PubMed Health⌕ Search

Biomedical subjects

K K Lam

Publications and source records attributed to K K Lam.

At least 37 records · Page 2Linked to original sources
PubMed1997

Transdermal fentanyl for severe cancer-related pain.

A prospective phase II study was conducted to define the analgesic efficacy, acceptability and toxicity of the transdermal therapeutic system (TTS) of fentanyl in Chinese patients with severe cancer-related pain. A total of 14 patients was treated with TTS fentanyl at doses ranging from 25 to 100 micrograms h-1; initial doses were chosen according to their previous opioid requirement. Standard supportive therapy was given as required. A brief pain inventory (using a 10-point scale) was used to assess patients at days 0, 7 and 14. Pain control on day 14 with TTS fentanyl was successful in six patients, with a reduction in the common side-effects of other opioids and improvement in general well-being. Seven patients did not complete the 14-day trial: two developed dizziness and nausea within 3 h of application; and in five, TTS fentanyl was insufficiently flexible to control increasing pain during the first week. TTS fentanyl was effective and well tolerated in 43% of patients. Acute dizziness and nausea within the first few hours after application and the relative inflexibility of dose-adjustment both limited the use of TTS fentanyl.

Administration, Cutaneous↗
PubMed1997

Comparison of patient-controlled epidural analgesia with patient-controlled intravenous analgesia using pethidine or fentanyl.

We compared patient-controlled epidural analgesia (PCEA) with patient-controlled intravenous analgesia (PCIA) using pethidine or fentanyl in a randomized, double-blind crossover study of 80 patients after caesarean section. Patients received pethidine by PCEA or PCIA, or fentanyl by PCEA or PCIA, with a crossover of the route of administration at 12h. For pethidine, pain scores were lower with PCEA vs PCIA from 4 to 16h (P < 0.05). Pethidine consumption was lower with PCEA vs PCIA from 12 to 24h (P = 0.0005). Patients preferred PCEA to PCIA (P = 0.015). For fentanyl, pain scores were lower with PCEA vs PCIA at 12h (P = 0.045). Fentanyl consumption was lower with PCEA vs PCIA from 0 to 12h (P = 0.0007). Patients had similar preference for PCEA and PCIA. Pain scores and side-effects were similar between drugs. Plasma pethidine was similar between groups. Plasma fentanyl was higher with PCIA vs PCEA at 12h (P = 0.002). PCEA has advantages over PCIA and pethidine may be the preferred drug.

Analgesia, Epidural↗
PubMed1996

No subacute thrombosis and femoral bleeding complications under full anticoagulation in 150 consecutive patients receiving non-heparin-coated intracoronary Palmaz-Schatz stents.

