ORCID Profile
0000-0003-1680-4380
Current Organisations
The Alfred Hospital
,
Monash University
,
Sengkang General Hospital
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Publisher: Medknow
Date: 28-10-2021
Abstract: INTRODUCTION Chest radiographs (CXRs) are widely used for the screening and management of COVID-19. This article describes the radiographic features of COVID-19 based on an initial national cohort of patients. METHODS This is a retrospective review of swab-positive patients with COVID-19 who were admitted to four different hospitals in Singapore between 22 January and 9 March 2020. Initial and follow-up CXRs were reviewed by three experienced radiologists to identify the predominant pattern and distribution of lung parenchymal abnormalities. RESULTS In total, 347 CXRs of 96 patients were reviewed. Initial CXRs were abnormal in 41 (42.7%) out of 96 patients. The mean time from onset of symptoms to CXR abnormality was 5.3 ± 4.7 days. The predominant pattern of lung abnormality was ground-glass opacity on initial CXRs (51.2%) and consolidation on follow-up CXRs (51.0%). Multifocal bilateral abnormalities in mixed central and peripheral distribution were observed in 63.4% and 59.2% of abnormal initial and follow-up CXRs, respectively. The lower zones were involved in 90.2% of initial CXRs and 93.9% of follow-up CXRs. CONCLUSION In a cohort of swab-positive patients, including those identified from contact tracing, we found a lower incidence of CXR abnormalities than was previously reported. The most common pattern was ground-glass opacity or consolidation, but mixed central and peripheral involvement was more common than peripheral involvement alone.
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.JSS.2022.01.013
Abstract: Despite preoperative optimization, hemodynamic instability can be a major challenge during adrenalectomy. Even brief episodes of intraoperative hypotension can be associated with ischemia-reperfusion injury. This study aimed to compare intraoperative hemodynamic parameters between posterior retroperitoneoscopic adrenalectomy (PRA) and transperitoneal laparoscopic adrenalectomy (TPA). This is a retrospective study of patients undergoing PRA and TPA without conversion or concomitant intraabdominal pathology from 2008 to 2019. The primary outcome was intraoperative hypotension defined by mean arterial pressure <60 mm Hg or the need for ≥1 intravenous vasopressors at least 30 min after anesthetic induction. Overall, 108 patients met the inclusion criteria 33 (30.6%) had pheochromocytoma, 26 (24.1%) had aldosterone excess, 8 (7.4%) had corticosteroid excess, and 41 (38.0%) had nonfunctioning adrenal tumors. Of these, 68 (63.0%) underwent PRA and 40 (37.0%) underwent TPA. Age, sex, body mass index, preinduction blood pressure, number of preoperative antihypertensives, and histopathological diagnosis were similar in the two groups. Tumor size was greater in the TPA group. The presence of pheochromocytoma was an independent risk factor for hypotension. Multivariate analysis revealed that PRA was associated with a higher risk of experiencing a mean arterial pressure <60 mm Hg (odds ratio 4.44, 95% confidence interval 1.27-15.54, P = 0.02) and the need for ≥1 intravenous vasopressors (odds ratio 9.97, 95% confidence interval 3.34-29.78, P < 0.001) compared with TPA. Although PRA offers several advantages over TPA, it carries a greater risk of intraoperative hypotension. A prospective trial is required to validate these findings. Nevertheless, institution of risk reduction strategies is encouraged to be considered for in iduals undergoing PRA.
Publisher: Elsevier BV
Date: 11-2021
DOI: 10.1016/J.EJSO.2021.06.018
Abstract: The 2015 American Thyroid Association guidelines (ATA15) consider hemithyroidectomy (HT) a viable treatment option for low-risk papillary thyroid cancers (PTCs) between 1 and 4 cm. We aimed to examine the impact of ATA15 in a high-volume Australian endocrine surgery unit. A retrospective study of all patients undergoing thyroidectomy from January 2010 to December 2019. PTC histopathology, Bethesda V-VI, size 1-4 cm, and absence of clinical evidence of lymph node or distant metastases pre-operatively. Primary outcome was rate of HT before and after ATA15. Of 5408 thyroidectomy patients, 339 (6.3%) met the inclusion criteria - 186 (54.9%) pre-ATA15 (2010-2015) and 153 (45.1%) post-ATA15 (2016-2019). The patient groups were similar there were no significant differences between groups in age, sex, tumour size, proportion with Bethesda VI cytology, compressive symptoms, or thyrotoxicosis. Post-ATA15, there was a significant increase in HT rate from 5.4% to 19.6% (P = 0.0001). However, there was no corresponding increase in completion thyroidectomy (CT) rate (50.0% versus 27.6%, P = 0.2). The proportion managed with prophylactic central neck dissection (pCND) fell from 80.5% to 10.8% (P < 0.0001). Pre-ATA15, the only factor significantly associated with HT was Bethesda V. In contrast, post-ATA15, HT was more likely in patients with younger age, smaller tumours, and Bethesda V. After the release of 2015 ATA guidelines, we observed a significant increase in HT rate and a significant decrease in pCND rate for low-risk PTCs in our specialised thyroid cancer unit. This reflects a growing clinician uptake of a more conservative approach as recommended by ATA15.
