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Biomedical subjects

K H Chan

Publications and source records attributed to K H Chan.

At least 217 records · Page 12Linked to original sources
PubMed1989

Lack of efficacy of middle-ear inflation: treatment of otitis media with effusion in children.

A randomized controlled trial was conducted to evaluate the efficacy of autoinflation of the middle ear in the treatment of otitis media with effusion. Forty-one children with middle ear effusion not responsive to antimicrobial therapy enrolled in the study. Of these subjects, 75 percent had effusion duration over 3 months. A system consisting of a disposable anesthesia mask attached to a flowmeter was used to teach children to perform autoinflation based on a modified Valsalva technique. Subjects were stratified according to their ability to achieve tubal opening as assessed by tympanometry and tubosonometry. Subjects were randomly assigned to either treatment or observation group and were followed weekly for 2 weeks; subjects in the treatment group attempted inflation three times each day for 2 weeks. Of the 19 subjects who were in the autoinflation group, only one (5.3 percent) was effusion-free at the two-week endpoint and of the 21 subjects in the control, only two (9.5 percent) were without middle-ear effusion. Autoinflation was ineffective for treatment of children with otitis media with effusion in our study.

Adolescent↗
PubMed1989

The significance of thrombocytopenia in the development of postoperative intracranial hematoma.

A group of 35 patients undergoing intracranial surgery who exhibited perioperative thrombocytopenia (platelet count less than 150,000/microliters) was studied retrospectively. Of the 35 patients, 14 (40%) developed postoperative intracranial hematomas requiring reoperation and seven (20%) died within 2 weeks after the operation. Analysis revealed that a perioperative platelet count below 100,000/microliters in a patient who failed to respond to platelet transfusions was associated with a higher risk of postoperative hematoma formation. All six patients with this profile developed postoperative hematomas. If the platelet count rose promptly from below 100,000/microliters to a normal level after platelet transfusions, the incidence of hematoma formation decreased dramatically. None of the three patients with this response developed postoperative hematoma. In patients in whom an acute drop in platelet count from the normal range to between 100,000 and 124,000/microliters occurred in the immediate perioperative period, there was a significantly higher change of hematoma formation; this finding has not hitherto been described. Of the 14 patients with this clinical course, eight developed postoperative hematoma after craniotomy for tumors and vascular lesions. This latter observation was substantiated by the fact that thrombocytopenic patients with postoperative hematomas had a greater reduction in platelet count than thrombocytopenic patients with no postoperative hematomas (p = 0.0004).

Aged↗
PubMed1989

[Continuous thoracic epidural fentanyl in postoperative pain control--a comparison of two different dosages].

We evaluate the postoperative pain relief using continuous epidural fentanyl infusion in two different dosages for thoracic and upper abdominal surgeries. A total of 21 ASA class III patients were studied. A thoracic epidural catheter was placed before surgery but pain control was begun when the patients became fully awake and complained of pain in the recovery room. Patients were divided into group A (n = 9) and group B (n = 12). Those in group A were given fentanyl 1.5 micrograms/kg in saline solution as initial dose followed by continuous infusion at a rate of 1 microgram/kg/h for 23 hours. In group B the initial dose and the maintenance dose were respectively 1.0 microgram/kg and 0.5 micrograms/kg/h. Following the initial dose, the intensity of pain was assessed hourly for a total of 24 hours using a visual analogue pain scale with scores from 0 to 10. In group A, the pain scale fell from the baseline level of 7.7 +/- 2.6 to 2.3 +/- 2.0 at the first hour while in group B it fell from 8.9 +/- 1.4 to 4.3 +/- 2.1. The pain scores following continuous infusion in groups A and B were respectively 1.3 +/- 1.5 and 2.9 +/- 1.7. Although the analgesic effect appeared to be better in group A, pain relief was satisfactory in both groups (p less than 0.01). Regarding respiratory depression, there was a greater degree of rise in PaCO2 in group A and some of the patients even had a PaCO2 value above 50 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Oral tramadol for extracorporeal shock wave lithotripsy].

