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Biomedical subjects

M S Mok

Publications and source records attributed to M S Mok.

At least 55 records · Page 3Linked to original sources

Sequential cardiorespiratory patterns of anesthetic induction with ketamine in critically ill patients.

Hemodynamic and O2 transport effects of ketamine anesthesia were evaluated in 22 critically ill patients. After placement of radial and pulmonary artery catheters, simultaneous measurement were made of cardiac output, intravascular pressures, arterial and mixed venous gases, saturations, pH, and Hct; cardiorespiratory values then were calculated for a preinduction control period and sequentially at frequent intervals over a 15-min observation period. In general, there was an early progressive increase in HR, cardiac index (CI), arterial and venous pressures, stroke work, and O2 delivery (DO2); O2 consumption (VO2) and O2 extraction (O2 Ext) decreased. In general, ketamine produced an inotropic cardiac response, but these responses were not uniform; a relatively small percentage had reduced pressures, flow, and reduced myocardial performance that were related to hypovolemia and associated medical conditions.

Anesthesia↗

Multidose/observational, comparative clinical analgetic evaluation of buprenorphine.

Ninety-eight patients completed a double-blind, multidose, randomized parallel study in which buprenorphine (Temgesic) was compared to morphine. Drugs were administered at approximately equipotent intramuscular doses for a maximum of three days for the relief of moderate to severe postoperative pain. The two drugs exhibited similar profiles with pain relief evident at 1/2 hour, peaking at 1 hour, and decreasing to slight relief at 4-5 hours, with no significant differences for time to remedication. The most frequent side effect was somnolence. One patient suffered sudden chest pain shortly after an injection of morphine, and one patient had moderate hypoventilation after buprenorphine; both patients recovered uneventfully. Overall, both drugs provided good or excellent analgesia in 80 per cent of the patients in this unique multidose/observational study. Thus, these data and the reported lack of withdrawal symptoms and the absence of physical dependence liability suggest that buprenorphine may have a role in the management of chronic pain.

Adult↗

Butorphanol and promethazine as pre-anaesthetic medication.

An open evaluation of a combination of butorphanol (1 or 2 mg), promethazine (25 or 50 mg) and atropine (0.5 mg) in 109 adult consenting patients was carried out to determine their safety and efficacy for preanaesthetic medication. All patients were kept under direct surveillance from before intramuscular medication until they were in satisfactory condition post-operatively for discharge from the recovery room. The medications employed did not disturb the blood pressure, pulse rate or respiration rate in any of the patients. None complained of nausea or dizziness while only one was slightly excited. Sedation was rated as satisfactory in 97 per cent, and 90 per cent were free of apprehension. In addition, global evaluation of the premedication by the investigator was rated good to excellent in 99 per cent of the patients. On the basis of these observations, the combination of butorphanol with promethazine and atropine appears safe and useful for pre-anaesthetic medication.

Adolescent↗

Tracheal cylindroma: anaesthetic management.

A tracheal cylindroma in a lady aged 56 yr was excised. The problems of tracheal and carinal resection, and an anaesthetic technique which obviates the use of cardiopulmonary bypass are described.

Anesthesia, General↗

Absence of "recurarization" in patients with demonstrated prolonged neuromuscular block.

The possibility of "recurarization" after antagonism of the competitive neuromuscular block with anticholinesterases was studied. Observations were made on the time-course of the block in five patients at risk from recurarization because of multiple organ failure and who demonstrated unusually prolonged blockade. In none of these patients did the block recur. We conclude that, provided spontaneous recovery of neuromuscular transmission has made progress before the antagonism, and that the patient does not deteriorate or become exhausted afterwards, recurarization is unlikely.

Adult↗

Treatment of obesity by acupuncture.

Twenty-four subjects ranging from 5 to 33% above ideal weight were weighted during a 3-week control period, and then treated for the successive 9 weeks with acupuncture therapy given in three different loci, and in random order for 3-week periods. The acupuncture needles were placed in unilateral loci used by oriental acupuncturists for weight loss, in the same loci bilaterally, and in unilateral loci not used by acupuncturists for weight loss. No undesirable effects were noted. No treatment was associated with weight reduction significant at the 0.05 confidence level. A study involving guinea pigs was run parallel with the above clinical protocol and also demonstrated no effect of ear acupuncture on weight loss.

Acupuncture Therapy↗

Local anesthetic effect of tramadol, metoclopramide, and lidocaine following intradermal injection.

