Biomedical subjects

M S Mok

Publications and source records attributed to M S Mok.

At least 19 recordsLinked to original sources

PubMed1994

Combination of intramuscular Ketorolac and low dose epidural morphine for the relief of post-caesarean pain.

Epidural morphine produces profound analgesia but also causes many adverse effects in a dose-dependent manner. This double-blind, randomized, prospective study evaluated the analgesic efficacy and safety of low dose (2 mg) epidural morphine in combination with 30 mg intramuscular (IM) Ketorolac, a non-steroidal anti-inflammatory drug with potent analgesic activity, in patients suffering pain after caesarean surgery. Ninety parturients who received epidural anaesthesia in the postoperative period were divided into 3 equal groups: group A received epidural morphine 2 mg plus IM placebo; group B received epidural morphine 2 mg plus IM Ketorolac 30 mg; and group C received epidural saline placebo plus IM Ketorolac 30 mg. All patients were observed for pain relief, vital signs and adverse effects for 24 hours post drug administration. Results showed that group B had statistically significant superior pain relief to that of the other 2 groups. The incidence of adverse effects was similar between those of group A and B. We concluded that the addition of Ketorolac by IM administration enhanced the analgesic effect of low dose (2 mg) epidural morphine in the relief of post-caesarean pain without potentiating its adverse effects.

Adult↗

PubMed1994

Effectiveness of flumazenil on return of cognitive functions after a general anesthetic.

Benzodiazepines used intra-operatively can occasionally cause prolonged sedation. Flumazenil (Romazicon) is an imidazobenzodiazepine that functions as a benzodiazepine receptor antagonist. This clinical investigation was designed to evaluate the efficacy and of intravenous flumazenil in reversing the central effects of midazolam after a general anesthetic using midazolam for maintenance. 30 ASA I-III inpatients entered and completed this study. All were interviewed preoperatively and baseline performance on a battery of psychomotor tests was obtained. Parameters measured included an assessment of sleep status, vital signs, responsiveness to verbal stimuli, quality of speech, facial expression, eye coordination, recognition of a picture card, finger-finger-to-nose (FFN) coordination and overall discharge readiness. General anesthesia was induced with midazolam. Midazolam and fentanyl were the primary maintenance agents combined with N2O and O2 (70:30) and a limited concentration of isoflurane. In the recovery room the test drug was administered in a double-blinded, randomized manner. 20 patients received flumazenil (F), the rest placebo (P). Testing was done at times 0, 5, 15, 30, 60, 120, and 180 min in the PACU. Memory testing consisted of recall of study pictures at 180 min and recognition on the first postoperative day. Demographic data were similar for both groups with the exception of age. The F group had a higher mean composite score (comprising responsiveness to verbal stimuli, speech, facial expression and eye coordination) and better FFN scores at 5, 15, and 30 min (p < 0.01). There were no significant differences between groups at other times. F patients identified pictures better at 5 and 15 min (p < 0.004 and 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Electrophysiological actions of alfentanil: intracellular studies in the rat locus coeruleus neurones.

1. The electrophysiological effects of alfentanil on 156 neurones of the rat locus coeruleus were investigated by use of intracellular recordings from the in vitro brain slice preparation. 2. Bath application of alfentanil (5-100 nM) reversibly decreased the firing rate of all neurones tested in a dose-dependent manner, with an IC50 4.1.nM. 3. Based on inhibition of the spontaneous firing rate, alfentanil was 22 times more potent than morphine. 4. At 100 nM, alfentanil produced a complete inhibition of firing of all neurones tested (n = 62); the inhibition was accompanied by a membrane hyperpolarization 17.0 +/- 0.8 mV (range 6.1-30.3 mV, n = 62) and a reduction in input resistance 26.4 +/- 1.7% (range 6.5-53%, n = 51). 5. The effects of alfentanil were antagonized by naloxone, with a dissociation equilibrium constant of 2.7 +/- 0.4 nM (n = 6). 6. The reversal potential for the alfentanil-induced hyperpolarization was -110 +/- 2 mV (n = 9), which is approximately the potassium equilibrium potential. 7. The alfentanil-induced hyperpolarization was blocked by caesium chloride and barium chloride. 8. These results indicate that alfentanil binds to mu-opioid receptors on the cell membrane of neurones of the locus coeruleus. This leads to opening of the inward-going rectification potassium channels, resulting in the observed hyperpolarization of the membrane.