Two hundred patients undergoing shock wave lithotripsy for renal calculi with the improved version of Dornier HM3 lithotripter system were randomly divided into group A and group B with 100 patients in each. Patients in group A were orally given tramadol 100 mg and lorazepam 1 mg and those in group B flunitrazepam 1 mg was given. Those in group A, who did not need supplemental medication during ESWL were subdivided in group A while those who needed an adjuvant of 100 micrograms intravenous fentanyl were subdivided in group A2. Like group A, those in group B, who did not need supplemental drug and those who needed 100 micrograms intravenous fentanyl were respectively subcategorized into groups B1 and B2. Drugs were given with 15 mL water 30 min prior to ESWL. Pre-operatively, an intravenous line and monitoring system which included noninvasive blood pressure and pulse oximeter were established. The entire course was divided into 5 stages i.e. stage I (prior to oral medication), stage II (10 min after medication), stage III (10 min following ESWL), stage IV (5 min following 100 micrograms intravenous fentanyl) and stage V (10 min after ESWL). The mean blood pressure, heart rate and SpO2, pain scale, sedation scale and side effects were recorded in various stages. The results showed that in group A 68 patients passed the ESWL smoothly (A1) and 32 patients needed supplemental fentanyl (A2). In group B 70 patients successfully underwent the ESWL (B1) while 30 patients needed supplemental fentanyl (B2). Ther were no significant changes in both groups in various stages regarding heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1988

A comparative study of amoxicillin-clavulanate and amoxicillin. Treatment of otitis media with effusion.

A double-blind randomized clinical trial was conducted at two sites comparing amoxicillin-clavulanate potassium (Augmentin) and amoxicillin trihydrate for the treatment of otitis media with effusion ("secretory otitis media"). One hundred eight subjects were randomly assigned to receive a ten-day course of either drug regimen. Clinical response was assessed at ten days and four weeks after entry. For those without middle ear effusion at four weeks, recurrence rates were measured at 8, 12, and 16 weeks after entry. At ten days following entry, 29 (51.8%) of 56 subjects in the amoxicillin-clavulanate-treated group were effusion free compared with 16 (32.0%) of 50 subjects in the amoxicillin-treated group (P = .06). At four weeks following entry, 26 (50.0%) of 50 subjects in the amoxicillin-clavulanate-treated group were effusion free compared with 23 (51.1%) of 45 subjects in the group given amoxicillin. By the 16-week visit, eight (36.4%) of 22 subjects in the amoxicillin-clavulanate-treated group who were effusion free at four weeks had recurrence of effusion, compared with 12 (63.2%) of 19 subjects in the amoxicillin-treated group. This study suggests that there was a favorable clinical response immediately following treatment in the amoxicillin-clavulanate--treated subjects as compared with those treated with amoxicillin, but this benefit was not sustained at the four-week end point.

Adolescent↗
PubMed1988

Efficacy of a new macrolide (azithromycin). For acute otitis media in the chinchilla model.

The efficacy of an investigational macrolide, azithromycin, in the treatment of acute otitis media consequent to an infection by a strain of beta-lactamase-producing Haemophilus influenzae, was evaluated using the chinchilla animal model. The results indicate that the azithromycin high-dosage (30 mg/kg/d) group has a significantly higher rate for effusion sterilization and resolution as compared with the other treatment groups. Unique pharmacokinetic properties of this investigational antimicrobial were demonstrated. Clinical trials using azithromycin for the treatment of upper respiratory tract infections, including otitis media, are warranted.

Acute Disease↗
PubMed1988

Characterisation and application of a murine monoclonal antibody specific for the serogroup C2 Salmonella.

An IgG3 murine monoclonal antibody (designated MO8) specific for the serogroup C2 Salmonella lipopolysaccharide (LPS) was generated by fusing mouse myeloma cells NS1 with spleen cells of BALB/c mice immunised with heat-killed S. manhattan. MO8 reacted with purified LPS prepared from serogroup C2 Salmonella but did not react with that prepared from other O serogroups, and its reactivity was also specifically absorbed by serogroup C2 Salmonella only. Polyacrylamide gel electrophoresis of the serogroup C2 LPS and subsequent immunoblotting with MO8 yielded multiple reactive bands giving a characteristic ladder pattern. The specificity of MO8 was further demonstrated in the slide agglutination test with 223 bacteria, of which only 25 belonging to serogroup C2 Salmonella reacted with the MO8 ascitic fluid. The specificity of MO8 makes it useful not only for the serological identification of Salmonella but also for the epitope analysis of the serogroup C2 LPS.

