Admission triage tool for adult intensive care unit admission in Hong Kong during the COVID-19 outbreak.

Intensive care is expensive, and the numbers of intensive care unit (ICU) beds and trained specialist medical staff able to provide services in Hong Kong are limited. The most recent increase in coronavirus disease 2019 (COVID-19) infections over July to August 2020 resulted in more than 100 new cases per day for a prolonged period. The increased numbers of critically ill patients requiring ICU admission posed a capacity challenge to ICUs across the territory, and it may be reasonably anticipated that should a substantially larger outbreak occur, ICU services will be overwhelmed. Therefore, a transparent and fair prioritisation process for decisions regarding patient ICU admission is urgently required. This triage tool is built on the foundation of the existing guidelines and framework for admission, discharge, and triage that inform routine clinical practice in Hospital Authority ICUs, with the aim of achieving the greatest benefit for the greatest number of patients from the available ICU resources. This COVID-19 Crisis Triage Tool is expected to provide structured guidance to frontline doctors on how to make triage decisions should ICU resources become overwhelmed by patients requiring ICU care, particularly during the current COVID-19 pandemic. The triage tool takes the form of a detailed decision aid algorithm based on a combination of established prognostic scores, and it should increase objectivity and transparency in triage decision making and enhance decision-making consistency between doctors within and across ICUs in Hong Kong. However, it remains an aid rather than a complete substitute for the carefully considered judgement of an experienced intensive care clinician.

Feasibility of photon-counting spectral CT in dental applications-a comparative qualitative analysis.

PURPOSE: The goal of this study was to demonstrate the feasibility of using photon-counting spectral CT for dental applications. This paper qualitatively analyzes the visibility of accessory canals (ACs) and metal artefacts from dental implants for cone-beam CT (CBCT), microtomography (microCT), and photon-counting spectral CT (PCSCT). MATERIALS AND METHODS: All of the teeth in this study were extracted, and eight teeth in total were scanned on a CBCT scanner, a microCT scanner and on a PCSCT scanner. Six of the teeth that were scanned have accessory canals, one has a titanium rod attached to it, and one has a gutta-percha point inside it. Qualitative analysis was done to compare the different imaging modalities. RESULTS: The subjective image analysis demonstrated similar performance in AC detection and visualisation for PCSCT and CBCT (p value >0.05). Both PCSCT and microCT performed similarly for metal artefact reduction, and both were superior to CBCT (p value <0.05). CONCLUSION: Although microCT provides detailed information about small anatomical structures, it is not suitable for in vivo use. However, the PCSCT scanner was able to detect small anatomical structures in teeth comparable to CBCT, as well as being superior in reducing metal artefacts from dental implants. This study showed that PCSCT is a promising modality for future dentistry applications.

Disruptive Innovation in Dentistry: What It Is and What Could Be Next.

Dentistry is a technically oriented profession, and the health care sector is significantly influenced by the ubiquitous trend of digitalization. Some of these digital developments have the potential to result in disruptive changes for dental practice, while others may turn out to be just a pipedream. This Discovery! essay focuses on innovations built on artificial intelligence (AI) as the center-technology influencing 1) dental eHealth data management, 2) clinical and technical health care applications, and 3) services and operations. AI systems enable personalized dental medicine workflows by analyzing all eHealth data gathered from an individual patient. Besides dental-specific data, this also includes genomic, proteomic, and metabolomic information and therefore facilitates optimized and personalized treatment strategies and risk management. Based on the power of AI, the triangular frame of "data"/"health care"/"service" is supplemented by technological advancements in the field of social media, Internet of things, augmented and virtual reality, rapid prototyping, and intraoral optical scanning as well as teledentistry. Innovation continues to be critical to tackle dental problems until its routine implementation based on sound scientific evidence. Novel technologies must be viewed critically in relation to the cost-benefit ratio and the ethical implications of a misleading diagnosis or treatment produced by AI algorithms. Highly sensitive eHealth data must be handled responsibly to enable the immense benefits of these technologies to be realized for society. The focus on patient-centered research and the development of personalized dental medicine have the potential to improve individual and public health, as well as clarify the interconnectivity of disease in a more cost-effective way.

Is there a difference between the thicknesses of the rami in mandibular asymmetry?