Alfentanil↗

PubMed1992

Combination of low-dose epidural morphine and intramuscular diclofenac sodium in postcesarean analgesia.

Epidural morphine is used for postcesarean analgesia, and nonsteroidal antiinflammatory drugs are frequently administered to relieve uterine cramps after vaginal delivery. To assess the efficacy of a combination of low-dose epidural morphine and intramuscular diclofenac sodium in postcesarean analgesia, a double-blind, randomized study was conducted. Epidural anesthesia was given to 120 parturients who were randomly allocated into four treatment groups: group A received normal saline solution, 10 mL epidurally and 3 mL intramuscularly (IM); group B received 10 mL of epidural saline solution and 75 mg (3 mL) of diclofenac IM; group C received 2 mg of morphine in 10 mL of epidural saline solution and 3 mL of saline solution IM; and group D received 2 mg of morphine in 10 mL of epidural saline solution and 75 mg of diclofenac IM. Epidural injections were given after delivery of the placenta, and IM injections were given on arrival in the recovery room. Verbal analogue pain scores were recorded at 2, 4, 8, 12, 18, and 24 h after epidural injection. Subjective scores of overall pain relief were also recorded at 24 h. Results showed that scores of overall pain relief were significantly better in group D compared with group A, B, or C (P less than 0.05). Groups A and B required more supplemental meperidine than groups C and D. None of the subjects in group D requested supplemental analgesia. Compared with the other three groups, group D experienced a better analgesic effect for both wound pain and uterine cramping pain from 4 to 18 h (P less than 0.05). Incidence of nausea or vomiting, or both, and pruritus occurred more frequently in groups C and D compared with group A or B (P less than 0.05). No bradypnea was observed during the study period. Diclofenac alone was not effective in postcesarean analgesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Comparison of repeat doses of intramuscular ketorolac tromethamine and morphine sulfate for analgesia after major surgery.

A multicenter, randomized, double-blind, parallel study in 542 patients with moderate or severe postoperative pain compared the analgesic efficacy and safety of intramuscular ketorolac 30 mg (324 patients), morphine 6 mg (110 patients), and morphine 12 mg (108 patients) administered as needed as often as every 2 hours for a maximum of 20 doses or 5 days. The efficacy of ketorolac 30 mg was comparable to that of morphine 12 mg on every efficacy measure (average pain intensity, average pain relief, mean overall medication rating, and percentage of patients withdrawing because of inadequate relief). Ketorolac was statistically superior to morphine 6 mg for average pain intensity and mean overall rating. Ketorolac-treated patients had fewer adverse events than those who received either morphine dose.

Adolescent↗

PubMed1990

[Does flumazenil antagonize the anesthetic effect of ketamine, etomidate or thiopental?].

The effect of flumazenil, a benzodiazepine antagonist, was assessed in a random, double-blind clinical study in which each of the four groups of surgical outpatients comprising 20 in each was given either ketamine 100 mg (K), etomidate 20 mg (E), thiopental 300 mg (T) or flunitrazepam 4 mg (F) for induction of anesthesia. On emergence, patients in each group were randomly given 2cc of either 2 coded solutions, one of which contained 0.2 mg flumazenil and the other of which was normal saline. Following injection of coded solution, all patients were assessed at 0, 5, 15, 30, 60 and 120 min for wakefulness. All 10 patients of group F who received flumazenil were alert and able to recall at 5 min, whereas in group T this was noted from 15 to 30 min. Patients of group E and K responded alike in a manner as of those who received normal saline placebo with onset of wakefulness at 30 and 60 min respectively. These results confirm that flumazenil antagonizes flunitrazepam (within 5 min) and also indicate that the antagonizing effect occurs 30 min following injection for thiopental, suggestive of some cross-reactivity between these two drugs.

Adult↗

PubMed1989

Tonazocine mesylate in postoperative pain patients: a double-blind placebo controlled analgesic study.

