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Biomedical subjects

W S Ho

Publications and source records attributed to W S Ho.

At least 19 recordsLinked to original sources
PubMed2004

In vitro cytotoxicity testing of a nanocrystalline silver dressing (Acticoat) on cultured keratinocytes.

Acticoat is a polyethylene mesh coated with nanocrystalline silver. It has been used widely as a dressing for chronic wounds, acute partial-thickness burn wounds and donor sites. In this study, the in vitro cytotoxicity of Acticoat on cultured keratinocytes is tested. Human keratinocytes are cultivated on a pliable hyaluronate-derived membrane (Laserskin) using dermal fibroblasts as the feeder layer. When the cultured Laserskin (CLS) is subconfluent it is covered by Acticoat, which is exposed to water (Group 1), phosphate-buffered saline (Group 2) or culture medium (Group 3). The control group is not exposed to the Acticoat. After 30 minutes incubation at 37 degrees C, the inhibitory effect of the nanocrystalline silver on keratinocyte growth is measured by an MTT assay. Compared with the control, the relative viability of the CLS dropped to 0%, 0% and 9.3%, respectively. Thus, Acticoat is cytotoxic to cultured keratinocytes and should not be applied as a topical dressing on cultured skin grafts.

Bandages↗
PubMed2004

The use of pulsed dye laser for the prevention and treatment of hypertrophic scars in chinese persons.

BACKGROUND: Pulse dye laser has been used with variable degrees of success in the treatment of hypertrophic scars, and although earlier reports suggested a significant degree of improvement, more recent studies have raised concern about its effectiveness. Furthermore, most previous studies examined its use in patients with light skin types, and the use of pulse dye laser in dark-skinned patients for the treatment of hypertrophic scars is not well established. OBJECTIVE: The objective was to assess the role of pulsed dye laser therapy in the treatment and prevention of hypertrophic scars in Chinese persons. METHODS: Twenty-nine patients (35 scars) who had scars for less than 6 months were recruited into the prevention group, and 27 patients (36 scars) who had scars for more than 6 months were recruited into the treatment arm of the study. Each received pulse dye laser treatment (585 nm, 1.5-msec pulse duration, 5-mm spot size, 7-8 J/cm(2)) for three to six treatments at 8-week intervals. Half of the scar was treated with the laser and the other half was used as a control. All patients were assessed for subjective improvement with the use of a structured questionnaire and objectively with ultrasonography for thickness and a cutometer for viscoelasticity. Scars were marked on every patient and mapped with a translucent paper at the first appointment to ensure the consistency of location. At the end of the study, 15 patients from the prevention group (15 scars) and 23 patients from the treatment group (34 scars) agreed to return for spectrophotometer assessment. RESULTS: Fifty-four percent of patients in the prevention group and 66% of patients in the treatment group considered their scars to be better or much better. For both groups of patients, there was significant improvement in term of pruritics after laser treatment. For objective assessment, although scar thickness reduced significantly compared to baseline in the treatment group, such change was not significant when changes in the control side were taken into consideration. There was insignificant change in viscoelasticity. Spectrophometer assessment indicated a significant degree of lightening in the treatment group. CONCLUSION: Our study indicated that although there was significant symptomatic improvement, there was an insignificant degree of objective improvement in terms of scar thickness and viscoelasticity in the prevention group compared to the control group. Our findings are in line with several previous controlled studies and contradict the results of several others. Such differences can be due to differences in assessment methodology, laser settings, skin type, and scar location. Suprapurpuric pulsed dye laser should not be considered as the standard of practice for the treatment and prevention of hypertrophic surgical scars especially in the chest in Asians patients.

Adolescent↗
PubMed2003

Tuberculous meningitis with spinal tuberculous arachnoiditis.