The purpose of this retrospective study was to investigate whether the thicknesses of the two rami differ in patients with mandibular asymmetry. Preoperative cone beam computed tomography scans of 78 patients with mandibular asymmetry were assessed for ramus thickness, mandibular length, and mandibular shift. The results showed that the ramus was thinner on the longer side than on the shorter side in 85.9% of the patients. On average, the longer side of the mandible was 2.74mm longer (range 0.07-9.90mm, standard deviation 1.92mm) and 0.55mm thinner (range -0.61 to 2.02mm, standard deviation 0.59mm) than the shorter side (both P<0.001). This study indicates a trend in the discrepancy in ramus thickness between the longer and shorter side of about 8% of the mean thickness of the ramus. Regression analysis showed that for every 1-mm increase in the length of the mandible, the thickness of the superior aspect of the ramus was reduced by 0.041 mm (P=0.009) and the anterior aspect by 0.125 mm (P=0.001). Age and sex did not have a significant influence on the thickness of the mandible. It is concluded that the longer side of the mandible tends to be thinner at the ramus than the shorter side in patients with mandibular asymmetry. The implication of this finding could be important in relation to the sagittal split ramus osteotomy.

Bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy: a long-term analysis.

A residual bone defect at the distal aspect of the adjacent second molar may occur after total removal of the lower third molar. Lower third molar coronectomy has been proved to be a safe alternative to total removal, but the extent of bone regeneration at the adjacent tooth after coronectomy is not well reported. The aim of this prospective study was to investigate the long-term bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy. Preoperative and postoperative cone beam computed tomography scans were measured to assess bone regeneration at the distobuccal (DB), mid-distal (MD), and distolingual (DL) aspects of the lower second molar. Forty-eight coronectomies in 37 patients (23 female) with a mean±standard deviation age of 29.1±7.2 years were assessed. The mean follow-up was 93.2±8.7 months. The mean bone level increase at DB, MD, and DL aspects was 3.2±1.6mm, 3.5±1.5mm, and 3.2±1.6mm, respectively; the bone levels were significantly higher than the preoperative measurements (P<0.001). Age and impaction patterns were not factors affecting bone regeneration. Based on this study, it appears that coronectomy of the lower third molar brings favourable bone regeneration at the distal aspect of the adjacent second molar.

Sex differences in brain responses to food stimuli: a meta-analysis on neuroimaging studies.

The aims of the current study were to update the inclusion list of relevant neuroimaging studies, meta-analyse the neuroimaging data and thus synthesize a brain map showing locations with differential activations between men and women. Published studies to 2017 were retrieved and included into the analysis if they evaluated patients' brain responses to food or eating stimuli with functional magnetic resonance imaging or positron emission tomography and reported activation differences between the sexes in the form of brain coordinates based on whole-brain analysis. Eight studies that comprised a total of 231 participants fulfilled the inclusion criteria. Men had larger neural responses to food stimuli than women in the anterior and middle cingulate, which are related to emotion regulation. Meanwhile, women had larger neural responses to food stimuli than men in the parahippocampus, the thalamus and the precuneus, which are collectively relevant in the context of promotion of eating. The differential brain responses to food or eating stimuli between men and women may shed light on the neurobiology to help explain the sex differences in eating behaviour.

Three-dimensional radiographic evaluation of root migration patterns 4-8.5 years after lower third molar coronectomy: a cone beam computed tomography study.

This prospective study in patients with a follow-up of 4-8.5years aimed to describe the long-term, three-dimensional changes of coronectomized lower third molar roots. Pre- and postoperative cone beam computed tomography (CBCT) scans were compared. The distance of root migration, the direction of root translation and rotation, and the amount of bone regeneration at the adjacent second molar and superficially to the third molar root were recorded. Age, gender, time elapsed following surgery, the status of the retained root including, impaction pattern and depth of impaction were tested to check if they were influencing factors for the above outcomes. A total of 57 coronectomized third molars from 44 patients were included. The distance of the mean root migration was 2.82mm, and they predominantly translated mesially (76.8%). Age negatively correlated with the distance of migration. Root remnants with a soft tissue coverage had less bone regenerated at the adjacent second molar (1.27mm vs. 2.95mm) in comparison to their impacted counterparts. Based on the present radiographic results and the absence of any pathological findings, coronectomy can be recommended for selected cases of third molar removal as a safe procedure with favourable long-term outcomes.

Small bowel enema use in an Asian population: our eleven years of local experience.

