought to present our preliminary experience on the effectiveness and safety of magnetic resonance imaging (MRI)-guided, high-intensity focused ultrasound (HIFU) therapy using a volumetric ablation technique in the treatment of Association of Asian Nations (ASEAN) patients with symptomatic uterine leiomyomas.

    METHODS: This study included 33 women who underwent HIFU treatment. Tissue characteristics of leiomyomas were assessed based on T2- and T1-weighted MRI. The immediate nonperfused volume (NPV) ratio and the treatment effectiveness of MRI-guided HIFU on the basis of the degrees of volume reduction and improvement in transformed symptom severity score (SSS) were assessed.

    RESULTS: The median immediate NPV ratio was 89.8%. Additionally, the median acoustic sonication power and HIFU treatment durations were 150 W and 125 min, respectively. At six-month follow-up, the median leiomyoma volume had decreased from 139 mL at baseline to 84 mL and the median transformed SSS had decreased from 56.2 at baseline to 18.8. No major adverse events were observed.

    CONCLUSION: The preliminary results demonstrated that volumetric MRI-guided HIFU therapy for the treatment of symptomatic leiomyomas in ASEAN patients appears to be clinically acceptable with regard to treatment effectiveness and safety.

    Matched MeSH terms: Retrospective Studies
  3. Lo TS, Harun F, Alzabedi A, Chiung HK, Jhang LS, Hsieh WC
    J Minim Invasive Gynecol, 2024 Feb;31(2):102-109.
    PMID: 37952873 DOI: 10.1016/j.jmig.2023.11.003
    STUDY OBJECTIVE: To determine the outcome of voiding function 1 year after pelvic reconstructive surgery (PRS) in women with bladder outlet obstruction (BOO).

    DESIGN: Retrospective cohort study.

    SETTING: Tertiary referral hospital.

    PATIENTS: A total of 1894 women underwent PRS for advanced pelvic organ prolapse (POP) stages 3 to 4 with urodynamic findings of BOO.

    INTERVENTIONS: PRS.

    MEASUREMENTS: The primary outcome measured was the resumption of normal voiding function, defined clinically with multichannel urodynamic testing at 1 year postoperatively. The secondary outcomes were to identify the different risk factors for persistence voiding dysfunction (VD) 1 year after PRS.

    MAIN RESULTS: A total of 431 women with Pelvic Organ Prolapse Quantification stages 3 and 4, urodynamic study of maximum urinary flow rate ≤15 mL/s, and detrusor pressure at maximum flow ≥20 cm H2O were included. Resumption of normal voiding function was found in 91% (n = 392 of 431), whereas 9% (n = 39 of 431) remained to have VD 1 year postoperatively. Those with persistent VD, 20.5% (n = 8 of 39) remained having urodynamic diagnosis of BOO. Univariate and multivariate logistic regression revealed factors associated with postoperative VD were pre-operative maximal cystometric capacity ≥500 mL and postvoid residual volume ≥200 mL.

    CONCLUSION: VD may persist in women with BOO after PRS, particularly in those with preoperative maximal cystometric capacity of >500 mL and postvoid residual volume >200 mL.

    Matched MeSH terms: Retrospective Studies
  4. Hasan AN, Mustapha M, Wan HAHW
    Cesk Slov Oftalmol, 2024;80(Ahead of print):1-5.
    PMID: 38413229 DOI: 10.31348/2024/1
    AIMS: We present the clinical spectrum, the initial clinical presentation with management trends in treating 14 Vogt-Koyanagi-Harada (VKH) disease cases in a tertiary center in the Northern part of Malaysia.

    CASE SERIES: There were 14 cases of Vogt-Koyanagi-Harada (VKH) disease retrospectively reviewed over five years (from 2015 to 2020). The mean age at presentation was 37.7 years (range 21-64 years), with female predominance (85.7%). All cases presented with acute uveitic stage and bilateral eye involvement. Of them, 11 (78.6%) were probable VKH, and three (21.4%) were incomplete VKH. All patients attended with acute panuveitis at first presentation. The main posterior segment involvement was disc edema in 57.1% (16 out of 28 eyes) and exudative retinal detachment (ERD) in 35.7% (10 out of 28 eyes). Most of them presented with blindness (3/60 and worse) and moderate visual impair- ment (6/18-6/60); 35.71% each, followed by mild visual impairment (6/12-6/18), and severe visual impairment (6/60-3/60); 7.1% each. Ten patients (71.4%) required combination second-line immunomodulatory treatment during subsequent visits, and only four patients (28.6%) responded well to corticosteroid therapy. Most of the cases achieved no visual impairment (64.3%), followed by mild visual impairment (21.4%) and moderate visual impairment (14.3%), and none were severe or blind at the end of follow-up.