Intracoronary stenting has been shown to have better immediate and long-term clinical outcomes and less restenosis than standard balloon angioplasty. However, the benefit was achieved at the cost of higher rates of coronary thrombosis, bleeding complications, the need for anticoagulation, and longer hospital stay. For the latter reasons there is a tendency to replace the anticoagulants by antiplatelet agents alone after stenting. However, we prospectively monitored 150 consecutive patients (133 men, 17 women, mean age 58.5 years) from two centers since February 1993. They all had coronary artery disease and underwent percutaneous implantation of non-heparin-coated Palmaz-Schatz coronary stents under a full but lower dose of anticoagulation. The femoral approach was used in all patients except one. In the 150 patients, 200 stents were implanted in 165 target arteries with 172 lesions. Stenting was performed without the guidance of intravascular ultrasonography; high-pressure poststenting inflation was used in only 17.3% of patients with less than optimal angiographic results. Coronary angiography was performed at baseline, immediately after the procedure, and after 6 months (mean 207 +/- 53.6 days SD) of stenting. The mean (+/-SD) coronary minimum luminal diameter increased from 0.52 0.31 mm to 3.13 +/- 0.42 mm immediately after stenting was performed and was 2.12 +/- 0.91 mm at 6 months. There was a 0% subacute thrombosis rate and a 0% femoral bleeding complication rate in the whole series. Only three (2%) major events occurred: one Q-wave myocardial infarction from closure of an angioplasty site distal to the stent on a very long lesion, one cerebrovascular accident, and one noncoronary-related death. The only patient who underwent the brachial approach had hematoma; otherwise no other minor event occurred. The mean hospital stay was 4.5 days in one of the two study centers. The long-term clinical follow-up rate was 97.3%. The mean (+/- SD) clinical follow-up period was 589 +/- 363 days. Clinical symptoms improved; the percentage of patients who had angina according to the Canadian Cardiovascular Society functional class II, III, and IV was 31.3%, 44.7%, and 4%, respectively, before stenting was performed and was reduced to 4.7%, 3.7%, and 0%, respectively at 6-month follow-up after stenting was performed. The 6-month angiographic restudy rate was 90.6%, and the restenosis rate was 18.3%. In contrast to other reported series, these results support the idea that with careful puncture technique and meticulous postoperative wound care, intracoronary stenting can be successfully performed with the patient under full anticoagulation without major risks of bleeding and femoral vascular complications. Furthermore with a full but comparatively lower dose of anticoagulation, subacute thrombotic complications can be reduced to 0% even with non-heparin-coated stents without the use of intravascular ultrasound guidance and without the use of adjunctive high-pressure poststenting inflation in most patients. The restenosis rate and long-term clinical outcomes remained very favorable.

Acute Disease↗
PubMed1996

Epidural meperidine after cesarean section. A dose-response study.

BACKGROUND: Epidural meperidine is effective for postoperative analgesia, but the optimum dose has not been evaluated. METHODS: Five doses of epidural meperidine (12.5, 25, 50, 75, and 100 mg) given at the first request for analgesia after cesarean section were compared. Visual analog pain scores, duration of analgesia as defined by time to first patient-controlled epidural analgesia demand, plasma concentrations of meperidine, side effects, and subsequent 24-h consumption of meperidine were evaluated. RESULTS: All doses were effective, but patients took longer to become pain-free after 12.5 mg (median 30 min) compared with 25 mg (median 12 min, P = 0.038), and duration of analgesia was shorter after 12.5 mg (median 83 min) compared with 25 mg (median 165 min, P = 0.0005). Increasing dose to more than 25 mg did not improve onset or duration of analgesia. Plasma concentrations of meperidine were less than minimum effective analgesia concentration for all doses except 100 mg. There was more frequent nausea (P = 0.004) and dizziness (P = 0.0002) after 100 mg compared with smaller doses. CONCLUSIONS: Epidural meperidine provides effective postoperative analgesia, although of relatively short duration. A single dose of 25 mg is superior to 12.5 mg, but there is no benefit from increasing the dose to 50 mg or greater.

Adult↗
PubMed1996

Evaluation of a disposable device for patient-controlled epidural analgesia after caesarean section.

We evaluated a disposable device (Baxter PCA Infusor) for patient-controlled epidural analgesia (PCEA) using pethidine in twenty women after lower segment caesarean section. Efficacy, as measured by visual analogue pain scores, was comparable with historical controls from PCEA studies using electronic devices. Three patients reported inadequate analgesia, attributable in two cases to problems with epidural catheter. PCEA was stopped in one patient because of side-effects. Pethidine consumption ranged from 125 to 1500 mg (median 575 mg) in 48 hours. Plasma concentrations of pethidine varied widely. Disposable devices for PCEA after caesarean section provide an alternative to bolus administration or PCEA using more expensive and cumbersome electronic devices, although we suggest currently available apparatus requires modifications to improve clinical performance.

Adult↗
PubMed1996

[Clinical experience of automated double filtration plasmapheresis].