Agglutination Tests↗
PubMed1988

A preliminary report of long-term elimination of detectable mutans streptococci in man.

Application of an antimicrobial varnish to the teeth of 33 adult volunteers resulted in the elimination of detectable mutans streptococci from the saliva of 21 of them for a mean period of 34.6 weeks (range, 4 to 89 weeks) without additional treatment. The mean number of applications of varnish required for elimination was 3.14 (range, 1 to 5). Extensive examination of 10 subjects made free of mutans streptococci on the basis of saliva examination revealed no detectable mutans streptococci in their dental plaque. In 14 of the subjects in whom mutans streptococci were eliminated, they subsequently re-appeared after a mean period of 22.7 weeks (range, 4 to 71 weeks). Four out of the five recurrences that were treated were eliminated with only one additional varnish application. The treatment failed to provide long-term elimination of detectable mutans streptococci in 12 of the 33 treated subjects. No serious adverse reactions were observed in any of the treated subjects. The results indicate that it is possible to eliminate mutans streptococci from man in a safe and effective manner.

Adult↗
PubMed1988

Prolonged therapeutic external ventricular drainage: a prospective study.

Over a 2 1/2-year period, 34 patients underwent therapeutic external ventricular drainage with a valve-regulated system. The mean duration of drainage was 16 days. There was no incidence of ventricular infection, nor was there blockage of the ventricular catheter requiring revision. Eventually, 13 patients required ventriculoperitoneal shunts. All survivors remained free from complications after more than 6 months of follow-up. The system proved safe and reliable in patients requiring prolonged ventricular drainage.

Adolescent↗
PubMed1988

Intraventricular haematoma: management of comatose patients with valve regulated external ventricular drainage.

Over a 2-year period, 22 consecutive comatose patients (Glasgow Coma Score of less than or equal to 8) with intraventricular haematomas were managed with prolonged external ventricular drainage via an external one-way valve regulated system. The mean duration of drainage was 12 days. The overall mortality was 23%. According to the Glasgow Outcome Scale, 36% had severe to moderate disability and 41% made good recovery. Mortality and morbidity were closely related to the type of intraventricular haematoma and patients' preoperative clinical state. Drainage related complications: infection, and ventricular catheter blockage requiring revision, were not observed as a result of this technique. Of the survivors, nine eventually required ventriculoperitoneal shunts. Sump and valve regulated external ventricular drainage is, therefore, a useful procedure in the management of patients with extensive intraventricular haematoma.

Adolescent↗
PubMed1988

The effect of postoperative collateral ligament laxity in total knee arthroplasty.

Forty-seven patients who had been treated by 63 total knee arthroplasties were assessed at 12-84 months after the operation. The data were analyzed to determine if collateral ligament laxity had a detrimental effect on the clinical outcome. The Hospital for Special Surgery (HSS) score was used to make the clinical assessment and a modified HSS score, which excluded points awarded for laxity, was also used. Unidirectional (varus or valgus) and total (varus and valgus) laxity were used as a basis of analysis. None of the examined parameters produced results suggesting that lax knees were worse than stable knees. Indeed, knees with increasing laxity through the categories of mild and moderate showed better statistically significant results in HSS score and pain than those with lesser degrees of laxity. Seventy-five percent of the knees with unidirectional laxity were classified as excellent; only 38.5% of the stable knees were graded as excellent (p less than 0.01). Only 9% of the lax knees had complaints of pain; 38% of the stable knees were painful (p less than 0.05). No significant difference in functional score and walking ability was noted between the lax and the stable knees. Seventy-eight percent of the lax knees had a range of motion over 100 degrees; 62.5% of the stable knees achieved this range.

Adult↗