This report is of a 36-year-old woman who initially presented with confusion and fever. Subsequent investigations showed tuberculous meningitis with acute hydrocephalus. Ventriculoperitoneal shunt was performed and anti-tuberculosis therapy was given. The patient was later noticed to have weakness of both lower limbs and urinary retention. Magnetic resonance imaging of the thoracic spine showed radiological features of tuberculous arachnoiditis with cord compression. Decompressive laminectomy was performed and high-dose systemic corticosteroid was given. A high level of awareness is required when diagnosing tuberculous arachnoiditis and the importance of high-dose corticosteroid in the treatment regimen is emphasised.

Adrenal Cortex Hormones↗
PubMed2002

Before the paradigm shift: concepts and communication between doctors and nurses in a burns team.

The evolution of care delivered by a multidisciplinary burns team is a function of the effectiveness of the professional communication between team members. In this exercise, we have explored concepts and communication between nurses and doctors in a burns team. Loosely structured weekly meetings were held over a 4-month period. The explicit objective was to determine and define the current model of burns care in a regional burn centre. The implicit objective, however, was to develop a mutual appreciation of actual and potential problems in communication. Consensus task identification was achieved at the end of each meeting with full compliance in completing the tasks before the next meeting. Although there was a unanimous commitment to the team concept, traditional, professional, paradigms persist. For nurses, the concept of holistic modelling predominated, whilst the disease centred paradigm remained the focus of medical modelling. Linguistic, cultural and professional barriers to effective communication were identified but did not readily conform to prior expectations. Experience in burns care can transcend these barriers more effectively than a common culture or profession. In conclusion, team work and team building is a complex process that can benefit from an ongoing process of re-evaluation. An obvious yet common error is to assume a level of mutual understanding that does not in fact exist. Stepping aside to re-explore fundamental principles on which team members base their personal and professional practice can help in elucidating and determining new paradigms of care, which can be evaluated and appropriately implemented. The consensus conclusion was that this approach was a very valuable investment in time in pursuing excellence in the field of burns care.

Attitude of Health Personnel↗
PubMed2002

Chemical assaults in Hong Kong: a 10-year review.

The aim of this study was to assess the patients admitted to Prince of Wales Hospital Burns Unit, Hong Kong between September 1991 and August 2001 following chemical assault. A total of 2319 burns were admitted during the study period of which 19 had been subjected to chemical assault. All victims sustained a burn injury to the head and neck area and 47% of victims' eyes were burnt. A total of 84% required surgical intervention. Where a reason for the attack was admitted most were due to relationship difficulties. This study has defined the victims of chemical assault in Hong Kong. At a time when the overall number of assaults in Hong Kong is at its lowest level for 5 years it is of concern that there appears to have been a recent increase in the number of chemical assaults in Hong Kong.

Adolescent↗
PubMed2002

Outcome analysis of 286 severely burned patients: retrospective study.

OBJECTIVE: To evaluate the outcomes of severely burned patients treated at a regional burns unit and to develop a predictive model for survival and length of hospital stay for major burn patients in Hong Kong. DESIGN: Retrospective study. SETTING: Burns unit of a regional public hospital, Hong Kong. PATIENTS: Two hundred and eighty-six severely burned patients treated from March 1993 to February 2000. MAIN OUTCOME MEASURES: Details of demographics, mechanism of burn, extent of burn, incidence of inhalation injury, length of hospital stay, and mortality rate were recorded and entered into a database. Stepwise logistic regression and linear regression were applied to develop a predictive model for mortality and morbidity, respectively. RESULTS: Of 286 major burn patients treated in this 7-year period, 25 patients died from their injuries, yielding a mortality rate of 8.7%. Stepwise logistic regression was applied to develop a predictive model for mortality. We found that inhalation injury, age, and total body surface area involvement were independent significant predictors of death. Accuracy of this predictive model reached 93%. Similarly, stepwise linear regression was used to develop a predictive model for length of hospital stay. Sex, inhalation injury, total body surface area of burn, and total body surface area(2) of burn were significant predictors of length of hospital stay (R(2)=0.2). Only three patients' duration of hospital stay was more than three standard deviations from the predicted length of hospital stay. CONCLUSION: A predictive model for mortality and length of hospital stay has been developed for major burn patients in Hong Kong. This model may help clinicians to counsel patients and relatives at an early stage of care, to provide a basis from which new treatment plans can be compared, and to facilitate efficient allocation of valuable medical resources.