    CONCLUSION: VKH is a potentially blinding illness if there is inadequate control of the disease in the acute stage. Most of our patients achieved good visual outcomes with early immunomodulatory treatment and systemic corticosteroids.

    Matched MeSH terms: Retrospective Studies
  5. Thevi T, Abas AL
    Oman J Ophthalmol, 2018 6 23;11(2):113-118.
    PMID: 29930443 DOI: 10.4103/ojo.OJO_220_2016
    BACKGROUND: Cataract surgery is associated with a variety of complications, one of which is vitreous loss. Doctors and policymakers should be aware about the precipitating factors, associations, and expected outcomes of vitreous loss. This study was, therefore, undertaken to set guidelines to improve the visual outcomes of patients.

    MATERIALS AND METHODS: A retrospective 8-year analysis was conducted from 2007 to 2014 using the national eye database. Demographic features, ocular comorbidities, grade of surgeon, type of surgery, and the associations with the occurrence of vitreous loss, and the final visual outcomes of these patients were studied.

    RESULTS: Out of 12,992 eyes, only 3.2% had vitreous loss, mostly aged <40 years. Pseudoexfoliation was the only ocular comorbidity causing vitreous loss. Medical Officers and Gazetting Specialists got more vitreous loss compared to specialists. Intracapsular cataract extraction, phaco convert to extracapsular cataract extraction (ECCE), ECCE, and phaco all had a significant vitreous loss. Vitreous loss was the most significant intraoperative complication causing poor vision and resulted in impaired or poor visual outcome.

    CONCLUSION: Vitreous loss occurred in almost all types of cataract surgeries, especially by junior surgeons, among those aged <40 years and significantly caused poor visual outcome compared to other complications. Pseudoexfoliation had higher occurrence of vitreous loss. Vitreous loss patients had impaired/poor visual outcome due to preexisting comorbidity and astigmatism. Patients at risk and junior surgeons should be closely monitored to improve outcomes. Further studies need to be done to see why and when the vitreous loss occurred.
    Matched MeSH terms: Retrospective Studies
  6. Bastion, M.L.C., Amelah, M.A.Q., Wong, H.S.
    MyJurnal
    This study aimed to review the risk factors and clinical outcomes of patients undergoing pars planar vitrectomy (PPV) for breakthrough bleeding (BTB) from age related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). We performed a retrospective review of medical records of 346 patients operated by the vitreoretinal unit at Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Kuala Lumpur, Malaysia from January 2008 - June 2011. We found eight eyes of 8 patients with AMD/IPCV-related BTB who underwent PPV. Mean age of patients was 64.4 years (range 41-80 years) with 5 males. Five were Chinese. Duration of symptoms ranged from days to months. Four patients were on anti-coagulants. Two had history of prior photodynamic therapy. There were five cases of PCV, of which three were macular in location. All three cases of AMD were macular. Intraoperative intravitreal ranibizumab injection was given in three cases and two had combined vitrectomy and cataract extraction. All cases reported improvement in visual acuity with four cases achieving 6/60 or better post operatively including two cases of extramacular PCV achieving 6/9 vision. Mean follow-up was 60 weeks. Postoperative complications included retinal tear and detachment in one case, reattached on reoperation. Six patients had a history of hypertension including one individual with stroke. Our small series indicates a predominance of Chinese individuals with BTB. Usage of anticoagulants and hypertension may be a predisposing factor. Better visual prognosis occurs with extramacular lesions which tend to be of PCV type.
    Matched MeSH terms: Retrospective Studies
  7. Ong SG, Ding HJ
    Med J Malaysia, 2019 12;74(6):492-498.
    PMID: 31929474
    INTRODUCTION: Numerous studies have found that a majority of systemic lupus erythematosus (SLE) patients have suboptimal vitamin D levels. The major contributory factor is most likely attributed to sun protection measures in order to avoid SLE flares. The objectives of this research included the assessment of vitamin D status and its association with clinical manifestations of SLE, cardiovascular risk factors, autoantibodies, SLE disease activity and damage accrual.