OBJECTIVE: To retrospectively analyse the outcome of patients who underwent investigation by small bowel enema in a local centre. DESIGN: Case series. SETTING: Regional hospital, Hong Kong. PATIENTS: All patients referred for small bowel enema in a local hospital from 1 January 1999 to 31 December 2009 were identified; respective findings from imaging and clinical records were reviewed. RESULTS: A total of 341 patients were referred for small bowel enema, of whom 289 successfully completed the examination. There were 211 patients whose small bowel enema findings were considered normal and 78 were regarded as abnormal. The sensitivity of this investigation was 73% and its specificity was 91%. The respective positive and negative predictive values were 66% and 93%. CONCLUSIONS: The selection of patients by clinicians with specific indications for small bowel enema is essential for making effective use of small bowel enema as an investigative tool.

The inverse effects of load transfer and load sharing on axial compressive stiffness.

BACKGROUND CONTEXT: The goal of spinal instrumentation is to stabilize involved motion segments while fusion occurs. Although some degree of load sharing is necessary for fusion, the ability of the instrumentation system to transfer the load may vary. PURPOSE: The purpose of this study is to formulate a mathematical relationship between load sharing and load transfer of specific spinal instrumentation systems using a well-accepted mechanical model. STUDY DESIGN/SETTING: Forty-eight American Society for Testing Materials standard ultra high molecular weight polyethylene cylinders were used as per designation F 1717-96, standard test methods for static and fatigue for spinal implant constructs in a corpectomy model. METHODS: Twenty-four spinal assemblies consisting of anterior plates, anterior rod, and posterior rods were subjected to compression bending tests using a MTS Bionix servo-hydraulic material testing apparatus. Each implant was tested in compression bending with and without the addition of a titanium load-sharing cage. The force applied was the independent variable, and the displacement was the dependent variable. The stiffness was determined for each setup with and without the addition of an anterior load-sharing cage. RESULTS: The average axial compressive stiffness of a system increased by a factor of 8.5 with the addition of the load-sharing cage. An inverse relationship existed between the compressive stiffness of the construct and its relative increase achieved with the addition of the load-sharing cage. The compressive stiffness of the system with the addition of the load-sharing cage approached that of the anterior device itself as the system flexibility increased. The ability of instrumentation systems to load share or load transfer and their respective stiffness was determined. CONCLUSIONS: The 5-mm rod screw posterior system was compared with the 7-mm Ti posterior system with the addition of one and two devices for transverse traction (DTTs). The rods with the increased diameter had a stiffness of 1723 n/mm with one DTT and 1815 n/mm with two DTTs. The addition of an anterior cage had little effect on the stiffness of these systems. Anterior plate and screw/rod systems were analyzed and showed similar mechanical behavior to the 5-mm posterior rod/screw systems. A significant increase in stiffness was realized with the addition of an anterior cage. A means to determine the load sharing/transferring properties of a spinal instrumentation system is presented. This technique will allow the amount of load transferred from the fusion mass to the instrumentation to be predicted.

Occipital screw pullout strength. A biomechanical investigation of occipital morphology.

STUDY DESIGN: A three-group design with consistent pullout strength measures. OBJECTIVES: To determine pullout strength of three fixation types (unicortical screws, bicortical screws, wires) and to investigate their correlation with respect to occipital morphology. SUMMARY OF BACKGROUND DATA: A secured, multidirectional occipitocervical fusion requires internal fixation. Devices secured at occipital protuberance were suggested to offer the greatest pullout strength because of this region's thickness. METHODS: Twelve fresh human cadaveric occiputs were sketched with a grid delineating 21 fixation sites. Each site was drilled and hand-tapped. Four specimens were instrumented with unicortical screws on one side of the midline and bicortical screws on the other. Another four were instrumented with bicortical screws and wires, and the remaining four were instrumented with unicortical screws and wires. Two points on each specimen were secured with identical fixation to examine side-to-side symmetry. An MTS materials testing apparatus (MTS Systems Corporation, Eden Prairie, MN) was used to displace the fixators. Pullout strengths at different anatomic locations were recorded. RESULTS: The greatest pullout strength was at the occipital protuberance for all fixation types. The bicortical pullout strength was 50% greater than unicortical. The wire pullout strength was not significantly different from that of the unicortical screw (P > 0.05). Seventy-eight percent of wires broke at 1100 N. Unicortical pullout strength at occipital protuberance was comparable with that of the bicortical screw at other locations. CONCLUSIONS: Unicortical screw fixation at occipital protuberance offers acceptable pullout strength without the potential complications of bicortical screws or wire fixation.