Publisher: Wiley
Date: 10-07-2023
DOI: 10.1111/ANS.18597
Abstract: Endoscopic thoracic sympathectomy (ETS) is a permanent and effective treatment for primary hyperhidrosis and facial blushing however, severe compensatory sweating (SCS) remains a devastating complication. We aimed to (i) construct a nomogram to predict the risk of SCS, and (ii) investigate factors associated with the level of satisfaction. From Jan 2014 to Mar 2020, 347 patients underwent ETS by a single surgeon. These patients were asked to complete an online questionnaire regarding primary symptom resolution, level of satisfaction, and development of compensatory sweating. Multivariable analysis was conducted via logistic regression and ordinal regression to predict SCS and satisfaction level respectively. Nomogram was developed based on significant predictors. In total, 298 (85.9%) patients responded to the questionnaire with a mean follow up of 4.9 ± 1.8 years. Significant factors associated with SCS in the nomogram included older age (OR 1.05, 95% CI 1.02–1.09, P = 0.001), primary indication other than palmar hyperhidrosis (OR 2.30, 95% CI 1.03–5.12, P = 0.04), and current smoking (OR 5.91, 95% CI 2.46–14.20, P 0.001). The area under receiver operating characteristic curve was 0.713. Multivariable analysis revealed that longer follow up ( β = −0.201 ± 0.078, P = 0.01), gustatory hyperhidrosis ( β = −0.781 ± 0.267, P = 0.003), primary indication other than palmar hyperhidrosis ( β = −1.524 ± 0.292, P 0.001), and SCS ( β = −3.061 ± 0.404, P 0.001) were independently associated with a lower degree of patient satisfaction. The novel nomogram can provide a personalized numerical risk estimate to assist both the clinician and patient weigh the pros and cons as part of the decision‐making process, mitigating the chance of patient dissatisfaction.
Publisher: Unpublished
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 09-09-2019
DOI: 10.1007/S00268-019-05153-1
Abstract: Indeterminate fine-needle aspiration cytology (FNAC) imposes challenges in the management of thyroid nodules. This study aimed to examine whether preoperative anti-thyroid antibodies (Abs) and TSH are indicators of thyroid malignancy and aggressive behavior in patients with indeterminate FNAC. This was a retrospective study of thyroidectomy patients from 2008 to 2016. We analyzed Abs and TSH levels, FNAC, and histopathology. Serum antibody levels were categorized as 'Undetectable', 'In-range' if detectable but within normal range, and 'Elevated' if above upper limit of normal. 'Detectable' levels referred to 'In-range' and 'Elevated' combined. There were 531 patients included. Of 402 patients with preoperative FNAC, 104 (25.9%) had indeterminate cytology (Bethesda III-V). Of these, 39 (37.5%) were malignant and 65 (62.5%) benign on histopathology. In the setting of indeterminate FNAC, an increased risk of malignancy was associated with 'Elevated' thyroglobulin antibodies (TgAb) (OR 7.25, 95% CI 1.13-77.15, P = 0.01) and 'Elevated' thyroid peroxidase antibodies (TPOAb) (OR 6.79, 95% CI 1.23-45.88, P = 0.008). Similarly, while still 'In-range', TSH ≥ 1 mIU/L was associated with an increased risk of malignancy (OR 3.23, 95% CI 1.14-9.33, P = 0.01). In all patients with malignancy, the mean tumor size was 8 mm larger in those with TSH ≥ 1 mIU/L (P = 0.03) furthermore, in PTC patients, 'Detectable' TgAb conferred a 4 × risk of lymph node metastasis (95% CI 1.03-13.77, P = 0.02). In this cohort, in indeterminate FNAC patients, Abs and TSH were associated with an increased risk of malignancy. Additionally, TgAb and TSH were potential markers of aggressive biology. As such, they may be diagnostic and prognostic adjuncts.
No related grants have been discovered for Shawn Kok.