One hundred-fifty post-operative adult patients with moderate to severe pain were enrolled into this analgesic efficacy study comparing single doses of tonazocine mesylate, a new mixed agonist-antagonist opioid analgesic, with morphine. The patients were randomly assigned to five treatment groups: tonazocine mesylate 2, 4, 8 mg; morphine sulfate 10 mg and a placebo group. The results showed mean total pain relief scores for tonazocine 4 mg were nearly identical with that of morphine sulfate 10 mg while 8 mg of tonazocine were superior to 10 mg of morphine. All the active medication groups were superior to the placebo group (P less than 0.02) for both pain intensity and pain relief. Relative potency determined by the dose response indicates that 3.2 mg of tonazocine is equivalent to 10 mg of morphine. Drowsiness was the main adverse reaction seen in all active treatment groups. Tonazocine mesylate appears to be a potent analgesic with promising clinical usefulness and warrants further study.

Adolescent↗

PubMed1989

[Comparative study of the antagonizing effect to flunitrazepam between Ro 15-1788 and physostigmine].

In a double blind, randomized, placebo-controlled study, thirty patients who had received flunitrazepam during operation were divided into three groups. At the end of surgery, one group was given a placebo, one group was given Ro 15-1788 (Benzodiazepine antagonist) and a third group was given physostigmine. Each group was assessed at the end of 5 minutes, 15 minutes, 30 minutes 60 minutes and 120 minutes for alertness/sedation, recall, recognition and motor coordination. At the end of 5 and 15 minutes, the patients who had received Ro 15-1788 showed a statistically significant difference in alertness/sedation from those in the other two groups (p less than 0.01). This group also showed a statistically significant difference in motor coordination at the end of 5 minutes (p less than 0.05). There was no significant difference in recognition or recall at anytime. Physostigmine showed no significant difference change from the control group at anytime in every aspect. In conclusion, Ro 15-1788 is an effective antagonist to the alertness/sedation of flunitrazepam, but physostigmine is not.

Adult↗

PubMed1989

[Pulmonary lavage for alveolar proteinosis. A case report].

Pulmonary alveolar proteinosis is characterized by an amorphous lipoproteinaceous material filling the acini of the lung, resulting in hypoxemia. At present, the most effective treatment for alveolar proteinosis is lung lavage. Here, we report the first case in Taiwan treated with this method. A 38-year-old male with a 6-month history of cough and increasing breathlessness was transferred from another hospital. On admission, his arterial oxygen tension was 51 mmHg when breathing room air. Chest X-ray films showed diffuse infiltration of both lung fields. Transbronchoscopic lung biopsy was consistent with alveolar proteinosis, therefore the patient was submitted to pulmonary lavage. Under general anesthesia, the patient was intubated with a left-sided double lumen endotracheal tube, and lavage of the right lung was repeated with 0.9% saline until the washing became clear. At the end of the procedure, the patient was extubated after making strong respiratory efforts. Several days later, the left lung was lavaged using the same technique. The mechanical washing of amorphous material from alveoli by pulmonary lavage is of great benefit in relieving hypoxemia. Judicious use of lung lavage is effective and safe for patient with alveolar proteinosis.

Adult↗

PubMed1989

[Effect of increasing amounts of clonidine during hyperbaric tetracaine spinal anesthesia].

The effect of adding clonidine to hyperbaric tetracaine spinal anesthesia was investigated in 60 ASA class I-II patients scheduled for orthopedic and lower abdominal surgery. The subjects were randomly allocated into 4 groups. All patients received tetracaine 10 mg in 10% glucose solution 2 mL. Patients in group 1 received above medication and were the control group, patients in the other groups received tetracaine plus increasing dosages of clonidine: 15 microgram (Gr.2), 30 microgram (Gr.3), and 45 microgram (Gr.4). The segmental level of sensory loss was tested by the pinprick method using a 23 G needle. The three clonidine groups had significantly increased in the sensory regression time to L1 level (by 42, 47, 60% respectively), and also had significantly increased motor complete recovery time (by 48, 70, 74% respectively), but the incidence of hypotension and bradycardia was increased in the clonidine 0.045 mg group. It is concluded that addition of 15 or 30 microgram clonidine may be useful as a means of increasing the duration of hyperbaric tetracaine spinal anesthesia.

Adult↗

PubMed1988