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Biomedical subjects

D C Moriarty

Publications and source records attributed to D C Moriarty.

At least 19 recordsLinked to original sources
PubMed2006

Fentanyl and clonidine as adjunctive analgesics with levobupivacaine in paravertebral analgesia for breast surgery.

The addition of fentanyl or clonidine to levobupivacaine was evaluated in patients undergoing breast surgery under general anaesthesia with intra- and postoperative paravertebral analgesia. Patients were randomly allocated to four groups: Group L received 19 ml bolus levobupivacaine 0.25% plus 1 ml saline followed by an infusion of levobupivacaine 0.1%; Group LF received 19 ml bolus levobupivacaine 0.25% plus fentanyl 50 microg followed by an infusion of levobupivacaine 0.05% with fentanyl 4 microg x ml(-1); Group LC received 19 ml bolus levobupivacaine 0.25% plus clonidine 150 microg followed by an infusion of levobupivacaine 0.05% with clonidine 3 microg x ml(-1); Group C (control) received general anaesthesia without paravertebral analgesia. All groups received postoperative i.v. morphine patient controlled analgesia (PCA). Although mean (SD) postoperative PCA morphine consumption was decreased in LF [7.9 (4.1) mg] and LC [5.9 (3.5) mg]vs L [27.7 (8.6) mg] or C patients [21.7 (5.5) mg], p < 0.01, paravertebral fentanyl and clonidine were associated with significantly increased vomiting and hypotension, respectively.

Adult↗
PubMed2005

Inhibition of the stress response to breast cancer surgery by regional anesthesia and analgesia does not affect vascular endothelial growth factor and prostaglandin E2.

Angiogenesis is essential for breast cancer metastases formation and is mediated by vascular endothelial growth factor (VEGF) and prostaglandin E2 (PGE2). We hypothesized that serum levels of VEGF and PGE2 are increased by the stress response to breast cancer surgery and attenuated by paravertebral anesthesia and analgesia (PVAA). Thirty women undergoing mastectomy were enrolled in this prospective, randomized study, to receive general anesthesia (GA) and postoperative opioid analgesia (morphine 0.1 mg/kg bolus and patient-controlled infusion) or GA and PVAA (72-h infusion). All patients received rectal diclofenac. Venous blood samples were taken preoperatively and at 4 and 24 h postoperatively for serum glucose, cortisol, C-reactive protein, VEGF, and PGE2. PVAA inhibited the surgical stress response, as indicated by significantly less plasma glucose, cortisol, and C-reactive protein. VEGF and PGE2 values did not differ significantly between the groups. Mean (SD) percentage change in VEGF at 4 and 24 h respectively were 3% +/- 44% versus 9% +/- 80%, P=0.29 and 5% +/- 43% versus -10% +/- 63%, P=0.41 for patients with combined general and PVAA and GA alone, respectively. Mean percentage change in postoperative PGE2 at 4 and 24 h respectively was 10% +/- 17% versus 11% +/- 69%, P=0.29 and 34% +/- 19% versus 47% +/- 18%, P=0.15. We conclude that despite inhibiting the surgical stress response, PVAA had no effect on serum levels of putative breast cancer angiogenic factors, VEGF and PGE2.

Adult↗
PubMed2002

Intraperitoneal pethidine versus intramuscular pethidine for the relief of pain after laparoscopic cholecystectomy: randomized trial.

Laparoscopic cholecystectomy is widely used and may be performed as an ambulatory procedure. We undertook a randomized comparison of the benefits of intraperitoneal pethidine compared with intramuscular pethidine for postoperative analgesia following laparoscopic cholecystectomy. A series of 100 consecutive American Society of Anesthesiologists (ASA) I or II patients were randomly assigned to intramuscular pethidine (54 patients) or intraperitoneal pethidine (46 patients). Each was combined with intraperitoneal bupivacaine. The primary endpoints were the pain and nausea scores at intervals after operation. All recruited patients completed the study. Pain scores at rest and upon movement were significantly lower in the group receiving the intraperitoneal pethidine at each of the time periods examined (pain at rest at 4 hours: 1.6 +/- 0.8 vs. 2.4 +/- 0.9 cm; p < 0.001; pain upon movement at 4 hours: 2.1 +/- 0.9 vs. 3.1 +/- 1.2 cm; p < 0.001). The total dose of pethidine administered via patient-controlled analgesia (PCA) during the first 24 hours after surgery was also significantly lower in this group (total dose 50.9 +/- 3.9 vs. 55.9 +/- 4.4 mg; p < 0.001). There were no significant differences in the respiratory rate at any of the time periods. Intraperitoneal pethidine analgesia was superior to an equivalent dose of intramuscular pethidine for the relief of postoperative pain in patients undergoing laparoscopic cholecystectomy. This was achieved at the expense of increased nausea but no significant increase in vomiting. The accessibility of this route of analgesia administration has implications for patients undergoing laparoscopic procedures, particularly with the recent trend toward increased use of ambulatory techniques.