BACKGROUND AND OBJECTIVES: We observed clinically that tramadol and metoclopramide appear to have local anesthetic action. Tramadol is a central-acting analgesic. Metoclopramide is a commonly used antiemetic. The local anesthetic effect of tramadol in reducing propofol injection pain has never been mentioned, although it was speculated with metoclopramide. METHODS: We conducted a double-blind, placebo-controlled study by injecting tramadol or metoclopramide intradermally in 10 healthy volunteers (5 men, 5 women; age 25-56 years). Each subject received 0.5 mL of four solutions in random order on the volar side of the forearm. These solutions were 25 mg tramadol, 5 mg metoclopramide, 5 mg lidocaine, and 0.5 mL normal saline. Pain on injections and the degree of local anesthesia (tested by pinprick, light touch, and cold) at each site was reported on a 0-3 scale at designed time intervals. RESULTS: Like 1% lidocaine, tramadol and metoclopramide demonstrated loss of sensation for pinprick, light touch, and cold for 15 minutes after intradermal injection (P < .01 ). CONCLUSIONS: Intradermal tramadol or metoclopramide can produce local anesthetic effect.

Adult↗

Enhancement of analgesic effect of intrathecal neostigmine and clonidine on bupivacaine spinal anesthesia.

BACKGROUND AND OBJECTIVES: Intrathecal administration of neostigmine has been shown to produce analgesia in both animals and humans. The concurrent administration of intrathecal neostigmine and clonidine has been reported to produce no neurotoxicity in sheep. The purpose of the present study was to evaluate the efficacy and safety of the combining intrathecal neostigmine and clonidine for the relief of pain in patients after cesarean delivery. METHODS: After giving their consents, 80 parturients who were scheduled for cesarean delivery during spinal anesthesia were enrolled by a double-blind randomized design into four groups: bupivacaine group (n = 20) received intrathecal (i.t.) 10 mg bupivacaine; bupivacaine + neostigmine group (n = 19) received i.t. 10 mg bupivacaine + 50 microg neostigmine; bupivacaine + clonidine group (n = 20) received i.t. 10 mg bupivacaine + 150 microg clonidine; and bupivacaine + both (n = 21) received i.t. 10 mg bupivacaine + 50 microg neostigmine + 150 microg clonidine. The maximum spread of anesthesia, duration of analgesia and motor block, vital signs, and incidence of adverse effects were recorded for 14 hours postinjection. Fifty milligrams intramuscular meperidine was given as a rescue analgesic whenever patient's pain score was greater than 5/10 by the visual analog scale. RESULTS: The demographic data were similar for all four groups. Bupivacaine + both group had a significantly higher maximum spread of anesthesia of 23.3 +/- 2.9 segments than bupivacaine group of 20.5 +/- 2.9 segment. Bupivacaine + both group showed a later onset of postsurgical pain of 6.5 +/- 1.5 hours as compared to bupivacaine group of 1.3 +/- 0.6 hours. The pain score in bupivacaine + both group was significantly lower than that of bupivacaine group during the first 10 hours. The 24-hour meperidine consumption also was lower in bupivacaine + both group than that of bupivacaine group. However, motor block was significantly prolonged from 3.5 +/- 1.1 hours in bupivacaine group to 7.1 +/- 1.6 hours in bupivacaine + both group. In addition, other side effects such as nausea and vomiting and dizziness were significantly increased in bupivacaine + both group. CONCLUSION: Our study showed that the combination of 150 microg i.t. clonidine and 50 microg neostigmine provided longer postsurgical analgesia than with either drug used alone. However, this combination also produced significantly more adverse effects of prolonged motor block and nausea and vomiting. A further study combining the two study drugs but using a lower dose of i.t. neostigmine (e.g., 25 microg) is recommended.

Analgesics, Non-Narcotic↗

The peripheral analgesic effect of meperidine in reducing propofol injection pain is not naloxone-reversible.

BACKGROUND AND OBJECTIVES: Meperidine is frequently used in general anesthesia and perioperative analgesia. In addition to its opioid action, meperidine possesses some local anesthetic properties. A preliminary study using the tourniquet venous retention technique found meperidine to be more effective in reducing propofol injection pain than fentanyl or morphine, both of which were slightly better than placebo. This study was undertaken to evaluate whether this peripheral analgesic effect of meperidine is affected by naloxone. METHODS: In a randomized, double-blind manner, after venous occlusion with a tourniquet, meperidine 40 mg was given intravenously to patients in group A (n = 31), meperidine 40 mg followed by naloxone 0.04 mg to group B (n = 32), meperidine 40 mg followed by naloxone 0.2 mg to group C (n = 30), and normal saline placebo to group D (n = 30). The venous retention of drug(s) was maintained for 1 minute, followed by tourniquet release and intravenous administration of propofol 100 mg. Pain assessment was made immediately after the propofol injection. RESULTS: All three groups given meperidine had significantly less propofol injection pain (P < .01 ) than the group given saline placebo, and there was no difference among groups A, B, and C. CONCLUSION: The peripheral analgesic effect of meperidine in reducing propofol injection pain is not mediated by its opioid activity.

Adjuvants, Anesthesia↗