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Biomedical subjects

C K Chan

Publications and source records attributed to C K Chan.

229 records · Page 13Linked to original sources
PubMed1978

Management of septic thrombosis of the inferior vena cava caused by Candida.

Septic thrombosis of central veins is rarely diagnosed during life and nearly always proves fatal. We have recently successfully treated a patient with a 75% body surface burn in whom septic thrombosis of the inferior vena cava developed associated with high-grade candidemia as a complication of parenteral nutrition. Signs of venous thrombosis and candidemia persisted after catheter removal. Prompt and intensive therapy with amphotericin B, monitored by fungicidal assays of serum, resulted in cure. Generous hydration and directed supplementation of sodium bicarbonate permitted us to administer a large total dose of amphotericin over a relatively brief period of time with no nephrototoxic effect whatsoever. Septic central venous thrombosis mandates a pharmacologic approach to therapy similar to that used for infective endocarditis, with the addition of anticoagulation. Should sepsis prove refractory to this program of it pulmonary embolization occurs, operative intervention is indicated despite the high risks involved.

Adult↗
PubMed1978

Inhalation injury--an increasing problem.

Inhalation injury is a common complication of thermal accidents occurring in one-third of patients burned. The routine use of fiberoptic bronchoscopy on all patients incurring thermal burns provides an accurate and safe means for diagnosis. Although complications for inhalation injury are common, the mortality can be reduced by early diagnosis and attention to careful fluid resuscitation, aggressive pulmonary therapy and the avoidance of prophylatic steroids.

Adolescent↗
PubMed1978

Postbacterial sepsis and disseminated candidiasis.

The effect of gram-negative sepsis (Escherichia coli) on the capacity of polymorphonuclear leucocytes (PMN) to phagocytize and kill Candida albicans was assessed. The PMN's from septic dogs phagocytized C. albicans as well as PMN's from non-septic dogs. The PMN's from septic dogs that phagocytized C. albicans underwent a spontaneous lysis at a much higher rate than PMN's from non-septic dogs. A functional difference in PMN's from normal and septic dogs is indicated.

Animals↗
PubMed1977

Proper management of hepatic adenoma associated with oral contraceptives.

Four patients with oral contraceptive associated hepatic adenoma have been studied and the literature reviewed. Clinically, these patients can be divided into ruptured and nonruptured hepatoma groups. In instances of ruptured hepatomas, resection only sufficient to control hemorrhage definitely is recommended. In instances of nonruptured hepatomas, major resection should only be attempted by skilled surgeons, and small multiple lesions should be observed. These management principles will deserve re-evaluation as more experience with these tumors accumulates. Until then, a conservative approach is indicated. This includes the avoidance of oral contraception until the biochemistry of these tumors is better clarified.

Adenoma↗
PubMed1976

Acute leukopenia as an allergic reaction to silver sulfadiazine in burn patients.

Of 68 burn patients at the University of Wisoncsin Burn Center treated with silver sulfadiazine cream over 2 years, two (about 3%) developed fever and marked leukopenia. The symptoms disappeared 1-2 days after discontinuation of the cream. The two cases are described and possible mechanisms of allergic response to this agent are discussed.

Acute Disease↗
PubMedDate not supplied

Corticosteroids and azathioprine do not prevent radiation-induced lung injury.

The case of a man who presented with dyspnea and a dry cough six weeks after mediastinal radiotherapy for malignant thymoma is described. The patient was on prednisone (30 mg/day) and azathioprine (100 mg/day) throughout the course of radiation. The respiratory difficulties developed as the dose of prednisone was gradually decreased to 20 mg/day postradiation. Chest x-ray showed bilateral pulmonary infiltrates. Computed tomography scan of the thorax confirmed bilateral ground glass opacities, with well-defined lateral margin on the right side corresponding to the field of radiation. However, the airspace opacities extended beyond the radiation field into the periphery of the lungs together with mild airway dilation on the left side compatible with bronchiolitis obliterans organizing pneumonia (BOOP) or cryptogenic organizing pneumonia. Bronchoalveolar lavage performed on the nonirradiated area showed an intense lymphocytosis. No cause of BOOP other than radiation was found. Treatment with high dose corticosteroids (80 mg/day) resulted in rapid clinical and radiological improvement, and resolution of chest x-ray abnormalities. Focal mediastinal radiation therapy may induce diffuse lung injury including BOOP. In addition, the concurrent use of moderate dose prednisone and azathioprine during the periradiotherapy period does not prevent the development of either BOOP or classic radiation pneumonitis.

Aged↗
PubMedDate not supplied

The use of guidelines for the empirical treatment of hospital-acquired pneumonia.