    METHOD: This retrospective study involved SLE patients who attended the Rheumatology Clinic at the Hospital Kuala Lumpur from January 2014 to December 2016. Vitamin D was categorised as normal, insufficient or deficient, and the clinical variables were compared across vitamin D categories with chi-squared tests and Pearson correlation coefficient.

    RESULTS: We included 216 patients. The mean 25(OH)D concentration was 51.3(Standard Deviation; SD 14.8) nmol/L. Fifty (23.1%) patients had vitamin D deficiency, 120 (55.6%) had vitamin D insufficiency, while 46 (21.3%) had adequate vitamin D levels. There were statistically significant associations between vitamin D status and ethnic group, lupus nephritis and hypertension. No correlations were observed between vitamin D status with SLEDAI score (Pearson correlation coefficient -0.015, p=0.829) as well as SDI score (Pearson correlation coefficient -0.017, p=0.801).

    CONCLUSION: SLE patients should be screened for vitamin D concentrations and their levels optimised.

    Matched MeSH terms: Retrospective Studies
  8. Ngai M, Lin V, Wong HC, Vathsala A, How P
    Clin. Nephrol., 2014 Oct;82(4):231-9.
    PMID: 25161115 DOI: 10.5414/CN108182
    BACKGROUND: Vitamin D deficiency is associated with secondary hyperparathyroidism and mineral and bone disorder (MBD) in chronic kidney disease (CKD). This study aimed to determine the prevalence of vitamin D insufficiency/deficiency, and the association between vitamin D status and MBD in a multi-ethnic CKD population in Southeast Asia.

    METHODS: Predialysis CKD patients were included in this cross-sectional study. Patient demographics, medical/medication histories, and laboratory parameters (serum 25-hydroxyvitamin D (25(OH)D), creatinine, phosphate (P), calcium, albumin, and intact-PTH (i-PTH)) were collected and compared among patients with various CKD stages. The association between 25(OH)D and these parameters was determined by multiple linear regression.

    RESULTS: A total of 196 patients with mean ± SD eGFR of 26.4 ± 11.2 mL/min/1.73 m2 was included. Vitamin D deficiency (25(OH)D concentration < 15 ng/mL) and insufficiency (25(OH)D concentration 16 - 30 ng/mL) was found in 29.1% and 57.7% of the patients, respectively. Mean ± SD serum 25(OH)D was 20.8 ± 9.3 ng/mL. Female patients had lower vitamin D concentrations than males (16.9 ng/mL vs. 23.9 ng/mL; p < 0.001). Vitamin D levels were also higher in Chinese (22.3 ng/mL) than Malay (17.3 ng/mL) and Indian (13.1 ng/mL) patients (p < 0.05). Nonadjusted analyses showed higher i-PTH concentration in vitamin D deficient patients (p < 0.05).

    CONCLUSION: Despite being a sun-rich country all year round, the majority (86.8%) of predialysis CKD patients in Singapore have suboptimal vitamin D status. Lower vitamin D concentrations were found in females and in those with darker skin tone. Vitamin D deficient patients also tended to have higher i-PTH levels.

    Matched MeSH terms: Retrospective Studies
  9. Yikilmaz AŞ, Akinci S, Bakanay ŞM, Dilek İ
    Malays J Med Sci, 2020 Feb;27(1):70-77.
    PMID: 32158346 DOI: 10.21315/mjms2020.27.1.7
    Introduction: Vitamin D, which is known for its effects on calcium and bone metabolism, has recently been associated with haematological malignancies. We aimed to investigate the relationship between disease findings and vitamin D deficiency in essential thrombocythemia (ET) and polycythemia vera (PV).

    Material and Methods: This retrospective cohort study conducted in Turkey included 73 patients diagnosed with PV or ET according to WHO criteria between 2012 and 2018. Vitamin D deficiency was defined as 25-OH vitamin D < 20 ng/mL. Polymerase chain reaction (PCR) was used to detect the Janus kinase 2 (JAK2) V617F mutation.

    Results: Vitamin D deficiency was found in 66.7% of PV and 74.2% of ET patients. The median follow-up time of ET and PV patients was 48 months and 47 months, respectively. Patients with the JAK2 mutation had a higher prevalence of a history of thrombosis and age older than 65 years. There was a significant relationship between JAK2 positivity and vitamin D deficiency.