Double-cycle high-dose chemotherapy with peripheral blood stem cells and hematopoietic growth factor support in patients with advanced solid tumor. A pilot study by the Hong Kong Biotherapy Group.

BACKGROUND: High-dose chemotherapy with autologous bone marrow transplantation has been useful in some patients with advanced breast, lymphoma, or germ cell tumors. Double-cycle high-dose chemotherapy may be able to deliver an even higher total dose within a given time period. It is important to determine whether peripheral blood stem cells and hematopoietic growth factors can diminish the hematopoietic toxicity of such a treatment. METHODS: From November 1989 to May 1991, 14 patients were enrolled in two cycles of high-dose chemotherapy consisting of cyclophosphamide, 4.5 g/m2; cisplatin, 150 mg/m2; and etoposide, 900 mg/m2 in each cycle. The first five patients received peripheral blood stem cells harvested from 8-10 leukaphereses during steady state. The next nine patients, besides receiving peripheral blood stem cells mobilized by growth factors, also received either granulocyte-macrophage colony-stimulating factor (GM-CSF) at 250 micrograms/m2/day by two subcutaneous (s.c.) injections given 12 hours apart from day 6 until neutrophil recovery or granulocyte colony-stimulating factor (G-CSF) at 200 micrograms/m2 as daily s.c. injections. RESULTS: For the first five patients, there was a median of 14 days from the first day of absolute marrow suppression to neutrophil count exceeding 500/microliters and a median of 15 days for a platelet count exceeding 20,000/microliters. For the next nine patients, with the use of either G-CSF or GM-CSF, there was a median of 8 days for a neutrophil count exceeding 500/microliters and and a median of 11 days for a platelet count exceeding 20,000/microliters. CONCLUSION: With the use of peripheral stem cells and growth factors, high-dose chemotherapy could be given safely every 30 days with acceptable toxicity. A high complete response rate was seen in patients with nasopharyngeal carcinoma and in patients with small cell and non-small cell lung cancer who either had not received previous chemotherapy or who had responded to previous chemotherapy.

Short-duration in vitro interleukin-2-activated mononuclear cells for advanced cancer. A Hong Kong biotherapy pilot study trial.

BACKGROUND: In vitro studies have demonstrated that a brief exposure of peripherally collected mononuclear cells to high-dose human recombinant interleukin-2(rIL-2) will generate a population of pulsed lymphokine-activated killer (LAK) cells. These cells have similar cytotoxicity against natural killer cells and resistant and sensitive target cells as compared with the standard LAK cells incubated for 3-7 days with rIL-2. Therefore, the authors conducted a pilot study to investigate the activity of pulsed LAK cells in patients with advanced cancer. METHODS: Nineteen patients were enrolled in a pilot study, and pulsed LAK cell treatment was administered two times per week for 4 weeks, followed by similar cycles if patients remained free of disease progression and unacceptable toxic effects. RESULTS: Toxic effects consisted mainly of fever, chills, nausea, and dizziness but were self-limiting and mild. Most cycles were administered on an outpatient basis. There were six partial responses (31%), occurring in two of three patients with renal cell carcinoma, two of four with hepatocellular carcinoma, one of seven with non-small cell lung carcinoma, and one of one with ovarian carcinoma. Two minimal responses were seen in one case each of melanoma and carcinoma of colon. Nine other patients had disease stabilization for 16 weeks, and two additional patients had disease progression. Phenotyping of peripheral mononuclear cells showed increases in CD56 and CD25 populations with no in vivo rIL-2 being administered after treatment with pulsed LAK cells. CONCLUSIONS: The relative ease in generating pulsed LAK cells and the associated mild toxic effects enable prolonged stimulation of the effector cells of the patients against sensitive tumor targets, with a response rate comparable to those of high-dose rIL-2 and LAK cell treatment. Therefore, it may be a theoretically ideal adjuvant for patients with renal cell carcinoma, melanoma, and hepatoma and other applicable patients after bone marrow transplantation. The initial high response rate in patients with late-stage renal cell carcinoma and hepatocellular carcinoma indicates the need for additional confirmation.