BACKGROUND: Several practice guidelines for the empirical antimicrobial treatment of hospital-acquired pneumonia (HAP) have been developed, but the acceptance and use of such guidelines are unknown. OBJECTIVE: To assess physicians' use of empirical HAP guidelines published by the American Thoracic Society (ATS) and by The University Health Network, Toronto, Ontario. DESIGN: A retrospective assembly and chart review. SETTING: A university teaching hospital. PATIENTS: One hundred fifteen consecutive patients who had been diagnosed with pneumonia more than 48 h after admission to hospital over a 10-month period. RESULTS: The charts of 115 patients were reviewed. Seventy-five patients (65%) were treated empirically. Forty patients (35%) were treated based on microbiological data that were available before the initiation of antibiotics. Patients who received nonempirical treatment for HAP had a significantly greater acuity of illness than the empirically treated group. Thirty-seven patients (49%) who received empirical therapy were treated according to either ATS or hospital guidelines for HAP. The use of guideline-concordant antimicrobial therapy had no measurable effect on in-hospital mortality (eight of 37 patients [21.6%] versus seven of 38 patients [18.4%], P=0.96) or median length of stay (19 days versus 21 days, P=0.30). Patients whose treatment did not follow guideline recommendations tended to receive appropriate antimicrobial coverage more often than did those patients whose treatment was guideline concordant (15 of 18 patients [83%] versus six of 11 patients [55%], P=0.49). CONCLUSIONS: Institutional and ATS guidelines for the empirical treatment of HAP are less widely used than would be predicted by chance at The University Health Network. The clinical utility of these guidelines remains to be proven.

Aged↗
PubMedDate not supplied

17-year follow-up of a randomized prospective controlled trial of adjuvant intravesical doxorubicin in the treatment of superficial bladder cancer.

PURPOSE: To evaluate the efficacy of adjuvant intravesical doxorubicin in superficial transitional cell carcinoma of the urinary bladder on long-term follow-up. MATERIALS AND METHODS: Between July 1986 and November 1991, all patients harboring superficial bladder cancers (Ta or T1) with one or more of these criteria (stage>a, grade>1, size>1 cm, multiple or recurrent tumors) were randomized to receive either 50 mg doxorubicin or no adjuvant therapy. Patients with recurrences were allowed to receive doxorubicin or other intravesical agents. Recurrence, progression and survival were analyzed. RESULTS: There were 82 patients included (64 males and 18 females). The mean age was 64 years. Forty-six patients were randomized to the doxorubicin group and 36 to the control group. Final analysis was made at median follow-up of 45, 128 and 131.5 months for recurrence, progression and survival, respectively. Recurrence free, progression free and disease specific survival did not differ significantly between groups. The 10-year Kaplan-Meier estimates for recurrence free, progression free and disease specific survival were 67%, 84% and 92%, respectively for the doxorubicin group, and were 50%, 89% and 97%, respectively for the control group. Tumor size predicted recurrence (p=0.013) and grade predicted progression (p=0.004) with multivariate analysis. CONCLUSIONS: Adjuvant intravesical doxorubicin could not be shown to improve recurrence, progression and survival of superficial bladder cancer, compared with control on long-term follow-up. Tumor size and grade were shown to be prognostic factors for recurrence and progression, respectively.

Administration, Intravesical↗
PubMedDate not supplied

Central imidazoline receptors and centrally acting anti-hypertensive agents.

We have examined the location and contribution of imidazoline receptors (IR) in mediating the hypotensive and sympatholytic actions of first and second generation anti-hypertensive agents in rabbits. We found that the hypotension produced by rilmenidine and moxonidine given intravenously (i.v.) or into the fourth ventricle (4V) was preferentially reversed by the IR antagonists idazoxan and efaroxan (compared to a selective alpha(2)-adrenoceptor antagonist 2-methoxy-idazoxan), suggesting that IR are important in the sympatho-inhibition produced by these agents. Clonidine was not preferentially reversed by the IR antagonists suggesting an action via alpha(2)-adrenoceptors. In anaesthetised rabbits, the rostral ventrolateral medulla (RVLM) was the most potent site for rilmenidine to produce the sympatho-inhibition and modulation of sympathetic baroreflexes. alpha-Methylnoradrenaline was also sympatholytic suggesting alpha(2)-adrenoceptors are also present in this site. Microinjection of the IR and alpha(2)-adrenoceptor antagonists showed that rilmenidine activates IR in the RVLM but that alpha(2)-adrenoceptors are also activated as a consequence. These studies suggest that rilmenidine acts primarily via IR in the RVLM to reduce sympathetic tone but also imply an important association of alpha(2)-adrenoceptors and IR in the region.

Adrenergic alpha-Agonists↗