    Conclusion: There was a remarkably higher prevalence of vitamin D deficiency in JAK2 mutation-positive ET and PV patients. These patients should be carefully evaluated for vitamin D deficiency. More studies are required to further investigate the association between JAK2 and vitamin D.

    Matched MeSH terms: Retrospective Studies
  10. Linggam, Rachel Clarice, Arifah Nur Bt Yahya, Muhassanah Aliah Bt Baharum
    MyJurnal
    Introduction: Vision is an important requirement for learning and plays a critical role in the development of a child during the first three years of life. Little is known regarding the extent of visual impairment amongst preschool children in Sabah.
    Objective: To determine visual status among preschool children in Kota Kinabalu and to determine prevalence of refractive error among children who were referred by the programme.
    Methodology: A retrospective cohort study of clinical records was conducted at Department of Ophthalmology, Hospital Queen Elizabeth, Kota Kinabalu, Sabah from May to September 2017. Criteria for failed vision were VA 6/12 (0.3 LogMar) or worse. All records of referred children were selected for prevalence of refractive error. Data collected include basic demographic data, visual acuity and refractive error. Myopia was defined as spherical equivalent (SE) ≥−1.00 DS, hyperopia SE ≥+3.00 DS and astigmatism ≥−1.50 DC.
    Results: A total of 192 children age 4 to 6 years old were screened, comprised of 102 (53.1%) male and 90 (46.9%) female (mean age: 5.81 ± 0.41 years). Of the 192 students, 39 (20.3%) of them failed vision screening. Among the 39 children, only 17 children came for further eye assessment. Twelve (70.6%) of them had a binocular visual impairment (VI) while 5 (29.4%) children had monocular VI. Six years old children were found to have VI more compared to other age groups (n= 14, 82.4%) and majority of this age group having binocular VI (n=10, 83.3%). Mean SE was −0.60 ± 0.94. Astigmatism is the commonest type of refractive error found with a prevalence of 41.4% followed by myopia, 27.6%.
    Conclusion: This study was the first attempt to investigate the visual status among preschool in Kota Kinabalu. As most children were found with astigmatism, early detection of significant refractive error could help to minimize the effect of VI.
    Matched MeSH terms: Retrospective Studies
  11. Thevi T, Sahoo S
    Med J Malaysia, 2016 Apr;71(2):45-6.
    PMID: 27326939
    PURPOSE: To analyse the visual outcomes of cases with posterior capsule rupture (PCR) compared to those without PCR following phacoemulsification. The occurrence of posterior capsule rupture during phacoemulsification surgery for cataract can have serious implications in the visual recovery. However, recognition of PCR and proper management can yield a successful visual outcome. This study analysed the visual outcomes of cases with PCR compared to those without PCR.

    METHODS: This is a case-control study. All patients who underwent cataract surgery from 2011 to 2012 in Hospital Melaka were traced from the National Eye Database (NED) of Malaysia. The visual outcomes were classified as good, borderline and poor as per WHO guidelines. The data was analysed with SPSS version 12 IBM.

    RESULTS: Out of 80.4% (2519) of eyes that had undergone phacoemulsification (PHACO) type of surgery, 3.06% (77 cases) had posterior capsule rupture complication. There was no significant difference in the visual outcome of borderline between cases with PCR and cases without PCR (Odds Ratio (OR) 0.989; 95% Confidence Interval (CI) 0.382- 2.560). However, cases with PCR were significantly less likely to have good vision compared to those without PCR (OR 0.335; 95% CI 0.157-0.714).

    CONCLUSION: The study reveals that a significant number of patients without PCR had good vision, whereas those with PCR did not get good vision. We would like to suggest meticulous care during phacoemulsification surgery to avoid PCR in order to obtain good visual outcomes.
    Matched MeSH terms: Retrospective Studies
  12. Waheeda-Azwa H, Norihan I, Tai ELM, Kueh YC, Shatriah I
    Taiwan J Ophthalmol, 2020 02 12;10(4):278-283.
    PMID: 33437601 DOI: 10.4103/tjo.tjo_71_19
    PURPOSE: The available data on strabismus surgery in South East Asian countries are scarce. This study aimed to identify visual outcome and factors influencing surgical outcome of horizontal strabismus surgery in a Southeast Asian cohort.