Double filtration plasmapheresis, one kind of fractionation plasmapheresis, was developed from membrane type plasmapheresis to remove only the pathogen and return the normal protein back to the patient. We started our automated double filtration plasmapheresis since December 1993. There were 13 patients who received one hundred treatments totally during one year period. And they are myasthenia gravis (8 patients); acute inflammatory demyelinating polyneuropathy (1 patient), multiple myeloma (1 patient); acquired factor VIII inhibitor (1 patient); autoimmune hemolytic anemia (1 patient); systemic lupus erythematous (1 patient). Technically double filtration plasmapheresis is easy to perform and time-saving. It also makes necessity of replacement fluid less frequent. Incidence of complication is rare, and this includes hypotension 2%, palpitation 1%, headache 1%, hemolysis 4%, air emboli 1%, high secondary pressure 2%, and no motality during our treatment. Clinical response is documented in cases of myasthenia gravis; acute inflammatory demyelinating polyneuropathy and acquired factor VIII inhibitor in our study. In conclusion, double filtration plasmapheresis is a time-saving, convenient, and safe therapeutic modality with rare complication. Because its effectiveness on limited kinds of diseases and costs relatively high price, thus plasmapheresis should be used in selected cases and treat aggressively if indicated.

Adolescent↗
PubMed1995

A new platelet-derived growth factor-regulated genomic element which binds a serine/threonine phosphoprotein mediates induction of the slow immediate-early gene MCP-1.

The MCP-1 chemokine gene belongs to a cohort of immediate-early genes that are induced with slower kinetics than c-fos. In this study, we identified a cluster of four platelet-derived growth factor (PDGF)-responsive elements within a 240-bp enhancer found in the distal 5' flanking MCP-1 sequences. Two of the elements bind one or more forms of the transcription factor NF-kappa B. We focused on the other two elements which are hitherto unreported, PDGF-regulated genomic motifs. One of these novel elements, detected as a 28-mer by DNase I footprinting, restores PDGF inducibility when added in two copies to a 5' truncated MCP-1 gene. A single copy of the second novel element, a 27-mer, restores PDGF inducibility to a 5' truncated MCP-1 gene. The 27-base element interacts with a PDGF-activated serine/threonine phosphoprotein that is detected only within the nucleus of PDGF-treated 3T3 cells. DNA binding of this phosphoprotein is activated by PDGF treatment with slow kinetics that match the time course of MCP-1 gene expression, and activation is not inhibited by cycloheximide. PDGF-activated binding to the 27-mer is shown to involve a single 30-kDa protein by UV-cross-linking analysis.

3T3 Cells↗
PubMed1993

Severe pulmonary oedema after venous air embolism.

We present a 59-yr-old Chinese male patient who developed acute pulmonary oedema and cardiovascular collapse following multiple episodes of venous air emboli while in the sitting position for removal of a cervical meningioma. The severity of the pulmonary oedema and cardiovascular disturbance were surprising. Postoperative ventilation and inotropic support were required and five litres of plasma were needed to replace the fluid lost as pulmonary oedema. We discuss the differential diagnosis of the pulmonary changes and review current ideas on the pathogenesis for pulmonary oedema following venous air embolism.

Carbon Dioxide↗
PubMed1993

Gastric pH and volume after oral fluids in the postpartum patient.

The aim of this study was to investigate the relationship between preoperative oral fluids and gastric pH and volume in women undergoing sterilization between one and five days postpartum. Fifty postpartum patients received 150 ml water approximately two to three hours before surgery while 50 postpartum and 50 non-pregnant women were fasted from midnight. After induction of anaesthesia, gastric contents were aspirated using a Salem sump tube and the gastric pH and volume were measured. There were no differences in intragastric pH and volume, median (range), among the postpartum fasted group, 1.19 (0.74-4.57), 22 (1-78) ml, postpartum water group 1.18 (0.70-6.4), 25.5 (3-66) ml and the non-pregnant group 1.27 (0.51-6.63), 25 (3-69) ml. There was no correlation between postpartum interval, 60 (12-120) hr, and intragastric pH or volume. It is concluded that oral water may be given safely two to three hours preoperatively to patients more than one day postpartum. Intragastric volume and acidity were not increased and the findings in postpartum patients were similar to those found in non-pregnant patients.

Adult↗
PubMed1993

Analgesia after caesarean section with intramuscular ketorolac or pethidine.