Adolescent↗
PubMed2001

Endoscopic-assisted subcutaneous mastectomy and axillary dissection with immediate mammary prosthesis reconstruction for early breast cancer.

BACKGROUND: Endoscopic surgery has been applied successfully in breast lump excision, breast augmentation, subcutaneous mastectomy for gynecomastia, and axillary dissection. Since subcutaneous mastectomy has been proven to be oncologically safe for early breast cancer, we have sought to develop a reproducible minimally invasive endoscopic-assisted technique to address this condition. METHODS: Between December 1998 and May 1999, endoscopic-assisted subcutaneous mastectomy and axillary dissection with immediate reconstruction using a mammary prosthesis was performed in nine patients with early breast cancer at the Prince of Wales Hospital, Hong Kong. A 5-cm skin incision was made along the line of the lowest axillary skin crease. Dissection was continued down to the lateral border of the pectoralis major muscle. A subpectoral pocket was gently created by an endoscopic breast dissector. The endoscopic breast retractor and 10-mm/30 degrees scope were introduced into the subpectoral pocket, and further dissection was carried out using a 7-in harmonic scalpel under endoscopic vision down to a level 1 cm caudal to the inframammary fold. This subpectoral space was used for the insertion of the mammary prosthesis later on. Endoscopic-assisted subcutaneous mastectomy was performed afterward. Combined level I and level II axillary dissection was carried out via the same incision under direct vision. RESULTS: Apart from minor skin flap bruises in our first two patients, there were no major complications. Histological examination of all the specimens showed clear margins. Postoperative radiotherapy and chemotherapy were given in the usual manner. All patients were satisfied with the reconstructive outcome. CONCLUSIONS: We have described a novel endoscopic technique for subcutaneous mastectomy with immediate mammary prosthesis reconstruction in treating early breast cancer patient. This technique can minimize skin incision, reduce blood loss, and improve reconstructive outcome. It is easy to learn and well accepted by patients.

Adult↗
PubMed2001

Nevus of Ota: a new classification based on the response to laser treatment.

BACKGROUND AND OBJECTIVE: For 60 years, Tanino's classification has been used to classify the extent of nevus of Ota. However, such classification not only fails to address variants such as phacomatosis pigmentovascularis but also cannot be used to predict the therapeutic outcome. Our objective is to retrospectively study our series of laser-treated patients with the aim of re-classifying nevus of Ota, so that such important issues can be taken into account. STUDY DESIGN/MATERIALS AND METHODS: One hundred nineteen patients that had received Q-switched laser treatment were recruited into the study. They were recalled for interview and examination for evidence of coexisting birthmarks and extracutaneous involvement. Two observers assessed the pre- and posttreatment clinical photographs for evidence of periorbital under-response (panda's sign), defined as the degree of periorbital laser clearing significantly less than clearing in the other area. RESULTS: A total of 47.8% of the patients with periorbital pigmentation were considered by the observers to have significant periorbital under-response (panda's sign). Additionally, 10.1% had other birthmarks, and extracutaneous involvement was seen in 31.4% of the patients. CONCLUSION: Periorbital under-response is commonly seen in patients with periorbital pigmentation. Taking this and other factors into consideration, we have proposed a new classification for nevus of Ota that allows for the prediction of the clinical outcome of laser treatment.

Adolescent↗
PubMed2001

Playing with fire--a significant cause of burn injury in children.