    MATERIALS AND METHODS: A retrospective review of patients who underwent horizontal strabismus surgery between 2013 and 2017 in Hospital Universiti Sains Malaysia was conducted. Surgery was considered successful if the post-operative deviation was within 10 prism diopters at 6 months' postoperative period. Factors influencing the outcome of surgery at 6 months were identified. Chi-square and Fisher's exact tests were used in data analysis.

    RESULTS: Ninety-eight patients were included. Both genders were equally affected. Exotropia (58.2%) was the most common type. About 65.3% of patients had alternating strabismus, while 51% had an angle of deviation of more than 45 prism diopters. Amblyopia was documented in 14.3% of patients. Those operated on below 10 years of age comprised 64.3%. Ninety-four patients completed follow-ups at 6 months after the surgery. The success rate was 81.6%. Approximately 92% of the patients had best-corrected visual acuities of 6/12 and better at 6 months' postoperative period. There was no significant association between age of onset, gender, presence of amblyopia, type of deviation, amount of deviation, and postoperative best-corrected visual acuity with surgical outcome at 6 months' postoperative period (P > 0.05).

    CONCLUSION: The success rate was good. Postoperative best-corrected visual acuity was promising. Age of onset, gender, presence of amblyopia, type of deviation, amount of deviation, and postoperative best-corrected visual acuity did not influence the outcome of horizontal strabismus surgery in our review.

    Matched MeSH terms: Retrospective Studies
  13. Mohd-Ilham IM, Ahmad-Kamal GR, Wan Hitam WH, Shatriah I
    Cureus, 2019 Apr 08;11(4):e4407.
    PMID: 31205829 DOI: 10.7759/cureus.4407
    Purpose To describe the visual presentation and factors affecting visual outcome in pediatric patients treated for craniopharyngioma at a referral center in the East Coast states of Peninsular Malaysia. Methodology A retrospective review of medical records of children aged 17 years and below who had been treated for craniopharyngioma in Hospital Universiti Sains Malaysia from January 2014 to December 2018. The data collected included age, gender, presenting symptoms and duration, visual acuity, visual fields, color vision, light brightness, relative afferent pupillary defects, fundus examination and cranial nerves examination. The best corrected visual acuity during presentation, and after a one-year post-operative period, was documented. Records on investigations, surgical procedures, therapeutic modalities and recurrences were also reviewed. Results A total of 11 pediatric patients (22 eyes) were recruited. Fifty percent presented with optic atrophy. The mean duration of the onset of symptoms before consultation was 22.3 (24.5) months. A final best corrected visual acuity of 6/12 (20/40) or better was observed in 50% of the patients. There was a statistically significant association between presenting visual acuity, optic nerve function and visual field defects, and the final visual outcome. Conclusions Visual presentations in our study were fairly similar to previous reported studies. One-third presented late with permanent visual loss. Almost half had significant visual impairment after one-year post-operative period. Significant associations were observed between presenting visual acuity, duration of symptoms, impairment of optic nerve function tests, and visual field defects during presentation, and final visual acuity at one year after treatment.
    Matched MeSH terms: Retrospective Studies
  14. Ghoshal R, Sharanjeet-Kaur S, Fadzil NM, Ghosh S, Ngah NF, Aziz RABA
    PMID: 33806713 DOI: 10.3390/ijerph18052581
    The objective of this study was to compare visual parameters and retinal layers' morphology pre-treatment (baseline) and 6 months post-treatment in polypoidal choroidal vasculopathy (PCV) eyes. A single centre, longitudinal, prospective study was conducted at a public tertiary hospital of Malaysia. Visual parameters including distance and near visual acuity (DVA and NVA), contrast sensitivity (CS), reading speed (RS), and different qualitative and quantitative optical coherence tomography (OCT) parameters were evaluated pre- and 6 months post-treatment. Thirty-three naïve PCV eyes of 32 patients (mean age of 67.62 years) were evaluated pre- and post-treatment of intravitreal ranibizumab with and without photodynamic therapy. After treatment, sub retinal fluid decreased from 27 eyes (84.35%) at baseline to 7 eyes (21.88%) at 6 months while pigment epithelium detachment decreased from 32 eyes (100%) at base line to 15 eyes (46.87%) at 6 months. Mean pre-treatment quantitative morphological OCT retinal parameters including thickness and volume of central sub field, center thickness, center minimum, and maximum thickness reduced significantly. Similarly, all visual parameters including DVA, NVA, CS, and RS showed statistically significant improvement. While 89% of the eyes showed improvement in CS, 78%, 71%, and 65% of the eyes showed improvement in NVA, RS, and DVA, respectively. Thus, CS was the most treatment responsive visual parameter.
    Matched MeSH terms: Retrospective Studies
  15. Chia YC, Ching SM, Lim HM
    J Hypertens, 2017 05;35 Suppl 1:S50-S56.
    PMID: 28350621 DOI: 10.1097/HJH.0000000000001333
    OBJECTIVES: The current study aims to determine the relationship of long-term visit-to-visit variability of SBP to cardiovascular disease (CVD) in a multiethnic primary care setting.
    METHOD: This is a retrospective study of a cohort of 807 hypertensive patients over a period of 10 years. Three-monthly clinic blood pressure readings were used to derive blood pressure variability (BPV), and CVD events were captured from patient records.
    RESULTS: Mean age at baseline was 57.2 ± 9.8 years with 63.3% being women. The BPV and mean SBP over 10 years were 14.7 ± 3.5 and 142 ± 8 mmHg, respectively. Prevalence of cardiovascular event was 13%. In multivariate logistic regression analysis, BPV was the predictor of CVD events, whereas the mean SBP was not independently associated with cardiovascular events in this population. Those with lower SBP and lower BPV had fewer cardiovascular events than those with the same low mean SBP but higher BPV (10.5 versus 12.8%). Similarly those with higher mean SBP but lower BPV also had fewer cardiovascular events than those with the same high mean and higher BPV (11.6 versus 16.7%). Other variables like being men, diabetes and Indian compared with Chinese are more likely to be associated with cardiovascular events.
    CONCLUSION: BPV is associated with an increase in CVD events even in those who have achieved lower mean SBP. Thus, we should prioritize not only control of SBP levels but also BPV to reduce CVD events further.
    Matched MeSH terms: Retrospective Studies
  16. Ang CYS, Chiew YS, Wang X, Ooi EH, Nor MBM, Cove ME, et al.
    Comput Methods Programs Biomed, 2023 Oct;240:107728.
    PMID: 37531693 DOI: 10.1016/j.cmpb.2023.107728
    BACKGROUND AND OBJECTIVE: Healthcare datasets are plagued by issues of data scarcity and class imbalance. Clinically validated virtual patient (VP) models can provide accurate in-silico representations of real patients and thus a means for synthetic data generation in hospital critical care settings. This research presents a realistic, time-varying mechanically ventilated respiratory failure VP profile synthesised using a stochastic model.

