Anesthesia and analgesia
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Anesthesia and analgesia · Oct 2002
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of the laryngeal tube with the laryngeal mask airway during routine surgical procedures.
The laryngeal mask airway (LMA; Laryngeal Mask Company, Henley-on-Thames, UK) is an established airway device, whereas the laryngeal tube (LT) is relatively new and therefore not as well investigated. Therefore, the purpose of the present prospective, randomized, controlled trial was to compare the LT with the LMA in routine clinical practice. In 50 patients undergoing general anesthesia for minor routine surgery, standardized anesthesia was induced and maintained with alfentanil and propofol. Patients were randomized to controlled ventilation (fraction of inspired oxygen = 0.4; fraction of inspired nitrous oxide = 0.6; tidal volume = 7 mL/kg; respiratory rate = 10 breaths/min) with the LT (n = 25) or the LMA (n = 25). Oxygen saturation was recorded before the induction of anesthesia and after the administration of oxygen. After 2 and 10 min of ventilation with the LT or LMA, oxygen saturation, end-expiratory carbon dioxide, expiratory tidal volume, and peak airway pressure were recorded. Capillary blood gas samples were taken before the induction of anesthesia and after 10 min of ventilation. Time of insertion and airway leak pressure of each device were measured. The time of insertion was comparable with both devices (LT versus LMA, median 21 s versus 19 s; P = not significant). Blood gas samples and ventilation variables revealed sufficient ventilation and oxygenation with either device (P = not significant). Peak airway pressure (LT, 17 +/- 3 cm H(2)O; LMA, 15 +/- 3 cm H(2)O) and airway leak pressure (LT, 36 +/- 3 cm H(2)O; LMA, 22 +/- 3 cm H(2)O) were significantly (P < 0.05) higher when using the LT compared with the LMA. In conclusion, using the LT and LMA resulted in comparable ventilation and oxygenation variables in this model of ASA physical status I and II patients undergoing routine surgical procedures. The newly developed LT may be a simple alternative device to secure the airway. ⋯ The laryngeal tube, a newly developed airway device, and the laryngeal mask airway were used to ventilate patients in the operating room. Both airway devices proved to be effective and safe; however, the laryngeal tube allowed greater airway pressure during ventilation.
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Anesthesia and analgesia · Oct 2002
Randomized Controlled Trial Comparative Study Clinical TrialThe analgesic effect of gabapentin and mexiletine after breast surgery for cancer.
We investigated the analgesic efficacy of mexiletine and gabapentin on acute and chronic pain associated with cancer breast surgery in 75 patients. They were randomized to receive, in a double-blinded manner, mexiletine 600 mg/d, gabapentin 1200 mg/d, or placebo for 10 days. Anesthesia was standardized, and all patients had access to routine postoperative analgesics on demand. The visual analog scale score assessed pain at rest and after movement. Three months later, all patients were interviewed to identify intensity of chronic pain and analgesic requirements. Mexiletine and gabapentin reduced codeine consumed from the second to tenth day by 50% (P = 0.029; P = 0.018 and P = 0.035 for mexiletine versus control and gabapentin versus control comparisons, respectively). Total paracetamol consumption was also reduced during the same time (P = 0.0085; P = 0.007 and P = 0.011 for the mexiletine and gabapentin groups when compared with the control, respectively). Pain at rest and after movement was reduced by both drugs on the third postoperative day. Pain after movement also was reduced by gabapentin between the second and fifth postoperative day. Three months later, the incidence of chronic pain, its intensity, and need for analgesics were not affected by either treatment. However, burning pain was more frequent in the control group (P = 0.033). ⋯ Patients undergoing breast surgery for cancer may develop chronic pain. We evaluated the effect of mexiletine and gabapentin on the acute and chronic pain after breast surgery for cancer. Both drugs reduced the postoperative analgesic requirements, and particularly, gabapentin reduced pain after movement. The overall incidence of chronic pain was unaffected except for burning pain.
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Anesthesia and analgesia · Oct 2002
Randomized Controlled Trial Clinical TrialThe effect of chronic oral desipramine on capsaicin-induced allodynia and hyperalgesia: a double-blinded, placebo-controlled, crossover study.
The tricyclic antidepressants are often used for the treatment of neuropathic pain. In this study, we evaluated one of these drugs on human cutaneous experimental pain. A randomized, double-blinded, placebo-controlled, crossover design methodology was conducted. Subjects participated in 2 14-day study sessions separated by a 7-day washout period. One session was with desipramine and one with placebo. At baseline, Day 7, and Day 15, quantitative sensory testing was performed to thermal and mechanical stimuli. On Day 15 only, intradermal capsaicin was injected on the volar aspect of the forearm followed by an assessment of pain and hyperalgesia. Oral desipramine had no significant effect on acute sensory thresholds, pain, secondary hyperalgesia, or flare response induced by intradermal capsaicin. Mean peak plasma levels of desipramine were within the therapeutic range for the treatment of depression. This study further supports a lack of effect of the tricyclic antidepressants on acute nociception and experimentally-induced secondary hyperalgesia. ⋯ Human experimental pain models have recently been developed; however, the efficacy of the tricyclic antidepressants (TCA) in these models has not been systematically studied. This investigation provides further validation of human experimental pain models and demonstrates that the chronic delivery of a TCA has no effect on human experimental pain.