Adult↗
PubMed2001

Pulmonary embolism following tonsillectomy.

Acute post-operative pulmonary embolism is a serious potentially life-threatening complication which is not anticipated in young patients undergoing non-major surgery. We report a case in which a 32-year-old previously healthy woman developed a major pulmonary embolism following tonsillectomy. Subsequent investigations revealed the presence of an occult malignancy. This case highlights the role of paraneoplastic hypercoagulable states in the aetiology of venous thromboembolism and the importance of thromboprophylaxis in the presence of confirmed or suspected malignancy. To our knowledge no case of major pulmonary embolism occurring after tonsillectomy has been previously reported.

Acute Disease↗
PubMed2000

Antiproliferative actions of inhalational anesthetics: comparisons to the valproate teratogen.

The antiproliferative potential of the volatile anesthetics isoflurane, enflurane and sevoflurane was determined and compared to the valproate teratogen. The in vitro system employed, a G1 phase proliferative arrest endpoint in C6 glioma, has served previously to discriminate agents with known teratogenic potential in vivo. Based on estimated IC(50) values that were within twice the estimated minimum aveolar concentration value, the rank antiproliferative potency of the inhalational anesthetics employed was isoflurane=enflurane>>sevoflurane. Flow cytometric analysis of growth-arrested cell populations failed to reveal specific accumulation in any cell cycle phase and the lack of a G1 phase-specific effect was confirmed by the absence of a transient, time-dependent sialylation event in synchronized cells. The antiproliferative mechanism of volatile anesthetics, and valproate, was mediated at hydrophobic binding sites, as increasing the hydration sphere of the drug-micelle complex, using the hygroscopic qualities of the dimethylsulfoxide vehicle, completely reversed this effect. Our findings suggest inhalational anesthetics lack the specific in vitro characteristics of the valproate teratogen.

Anesthetics, Inhalation↗
PubMed2000

An assessment of the value of intraperitoneal meperidine for analgesia postlaparoscopic tubal ligation.

UNLABELLED: Patients undergoing laparoscopic procedures may experience postoperative pain. The intraperitoneal (IP) administration of drugs is controversial but has proven effective in some studies for the relief of postoperative pain. However, some investigators have not been able to confirm the analgesic efficacy of IP local anesthetics. The administration of IP opioids for the relief of postoperative pain has received little attention. At the end of laparoscopic tubal ligation, 100 patients received 80 mL of 0.125% bupivacaine with 1:200,000 epinephrine IP and 50 mg of meperidine either IP or IM. Postoperative pain scores were measured at rest and with movement. Pain scores were significantly lower in the group receiving the IP meperidine both at rest (P: < 0.01) and with movement (P: < 0.05). We conclude that the combination of intraperitoneal bupivacaine and intraperitoneal meperidine was better than the combination of IP bupivacaine and IM meperidine for postoperative analgesia in patients undergoing laparoscopic tubal ligation. IMPLICATIONS: The combination of bupivacaine and meperidine delivered to the intraperitoneal cavity proved superior to equivalent doses of intraperitoneal bupivacaine and IM meperidine for postoperative pain relief in patients undergoing laparoscopic tubal ligation. Intraperitoneal delivery of analgesia proved effective in this study and merits further study and more widespread use.

Adult↗
PubMed2000

Effects of the combination of halothane and serotonin uptake blockers on synaptic transmission in the rat dentate gyrus in vitro.

Although the exact basis of their action remains unknown, volatile agents affect noradrenergic and serotoninergic systems. Imipramine and fluoxetine have documented effects on these neurotransmitter transmission systems. Given the common sites of action of these antidepressants and halothane, we examined their individual and combined effects on tonic excitatory post-synaptic potentials (EPSPs) and frequency dependent blockade in the rat dentate gyrus in vitro. Extracellular recordings of field EPSPs were maintained from the dentate gyrus, in the presence of picrotoxin (100 microM). Stimulation at 30 Hz (200 ms) allowed investigation of frequency dependent blockade. Once a stable equilibrium was established, halothane, imipramine and fluoxetine were administered via the perfusate and recordings were made. Halothane produced a dose dependent reduction in EPSP amplitude (EC50 0.28 mM; n = 12). Imipramine (1-10 microM) potentiated the EPSP amplitude (148.2 +/- 8.2%; imipramine 1 microM; n = 6). Fluoxetine (0.5-10 microM) reduced EPSP amplitude to 83.7 +/- 22.1% of control (n = 6). In the presence of halothane 0.2 mM, imipramine reduced the EPSP amplitude to 56.5 +/- 9.9% of control (imipramine 10 microM; n = 6; p < 0.05 compared with imipramine alone). Halothane (0.2 mM) demonstrated frequency dependent blockade. However, neither imipramine nor fluoxetine showed use dependent inhibition at the doses investigated. When combined with halothane 0.2 mM, fluoxetine 10 microM demonstrated frequency dependent blockade at the sixth pulse in the train compared with controls (13.8 +/- 4.7% vs 38.1 +/- 8.3%; n = 6; p < 0.05). The halothane-imipramine combination did not exhibit use dependent blockade greater than controls. The reversal of imipramine-induced EPSP potentiation by the preapplication of halothane has not been previously reported. It may be due to modulation of noradrenergic transmission by halothane. The frequency dependent blockade produced by the combination of fluoxetine 10 microM and halothane may be mediated by a nonspecific membrane effect on 5-HT uptake. These differing effects underline the broad action of volatile agents on synaptic mechanisms.