    METHODS: A stochastic model was developed using respiratory elastance (Ers) data from two clinical cohorts and averaged over 30-minute time intervals. The stochastic model was used to generate future Ers data based on current Ers values with added normally distributed random noise. Self-validation of the VPs was performed via Monte Carlo simulation and retrospective Ers profile fitting. A stochastic VP cohort of temporal Ers evolution was synthesised and then compared to an independent retrospective patient cohort data in a virtual trial across several measured patient responses, where similarity of profiles validates the realism of stochastic model generated VP profiles.

    RESULTS: A total of 120,000 3-hour VPs for pressure control (PC) and volume control (VC) ventilation modes are generated using stochastic simulation. Optimisation of the stochastic simulation process yields an ideal noise percentage of 5-10% and simulation iteration of 200,000 iterations, allowing the simulation of a realistic and diverse set of Ers profiles. Results of self-validation show the retrospective Ers profiles were able to be recreated accurately with a mean squared error of only 0.099 [0.009-0.790]% for the PC cohort and 0.051 [0.030-0.126]% for the VC cohort. A virtual trial demonstrates the ability of the stochastic VP cohort to capture Ers trends within and beyond the retrospective patient cohort providing cohort-level validation.

    CONCLUSION: VPs capable of temporal evolution demonstrate feasibility for use in designing, developing, and optimising bedside MV guidance protocols through in-silico simulation and validation. Overall, the temporal VPs developed using stochastic simulation alleviate the need for lengthy, resource intensive, high cost clinical trials, while facilitating statistically robust virtual trials, ultimately leading to improved patient care and outcomes in mechanical ventilation.

    Matched MeSH terms: Retrospective Studies
  17. Chan PW, Goh AY, Chua KB, Kharullah NS, Hooi PS
    J Paediatr Child Health, 1999 Jun;35(3):287-90.
    PMID: 10404452
    OBJECTIVE: To study the viral aetiology of lower respiratory tract infection (LRTI) in young Malaysian children.