We report our experience with 50 patients who were burned as a result of playing with fire over the period of January 1993 to December 1999. There were 43 males and 7 females with a male to female ratio of 6.1:1. The average age was 12.3+/-10.3 year with 39 (78%) patients under the age of 15. The mean extent of burn was 6.4+/-10.7% total body surface area (TBSA) and 2 children had extensive burns >30%. The burns predominantly involved the head and neck region, upper limb, hand and lower limb. There was no mortality in our series. Wax and fireworks were recognized as the two major burn causing agents in these 50 patients. Risk factors associated with these injuries as well as preventive measures were also presented.

Adolescent↗
PubMed2001

Corneal perforation with extrusion of lens in a burn patient.

The incidence of ophthalmologic injuries has been reported to be between 20 and 25% in all the burn patients. As most of the eye injuries are associated with severe burns, attention is often directed towards the life-threatening events and eye injuries may be overlooked and undertreated. This case report presents a patient who had 40% flame burn and had recently been transferred from another hospital. He was examined by an ophthalmologist at the referring hospital and it was documented that both of his eyes were normal. He was transferred into the Burns Unit at the Prince of Wales Hospital 8 h later. Unfortunately, all the attention was directed to save his life and it was not until post-burn day 11 that he was found to have right corneal ulceration. Despite vigorous ophthalmologic treatment, the cornea perforated 2 days later with subsequent extrusion of the lens. In view of his grave prognosis with multi-organ failure, he was treated conservatively and he died the following day. It is mandatory to refer patients with facial burns to the ophthalmologist for ocular examination. We recommend that serial eye examinations should be carried out in burn patients who are unconscious or intubated for ventilatory support even if the initial ophthalmologic examinations are normal as the potential risk of serious ocular injuries are high in this particular group of patients.

Aged↗
PubMed2001

Suicidal burns in Hong Kong Chinese.

There were 1063 acute burn patients admitted to the Burns Unit of Prince of Wales Hospital, Hong Kong, between March 1993 and February 1999. Eleven patients (1%) were burned due to attempted suicide. Seven were males and four were females, with a male:female ratio of 1.75:1. The median age was 38 years (range: 20-49 years) and the median extent of the burns was 55% total body surface area (range: 1-95%). Ten patients (90.9%) were self-incinerated and one patient attempted suicide by jumping into a hot bath. Seven patients (63.6%) suffered from severe smoke inhalation injury that required immediate intubation for ventilatory support. The average number of operations for the survivors was 3.7 (range: 0-8) and their median hospital stay was 42 days (range: 2-92 days). Four patients (36.4%) died from their injuries. Suicidal burns were more common among unemployed males with a history of psychiatric illness and substance abuse. Town gas (naphtha: a mixture of 49% hydrogen, 28.5% methane, 19.5% carbon dioxide and 3.0% carbon monoxide) was the most frequently used agent for self-immolation because it is probably the most convenient source of a fire accelerant in Hong Kong. Compared to the general burn population, this suicide group had a larger extent of burns, higher incidence of inhalation injury, required more operative treatment and longer hospital stay with a higher mortality rate.

Adult↗
PubMed2001

An epidemiological study of 1063 hospitalized burn patients in a tertiary burns centre in Hong Kong.

A total of 1063 acute burn patients were admitted to the Burns Unit of Prince of Wales Hospital, Hong Kong between March 1993 and February 1999. There were 678 males and 385 females with a male to female ratio of 1.76:1. The median age was 13.1 year-old and the median burn size was 6% total body surface area (TBSA). Pediatric patients under the age of 15 year-old accounted for 550 (51.7%) admissions and 235 (42.7%) of them were toddlers <2 year-old, while adult patients of age above 15 year-old accounted for the other 513 (48.3%) admissions. There was no seasonal variation in admission. Domestic burns resulted in 756 (71.1%) injuries followed by industrial burns that caused 175 (16.5%) admissions. The median hospital stay was 9 days and 54 patients (5.1%) had inhalation injury requiring intubation and ventilatory support. Twenty-four patients died in this series which yielded a mortality rate of 2.3%. The median age for this mortality group was 46.6 year-olds with a median extent of burns of 68% TBSA. There were 16 males and 8 females with a male to female ratio of 2:1. Eighteen (75%) patients had flame burns and 15 (83.3%) of them had inhalation injury. The mortality group had significantly larger burn size (P<0.001), higher incidence of inhalation injury (P<0.001) and older age (P<0.001) compared to the survivors.