Anesthetics, Inhalation↗
PubMed1999

The effect of intravenous tenoxicam on pruritus in patients receiving epidural fentanyl.

In this prospective randomised study, pruritus and pain were evaluated in patients undergoing abdominal surgery during which epidural fentanyl was administered. All patients had an epidural catheter inserted at the time of surgery. Epidural fentanyl 100 micrograms was administered intra-operatively and infused at a concentration of 2 micrograms.ml-1 for 48 h postoperatively. All patients received a standard anaesthetic and, in addition, the study group had a 20 mg bolus of tenoxicam intravenously, intra-operatively. Patients receiving tenoxicam demonstrated significantly lower pruritus and pain scores at 30 min, 2, 4, 8 and 24 h postoperatively as well as reduced pethidine requirements for breakthrough pain in the first 24 h. In conclusion, tenoxicam 20 mg significantly reduces the incidence and severity of postoperative pruritus in patients who received peri-operative epidural fentanyl. In addition, it significantly reduces pain and further analgesic requirements postoperatively.

Abdomen↗
PubMed1999

The effect of rectal diclofenac on pruritus in patients receiving intrathecal morphine.

In this prospective randomised study, pruritus and pain were evaluated in patients undergoing abdominal surgery in which intrathecal morphine was administered. Each patient received intrathecal morphine 0.3 mg prior to induction, followed by a standard anaesthetic. The patients were randomly allocated to one of two groups. One group received 100 mg of rectal diclofenac immediately post-induction. Patients receiving diclofenac had significantly lower pruritus scores at 30 min (p = 0.0076), 2, 4, 8 and 24 h postoperatively, as well as significantly reduced pain scores at each time point (p < 0.0001 at each study interval). Morphine consumption in the first 24 h was also significantly lower in this group. In conclusion, rectal administration of diclofenac significantly reduces the incidence and severity of postoperative pruritus. It also significantly reduces pain and further analgesic requirements postoperatively.

Abdomen↗
PubMed1999

The combined effects of halothane and lamotrigine on excitatory postsynaptic potentials and use-dependent block in the rat dentate gyrus in vitro.

UNLABELLED: Halothane affects synaptic transmission in the rat hippocampus with a 50% effective dose (ED50) correlating with clinical figures for minimum alveolar anesthetic concentration (MAC). Halothane dose-dependently suppresses glutamate receptor-mediated excitatory postsynaptic potentials (EPSPs) in the rat hippocampus. It also inhibits voltage-gated Na+ channels. The anticonvulsant lamotrigine acts as a Na+ channel antagonist and inhibits glutamate release after Na+ channel activation. Given their known similar sites of action, the combination of halothane and lamotrigine may alter the inhibition produced by either drug alone. Extracellular recordings of field EPSPs were obtained from the dentate gyrus in the presence of 100 microM picrotoxin (to block GABAA receptors). Stimulation at 30 Hz (200 ms, pulse duration 0.1 ms, six pulses) allowed us to investigate use-dependent block (UDB). Once a stable equilibrium was established, halothane and lamotrigine were administered via the perfusate, and recordings were collected. Both halothane (n = 12) and lamotrigine (n = 6) exhibited reversible inhibition of the EPSP (ED50 0.28 mM [1.2%] and 100 microM, respectively) at low-frequency stimulation. Slices (n = 6) exposed to halothane 0.2 mM (0.75%), then to lamotrigine, showed reduced sensitivity compared with lamotrigine alone. Halothane 0.2 mM potentiated the control UDB (Pulse 6:31% +/- 11% control versus 20.5% +/- 2.5% halothane 0.75%; P < 0.05; n = 6). Lamotrigine had no effect on control UDB. The combination (n = 6) did not alter UDB effects compared with controls or lamotrigine alone. Halothane may reduce the effect of lamotrigine on glutamate release, either at the receptor or via effects at the inactivated Na+ channel. The site of interaction requires further examination. IMPLICATIONS: The general and local anesthetic drugs halothane and lamotrigine act at both the glutamate receptor and the Na+ channels and, in our experiments, independently inhibited synaptic transmission at low-frequency stimulation. Although halothane potentiated control use-dependent block, lamotrigine had no effect. Halothane attenuated the inhibitory dose-dependent effects of lamotrigine on synaptic transmission at a low frequency. The clinical importance of this interaction in patients presenting for anesthesia remains unanswered.