    METHODOLOGY: A retrospective review was performed of LRTI patients aged less than 24 months who were admitted to the University Malaya Medical Centre between 1982 and 1997. Respiratory viruses in their nasopharyngeal secretion were identified by indirect immunofluorescence, viral culture, or both.

    RESULTS: A total of 5691 children were included in the study. The mean age was 8.6 +/- 6.6 months and the M:F ratio was 1.6:1. The most common diagnosis was pneumonia (52%) followed by bronchiolitis (45%) and croup (2%). Positive viral isolation rate was 22.0%. Respiratory syncytial virus (RSV) was the commonest virus isolated (84%), followed by parainfluenza virus (8%), influenza virus (6%) and adenovirus (2%). Patients with positive virus isolation were younger (7.8 +/- 6.2 vs 8.7 +/- 6.7 months, P = 0.0001) and were more likely to have bronchiolitis.

    CONCLUSION: Young Malaysian children admitted with LRTI had a 22% viral isolation rate and RSV was the commonest virus isolated.

    Matched MeSH terms: Retrospective Studies
  18. Chye JK, Lim CT
    Singapore Med J, 1999 Sep;40(9):565-70.
    PMID: 10628243
    To determine the survival rates and risk factors associated with mortality in premature very low birth weight or VLBW (< or = 1500 grams) infants.
    Matched MeSH terms: Retrospective Studies
  19. Dorai AA, Halim AS, Zulmi W
    Med J Malaysia, 2004 Dec;59 Suppl F:42-6.
    PMID: 15941160
    Reconstructive surgeons often encounter complex soft tissue and skeletal defects following oncological surgery. Soft tissue defects after wide resection in upper extremities posses a difficult challenge to find adequate tissue for reconstructing these defects. Paucity of local tissues dictates the requirement of loco-regional or distant flaps for these complex soft tissue defects which often exposes tendons, bones, nerves and joints. The latissimus dorsi muscle is a near ideal flap for the reconstruction because of the long neurovascular pedicle, ease of mobilization and its expendability. It can be rotated, with or without overlying skin, to cover soft tissue defects of the shoulder arm and elbow. Due to the large size of the muscle, it can be used to resurface the soft tissue defects and cover all major structures. Eleven consecutive cases were reviewed in which latissimus dorsi myocutaneous flap was used to reconstruct soft tissue defects of the upper limb following radical tumor resection. Flap survival was 100% with nominal donor site morbidity.
    Matched MeSH terms: Retrospective Studies
  20. Chia PL, Loh SY, Foo D
    Med J Malaysia, 2012 Dec;67(6):582-4.
    PMID: 23770949
    INTRODUCTION: Ventricular tachycardia (VT) storm is an uncommon but life-threatening condition. We describe the incidence, causes and management of VT storm among patients admitted to the coronary care unit of a large tertiary hospital.

    MATERIALS AND METHODS: Between 1 November 2009 and 30 April 2010, 198 patients were admitted to the coronary care unit and 7 (3.5%) presented with VT storm. A retrospective review of their records was conducted. The mean follow-up period was 268 (196 to 345) days.

    RESULTS: The mean age was 67 years and 4 patients were male. One patient had a previous myocardial infarction. All had abnormal left ventricular ejection fraction, median of 30%. Acute myocardial infarction (4 patients) was the most common trigger, followed by decompensated heart failure (1), systemic inflammatory response syndrome on a background of non-ischemic dilated cardiomyopathy (1) and bradycardia-induced polymorphic VT (1). Three patients had polymorphic VT and the rest had monomorphic VT. Intravenous amiodarone, lignocaine, overdrive pacing and intra-aortic balloon pump counterpulsation were useful in arrhythmia control. Three patients underwent coronary revascularization, 3 patients received implantable cardioverter-defibrillators, 1 had a permanent cardiac pacemaker, 1 died during the acute episode. Five out of the 6 survivors were prescribed oral beta-blockers upon discharge. On follow-up, none of the patients had a recurrence of the tachyarrhythmia.

    CONCLUSION: Acute myocardial infarction was the main trigger of VT storm in our patients. Intravenous amiodarone, lignocaine, overdrive pacing and intra-aortic balloon pump counterpulsation were useful at suppressing VT storm.
    Matched MeSH terms: Retrospective Studies
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