Adolescent↗
PubMed2001

A study of burn injuries in the elderly in a regional burn centre.

We evaluated the epidemiology and outcome of 94 elderly burn patients of age 60 years or older treated in a local burn centre over a period of 6 years. There were 44 males and 50 females with a male to female ratio of 0.88 and an average age of 73.8+/-9 years. The mean extent of burn was 13.3+/-18.4% total body surface area (TBSA) with 14 patients (15%) suffering from a burn size >20% TBSA. The vast majority of injuries (90%) occurred at home. Scalds resulted in 62 admissions (66%) and flame burns accounted for another 29 admissions (31%). The burns predominantly involved the extremities and the trunk. Four patients had inhalation injuries and required admission to the Intensive Care Unit for ventilatory support. The majority of patients (60%) did not require any operations. The mean hospital stay of the survivors was 30.1+/-34.1 days and 35% of them stayed less than 2 weeks. Fifty-five patients (59%) had at least one pre-existing medical problem requiring long-term medication and 41 patients (44%) were living alone. Sixty-three patients (67%) presented more than 8 h after the burn injuries and 34 patients (36.2%) had no first aid treatment of their burn wounds. In addition, 40 patients (42.5%) had their wounds treated inappropriately. Seven patients died in this series which yielded a mortality rate of 7.4%. The outcomes of early versus late excision and grafting were also analyzed.

Aged↗
PubMed2001

Contact burn by charcoal in an attempted suicide.

A 23-yr-old lady was inadvertently burned during an attempted suicide. After quarrelling with her boyfriend, she attempted to commit suicide by using alcohol, benzodiazepine and burning charcoal within her sealed bedroom. Her left leg fell over the edge of the bed while she was half-conscious, that resulted in direct contact with the hot pot causing 1% full thickness burn and burn of her left tibialis anterior and extensor digitorum longus. She was initially resuscitated with 100% oxygen and gastric lavage and subsequently was managed in the Burns Unit for wound care, surgical debridement of the burn wound and skin graft, and psychological support. Burning charcoal in a sealed room is an emerging form of suicide in Hong Kong and this is the first case complicated by a burn wound in our locality. A holistic approach to tackle the bio-psycho-social aspects of individual's problem is advocated.

Adult↗
PubMed2001

Assault by burning--a reappraisal.

Assault by burning is a serious form of trauma that often results in higher incidence of inhalation injury, longer intensive care unit (ICU) and hospital stay, and higher mortality rate than is observed in the general burn population. We evaluated the epidemiology and outcome of assault burn victims treated in a tertiary burn center over a 6-year period. Among the 1063 acute burn patients who had been admitted to the Burns Unit between March 1993 and February 1999, 28 (2.6%) had assault burn injuries either by scald, chemical or fire. The mean extent of burn was 21.9%+/-20.8% (range 2-90%) total body surface area and the mean length of hospital stay was 65.2+/-107.3 days (range 1-565). Nineteen out of 25 patients (67.9%) underwent 76 operations. Nine patients had inhalation injuries requiring intubation and ICU admission. Three patients died in the series, which yielded a mortality rate of 10.7%. Compared to the general burn population, the assault burn group had significantly larger burn size (P<0.001), higher incidence of inhalation injury (P<0.001), longer ICU and hospital stay (P<0.001), and higher mortality rate (P<0.005). When these 28 victims were grouped according to the type of assault burn injury into a fire group, chemical group and scald group, all the 9 ICU admission and the 3 mortalities belonged to the fire group. Assault by fire resulted in larger burn size (P=0.03), more inhalation injury (P<0.001) and longer ICU stay (P=0.02). Although the fire group had a longer hospital stay and higher mortality rate, this was statistically insignificant.

Adolescent↗