Anesthetics, Inhalation↗
PubMed1998

The laryngeal mask airway reduces blood flow in the common carotid artery bulb.

PURPOSE: The introduction of the laryngeal mask airway (LMA) has had a major impact on anaesthetic practice in the last ten years. Previous authors have demonstrated pressures equivalent to mean arterial blood pressure within the cuff of the LMA. This study examined the effects of cuff inflation on the cross sectional area, flow and velocity of blood flow at the level of the carotid sinus. METHODS: Seventeen patients scheduled to have LMAs inserted as part of routine anaesthetic management were recruited into the study. Measurements of the common carotid artery bulb area, peak velocity and blood flow were performed upon LMA cuff inflation and deflation using a 5 MHz pulse wave Doppler probe. RESULTS: Deflation of the cuff resulted in an increase in the cross sectional area (from 0.58 +/- 0.05 to 0.64 +/- 0.04 cm2; P < 0.005), an increase in blood flow (from 65.6 +/- 5.6 to 73.9 +/- 5.6 cm3.sec-1; P < 0.05) and a slight but non significant increase in velocity of blood flow. CONCLUSION: This study demonstrates that inflation of the cuff on the LMA results in a decrease in carotid bulb cross sectional area which results in a decrease in blood flow.

Adult↗
PubMed1998

Anaesthetic depth at induction. An evaluation using clinical eye signs and EEG polysomnography.

We describe the stages of non-REM sleep induced by anaesthesia with sevoflurane 8% in oxygen and relate these stages to clinical eye positions. We explored John Snow's observation (1847) that 'when voluntary movement ceases, with the eyes fixed in an upward gaze during the gas induction of anaesthesia, the patient is protected against the risk of mental suffering' (awareness). Unpremedicated ASA 1 patients undergoing elective tonsillectomy were studied using EEG polysomnographic principles and clinical eye movement tracking. The results expressed as median and range were: latency to stage 1 sleep 4.5 min [2.5-7.5], stage 2 sleep 5 min [3.5-8.5], stage 3 sleep 5.5 min [4-12] and stage 4 sleep 6 min [4.5-15.5]. Eye position 5, the point of no further eye movement, was reached after 9 min [5.5-18.5]. This was significantly longer than the time taken to reach the stage 4 sleep EEG, p < 0.01, supporting Snow's observation and encouraging investigation into eye movement tracking technology as a potential monitor of anaesthetic depth.

Adolescent↗
PubMed1998

Nefiracetam prevents propofol-induced anterograde and retrograde amnesia in the rodent without compromising quality of anesthesia.

BACKGROUND: Propofol is a short-acting intravenous anesthetic agent. However, cognitive function remains depressed for several hours thereafter. We have evaluated the ability of nefiracetam, a novel cognition-enhancing agent, to alleviate propofol-induced amnesia in a rodent model of learning. METHODS: Rats were trained in a one-trial, step-through, light-dark passive avoidance paradigm. Propofol (10 and 75 mg/kg) was administered by the intraperitoneal route at 15 min before training and separately at increasing times in the immediate 0-6 h post-training period (100 and 150 mg/kg). Nefiracetam, 9 mg/kg, was administered by the intraperitoneal route 1 h before training. Animals were tested for recall at the 12 h post-training time, and after their killing, immunocytochemistry was used to determine the increase in hippocampal neuronal polysialylation, an event associated with memory consolidation. Induction and duration of anesthesia induced by propofol was determined using tail pinch and pedal withdrawal reflexes. RESULTS: Propofol-induced anterograde amnesia occurred in a dose-dependent manner. Induction of retrograde amnesia required a higher dose of propofol, which anesthetized the animals and was effective only in the immediate 3-h post-training period. In the absence of any evident effect on the onset or duration of anesthesia, nefiracetam prevented both forms of propofol-induced amnesia and preserved the learning-associated changes of neuronal polysialylation state. CONCLUSIONS: The ability of nefiracetam to prevent propofol-induced anterograde and retrograde amnesia is proposed to be indirect and to result from modulation of gene transcription in a manner that initiates a cascade of events involving protein synthesis leading to synaptic growth associated with the formation of the long-term memory trace.

Amnesia↗