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Anesthesia and analgesia · Oct 2002
Randomized Controlled Trial Clinical TrialPropofol in a medium- and long-chain triglyceride emulsion: pharmacological characteristics and potential beneficial effects.
Hypertriglyceridemia is a possible unwanted effect during long-term propofol sedation while using a formulation containing long-chain triglycerides (LCT) from soybean oil. The use of propofol formulated in a solvent consisting of medium-chain triglycerides (MCT) and LCT might reduce the risk. Because a new solvent may affect the pharmacological profile of propofol, in this prospective, randomized, controlled, and double-blinded study we compared the pharmacodynamic and kinetic characteristics of propofol diluted in MCT/LCT fat solution with those of propofol formulated in LCT fat emulsion. In addition, serum triglyceride levels were measured during and after the administration of both drugs. Thirty patients likely to require mechanical ventilation over at least 48 h were randomized to receive either propofol 2% MCT/LCT (Group 1) or propofol 2% LCT (Group 2). Infusion rates of propofol (2.34 +/- 0.83 mg. kg(-1). h(-1) in Group 1 versus 2.31 +/- 0.6 mg. kg(-1). h(-1) in Group 2), the plasma propofol concentrations during infusion (0.95 +/- 0.53 versus 0.98 +/- 0.32 micro g/mL), and the concentrations and arousal behavior after discontinuation of the drug did not show significant differences. Plasma triglyceride concentrations during sedation did not differ between the groups, whereas there was a tendency toward a more rapid triglyceride elimination in Group 1 after termination of the propofol administration. ⋯ Propofol diluted in an emulsion of medium- and long chain-triglycerides shows equivalent pharmacological properties during long-term sedation compared with its hitherto well known formulation containing long-chain triglycerides only. In addition, potential favorable effects on the plasma triglyceride profile could be found.
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Anesthesia and analgesia · Oct 2002
Randomized Controlled Trial Clinical TrialPropacetamol as adjunctive treatment for postoperative pain after cardiac surgery.
Postoperative pain management after cardiac surgery has been mainly based on parenteral opioids. However, because opioids have numerous side effects, coadministration of non-opioid analgesics has been introduced as a method of reducing opioid dose. In this prospective, randomized, double-blinded study, we evaluated the efficacy of propacetamol, an IV administered prodrug of acetaminophen (paracetamol), as an adjunctive analgesic after cardiac surgery. Seventy-nine patients scheduled for elective coronary artery bypass grafting were randomized to receive either propacetamol 2 g (n = 40) or placebo (n = 39) IV in 6-h intervals for 72 h. From the time of extubation, patients had access to an opioid (oxycodone) via a patient-controlled analgesia device. Pain was evaluated on a visual analog scale four times daily, whereas respiratory function tests (forced vital capacity, forced expiratory volume in 1 s, peak expiratory flow, and arterial blood gas measurements) were performed once a day. The prespecified primary efficacy variable (cumulative oxycodone consumption at the end of the 72-h postoperative period) was 123.5 mg (51.3 mg) (mean [SD]) in the propacetamol group and 141.8 mg (57.5 mg) in the placebo group (difference in mean, 18.3 mg = 13%; 95% confidence interval, 6.1-42.7 mg; P = 0.15). Pain scores did not differ between the groups at rest (P = 0.65) or during a deep breath (P = 0.72). The groups were also similar in terms of pulmonary function tests, postoperative bleeding, and hepatic function tests, and no significant differences were noted in the incidences of adverse effects. After completion of the study, apost hoc analysis was also performed analyzing the first 24 h as split into 6-h intervals. This analysis showed a significantly (P = 0.036) smaller consumption of oxycodone in the propacetamol group at 24 h (47.1 mg [20.7 mg] versus 57.9 mg [23.9 mg]; difference in mean, 10.8 mg; 95% confidence interval, 0.7-20.9 mg). In conclusion, propacetamol did not enhance opioid-based analgesia in coronary artery bypass grafting patients, nor did it decrease cumulative opioid consumption or reduce adverse effects within 3 days after surgery. However, post hoc analysis showed that oxycodone requirement was reduced within the first 24 h in the propacetamol group. ⋯ This is the first placebo-controlled study to investigate the efficacy of propacetamol as a complementary analgesic to opioids after cardiac surgery. Propacetamol did not enhance analgesia, nor did it decrease cumulative opioid consumption or reduce adverse effects in a dose of 2 g given every sixth hour for 3 days after surgery.