We compared, in a double-blind randomised study, intramuscular ketorolac 30 mg (n = 49) and intramuscular pethidine 75 mg (n = 51) for analgesia after elective caesarean section under general anaesthesia. Anaesthesia was induced with thiopentone and suxamethonium and maintained with atracurium, nitrous oxide and isoflurane. Intravenous fentanyl 100 micrograms was given after delivery of the neonate. In the recovery ward, patients who requested analgesia were allocated randomly to receive ketorolac 30 mg or pethidine 75 mg intramuscularly. Analgesia was assessed at intervals up to six hours, using a visual analogue scale and a four-point verbal scale, while duration of analgesia was taken as the time until the patient requested additional analgesia. There was no difference in the duration of analgesia between groups (Mann-Whitney test P = 0.27, Mantel-Haentszel test P = 0.17). Twenty-six patients in the ketorolac group and 17 patients in the pethidine group requested further analgesia by 90 minutes. However, four patients in the ketorolac group and six patients in the pethidine group requested no further analgesia within 24 hours. Pain VAS and overall assessment of analgesia was similar between groups, although more side-effects (nausea, dizziness) were noted in the pethidine group. Ketorolac 30 mg and pethidine 75 mg provided similar but variable quality of analgesia after caesarean section.

Adult↗
PubMed1990

Red cell distribution width in the detection of iron deficiency in maintenance hemodialysis patients.

Iron deficiency is a frequent complication in maintenance hemodialysis patients. Red cell distribution width (RDW) was recently used as an indicator in early detection of iron deficiency. One hundred and thirty nine patients maintained on hemodialysis were studied for the usefulness of RDW in detection of iron deficiency. Serum ferritin less than 30 ug/dl was defined as iron deficiency in these patients. Another 69 patients with iron deficiency not entering hemodialysis were chosen as a control group. The sensitivity of RDW elevation to detect iron deficiency in chronic hemodialysis patients was only 36.7% which was much lower than that of the control group (62.3%). However, it was still more sensitive than microcytosis in the detection of iron deficiency in chronic hemodialysis patients because none of them showed microcytosis. The specificity and positive predictive value of RDW elevation in respect to iron deficiency were 62.4% and 9.6% respectively. This study demonstrated that the use of RDW in the detection of iron deficiency in chronic hemodialysis patients was superior to mean corpuscular volume but still limited.

Erythrocyte Count↗
PubMed1989

Serum endorphin levels in uremic patients under maintenance hemodialysis.

We checked serum beta-endorphin levels in 17 chronic uremic patients under regular hemodialysis and compared them with the levels in 17 age-matched control subjects. Higher levels of serum beta-endorphin were found in uremic patients (22.54 +/- 6.20 pg/0.1 ml vs 9.42 +/- 5.19 pg/0.1 ml, p less than 0.001). There were no sex differences in both uremic patients (M: F = 21.04 +/- 7.53 pg/0.1 ml vs 23.59 +/- 5.25 pg/0.1 ml, p greater than 0.05) and normal control subjects (9.16 +/- 5.15 pg/0.1 ml vs 9.76 +/- 5.55 pg/0.1 ml, p greater than 0.05). No significant difference in the serum levels was noted between the patients with a hemodialysis history longer than two years (19.96 +/- 5.79 pg/0.1 ml vs 25.45 +/- 5.60 pg/0.1 ml, p greater than 0.05) and those with less than a two year's history (19.96 +/- 5.79 pg/0.1 ml vs 25.45 +/- 5.60 pg/0.1 ml, p greater than 0.05). Moreover, serum beta-endorphin levels were not altered after dialysis (22.54 +/- 6.20 pg/0.1 ml to 20.66 +/- 4.57 pg/0.1 ml, p greater than 0.05) by either acetate or bicarbonate dialysate (acetate vs bicarbonate = 20.83 +/- 5.03 pg/0.1 ml vs 20.13 +/- 3.14 pg/0.1 ml, p greater than 0.05). The role of beta-endorphin in the pathogenesis of uremic syndrome still requires further study.

Aged↗